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Sample records for ascorbic acid inhibits

  1. Macrokinetics of magnesium sulfite oxidation inhibited by ascorbic acid.

    Science.gov (United States)

    Lidong, Wang; Yongliang, Ma; Wendi, Zhang; Qiangwei, Li; Yi, Zhao; Zhanchao, Zhang

    2013-08-15

    Magnesia flue gas desulfurization is a promising process for small to medium scale industrial coal-fired boilers in order to reduce sulfur dioxide emissions, in which oxidation control of magnesium sulfite is of great importance for the recycling of products. Effects of four inhibitors were compared by kinetic experiments indicating that ascorbic acid is the best additive, which retards the oxidation process of magnesium sulfite in trace presence. The macrokinetics of magnesium sulfite oxidation inhibited by ascorbic acid were studied. Effects of the factors, including ascorbic acid concentration, magnesium sulfite concentration, oxygen partial pressure, pH, and temperature, were investigated in a stirred reactor with bubbling. The results show that the reaction rate is -0.55 order in ascorbic acid, 0.77 in oxygen partial pressure, and zero in magnesium sulfite concentration, respectively. The apparent activation energy is 88.0 kJ mol(-1). Integrated with the kinetic model, it is concluded that the oxidation rate of magnesium sulfite inhibited by ascorbic acid is controlled by the intrinsic chemical reaction. The result provides a useful reference for sulfite recovery in magnesia desulfurization. PMID:23692683

  2. Ascorbic Acid

    Science.gov (United States)

    Ascorbic acid is used to prevent and treat scurvy, a disease caused by a lack of vitamin C in ... Ascorbic acid comes in extended-release (long-acting) capsules and tablets, lozenges, syrup, chewable tablets, and liquid drops to ...

  3. Inhibition of free radical-induced erythrocyte hemolysis by 2-O-substituted ascorbic acid derivatives.

    Science.gov (United States)

    Takebayashi, Jun; Kaji, Hiroaki; Ichiyama, Kenji; Makino, Kazutaka; Gohda, Eiichi; Yamamoto, Itaru; Tai, Akihiro

    2007-10-15

    Inhibitory effects of 2-O-substituted ascorbic acid derivatives, ascorbic acid 2-glucoside (AA-2G), ascorbic acid 2-phosphate (AA-2P), and ascorbic acid 2-sulfate (AA-2S), on 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative hemolysis of sheep erythrocytes were studied and were compared with those of ascorbic acid (AA) and other antioxidants. The order of the inhibition efficiency was AA-2S> or =Trolox=uric acid> or =AA-2P> or =AA-2G=AA>glutathione. Although the reactivity of the AA derivatives against AAPH-derived peroxyl radical (ROO(*)) was much lower than that of AA, the derivatives exerted equal or more potent protective effects on AAPH-induced hemolysis and membrane protein oxidation. In addition, the AA derivatives were found to react per se with ROO(*), not via AA as an intermediate. These findings suggest that secondary reactions between the AA derivative radical and ROO(*) play a part in hemolysis inhibition. Delayed addition of the AA derivatives after AAPH-induced oxidation of erythrocytes had already proceeded showed weaker inhibition of hemolysis compared to that of AA. These results suggest that the AA derivatives per se act as biologically effective antioxidants under moderate oxidative stress and that AA-2G and AA-2P may be able to act under severe oxidative stress after enzymatic conversion to AA in vivo. PMID:17854711

  4. Ascorbic acid inhibition of Candida albicans Hsp90-mediated morphogenesis occurs via the transcriptional regulator Upc2.

    Science.gov (United States)

    Van Hauwenhuyse, Frédérique; Fiori, Alessandro; Van Dijck, Patrick

    2014-10-01

    Morphogenetic transitions of the opportunistic fungal pathogen Candida albicans are influenced by temperature changes, with induction of filamentation upon a shift from 30 to 37°C. Hsp90 was identified as a major repressor of an elongated cell morphology at low temperatures, as treatment with specific inhibitors of Hsp90 results in elongated growth forms at 30°C. Elongated growth resulting from a compromised Hsp90 is considered neither hyphal nor pseudohyphal growth. It has been reported that ascorbic acid (vitamin C) interferes with the yeast-to-hypha transition in C. albicans. In the present study, we show that ascorbic acid also antagonizes the morphogenetic change caused by hampered Hsp90 function. Further analysis revealed that Upc2, a transcriptional regulator of genes involved in ergosterol biosynthesis, and Erg11, the target of azole antifungals, whose expression is in turn regulated by Upc2, are required for this antagonism. Ergosterol levels correlate with elongated growth and are reduced in cells treated with the Hsp90 inhibitor geldanamycin (GdA) and restored by cotreatment with ascorbic acid. In addition, we show that Upc2 appears to be required for ascorbic acid-mediated inhibition of the antifungal activity of fluconazole. These results identify Upc2 as a major regulator of ascorbic acid-induced effects in C. albicans and suggest an association between ergosterol content and elongated growth upon Hsp90 compromise. PMID:25084864

  5. Oxygen dependency of one-electron reactions generating ascorbate radicals and hydrogen peroxide from ascorbic acid.

    Science.gov (United States)

    Boatright, William L

    2016-04-01

    The effect of oxygen on the two separate one-electron reactions involved in the oxidation of ascorbic acid was investigated. The rate of ascorbate radical (Asc(-)) formation (and stability) was strongly dependent on the presence of oxygen. A product of ascorbic acid oxidation was measurable levels of hydrogen peroxide, as high as 32.5 ?M from 100 ?M ascorbic acid. Evidence for a feedback mechanism where hydrogen peroxide generated during the oxidation of ascorbic acid accelerates further oxidation of ascorbic acid is also presented. The second one-electron oxidation reaction of ascorbic acid leading to the disappearance of Asc(-) was also strongly inhibited in samples flushed with argon. In the range of 0.05-1.2 mM ascorbic acid, maximum levels of measurable hydrogen peroxide were achieved with an initial concentration of 0.2 mM ascorbic acid. Hydrogen peroxide generation was greatly diminished at ascorbic acid levels of 0.8 mM or above. PMID:26593628

  6. 21 CFR 582.5013 - Ascorbic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ascorbic acid. 582.5013 Section 582.5013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5013 Ascorbic acid. (a) Product. Ascorbic acid. 1 Amino acids listed in this subpart may...

  7. 21 CFR 582.3013 - Ascorbic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ascorbic acid. 582.3013 Section 582.3013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... Ascorbic acid. (a) Product. Ascorbic acid. (b) Conditions of use. This substance is generally recognized...

  8. 21 CFR 182.8013 - Ascorbic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ascorbic acid. 182.8013 Section 182.8013 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8013 Ascorbic acid. (a) Product. Ascorbic acid. (b) Conditions of use. This substance is generally recognized as safe when used...

  9. Drug Nanoparticle Formulation Using Ascorbic Acid Derivatives

    OpenAIRE

    Kunikazu Moribe; Waree Limwikrant; Kenjirou Higashi; Keiji Yamamoto

    2011-01-01

    Drug nanoparticle formulation using ascorbic acid derivatives and its therapeutic uses have recently been introduced. Hydrophilic ascorbic acid derivatives such as ascorbyl glycoside have been used not only as antioxidants but also as food and pharmaceutical excipients. In addition to drug solubilization, drug nanoparticle formation was observed using ascorbyl glycoside. Hydrophobic ascorbic acid derivatives such as ascorbyl mono- and di-n-alkyl fatty acid derivatives are used either as drugs...

  10. 21 CFR 182.3013 - Ascorbic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ascorbic acid. 182.3013 Section 182.3013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... acid. (a) Product. Ascorbic acid. (b) Conditions of use. This substance is generally recognized as...

  11. Kinetic determination of ascorbic acid in pharmaceuticalsamples

    OpenAIRE

    S.S. Mitic; G. Z. MILETIC; S. M. MILETIC; D.A. Kostic

    1999-01-01

    A kinetic method is described for the determination of ascorbic acid based on its inhibiting effect on the Mn(II) catalysis of the oxidation of Malachite Green with potassium periodate. The sensitivity of the method is 35.4 ng cm-3. The relative error ranges between 2.66 and 7.45% for the concentration interval 35.4 to 354 ng cm-3. Kinetic equations are proposed for the investigated process. The effects of certain foreign ions upon the reaction rate were determined for the assessment of the s...

  12. Preservative Effect of Na2SO3 and Ascorbic Acid on the Inhibition of Clanis bilineata Meat Melanosis

    Directory of Open Access Journals (Sweden)

    Hongbing Wang

    2013-09-01

    Full Text Available Melanosis formation in the Meat of Clanis Bilineata Larvae (MCBL treated with Na2SO3 in combination with Ascorbic Acid (AA was monitored during frozen storage of 6 months. No melanosis occurred in MCBL when the meat was treated with 0.05% Na2SO3 in combination with 0.04% AA (p<0.05. Total viable number of Mesophilic and psychrophilic bacterial in MCBL treated with Na2SO3 (0.05% in combination with AA (0.04% decreased, while that in the control MCBL increased. Results indicated that the treatment developed in this study was a promising way to preserve MCBL during extended frozen storage.

  13. Bioavailability of ascorbic acid in horses.

    Science.gov (United States)

    Snow, D H; Frigg, M

    1990-12-01

    The bioavailability of ascorbic acid administered to thoroughbreds by intramuscular injection was investigated. For intramuscular injection two preparations were studied, and the percentage bioavailability up to 24 h of 10 g of ascorbic acid was 95% +/- 22 in four horses and 60% in two horses with preparations A and B, respectively. Bioavailability at 24 h in three horses injected subcutaneously with 10 g of preparation B was 82%. Intramuscular injection of both preparations was apparently well tolerated while subcutaneous injection of preparation B (pH 6.0) was associated with marked irritancy. In a cross-over trial in seven thoroughbreds the effect of 13 or 15 days of oral administration of crystalline ascorbic acid (20 g) or ascorbyl palmitate (47 g) on plasma ascorbic-acid concentrations was investigated. Marked differences occurred between individuals. There was a greater increase in plasma ascorbic-acid concentration with ascorbyl palmitate compared to ascorbic acid at 6 and 24 h following administration. In two horses there was no increase in plasma ascorbic acid at 6 h following either oral preparation. The finding of lowered plasma ascorbic-acid concentrations following a period of supplementation warrants further investigation to assess its significance. PMID:2287031

  14. Ascorbic acid inhibits ferric nitrilotriacetate induction of ornithine decarboxylase, DNA synthesis, oxidative stress, and hepatotoxicity in rats.

    Science.gov (United States)

    Ansar, S; Iqbal, M

    2015-11-01

    Ascorbic acid (AA) is a naturally occurring phenolic compound with antioxidant properties used in food, cosmetics, and pharmaceutical products. In this study, the effect of AA on ferric nitrilotriacetate (Fe-NTA)-induced hepatotoxicity in rats has been examined. Fe-NTA alone enhances ornithine decarboxylase activity to 4.5-fold and tritiated thymidine incorporation in DNA to 3.6-fold in livers compared with the corresponding saline-treated controls. The enhanced ornithine decarboxylase activity and DNA synthesis showed a reduction to 3.02- and 1.88-fold, respectively, at a higher dose of 2 mg AA per day per animal, compared with the Fe-NTA-treated groups. Fe-NTA treatment also enhanced the hepatic microsomal lipid peroxidation to 1.7-fold compared to saline-treated controls. These changes were reversed significantly in animals receiving pretreatment of AA. The present data shows that AA can reciprocate the toxic effects of Fe-NTA and can serve as a potent chemopreventive agent to suppress oxidant-induced tissue injury and hepatotoxicity in rats. PMID:23863956

  15. Ascorbic acid absorption in Crohn's disease. Studies using L-[carboxyl-14C]ascorbic acid

    International Nuclear Information System (INIS)

    Total body pool and intestinal absorption of ascorbic acid were studied in 12 patients undergoing operation for Crohn's disease (six with fistulae and six without) and in six control patients undergoing operation for reasons other than Crohn's disease. L-[carboxyl-14C]Ascorbic acid, 0.19-0.40 megabecquerels (MBq), was given orally. After a period of equilibration, the labeled ascorbic acid was flushed out of the patient's body tissues using large doses of unlabeled ascorbic acid. Intestinal absorption of ascorbic acid, assessed from the total cumulative urinary 14C recovery, was found to be similar in patients with fistulizing Crohn's disease (73.9 +/- 8.45%), those without fistulas (72.8 +/- 11.53%), and in controls (80.3 +/- 8.11%). Total body pools of ascorbic acid, calculated using the plasma 14C decay curves, were similar in patients with Crohn's disease with fistulas (17.1 +/- 5.91 mg/kg), patients without fistulas (9.6 +/- 3.58 mg/kg), and in controls (13.3 +/- 4.28 mg/kg). The results indicate that ascorbic acid absorption is normal in patients with both fistulizing and nonfistulizing Crohn's disease. The results suggest that routine supplements of vitamin C are not necessary unless oral ascorbic acid intake is low

  16. Impulsive mathematical modeling of ascorbic acid metabolism in healthy subjects.

    Science.gov (United States)

    Bachar, Mostafa; Raimann, Jochen G; Kotanko, Peter

    2016-03-01

    In this work, we develop an impulsive mathematical model of Vitamin C (ascorbic acid) metabolism in healthy subjects for daily intake over a long period of time. The model includes the dynamics of ascorbic acid plasma concentration, the ascorbic acid absorption in the intestines and a novel approach to quantify the glomerular excretion of ascorbic acid. We investigate qualitative and quantitative dynamics. We show the existence and uniqueness of the global asymptotic stability of the periodic solution. We also perform a numerical simulation for the entire time period based on published data reporting parameters reflecting ascorbic acid metabolism at different oral doses of ascorbic acid. PMID:26724712

  17. Sensitization of Salmonella typhi towards gamma-radiation by ascorbic acid

    International Nuclear Information System (INIS)

    The sensitivity of a S. typhi culture to ?-radiation has been examined. The D10 value, when the culture was irradiated in phosphate buffer, was found to be 70 krad. The addition of ascorbic acid (at a concentration of 0.57 mM) during irradiation, sensitized this organism quite markedly towards ?-radiation. This was evident from the observation that the D10 value was reduced to 20 krad when cells were irradiated in the ascorbic acid. Ascorbic acid was converted to its oxidized form during the radiation process. Irradiation under nitrogen instead of air inhibited the sensitization afforded by ascorbic acid. The population of cells surviving after irradiation in the presence of ascorbic acid showed a higher activity of catalase than its buffer-irradiated counterpart. The implication of the role of hydrogen peroxide (one of the possible intermediates formed during the oxidation of ascorbic acid) in sensitization is discussed. (author)

  18. 21 CFR 172.315 - Nicotinamide-ascorbic acid complex.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Nicotinamide-ascorbic acid complex. 172.315 Section... HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.315 Nicotinamide-ascorbic acid complex. Nicotinamide-ascorbic acid complex may be safely used in accordance with the following prescribed...

  19. Higher transcription levels in ascorbic acid biosynthetic and recycling genes were associated with higher ascorbic acid accumulation in blueberry.

    Science.gov (United States)

    Liu, Fenghong; Wang, Lei; Gu, Liang; Zhao, Wei; Su, Hongyan; Cheng, Xianhao

    2015-12-01

    In our preliminary study, the ripe fruits of two highbush blueberry (Vaccinium corymbosum L.) cultivars, cv 'Berkeley' and cv 'Bluecrop', were found to contain different levels of ascorbic acid. However, factors responsible for these differences are still unknown. In the present study, ascorbic acid content in fruits was compared with expression profiles of ascorbic acid biosynthetic and recycling genes between 'Bluecrop' and 'Berkeley' cultivars. The results indicated that the l-galactose pathway was the predominant route of ascorbic acid biosynthesis in blueberry fruits. Moreover, higher expression levels of the ascorbic acid biosynthetic genes GME, GGP, and GLDH, as well as the recycling genes MDHAR and DHAR, were associated with higher ascorbic acid content in 'Bluecrop' compared with 'Berkeley', which indicated that a higher efficiency ascorbic acid biosynthesis and regeneration was likely to be responsible for the higher ascorbic acid accumulation in 'Bluecrop'. PMID:26041210

  20. Transglucosylation of ascorbic acid to ascorbic acid 2-glucoside by a recombinant sucrose phosphorylase from Bifidobacterium longum.

    Science.gov (United States)

    Kwon, Taeyeon; Kim, Cheong Tae; Lee, Jong-Hoon

    2007-04-01

    A novel transglycosylation reaction from sucrose to L-ascorbic acid by a recombinant sucrose phosphorylase from Bifidobacterium longum was used to produce a stable L-ascorbic acid derivative. The major product was detected by HPLC, and confirmed to be 2-O-alpha-D-glucopyranosyl-L-ascorbic acid by LC-MS/MS analysis. PMID:17216298

  1. Transport of ascorbic acid and dehydroascorbic acid by pancreatic islet cells from neonatal rats

    DEFF Research Database (Denmark)

    Zhou, A; Farver, O; Thorn, N A; Nielsen, Jens Høiriis

    involves a saturable process (estimated Km 17.6 microM). Transport was inhibited by ouabain, phloridzin, cytochalasin B, amiloride and probenecid. Glucose inhibited or stimulated uptake, depending on the length of incubation time of the cells. The uptake of dehydroascorbic acid was linearly dependent on.......14.17.3). The enzyme needs ascorbic acid for activity as well as copper and molecular oxygen. The present work shows that pancreatic islet cells prepared from overnight cultures of isolated islets from 5-7-day-old rats accumulate 14C-labelled ascorbic acid by a Na(+)-dependent active transport mechanism which...

  2. Ascorbic acid enhances the inhibitory effect of aspirin on neuronal cyclooxygenase-2-mediated prostaglandin E2 production

    OpenAIRE

    Candelario-Jalil, E.; Akundi, R. S.; Bhatia, H. S.; Lieb, K.; Appel, K; Munoz, E; Hull, M.; Fiebich, B. L.

    2007-01-01

    In the present study, we show that ascorbic acid dose-dependently inhibited interleukin-1beta (IL-1beta)-mediated PGE2 synthesis in the human neuronal cell line, SK-N-SH. Furthermore, in combination with aspirin, ascorbic acid augmented the inhibitory effect of aspirin on PGE2 synthesis. However, ascorbic acid had no synergistic effect along with other COX inhibitors (SC-58125 and indomethacin). The inhibition of IL-1beta-mediated PGE2 synthesis by ascorbic acid was not due ...

  3. The influence of ascorbic acid on the oxygen consumption and the heat production by the cells of wheat seedling roots with their mitochondrial electron transport chain inhibited at complexes I and III

    International Nuclear Information System (INIS)

    The influence of exogenous ascorbic acid (AsA) on oxidative phosphorylation was studied using wheat seedling roots. Treatment of them with AsA stimulated the rates of oxygen consumption and the heat production and caused a decrease of the respiratory coefficient. The increase in respiration was prevented by inhibitors of ascorbate oxidase, diethyldithiocarbamate (DEDTC), and of cytochrome oxidase, cyanide (KCN). Exogenous AsA sharply stimulated the rate of oxygen consumption of roots when complexes I and III of the mitochondrial electron transport chain were inhibited by rotenone and antimycin A, respectively, while the rates of heat production did not change significantly. It is concluded that AsA is a potent energy substrate, which can be used in conditions of failing I and III complexes in the mitochondrial electron transport chain

  4. Ascorbic acid and its effect on the skin of Bufo regularis.

    Science.gov (United States)

    Sadek, I A; Abdelmegid, N

    1982-01-01

    Skin papillomas were observed in the majority of toads when painted with 1 mg of 7,12-dimethyl-benz (alpha) anthracene (DMBA) dialy for 8 weeks. Animals injected with 10 mg/kg/day of ascorbic acid into the dorsal lymph sac showed tumor inhibition when painted with the same dose level of DMBA for 8 weeks. Tumor regression occurred in those animals receiving 10 mg/kg/day of ascorbic acid for 8 weeks. PMID:6813785

  5. Ascorbic acid monoglucoside as antioxidant and radioprotector

    International Nuclear Information System (INIS)

    Ascorbic acid monoglucoside (AsAG), a glucoside derivative of ascorbic acid, has been examined for its antioxidant and radioprotective abilities. AsAG neutralized 1, 1 diphenyl -2-picryl-hydrazyl (DPPH), a stable free radical in a concentration dependent manner thus indicating its antioxidant ability. AsAG protected mice liver tissues in vitro from peroxidative damage in lipids (measured as TBARS) resulting from 25Gy ? irradiation. It also protected plasmid pBR322 DNA from gamma-radiation induced strand breaks as evidenced from studies on agarose gel electrophoresis of the plasmid DNA after radiation exposure. Oral administration of AsAG to mice prior to whole body gamma radiation exposure (4Gy) resulted in a reduction of radiation induced lipid peroxides in the liver tissue indicating in vivo radiation protection of membranes. Pulse radiolysis studies indicated that AsAG offered radioprotection by scavenging free radicals. The rate constants for the reactions OH and N3 radicals with AsAG were determined to be 6.4 x 109 dm3 mol-1 s-1 and 2.3 x 109 dm3 mol-1 s-1, respectively at pH 7. It was observed that AsAG radicals undergo conjugation as the pH of the solution is raised to 11 in the case of a one-electron oxidation reaction. As the OH· radical adds to the ring, the conjugation effect starts appearing at pH 10. (author)

  6. Heavy metals influence on ascorbic acid level

    Science.gov (United States)

    Kamaldinov, E. V.; Patrashkov, S. A.; Batenyeva, E. V.; Korotkevich, O. S.

    2003-05-01

    It is well known that heavy metals (HM) are extremely dangerous pollutants influencing to metabolism in animals' organisms. The vitamin C is one of the most important metabolites taking part in many biochemical processes. We studied the influence of main essential HM-Zn and Cu as well as the based supertoxical elements - Cd and Pd on ascorbic acid level in serum. The studies were carried out in Tulinskoe farm of Novosibirsk region. The objects of investigations were piglets (2 month after weaning) and 6-month pigs of Early Ripe Meat breed. The levels of HM in bristle were found by stripping voltammetric analysis using the TA-2 analyzer. Vitamin C content was determined by I.P. Kondrakhin (1985) method using 2,2-dipyridyl. The significant negative correlations between Pb, Cd content and vitamin C (-0.46 ± 0.18, -0.47 ± 0.19) in 6-month pigs were determined. The tendencies of negative correlation between all HM levels in hair and ascorbic acid level in plasma of piglets were revealed. Thus, the obtained correlations let us to suppose that all studied HM influence on 1-gulono-gamma-lactone oxidase and other vitamin C metabolism enzymes activity.

  7. Ascorbic acid study in citrus juice: effect of preservative

    International Nuclear Information System (INIS)

    This paper reports the effect of preservative on ascorbic acid extracted from freshly plucked oranges. Colorimetric method was used for the determination of ascorbic. Determination of some inorganic elements like sodium, potassium and lithium were also determined by flame photometry. The preservative was found to have a beneficial effect on the retention of ascorbic acid, particularly when used in high concentration. Metal content, particularly potassium did no alter significantly during preservation for duration of one month. (author)

  8. Depletion of Ascorbic Acid Restricts Angiogenesis and Retards Tumor Growth in a Mouse Model

    Directory of Open Access Journals (Sweden)

    Sucheta Telang

    2007-01-01

    Full Text Available Angiogenesis requires the deposition of type IV collagen by endothelial cells into the basement membrane of new blood vessels. Stabilization of type IV collagen triple helix depends on the hydroxylation of proline, which is catalyzed by the iron-containing enzyme prolyl hydroxylase. This enzyme, in turn, requires ascorbic acid to maintain the enzyme-bound iron in its reduced state. We hypothesized that dietary ascorbic acid might be required for tumor angiogenesis and, therefore, tumor growth. Here, we show that, not surprisingly, ascorbic acid is necessary for the synthesis of collagen type IV by human endothelial cells and for their effective migration and tube formation on a basement membrane matrix. Furthermore, ascorbic acid depletion in mice incapable of synthesizing ascorbic acid (Gulo-/- dramatically restricts the in vivo growth of implanted Lewis lung carcinoma tumors. Histopathological analyses of these tumors reveal poorly formed blood vessels, extensive hemorrhagic foci, and decreased collagen and von Willebrand factor expression. Our data indicate that ascorbic acid plays an essential role in tumor angiogenesis and growth, and that restriction of ascorbic acid or pharmacological inhibition of prolyl hydroxylase may prove to be novel therapeutic approaches to the treatment of cancer.

  9. THE EFFECTS OF ASCORBIC ACID ON MEMBRANE TRANSPORT OF GLUCOSE

    Directory of Open Access Journals (Sweden)

    Zoran Pavlovic

    2004-01-01

    Full Text Available The level of glycemia and ascorbic acid was tested of oral glucose-tolerance test (OGTT. This test was done on thirty healthy normoglycemic adult women, between 18 and 30 years of age, who showed no clinical signs of endocrine disturbances.At the beginning of the experiment the level of ascorbic acid and the level of glycemia were determined twelve hours after the last meal. In the following seven days eash of the examined women was given, beside the usual nourishment, 1.000 mg ascorbic acid (two times a day of 500 mg with breakfast and lunch. The level of ascorbic acid the last taken dosage of ascorbic acid. The achieved results of OGTT at the beginning and in the end of the test showed the ascorbic acid in the dosage of 1.000 mg/per day for seven days intensified the level glycemia during OGTT.This hyperglycemy is probably the consequence of the receptor obstruction in cellular membrane by ascorbic acid.

  10. Synthesis of New L-Ascorbic Ferulic Acid Hybrids

    OpenAIRE

    Sylvain Rault; Jean-Charles Lancelot; Marc-Antoine Bazin; Anne Sophie Voisin-Chiret

    2007-01-01

    A feasibility and chemical study of the coupling conditions of L-ascorbic acidwith ferulic acid derivatives are described on the basis of the known synergistic effects ofmixtures of various antioxidants. Novel L-ascorbic ferulic hybrids linked at the C-3hydroxyl group were prepared with the aim to protect the alcohol function and the enediolsystem.

  11. Synthesis of New L-Ascorbic Ferulic Acid Hybrids

    Directory of Open Access Journals (Sweden)

    Sylvain Rault

    2007-11-01

    Full Text Available A feasibility and chemical study of the coupling conditions of L-ascorbic acidwith ferulic acid derivatives are described on the basis of the known synergistic effects ofmixtures of various antioxidants. Novel L-ascorbic ferulic hybrids linked at the C-3hydroxyl group were prepared with the aim to protect the alcohol function and the enediolsystem.

  12. Ascorbic Acid Contents in Chili Peppers (Capsicum L.)

    OpenAIRE

    Owk ANIEL KUMAR; Sape SUBBA TATA

    2009-01-01

    The genus Capsicum commonly known as chili pepper is a major spice crop and is almost cosmopolitan in distribution. The nutritive value of chili pepper is largely determined by ascorbic acid content. The fruits at five ripening stages viz., (M1, M2, M3, M4 and M5) from seventeen cultivars of Capsicum annuum L and one cultivar of Capsicum frutescens L were analyzed for ascorbic acid content. Among eighteen genotypes the C. annuum var. IC: 119262(CA2) showed higher ascorbic acid content (mg/100...

  13. Radiation protection by ascorbic acid in sodium alginate solutions

    Energy Technology Data Exchange (ETDEWEB)

    Aliste, A.J.; Mastro, N.L. Del [Center of Radiation Technology, IPEN/CNEN/SP, University City, 05508-000 Sao Paulo (Brazil)]. E-mail: ajaliste@ipen.br

    2004-07-01

    Alginates are gelling hydrocolloids extracted from brown seaweed used widely in the nourishing and pharmaceutical industries. As alginic acid gellification retard food entrance in the stomach alginate is an additive used in diets. The objective of this work was to study the protective action of the ascorbic acid in alginate solutions against the action of {sup 60} Co gamma radiation. One % (w/v) solutions of alginate had been used and concentrations of ascorbic acid varied from 0 to 2.5% (w/v). The solutions were irradiated with doses up to 10 kGy. Viscosity/dose relationship and the p H of the solutions at 25 Centigrade were determined. Ascorbic acid behaved as an antioxidant against radiation oxidative shock in this model system of an irradiated viscous solution. Besides its radiation protective role on alginate solutions ascorbic acid promoted a viscosity increase in the range of concentrations employed. (Author)

  14. Effect of Ascorbic Acid on Lipid Peroxidation Induced by Ceftazidime

    Directory of Open Access Journals (Sweden)

    Devbhuti P*,1

    2011-01-01

    Full Text Available Lipid peroxidation is the oxidative deterioration of polyunsaturated lipids which is a free radical related process and responsible for thedevelopment of many diseases and disorders like diabetes mellitus, hypertension, cancer etc. End products of lipid peroxidation aremalondialdehyde (MDA, 4-hydroxy-2-nonenal (4-HNE, etc. which are the ultimate mediator of toxicity. Antioxidants have the capability toinhibit lipid peroxidation. Keeping in mind this fact, the present in vitro study was carried out to evaluate lipid peroxidation induction potential of ceftazidime, a cephalosporin antibiotic and its suppression with ascorbic acid considering some laboratory markers of lipid peroxidation like MDA, 4-HNE and reduced glutathione (GSH. Goat liver was used as the lipid source. After treatment of the liver homogenate with drug and/or antioxidant the levels of 4-HNE, MDA and GSH were estimated in different samples at different hours of incubation. The results showed that the drug ceftazidime could significantly induce lipid peroxidation and the antioxidant ascorbic acid has the capability to inhibit ceftazidime-inducedlipid peroxidation.

  15. Ascorbic acid metabolism in diabetes mellitus.

    Science.gov (United States)

    Pecoraro, R E; Chen, M S

    1987-01-01

    Competition for membrane transport between glucose and ascorbic acid (AA) has been shown in vitro in human lymphocytes, granulocytes, and fibroblasts. Therefore, we examined the effects of acute administration of i.v. glucose on AA levels in mononuclear (MNL) and polymorphonuclear leukocytes (PMN) and on leukocyte chemotaxis. Plasma glucose and AA, MNL AA, PMN AA, and chemotaxis by MNL and PMN were measured before and after i.v. glucose in fasted normal male volunteers. A decline in AA occurred in PMN as well as MNL, but decreases in AA induced acutely by transient hyperglycemia were not associated with changes in chemotaxis. However, under conditions of prolonged hyperglycemia maintained by a glucose clamp technique, significant changes (p less than 0.01) in chemotaxis by both PMN and MNL were observed after 210 and 240 min, with changes in chemotaxis to several chemoattractants significantly correlated with decreases in intracellular AA after 240 min (p less than 0.05). These results are consistent with the hypothesis that chronic hyperglycemia may be associated with intracellular deficits of leukocyte AA, an impaired acute inflammatory response, and altered susceptibility to infection and faulty wound repair in patients with diabetes. PMID:3475999

  16. Ascorbic acid improves the antioxidant activity of European grape juices by improving the juices' ability to inhibit lipid peroxidation of human LDL in vitro

    DEFF Research Database (Denmark)

    Landbo, Anne-Katrine Regel; Meyer, Anne Boye Strunge

    2001-01-01

    Antioxidant activities of red and white European grape juices towards copper induced lipid oxidation of human low-density lipoproteins (LDL) were examined in vitro. LDL lipid peroxidation was assessed spectrophotometrically by monitoring the development of conjugated lipid hydroperoxides at 234 nm. Red grape juice concentrate inhibited lipid peroxidation of LDL by prolonging the lag phase by 2.7 times relative to a control when evaluated at a total phenolic concentration of 10 muM gallic acid eq...

  17. Synergic interaction between ascorbic acid and antibiotics against Pseudomonas aeruginosa

    OpenAIRE

    Luciana Cursino; Edmar Chartone-Souza; Andréa Maria Amaral Nascimento

    2005-01-01

    Studies were carried out on in vitro combination of ascorbic acid (AA) with six antibiotics against 12 multi-resistant Pseudomonas aeruginosa isolates. Synergic activity was detected with AA chloramphenicol, kanamycin, streptomycin and tetracycline. Indifference was observed to any antibiotics and antagonism only for chloramphenicol. Results indicated that multiresistant P. aeruginosa was affected by combination of AA and antibiotics. Future research on ascorbic acid-antimicrobial interaction...

  18. L-Ascorbic Acid: A Multifunctional Molecule Supporting Plant Growth and Development

    OpenAIRE

    Gallie, Daniel R.

    2013-01-01

    L-Ascorbic acid (vitamin C) is as essential to plants as it is to animals. Ascorbic acid functions as a major redox buffer and as a cofactor for enzymes involved in regulating photosynthesis, hormone biosynthesis, and regenerating other antioxidants. Ascorbic acid regulates cell division and growth and is involved in signal transduction. In contrast to the single pathway responsible for ascorbic acid biosynthesis in animals, plants use multiple pathways to synthesize ascorbic acid, perhaps re...

  19. Ascorbic acid improves the antioxidant activity of European grape juices by improving the juices' ability to inhibit lipid peroxidation of human LDL in vitro

    DEFF Research Database (Denmark)

    Landbo, Anne-Katrine Regel; Meyer, Anne Boye Strunge

    2001-01-01

    Antioxidant activities of red and white European grape juices towards copper induced lipid oxidation of human low-density lipoproteins (LDL) were examined in vitro. LDL lipid peroxidation was assessed spectrophotometrically by monitoring the development of conjugated lipid hydroperoxides at 234 nm....... Red grape juice concentrate inhibited lipid peroxidation of LDL by prolonging the lag phase by 2.7 times relative to a control when evaluated at a total phenolic concentration of 10 muM gallic acid equivalents (GAE). Both red grape juices tested blocked lipid peroxidation of LDL at 20 muM GAE. White...... improved the antioxidant activities of red grape juices....

  20. PLASMID DNA DAMAGE CAUSED BY METHYLATED ARSENICALS, ASCORBIC ACID AND HUMAN LIVER FERRITIN

    Science.gov (United States)

    PLASMID DNA DAMAGE CAOUSED BY METHYLATED ARSENICALS, ASCORBIC ACID AND HUMAN LIVER FERRITINABSTRACT Both dimethylarsinic acid (DMA(V)) and dimethylarsinous acid (DMA(III)) release iron from human liver ferritin (HLF) with or without the presence of ascorbic acid. ...

  1. Sensitive Spectrophotometric Methods for the Determination of Ascorbic Acid

    OpenAIRE

    H. D. Revanasiddappa; M. A. Veena

    2008-01-01

    Two simple and sensitive spectrophotometric methods (A and B) have been described for the determination of ascorbic acid. Method A is based on the oxidation of ascorbic acid (AA) by known excess of Se(IV) in hydrochloric acid medium and subsequent determination of unreacted Se(IV) by reacting it with iodide in the same acid medium to liberate iodine, which react with starch to form a stable blue coloured iodine-starch complex, which shows maximum absorbance at 590 nm. Method B is based on the...

  2. Ascorbic acid: Chemistry, biology and the treatment of cancer?

    OpenAIRE

    Du, Juan; Cullen, Joseph J; BUETTNER, GARRY R.

    2012-01-01

    Since the discovery of vitamin C, the number of its known biological functions is continually expanding. Both the names ascorbic acid and vitamin C reflect its antiscorbutic properties due to its role in the synthesis of collagen in connective tissues. Ascorbate acts as an electron-donor keeping iron in the ferrous state thereby maintaining the full activity of collagen hydroxylases; parallel reactions with a variety of dioxygenases affect the expression of a wide array of genes, for example ...

  3. Anti-angiogenic effect of high doses of ascorbic acid

    Directory of Open Access Journals (Sweden)

    Ichim Thomas E

    2008-09-01

    Full Text Available Abstract Pharmaceutical doses of ascorbic acid (AA, vitamin C, or its salts have been reported to exert anticancer activity in vitro and in vivo. One proposed mechanism involves direct cytotoxicity mediated by accumulation of ascorbic acid radicals and hydrogen peroxide in the extracellular environment of tumor cells. However, therapeutic effects have been reported at concentrations insufficient to induce direct tumor cell death. We hypothesized that AA may exert anti-angiogenic effects. To test this, we expanded endothelial progenitor cells (EPCs from peripheral blood and assessed, whether or not high dose AA would inhibit EPC ability to migrate, change energy metabolism, and tube formation ability. We also evaluated the effects of high dose AA on angiogenic activities of HUVECs (human umbilical vein endothelial cells and HUAECs (human umbilical arterial endothelial cells. According to our data, concentrations of AA higher than 100 mg/dl suppressed capillary-like tube formation on Matrigel for all cells tested and the effect was more pronounced for progenitor cells in comparison with mature cells. Co-culture of differentiated endothelial cells with progenitor cells showed that there was incorporation of EPCs in vessels formed by HUVECs and HUAECs. Cell migration was assessed using an in vitro wound healing model. The results of these experiments showed an inverse correlation between AA concentrations relative to both cell migration and gap filling capacity. Suppression of NO (nitric oxide generation appeared to be one of the mechanisms by which AA mediated angiostatic effects. This study supports further investigation into non-cytotoxic antitumor activities of AA.

  4. Sequential injection redox or acid-base titration for determination of ascorbic acid or acetic acid.

    Science.gov (United States)

    Lenghor, Narong; Jakmunee, Jaroon; Vilen, Michael; Sara, Rolf; Christian, Gary D; Grudpan, Kate

    2002-12-01

    Two sequential injection titration systems with spectrophotometric detection have been developed. The first system for determination of ascorbic acid was based on redox reaction between ascorbic acid and permanganate in an acidic medium and lead to a decrease in color intensity of permanganate, monitored at 525 nm. A linear dependence of peak area obtained with ascorbic acid concentration up to 1200 mg l(-1) was achieved. The relative standard deviation for 11 replicate determinations of 400 mg l(-1) ascorbic acid was 2.9%. The second system, for acetic acid determination, was based on acid-base titration of acetic acid with sodium hydroxide using phenolphthalein as an indicator. The decrease in color intensity of the indicator was proportional to the acid content. A linear calibration graph in the range of 2-8% w v(-1) of acetic acid with a relative standard deviation of 4.8% (5.0% w v(-1) acetic acid, n=11) was obtained. Sample throughputs of 60 h(-1) were achieved for both systems. The systems were successfully applied for the assays of ascorbic acid in vitamin C tablets and acetic acid content in vinegars, respectively. PMID:18968850

  5. Study of Plasma Ascorbic Acid Levels in Wheezing Children

    Directory of Open Access Journals (Sweden)

    Nagdeote AN,

    2011-01-01

    Full Text Available Background: Reactive Oxygen species induced bronchial abnormalities may have important consequences in asthma, the main symptom being wheezing specially in children. Vitamin C is an important antioxidant known to quench the reactive oxygen species. A beneficial effect of fresh fruit consumption on lung function has been observed in several studies. Plasma levels Vitamin C was determined in relation to wheezing symptoms in cross sectional study. Methods: In a cross sectional blood samples of 50 patients attending pediatrics OPD, having wheezing and shortness of breath were analyzed for plasma Ascorbic acid level and compared with healthy controls of same age and sex. Results: The total number of 50 wheezing children were in the age group of 2 to 12 years with similar age matched controls. It was observed that the plasma ascorbic acid concentration in the wheezing children (0.43 – 0.12 mg/dl was significantly decreased as compared to the normal controls ( 0.75 – 0.18 mg/dl P< 0.001. The highly significant low levels of plasma ascorbic acid level in wheezing children was irrespective of sex and severity of symptoms. However the ascorbic acid levels were at the lower side in female and with severe symptoms. Conclusions: Plasma Ascorbic acid levels were significantly, decreased in the process of scavenging the reactive oxygen species. Ascorbic acid directly neutralizes free radical and protects the bronchial tissue from oxidative injury, so it can be concluded that the consumption of fruit rich in vitamin C may reduce wheezing symptoms in children.

  6. Simultaneous determination of uric acid and ascorbic acid using edge plane pyrolytic graphite electrodes

    OpenAIRE

    Kachoosangi, RT; Banks, CE; Compton, RG

    2006-01-01

    Edge plane pyrolytic graphite electrodes have been applied for the determination of uric acid and ascorbic acid. The separate determination of uric acid was found to produce three linear ranges from 100 nM to 3400 ?M with a detection limit of 30 nM found to be possible. Uric acid detection was also explored in the presence of 200 ?M ascorbic acid where a detection limit of 52 nM was found to be possible. The detection of ascorbic acid in the presence of uric acid was also explored over three ...

  7. Effect of ascorbic acid supplementation on nitric oxide metabolites and systolic blood pressure in rats exposed to lead

    Directory of Open Access Journals (Sweden)

    Mohammad Amani

    2010-01-01

    Full Text Available Background: Extended exposure to low levels of lead causes high blood pressure in human and laboratory animals. The mechanism is not completely recognized, but it is relatively implicated with generation of free radicals, oxidant agents such as ROS, and decrease of available nitric oxide (NO. In this study, we have demonstrated the effect of ascorbic acid as an antioxidant on nitric oxide metabolites and systolic blood pressure in rats exposed to low levels of lead. Materials and Methods: The adult male Wistar rats weighing 200-250 g were divided into four groups: control, lead acetate (receiving 100 ppm lead acetate in drinking water, lead acetate plus ascorbic acid (receiving 100 ppm lead acetate and 1 g/l ascorbic acid in drinking water, and ascorbic acid (receiving 1 g/l ascorbic acid in drinking water groups. The animals were anesthetized with ketamin/xylazine (50 and 7 mg/kg, respectively, ip and systolic blood pressure was then measured from the tail of the animals by a sphygmomanometer. Nitric oxide levels in serum were measured indirectly by evaluation of its stable metabolites (total nitrite and nitrate (NOc. Results: After 8 and 12 weeks, systolic blood pressure in the lead acetate group was significantly elevated compared to the control group. Ascorbic acid supplementation could prevent the systolic blood pressure rise in the lead acetate plus ascorbic acid group and there was no significant difference relative to the control group. The serum NOc levels in lead acetate group significantly decreased in relation to the control group, but this reduction was not significantly different between the lead acetate plus ascorbic acid group and the control group. Conclusion: Results of this study suggest that ascorbic acid as an antioxidant prevents the lead induced hypertension. This effect may be mediated by inhibition of NOc oxidation and thereby increasing availability of NO.

  8. Methylene Blue-Ascorbic Acid: An Undergraduate Experiment in Kinetics.

    Science.gov (United States)

    Snehalatha, K. C.; And Others

    1997-01-01

    Describes a laboratory exercise involving methylene blue and L-ascorbic acid in a simple clock reaction technique to illustrate the basic concepts of chemical kinetics. If stock solutions are supplied and each type of experiment takes no more than half an hour, the entire investigation can be completed in three practical sessions of three hours…

  9. Ascorbate and dehydroascorbic acid as reliable biomarkers of oxidative stress

    DEFF Research Database (Denmark)

    Lykkesfeldt, Jens

    2007-01-01

    Lack of post-sampling stability of ascorbate and dehydroascorbic acid and failure to block their in vivo equilibrium have lowered their value as biomarkers of oxidative stress and limited the ability to further investigate their possible role in disease prevention. In the present paper, the...

  10. SOURCE, CHEMISTRY, METABOLISM, PHYSIOLOGICAL FUNCTION: ASCORBIC ACID WITH HUMAN HEALTH

    Directory of Open Access Journals (Sweden)

    Prashansa Sharma

    2014-09-01

    Full Text Available Ascorbic acid commonly known as Vitamin C and it is water soluble vitamin having Antioxidant characteristics, abound in nature and highly labile.it is very important Vitamin for biosynthesis of collagen, carnitine and neurotransmitters. Some plants and animals synthesised this Vitamin but human, apes and some other are not able to synthesis this Vitamin due to lack of Gulonolactone oxidase enzyme. So, this Vitamin is supplemented by outer source like fruit, vegetable and synthetic pharmaceutical products. The current US recommended dietary allowances (RDA for Ascorbic acid is 100-120 mg/day. Ascorbic acid has many biochemical functions like Antioxidant, Anti-antherogenic, Anti-carcinogenic, immunodulator and its preventing cold. It’s also associated with reduction of incidence of cancer, immunity, blood pressure, drug metabolism and urinary hydroxyproline excretion, tissue regeneration. Mainly it shows effective result in gastric cancer. Ascorbic acid decreases the death risk. Now day, This Vitamin is used in nutraceutical in human biology and health.

  11. Old Things New View: Ascorbic Acid Protects the Brain in Neurodegenerative Disorders

    OpenAIRE

    Adriana Covarrubias-Pinto; Aníbal Ignacio Acuña; Felipe Andrés Beltrán; Leandro Torres-Díaz; Maite Aintzane Castro

    2015-01-01

    Ascorbic acid is a key antioxidant of the Central Nervous System (CNS). Under brain activity, ascorbic acid is released from glial reservoirs to the synaptic cleft, where it is taken up by neurons. In neurons, ascorbic acid scavenges reactive oxygen species (ROS) generated during synaptic activity and neuronal metabolism where it is then oxidized to dehydroascorbic acid and released into the extracellular space, where it can be recycled by astrocytes. Other intrinsic properties of ascorbic ac...

  12. Synergistic Chondroprotective Effect of ?-Tocopherol, Ascorbic Acid, and Selenium as well as Glucosamine and Chondroitin on Oxidant Induced Cell Death and Inhibition of Matrix Metalloproteinase-3—Studies in Cultured Chondrocytes

    Directory of Open Access Journals (Sweden)

    Anne-Christi Graeser

    2009-12-01

    Full Text Available Overproduction of reactive oxygen species and impaired antioxidant defence accompanied by chronic inflammatory processes may impair joint health. Pro-inflammatory cytokines such as interleukin-1? (IL-1? and tumor necrosis factor alpha (TNF-? stimulate the expression of metalloproteinases which degrade the extracellular matrix. Little is known regarding the potential synergistic effects of natural compounds such as ?-tocopherol (?-toc, ascorbic acid (AA and selenium (Se on oxidant induced cell death. Furthermore studies regarding the metalloproteinase-3 inhibitory activity of glucosamine sulfate (GS and chondroitin sulfate (CS are scarce. Therefore we have studied the effect of ?-toc (0.1–2.5 µmol/L, AA (10–50 µmol/L and Se (1–50 nmol/L on t-butyl hydroperoxide (t-BHP, 100–500 µmol/L-induced cell death in SW1353 chondrocytes. Furthermore we have determined the effect of GS and CS alone (100–500 µmol/L each and in combination on MMP3 mRNA levels and MMP3 secretion in IL-1? stimulated chondrocytes. A combination of ?-toc, AA, and Se was more potent in counteracting t-BHP-induced cytotoxicity as compared to the single compounds. Similarly a combination of CS and GS was more effective in inhibiting MMP3 gene expression and secretion than the single components. The inhibition of MMP3 secretion due to GS plus CS was accompanied by a decrease in TNF-? production. Combining natural compounds such as ?-toc, AA, and Se as well as GS and CS seems to be a promising strategy to combat oxidative stress and cytokine induced matrix degradation in chondrocytes.

  13. Synergistic Chondroprotective Effect of ?-Tocopherol, Ascorbic Acid, and Selenium as well as Glucosamine and Chondroitin on Oxidant Induced Cell Death and Inhibition of Matrix Metalloproteinase-3—Studies in Cultured Chondrocytes

    OpenAIRE

    Anne-Christi Graeser; Katri Giller; Heike Wiegand; Luca Barella; Christine Boesch Saadatmandi; Gerald Rimbach

    2009-01-01

    Overproduction of reactive oxygen species and impaired antioxidant defence accompanied by chronic inflammatory processes may impair joint health. Pro-inflammatory cytokines such as interleukin-1? (IL-1?) and tumor necrosis factor alpha (TNF-?) stimulate the expression of metalloproteinases which degrade the extracellular matrix. Little is known regarding the potential synergistic effects of natural compounds such as ?-tocopherol (?-toc), ascorbic acid (AA) and selenium (Se) on oxidant induced...

  14. Sonovoltammetric behavior of ascorbic acid and dehydroascorbic acid at glassy carbon electrodes: Analysis using pulsed sonovoltammetry

    OpenAIRE

    Richard G. Compton; Matysik, Frank-Michael

    1996-01-01

    The effect of power ultrasound on the voltammetric behavior of ascorbic acid and dehydroascorbic acid at a glassy carbon electrode is described. The voltammetric characteristics of both compounds were found to be modified by ultrasonically formed radicals. In the case of dehydroascorbic acid the single sweep voltammogram shows an anodic signal in the presence of ultrasound which probably results from the formation of an oxidizable radical known to be an intermediate of ascorbic acid oxidation...

  15. L-ascorbic acid- and L-ascorbic acid 2-glucoside accelerate in vivo liver regeneration and lower serum alanine aminotransaminase activity in 70% partially hepatectomized rats.

    Science.gov (United States)

    Kimura, Mitsutoshi; Moteki, Hajime; Uchida, Masaki; Natsume, Hideshi; Ogihara, Masahiko

    2014-01-01

    The effects of L-ascorbic acid and its stable analogue L-ascorbic acid 2-glucoside on the restoration of liver mass and recovery of liver function after 70% partial hepatectomy (PH), were compared with other natural vitamin C analogues in rats in vivo. L-Ascorbic acid (100 mg/kg/d, intraperitoneally (i.p.))- and L-ascorbic acid 2-glucoside (50 mg/kg/d, i.p.)-treated rats showed an approximately 1.3-fold increase in the ratio of liver weight (LW) to body weight (BW), when compared to saline (as control)-, L-dehydroascorbic acid (150 mg/kg/d, i.p.)- and D-isoascorbic acid (150 mg/kg/d, i.p.)-administrated rats on day 3 after PH. Accordingly, 5-bromo-2-deoxyuridine-labeling index in the regenerating liver was significantly higher in L-ascorbic acid- and L-ascorbic acid 2-glucoside-treated rats compared with saline-, L-dehydroascorbic acid and D-isoascorbic acid-treated rats on day 1. In control rats, liver-related serum alanine aminotransferase (ALT) activity was rapidly elevated on day 1, and then decreased to near pre-operative levels on day 5 following PH. L-Ascorbic acid and L-ascorbic acid 2-glucoside significantly lowered the serum ALT on day 1 after PH compared with saline-, L-dehydroascorbic acid- and D-isoascorbic acid-administered rats. These results demonstrate that L-ascorbic acid and L-ascorbic acid 2-glucoside significantly promote the regeneration of liver mass and function with full recovery after liver injury. PMID:24818255

  16. Precipitation behaviors of palladium, rhodium and rhenium with ascorbic acid

    International Nuclear Information System (INIS)

    Recovery of platinum group metals and transition element such as palladium, rhodium, ruthenium and technetium in SNF are becoming important issues around the world, due to their economic values of noble metals and also radio toxicity of technetium. Precipitation is reportedly one of the possible methods to recover platinum group metals. Especially, an ascorbic acid is reviewed as a promising precipitant for palladium recovery. Also some successful results were reported with relation to the selective precipitation of palladium ion in the simulated fission product solution. However, since most of them are qualitative results with limited data and considering that the purity of noble metal is crucial for its value, quantitative data depending on the various experimental variables are also required. In this study, precipitation behaviors for palladium by ascorbic acid were investigated to obtain the qualitative precipitation data depending on the coexisting ions and other operation variables

  17. Ineffectiveness of ascorbic acid therapy in nephropathic cystinosis.

    Science.gov (United States)

    Schneider, J A; Schlesselman, J J; Mendoza, S A; Orloff, S; Thoene, J G; Kroll, W A; Godfrey, A D; Schulman, J D

    1979-04-01

    Because high concentrations of ascorbic acid (0.57 mM) lower the free (nonprotein) cystine content of cultured cystinotic skin fibroblasts by over 50 per cent, we did a double-blind clinical trial to establish whether this drug would benefit cystinotic children. Sixty-four patients were randomized into the study; 32 received ascorbic acid (200 mg per kilogram of body weight per day), and 32 placebo. The study was terminated after approximately two years because there was no indication that vitamin C was beneficial and accumulating evidence that it might be harmful. Of 11 patients who left the study because of death or the requirement for dialysis or renal transplantation, eight were receiving ascorbic acid. The estimated relative risk (treatment vs. control) of an adverse event was R = 2.7, with a 90 per cent confidence interval of (0.8, 11.5). The serum creatinine concentration increased 0.53 mg per deciliter per year in patients receiving vitamin C and 0.24 mg per deciliter per year in patients receiving placebo (P = 0.08). PMID:370586

  18. Production of ascorbic acid releasing biomaterials for pelvic floor repair

    Science.gov (United States)

    Mang?r, Na?ide; Bullock, Anthony J.; Roman, Sabiniano; Osman, Nadir; Chapple, Christopher; MacNeil, Sheila

    2016-01-01

    Objective An underlying abnormality in collagen turnover is implied in the occurrence of complications and recurrences after mesh augmented pelvic floor repair surgeries. Ascorbic acid is a potent stimulant of collagen synthesis. The aim of this study is to produce ascorbic acid releasing poly-lactic acid (PLA) scaffolds and evaluate them for their effects on extracellular matrix production and the strength of the materials. Materials and methods Scaffolds which contained either l-ascorbic acid (AA) and Ascorbate-2-Phosphate (A2P) were produced with emulsion electrospinning. The release of both drugs was measured by UV spectrophotometry. Human dermal fibroblasts were seeded on scaffolds and cultured for 2 weeks. Cell attachment, viability and total collagen production were evaluated as well as mechanical properties. Results No significant differences were observed between AA, A2P, Vehicle and PLA scaffolds in terms of fibre diameter and pore size. The encapsulation efficiency and successful release of both AA and A2P were demonstrated. Both AA and A2P containing scaffolds were significantly more hydrophilic and stronger in both dry and wet states compared to PLA scaffolds. Fibroblasts produced more collagen on scaffolds containing either AA or A2P compared to cells grown on control scaffolds. Conclusion This study is the first to directly compare the two ascorbic acid derivatives in a tissue engineered scaffold and shows that both AA and A2P releasing electrospun PLA scaffolds increased collagen production of fibroblasts to similar extents but AA scaffolds seemed to be more hydrophilic and stronger compared to A2P scaffolds. Statement of significance Mesh augmented surgical repair of the pelvic floor currently relies on non-degradable materials which results in severe complications in some patients. There is an unmet and urgent need for better pelvic floor repair materials. Our current understanding suggests that the ideal material should be able to better integrate into sites of implantation both biologically and mechanically. The impact of vitamin C on extracellular matrix production is well established but we in this study have undertaken a critical comparison of two derivatives of vitamin C as they are released from a biodegradable scaffold. This strategy proved to be equally useful with both derivatives in terms of new tissue production yet we observed significant differences in mechanical properties of these biomaterials. PMID:26478470

  19. Effect of Rosemary, Echinacea, Green Tea Extracts and Ascorbic Acid on Broiler Meat Quality

    Directory of Open Access Journals (Sweden)

    R. Mirshekar

    2009-01-01

    Full Text Available This study evaluated the effect of addition some plant extracts and ascorbic acid in presence of distilled water as the control on the broiler thigh meat color, subsequent lipid oxidation (TBARS and rancidity development during frozen storage of chicken thigh meat. All the extracts were used in the density of 1000 ppm. The results showed that all the antioxidants had significant effect on lipid oxidation as measured by TBARS value during frozen storage at -20°C for 120 days. However, lipid oxidation only occurred to a limited extent and was insufficient to cause rancid flavor development. The results also demonstrated that rosemary and green tea were the most effective antioxidants in stabilization of a* value. Echinacea, green tea and rosemary extracts were effective antioxidants and strongly inhibited oxidation. Present findings show that these plants extracts exhibit greater antioxidant efficiency compared to ascorbic acid.

  20. Suppression of radiation-induced in vitro carcinogenesis by ascorbic acid

    International Nuclear Information System (INIS)

    The effects of ascorbic acid on radiation-induced in vitro carcinogenesis have been reported using neoplastic transformation system of C3H 10T1/2 cells. In these reports, no suppressive effect on X-ray-induced transformation was observed with 6 weeks' administration of ascorbic acid (daily addition for 5 days per week) by Kennedy (1984), whereas apparent suppression was observed with daily addition for 7 days by Yasukawa et al (1989). We have tested the effects of ascorbic acid on 60Co gamma-ray or 252Cf fission neutron-induced transformation in Balb/c 3T3 cells. The transformation induced by both types of radiations was markedly suppressed when ascorbic acid was daily added to the medium during first 8 days of the post-irradiation period. If ascorbic acid was added for a total of 8 days but with a day's interruption in the middle, the suppression of transformation was decreased. These results suggest that continuous presence of ascorbic acid for a certain number of days is needed to suppress radiation-induced transformation. Since ascorbic acid also suppressed the promotion of radiation-induced transformation by TPA when both chemicals were added together into the medium, ascorbic acid might act on the promotion stage of transformation. Therefore, the effect of ascorbic acid on the distribution of protein kinase C activity was also investigated, and possible mechanisms of suppression of radiation-induced transformation by ascorbic acid will be discussed. (author)

  1. Uptake of ascorbic acid by freshly isolated cells and secretory granules from the intermediate lobe of ox hypophyses

    DEFF Research Database (Denmark)

    Zhou, A; Matsumoto, T

    1990-01-01

    Mechanically isolated cells from the intermediate lobe of ox hypophyses contained 40.6 +/- 3.7 nmol mg-1 protein (mean +/- SE, n = 5) of ascorbic acid. They accumulated radioactivity time dependently, on incubation with L-[14C]ascorbic acid in ionic medium dominated by NaCl. No definite saturation of uptake occurred when mechanically isolated cells were incubated with increasing ascorbic acid concentrations up to 0.6 mM. But if such cells were purified on a Percoll gradient, a clear saturation of uptake could be observed. Acetylsalicylic acid reduced the uptake markedly. When cells loaded with L-[14C]ascorbic acid were homogenized and placed on a Percoll gradient, the radioactivity was recovered in several subcellular fractions. Decrease of the Na+ concentration or presence of ouabain in the medium did not cause noticeable changes in uptake by non-purified cells, whereas uptake by purified cells was clearly sodium-dependent. Phloridzin inhibited uptake. Secretory granules from pars intermedia contained 40.0 +/- 3.8 nmol mg-1 protein of ascorbic acid (mean +/- SE, n = 3) and could accumulate L-[14C]ascorbic acid rapidly in a KCl-dominated medium. The uptake was not saturable with ascorbic acid concentration and was not influenced by the presence of I mM ATP + I mM Mg2+ in the medium. The concentration of copper and iron in isolated cells was comparable to that in isolated neurohypophysial nerve terminals, whereas the concentration of zinc was considerably higher in the pars intermedia cells. The concentration of Cu, Zn, Fe and Co in secretory granules from pars intermedia was higher than in secretory granules from neurohypophyses.

  2. Redox cycling of polycyclic aromatic hydrocarbon o-quinones: reversal of superoxide dismutase inhibition by ascorbate.

    Science.gov (United States)

    Jarabak, R; Harvey, R G; Jarabak, J

    1997-03-01

    When redox cycling of four polycyclic aromatic hydrocarbon o-quinones is catalyzed by the 17 beta-hydroxysteroid dehydrogenase, autooxidation of the hydroquinone is a free radical chain reaction in which superoxide anion is the propagating species. Superoxide dismutase inhibits the redox cycling of these quinones, and ascorbate reverses this inhibition. Studies of the mechanism, using 9,10-phenanthrenequinone, show that ascorbate competes with superoxide dismutase for the superoxide anion; the ascorbyl radical formed then oxidizes the hydroquinone. In this mechanism, ascorbyl radical participates in chain propagation. The reversal of superoxide dismutase inhibition by ascorbate is observed when other two-electron reductases catalyze the cycling, and it occurs in the absence of metal ions. Although ascorbate is generally thought to be an antioxidant, it behaves as a prooxidant in the experiments reported here. PMID:9056238

  3. The ascorbic acid content in monkeys subjected to low-dose prolonged irradiation

    International Nuclear Information System (INIS)

    The level of ascorbic acid has been studied in monkeys subjected to prolonged low-dose irradiation. In addition to changes in the clinical picture (ulcerous gingivitis, hypochromic anemia, petechia, impaired immunogenesis, etc.), a decrease in the ascorbic acid content in blood has been observed. The prolonged irradiation with low doses has been found to cause stable disorders in the ascorbic acid metabolism which are observed in monkeys survived after irradiation (two years later)

  4. [Ascorbic Acid and Charcot-Marie-Tooth Disease].

    Science.gov (United States)

    Noto, Yu-ichi

    2015-10-01

    Charcot-Marie-Tooth disease type 1A (CMT1A) is a disease for which no drug treatments are available. Passage et al. reported that ascorbic acid reduced the mRNA level of PMP22, improved motor function and increased the numbers of myelinated peripheral nerve axons in a mouse model of CMT1A. Based on these results, five clinical trials were undertaken at different centers worldwide. However, none of them demonstrated significant effectiveness. Although these outcomes were disappointing, these studies have provided many useful insights for conducting the next randomised controlled trial for CMT1A. PMID:26450076

  5. Effects of supplemental ascorbic acid on humeral immune response in broilers reared under heat-stress condition

    Directory of Open Access Journals (Sweden)

    Vahel J. A. Amedy,

    2011-07-01

    Full Text Available An experiment was conducted to evaluate the efficacy of supplemental ascorbic acid (Vitamin C on the haemagglutination inhibition (HI and enzyme linked immune sorbent assay (ELISA antibody titer of the commercial broiler chicks vaccinated against Newcastle disease (ND virus, reared under heat stress condition. A total of 420, one day-old broiler chicks were randomly divided into 4 groups and kept under elevated summer temperature and treated with four levels of added ascorbic acid i.e., 0 (control group, 200, 400, 600 mg/kg in diets for 28 days, from 21 to 49 days of experimental period. HI antibody titer and ELISA antibody titer against ND virus were significantly (P<0.05 higher at 600 mg/kg Vitamin C in the diet than the others treatments. Apparently, adding ascorbic acid at 600 mg/kg in the diet could improve humoral immunity in broilers reared under heat stress.

  6. The novel Arabidopsis thaliana svt2 suppressor of the ascorbic acid-deficient mutant vtc1-1 exhibits phenotypic and genotypic instability [v1; ref status: indexed, http://f1000r.es/o2

    OpenAIRE

    Kempinski, Chase F; Crowell, Samuel V; Caleb Smeeth; Carina Barth

    2013-01-01

    Ascorbic acid is a potent antioxidant that detoxifies reactive oxygen species when plants are exposed to unfavorable environmental conditions. In addition to its antioxidant properties, ascorbic acid and its biosynthetic precursors fulfill a variety of other physiological and molecular functions. A mutation in the ascorbic acid biosynthesis gene VTC1, which encodes GDP-mannose pyrophosphorylase, results in conditional root growth inhibition in the presence of ammonium. To isolate suppresso...

  7. Ascorbic acid glucoside reduces neurotoxicity and glutathione depletion in mouse brain induced by nitrotriazole radiosensitazer

    Directory of Open Access Journals (Sweden)

    Nadezda V Cherdyntseva

    2013-01-01

    Full Text Available Aim: To investigate the potential of the anti-oxidant ascorbic acid glucoside (AA-2G to modulate neurotoxicity induced by high doses of nitrotriazole radiosensitizer. Materials and Methods: Male and female C56Bl/6xCBA hybrid mice aged 8-14 weeks (weight 18-24 g were used. Nitrotriazole drug radiosensitizer sanazole at a high dose of 2, 1 g/kg was per os administered to induce neurotoxicity at mice. Ascorbic acid glucoside was given 30 min before the sanazole administration. Serum ascorbic acid, brain glutathione level, as well as behavioral performance using open field apparatus were measured. Results: Administration of high (non-therapeutic doses of the nitrotriazole drug sanazole results in neurotoxicity in mice as evidenced from behavioral performance, emotional activity and depletion of the cellular antioxidant, glutathione, in the brain. The serum levels of ascorbic acid was also found reduced in high dose sanazole treated animals. Per os administration of ascorbic acid glucoside significantly reduced the neurotoxicity. This effect was associated with the prevention of glutathione depletion in mouse brain and restoring the ascorbic acid level in serum. Conclusion: Administration of ascorbic acid glucoside, but not ascorbic acid, before sanazole administration protected from sanazole-induced neurotoxicity by preventing the decrease in the brain reduced glutathione level and providing high level of ascorbic acid in plasma.

  8. Measurement of binding of ascorbic acid to myrosinase by rate of dialysis

    International Nuclear Information System (INIS)

    The activation mechanism of myrosinase by L-ascorbic acid depends on the slight conformational change of enzyme protein induced by ascorbic acid. Ascorbic acid binds to enzyme like Michaelis-complex, and then the value of Km had been evaluated to be 1 x 10-3M. The authors determined the binding constant and the number of binding sites using dialysis rate technique. Rate dialysis was carried out with a dialysis cell, and the ordinary cellophane tubing membrane was used. (14C)- ascorbic acid was added, and counted by liquid scintillation counting. By the time course of two dialysis rate measurement with and without enzyme. The concentrations of free and bound ascorbic acids were counted. From the results, the enzyme was activated to the maximum level at 10-3M of ascorbic acid, and four molecules of ascorbic acid bound to the enzyme on Kd=0.1x10-4M. However, when more than 4 molecules of L-ascorbic acid bound to the enzyme, Kd increased to 0.9x10-4M, and L-ascorbic acid acted as an inhibitor. (Kubatake, H.)

  9. Neutron scattering and HPLC study on L-ascorbic acid and its degradation

    Energy Technology Data Exchange (ETDEWEB)

    Bellocco, E. [Department of Organic and Biological Chemistry, University of Messina, Messina (Italy)], E-mail: bellocco@isengard.unime.it; Barreca, D.; Lagana, G.; Leuzzi, U. [Department of Organic and Biological Chemistry, University of Messina, Messina (Italy); Migliardo, F.; Torre, R. La; Galli, G. [Department of Physics, University of Messina, Messina (Italy); Galtieri, A. [Department of Organic and Biological Chemistry, University of Messina, Messina (Italy); Minutoli, L.; Squadrito, F. [Department of Clinical and Experimental Medicine and Pharmacology, University of Messina, Messina (Italy)

    2008-04-18

    The present paper shows a systematic dynamic and kinetic study on L-ascorbic acid and its degradation at high temperature. The neutron scattering study allows, through the behavior of quasi-elastic neutron scattering (QENS) spectra, to characterize the diffusive dynamics of L-ascorbic acid in water mixtures. Ascorbic acid undergoes degradation process at high temperature, but the presence of trehalose in solution markedly avoids ascorbic acid loss enhancing its t{sub 1/2} (half life time), as determined by high performance liquid chromatography (HPLC)

  10. Anti-transforming nature of ascorbic acid and its derivatives examined by two-stage cell transformation using BALB/c 3T3 cells.

    Science.gov (United States)

    Tsuchiya, T; Kato-Masatsuji, E; Tsuzuki, T; Umeda, M

    2000-11-10

    The anti-transforming effects of sodium ascorbate and its stable derivatives were examined in the two-stage transformation assay. When BALB/c 3T3 cells were treated with 0.2 microg/ml 20-methylcholanthrene as an initiator, and 100 ng/ml 12-O-tetradecanoylphorbol-13-acetate as a promoter, the addition at the promotion stage of L-ascorbic acid-2-phosphate ester magnesium (APM) was most marked in the inhibition of transformation. The inhibitory effects of sodium ascorbate and ascorbic acid-2-glucoside (AG) were comparable, but weaker than those of APM; L (+)-ascorbic acid-2-sulfate ester disodium 2H(2)O showed little effect. When phorbol 12, 13-didecanoate or tumor necrosis factor alpha (TNF-alpha) were used as promoters, APM also effectively suppressed transformation. PMID:11098084

  11. Importance of ascorbic acid in the absorption of iron from infant foods

    International Nuclear Information System (INIS)

    The absorption of fortification iron from an infant milk formula and from 3 infant cereals was studied in 121 multiparous women. The mean absorption was less than 3.2% when no added ascorbic acid was present. The nature of the iron compound added to infant cereals did not seem to influence the amount absorbed. Absorption was significantly improved when ascorbic acid was added, the mean increase being threefold with an iron:ascorbic ratio of 1:1.5 molar and more than sixfold with a ratio of 1:3 molar (about 10 mg ascorbic acid per mg iron). (author)

  12. Efficiency of ascorbic acid and ?-rays to ameliorate the quality of ready-to-eat baked bolti fish fillets

    International Nuclear Information System (INIS)

    Ascorbic acid (vitamin C) is a reducing agent, inhibits oxidative reactions developed in cold-storage Bolti (Tilapia nilotica) fish. It is the most popular fish repasts in Egypt. To determine the influence of ascorbic acid on cooking (roasting) and irradiated fish fillets to extend their storage-time in refrigerators, 3 patches of fish fillets were prepared; control (0 kGy), ascorbic acid plus 2.5 kGy and ascorbic acid plus 4 kGy and were tested for bacteriological examination, chemical analysis and sensory evaluation at 0, 1, 2 and 3 weeks of cold storage at 5±1 degree C. The bacteriological examinations were total aerobic plate counts, psychotropic bacterial counts, Enterobacteriaceae counts, total mould and yeast counts and microbial pathogens counts (Salmonella and Vibrio species). The chemical analyses were thiobarbituric acid reactive substances (TBARS), inosine 5-monophosphate (IMP) concentration, hypoxanthine (HX) concentration, ph figure, total volatile nitrogen (TVN) and total trimethylamine nitrogen (TMA-N). The sensory evaluation was (texture and odour factors) of the cold-storage Bolti fish fillets samples. The results revealed that aerobically packed fish fillets samples treated with ascorbic acid plus 4 kGy after cooking had satisfied bacteriological, chemical and organoleptical trails. Conclusion: using of baking, irradiation combined with natural antioxidant nd refrigeration could reduce the energy requirements for freezing and costs for the marketing of ready- to-eat fish repasts. Recommendation: combination effects of ?-irradiation plus ascorbic acid in processing fish fillets help to preserve its quality. The possible strategies for improving fish fillets quality and acceptability are discussed

  13. Improvement of bioavailability for iron from vegetarian meals by ascorbic acid

    International Nuclear Information System (INIS)

    There are two kinds of iron in the diet with respect to the mechanism of absorption, heme-iron which is present as haemoglobin or myoglobin in meat and blood products, and, non-heme iron which is the main source of dietary iron. The bioavailability of the non-heme food iron is much lower than heme-iron. Vegetarian diets contain only non-heme iron. Iron intake from vegetarian meals are generally satisfied with the requirements, however, the bioavailabilities for non-heme iron is determined not only by iron content byt also the balance between different dietary factors enhancing and inhibiting iron absorption. The main enhancing factor in vegetarian meals is ascorbic acid in fruits and vegetables, inhibitors are phytate in cereals and grains, and tannins in some spices and vegetables. It has been reported that iron deficiency is one of the common micronutrient problems associated with unplanned vegetarian diets. In the present study the absorption of non-heme iron was measured from 2 vegetarian meals containing considerable amounts of phytate and tannin. The extrinsic tay method (59Fe/ 55Fe) was used to labelled the non-heme iron. The mean percentage absorption of non-heme iron from both meals was slightly different due to differences in their dietary contents. Their initial percentages iron absorption were apparent low (3.5% and 4.1%), however, the absorption progressively increased with increase in the level of ascorbic acid, 2-3 times with 100 mg and 4-5 times with 200 mg of ascorbic acid. The average amount of iron absorbed per 2000 kcal increased from 0.37 mg to 0.86 mg and 1.45 mg with the addition of 100 mg and 200 mg ascorbic acid respectively (p < 0.001). Considering the limited caloric intakes and the iron content in the meals, the amount of iron absorbed from vegetarian meals without ascorbic acid was not able to meet certain requirements for children, adolescents and menstruating women. The minimal requirement for dietary iron needed to be absorbed is 0.49 mg for 50% of 1-2 year children and more than 1 mg for girls and menstruating women. The vegetarian meals as compared with ordinary mixed meals can provided most of the nutrients in the amounts close to or above the recommended intaked according to the Recommended Daily Allowances (RDA). However, the amounts of iron absorbed from these meals are quite precarious and fail to meet the requirements for the important target groups. It is suggested that, vegetarian diets can assure nutrient adequacy and promote health when they are planned and chosen in the line with scientific nutrition principles

  14. Retention of ascorbic acid in fortified orange juice powers during storage

    Directory of Open Access Journals (Sweden)

    G. S. Siddappa

    1960-10-01

    Full Text Available Both Coorg and Sathgudi orange juice powders are good carriers for added ascorbic acid during prolonged storage at ordinary temperatures. There is not much difference between nitrogen and air packs as regards retention of ascorbic acid during storage. Nitrogen pack, however, helps to keep the power in a better free-flowing condition.

  15. Plant resistance mechanisms to air pollutants: rhythms in ascorbic acid production during growth under ozone stress

    Energy Technology Data Exchange (ETDEWEB)

    Lee, E.H. (Climate Stress Laboratory, USDA, ARS, Beltsville, MD (United States))

    1991-01-01

    Relationships between ozone (O3) tolerance and leaf ascorbic acid concentrations in O3-susceptible (O3-S) 'Hark' and O3-resistant (O3-R) 'Hood' soybean, Glycine max (L.) Merr., cultivars were examined with high-performance liquid chromatography (HPLC). Leaf samples were analyzed at 4 intervals during a 24 h period. Soybean cultivars grown in the greenhouse with charcoal filtered (CF) and nonfiltered (NF) air showed daily oscillations in ascorbic acid production. Highest ascorbic acid levels in leaves during light coincided with highest concentrations of photochemical oxidants in the atmosphere at 2:00 p.m. The resistant genotype produced more ascorbic acid in its trifoliate leaves than did the corresponding susceptible genotype. Under CF air (an O3-reduced environment) O3-S and O3-R cultivars showed rhythms in ascorbic acid production. In NF air (an O3 stress environment) the O3-R cultivar alone showed rhythms in ascorbic acid production. Results indicated that superior O3 tolerance in the Hood soybean cultivar (compared with Hark) was associated with a greater increase in endogenous levels of ascorbic acid. Ascorbic acid may scavenge free radicals and thereby protect cells from injury by O3 or other oxyradical products. Plants defend themselves against photochemical oxidant stress, such as O3, by several mechanisms. Experimental evidence indicates that antioxidant defense systems existing in plant tissues may function to protect cellular components from deleterious effects of photochemical oxidants through endogenous and exogenous controls.

  16. Glycation by ascorbic acid oxidation products leads to the aggregation of lens proteins.

    Science.gov (United States)

    Linetsky, Mikhail; Shipova, Ekaterina; Cheng, Rongzhu; Ortwerth, Beryl J

    2008-01-01

    Previous studies from this laboratory have shown that there are striking similarities between the yellow chromophores, fluorophores and modified amino acids released by proteolytic digestion from calf lens proteins ascorbylated in vitro and their counterparts isolated from aged and cataractous lens proteins. The studies reported in this communication were conducted to further investigate whether ascorbic acid-mediated modification of lens proteins could lead to the formation of lens protein aggregates capable of scattering visible light, similar to the high molecular aggregates found in aged human lenses. Ascorbic acid, but not glucose, fructose, ribose or erythrulose, caused the aggregation of calf lens proteins to proteins ranging from 2.2 x 10(6) up to 3.0 x 10(8 )Da. This compared to proteins ranging from 1.8 x 10(6) up to 3.6 x 10(8 )Da for the water-soluble (WS) proteins isolated from aged human lenses. This aggregation was likely due to the glycation of lens crystallins because [U-(14)C] ascorbate was incorporated into the aggregate fraction and because NaCNBH(3), which reduces the initial Schiff base, prevented any protein aggregation. Reactions of ascorbate with purified crystallin fractions showed little or no aggregation of alpha-crystallin, significant aggregation of beta(H)-crystallin, but rapid precipitation of purified beta(L)- and gamma-crystallin. The aggregation of lens proteins can be prevented by the binding of damaged crystallins to alpha-crystallin due to its chaperone activity. Depending upon the ratios between the components of the incubation mixtures, alpha-crystallin prevented the precipitation of the purified beta(L)- and gamma-crystallin fractions during ascorbylation. The addition of at least 20% of alpha-crystallin by weight into glycation mixtures with beta(L)-, or gamma-crystallins completely inhibited protein precipitation, and increased the amount of the high molecular weight aggregates in solution. Static and dynamic light scattering measurements of the supernatants from the ascorbic acid-modified mixtures of alpha- and beta(L)-, or gamma-crystallins showed similar molar masses (up to 10(8 )Da) and hydrodynamic diameter (up to 80( )nm). These data support the hypothesis, that if the lens reducing environment is compromised, the ascorbylation of lens crystallins can significantly change the short range interactions between different classes of crystallins leading to protein aggregation, light scattering and eventually to senile cataract formation. PMID:18023423

  17. A flexible micro biofuel cell utilizing hydrogel containing ascorbic acid

    International Nuclear Information System (INIS)

    This paper reports on a biofuel cell with a dimension of 13×24 mm2 fabricated on a flexible polyimide substrate. I its porous carbon-coated platinum (Pt) electrodes of 3 mm in width and 10 mm in length were fabricated using photolithography and screen printing techniques. Porous carbon was deposited by screen printing of carbon black ink on the Pt electrode surfaces in order to increase the effective electrode surface area and to absorb more enzymes on the electrode surfaces. It utilizes a solidified ascorbic acid (AA) aqueous solution in an agarose hydrogel to increase the portability. The maximum power and power density for the biofuel cell with the fuel unit containing 100 mM AA were 0.063 ?W and 0.21 ?W/cm2 at 0.019 V, respectively

  18. A flexible micro biofuel cell utilizing hydrogel containing ascorbic acid

    Science.gov (United States)

    Goto, Hideaki; Fukushi, Yudai; Nishioka, Yasushiro

    2014-11-01

    This paper reports on a biofuel cell with a dimension of 13×24 mm2 fabricated on a flexible polyimide substrate. I its porous carbon-coated platinum (Pt) electrodes of 3 mm in width and 10 mm in length were fabricated using photolithography and screen printing techniques. Porous carbon was deposited by screen printing of carbon black ink on the Pt electrode surfaces in order to increase the effective electrode surface area and to absorb more enzymes on the electrode surfaces. It utilizes a solidified ascorbic acid (AA) aqueous solution in an agarose hydrogel to increase the portability. The maximum power and power density for the biofuel cell with the fuel unit containing 100 mM AA were 0.063 ?W and 0.21 ?W/cm2 at 0.019 V, respectively.

  19. Amperometric biosensor for ascorbic acid / Biossensor amperométrico para ácido ascórbico

    Scientific Electronic Library Online (English)

    I. N., Tomita; A., Manzoli; F. L., Fertonani; H., Yamanaka.

    Full Text Available Desenvolveu-se um biossensor para ácido L-ascórbico empregando ascorbato oxidase. A enzima foi extraída do mesocarpo de pepino com solução tampão fosfato 0,05 mol L-1, pH 5,8 contendo NaCl 0,5 mol L-1. Após diálise versus solução tampão fosfato 0,05 mol L-1, pH 5,8 a enzima foi imobilizada em rede d [...] e nylon através de ligação covalente com glutaraldeído. A membrana foi acoplada em eletrodo de O2 e a reação monitorada pelo consumo de oxigênio a -600 mV em análise em fluxo (solução tampão fosfato 0,05 mol L-1, pH 5,8 como carregador e vazão 0,5 mL min-1). A curva analítica apresentou-se linear entre 1,2x10-4 a 1,0x10-3 mol L-1. O tempo de vida do biossensor foi de 500 análises. Amostras de medicamentos foram analisadas com a metodologia proposta e os resultados comparados com os obtidos com HPLC. Abstract in english A L-ascorbic acid biosensor based on ascorbate oxidase has been developed. The enzyme was extracted from the mesocarp of cucumber (Cucumis sativus) by using 0.05 mol L-1 phosphate buffer, pH 5.8 containing 0.5 mol L-1 NaCl. After the dialysis versus phosphate buffer 0.05 mol L-1 pH 5.8, the enzyme w [...] as immobilized onto nylon net through glutaraldehyde covalent bond. The membrane was coupled to an O2 electrode and the yielding reaction monitored by oxygen depletion at -600 mV using flow injection analysis optimized to 0.1 mol L-1 phosphate buffer pH 5.8, as the carrier solution and flow-rate of 0.5 mL min-1. The ascorbic acid calibration curve was linear from 1.2x10-4 to 1.0x10-3 mol L-1. The evaluation of biosensor lifetime leads to 500 injections. Commercial pharmaceutical samples were analyzed with the proposed method and the results were compared with those obtained by high-performance liquid chromatography (HPLC).

  20. Enhancement by ascorbic acid 2-glucoside or repeated additions of ascorbate of mitogen-induced IgM and IgG productions by human peripheral blood lymphocytes.

    Science.gov (United States)

    Tanaka, M; Muto, N; Gohda, E; Yamamoto, I

    1994-12-01

    In this study, the effect of ascorbic acid 2-glucoside (AA-2G), a stable derivative of ascorbic acid (AsA), or repeated additions of ascorbate on antibody productions by human peripheral blood lymphocytes (PBLs) was examined, and the physiological function of AsA was evaluated. When human PBLs were stimulated with Staphylococcus aureus Cowan I or pokeweed mitogen, AA-2G remarkably increased the numbers of IgM- and IgG-secreting cells which were detected by enzyme-linked immunospot assay. Although a single addition of ascorbate was without effect, the effect of AA-2G was remarkably inhibited by the addition of castanospermine, an alpha-glucosidase inhibitor; and moreover, repeated additions of AsA to the culture medium during the culture period enhanced the response to the same level as did a single addition of AA-2G. These results indicate that AsA has the ability to stimulate the immunoglobulin productions by AA-2G. The phytohemagglutinin-induced proliferative response of PBLs was also stimulated by AA-2G. The intracellular AsA content in PBLs cultured with AA-2G was maintained at relatively high levels during the culture period, whereas the content with a single dose of AsA reached nearly zero by the end of the experiment. These in vitro findings suggest that AA-2G and AsA function as potent immunostimulators of antibody production in humans and that the intracellular AsA content is a key parameter for establishing the immune response of PBLs. PMID:7723222

  1. CITOGENETICS EFFECTS INDUCED BY THE ASCORBIC ACID TREATMENT OF LARIX DECIDUA MILL. SSP. CARPATICA AND PICEA ABIES (L. KARST

    Directory of Open Access Journals (Sweden)

    Ioana Ieremia

    2006-08-01

    Full Text Available The paper present the influence of ascorbic acid upon the mitotic division of Larix decidua Mill ssp. carpatica and Picea abies (L. Karst. The treatment is applied of two variants, germinated seed in ascorbic acid (variantAand germinated seeds in disttilate water, than treated with ascorbic acid in 3 concentrations (variant B.

  2. Ascorbate enhances u.v.-mutagenesis in E. coli but inhibits it in Chinese hamster cells

    International Nuclear Information System (INIS)

    Ascorbic acid (vitamin C) causes an increase in the mutation frequency of u.v.-irradiated Escherichia coli WP2. The enhancement occurs at all u.v. fluences, and is dependent upon the ascorbate concentration in the medium. A maximum effect (approximately 8- to 13-fold) is seen at 100-150 micrograms/ml, although some enhancement can be seen even at 10 micrograms/ml. The comutagenic effect of ascorbate with u.v. in E. coli is dependent upon peptone, a constituent of nutrient broth. The enhancement of u.v.-mutagenesis by ascorbate is absent in strains WP2s (uvrA) and WP6 (polA), suggesting that ascorbate affects the repair of pyrimidine dimers. The opposite results are observed for u.v.-mutagenesis in Chinese hamster V79 cells. The presence of ascorbate (50 micrograms/ml) during u.v. irradiation does not enhance the u.v. effect, but rather decreases it approximately 30%. These results are discussed with regard to differences in the mechanism of u.v.-mutagenesis and DNA repair in bacterial and mammalian cells

  3. Electrochemical examination of the ascorbic acid radical anion in non-aqueous electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Yoshimura, M.; Honda, K.; Kondo, T.; Rao, T.N.; Tryk, D.A.; Fujishima, A

    2002-10-15

    A quasi-reversible redox reaction involving ascorbic acid was observed in non-aqueous electrolytes at conductive diamond electrode. The chemical reversibility of these reactions is consistent with ascorbic acid being reduced to the ascorbic acid radical anion in a one-electron process, with subsequent reoxidation to ascorbic acid. This is the first report on the electrochemical production of the ascorbic acid radical anion in non-aqueous electrolytes. Ascorbyl 6-stearate and 4-hydroxy 2(5H)-furanone, which have somewhat similar structures as ascorbic acid, also showed one-electron transfer reduction reaction producing radicals with a single negative charge, suggesting that these compounds follow the same electrochemical behavior as ascorbic acid. The double bond and hydroxyl substituent on the five-membered ring are shown to be necessary for the stabilization of the radical anions. It was confirmed by the calculation of the total energy using molecular orbital methods that resonance structures involving the double-bond and hydroxyl group provide significant stabilization of the radical anions. Electrochemical preparation may be a useful method for the detailed study of radicals, their molecular structure and reactivity.

  4. Electrochemical examination of the ascorbic acid radical anion in non-aqueous electrolytes

    International Nuclear Information System (INIS)

    A quasi-reversible redox reaction involving ascorbic acid was observed in non-aqueous electrolytes at conductive diamond electrode. The chemical reversibility of these reactions is consistent with ascorbic acid being reduced to the ascorbic acid radical anion in a one-electron process, with subsequent reoxidation to ascorbic acid. This is the first report on the electrochemical production of the ascorbic acid radical anion in non-aqueous electrolytes. Ascorbyl 6-stearate and 4-hydroxy 2(5H)-furanone, which have somewhat similar structures as ascorbic acid, also showed one-electron transfer reduction reaction producing radicals with a single negative charge, suggesting that these compounds follow the same electrochemical behavior as ascorbic acid. The double bond and hydroxyl substituent on the five-membered ring are shown to be necessary for the stabilization of the radical anions. It was confirmed by the calculation of the total energy using molecular orbital methods that resonance structures involving the double-bond and hydroxyl group provide significant stabilization of the radical anions. Electrochemical preparation may be a useful method for the detailed study of radicals, their molecular structure and reactivity

  5. Ascorbic acid antagonizes nicotine-induced place preference and behavioral sensitization in female mice

    Directory of Open Access Journals (Sweden)

    Ali Akbar Aliabadi

    2006-04-01

    Full Text Available Introduction: The influence of ascorbic acid on the nicotine-induced conditioned place preference (CPP and behavioral sensitization was investigated in the present study. Methods: In a pilot study, place conditioning and locomotor activity were investigated after nicotine (0.25, 0.5, 0.75, 1, 1.5 and 2 mg/kg or ascorbic acid (1, 10, 100 and 1000 mg/kg administration. Different doses of ascorbic acid in conditioning days or on the test days were used. Behavioral sensitization was induced in animals by daily intraperitoneal administration of nicotine (0.25 mg/kg for seven cosecutive days followed by one day interval. On 9th day, locomotor activity was induced by ineffective dose of nicotine (0.1 mg/kg. Ascorbic acid was injected 20 min before each injection of nicotine (acquisition of sensitization or acutely 20 min before a challenge nicotine injection (expression of sensitization. Results: The results showed that intraperitoneal nicotine (1 mg/kg administration can induce place preference whereas acute administration of the drug induces catalepsy. Administration of ascorbic acid did not induce place preference nor place aversion and also did not change the locomotor activity. Locomotor sensitization in mice was produced by intraperitoneal injection of nicotine (0.25 mg/kg for 7 consecutive days. On the 9th day of experiments, activity of the mice was recorded after challenge with nicotine (0.1 mg/kg, i.p.. The senisitization was better achived when the ineffective dose of nicotine (0.1 mg/kg was applied. Administration with ascorbic acid reduced both the acquisition and expression of nicotine-induced CPP. It was shown that ascorbic acid attenuated the acquisition of nicotine sensitization in a dose-independent manner but the expression of nicotineinduced sensitization was not affected by ascorbic acid. Conclusion: We conclude that ascorbic acid may interfere with nicotine-induced place preference and behavioral sensitization.

  6. Study of Ascorbic Acid as Iron(III) Reducing Agent for Spectrophotometric Iron Speciation

    OpenAIRE

    Antesar Elmagirbi; Hermin Sulistyarti; Atikah Atikah

    2012-01-01

    The study of ascorbic acid as a reducing agent for iron(III) has been investigated in order to obtain an alternative carcinogenic reducing agent, hydroxylamine, used in spectrophotometric standard method based on the formation of a red-orange complex of Fe(II)-o-phenanthroline. The study was optimised with regards to ascorbic acid concentration as well as pH solution. The results showed that ascorbic acid showed maximum capacity as reducing agent of iron(III) under concentration of 4.46.10-4 ...

  7. Direct Spectrophotometric Determination of L-ascorbic Acid in the Presence of Potassium Cyanide

    OpenAIRE

    Mirsad Salkić; Husejin Keran; Midhat Jašić

    2007-01-01

    A simple and highly sensitive direct spectrophotometric method was developed for the determination of L-ascorbic acid. Potassium cyanide (9.21x10-5 mol dm-3) was used to stabilize ascorbic acid in aqueous medium. The molar absorptivity of the proposed method, which does not require an extraction procedure, was 1.38x104 dm3 mol-1 cm-1 at 264 nm. Beer’s law was obeyed in the concentration range of 0.26 – 12.0 μg ascorbic acid cm-3. Th e relative standard deviation was 1.40 % for the determinati...

  8. Dissolution of haematite in citric acid-EDTA-ascorbic acid mixtures

    International Nuclear Information System (INIS)

    This study is related to the development of a suitable mixture of citric acid, EDTA and ascorbic acid (CEA) for dissolving the haematite deposited on the structural surfaces of cooling water circuits in BWRs. The dissolution experiments were performed with synthetically prepared haematite. The dependence of the dissolution rates on each of the constituents of the mixture has been evaluated using a 'grain model'. It was found to be Langmuirian in the case of citric acid, linear in the case of EDTA and independent of ascorbic acid concentration. The ratio of molar concentration of the ligand to the total iron was varied from 0.5-2.5. Activation energy of the dissolution in a CEA mixture having stoichiometrically excess EDTA has been determined by performing experiments upto 353 K. The highest dissolution was obtained in 11:44:4 mol·m-3 and 2:55:4 mol·m-3 CEA mixtures. (author)

  9. Ascorbic acid and striatal transport of [3H]1-methyl-4-phenylpyridine (MPP+) and [3H]dopamine

    International Nuclear Information System (INIS)

    The inhibition of uptake of [3H]dopamine and [3H]1-methyl-4-phenylpyridine (MPP+) was examined in mouse striatal synaptosomal preparations. Kinetic analysis indicated that ascorbic acid is a noncompetitive inhibitor of [3H]MPP+ uptake. No inhibition of [3H]dopamine uptake is observed. The dopamine uptake blockers, GBR-12909, cocaine, and mazindol strongly inhibit (IC50 3H]dopamine and [3H]MPP+ transport. Nicotine, its metabolites, and other tobacco alkaloids are weak inhibitors except 4-phenylpyridine and lobeline, which are moderate inhibitors of both [3H]dopamine and [3H]MPP+ uptake. These similarities in potencies are in agreement with the suggestion that [3H]MPP+ and [3H] are transported by the same carrier. The differences observed in the alteration of dopaminergic transport and mazindol binding by ascorbic acid suggest that ascorbic acid's effects on [3H]MPP+ transport are related to translocation and/or dissociation processes occurring subsequent to the initial binding event

  10. Pre-sowing application of ascorbic acid and salicylic acid to seed of pumpkin and seedling response to salt

    International Nuclear Information System (INIS)

    The effects of seed soaking with salicylic acid or ascorbic acid on pumpkin seedlings growth under saline (10 dS m/sup -1/) conditions were investigated. Seedlings fresh weight, protein contents, protease and nitrate reductase activities were significantly affected by 15 and 30 mg L/sup -1/ salicylic acid and 30 mg L/sup -1/ ascorbic acid priming treatments, under both normal and saline conditions. Priming reduced the severity of the salt stress, the amelioration was better due to 30 mg L/sup -1/ ascorbic acid or 30 mg L/sup -1/ salicylic acid treatments as these treatments showed best results on seedling growth, fresh and dry matter production under non-saline and saline environments. Application of seed priming with ascorbic acid and salicylic acid in pumpkin ameliorate the adverse effects of salt stress. (author)

  11. Kinetics of Ascorbic Acid Degradation in Un-Pasteurized Iranian Lemon Juice During Regular Storage Conditions

    Directory of Open Access Journals (Sweden)

    Abbasi

    2008-01-01

    Full Text Available The aim of this research was to determine shelf life stability of un-pasteurized lemon juice filled in clear or dark green glass bottles. Presence of light, time and temperature affect the ascorbic acid retention in citrus juices. Bottles were stored at room temperature (27 ± 3 °C and in the refrigerator (3 ± 1 °C. Total soluble solids, total titrable acidity and pH value were measured every three weeks and analysis was carried out on ascorbic acid content by means of titration method in the presence of 2,6-dichlorophenol indophenol. The study was carried out for 12 weeks after which slight changes in color, taste and apparent texture in some samples were observed and ascorbic acid content reduced by 50%. Soluble solids content, pH value and total acidity were 5.5 ° Brix, 2.73 and 5 g/100 mL, respectively which appeared not to be significantly influenced by storage time or conditions. Ascorbic acid content initially at 38.50 mg/100 mL was sharply reduced to about 22 mg/100 mL within the first three weeks of storage. The final ascorbic acid content of all samples was about 15 mg/100 mL. The deteriorative reaction of ascorbic acid in the juice at all conditions followed a first-order kinetic model with activation energy of 137 cal mol-1.

  12. Kinetics of degradation of ascorbic acid by cyclic voltammetry method

    Directory of Open Access Journals (Sweden)

    Grudi? Veselinka V.

    2015-01-01

    Full Text Available Cyclic voltammetry was used to examine the kinetics of degradation of ascorbic acid (AA at different temperatures. It has been shown that the reduction of the concentration of AA in all temperatures follow the kinetics of the first order reaction. The rate constant of the oxidation reaction increases with temperature as follows: 5x10-5; 2x10-4; 1x10-3 and 3x10-3 min-1 at temperatures of 25°C, 35°C, 65°C and 90°C, respectively. The temperature dependence of the rate constant follows Arrhenius equation, and the value of activation energy of the reaction degradation is 48.2 kJ mol-1 . The effect of storage time at a temperature of 90 °C on AA content in fresh juice of green peppers was investigated. It was shown that AA oxidation reaction in the juice is also the first order reaction, while the lower rate constant in relation to the pure AA (5x10-3 min-1 indicates the influence of other substances present in peppers.

  13. Glutathione-ascorbic acid redox cycle and thioredoxin reductase activity in the digestive tract of Leptinotarsa decemlineata (Say).

    Czech Academy of Sciences Publication Activity Database

    Krishnan, Natraj; Kodrík, Dalibor; Kludkiewicz, Barbara; Sehnal, František

    2009-01-01

    Ro?. 39, ?. 3 (2009), s. 180-188. ISSN 0965-1748 R&D Projects: GA ?R(CZ) GA522/06/1591; GA ?R GA522/07/0788 Institutional research plan: CEZ:AV0Z50070508 Keywords : ascorbate/ascorbic acid * ascorbate peroxidase * glutathione-ascorbic acid redox cycle Subject RIV: CE - Biochemistry Impact factor: 3.117, year: 2009

  14. Chemical Characterization and Evolution of Ascorbic Acid Concentration During Dehydration of Rosehip (Rosa eglanteria Fruits

    Directory of Open Access Journals (Sweden)

    Antonio De Michelis

    2007-01-01

    Full Text Available Rose hip fruits possess a high ascorbic acid content, which may partially degrade during dehydration in heated air. In this study, the chemical composition of the fruits was determined in order to study degradation of ascorbic acid as a function of drying temperature. The results indicated that, in effect, the content of this nutrient is reduced. The degradation mechanisms differed according to the drying temperature but the final ascorbic acid content was almost independent from such operating variable. The experimental evidence was used to calculate the degradation kinetic parameters. Though the extent of degradation was important, the final retention of ascorbic acid was considerable (42% in view of the high initial content for this fruit.

  15. A green method for the synthesis of Copper Nanoparticles using L-ascorbic acid

    Scientific Electronic Library Online (English)

    Asim, Umer; Shahid, Naveed; Naveed, Ramzan; Muhammad Shahid, Rafique; Muhammad, Imran.

    2014-09-01

    Full Text Available Chemical Reduction technique was employed to prepared highly stable and dispersed Copper nanoparticles using L-Ascorbic Acid (Vitamin C) as reducing as well as capping agent. In this technique, cupric chloride was used as precursor. The effects of different molar ratios of L-Ascorbic Acid on the con [...] centration and size of copper nanoparticles were studied. The Copper nanoparticles were characterized by X-Ray Diffraction, Atomic Absorption Spectrometry, and Fourier Transform Infrared Spectrometry. The results show that with the increase in the molar ratio of L-ascorbic acid the concentration of Copper nanoparticles were also increased. The average particles size of copper nanoparticle was found in the range of 50-60 nm. The product was kept in ambient conditions for three month but no sedimentation or separation was observed. The use of ascorbic acid makes the process a non-toxic, cost effective and environmental friendly green method.

  16. Copper/ascorbic acid dyad as a catalytic system for selective aerobic oxidation of amines.

    Czech Academy of Sciences Publication Activity Database

    Šrogl, Ji?í; Voltrová, Svatava

    2009-01-01

    Ro?. 11, ?. 4 (2009), s. 843-845. ISSN 1523-7060 Institutional research plan: CEZ:AV0Z40550506 Keywords : copper * ascorbic acid * oxidative deamination Subject RIV: CC - Organic Chemistry Impact factor: 5.420, year: 2009

  17. Study of Ascorbic Acid as Iron(III Reducing Agent for Spectrophotometric Iron Speciation

    Directory of Open Access Journals (Sweden)

    Antesar Elmagirbi

    2012-10-01

    Full Text Available The study of ascorbic acid as a reducing agent for iron(III has been investigated in order to obtain an alternative carcinogenic reducing agent, hydroxylamine, used in spectrophotometric standard method based on the formation of a red-orange complex of Fe(II-o-phenanthroline. The study was optimised with regards to ascorbic acid concentration as well as pH solution. The results showed that ascorbic acid showed maximum capacity as reducing agent of iron(III under concentration of 4.46.10-4 M and pH solution of 1-4.Under these conditions, ascorbic acid reduced iron(III proportionally and performed similarly to that of hydroxylamine.  The method gave result to linear calibration over the range of 0.2-2 mg/L withhigh accuracy of 97 % and relative standard deviation of less than 2 %. This method was successfully applied to assay iron speciation in water samples.

  18. Role of ascorbic acid on tyrosine hydroxylase activity in the adrenal gland of guinea pig

    International Nuclear Information System (INIS)

    The decrease of tyrosine hydroxylase activity in adrenal homogenate in scurvy was recovered after the administration of ascorbic acid. The causes of the increase in the enzyme activity after the administration of ascorbic acid have been studied. 1. No significant elevation in the enzyme activity was observed after the administration of reserpine to the scorbutic guinea pig. 2. A dose of metal chelating agent, ?, ?'-dipyridyl, prevented the ascorbic acid-induced or reserpine-induced increase in enzyme activity in the scorbutic and the nonscorbutic guinea pigs, respectively. 3. Tyrosine hydroxylase activity was partially recovered by the administration of FeSO4 to the scorbutic guinea pig. From these results, it became clear that the induction of tyrosine hydroxylase which was not observed in scurvy was due to the deficiency of Fe2+. These results suggested that ascorbic acid affected the induction of this enzyme via Fe2+. (auth.)

  19. Ascorbic Acid Determination in Natural Orange Juice: As a Teaching Tool of Coulometry and Polarography.

    Science.gov (United States)

    Bertotti, Mauro; And Others

    1995-01-01

    Describes an experiment designed to determine ascorbic acid concentrations in natural orange juice. The experiment is used with undergraduate pharmacy students to allow understanding of the principles of operation of the coulometer and polarograph. (DDR)

  20. Neutralization of local toxicity induced by vipera russelli phospholipase A2 by lipophilic derivative of ascorbic acid.

    Science.gov (United States)

    Mohamed, Riyaz; Shivaprasad, Holenarasipura V; Jameel, Noor M; Shekar, Mysore A; Vishwanath, Bannikuppe S

    2011-01-01

    L-ascorbic acid upon condensation with palmitic acid in the presence of sulphuric acid results in L-ascorbic acid-6-palmitate (AP). The effect of L-ascorbic acid derivative, AP on the pharmacological activities of purified basic multi-toxic PLA2 enzyme, VRV-PL-VIIIa from Vipera russelli snake venom along with in vitro activities is described. AP inhibited VRV-PL-VIIIa enzyme activity in a concentration dependent manner with IC50 value of 48.85 ?M and the inhibition is found to be independent of substrate and calcium concentration. Upon investigating the in vivo pharmacological activities, it has been found that AP inhibited VRV-PL-VIIIa induced mouse paw edematogenic activity in a dose dependant manner. Intramuscular co-injection of AP with VRV-PL-VIIIa (1:10 w:w) neutralized the VRV-PL-VIIIa induced myotoxocity. Sections of mouse thigh muscle showed normal intact musculature with normal levels of serum creatine kinase and lactate dehydrogenase. Histopathological studies showed that administration of VRV-PL-VIIIa (i.p) along with AP mixture inhibited VRV-PL-VIIIa induced lung haemorrhage in mouse indicated that enzyme activity is responsible for all these observed pathological and pharmacological activities. The biophysical interaction studies showed that AP interacted directly with the enzyme and decreased the relative intrinsic fluorescence intensity. CD spectral analysis showed an apparent shift in the far UV-CD spectra of VRV-PL-VIIIa with AP. Docking study also confirmed the interaction of AP with enzyme directly. These results demonstrate that AP neutralizes VRV-PL-VIIIa induced pharmacological activities by inhibiting the enzyme with direct interactions. This compound along with other inhibitors of snake venom hydrolytic enzymes might be of use to neutralize local toxicity of V. russelli venom where antivenoms have failed. PMID:21682683

  1. Old Things New View: Ascorbic Acid Protects the Brain in Neurodegenerative Disorders

    Directory of Open Access Journals (Sweden)

    Adriana Covarrubias-Pinto

    2015-11-01

    Full Text Available Ascorbic acid is a key antioxidant of the Central Nervous System (CNS. Under brain activity, ascorbic acid is released from glial reservoirs to the synaptic cleft, where it is taken up by neurons. In neurons, ascorbic acid scavenges reactive oxygen species (ROS generated during synaptic activity and neuronal metabolism where it is then oxidized to dehydroascorbic acid and released into the extracellular space, where it can be recycled by astrocytes. Other intrinsic properties of ascorbic acid, beyond acting as an antioxidant, are important in its role as a key molecule of the CNS. Ascorbic acid can switch neuronal metabolism from glucose consumption to uptake and use of lactate as a metabolic substrate to sustain synaptic activity. Multiple evidence links oxidative stress with neurodegeneration, positioning redox imbalance and ROS as a cause of neurodegeneration. In this review, we focus on ascorbic acid homeostasis, its functions, how it is used by neurons and recycled to ensure antioxidant supply during synaptic activity and how this antioxidant is dysregulated in neurodegenerative disorders.

  2. Old Things New View: Ascorbic Acid Protects the Brain in Neurodegenerative Disorders.

    Science.gov (United States)

    Covarrubias-Pinto, Adriana; Acuña, Aníbal Ignacio; Beltrán, Felipe Andrés; Torres-Díaz, Leandro; Castro, Maite Aintzane

    2015-01-01

    Ascorbic acid is a key antioxidant of the Central Nervous System (CNS). Under brain activity, ascorbic acid is released from glial reservoirs to the synaptic cleft, where it is taken up by neurons. In neurons, ascorbic acid scavenges reactive oxygen species (ROS) generated during synaptic activity and neuronal metabolism where it is then oxidized to dehydroascorbic acid and released into the extracellular space, where it can be recycled by astrocytes. Other intrinsic properties of ascorbic acid, beyond acting as an antioxidant, are important in its role as a key molecule of the CNS. Ascorbic acid can switch neuronal metabolism from glucose consumption to uptake and use of lactate as a metabolic substrate to sustain synaptic activity. Multiple evidence links oxidative stress with neurodegeneration, positioning redox imbalance and ROS as a cause of neurodegeneration. In this review, we focus on ascorbic acid homeostasis, its functions, how it is used by neurons and recycled to ensure antioxidant supply during synaptic activity and how this antioxidant is dysregulated in neurodegenerative disorders. PMID:26633354

  3. Formulation with ascorbic acid and sucrose modulates catechin bioavailability from green tea

    OpenAIRE

    Peters, Catrina M.; Green, Rodney J.; Janle, Elsa M; Ferruzzi, Mario G.

    2010-01-01

    In order to investigate the impact of common food ingredients on catechin absorption, green tea (GT) extract (50 mg) was formulated plain, with sucrose (GT+S), with ascorbic acid (GT+AA) and with sucrose and ascorbic acid (GT+S+AA). Bioavailability and bioaccessibility were assessed in Sprague Dawley rats and an in vitro digestion/Caco-2 cell model respectively. Absorption of epigallocatechin (EGC) and epigallocatechin gallate (EGCG) was significantly (P

  4. Low-volume plus ascorbic acid vs high-volume plus simethicone bowel preparation before colonoscopy

    OpenAIRE

    Stefano Pontone; Rita Angelini; Monica Standoli; Gregorio Patrizi; Franco Culasso; Paolo Pontone; Adriano Redler

    2011-01-01

    AIM: To investigate the effectiveness of low-volume plus ascorbic acid [polyethylene glycol plus ascorbic acid (PEG + Asc)] and high-volume plus simethicone [polyethylene glycol plus simethicone (PEG + Sim)] bowel preparations. METHODS: A total of one hundred and forty-four outpatients (76 males), aged from 20 to 84 years (median age 59.5 years), who attended our Department, were divided into two groups, age and sex matched, and underwent colonoscopy. Two questionnaires, one for patients repo...

  5. Degradation kinetic modelling of ascorbic acid and colour intensity in pasteurised blood orange juice during storage.

    Science.gov (United States)

    Remini, Hocine; Mertz, Christian; Belbahi, Amine; Achir, Nawel; Dornier, Manuel; Madani, Khodir

    2015-04-15

    The stability of ascorbic acid and colour intensity in pasteurised blood orange juice (Citrus sinensis [L.] Osbeck) during one month of storage was investigated at 4-37 °C. The effects of ascorbic acid fortification (at 100, 200 mg L(-1)) and deaeration, temperature/time storage on the kinetic behaviour were determined. Ascorbic acid was monitored by HPLC-DAD and colour intensity by spectrophotometric measurements. Degradation kinetics were best fitted by first-order reaction models for both ascorbic acid and colour intensity. Three models (Arrhenius, Eyring and Ball) were used to assess the temperature-dependent degradation. Following the Arrhenius model, activation energies were ranged from 51 to 135 kJ mol(-1) for ascorbic acid and from 49 to 99 kJ mol(-1) for colour intensity. The effect of storage temperature and deaeration are the most influent factors on kinetics degradation, while the fortification revealed no significant effect on ascorbic acid content and colour intensity. PMID:25466074

  6. Application of titanium oxide nanotube films containing gold nanoparticles for the electroanalytical determination of ascorbic acid

    International Nuclear Information System (INIS)

    Au/TiO2/Ti electrodes have been prepared by galvanic deposition of gold particles on TiO2 nanotube substrates. Titanium oxide nanotubes are fabricated by anodizing titanium foil in a Dimethyl Sulfoxide electrolyte containing fluoride. The scanning electron microscopy results indicated that gold particles are homogeneously deposited on the surface of TiO2 nanotubes. The TiO2 layers consist of individual tubes of about 40-80 nm diameters. The electro-catalytic behavior of Au/TiO2/Ti and flat gold electrodes for the ascorbic acid electro-oxidation was studied by cyclic voltammetry. The results showed that the flat gold electrode is not suitable for the oxidation of ascorbic acid. However, the Au/TiO2/Ti electrodes are shown to possess catalytic activity toward the oxidation reaction. Catalytic oxidation peak current showed a linear dependence on the ascorbic acid concentration and a linear calibration curve is obtained in the concentration range of 1-5 mM of ascorbic acid. Also, determination of ascorbic acid in real samples was evaluated. The obtained results were found to be satisfactory. Finally the effects of interference on the detection of ascorbic acid were investigated.

  7. Effects of ascorbic acid on some physiological changes of pepino (Solanum muricatum Ait.) under chilling stress.

    Science.gov (United States)

    Sivaci, Aysel; Kaya, A; Duman, Sevcan

    2014-09-01

    In this study, the changes caused by chilling stress on some physiological parameters of pepino (Solanum muricatum Ait.) plant and the effects of ascorbic acid (100 mM) applied exogenously on these changes were examined. For this purpose, the photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophylls and carotenoids), ascorbic acid, total phenolic compounds, malondialdehyde and proline contents in leaves of pepino taken on 5th and 10th days were determined. As a result of chilling stress, it was found that while the photosynthetic pigments and proline contents decreased in pepino leaves, the ascorbic acid, total phenolic compounds and malondialdehyde contents increased. In plants which were subjected to pre-treatment of ascorbic acid on the 10th day of stress, ascorbic acid and proline contents increased while a decrease was observed in malondialdehyde content, compared to stress group without pre-treated. This study may be important for explaining resistance induced by treatment of exogenous ascorbic acid in pepino exposed to chilling stress. PMID:25194734

  8. Flow injection-chemiluminescence determination of ascorbic acid based on luminol–ferricyanide–gold nanoparticles system

    International Nuclear Information System (INIS)

    A novel flow-injection chemiluminescence (CL) method for the determination of ascorbic acid (AA) is proposed, based upon its enhancing effect on the CL reaction of luminol with ferricyanide catalyzed by gold nanoparticles in alkaline solution. Different sizes gold nanoparticles exhibited different catalyzing effect towards luminol CL and 38 nm gold nanoparticles exhibited the best enhancing effect. Under the optimal experimental conditions, a linear relationship was obtained between the CL intensity and the concentration of ascorbic acid in the range of 1.0×10?10–1.0×10?6 mol L?1. The detection limit was 2.0×10–11 mol ?1 and the relative standard deviation for 1.0×10?6 mol L?1 ascorbic acid was 0.71% (n=10). This method has been successfully applied in the determination of ascorbic acid in several real samples. - Highlights: • Gold nanoparticles could enhance luminol–K3Fe(CN)6 CL signal. • 38 nm gold nanoparticles exhibited the best catalyzing effect. • Ascorbic acid could further enhance luminol–K3Fe(CN)6–gold nanoparticles CL. • Ascorbic acid could be detected sensitively based on its enhancing effect

  9. Flow injection-chemiluminescence determination of ascorbic acid based on luminol–ferricyanide–gold nanoparticles system

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Yong Ping, E-mail: dongyp@ahut.edu.cn [School of chemistry and chemical engineering, Anhui University of Technology, Maanshan, China, 243002 (China); Gao, Ting Ting; Chu, Xiang Feng; Chen, Jun [School of chemistry and chemical engineering, Anhui University of Technology, Maanshan, China, 243002 (China); Wang, Cheng Ming, E-mail: chmwang@ustc.edu.cn [Hefei National Laboratory for Physical Science at the Microscale, University of Science and Technology of China, Hefei, China, 230026 (China)

    2014-10-15

    A novel flow-injection chemiluminescence (CL) method for the determination of ascorbic acid (AA) is proposed, based upon its enhancing effect on the CL reaction of luminol with ferricyanide catalyzed by gold nanoparticles in alkaline solution. Different sizes gold nanoparticles exhibited different catalyzing effect towards luminol CL and 38 nm gold nanoparticles exhibited the best enhancing effect. Under the optimal experimental conditions, a linear relationship was obtained between the CL intensity and the concentration of ascorbic acid in the range of 1.0×10{sup ?10}–1.0×10{sup ?6} mol L{sup ?1}. The detection limit was 2.0×10{sup –11} mol {sup ?1} and the relative standard deviation for 1.0×10{sup ?6} mol L{sup ?1} ascorbic acid was 0.71% (n=10). This method has been successfully applied in the determination of ascorbic acid in several real samples. - Highlights: • Gold nanoparticles could enhance luminol–K{sub 3}Fe(CN){sub 6} CL signal. • 38 nm gold nanoparticles exhibited the best catalyzing effect. • Ascorbic acid could further enhance luminol–K{sub 3}Fe(CN){sub 6}–gold nanoparticles CL. • Ascorbic acid could be detected sensitively based on its enhancing effect.

  10. Application of titanium oxide nanotube films containing gold nanoparticles for the electroanalytical determination of ascorbic acid

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini, Mir Ghasem, E-mail: mg-hosseini@tabrizu.ac.ir; Faraji, Masoud; Momeni, Mohamad Mohsen

    2011-03-31

    Au/TiO{sub 2}/Ti electrodes have been prepared by galvanic deposition of gold particles on TiO{sub 2} nanotube substrates. Titanium oxide nanotubes are fabricated by anodizing titanium foil in a Dimethyl Sulfoxide electrolyte containing fluoride. The scanning electron microscopy results indicated that gold particles are homogeneously deposited on the surface of TiO{sub 2} nanotubes. The TiO{sub 2} layers consist of individual tubes of about 40-80 nm diameters. The electro-catalytic behavior of Au/TiO{sub 2}/Ti and flat gold electrodes for the ascorbic acid electro-oxidation was studied by cyclic voltammetry. The results showed that the flat gold electrode is not suitable for the oxidation of ascorbic acid. However, the Au/TiO{sub 2}/Ti electrodes are shown to possess catalytic activity toward the oxidation reaction. Catalytic oxidation peak current showed a linear dependence on the ascorbic acid concentration and a linear calibration curve is obtained in the concentration range of 1-5 mM of ascorbic acid. Also, determination of ascorbic acid in real samples was evaluated. The obtained results were found to be satisfactory. Finally the effects of interference on the detection of ascorbic acid were investigated.

  11. Effect of Supplemental Ascorbic Acid on the Aerobic Capacity in Children

    Directory of Open Access Journals (Sweden)

    Gholamreza Sharifi

    2014-10-01

    Full Text Available Introduction: ascorbic acid is a water-soluble vitamin solved in water that acts as a helper of some the enzymes in the reactions of energy metabolism. Thus, the study aims to investigate the use of supplemental ascorbic acid on the aerobic and anaerobic capacity of the children.Methodology: Participants of this quasi-experimental study were 18 children in Esfahan who were randomly selected and divided into 9 groups in pair (aerobic exercise group and the control group. For 10 days before the start of the main trial, the participants in the control group received placebo and the experimental group received ascorbic acid. The average aerobic capacity was measured before and after 10 days of the use of ascorbic acid. The results were analyzed by SPSS version 18.Results: Before and after 10 days of the use of ascorbic acid, the mean and standard deviation of the aerobic capacity of the experimental group were respectively 3.59± 0.38 and 4.23 ± 0.77 and of the control group were 3.7 ± 0.40 and 3.7± 0.53, respectively. Therefore, there was a significant relationship between the use of ascorbic acid and placebo in terms of aerobic capacity (p ? 0.5.

  12. Candidate genes and quantitative trait loci affecting fruit ascorbic acid content in three tomato populations.

    Science.gov (United States)

    Stevens, Rebecca; Buret, Michel; Duffé, Philippe; Garchery, Cécile; Baldet, Pierre; Rothan, Christophe; Causse, Mathilde

    2007-04-01

    Fresh fruit and vegetables are a major source of ascorbic acid (vitamin C), an important antioxidant for the human diet and also for plants. Ascorbic acid content in fruit exhibits a quantitative inheritance. Quantitative trait loci (QTL) for ascorbic acid content have been mapped in three tomato populations derived from crosses between cultivated tomato varieties (Solanum lycopersicum accessions) and three related wild species or subspecies. The first population consists of a set of introgression lines derived from Solanum pennellii, each containing a unique fragment of the wild species genome. The second population is an advanced backcross population derived from a cross between a cultivated tomato and a Solanum habrochaites (formerly Lycopersicum hirsutum) accession. The third population is a recombinant inbred line population derived from the cross between a cherry tomato line and a large fruited line. Common regions controlling ascorbic acid content have been identified on chromosomes 2, 8, 9, 10, and 12. In general, the wild alleles increased ascorbic acid content, but some improvement could also be provided by S. lycopersicum. Most QTLs appeared relatively stable over years and in different environments. Mapping of candidate genes involved in the metabolism of ascorbic acid has revealed a few colocations between genes and QTLs, notably in the case of a monodehydroascorbate reductase gene and a QTL present in two of the populations on chromosome 9 (bin 9-D), and a previously mapped GDP-mannose epimerase and a QTL on chromosome 9 (bin 9-J). PMID:17277090

  13. Corrosion of PHWR PHT system structural materials by dilute chemical decontamination formulations containing ascorbic acid

    International Nuclear Information System (INIS)

    Decontamination of primary heat transport (PHT) systems of PHWRs is normally carried out using reducing type formulations that contain reducing and complexing agents. Oxalic acid is used as a reductant in many of the commercial and non-commercial formulations. This Paper presents an attempt to evaluate ascorbic acid as a reductant in a chemical formulation. Thermal and radiation stability and corrosion behaviour of ascorbic acid have been evaluated and compared with those for oxalic acid. A formulation containing ethylenediaminetetraacetic acid (EDTA) (400 mg/dm3), ascorbic acid (300 mg/dm3) and citric acid (300 mg/dm3) was evaluated for its compatibility with PHT system construction materials viz. carbon steel, monel-400 and zircaloy-2. (author)

  14. Selective Detection of Dopamine in the Presence of Ascorbic Acid at Poly (m-Aminobenzene Sulfonic Acid)

    OpenAIRE

    Gamze Erdo?du; Mehmet Mutluhan Mutlu

    2011-01-01

    Poly (m-aminobenzene sulfonic acid, m-ABSA) films were electrochemically prepared by cyclic voltammetry (CV) in 0.1 mol L–1 KCl solution. The dopamine (DA) selectivity of polymeric electrodes prepared at the different thicknesses was examined in the presence of ascorbic acid (AA). The results showed that the modified electrode showed an excellent electrocatalytical effect towards oxidation of dopamine (DA) and ascorbic acid (AA). Electrostatic interaction between the negatively charged poly(m...

  15. The effects of dietary ascorbic acid supplementation on collagen and amino acid concentrations in Japanese quails exposed to heat stress

    OpenAIRE

    SEYREK, Kamil; ERBA?, Hakan; Serter, Mukadder; YEN?SEY, Çi?dem

    2010-01-01

    A considerable body of data exists regarding the role of vitamin C in mammalian physiology; however, there are no data about the effects of dietary ascorbic acid supplementation on collagen concentrations and amino acid levels in animals exposed to heat stress. The present study investigated the effects of supplementary ascorbic acid intake on collagen concentrations in the brain and heart tissue in Japanese quails. In addition, glycine, glutamine, histidine, asparagine, and serine contents i...

  16. Synthesis of L-ascorbic acid in the phloem

    Directory of Open Access Journals (Sweden)

    Haupt Sophie

    2003-11-01

    Full Text Available Abstract Background Although plants are the main source of vitamin C in the human diet, we still have a limited understanding of how plants synthesise L-ascorbic acid (AsA and what regulates its concentration in different plant tissues. In particular, the enormous variability in the vitamin C content of storage organs from different plants remains unexplained. Possible sources of AsA in plant storage organs include in situ synthesis and long-distance transport of AsA synthesised in other tissues via the phloem. In this paper we examine a third possibility, that of synthesis within the phloem. Results We provide evidence for the presence of AsA in the phloem sap of a wide range of crop species using aphid stylectomy and histochemical approaches. The activity of almost all the enzymes of the primary AsA biosynthetic pathway were detected in phloem-rich vascular exudates from Cucurbita pepo fruits and AsA biosynthesis was demonstrated in isolated phloem strands from Apium graveolens petioles incubated with a range of precursors (D-glucose, D-mannose, L-galactose and L-galactono-1,4-lactone. Phloem uptake of D-[U-14C]mannose and L-[1-14C]galactose (intermediates of the AsA biosynthetic pathway as well as L-[1-14C]AsA and L-[1-14C]DHA, was observed in Nicotiana benthamiana leaf discs. Conclusions We present the novel finding that active AsA biosynthesis occurs in the phloem. This process must now be considered in the context of mechanisms implicated in whole plant AsA distribution. This work should provoke studies aimed at elucidation of the in vivo substrates for phloem AsA biosynthesis and its contribution to AsA accumulation in plant storage organs.

  17. The effects of ?-tocopherol and ascorbic acid glucosides on radiation- and H2O2-induced decomposition of thymine in aqueous solution

    International Nuclear Information System (INIS)

    The effects of ascorbic acid, ascorbic acid glycoside and ?-tocopherol monoglycoside on radiation- and H2O2-induced decomposition of thymine in aqueous solutions were investigated. Of the three compounds studied, ascorbic acid glycoside was found to possess the most marked protecting properties. An explanation of this phenomenon has been given in terms of differences in molecular structures of ascorbic acid and ascorbic acid glycoside, as well as properties of radical adducts formed during their interaction with OH radicals. (authors)

  18. Simultaneous detection of ascorbic acid, uric acid and homovanillic acid at copper modified electrode

    International Nuclear Information System (INIS)

    The copper was deposited on glassy carbon (GC) and indium tin oxide (ITO) electrodes by electrochemical method. The copper structures on electrode were characterized by atomic force microscope, X-ray diffractometeric pattern and differential pulse voltammetric studies. Optimal conditions for uniform growth of copper structures on the electrode were established. Voltammetric sensor was fabricated using the copper deposited GC electrode for the simultaneous detection and determination of uric acid (UA) and homovanillic acid (HVA) in the presence of excess concentrations of ascorbic acid (AA). The voltammetric signals due to AA and UA oxidation were well separated with a potential difference of 400 mV and AA did not interfere with the measurement of UA and HVA at the GC/Cu electrode. Linear calibration curves were obtained in the concentration range 1-40 ?M for AA and 20-50 ?M for UA at physiological pH and a detection limit of 10 nM of UA in the presence of 10-fold excess concentrations of AA was achieved. The simultaneous detection of submicromolar concentrations of AA, UA and HVA was achieved at the GC/Cu electrode. The practical utility of the present GC/Cu modified electrode was demonstrated by measuring the AA content in Vitamin C tablet, UA content in human urine and blood serum samples with satisfactory results

  19. Effects of Ascorbic Acid, Phytic Acid and Tannic Acid on Iron Bioavailability from Reconstituted Ferritin Measured by an In Vitro Digestion/Caco-2 Cell Model

    Science.gov (United States)

    The effects of ascorbic acid, phytate and tannic acid on Fe bioavailability from Fe supplied as ferritin was compared to FeSO4 using an in vitro digestion/Caco-2 cell model. Horse spleen ferritin (HSF) was chemically reconstituted into a plant-type ferritin (P-HSF). In the presence of ascorbic acid...

  20. Effects of Ascorbic Acid, Phytic Acid and Tannic Acid on Ferritin-Iron Bioavailability as Determined Using an In Vitro Digestion/Caco-2 Cell Model

    Science.gov (United States)

    The effects of ascorbic acid, phytate and tannic acid on Fe bioavailability from Fe supplied as ferritin was compared to FeSO4 using an in vitro digestion/Caco-2 cell model. Horse spleen ferritin (HSF) was chemically reconstituted into a plant-type ferritin (P-HSF). In the presence of ascorbic acid...

  1. Factors affecting ascorbic acid biosynthesis in chickens: III. Effect of dietary fluoride on L-gulonolactone oxidase activity and tissue ascorbic acid (AsA) concentration.

    Science.gov (United States)

    Maurice, D V; Lightsey, S F; Abudabos, A; Toler, J E

    2002-12-01

    The inconsistent beneficial responses to dietary ascorbic acid (AsA) may be due to dietary factors that alter biosynthesis or tissue turnover of AsA. It has been suggested on the basis of altered tissue AsA that dietary fluoride is a determinant of biosynthesis in chickens. Fluoride may enter the food chain of poultry via industrial contamination, feed ingredients and drinking water. The goal of this study was to ascertain whether dietary fluoride at 300 mg/kg influences l-gulonolactone oxidase (GLO) activity in commercial meat-type chickens. The experimental diet was fed from day-old to 3 weeks and responses measured. Growth and feed conversion were not affected by fluoride in the diet. Dietary fluoride neither inhibited nor enhanced GLO activity nor did it increase or decrease AsA concentration in plasma, liver, kidney, adrenal gland and muscle (pectoralis major). Tissue AsA concentration in ascending order was adrenal > liver > kidney > pectoralis major > plasma. The results are consistent with that reported for the rat and calculations based on the results eliminate fluorine contamination for the inconsistent responses of immature chickens to dietary AsA. PMID:12534831

  2. Construction of an optical sensor for the determination of ascorbic acid using ionic liquids as modifier.

    Science.gov (United States)

    Absalan, Ghodratollah; Arabi, Maryam; Tashkhourian, Javad

    2012-01-01

    An optode was designed for an indirect determination of ascorbic acid by using neocuproine, which has been coated on transparent triacetylcellulose film as a membrane. The proposed method is based on the oxidation of ascorbic acid to dehydroascorbic acid with the Cu(II) and neocuproine reagent. The increase in the absorbance value of the optode at the maximum wavelength of 455 nm was related to the ascorbic acid concentration in aqueous samples. The sensitivity of the method was improved by using room-temperature ionic liquid, [C(8)MIM][PF(6)]. The linear dynamic range for the determination of ascorbic acid was 7.4 × 10(-5) - 3.5 × 10(-3) mol L(-1) with a limit of detection of 2.2 × 10(-5) mol L(-1) (n = 10) and a response time range of 6.0 - 8.0 min. The optode was successfully applied for the determination of ascorbic acid in orange juice. PMID:23232246

  3. Determination of L-Ascorbic Acid in Pharmaceutical Preparations Using Direct Ultraviolet Spectrophotometry

    Directory of Open Access Journals (Sweden)

    Mirsad Salkić

    2009-12-01

    Full Text Available A new, selective and accurate direct ultraviolet spectrophotometric method was developed for the determination of L-ascorbic acid in pharmaceuticals. The oxidation of L-ascorbic acid by iodate in an acidic medium was used as a means of correcting for background absorption. The molar absorptivity of the proposed method was found to be 8.71x103 dm3 mol-1 cm-1 at 250 nm. Beer’s law was obeyed in the concentration range of 0.46 – 16.00 μg cm-3 for L-ascorbic acid. The relative standard deviation was 0.67 % for a concentration of 8.00 μg cm-3 of ascorbic acid (n = 7. The ingredients commonly found in vitamin C and multivitamin products did not interfere. The proposed procedure was successfully applied to assays of L-ascorbic acid in pharmaceutical preparations. The results obtained with the proposed method showed good agreement with those given by the titrimetric method using iodine.

  4. A study of the peroxidation of fatty acid micelles promoted by ionizing radiation, hydrogen peroxide and ascorbate

    International Nuclear Information System (INIS)

    The kinetics of peroxidation of fatty acid micelles promoted by ionizing radiation, hydrogen peroxide and ascorbate were compared. At the dose-rate range of ionizing radiation studied, the higher the dose-rate, the greater the total dose required to produce the same effect. With ascorbate, the rate of lipid peroxidation was dependent on the concentration of the promoter only up to 1 x 10-4M, beyond which a decreasing rate of peroxidation induction was observed. Higher concentration of ascorbate also suppressed the promoting effect of ionizing radiation. Formate, a hydroxyl radical scavenger, inhibited the peroxidation process promoted by these three agents. Caesium was found to be slightly inhibitory. EDTA and deoxycholate were also inhibitory, which may be attributed to iron-chelating and micelle-disrupting capacity, respectively. Addition of iron (Fe2+ or Fe3+) to EDTA-chelated fatty acid micelles re-initiated the peroxidation process. The ease of fatty acid oxidation at pH 7.5 was arochidonic (20:4)>linolenic (18:3)>linoleic (18:2). This order was reversed at pH 11.5. Similarities in the kinetics of peroxidation obtained suggest that certain biological sequelae encountered in cells treated with these seemingly dissimilar agents might arise through some common mechanism(s). (author)

  5. Relief of delayed oxidative stress by ascorbic acid can suppress radiation-induced cellular senescence in mammalian fibroblast cells.

    Science.gov (United States)

    Kobashigawa, Shinko; Kashino, Genro; Mori, Hiromu; Watanabe, Masami

    2015-03-01

    Ionizing radiation-induced cellular senescence is thought to be caused by nuclear DNA damage that cannot be repaired. However, here we found that radiation induces delayed increase of intracellular oxidative stress after irradiation. We investigated whether the relief of delayed oxidative stress by ascorbic acid would suppress the radiation-induced cellular senescence in Syrian golden hamster embryo (SHE) cells. We observed that the level of oxidative stress was drastically increased soon after irradiation, then declined to the level in non-irradiated cells, and increased again with a peak on day 3 after irradiation. We found that the inductions of cellular senescence after X-irradiation were reduced along with suppression of the delayed induction of oxidative stress by treatment with ascorbic acid, but not when oxidative stress occurred immediately after irradiation. Moreover, treatment of ascorbic acid inhibited p53 accumulation at 3 days after irradiation. Our data suggested a delayed increase of intracellular oxidative stress levels plays an important role in the process of radiation-induced cellular senescence by p53 accumulation. PMID:25958121

  6. The comparison of techniques and methods for L-ascorbic acid determination in the fruits

    Directory of Open Access Journals (Sweden)

    Cvetkovi? Biljana R.

    2012-01-01

    Full Text Available Vitamin C is an essential vitamin for human nutrition; with the L-ascorbic acid (AA being the active form of vitamin C. Hence, determination of the L-ascorbic acid in the natural and processed foods is very important. In the past, plenty of methods based on the reversible redox reaction of AA oxidation/DHA reduction were developed. Because of L-ascorbic acid instability in aqueous solutions, it is useful to analyze various types of extraction. The aim of this study is to compare three different methods and three different extractants for the L-ascorbic acid determination. Fruits (kiwi, lemon, orange, and grapefruit were purchased from a local market. The L-ascorbic acid in these four samples was determined by the three different methods: the AOAC, the HPLC method with three different types of extractions, and the colorimetric method using ascorbate-oxidase. For the HPLC measurements, one part of the fruits was extracted with distilled water, the second with potassium hydrogen phosphate, and the third with 3% meta-phosphoric acid (MPA in 8% acetic acid. The HPLC measurements of each sample were repeated three times, the AOAC titration was repeated five times, and in the calorimetric method three measurements were performed. The results were statistically evaluated related to sample basis. Statistical analysis shows that there is a significant difference between the results for all three methods of extraction for all samples, except for the grapefruit sample where no significant difference was observed between the results obtained after the buffer extraction (E2 and the metaphosphoric acid in acetic acid extraction (E3. Discriminative analysis for the HPLC determinations proves that there is a clear difference and defined border between the samples in relation to the methods of extraction during the HPLC determination.

  7. Ascorbic acid protects lipids in human plasma and low-density lipoprotein against oxidative damage

    Energy Technology Data Exchange (ETDEWEB)

    Frei, B. (Department of Nutrition, Harvard School of Public Health, Boston, MA (Unites States))

    1991-12-01

    The authors exposed human blood plasma and low-density lipoprotein (LDL) to many different oxidative challenges and followed the temporal consumption of endogenous antioxidants in relation to the initiation of oxidative damage. Under all types of oxidizing conditions, ascorbic acid completely protects lipids in plasma and LDL against detectable peroxidative damage as assessed by a specific and highly sensitive assay for lipid peroxidation. Ascorbic acid proved to be superior to the other water-soluble plasma antioxidants bilirubin, uric acid, and protein thiols as well as to the lipoprotein-associated antioxidants alpha-tocopherol, ubiquinol-10, lycopene, and beta-carotene. Although these antioxidants can lower the rate of detectable lipid peroxidation, they are not able to prevent its initiation. Only ascorbic acid is reactive enough to effectively intercept oxidants in the aqueous phase before they can attack and cause detectable oxidative damage to lipids.

  8. Investigations on protonation constants and thermodynamic parameters of ascorbic acid, used in decontamination of reactor coolant channels

    International Nuclear Information System (INIS)

    The protonation equilibria for ascorbic acid in ionic strength of 1.0 mol/dm3 NaClO4 medium have been studied using pH-potentiometrically. The protonation constants of ascorbic acid and the thermodynamic functions (?G0, ?H0, and ?S0) for the successive and overall protonation processes of ascorbic acid have been derived at three different temperatures. A detailed thermodynamic analysis of the effects of temperature and ascorbic acid concentration influencing the protonation processes is presented and discussed to determine the factors which control these processes. (author)

  9. Oxidation in fish oil enriched mayonnaise : Ascorbic acid and low pH increase oxidative deterioration

    DEFF Research Database (Denmark)

    Jacobsen, Charlotte; Timm Heinrich, Maike

    2001-01-01

    The effect of ascorbic acid (0-4000 ppm) and pH (3.8-6.2) on oxidation and levels of iron and copper in various fractions of mayonnaise enriched with 16% fish oil was investigated. Ascorbic acid induced release of iron from the assumed oil- water interface into the aqueous phase at all pH levels, but this effect of ascorbic acid was strongest at low pH (pH 3.8- 4.2). Ascorbic acid generally promoted formation of volatile oxidation compounds and reduced the peroxide value in mayonnaises. Peroxide values and total volatiles generally increased with decreasing pH values, suggesting that low pH promoted oxidation. It is proposed that iron bridges between the egg yolk proteins low-density lipoproteins, lipovitellin, and phosvitin at the oil-water interface are broken at low pH values, whereby iron ions become accessible as oxidation initiators. In the presence of ascorbic acid, oxidation is further enhanced due to the reduction of Fe3+ to Fe2+ that rapidly catalyzes lipid oxidation via lipid hydroperoxide decomposition at the oil-water interface in mayonnaise

  10. Electrochemical oxidation of ascorbic acid mediated by carbon nano tubes/ Li+/ carbon paste modified solid electrode

    International Nuclear Information System (INIS)

    Multi-walled carbon nano tube (MWCNT) was used to modify BPPG electrode because of its unique structure and extraordinary properties. MWCNT modified electrode exhibited obvious enhancing and electro catalyzing effects to the oxidation of ascorbic acid using cyclic voltammetry technique. MWCNT was bonded on BPPG electrode surface using carbon paste with ratio of 30 % (w/ W) carbon paste (binder): 70 % (w/ w) MWCNT. This method of modification has lowered the capacitance background current and enabled lower detection limit of ascorbic acid concentration. The electrical conductivity property of MWCNT modified electrode was further improved with the intercalation with lithium ion and resulted in current enhancement of 2 times on the oxidation current of ascorbic acid. Parameters of pH and temperature showed significant relation to the sensitivity of MWCNT modified electrode. Under the optimized parameters, the calibration curve constructed was linear up from 50 μM to 5 mM with sensitivity of 34.5 mA M-1. The practical application of MWCNT modified electrode was demonstrated with Vitamin C pill and orange juice. Good reproducibility and recovery of ascorbic acid concentration showed the feasibility of MWCNT modified electrode to be used in the detection of ascorbic acid in aqueous solution. This also proposed MWCNT modified BPPG electrode possessed advantages such as low detection limit, high stability, low cost and simplicity in fabrication. (author)

  11. The decay of ascorbic acid in a model wine system at low oxygen concentration.

    Science.gov (United States)

    Wallington, Nadja; Clark, Andrew C; Prenzler, Paul D; Barril, Celia; Scollary, Geoffrey R

    2013-12-01

    The present study investigated the impact of temperature on the degradation of ascorbic acid in low oxygen conditions in a model white wine. The concentrations of ascorbic acid, furfural, sulfur dioxide and phenolic-type products were monitored in a model white wine stored under non-oxidative conditions at 45.0, 36.5 and 24.0 °C for up to 693 days. The concentrations of both ascorbic acid and sulfur dioxide decreased over the analysis period while furfural and other colourless phenolic products increased in concentration, despite the presence of residual sulfur dioxide. The decay of ascorbic acid in the low oxygen conditions followed first-order kinetics and the rate constants were determined to be (3.5±0.2)×10(-8), (1.02±0.07)×10(-8), and (0.184±0.009)×10(-8) s(-1) for 45.0, 36.5 and 24.0 °C (n=5, standard error), respectively, and the activation energy was 110±3 kJ/mol (n=3, standard error). Importantly, these data allow more accurate prediction of the temperature-induced loss of ascorbic acid in low oxygen conditions during transport or storage of wine. PMID:23871070

  12. Binding of ascorbic acid and ?-tocopherol to bovine serum albumin: a comparative study.

    Science.gov (United States)

    Li, Xiangrong; Wang, Gongke; Chen, Dejun; Lu, Yan

    2014-02-01

    Binding of ascorbic acid (water-soluble antioxidant) and ?-tocopherol (lipid-soluble antioxidant) to bovine serum albumin (BSA) has been studied using isothermal titration calorimetry (ITC), in combination with fluorescence spectroscopy, UV-vis absorption spectroscopy and Fourier transform infrared (FT-IR) spectroscopy. Thermodynamic investigations reveal that ascorbic acid/?-tocopherol binding to BSA is driven by favorable enthalpy and unfavorable entropy, and the major driving forces are hydrogen bonding and van der Waals forces. For ascorbic acid, the interaction is characterized by a high number of binding sites, which suggests that binding occurs by a surface adsorption mechanism that leads to coating of the protein surface. For ?-tocopherol, one molecule of ?-tocopherol combines with one molecule of BSA and no more ?-tocopherol binding to BSA occurs at concentration ranges used in this study. Fluorescence experiments suggest that ascorbic acid has predominantly a "sphere of action" quenching mechanism, whereas, for ?-tocopherol, the quenching mechanism is "static quenching" and due to the formation of a ground state complex. Additionally, as shown by the UV-vis absorption, synchronous fluorescence spectroscopy, and FT-IR, ascorbic acid and ?-tocopherol may induce conformational and microenvironmental changes of BSA. PMID:24310979

  13. Preparation and Characterization of Poly(D,L-Lactide-co-Glycolide Nanoparticles Containing Ascorbic Acid

    Directory of Open Access Journals (Sweden)

    Magdalena M. Stevanovi?

    2007-09-01

    Full Text Available This paper is covering new, simplistic method of obtaining the system for controlled delivery of the ascorbic acid. Copolymer poly (D,L-lactide-co-glycolide (DLPLG nanoparticles are produced using physical method with solvent/nonsolvent systems where obtained solutions were centrifuged. The encapsulation of the ascorbic acid in the polymer matrix is performed by homogenization of water and organic phases. Particles of the DLPLG with the different content of ascorbic acid have different morphological characteristics, that is, variable degree of uniformity, agglomeration, sizes, and spherical shaping. Mean sizes of nanoparticles, which contain DLPLG/ascorbic acid in the ratio 85/150%, were between 130 to 200 nm depending on which stereological parameters are considered (maximal diameters Dmax, feret X, or feret Y. By introducing up to 15% of ascorbic acid, the spherical shape, size, and uniformity of DLPLG particles are preserved. The samples were characterized by infrared spectroscopy, scanning electron microscopy, stereological analysis, and ultraviolet spectroscopy.

  14. Dietary ascorbic acid and subsequent change in body weight and waist circumference

    DEFF Research Database (Denmark)

    Larsen, Sofus C; Angquist, Lars; Ahluwalia, Tarunveer Singh; Skaaby, Tea; Roswall, Nina; Tjønneland, Anne; Halkjær, Jytte; Overvad, Kim; Pedersen, Oluf; Hansen, Torben; Linneberg, Allan; Husemoen, Lise Lotte N; Toft, Ulla; Heitmann, Berit L; Sørensen, Thorkild I A

    2014-01-01

    BACKGROUND: Cross-sectional data suggests that a low level of plasma ascorbic acid positively associates with both Body Mass Index (BMI) and Waist Circumference (WC). This leads to questions about a possible relationship between dietary intake of ascorbic acid and subsequent changes in anthropome......BACKGROUND: Cross-sectional data suggests that a low level of plasma ascorbic acid positively associates with both Body Mass Index (BMI) and Waist Circumference (WC). This leads to questions about a possible relationship between dietary intake of ascorbic acid and subsequent changes in...... anthropometry, and whether such associations may depend on genetic predisposition to obesity. Hence, we examined whether dietary ascorbic acid, possibly in interaction with the genetic predisposition to a high BMI, WC or waist-hip ratio adjusted for BMI (WHR), associates with subsequent annual changes in weight...... (?BW) and waist circumference (?WC). METHODS: A total of 7,569 participants' from MONICA, the Diet Cancer and Health study and the INTER99 study were included in the study. We combined 50 obesity associated single nucleotide polymorphisms (SNPs) in four genetic scores: a score of all SNPs and a score...

  15. Electrocatalysis and Determination of Ascorbic Acid Through Graphite Paste Electrode Modified With Iron Nitroprusside

    Scientific Electronic Library Online (English)

    Devaney R. do, Carmo; Ricardo M. da, Silva; Nelson R., Stradiotto.

    Full Text Available Iron nitroprusside, Fe(II)NP was incorporated into a carbon paste electrode and the electrochemical studies were performed by cyclic voltammetry. The cyclic voltammogram of the modified electrode, Fe(II)NP showed two redox couples ( E½ox)1 = 0.24 and (E½ox)2 = 0.85 V vs. SCE attributed to Fe(II)/Fe( [...] III) and Fe(II)(CN)5NO / Fe(III)(CN)5NO, respectively. The redox couple at (E½ox)1 = 0.24 V presents an electrocatalytic response for ascorbic acid. The modified paste electrode exhibits a decrease of 180 mV in the ascorbic acid oxidation. The modified graphite paste electrode gives a linear range from 1.0 × 10-3 to 2.6 × 10-2 mol L-1 of ascorbic acid with a detection limit of 1.4 × 10-3 (±1.2%) mol L-1 (n =3). The electrocatalytic oxidation of ascorbic acid compounds by the mediator has been used for the determination of ascorbic acid in a commercially pharmaceutical available product.

  16. Electrocatalysis and Determination of Ascorbic Acid Through Graphite Paste Electrode Modified With Iron Nitroprusside

    Directory of Open Access Journals (Sweden)

    Devaney R. do Carmo

    2004-01-01

    Full Text Available Iron nitroprusside, Fe(IINP was incorporated into a carbon paste electrode and the electrochemical studies were performed by cyclic voltammetry. The cyclic voltammogram of the modified electrode, Fe(IINP showed two redox couples ( E½ox1 = 0.24 and (E½ox2 = 0.85 V vs. SCE attributed to Fe(II/Fe(III and Fe(II(CN5NO / Fe(III(CN5NO, respectively. The redox couple at (E½ox1 = 0.24 V presents an electrocatalytic response for ascorbic acid. The modified paste electrode exhibits a decrease of 180 mV in the ascorbic acid oxidation. The modified graphite paste electrode gives a linear range from 1.0 × 10-3 to 2.6 × 10-2 mol L-1 of ascorbic acid with a detection limit of 1.4 × 10-3 (±1.2% mol L-1 (n =3. The electrocatalytic oxidation of ascorbic acid compounds by the mediator has been used for the determination of ascorbic acid in a commercially pharmaceutical available product.

  17. The Effect of Ascorbic Acid on Mancozeb-Induced Toxicity in Rat Thymocytes.

    Science.gov (United States)

    Pavlovic, V; Cekic, S; Kamenov, B; Ciric, M; Krtinic, D

    2015-01-01

    Mancozeb, as a dithiocarbamate fungicide, has been found to exhibit toxicological manifestations in different cells, mainly by generation of free radicals which may alter antioxidant defence systems in cells. The effect of mancozeb on the cells of a primary lymphoid organ has not been studied. In the present study, the effects of mancozeb (0.2, 2 and 5 ?g/ml) or mancozeb+ascorbic acid (100 ?g/ml), or ascorbic acid alone or control medium alone on the levels of cell viability, apoptosis, intracellular reactive oxygen species production (ROS), mitochondrial membrane potential (MMP) and ATP levels in rat thymocytes were examined in vitro. Cells treated with mancozeb displayed a concentration-dependent increase of hypodiploid cells and ROS production followed by markedly decreased viability of the cells, MMP and ATP levels. Application of ascorbic acid significantly reduced cytotoxicity in cell cultures treated with 0.2 and 2 ?g/ml of mancozeb, together with significantly decreased ROS levels and increased MMP and ATP levels. In cells treated with 5 ?g/ml of mancozeb, ascorbic acid failed to reduce toxicity while simultaneously increasing the apoptosis rate of thymocytes. These results suggest that ROS plays a significant role in mancozeb-induced toxicity, through alteration of mitochondrial function. Ascorbic acid administration reduced the toxicity rate in cells treated with lower mancozeb concentrations, while it may have the ability to shift cells from necrosis to apoptosis in the presence of highest mancozeb concentrations. PMID:26213857

  18. Ascorbic acid protects against restraint stress-induced memory deficits in wistar rats

    Scientific Electronic Library Online (English)

    Raju Suresh, Kumar; Sareesh Naduvil, Narayanan; Satheesha, Nayak.

    Full Text Available OBJECTIVE: Chronic stress has been shown to cause oxidative damage in the central nervous system. Although stress-induced impairments in learning and memory have been studied extensively, very few studies have investigated possible ways to prevent their ill effects. The present work was designed to [...] study the protective effects of ascorbic acid in memory loss induced by chronic restraint stress. METHODS: Adult male Wistar rats were designated into the following groups: (i) Normal control, (ii) Ascorbic acid treatment, (iii) Vehicle control, (iv) Restraint stress, (v) Restraint stress + vehicle, and (vi) Restraint stress + ascorbic acid treatment. At the end of 21 days, animals of all groups were subjected to memory tests using Morris water maze and passive avoidance apparatus. Then, the results obtained were compared between the experimental groups. RESULTS: Rats exposed to restraint stress alone and those pretreated with vehicle solution before restrained stress showed deficits in learning and impaired memory retention in the memory tests when compared to animals in other experimental groups. Animals pretreated with ascorbic acid before restraining showed significant improvement in memory retention in the same memory tests. CONCLUSIONS: Results of this study suggest the possibility of using ascorbic acid as a dietary supplement to prevent stress-induced memory impairments.

  19. Kinetics of Ascorbic Acid Degradation in Un-Pasteurized Iranian Lemon Juice During Regular Storage Conditions

    OpenAIRE

    Abbasi; M. Niakousari

    2008-01-01

    The aim of this research was to determine shelf life stability of un-pasteurized lemon juice filled in clear or dark green glass bottles. Presence of light, time and temperature affect the ascorbic acid retention in citrus juices. Bottles were stored at room temperature (27 ± 3 °C) and in the refrigerator (3 ± 1 °C). Total soluble solids, total titrable acidity and pH value were measured every three weeks and analysis was carried out on ascorbic acid content by means of titration method...

  20. Effects of low-dose irradiation on the free amino acid, glucose and ascorbic acid contents of potato

    International Nuclear Information System (INIS)

    Free amino acid, glucose and ascorbic acid contents of potato with doses of 0.05, 0.1 and 0.15 kGy have been investigated immediately after irradiation. Aspartic acid and glutamic acid decreased about 50 % at a dose of 0.15 kGy. An increase in the glucose content has been observed with increase in radiation doses. A decrease of approximately 20, 36 and 43 % in ascorbic acid was observed in 0.05, 0.10 and 0.15 kGy irradiated potatoes than that of the unirradiated one. (author)

  1. Ascorbic acid glycation of lens proteins produces UVA sensitizers similar to those in human lens

    Energy Technology Data Exchange (ETDEWEB)

    Ortwerth, B.J.; Linetsky, Mikhail; Olesen, P.R. [Missouri Univ., Columbia, MO (United States). Mason Inst. of Ophthalmology

    1995-09-01

    Soluble calf lens proteins were extensively glycated during a 4 week incubation with ascorbic acid in the presence of oxygen. Amino acids analysis of the dialyzed proteins removed at weekly intervals showed an increasing loss of lysine, arginine and histidine, consistent with the extensive protein cross-linking observed. Irradiation of the dialyzed samples with UVA light (1.0 kJ/cm{sup 2} total illumination through a 338 nm cutoff filter) caused an increasing loss of tryptophan, an additional loss of histidine and the production of micromolar concentrations of hydrogen peroxide. No alteration in amino acid content and no photolytic effects were seen in proteins incubated without ascorbic acid in proteins incubated with glucose for 4 weeks. The rate of hydrogen peroxide formation was linear with each glycated sample with a maximum production of 25 nmol/mg protein illuminated. The possibility that the sensitizer activity was due to an ascorbate-induced oxidation of tryptophan was eliminated by the presence of a heavy metal ion chelator during the incubation and by showing equivalent effects with ascorbate-incubated ribonuclease A, which is devoid of tryptophan. The ascorbate-incubated samples displayed increasing absorbance at wavelengths above 300 nm and increasing fluorescence (340/430) as glycation proceeded. The spectra of the 4 week glycated proteins were identical to those obtained with a solubilized water-insoluble fraction from human lens, which is known to have UVA sensitizer activity. (Author).

  2. EFFECTS OF ASCORBIC ACID AND ACETYLSALICYLIC ACID SUPPLEMENTATION ON THE PERFORMANCE OF BROILER CHICKS EXPOSED TO HEAT STRESS

    Directory of Open Access Journals (Sweden)

    B. Anwar, S. A. Khan, A. Aslam, A. Maqbool1 and K. A. Khan

    2004-07-01

    Full Text Available A total of 100, day-old broiler chicks were randomly divided into 5 equal groups and kept under elevated temperature (93-97oF to see the effect of ascorbic acid and acetylsalicylic acid on the feed conversion ratio (FCR, immune status and ratio of weight of bursa, thymus and spleen to body weight. Heat stress increased the FCR but decreased the immune response and ratio of bursa, thymus and spleen to body weight of the birds. Ascorbic acid and acetylsalicylic acid supplementation during heat stress had beneficial effects on FCR, immune status and ratio of bursa, thymus and spleen to body weight. Grossly, bursa, thymus and spleen of heat stressed birds were atrophied but in ascorbic acid and acetylsalicylic acid supplemented birds these organs were not atrophied. No specific histopathological changes were observed in all groups.

  3. Enhancement of the Electrical Properties of CVD-Grown Graphene with Ascorbic Acid Treatment

    Science.gov (United States)

    Tang, Chunmiao; Chen, Zhiying; Zhang, Haoran; Zhang, Yaqian; Zhang, Yanhui; Sui, Yanping; Yu, Guanghui; Cao, Yijiang

    2016-02-01

    Ascorbic acid was used to modify to chemical vapor deposition (CVD)-grown graphene films transferred onto SiO2 substrate. Residual polymer (polymethyl methacrylate), Fe3+, Cl-, H2O, and O2 affected the electrical and thermal properties on graphene during the transfer or device fabrication processes. Exposure of transferred graphene to ascorbic acid resulted in significantly enhanced electrical properties with increased charge carrier mobility. All devices exhibited more than 30% improvement in room temperature carrier mobility in air. The carrier mobility of the treated graphene did not significantly decrease in 21 days. This result can be attributed to electron donation to graphene through the -OH functional group in ascorbic acid that is absorbed in graphene. This work provides a method to enhance the electrical properties of CVD-grown graphene.

  4. Spectrophotometric determination of uranium using ascorbic acid as a chromogenic reagent

    International Nuclear Information System (INIS)

    A spectrophotometric method has been developed for the determination of uranium(VI) using ascorbic acid. Uranium in the hexavalent state forms a reddish-brown coloured complex with ascorbic acid. The colour intensity of the complex is maximum at pH 4.2-4.5 and is stable for 24 hr. The absorbances of uranium(VI)-ascorbic acid complex at 360 and 450 nm are used for its quantification. Uranium in the range 8-200 μg/ml has been determined with good precision. The method allows the determination of uranium in the presence of many metal ions present as impurities. The described method is simple, accurate and applicable to uranium concentration relevant to the PUREX process and thus can be used for analytical control purposes. (author)

  5. Modulatory Effects of Ascorbic Acid and ?-tocopherol on Arsenic Induced Micronuclei Formation

    Directory of Open Access Journals (Sweden)

    R. Suresh

    2010-01-01

    Full Text Available Arsenic is a well known human carcinogen and has many other toxic effects. Sodium arsenite, a compound of arsenic, capable of inducing genotoxic effects through oxidative stress, is evaluated for its genotoxic effect by the formation of micronuclei in the polychromatic erythrocytes in the bone marrow cells of Wistar rats. Further, the modulatory effects of antioxidants like ascorbic acid and ?-tocopherol on arsenic intoxicated rats is investigated. Therefore, the present study was designed to determine whether the oral supplementation of ?-tocopherol (400 mg kg-1 body weight and ascorbic acid (200 mg kg-1 b.wt. to arsenic-intoxicated rats (100 ppm in drinking water for 30 days, modulates the genotoxicity caused by arsenic through the formation of micronuclei (p<0.05. The findings suggest that co-treatment of ascorbic acid and ?-tocopherol to arsenic-exposed rats protects the antioxidant system and modulates arsenic induced micronuclei formation.

  6. Oxidation in fish oil enriched mayonnaise : Ascorbic acid and low pH increase oxidative deterioration

    DEFF Research Database (Denmark)

    Jacobsen, Charlotte; Timm Heinrich, Maike; Meyer, Anne S.

    2001-01-01

    The effect of ascorbic acid (0-4000 ppm) and pH (3.8-6.2) on oxidation and levels of iron and copper in various fractions of mayonnaise enriched with 16% fish oil was investigated. Ascorbic acid induced release of iron from the assumed oil- water interface into the aqueous phase at all pH levels......H promoted oxidation. It is proposed that iron bridges between the egg yolk proteins low-density lipoproteins, lipovitellin, and phosvitin at the oil-water interface are broken at low pH values, whereby iron ions become accessible as oxidation initiators. In the presence of ascorbic acid, oxidation is...... further enhanced due to the reduction of Fe3+ to Fe2+ that rapidly catalyzes lipid oxidation via lipid hydroperoxide decomposition at the oil-water interface in mayonnaise...

  7. Electrochemical impedance based chiral analysis of anti-ascorbutic drug: l-Ascorbic acid and d-ascorbic acid using C-dots decorated conductive polymer nano-composite electrode.

    Science.gov (United States)

    Pandey, Indu; Kant, Rama

    2016-03-15

    Clinical manifestations owing to l-ascorbic acid for scurvy as comparison to d-ascorbic acid and challenges of chiral purity are overcome by using chiral selective conductive polymer nanocomposite which mimics antibodies and enzymes. A novel chiral selective imprinted polyaniline-ferrocene-sulfonic acid film has been electrochemically fabricated on C-dots modified pencil graphite electrode. The performance of the obtained l-ascorbic acid or d-ascorbic acid chiral selective sensor was investigated by electrochemical impedance spectroscopy, cyclic and differential pulse voltammetry. The surface characteristics of the C-dots, chiral sensor before and after the de-doping of chiral d- and l-ascorbic acid were characterized by scanning electron microscopy, Raman spectroscopy and X-ray diffraction spectroscopy. Excellent recognition results were obtained by difference in electron transfer resistance. The proposed chiral sensor is capable of measuring d-ascorbic acid or l-ascorbic acid in aqueous as well as in real and commercial samples within the range of 0.020-0.187nM and 0.003-0.232nM with detection limit of 0.00073nM and 0.00016nM, respectively. The proposed method has also been examined for the chiral selective recognition of ascorbic acid isomers (d- and l-) quantitatively, in complicated matrices of real samples. PMID:26499067

  8. Effects of Ascorbic Acid and Mono- and Diglycerides on Taftoon Bread Quality

    Directory of Open Access Journals (Sweden)

    M. Shahedi

    2001-10-01

    Full Text Available The quality of Iranian breads has intensively decreased during recent years due to socio-economic factors and poor quality of flour. The purpose of this study is to investigate the effects of mono- and diglycerides and ascorbic acid as improvers on Iranian bread (Taftoon quality. Three wheat type flours (Ghods, Mahdavi and Roshan wheat varieties produced in Isfahan region were used. The effects of ascorbic acid at three levels (20, 40 and 60 ppm flour basis and esters of mono- and diglycerides at three levels (0.5, 1.0 and 1.5 percent on the dough baking and bread quality were measured. The Taftoon bread was baked in a semi-traditional oven. Loaves of bread were scored after baking and also on the first and second days of storage at room temperature. Analysis of variances indicated that ascorbic acid and mono- and diglycerides have significant effects on the improvement of the rheological properties of dough. However, ascorbic acid had higher effects than mono- and diglycerides. The results of the tests showed that dough resistance to mixing and tensile stress increased with addition of the improvers. Both improvers used in this experiment have an anti-stabling effect on bread. However, the ascorbic acid effect is much less than that of mono- and diglyceride. The low concentration of 0.5 percent of mono- and diglyceride and 60 ppm of ascorbic acid with flours of moderate protein contents (10-11% resulted in good quality Taftoon bread with good organoleptic and tearing qualities after two days.

  9. Preventive activity of ascorbic acid on lead acetate induced cerebellar damaged in adult Wistar rats

    Directory of Open Access Journals (Sweden)

    Sunday Abraham Musa

    2012-12-01

    Full Text Available Among the environmental contaminants, lead is one of the most hazardous to living matter. In mammals, the main target is the central nervous system, particularly in the young. Ascorbic acid is an antioxidant which is a substance that may protect your cells against the effects of free radicals. This study investigated Experiment the protective effect of ascorbic acid on the cerebellum of adult Wistar rats following oral administration of different doses of Lead acetate. Thirty adult Wistar rats of average weight of 215g were used in this study. The animals were divided into five (5 groups of six animals per group and were administered different doses of lead acetate (60mg/kg bwt of 1/10th LD50 and 30mg/kg bwt of 1/20th of LD50 and ascorbic acid (4.3mg/kg bwt orally over a period of three (3 weeks.Group 1 (control was administered distilled water and Group 2 and 3 were administered 30mg/kg and 60mg/kg of Lead acetate respectively while Group 4 and 5 were given co-administration of 30mg/kg of Lead acetate 4.3mg/kg of ascorbic acid and 60gm/kg of Lead acetate 4.3mg/kg of ascorbic acid respectively. Histopathologically, Lead acetate induced cellular damage in the cerebellum of adult Wistar rats and it was also observed that ascorbic acid prevents or minimize lead-induced cellular damage in the cerebellum of adult Wistar rats.

  10. EFFECTS OF ASCORBIC ACID AND ACETYLSALICYLIC ACID SUPPLEMENTATION ON THE PERFORMANCE OF BROILER CHICKS EXPOSED TO HEAT STRESS

    OpenAIRE

    Anwar, Bilal; Khan, Shakil Akhtar; Aslam, Asim; MAQBOOL, Azhar; Khan, Kashif Aziz

    2004-01-01

    A total of 100, day-old broiler chicks were randomly divided into 5 equal groups and kept under elevated temperature (93-97°F) to see the effect of ascorbic acid and acetylsalicylic acid on the feed conversion ratio (FCR), immune status and ratio of weight of bursa, thymus and spleen to body weight. Heat stress increased the FCR but decreased the immune response and ratio of bursa, thymus and spleen to body weight of the birds. Ascorbic acid and acetylsalicylic acid supplementation during hea...

  11. EFFECTS OF ASCORBIC ACID AND ACETYLSALICYLIC ACID SUPPLEMENTATION ON THE PERFORMANCE OF BROILER CHICKS EXPOSED TO HEAT STRESS

    OpenAIRE

    B. Anwar, S. A. Khan, A. Aslam, A. Maqbool1 and K. A. Khan

    2004-01-01

    A total of 100, day-old broiler chicks were randomly divided into 5 equal groups and kept under elevated temperature (93-97oF) to see the effect of ascorbic acid and acetylsalicylic acid on the feed conversion ratio (FCR), immune status and ratio of weight of bursa, thymus and spleen to body weight. Heat stress increased the FCR but decreased the immune response and ratio of bursa, thymus and spleen to body weight of the birds. Ascorbic acid and acetylsalicylic acid supplementation during hea...

  12. Modulating Effect of Ascorbic Acid on Transport-Induced Immunosuppression in Goats

    OpenAIRE

    Ndazo Salka Minka; Joseph Olusegun Ayo

    2011-01-01

    The effect of 12?h road transportation on some basic blood cells and the modulating role of ascorbic acid were investigated in 40 adult Red Sokoto goats during the hot dry season. The animals were divided into two groups, GI (experimental; n = 20) and GII (control; n = 20). Group 1 was administered with ascorbic acid (AA) per os at a dosage rate of 100?mg/kg body weight, while GII was given 10?mL of sterile water per goat. Forty minutes after the administration and loading, the goats were tra...

  13. Comparative analysis of ascorbic acid in human milk and infant formula using varied milk delivery systems

    OpenAIRE

    Dickton Darby; Brewer Paul; Rogers Kristy; Francis Jimi; Pardini Ron

    2008-01-01

    Abstract Background The expression of human milk for later use is on the rise. Bottle systems are used to deliver the expressed milk. Research has shown that storage of both human milk and artificial baby milk, or infant formula, leads to a loss of ascorbic acid (commonly called Vitamin C). As milk is removed from the bottle during feeding and replaced by ambient air, it is unknown if loss of ascorbic acid occurs during the course of a feeding. The purpose of this study is to investigate the ...

  14. The Effect of Ascorbic Acid on Cadmium Exposure in the Gills of Puntius altus

    Directory of Open Access Journals (Sweden)

    Piya Kosai

    2007-01-01

    Full Text Available The effects of cadmium and ascorbic acid on the gills of Red-tailed tinfoil barb (Puntius altus were compared using light and scanning electron microscopic study for the period 24, 48, 72 and 96 h. The main alterations in the cadmium treated group were edema, filament cell proliferation, lamellar cell hyperplasia, lamellar fusion, epithelial lifting and aneurysm. These changes occurred predominantly in the 96 h treatment. In the combination of cadmium and ascorbic acid treated group, they showed similar alterations as those observed in the cadmium treated alone group but they were less severe.

  15. Signal transduction pathway for L-ascorbic acid- and L-ascorbic acid 2-glucoside-induced DNA synthesis and cell proliferation in primary cultures of adult rat hepatocytes.

    Science.gov (United States)

    Moteki, Hajime; Shimamura, Yuya; Kimura, Mitsutoshi; Ogihara, Masahiko

    2012-05-15

    We examined the effects of L-ascorbic acid and its analogues on DNA synthesis and cell proliferation. We also investigated the signal transduction pathways involved in the induction of mitogenesis by L-ascorbic acid and its analogues using primary cultures of adult rat hepatocytes. Following a 4-h serum-free cultivation, both L-ascorbic acid and its stable analogue, L-ascorbic acid 2-glucoside, time- and dose-dependently stimulated hepatocyte DNA synthesis and cell proliferation, with EC?? values of 6.46×10?? M and 3.34×10?? M, respectively. Dehydroascorbic acid (10?? M-10?? M) weakly stimulated hepatocyte mitogenesis, whereas isoascorbic acid (10?? M-10?? M) had no effect. Hepatocyte mitogenesis induced by L-ascorbic acid or L-ascorbic acid 2-glucoside was dose-dependently abolished by treatment with monoclonal antibodies against insulin-like growth factor (IGF)-I receptor, but not by treatment with monoclonal antibodies against insulin receptor or IGF-II receptor. Western blot analysis showed that both L-ascorbic acid and L-ascorbic acid 2-glucoside significantly stimulated IFG-I receptor tyrosine kinase activity within 3 min, and mitogen-activated protein (MAP) kinase activity within 5 min. These results demonstrate that both L-ascorbic acid and L-ascorbic acid 2-glucoside induce DNA synthesis and cell proliferation in primary cultures of adult rat hepatocytes by interacting with the IGF-I receptor site and by activating the receptor tyrosine kinase/MAP kinase pathway. PMID:22429571

  16. Plasma and aqueous humur ascorbic acid levels in people with cataract from diverse geographical regions of Nepal.

    Science.gov (United States)

    Badhu, B; Baral, N; Lamsal, M; Das, H; Dhital Badhu, A

    2007-05-01

    Ascorbic acid in aqueous humor of the eye has a role as an antioxidant in delaying cataract formation. In a cross-sectional comparative study, ascorbic acid levels from aqueous humor and venous blood obtained from patients with cataracts in mountainous regions (1,300-2,000 meters) and subtropical lowlands (<100 meters) of Nepal were measured spectrophotometrically with the objective of comparing the levels of aqueous humor ascorbic acid in patients with cataracts from these two diverse geographical regions. Of 131 patients included in the study, 59 were from the mountainous region of Nepal (Group A) and 72 were from the subtropical lowlands (Group B). The mean (+/- SD) plasma ascorbic acid level (mg%) of the subjects in Group A was 0.65 (+/- 0.20) and Group B was 0.85 (+/- 0.31). The aqueous ascorbic acid levels ranged from 12-28 mg % (mean +/-SD = 17.5+/-4.52) and 14-50 mg % (mean +/-SD =23.47+/-8.66) in Groups A and B, respectively. The difference of the plasma and aqueous humor ascorbic acid levels between the two groups was statistically significant (p<0.01). The plasma and aqueous humor ascorbic acid levels in the people with cataracts from the mountainous region of Nepal were significantly lower than those from subtropical lowlands. This may be because of the effect of high altitude and ultraviolet rays on ascorbic acid metabolism. PMID:17877237

  17. Fabrication of multiwalled carbon nanotubes/polyaniline modified Au electrode for ascorbic acid determination.

    Science.gov (United States)

    Chauhan, Nidhi; Narang, Jagriti; Pundir, C S

    2011-05-01

    An ascorbate oxidase (AsOx) (E.C.1.10.3.3) purified from Lagenaria siceraria fruit was immobilized covalently onto a carboxylated multiwalled carbon nanotubes and polyaniline (c-MWCNT/PANI) layer electrochemically deposited on the surface of an Au electrode. The diffusion coefficient of ascorbic acid was determined as 3.05 × 10(-4) cm(2) s(-1). The behavior of different electrolytes on electro-deposition was also studied. An ascorbate biosensor was fabricated using a AsOx/c-MWCNT/PANI/Au electrode as a working electrode, Ag/AgCl (3 M/saturated KCl) as standard and Pt wire as an auxiliary electrode connected through a potentiostat. Linear range, response time and detection limit were 2-206 ?M, 2 s and 0.9 ?M respectively. The biosensor showed optimum response at pH 5.8 and in a broader temperature range (30-45 °C), when polarized at +0.6 V. The biosensor was employed for determination of ascorbic acid level in sera, fruit juices and vitamin C tablets. The sensor was evaluated with 91% recovery of added ascorbic acid in sera and 6.5% and 11.4% within and between batch coefficients of variation respectively for five serum samples. There was a good correlation (r = 0.98) between fruit juice ascorbic acid values by the standard 2,6-dichlorophenolindophenol (DCPIP) method and the present method. The enzyme electrode was used 200 times over a period of two months, when stored at 4 °C. The biosensor has advantages over earlier enzyme sensors in that it has no leakage of enzyme, due to the covalent coupling of enzyme with the support, lower response time, wider working range, higher storage stability and no interference by serum substances. PMID:21416096

  18. THE INFLUENCE OF SOME STORAGE CONDITIONS UPON ASCORBIC ACID CONTENT IN WHITE AND RED CABBAGE

    Directory of Open Access Journals (Sweden)

    Marcel Avramiuc

    2013-12-01

    Full Text Available In this work it has searched the influence of storage conditions upon ascorbic acid content in cabbage. Theascorbic acid content and pH evolution for 16 weeks has been carried out using, as biological material, cabbage samplesfrom two varieties: white cabbage (Brassica oleracea var. capitata L. f. alba DC. and red cabbage (Brassica oleracea var.capitata L. f. rubra (L. Thell. The cabbage samples were kept in containers of glass and wood, constituting, for eachsample, variants of experiences, in the presence and in the absence of oxygen, at following thermal thresholds: 4°C, 8°Cand 15°C. The ascorbic acid content of cabbages was determined through a method based on reduction by the ascorbicacid of 2.6-Dichlorphenol-indophenol (2.6-DCFIF to the corresponding leucoderivate. The investigations have beencarried out on freshly harvested material (week 0 and then every two weeks, for a total of 16 weeks. Compared to freshharvested cabbage, at the end of the analysed interval (after 16 weeks of storage, the ascorbic acid content has registereddifferent rates of diminution in the both varieties, depending on storage temperature, on storage length, and on variety.The ascorbic acid in white cabbage has registered losses, compared to red variety, so much the bigger as the temperaturewas higher and the storage duration was longer.

  19. Effect of Ascorbic Acid and Acetylsalicylic Acid Supplementation on Performance of Broiler Chicks Exposed to Heat Stress

    OpenAIRE

    Shamoon Naseem; M. Younus; Bilal Anwar; Aamir Ghafoor; Asim Aslam; Akhter, S

    2005-01-01

    A total of 100, day-old broiler chickens were randomly divided into 5 groups and kept under elevated temperature (34-36oC) to see the effect of ascorbic acid and acetylsalicylic acid (Sb-Asper-C, a commercial product) on the feed conversion ratio (FCR), immune status and ratio of weight of bursa, thymus and spleen to body weight. Heat stress increased the FCR but decreased the immune response and ratio of bursa, thymus and spleen to body weight of the birds. Ascorbic acid and acetylsal...

  20. O-Anisidine as Indicator in Titrimetric Determination of Ascorbic Acid and Isonicotinic Acid Hydrazide in Pharmaceutical Formulations

    Directory of Open Access Journals (Sweden)

    B.S.A.Andrews

    2010-10-01

    Full Text Available Inspite of the beautiful red coloured oxidized product of O-anisidine, the studies on its application in analytical techniques are scanty. So, authors have taken up the investigation on the utility of O-anisidine as a new Analytical reagent in the bromatometric-Indicator reaction. The detailed reaction on the potassium bromate and OAnisidine has enabled the authors to utilize O-Anisidine in titration of Ascorbic Acid and Isonicitonic Acid Hydrazide. Suitable conditions has been established with different acids viz., hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid to give sharp colour change at the equivalence point. The present method has been applied for the estimation of Ascorbic acid and also Isonicitonic Acid Hydrazide in pharmaceutical formulations and results obtained are in good agreement with the values obtained by standard methods

  1. CAPSAICIN AND ASCORBIC ACID VARIABILITY IN CHILLI AND PAPRIKA CULTIVARS AS REVEALED BY HPLC ANALYSIS

    Directory of Open Access Journals (Sweden)

    Samuel Tilahun

    2013-08-01

    Full Text Available Capsaicin and ascorbic acid contents of seven Indian peppers varieties/accessions from Capsicum annuum (CA 97, CCH, K1, KTPL19, Arka Abhir and Bayadagi Kaddi and C. frutescens (CF1 species were determined using High Performance Liquid Chromatography (HPLC. Based on their pungency value, all the chilli accession/varieties (CA 97, CCH, K1, and CF 1 were classified as highly pungent peppers. The accession CF1 showed the highest concentration of capsaicin (445mg 100g -1 DW with corresponding pungency value of 71,200 SHUs and Arka Abhir variety showed the lowest capsaicin concentration (29mg 100g -1 DW with 4,672 SHUs of pungency value. Similarly, Bayadaggi kaddi variety showed the highest ascorbic acid content (189 mg/100 FW and the accession CA 97 showed the lowest ascorbic acid contents (55.3 mg/100 FW. The variability in capsaicin and ascorbic acid content presented in the pepper germplasm can be exploited for breeding cultivars with improved nutritional qualities. Moreover, CF1and Bayadagi kaddi can be used as a potential source for capsaicin and vitamin C, respectively.

  2. INFLUENCES OF THIAMINE AND/OR ASCORBIC ACID ON LEAD INTOXICATION

    Directory of Open Access Journals (Sweden)

    M. Ghazi-Khansari

    1996-07-01

    Full Text Available The effects of thiamine, ascorbic acid ami their combination an workers who are continuously exposal to lead has been investigated. In this study 60 persons in a Battery industry was selected and divided into four equal groups. Group I received placebo, group II thiamine (300 mg, group III ascorbic acid (250 mg anil group IV thiamine (300 mg plus ascorbic acid (250 mg three times a day (Orally. At beginning of the study and after one month of above drug regimen; blood, urine and a questionnaire about their clinical signs were examined. 'there were no significant differences between blood anil urine lead level in all groups after treatment. Zinc protoporphyrin (zpp level showed a significant reduction in ascorbic acid treated group (group III as compared to pretreatment. Clinical manifestation improved in the group that received both vitamins (group IV. However, from a clinical stand point, it appears the usage of these vitamins may have a beneficial effects in lead occupational exposure.

  3. A method for the determination of ascorbic acid using the iron(II)-pyridine-dimethylglyoxime complex

    Energy Technology Data Exchange (ETDEWEB)

    Arya, S. P.; Mahajan, M. [Haryana, Kurukshetra Univ. (India). Dept. of Chemistry

    1998-05-01

    A simple and rapid spectrophotometric method for the determination of ascorbic acid is proposed. Ascorbic acid reduces iron (III) to iron (II) which forms a red colored complex with dimethylglyoxime in the presence of pyridine. The absorbance of the resulting solution is measured at 514 nm and a linear relationship between absorbance and concentration of ascorbic acid is observed up to 14 {mu}g ml{sup -1}. Studies on the interference of substances usually associated with ascorbic acid have been carried out and the applicability of the method has been tested by analysing pharmaceutical preparations of vitamin C. [Italiano] Si propone un rapido e semplice metodo spettrofotometrico per la determinazione dell`acido ascorbico. L`acido ascorbico riduce il ferro(III) a ferro(II) che forma con la dimetilgliossima, in presenza di piridina, un complesso colorato in rosso. L`assorbanza della soluzione risultante e` misurata a 514 nm e si ottiene una relazione lineare tra assorbanza e concentrazione dell`acido ascorbico fino a 14 {mu}g ml{sup -1}. Si sono condotti studi sugli interferenti usualmente associati all`acido ascorbico ed e` stata valutata l`applicabilita` del metodo all`analisi di preparati farmaceutici di vitamina C.

  4. Factors affecting plasma Contents of thiamine and Ascorbic acid in Camels (Camelus dromedarius

    Directory of Open Access Journals (Sweden)

    Mohamed, H. E.

    2006-01-01

    Full Text Available The study was designed to investigate the effect of age, breed, sex, and breeding season on thiamine and ascorbic acid status (AA in camels (Camelus dromedarius. A total of 375 camels were sampled over a one-year field survey in Butana area, Central Sudan. No effect of sex on thiamine and ascorbic acid levels was observed. The breeding male and female camels showed higher status of plasma thiamine and lower ascorbic acid as compared to non-breeding camels. Thiamine plasma contents showed variation with respect to age. The thiamine plasma levels for neonate, yearling, and adult were 59.94.4, 70.58.9 and 88.96.7 g/L, respectively. The corresponding figures for AA were 6.21.0, 4.90.9, and 4.50.8 mg/L, respectively. The Arabi showed higher ascorbic acid (5.91.0 than Anafi (4.20.9 mg/L. However, no significant breed variation for thiamine status was indicated.

  5. CAPSAICIN AND ASCORBIC ACID VARIABILITY IN CHILLI AND PAPRIKA CULTIVARS AS REVEALED BY HPLC ANALYSIS

    Directory of Open Access Journals (Sweden)

    Samuel Tilahun

    2013-10-01

    Full Text Available Capsaicin and ascorbic acid contents of seven Indian peppers varieties/accessions from Capsicum annuum (CA 97, CCH, K1, KTPL19, Arka Abhir and Bayadagi Kaddi and C. frutescens (CF1 species were determined using High Performance Liquid Chromatography (HPLC. Based on their pungency value, all the chilli accession/varieties (CA 97, CCH, K1, and CF 1 were classified as highly pungent peppers. The accession CF1 showed the highest concentration of capsaicin (445mg 100g -1 DW with corresponding pungency value of 71,200 SHUs and Arka Abhir variety showed the lowest capsaicin concentration (29mg 100g -1 DW with 4,672 SHUs of pungency value. Similarly, Bayadaggi kaddi variety showed the highest ascorbic acid content (189 mg/100 FW and the accession CA 97 showed the lowest ascorbic acid contents (55.3 mg/100 FW. The variability in capsaicin and ascorbic acid content presented in the pepper germplasm can be exploited for breeding cultivars with improved nutritional qualities. Moreover, CF1and Bayadagi kaddi can be used as a potential source for capsaicin and vitamin C, respectively.

  6. Ascorbic acid, cognitive function, and Alzheimer’s disease: a current review and future direction

    OpenAIRE

    Bowman, Gene L.

    2012-01-01

    This narrative review appraises the human and animal studies implicating ascorbic acid (AA) in normal cognitive function and Alzheimer’s disease. A research framework for how nutrition affects brain aging is proposed with emphasis on AA intake, status, metabolism, and transport into brain tissue. A final synopsis highlights areas for future research regarding AA nourishment and healthy brain aging.

  7. Exogenous application of ascorbic acid stimulates growth and photosynthesis of wheat (Triticum aestivum L. under drought

    Directory of Open Access Journals (Sweden)

    Samina Malik and Muhammad Ashraf

    2012-05-01

    Full Text Available Drought causes considerable reduction in plant growth. A hydroponic experiment was conducted to appraise the potential role of exogenously applied ascorbic acid in alleviating the effect of drought on wheat. Two contrasting wheat genotypes, a drought tolerant cultivar Chakwal-86 and a drought sensitive strain 6544-6 were used in the study. Drought was induced by dissolving 20% Polyethylene glycol (PEG8000 in the nutrient solution producing -0.6MPa osmotic stress. Drought caused a significant decrease in chlorophyll pigments and net photosynthesis resulting in growth reduction of both wheat genotypes. However, this decrease was more severe in the genotype 6544-6 compared to Chakwal-86. Ascorbic acid (AsA was applied through rooting medium, as a foliar spray and seed soaking treatment. Ascorbic acid treated seedlings of both genotypes maintained higher chlorophyll contents, net photosynthesis and growth compared to the non-treated plants. Of the three different modes of ascorbic acid application, rooting medium was more effective in alleviating the adversities of drought in wheat. `

  8. Elimination of ascorbic acid after high-dose infusion in prostate cancer patients

    DEFF Research Database (Denmark)

    Nielsen, Torben Kjær; Højgaard, Martin; Andersen, Jon Thor Trærup; Poulsen, Henrik Enghusen; Lykkesfeldt, Jens; Mikines, Kari Joensen

    2015-01-01

    Treatment with high-dose intravenous (IV) ascorbic acid (AA) is used in complementary and alternative medicine for various conditions including cancer. Cytotoxicity to cancer cell lines has been observed with millimolar concentrations of AA. Little is known about the pharmacokinetics of high dose...

  9. Effect of preservation method and storage condition on ascorbic acid loss in beverages

    Directory of Open Access Journals (Sweden)

    Jokanovi? Marija R.

    2009-01-01

    Full Text Available Global market is flooded with vitamin-enriched foods, mainly beverages. Major vitamins for enriching beverages are the antioxidant vitamins A, C and E. Ascorbic acid is readily oxidized and lost during storage of the beverages, at rates depending on the conditions of storage. This fact is of great importance for the consumer who must know how to store beverages and when to consume them in order to get the maximum benefit of added vitamin C. The objective of this paper was to determine the amount of ascorbic acid lost in beverages applying different preservation methods and storage condition. Beverage was made in laboratory conditions with synthetic L-ascorbic acid added according to the national legislations. After 30 days of storage at 4-8oC ascorbic acid overall loss was from 81.01% to 90.27% in thermally pasteurized samples and from 97.83 % to almost complete loss in samples preserved with sodium benzoate.

  10. Developmental response of the beneficial predator Podisus maculiventris to change in dietary ascorbic acid concentration

    Science.gov (United States)

    We report here the effects of ascorbic acid concentrations (0.07, 0.3, 3.0 and 30.0 g/L) in artificial diets on growth rates, adult weights, fecundity and survival of the predatory stink bug, Podisus maculiventris. Overall, a dietary level of 3.0 g/L gave the shortest developmental times over both ...

  11. NITROGEN DIOXIDE EXPOSURE AND LUNG ANTIOXIDANTS IN ASCORBIC ACID-DEFICIENT GUINEA PIGS

    Science.gov (United States)

    The authors have previously found that ascorbic acid (AA) deficiency in guinea pigs enhances the pulmonary toxicity of nitrogen dioxide (NO2). The present study showed that exposure to NO2 (4.8 ppm, 3 hr) significantly increased lung lavage fluid protein (a sensitive indicator of...

  12. A colorimetric probe for ascorbic acid based on copper-gold nanoparticles in electrospun nylon

    International Nuclear Information System (INIS)

    We report on a colorimetric probe based on copper-gold alloy nanoparticles (NPs). The probe is capable of selectively detecting ascorbic acid (AA) as a result of the distance-dependent colour change of the nanoparticles immobilized in an electrospun nylon-6 nanofiber. The resulting white nanofibres undergo a colour change to blue as a result of the aggregation of the NPs induced by AA in the pH range 2–7. The probe is selective for AA even in the presence of dopamine, uric acid, saccharides, amino acids and certain organic acids. It covers the 1.76 x10?2 mg L?1 to 1.76 x105 mg L?1 concentration range, and exhibits a limit of detection of 1.76 x10?2 mg L?1 based on visual detection. Its application was demonstrated by the determination of ascorbic acid in fruit juices, urine, serum, and vitamin C tablets. (author)

  13. Relevance of DNA repair pathways on ascorbic acid effects on Echerichia Coli K-12 cells

    International Nuclear Information System (INIS)

    Inactivation kinetics were performed with repair proficient and deficient Escherichia coli K-12 cells treated with oxidized solutions of ascorbic acid. The repair pathways controlled by the recA and uvrA gene products are essential for cell survival to the treatment. However, SOS chromotest result indicates that the SOS functions are only induced at high and toxic concentrations of the drug. Moreover, single strand breaks in DNA from treated cells are detected, demonstrating genome damage promoted by oxidized solutions of ascorbate. (M.A.C.)

  14. Ascorbic acid supplementation diminishes microparticle elevations and neutrophil activation following SCUBA diving.

    Science.gov (United States)

    Yang, Ming; Barak, Otto F; Dujic, Zeljko; Madden, Dennis; Bhopale, Veena M; Bhullar, Jasjeet; Thom, Stephen R

    2015-08-15

    Predicated on evidence that diving-related microparticle generation is an oxidative stress response, this study investigated the role that oxygen plays in augmenting production of annexin V-positive microparticles associated with open-water SCUBA diving and whether elevations can be abrogated by ascorbic acid. Following a cross-over study design, 14 male subjects ingested placebo and 2-3 wk later ascorbic acid (2 g) daily for 6 days prior to performing either a 47-min dive to 18 m of sea water while breathing air (?222 kPa N2/59 kPa O2) or breathing a mixture of 60% O2/balance N2 from a tight-fitting face mask at atmospheric pressure for 47 min (?40 kPa N2/59 kPa O2). Within 30 min after the 18-m dive in the placebo group, neutrophil activation, and platelet-neutrophil interactions occurred, and the total number of microparticles, as well as subgroups bearing CD66b, CD41, CD31, CD142 proteins or nitrotyrosine, increased approximately twofold. No significant elevations occurred among divers after ingesting ascorbic acid, nor were elevations identified in either group after breathing 60% O2. Ascorbic acid had no significant effect on post-dive intravascular bubble production quantified by transthoracic echocardiography. We conclude that high-pressure nitrogen plays a key role in neutrophil and microparticle-associated changes with diving and that responses can be abrogated by dietary ascorbic acid supplementation. PMID:26084697

  15. Comparison of radioprotective effects of caffeine and ascorbic acid in male mice

    International Nuclear Information System (INIS)

    The oxygen effect in radiation biology is well known. Since oxygen enhances radiation-induced biological damage, antioxidants should be radioprotectors. Ascorbic acid (vitamin C) or caffeine is an essential component in the diet of humans and a small range of other mammals. Radioprotective effects of vitamin C have been demonstrated in certain cells and animals, which would result from scavenging free radicals. Caffeine is the main psychoactive ingredient of coffee, tea, even coke with a high frequency of concurrent use in humans. Caffeine has been recently reported as a scavenger of hydroxyl radical in millimolar levels and a potently radioprotector in a chronically exposed rodent. This study investigates functional radioprotection of caffeine and ascorbic acid against gamma irradiation in male mice. Eight-week-old male C57BL/6N mice were irradiated with 6.5 Gy. A caffeine treated group was administered with 80 mg/kg body weight by i.p injection, a single exposure 1 hour before irradiation. Ascorbic acid was administered 330 mg/liter in drinking water through all the experimental period. The remaining mice were kept as sham controls. After collecting a serum from the experimental mice 6 hr after irradiation, qualitative analysis of testosterone was performed by means of radioimmunoassay (RIA). For histological investigation, testes were removed 1 week after irradiation and fixed in NBF. Fixed testes were processed for paraffin sections and stained by H-E. The circulating testosterone significantly decreased in all irradiated groups. The harmful effect of radiation on the body and organ weight and the appearance of semiferous tubules were significantly improved in the caffeine - or ascorbic acid-treated group. In conclusion, caffeine and ascorbic acid protected spermatogenesis from impairment against gamma radiation, acting as a radioprotector

  16. Norepinephrine-modified glassy carbon electrode for the simultaneous determination of ascorbic acid and uric acid

    International Nuclear Information System (INIS)

    The oxidation of norepinephrine (NE) on a preactivated glassy carbon electrode leads to the formation of a deposited layer of about 4.2 x 10-10 mol cm-2 at the surface of the electrode. The electron transfer rate constant, k s, and charge transfer coefficient, ?, for electron transfer between the electrode and immobilized NE film were calculated as 44 s-1 and 0.46, respectively. The NE-modified glassy carbon electrode exhibited good electrocatalytic properties towards ascorbic acid (AA) oxidation in phosphate buffer (pH 7.0) with an overpotential of about 475 mV lower than that of the bare electrode. The electrocatalytic response was evaluated by cyclic voltammetry, chronoamperometry, amperometry and rotating disk voltammetry. The overall number of electrons involved in the catalytic oxidation of AA and the number of electrons involved in the rate-determining step are 2 and 1, respectively. The rate constant for the catalytic oxidation of AA was evaluated by RDE voltammetry and an average value of k h was found to be 8.42 x 103 M-1 s-1. Amperometric determination of AA in stirred solution exhibits a linear range of 2.0-1300.0 ?M (correlation coefficient 0.9999) and a detection limit of 0.076 ?M. The precision of amperometry was found to be 1.9% for replicate determination of a 49.0 ?M solution of AA (n = 6). In differential pulse voltammetric measurements, the NE-modified glassy carbon electrode can separate the AA and uric acid (UA) signals. Ascorbic acid oxidizes at more negative potential than UA. Also, the simultaneous determination of UA and AA is achieved at the NE-modified electrode

  17. Antioxidative activity of citric and ascorbic acids and their preventive effect on lipid oxidation in frozen persian sturgeon fillets

    Scientific Electronic Library Online (English)

    H., Rostamzad; B., Shabanpour; M., Kashaninejad; A., Shabani.

    2011-04-01

    Full Text Available Persian sturgeon (Acipenser persicus) fillets were soaked in Citric acid, Ascorbic acid and combination of Citric and Ascorbic acid solutions and then were stored at frozen conditions (-18 °C) up to 6 months. During storage, some general chemical analysis such as free fatty acids, primary and second [...] ary oxidation products and sensory analysis were measured in order to study rancidity development. Results showed that antioxidant treatments had lower (P

  18. Ascorbic Acid Rejection Characteristics of Modified Platinum Electrodes: A Shelf Life Investigation

    Directory of Open Access Journals (Sweden)

    Andrea M. Wynne

    2015-04-01

    Full Text Available Ascorbic acid (AA is the principle interferent present in brain extracellular fluid that can inhibit the ability of electrochemical sensors to selectively detect a particular analyte of interest. Considerable efforts have been made in recent times to develop highly selective membrane coatings to counteract the drawbacks associated with AA interference during in vivo monitoring. The primary objective of the work described within was to investigate the long term effect of storing such selective membranes, i.e., Nafion® and Poly-o-phenylenediamine (PPD under different conditions and how exposing them to repeated calibration protocols compromises the membranes ability to reject AA. Four different modified platinum (Pt electrodes, Pt-PPD, Pt-Nafion® (5/2, Pt-Nafion® (1/2-PPD, and Pt-Nafion® (2/1-PPD, stored at 4 °C demonstrated deterioration of the polymers integrity when exposed to repeated calibrations. On the contrary, exposing the same four electrode types to single calibrations confirmed excellent retention of AA rejection characteristics. Pt-PPD electrodes were then exposed to varying storage conditions and calibrated against AA on day 1, day 56 and day 168. Storing the Pt-PPD electrodes at 4 °C/N2 saturated glass container demonstrated retention of AA rejection characteristics after day 168. These results have clearly elucidated the optimum storage conditions for Pt-Nafion® and Pt-PPD modified electrodes.

  19. THE INFLUENCE OF SOME STORAGE CONDITIONS UPON ASCORBIC ACID CONTENT IN WHITE AND RED CABBAGE

    OpenAIRE

    Marcel Avramiuc

    2013-01-01

    In this work it has searched the influence of storage conditions upon ascorbic acid content in cabbage. Theascorbic acid content and pH evolution for 16 weeks has been carried out using, as biological material, cabbage samplesfrom two varieties: white cabbage (Brassica oleracea var. capitata L. f. alba DC.) and red cabbage (Brassica oleracea var.capitata L. f. rubra (L.) Thell). The cabbage samples were kept in containers of glass and wood, constituting, for eachsample, variants of experience...

  20. Betalain, Acid Ascorbic, Phenolic Contents and Antioxidant Properties of Purple, Red, Yellow and White Cactus Pears

    OpenAIRE

    Leonardo Martinez-Cardenas; Carmen Valadez-Vega; Nelly Cruz-Cansino; Raquel Cariño-Cortés; Juan Diego García-Paredes; Eduardo Madrigal-Santillán; María Teresa Sumaya-Martínez; Sandra Cruz-Jaime; Ernesto Alanís-García

    2011-01-01

    Commercialization of cactus pears based on their antioxidant properties can generate competitive advantages, and these can turn into business opportunities and the development of new products and a high-value ingredient for the food industry. This work evaluated the antioxidant activities (1,1-diphenyl-2-picrylhydrazyl radical-scavenging, protection against oxidation of a ?-carotene-linoleic acid emulsion, and iron (II) chelation), the content of total phenolic compounds, ascorbic acid, betac...

  1. Glycation by ascorbic acid oxidation products leads to the aggregation of lens proteins

    OpenAIRE

    Linetsky, Mikhail; Shipova, Ekaterina; CHENG, RONGZHU; Ortwerth, Beryl J.

    2008-01-01

    Previous studies from this laboratory have shown that there are striking similarities between the yellow chromophores, fluorophores and modified amino acids released by proteolytic digestion from calf lens proteins ascorbylated in vitro and their counterparts isolated from aged and cataractous lens proteins. The studies reported in this communication were conducted to further investigate whether ascorbic acid-mediated modification of lens proteins could lead to the formation of lens protein a...

  2. Role of ascorbic acid and ? tocopherol in alleviating salinity stress on flax plant (Linum usitatissimum L.

    Directory of Open Access Journals (Sweden)

    Mervat Sh. Sadak

    2014-03-01

    Full Text Available Salinity is one of the environmental challenges in the world affecting on several physiological processes and the most limiting factor of plant productivity and quality. Two pot experiments were conducted at the wire house of National Research Centre, Cairo, Egypt during two successive seasons of 2010/2011 and 2011/2012 to assess the efficiency of two antioxidant vitamins (ascorbic acid at 1.13 and 2.27 mM or ? tocopherol at 0.46 and 0.93 mM and/or salinity stress at (0.0, 3.08, 6.16, 9.23 ds/m on photosynthetic pigments, protein, carbohydrate, minerals, oil contents and yield as well as fatty acids composition of the yielded oils of three flax cultivars (Sakha 3, Giza 8 and Ariane. The data revealed that salinity stress caused significant and gradual decreases in total photosynthetic pigments, polysaccharides, total carbohydrates, total proteins and the uptake of Mg, K, Ca and P in the leaves of three flax cultivars with increasing salinity levels (3.08, 6.16, 9.23 ds/m. Otherwise, significant and gradual increase appeared in both Na and Cl. Ascorbic acid and ? tocopherol at different concentrations caused significant increases in photosynthetic pigments, total carbohydrates and protein contents in the leaves of flax plants irrigated either with tap water or saline solution as compared with their corresponding controls. Exogenous application of ascorbic and ? tocopherol at different concentrations exhibited decreases in Na and Cl whereas increases appeared in Mg, K, Ca and P relative to their corresponding control. Ascorbic acid (1.13 and 2.27 mM and ? tocopherol (0.46 and 0.93 mM caused marked increases in yield and yield attributes of three flax cultivars either in plants irrigated with tap water or saline solution as compared to corresponding control. Ascorbic acid effects were more pronounced than ? tocopherol effects. In addition, the higher level of two vitamins was more pronounced than the lower level. Regarding plants irrigated with tap water, it was noted that ascorbic acid at 2.27 mM caused significant increase in oil content by 19.75 % in Giza 8 whereas ? tocopherpl at 0.93 mM caused significant increase by 14.83% in Sakha 3 and 13.70% in Ariane. Regarding plants irrigated with saline solution (9.23 ds/m, it was found that ? tocopherol at 0.93 mM caused significant increase in oil % by 30.84 %, 9.66 % and 35.62 % in Sakha 3, Giza 8 and Ariane cv. respectively. Responses of three flax cultivars to salt stress were more or less similar; since salinity stress caused marked increases in total saturated fatty acids accompanied by decreases in total unsaturated fatty acids as salinity levels increased. Myristic acid (C14:0 and oleic acid (C18:1 were the most affected saturated and unsaturated fatty acids in response to different salinity levels. The effect of ascorbic acid at 2.27 mM and tocopherol at 0.93 mM were found to be contrary to that of salinity as marked increases appeared in unsaturated fatty acids as compared with control plants. It could be concluded that foliar application of ascorbic acid and ? tocopherol could play an enhancement role and alleviate the harmful effect of salinity stress on many metabolic and physiological processes of three flax cultivars that reflected in increasing seed yield quality and quantity.

  3. A Combination of Pre- and Post-Exposure Ascorbic Acid Rescues Mice from Radiation-Induced Lethal Gastrointestinal Damage

    Directory of Open Access Journals (Sweden)

    Yukihiro Takahashi

    2013-09-01

    Full Text Available The development of an effective therapy for radiation-induced gastrointestinal damage is important, because it is currently a major complication of treatment and there are few effective therapies available. Although we have recently demonstrated that pretreatment with ascorbic acid attenuates lethal gastrointestinal damage in irradiated mice, more than half of mice eventually died, thus indicating that better approach was needed. We then investigated a more effective therapy for radiation-induced gastrointestinal damage. Mice receiving abdominal radiation at 13 Gy were orally administered ascorbic acid (250 mg/kg/day for three days before radiation (pretreatment, one shot of engulfment (250 mg/kg at 8 h before radiation, or were administered the agent for seven days after radiation (post-treatment. None of the control mice survived the abdominal radiation at 13 Gy due to severe gastrointestinal damage (without bone marrow damage. Neither pretreatment with ascorbic acid (20% survival, engulfment (20%, nor post-treatment (0% was effective in irradiated mice. However, combination therapy using ascorbic acid, including pretreatment, engulfment and post-treatment, rescued all of the mice from lethal abdominal radiation, and was accompanied by remarkable improvements in the gastrointestinal damage (100% survival. Omitting post-treatment from the combination therapy with ascorbic acid markedly reduced the mouse survival (20% survival, suggesting the importance of post-treatment with ascorbic acid. Combination therapy with ascorbic acid may be a potent therapeutic tool for radiation-induced gastrointestinal damage.

  4. Ascorbic Acid and α-Tocopherol Minimize Salt-Induced Wheat Leaf Senescence

    Directory of Open Access Journals (Sweden)

    Farouk S.

    2011-09-01

    Full Text Available BackgroundLeaf senescence is an oxidative process, and most of the catabolic events involved in senescence are propagated irreversibly once initiated. ResultsSalinity hastened the senescence of wheat flag leaves, decreased the concentrations of chlorophyll, total carotenoids, ascorbic acid, total phenol, calcium, potassium, magnesium, K+/Na+ ratio and soluble proteins, as well as the activities of catalase and peroxidase. Conversely, salinity increased sodium, chloride, and the chlorophylla:b ratio, as well as membrane permeability, hydrogen peroxide, and malondialdehyde synthesis. Both antioxidants application reduced the hydrogen peroxide accumulation, lipid peroxidation, membrane permeability, sodium and chloride content over control plants. The antioxidants enzyme activities were significantly increased by antioxidant spray. Enhanced accumulation of ascorbate, phenol, carotenoids, calcium, potassium and magnesium was seen in antioxidants-sprayed plants compared with control plants at 65 days after sowing. Under moderate and sever salinity levels application of both antioxidants alleviated the harmful effects of salinity on leaf senescence related parameter. The higher levels of antioxidants and low level of H2O2 in flag leaf may be the prerequisite for delayed leaf senescence in antioxidants-sprayed plants. ConclusionsIt can be concluded that ascorbic acid-sprayed plants can postpone the leaf senescence by peroxide/phenolic/ascorbate system which is involved in scavenging the ROS produced during leaf senescence.

  5. The application of conducting polymer nanoparticle electrodes to the sensing of ascorbic acid.

    Science.gov (United States)

    Ambrosi, Adriano; Morrin, Aoife; Smyth, Malcolm R; Killard, Anthony J

    2008-02-18

    An ascorbic acid sensor was fabricated via the drop-casting of dodecylbenzene sulphonic acid (DBSA)-doped polyaniline nanoparticles onto a screen-printed carbon-paste electrode. The modified electrode was characterised with respect to the numbers of drop cast layers, optimum potential and operating pH. The sensor was found to be optimal at neutral pH and at 0V vs. Ag/AgCl. Under these conditions, the sensor showed good selectivity and sensitivity in that it did not respond to a range of common interferents such as dopamine, acetaminophen, uric acid and citric acid, but was capable of the detection of ascorbic acid at a sensitivity of 0.76 microA mM(-1) or 10.75 microA mM(-1) cm(-2) across a range from 0.5 to 8mM (r2=0.996, n=6), and a limit of detection of 8.3 microM (S/N=3). The sensor was compared to a range of other conducting polymer-based ascorbate sensors and found to be comparable or superior in terms of analytical performance. PMID:18243871

  6. Study of radio-protective effects of ascorbic acid in rates

    International Nuclear Information System (INIS)

    The aim of this study was to evaluate the potential radio-protective effects of different ascorbic acid concentrations (vitamin C) in rats before whole body irradiation with total dose of 7 Gy (60Co source) using two different dose rates of 1 and 0.55 Gy.min-1 by increasing percent of surviving. In the first group (1 Gy/m); rats were administered four different concentrations of ascorbic acid (7.5, 12.5, 100, 200 mg/kg b wt ) in drinking water for 30 days before irradiation starting from the ablactation which considered as day 0. Whereas, in the second group (0.55 Gy/m); rats were administered six different concentrations of ascorbic acid (1, 5, 7.5, 12.5, 100, 200 mg/kg b wt) before irradiation with total dose 7 Gy (60Co source). The results have showed that the ascorbic acid enhance the 30-day survival of irradiated rats in 1 and 0.55 Gy/m groups, compared to the control group. The mean cumulated probability of survival of rats (1 Gy/m group) was 66%± 6 (Mean± S.E), 69%± 5, 52%± 9 and 51%± 9 in groups of rats which administered 7.5, 12.5, 100, 200 mg/kg, respectively, versus 41%± 9 in control group for 14 days. While, it was 90%± 2, 90%± 2, 88%± 2, 94%± 1, 84%± 3 and 78%± 3 in groups of rats which administered 1, 5, 7.5, 12.5, 100, 200 mg/kg respectively, versus 52%± 6 in control group for 30 days. Our data, also, indicated that all ascorbic acid concentrations in both groups had significant reduction in mortality and increasing percent of surviving compared to the control groups. We conclude that all ascorbic acid concentrations which used in both groups (1 and 0.55 Gy/m), had radioprotective effects in rats when administrated before irradiations, and this role was more effective against lower dose rate of radiation exposure. (author)

  7. Effects of ascorbic acid on cell mediated, humoral immune response and pathophysiology of

    Directory of Open Access Journals (Sweden)

    Suchint Simaraks

    2003-05-01

    Full Text Available The purpose of this study was to conduct an experiment related to the effects of chronic heat stress on total white blood cell changes, pathophysiology of leukocyte and effects of ascorbic acid on lymphocytes, lympholytic cells and humoral immunity of New-castle disease of broilers under chronic heat stress. Randomized complete block was the design. One hundred-forty-four chickens were maintained at 33+1 oC environmental temperature and on four levels of added ascorbic acid i.e. 0 (control group, 200, 400 and 800 mg/kg in dietsfor 21 days. On days 1, 3, 7, 14 and 21 of the experimental period, total white blood cells count, lympholytic cell and HI titer for Newcastle disease were determined. On day 21, histopathology of lung, liver, kidney, heart and bursa of fabricius of randomly selected broilers (n=36; 3 birds per experimental unit were studied. Total white blood cells (TWBC of the birds were significantly increased on day 3 (P<0.05 and were higheston days 7 and 14 then significantly decreased on days 21 (P<0.05. Monocytes were significantly increased on day 3 (P<0.05. Lymphocytes were significantly increased on day 7, and were highest on day 14 (P<0.05. On day 21, the value of lymphocyte was significantly lower than on days 7 and 14 (P<0.05, respectively. Lympholytic cells were significantly increased on day 3 and 7 (P<0.05, respectively, but on day 21, lympholyticcells were significantly decreased to lower value than on day 7 (P<0.05. Heterophils were significantly increased on day 3 and 7 and then decreased on day 14 (P<0.05. Tissue injury and hemorrhage in broilers under chronic heat stress caused leukocytosis, heterophilia, lympholysis and monocytosis. The size of lobules within the bursa of fabricius in broilers receiving ascorbic acid at 800 mg/kg in the diet were larger than inbirds that received added ascorbic acid at 400, 200 and 0 mg/kg in their diets, respectively. Lymphocytes and lympholytic cells were not significantly different among the ascorbic acid treatment groups. Besides, HI titers of Newcastle disease at 800 mg/kg in the diet were significantly higher than the others (P<0.05. Apparently, adding ascorbic acid at 800 mg/kg in the diet could improve humoral immunity in broilers under heat stress.

  8. Nonenzymatic amperometric sensor for ascorbic acid based on hollow gold/ruthenium nanoshells

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Ara; Kang, Minkyung; Cha, Areum; Jang, Hye Su [Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750 (Korea, Republic of); Shim, Jun Ho [Department of Chemistry, Daegu University, Gyeongsan 712-714 (Korea, Republic of); Lee, Nam-Suk [National Center for Nanomaterials Technology (NCNT), Pohang University of Science and Technology (POSTECH), Pohang 790-784 (Korea, Republic of); Kim, Myung Hwa [Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750 (Korea, Republic of); Lee, Youngmi, E-mail: youngmilee@ewha.ac.kr [Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750 (Korea, Republic of); Lee, Chongmok, E-mail: cmlee@ewha.ac.kr [Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750 (Korea, Republic of)

    2014-03-01

    Highlights: • We synthesized hollow gold/ruthenium (hAu–Ru) nanoshells for ascorbic acid sensing. • The hAu–Ru nanoshells showed sensitivity of 426 μA mM⁻¹ cm⁻² for ascorbic acid. • Good selectivity against glucose, uric acid, dopamine, 4-acetamidophenol, and NADH. • The linear dynamic range appeared from zero to 2.0 mM (R = 0.9995). • Response time (1.6 s) and low detection limit (2.2 μM) were obtained at pH 7.40. Abstract: We report a new nonenzymatic amperometric detection of ascorbic acid (AA) using a glassy carbon (GC) disk electrode modified with hollow gold/ruthenium (hAu–Ru) nanoshells, which exhibited decent sensing characteristics. The hAu–Ru nanoshells were prepared by the incorporation of Ru on hollow gold (hAu) nanoshells from Co nanoparticle templates, which enabled AA selectivity against glucose without aid of enzyme or membrane. The structure and electrocatalytic activities of the hAu–Ru catalysts were characterized by spectroscopic and electrochemical techniques. The hAu–Ru loaded on GC electrode (hAu–Ru/GC) showed sensitivity of 426 μA mM⁻¹ cm⁻² (normalized to the GC disk area) for the linear dynamic range of <5 μM to 2 mM AA at physiological pH. The response time and detection limit were 1.6 s and 2.2 μM, respectively. Furthermore, the hAu–Ru/GC electrode displayed remarkable selectivity for ascorbic acid over all potential biological interferents, including glucose, uric acid (UA), dopamine (DA), 4-acetamidophenol (AP), and nicotinamide adenine dinucleotide (NADH), which could be especially good for biological sensing.

  9. Nonenzymatic amperometric sensor for ascorbic acid based on hollow gold/ruthenium nanoshells

    International Nuclear Information System (INIS)

    Highlights: • We synthesized hollow gold/ruthenium (hAu–Ru) nanoshells for ascorbic acid sensing. • The hAu–Ru nanoshells showed sensitivity of 426 ?A mM?1 cm?2 for ascorbic acid. • Good selectivity against glucose, uric acid, dopamine, 4-acetamidophenol, and NADH. • The linear dynamic range appeared from zero to 2.0 mM (R = 0.9995). • Response time (1.6 s) and low detection limit (2.2 ?M) were obtained at pH 7.40. - Abstract: We report a new nonenzymatic amperometric detection of ascorbic acid (AA) using a glassy carbon (GC) disk electrode modified with hollow gold/ruthenium (hAu–Ru) nanoshells, which exhibited decent sensing characteristics. The hAu–Ru nanoshells were prepared by the incorporation of Ru on hollow gold (hAu) nanoshells from Co nanoparticle templates, which enabled AA selectivity against glucose without aid of enzyme or membrane. The structure and electrocatalytic activities of the hAu–Ru catalysts were characterized by spectroscopic and electrochemical techniques. The hAu–Ru loaded on GC electrode (hAu–Ru/GC) showed sensitivity of 426 ?A mM?1 cm?2 (normalized to the GC disk area) for the linear dynamic range of <5 ?M to 2 mM AA at physiological pH. The response time and detection limit were 1.6 s and 2.2 ?M, respectively. Furthermore, the hAu–Ru/GC electrode displayed remarkable selectivity for ascorbic acid over all potential biological interferents, including glucose, uric acid (UA), dopamine (DA), 4-acetamidophenol (AP), and nicotinamide adenine dinucleotide (NADH), which could be especially good for biological sensing

  10. Factors affecting plasma Contents of thiamine and Ascorbic acid in Camels (Camelus dromedarius)

    OpenAIRE

    H.E. Mohamed

    2006-01-01

    The study was designed to investigate the effect of age, breed, sex, and breeding season on thiamine and ascorbic acid status (AA) in camels (Camelus dromedarius). A total of 375 camels were sampled over a one-year field survey in Butana area, Central Sudan. No effect of sex on thiamine and ascorbic acid levels was observed. The breeding male and female camels showed higher status of plasma thiamine and lower ascorbic acid as compared to non-breeding camels. Thiamine plasma contents showed va...

  11. Uptake of ascorbic acid by freshly isolated cells and secretory granules from the intermediate lobe of ox hypophyses

    DEFF Research Database (Denmark)

    Zhou, A; Matsumoto, T; Farver, O; Thorn, N A

    1990-01-01

    Mechanically isolated cells from the intermediate lobe of ox hypophyses contained 40.6 +/- 3.7 nmol mg-1 protein (mean +/- SE, n = 5) of ascorbic acid. They accumulated radioactivity time dependently, on incubation with L-[14C]ascorbic acid in ionic medium dominated by NaCl. No definite saturation...... L-[14C]ascorbic acid were homogenized and placed on a Percoll gradient, the radioactivity was recovered in several subcellular fractions. Decrease of the Na+ concentration or presence of ouabain in the medium did not cause noticeable changes in uptake by non-purified cells, whereas uptake by...

  12. Uptake of ascorbic acid by freshly isolated cells and secretory granules from the intermediate lobe of ox hypophyses

    DEFF Research Database (Denmark)

    Zhou, A; Matsumoto, T; Farver, O; Thorn, N A

    1990-01-01

    Mechanically isolated cells from the intermediate lobe of ox hypophyses contained 40.6 +/- 3.7 nmol mg-1 protein (mean +/- SE, n = 5) of ascorbic acid. They accumulated radioactivity time dependently, on incubation with L-[14C]ascorbic acid in ionic medium dominated by NaCl. No definite saturation of uptake occurred when mechanically isolated cells were incubated with increasing ascorbic acid concentrations up to 0.6 mM. But if such cells were purified on a Percoll gradient, a clear saturation o...

  13. Effects of Ascorbic Acid on the Performance and Some Blood Parameters of Japanese Quails Reared Under Hot Climate Conditions

    OpenAIRE

    AVCI, Mehmet

    2005-01-01

    The effects of ascorbic acid on the performance and some blood parameters of Japanese quails reared under hot conditions were investigated. Three hundred Japanese quails, 7 days of age, were randomly divided into one control and two experimental groups, comprising five replicates of 20 birds each. Ascorbic acid (500 and 1000 mg/kg) was given to the experimental groups. The body weight gain increased significantly (P < 0.05) in the group given 500 mg/kg of ascorbic acid until the fourth wee...

  14. Determination of uric acid in the presence of ascorbic acid with hexacyanoferrate lanthanum film modified electrode

    International Nuclear Information System (INIS)

    A glassy carbon electrode modified with LaHCF was constructed and was characterized by cyclic voltammetry (CV) and electrochemical impedance spectrum (EIS). The resulting LaHCF modified glassy carbon electrode had a good catalytic character on uric acid (UA) and was used to detect uric acid and ascorbic acid (AA) simultaneously. This modified electrode exhibits potent and persistent electron-mediating behavior followed by well-separated oxidation peaks towards UA and AA with activation overpotential. For UA and AA in mixture, one can well separate from the other with a potential large enough to allow the determination of one in presence of the other. The DPV peak currents obtained increased linearly on the UA in the range of 2.0 x 10-7 to 1.0 x 10-4 mol/L with the detection limit (signal-to-noise ratio was 3) for UA 1.0 x 10-7 mol/L. The proposed method showed excellent selectivity and stability, and the determination of UA and AA simultaneously in urine was satisfactory

  15. Structure, spectra and antioxidant action of ascorbic acid studied by density functional theory, Raman spectroscopic and nuclear magnetic resonance techniques.

    Science.gov (United States)

    Singh, Gurpreet; Mohanty, B P; Saini, G S S

    2016-02-15

    Structure, vibrational and nuclear magnetic resonance spectra, and antioxidant action of ascorbic acid towards hydroxyl radicals have been studied computationally and in vitro by ultraviolet-visible, nuclear magnetic resonance and vibrational spectroscopic techniques. Time dependant density functional theory calculations have been employed to specify various electronic transitions in ultraviolet-visible spectra. Observed chemical shifts and vibrational bands in nuclear magnetic resonance and vibrational spectra, respectively have been assigned with the help of calculations. Changes in the structure of ascorbic acid in aqueous phase have been examined computationally and experimentally by recording Raman spectra in aqueous medium. Theoretical calculations of the interaction between ascorbic acid molecule and hydroxyl radical predicted the formation of dehydroascorbic acid as first product, which has been confirmed by comparing its simulated spectra with the corresponding spectra of ascorbic acid in presence of hydrogen peroxide. PMID:26580511

  16. Structure, spectra and antioxidant action of ascorbic acid studied by density functional theory, Raman spectroscopic and nuclear magnetic resonance techniques

    Science.gov (United States)

    Singh, Gurpreet; Mohanty, B. P.; Saini, G. S. S.

    2016-02-01

    Structure, vibrational and nuclear magnetic resonance spectra, and antioxidant action of ascorbic acid towards hydroxyl radicals have been studied computationally and in vitro by ultraviolet-visible, nuclear magnetic resonance and vibrational spectroscopic techniques. Time dependant density functional theory calculations have been employed to specify various electronic transitions in ultraviolet-visible spectra. Observed chemical shifts and vibrational bands in nuclear magnetic resonance and vibrational spectra, respectively have been assigned with the help of calculations. Changes in the structure of ascorbic acid in aqueous phase have been examined computationally and experimentally by recording Raman spectra in aqueous medium. Theoretical calculations of the interaction between ascorbic acid molecule and hydroxyl radical predicted the formation of dehydroascorbic acid as first product, which has been confirmed by comparing its simulated spectra with the corresponding spectra of ascorbic acid in presence of hydrogen peroxide.

  17. Mutagenicity of Acridine and Ascorbic Acid in Rhizobia of Legume Trees

    Directory of Open Access Journals (Sweden)

    M.A. Nassef

    2002-01-01

    Full Text Available The present study aimed to induce a great variation existing among Rhizobium spp. that nodulate Leucaena leucocephala and Sesbania sesban, through the treatment with acridine and ascorbic acid and selection of isolates for efficiency in the symbiotic association. Bacteria were isolated from nodules of both hosts growing in Egyptian soil, subcultured, and verified to be rhizobia. The isolates varied significantly in their resistance to antibiotics and NaCl, their growth on different carbohydrates, and their effect on the pH of culture media. Most isolates showed intermediate antibiotic resistance, the capacity to use numerous carbohydrates, and a neutral to acid pH response. The mean generation time of these isolates ranged from 4.813 to 6.437 and 4.600 to 6.523 for Sesbania sesban and Leucaena leucocephala, respectively. Both acridine orange and ascorbic acid had genotoxic hazards on all rhizobial strains examined here. They demonstrated a dose-response for decreasing cell survival at the levels that are not excessively toxic to bacteria. The standard assay with pre-incubation was quite toxic to the bacteria than plate incorporation test. Acridine orange and ascorbic acid shows an increase in number of auxotrophic mutants over the spontaneous value which is evidence for their mutagenicity caused by DNA damage. The biochemical mutants obtained in this study were identified using nine plates of minimal medium, each supplemented with different combinations of four growth factors. From the results reported here, it can be concluded that acridine mutagenesis is due to an enhancement of mismatch repair. In addition, ascorbic acid may be mutagenic and cytotoxic through the generation of hydrogen peroxide.

  18. Effect of combination treatment of gamma irradiation and ascorbic acid on physicochemical and microbial quality of minimally processed eggplant (Solanum melongena L.)

    Science.gov (United States)

    Hussain, Peerzada R.; Omeera, A.; Suradkar, Prashant P.; Dar, Mohd A.

    2014-10-01

    Gamma irradiation alone and in combination with ascorbic acid was tested for preventing the surface browning and maintaining the quality attributes of minimally processed eggplant. Eggplant samples after preparation were subjected to treatment of gamma irradiation in the dose range of 0.25-1.0 kGy and to combination treatments of ascorbic acid dip at a concentration of 2.0% w/v and gamma irradiation (dose range 0.5-2.0 kGy) followed by storage at 3±1 °C, RH 80%. Studies revealed inverse correlation (r=-0.93) between the polyphenol oxidase (PPO) activity, browning index and the treatments of ascorbic acid and gamma irradiation. Combinatory treatment of 2.0% w/v ascorbic acid and 1.0 kGy gamma irradiation proved to be significantly (p?0.05) effective in inhibiting the PPO activity, preventing the surface browning and maintaining the creamy white color and other quality attributes of minimally processed eggplant up to 6 days of refrigerated storage. Sensory evaluation revealed that control and 0.25 kGy irradiated samples were unacceptable only after 3 days of storage. Samples irradiated at 0.5 kGy and 0.75 kGy were unacceptable after 6 days of storage. Microbial analysis revealed that radiation processing of minimally processed eggplant at 1.0 kGy with and without ascorbic acid resulted in around 1 and 1.5 log reduction in yeast and mold count as well as bacterial count just after treatment and 6 days of storage therefore, enhances the microbial safety.

  19. The crystal structure and physicochemical properties of L-ascorbic acid 2-glucoside.

    Science.gov (United States)

    Mandai, T; Yoneyama, M; Sakai, S; Muto, N; Yamamoto, I

    1992-08-01

    The stable L-ascorbic acid glucoside produced by the action of the cyclomaltodextrin glucanotransferase (CGTase, EC 2.4.1.19) from Bacillus stearothermophilus was crystallized from an aqueous solution. Determination of the molecular structure by single crystal X-ray analysis showed the compound to be 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G). The crystals are orthorhombic, space group P2(1)2(1)2(1), with unit-cell dimensions a = 11.929 A, b = 24.351 A, and c = 4.864 A. The D-glucopyranose residue has the 4C1 conformation. These conclusions are in good agreement with those based on the 13C-NMR spectrum. The general physicochemical properties of crystalline AA-2G are reported. PMID:1423355

  20. Stability studies of ascorbic acid 2-glucoside in cosmetic lotion using surface response methodology.

    Science.gov (United States)

    Huang, Wen-Ying; Lee, Pei-Chi; Huang, Ling-Kuei; Lu, Li-Ping; Liao, Wayne C

    2013-03-15

    Ascorbic acid 2-glucoside (AA-2G) has been widely used in cream and lotion types of cosmetic products. Thus, the degradation of AA-2G caused by the temperature change and pH variation was very critical for determining the bio-functionality of cosmetics. Response surface methodology (RSM) was introduced to study the influence of temperature and pH on the stability of AA-2G. The optimal condition of retaining AA-2G with the highest stability was determined to be 55.3°C and pH 6.4. The antioxidative activities of AA-2G including DPPH and ABTS free radical scavenging activities, metal chelating activity, and reducing ability were also determined. AA-2G was a good ascorbic acid derivative which could be used in cosmetic products as an active ingredient. PMID:23416010

  1. Modulating effect of ascorbic Acid on transport-induced immunosuppression in goats.

    Science.gov (United States)

    Minka, Ndazo Salka; Ayo, Joseph Olusegun

    2011-01-01

    The effect of 12?h road transportation on some basic blood cells and the modulating role of ascorbic acid were investigated in 40 adult Red Sokoto goats during the hot dry season. The animals were divided into two groups, GI (experimental; n = 20) and GII (control; n = 20). Group 1 was administered with ascorbic acid (AA) per os at a dosage rate of 100?mg/kg body weight, while GII was given 10?mL of sterile water per goat. Forty minutes after the administration and loading, the goats were transported for 12?h. The result obtained in GII goats showed that loading, transportation, high ambient temperature (AT), and relative humidity (RH) encountered during transportation induced lymphopenia, neutrophilia, and eosinopenia, which can cause immunosuppression. In GI goats, the administration of AA prior to loading and transportation ameliorated the adverse effects of loading and transportation stress on neutrophil/lymphocyte ratio and eosinopenia of the goats. PMID:23738106

  2. Efficacy of Ascorbic Acid Reducing Waterborne Copper Toxicity in Butterfish (Poronotus triacanthus

    Directory of Open Access Journals (Sweden)

    Wannee Jiraungkoorskul

    2007-01-01

    Full Text Available This study was investigated the effects of copper (Cu and Ascorbic Acid (AA on butterfish (Poronotus triacanthus, using the micronucleus (MN and Nuclear Abnormality (NA tests for the period of 7, 14 and 21 days. NA shapes in erythrocytes were scored into blebbed nuclei (BL, lobed nuclei (LB, notched nuclei (NT and binuclei (BN. It was observed that, fish showed significant sensitivity to the different treatments. In general, the highest value of both MN and NA cells were significantly increased in the Cu treated group followed by the combination of Cu and AA treated group. These values revealed the highest number after 21 days treatment in all cases. The frequencies of each NA shape in erythrocytes of all treatments were observed in the following NT> LB> BN> BL. Present results demonstrated the efficacy of ascorbic acid in reducing genotoxicity in fish induced by waterborne copper.

  3. The oxidative degradation of barley ?-glucan in the presence of ascorbic acid or hydrogen peroxide.

    Science.gov (United States)

    Mäkelä, Noora; Sontag-Strohm, Tuula; Maina, Ndegwa Henry

    2015-06-01

    Cereal ?-glucans are polysaccharides with health benefits that have been linked to their ability to increase luminal viscosity. However, the functional properties of cereal ?-glucans may be diminished by the susceptibility of this polysaccharide to oxidative degradation. In this study, barley ?-glucan was oxidised with hydrogen peroxide or ascorbic acid and the oxidative degradation of ?-glucan was investigated using both asymmetrical flow field-flow fractionation (AsFlFFF) with aqueous solvent and high performance size exclusion chromatography (HPSEC) with LiBr in DMSO as the solvent. Oxidation was shown to cause degradation of ?-glucan, the reaction being faster when oxidised with hydrogen peroxide compared with ascorbic acid. Both HPSEC and AsFlFFF showed comparable results as long as aggregates (only observed in AsFlFFF) were not included in the integration. The compact aggregates observed in oxidised samples suggest oxidation driven interactions between ?-glucan molecules. PMID:25843872

  4. A Flexible Ascorbic Acid Fuel Cell with a Microchannel Fabricated using MEMS Techniques

    Science.gov (United States)

    Mogi, Hiroshi; Fukushi, Yudai; Koide, Syohei; Sano, Ryohei; Sasaki, Tsubasa; Nishioka, Yasushiro

    2013-12-01

    We fabricated a miniature ascorbic acid fuel cells equipped with a microchannel for the circulation of ascorbic acid (AA) solution using micro electronic mechanical system techniques. The fuel cell was fabricated on a flexible polyimide substrate, and its porous carbon-coated aluminium (Al) electrodes of 2.8 mm in width and 11 mm in length were formed using photolithography and screen-printing techniques. The porous carbon was deposited by screen-printing of carbon-black ink on the Al electrode surfaces in order to increase the effective electrode surface area and to absorb more enzymes on the cathode surface. The microchannel with a depth of 200 ?m was fabricated using a hot-embossing technique. A maximum power of 0.60 ?W at 0.58 V that corresponds to a power density of 1.83 ?W/cm2 was realized by introducing a 200 mM concentrated AA solution at room temperature.

  5. The effect of ascorbic acid on collagen of lungs and kidneys of irradiated rats

    International Nuclear Information System (INIS)

    The effect of ascorbic acid, on the radiation induced changes in collagen of lung and kidney tissues, was evaluated in rats after whole body fractionated gamma irradiation. Animals received a dose of 7.5 Gy given in 3 fractions of 2.5 Gy every 3 days. Collagen content determined by hydroxyproline assay was carried out 1,2,3, and 4 weeks after irradiation. Progressive increase in collagen content of lungs starting from 2 nd week up to 4 th week, and at 3 weeks for kidney, was observed. Data obtained showed that intraperitoneal administration of ascorbic acid 10 mg/100 grams body weight 10 minutes before irradiation to each fraction appears capable of reducing the radiation induced collagen in the lung but not in the kidney. 2 tabs

  6. A Flexible Ascorbic Acid Fuel Cell with a Microchannel Fabricated using MEMS Techniques

    International Nuclear Information System (INIS)

    We fabricated a miniature ascorbic acid fuel cells equipped with a microchannel for the circulation of ascorbic acid (AA) solution using micro electronic mechanical system techniques. The fuel cell was fabricated on a flexible polyimide substrate, and its porous carbon-coated aluminium (Al) electrodes of 2.8 mm in width and 11 mm in length were formed using photolithography and screen-printing techniques. The porous carbon was deposited by screen-printing of carbon-black ink on the Al electrode surfaces in order to increase the effective electrode surface area and to absorb more enzymes on the cathode surface. The microchannel with a depth of 200 ?m was fabricated using a hot-embossing technique. A maximum power of 0.60 ?W at 0.58 V that corresponds to a power density of 1.83 ?W/cm2 was realized by introducing a 200 mM concentrated AA solution at room temperature

  7. Solubilities of magnesium-L-ascorbate, calcium-L-ascorbate, magnesium-L-glutamate, magnesium-D-gluconate, calcium-D-gluconate, calcium-D-heptagluconate, L-aspartic acid, and 3-nitrobenzoic acid in water

    International Nuclear Information System (INIS)

    The solubility in water of magnesium-L-ascorbate, calcium-L-ascorbate, magnesium-L-glutamate, magnesium-D-gluconate, calcium-D-gluconate, calcium-D-heptagluconate, L-aspartic acid, and 3-nitrobenzoic acid was determined in the 278.15 K to 343.15 K temperature range. The solubility of these compounds served to permit the evaluation of the apparent molar enthalpies of solution

  8. Role of ascorbic acid supplement in reducing oxidative stress and hepatotoxicity in lead intoxication

    International Nuclear Information System (INIS)

    Objective: The present study was conducted to measure the oxidative stress and hepatotoxicity in lead intoxicated sprague dawley rats with and without supplementation of ascorbic acid. Study Design: Randomized Control Trial. Place of Study: Physiology Department, Army Medical College, Rawalpindi. (From Oct 2007 to Sep 2008) Material and Methods: One hundred and five male rats (age, 90-120 days; weight 200 - 250 gm) were divided into three groups each having 35 rats. Rats of group 1 and group 2 were given weekly injections of sodium acetate (10 mg /kg body weight) and lead acetate (10 mg /kg body weight) respectively, whereas rats of group 3 were administered lead acetate(10 mg /kg body weight) through weekly injections and ascorbic acid in drinking water (500 mg/l). After 6 weeks, 4 ml of blood was drawn from each rat by cardiac puncture. The blood was allowed to clot and serum was separated for estimation of serum malondialdehyde (MDA) levels on spectrophotometer; and serum alanine aminotransferase (ALT) levels and aspartate aminotransferase (AST) levels on Merck Micorlab 200. Results: Lead intoxication of rats revealed that serum MDA levels were raised to 7.8 +- 0.48 micro mol/l (control, 3.2 +-0.39 micro mol/l), ALT levels to 76.26 +- 5.88 IU/l (control, 44.1 +- 3.26) and AST levels to 258.06 +- 13.30 IU/l (control, 156.2 +- 4.97). Ascorbic acid supplementation significantly lowered serum MDA levels (3.8 +- 0.34 micro mol/l), ALT levels (52.26 +-4.57 IU/l) and AST levels (188.13 +- 12.91 IU/l). Conclusion: Ascorbic acid supplementation ameliorates lead intoxication probably by reducing the oxidative stress, thus preventing the development of hepatotoxicity, but this amelioration is not equal to the control. (author)

  9. Influence of refrigeration length and of sugar addition on ascorbic acid content in some natural juices

    OpenAIRE

    Marcel Avramiuc; Liviu Fartaies

    2009-01-01

    Following some studies concerning the main factors influencing the concentration of vitamins within food raw materials, especially ascorbic acid, this work tries to evidence the influence of the refrigeration temperature and of the sucrose addition on content of this vitamin in three types of natural juice. The biological material was represented by orange, strawberry and kivi natural juices, obtained from these fruits by means a crushing out process. For each type of juice there ...

  10. Elimination of ascorbic acid after high-dose infusion in prostate cancer patients

    DEFF Research Database (Denmark)

    Nielsen, Torben Kjær; Højgaard, Martin; Andersen, Jon Thor Trærup; Poulsen, Henrik Enghusen; Lykkesfeldt, Jens; Mikines, Kari Joensen

    2015-01-01

    Treatment with high-dose intravenous (IV) ascorbic acid (AA) is used in complementary and alternative medicine for various conditions including cancer. Cytotoxicity to cancer cell lines has been observed with millimolar concentrations of AA. Little is known about the pharmacokinetics of high dose IV AA. The purpose of the present study was to assess the basic kinetic variables in human beings over a relevant AA dosing interval for proper design of future clinical trials. Ten patients with metast...

  11. Effect of ascorbic acid on food preference and consumption in captive capybaras (Hydrochoerus hydrochaeris)

    Scientific Electronic Library Online (English)

    Martín Roberto, Alvarez; Fernando Osvaldo, Kravetz.

    2009-06-01

    Full Text Available O ácido ascórbico é um nutriente essencial para as capivaras (Hydrochoerus hydrochaeris). No presente trabalho foi avaliado o efeito do ácido ascórbico sobre o consume e as preferências alimentares a curto e longo prazo, assim como a influencia da escolha sobre a sintomatologia da carência de vitami [...] na C na dieta. Não foram observadas diferencias no consumo de alimento na ausência deste nutriente. Considerando as preferências a longo prazo (24h), os animais acostumados a consumir vitamina C continuavam consumindo preferencialmente o alimento suplementado. As preferências alimentares em capivaras não parecem depender da disponibilidade de ácido ascórbico; no entanto, quando acostumados à vitamina C, estes animais podem reconhecer e selecionar o ácido ascórbico na alimentação subseqüente. São discutidos os mecanismos que permitem as capivaras "avaliar" a qualidade nutricional do alimento, assim como o valor adaptativo destes comportamentos em populações silvestres. Abstract in english The aim of this work was to study the short and long term influences of ascorbic acid on Hydrochoerus hydrochaeris, if supplemented in their food. No differences regarding food intake were observed in the absence of vitamin C. On a daily basis, animals accustomed to food containing ascorbic acid pre [...] fered to continue eating the same food. Food preference in capybaras did not seem to depend on ascorbic acid availability; however, when accustomed to vitamin C, capybaras might recognize and select ascorbic acid in subsequent food. Mechanisms allowing capybaras to "evaluate" the nutritional quality of their food are discussed, as well as the adaptive value of this behavior in free ranging populations.

  12. Effect of Dietary Ascorbic Acid on Performance of Broiler Chickens Exposed to Different Lighting Regime

    OpenAIRE

    A.I. Okwori; P.C. Njoku; C.D. Tuleun

    2010-01-01

    A 2 x 2 factorial experiment was conducted to determine the performance of 400 Anak broiler chicks exposed to two lighting regimes viz. 12 h light:12 h darkness and 24 h light:0 h darkness and fed diets containing two levels of ascorbic acid (0 and 250 mg AA/kg of feed). Each treatment was replicated four times with 25 birds per replicate. Results showed that at the starter phase of growth, chicks on continuous lighting regime recorded significantly (p

  13. Spectroscopic investigation of the interaction between {beta}-cyclodextrin and ascorbic acid

    Energy Technology Data Exchange (ETDEWEB)

    Bratu, Ioan; Kacso, Irina [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania); Muresan-Pop, Marieta [Babes-Bolyai University, Faculty of Physics, 1 Mihail Kogalniceanu 400084 Cluj-Napoca (Romania); Farcas, Sorin I, E-mail: ioan.bratu@itim-cj.r

    2009-08-01

    Inclusion compound of vitamin C (ascorbic acid) with {beta}-cyclodextrin ({beta}-CD), prepared by different methods (kneading, co-precipitation and freeze-drying) has been caracterized by several spectroscopic techniques (FTIR, {sup 1}H NMR, UV-Vis), powder X-ray diffraction and DSC technique. Based on the chemical shifts observed in the {sup 1}H-NMR and on FTIR spectra the tentative conclusion is that vitamin C probably enters the cyclodextrin torus forming the inclusion complex.

  14. Comparative Study of Ascorbic Acid and Tocopherol Concentrations in Hydroponic- and Soil-Grown Lettuces

    OpenAIRE

    Drew N. Buchanan; Omaye, Stanley T.

    2013-01-01

    Hydroponically-grown produce may be a way of helping to feed the world a variety of fruits and vegetables, regardless of soil quality, space availability or climate. The objective of this study was to determine whether hydroponicallygrown lettuce contains as much ascorbic acid and tocopherol as soil-grown lettuce. We analyzed four varieties of lettuce, including: Waldmann’s Dark Green, Red Lollo Antago, Red Romaine Annapolis, and Butterleaf. The tocopherol content of hydroponically-grown Wald...

  15. Killing of Bacillus Spores by Aqueous Dissolved Oxygen, Ascorbic Acid, and Copper Ions

    OpenAIRE

    Cross, J. B.; Currier, R. P.; Torraco, D. J.; Vanderberg, L. A.; Wagner, G. L.; Gladen, P. D.

    2003-01-01

    An approach to decontamination of biological endospores is discussed. Specifically, the performance of an aqueous modified Fenton reagent is examined. A modified Fenton reagent formulation of cupric chloride, ascorbic acid, and sodium chloride is shown to be an effective sporicide under aerobic conditions. The traditional Fenton reaction involves the conversion of hydrogen peroxide to hydroxyl radical by aqueous ionic catalysts such as the transition metal ions. Our modified Fenton reaction i...

  16. Exogenous application of ascorbic acid stimulates growth and photosynthesis of wheat (Triticum aestivum L.) under drought

    OpenAIRE

    Samina Malik and Muhammad Ashraf

    2012-01-01

    Drought causes considerable reduction in plant growth. A hydroponic experiment was conducted to appraise the potential role of exogenously applied ascorbic acid in alleviating the effect of drought on wheat. Two contrasting wheat genotypes, a drought tolerant cultivar Chakwal-86 and a drought sensitive strain 6544-6 were used in the study. Drought was induced by dissolving 20% Polyethylene glycol (PEG8000) in the nutrient solution producing -0.6MPa osmotic stress. Drought caused a significant...

  17. Antioxidant capacity and contents of phenols, ascorbic acid, ?-carotene and lycopene in lettuce

    OpenAIRE

    Zdravkovi? Jasmina M.; A?amovi?-?okovi? Gordana S.; Mladenovi? Jelena D.; Pavlovi? Radoš M.; Zdravkovi? Milan S.

    2014-01-01

    The antioxidant activity of three lettuce varieties (Lactuca sativa L.) Emerald, Vera and Neva, cultivated in two kinds of protected spaces, a glasshouse and a plastic greenhouse, under controlled conditions, was determined. The content of antioxidant compounds: total phenols, flavonoids, L-ascorbic acid, ß-carotene and lycopene, were determined in ethanolic extracts of the lettuce with spectrophotometric methods. The largest content of total phenols (78.98...

  18. SIMULTANEOUS ELECTROCHEMICAL DETECTION OF DOPAMINE, ASCORBIC ACID AND URIC ACID USING COPPER-PHTHALOCYANINE FUNCTIONALIZED MWCNTS

    Scientific Electronic Library Online (English)

    MAMIE, SANCY; J, FRANCISCO SILVA; JORGE, PAVEZ; JOSÉ H, ZAGAL.

    2013-12-01

    Full Text Available Multiwalled carbon nanotububes functionalized with amino groups (MWCNT-NH2) and further modified with copper-phthalocyaninetetrasulphonate (4ß(SO3) CuPc) were used for preparing a hybrid electrode [MWCNT-NH2/4ß(SO3)CuPc/GC] using glassy carbon (GC) as a support. This hybrid electrode was tested for [...] the detection of dopamine (DA) in the presence of ascorbic acid (AA) and uric acid (UA) in a PBS buffer solution at pH 6.8. The presence of the macrocyclic increased the resolution of the oxidation signals of AA, DA and UA into three very well distinct oxidation peaks. This effect was enhanced when the complex is adsorbed on multiwalled carbon nanotubes. In addition, the hybrid films provide a simple method for selective detection of DA, AA and UA in biological samples. The calibration curves for DA were obtained over the range of 1x10-6-1x10-3M, obtaining a good selectivity and sensitivity.

  19. Changes in Ascorbic Acid Content, Antioxidant Capacity and Sensory Quality of Fresh-cut Mangosteens During Storage

    Directory of Open Access Journals (Sweden)

    Supranee MANURAKCHINAKORN

    2004-06-01

    Full Text Available Fresh-cut mangosteens, stored in modified atmosphere packaging (MAP; 5% O2 + 9% CO2, in vacuum packaging (VAC and in air (AIR were examined for ascorbic acid content, antioxidant capacity and sensory quality during 14 days of storage at 4oC. After 4 days-storage, fresh-cut fruits with MAP resulted in better retention of ascorbic acid and antioxidant capacity than those stored in AIR throughout the storage. Furthermore, there were no significant differences in ascorbic acid contents between fruits stored in MAP and VAC, as well as antioxidant capacities, during the remaining period of storage. Fresh-cut fruits with MAP treatment obtained the highest sensory scores, compared with other treatments, throughout the entire period of storage. Fresh-cut mangosteens stored in MAP resulted in the best overall retention of ascorbic acid, antioxidant capacity and sensory quality.

  20. IMPACT OF EXTRACELLULAR CALCIUM ALONG WITH ASCORBIC ACID ON CELLULAR REACTIVATION AND INSULIN SECRETION IN DIABETIC MIN6 CELLS

    Directory of Open Access Journals (Sweden)

    Priyanka Sharma

    2011-01-01

    Full Text Available Diabetes is not a single disease but characterized by a group of syndromes. Oxidative stress and defects in insulin secretory pathway are the major problems associated with type 2 diabetes. Extracellular Ca2+ influx is the major trigger which stimulates insulin secretion in pancreatic β cells. In this study we combined the most common antioxidant ascorbic acid with extracellular calcium to observe their cooperative effect on diabetic MIN6 cells. Our results demonstrated firstly the major role of ascorbic acid individually as well as with calcium in cell viability as compared to individual calcium supplementation. Secondly, the combined concentration of ascorbic acid and calcium leads to maximum increase in insulin level in dose dependent manner upto 5mM ascorbic acid and decrease beyond this concentration.

  1. Evaluation of non-thermal effects of electricity on ascorbic acid and carotenoid degradation in acerola pulp during ohmic heating.

    Science.gov (United States)

    Jaeschke, Débora Pez; Marczak, Ligia Damasceno Ferreira; Mercali, Giovana Domeneghini

    2016-05-15

    The effect of electric field on ascorbic acid and carotenoid degradation in acerola pulp during ohmic heating was evaluated. Ascorbic acid kinetic degradation was evaluated at 80, 85, 90 and 95°C during 60min of thermal treatment by ohmic and conventional heating. Carotenoid degradation was evaluated at 90 and 95°C after 50min of treatment. The different temperatures evaluated showed the same effect on degradation rates. To investigate the influence of oxygen concentration on the degradation process, ohmic heating was also carried out under rich and poor oxygen modified atmospheres at 90°C. Ascorbic acid and carotenoid degradation was higher under a rich oxygen atmosphere, indicating that oxygen is the limiting reagent of the degradation reaction. Ascorbic acid and carotenoid degradation was similar for both heating technologies, demonstrating that the presence of the oscillating electric field did not influence the mechanisms and rates of reactions associated with the degradation process. PMID:26775953

  2. Radioprotection potential of the ascorbic acid on the carrageenan used as food additive

    International Nuclear Information System (INIS)

    Carrageenans are a group of natural carbohydrates that are present in the structure of certain varieties of red algae (Rhodophyceae). They are used in emulsions, for syneresis control and to grow up, to promote adhesiveness and dispersion. In the industry of foods they can be used for instance, as thickness and gelling agents, alone or together with other additives. The processing of foods by radiation is increasing considerably, because the efficiency of the process in the industrial decontamination of products. The objective of this work was to study the action of the ascorbic acid as potential radioprotector of the carrageenan against 60 Co gamma radiation effects, using the viscosity as parameter. Samples of commercial carrageenan dissolved at 1,0% were irradiated in the presence or not of ascorbic acid, with doses of 0.0 kGy; 1.0 kGy; 2.5 kGy; 5.0 kGy and 10.0 kGy. After the irradiation the relationships viscosity/dose were established for the temperature of 60 deg C. For the dose of 10.0 kGy a better protecting effect of the ascorbic acid on the carrageenan was seen. The implications of the use of this antioxidant is discussed as a form of minimizing the effect of the radiation in irradiated foods. (author)

  3. Preparation of (99m)Tc labeled vitamin C (ascorbic acid) and biodistribution in rats.

    Science.gov (United States)

    Yigit, Ugur Sezai; Lambrecht, Fatma Yurt; Unak, Perihan; Biber, Fazilet Zümrüt; Medine, Emin Ilker; Cetinkaya, Berkan

    2006-01-01

    The aim of this study was to label ascorbic acid with (99m)Tc and to investigate its radiopharmaceutical potential in rats. Ascorbic acid was labeled with (99m)Tc using the stannous chloride method. The radiochemical purity of [(99m)Tc]ascorbic acid ((99m)Tc-AA) was determined by RTLC, paper electrophoresis, and RHPLC methods. The labeling yield was found to be 93+/-5.0%. The maximum labeling yield of (99m)Tc-AA was determined at pH 5 and 25 degrees C. The biodistribution studies related to (99m)Tc-AA were done in male albino Wistar rats. (99m)Tc-AA, which has a specific activity of 13.02 GBq/mmol, was administered into the tail vein of the rats. The rats were sacrificed at 15, 30, 60, and 120 min after the injection by heart puncture under ether anaesthesia. The organs were weighed after removal. Their activities were counted using a Cd(Te) detector equipped with a RAD 501 count system. The %ID/g (% of injected dose per gram of tissue weight) in each organ and in blood was calculated. Maximum uptake of (99m)Tc-AA was observed in prostate and kidneys at the 60th min. (99m)Tc-AA may be a promising radiopharmaceutical for the imaging of prostate and kidneys. PMID:16394539

  4. Characterization of L-ascorbic acid single crystals grown from solution with different solvents

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, K.; Vanitha Devi, K. [Crystal Growth Laboratory, Department of Physics, School of Physical Sciences, Bharathiar University, Coimbatore-641 046, Tamil Nadu (India)

    2010-09-15

    Single crystals of L-ascorbic acid, popularly known as vitamin-C, were grown from solutions with different solvents and solvent combinations by low temperature solution growth methods. The suitability of different solvents and solvent combinations such as acetone, ethanol, methanol, isopropyl alcohol, water, water + acetone (1:1), water + ethanol (3:1), water + isopropyl alcohol (3:1) and isopropyl alcohol + methanol (1:1) for crystal growth of L-ascorbic acid was found out by assessing the solubility and crystallization behaviours. Solubility of L-ascorbic acid in selected solvents and solvent combinations in a range of temperatures was determined by gravimetric method. Solution prepared with water, water + acetone (1:1), water + ethanol (3:1) and water + isopropyl alcohol (3:1) were yielded crystals with tabular, columnar and prismatic habits and their morphologies were evaluated by goniometry. Grown single crystals were characterized with various instrumental techniques such as powder X-ray diffraction, Fourier infrared spectroscopy, optical transmittance study, differential scanning calorimetry and second harmonic generation studies. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. IMPROVEMENT OF SALT TOLERANCE IN DURUM WHEAT BY ASCORBIC ACID APPLICATION

    Directory of Open Access Journals (Sweden)

    Fercha Azzedine

    2011-03-01

    Full Text Available The main objective of this study is to examine whether exogenously applied Ascorbic acid (AsA may enhance the salt tolerance in durum wheat (Triticum durum Desf. var. Waha. Two weeks old seedling, grown in plastic pots of 1kg, were subjected to salt stress by adding 25ml of NaCl (150mm, and treated or not with the addition of ascorbic acid (0.7 mM. Two weeks after salt stress, plants were harvested and the various measures were recorded.The effects of salt stress, in the presence and absence of vitamin C, on the leaf growth, leaf area (LA and some physiological and biochemical changes were investigated. It was established that the application of vitamin C mitigate to variable extent the adverse effect of salt stress on plant growth, may be due, in part, to increased leaf area, improved chlorophyll and carotenoid contents, enhanced proline accumulation and decreased H2O2 content.In conclusion, we can say that treatment with ascorbic acid improve salt tolerance in durum wheat through the enhancement of multiple processes.

  6. Influence of refrigeration length and of sugar addition on ascorbic acid content in some natural juices

    Directory of Open Access Journals (Sweden)

    Liviu Fartaies

    2009-06-01

    Full Text Available Following some studies concerning the main factors influencing the concentration of vitamins within food raw materials, especially ascorbic acid, this work tries to evidence the influence of the refrigeration temperature and of the sucrose addition on content of this vitamin in three types of natural juice. The biological material was represented by orange, strawberry and kivi natural juices, obtained from these fruits by means a crushing out process. For each type of juice there were made up samples without addition and samples with 5% and 10% sucrose addition. The ascorbic acid determination was carried out from fresh juice as well as from juice kept in refrigerator, at certain time intervals (24, 48, 96 ?i 168 hours. The storage of these juices under refrigeration conditions has determined percentage reductions of vit. C content of these ones. Thus, after 168 hours of storage, in the three types of analysed juices the highest loss of vitamin have been registrated in samples without sucrose addition, and the least ones in samples with 10% addition. The comparison of vitamin C values in the three analysed juices, subjected 168 hours to refrigeration process, has evidenced that the highest loss of ascorbic acid have been in orange juice, and the least one in kiwi juice. Keywords: vitamin C, sucrose, orange, strawberry, kiwi

  7. Radiation protective effects of cysteamine and glutathione on four nucleobases and ascorbic acid in aqueous solution

    International Nuclear Information System (INIS)

    This paper shows the radiation protective effects of cysteamine and glutathione (reduced form) on the ?-systems of four nucleobases in aqueous solution. Thymine, cytosine, adenine, and guanine solutions containing cysteamine (or glutathione) in various concentrations were irradiated with gamma-rays from a 0.22 PBq Co-60 source. The residual concentration of each nucleobase after irradiation was measured by spectrophotometry and liquid chromatography. The ?-systems of cytosine and adenine were protected and repaired by adding about a 3-6 fold excess of cysteamine in relative to the cytosine and the adenine concentration. Each amino group, cytosine and adenine, plays an important role for the protection of their own ?-system from the radiation damage. The ?-system of thymine was protected from the radiation damage, but was not repaired by cysteamine. The protective effects of cysteamine on guanine were saturated with increasing the cysteamine concentration. Ascorbic acid solutions containing cysteamine were irradiated also. The radiation protective effect of cysteamine on ascorbic acid was small. A first approximation analysis was made on the radiation protective effects. The autooxidation of ascorbic acid in aqueous solution containing several kinds of antioxidants was measured and analyzed. (author)

  8. Genotoxicity and oxidative stress of microwave radiation role of ascorbic acid

    International Nuclear Information System (INIS)

    Radiofrequency fields and especially microwaves are very important part of electromagnetic spectrum that can produce generations of reactive oxygen species, and thus can affect DNA and cause chromosomal aberrations. So this effect can be diminished by the supplement of an antioxidant such as ascorbic acid. In this study, the proposed protective role of ascorbic acid was tested against the EMF induced chromosomal aberrations and lipid peroxidation. The present study proved that EMF had a clastogenic effect on the bone marrow cells of mice, either with the exposure to EMF; 950 MHz or frequency EMF; 2450 MHz. This effect was evidenced by structural and numerical chromosomal aberrations. The study also proved that EMF had an effect on oxidative stress, evidenced by increase in the level of lipid peroxide, in a dose dependent manner. So, the mechanism of EMF induced chromosomal aberrations can be explained by this oxidative stress induced by EMF exposure. The present study showed that ascorbic acid had a protective effect against both EMF induced chromosomal aberrations and oxidative stress, when it is applied concomitantly with EMF exposure either at frequency of 950 MHz or 2450 MHz. this is evident by decreases in the level of lipid peroxide and decrease in chromosomal aberrations

  9. Effect of ascorbic acid and particle size on iron absorption from ferric pyrophosphate in adult women.

    Science.gov (United States)

    Fidler, Meredith C; Davidsson, Lena; Zeder, Christophe; Walczyk, Thomas; Marti, Irene; Hurrell, Richard F

    2004-07-01

    The effects of added ascorbic acid and particle size on iron absorption from ferric pyrophosphate were evaluated in adult women (9-10 women/study) based on erythrocyte incorporation of iron stable isotopes (57Fe or 58Fe) 14 days after administration. Three separate studies were made with test meals of iron-fortified infant cereal (5 mg iron/meal) and the results are presented as geometric means and relative bioavailability values (RBV, FeSO4 = 100%). The results of study 1 showed that iron absorption was significantly lower from ferric pyrophosphate (mean particle size 8.5 microm) than from FeSO4 in meals without ascorbic acid (0.9 vs. 2.6%, p ferric pyrophosphate slightly less (2.6-fold) than from FeSO4 (3.7-fold) (p ferric pyrophosphate with an average particle size of 6.7 microm and 12.5 pm was not significantly different at 52 and 42% (p > 0.05), respectively. In conclusion, the addition of ascorbic acid increased fractional iron absorption from ferric pyrophosphate significantly, but to a lesser extent than from FeSO4. Decreasing the mean particle size to 6.7 microm did not significantly increase iron absorption from ferric pyrophosphate. PMID:15580812

  10. Status of lipid peroxidation, glutathione, ascorbic acid, vitamin E and antioxidant enzymes in patients with osteoarthritis

    Directory of Open Access Journals (Sweden)

    Surapaneni Krishna

    2007-01-01

    Full Text Available Background : The exact pro-oxidant and antioxidant status in osteoarthritis patients is still not clear. To add a new insight to the question, changes in the erythrocyte lipid peroxidation products (MDA, levels of glutathione (GSH, ascorbic acid and plasma vitamin E (nonenzymatic antioxidant parameters; and activities of antioxidant enzymes superoxide dismutase (SOD, glutathione peroxidase (GPX, catalase in erythrocytes and plasma glutathione - S - transferase (GST were measured in patients with osteoarthritis. Aim: This work was undertaken to assess oxidative stress and antioxidant status in patients with osteoarthritis. Settings and design: The study was conducted in 20 patients and compared to controls. Levels of erythrocyte MDA, GSH, ascorbic acid, plasma vitamin E; and activities of antioxidant enzymes were measured in patients with osteoarthritis. materials and Methods: Erythrocyte GSH was measured by the method of Beutler et al. Ascorbic acid levels were measured by the method of Tietz. Plasma vitamin E levels were measured by the method of Baker et al. MDA was determined as the measure of thio barbituric acid reactive substances (TBARS. SOD activity in the hemolysate was measured by the method of Misra and Fridovich. Activity of catalase was measured by the method of Beers and Sizer. GPX activity was measured as described by Paglia and Valentine in erythrocytes, and Plasma GST activity was measured as described by Warholm et al. These parameters were measured in 20 patients and compared to controls. Statistical analysis: Statistical analysis between group 1 (controls and group 2 (patients was performed by the student′s t - test using the stat -view package. Results: It was observed that there was a significant increase in erythrocyte MDA levels; SOD, GPX and plasma GST activities; and a significant decrease in erythrocyte GSH, ascorbic acid, plasma vitamin E levels and catalase activity in patients with osteoarthritis when compared to controls. Conclusions: The results of our study suggest higher oxygen-free radical production, evidenced by increased MDA and decreased GSH, ascorbic acid, vitamin E and catalase activity, support to the oxidative stress in osteoarthritis. The increased activities of antioxidant enzymes may be a compensatory regulation in response to increased oxidative stress.

  11. INFLUENCE OF ASCORBIC ACID ON SCLEROTIA PRODUCTION OF DESCENDANCE OF SOME CLAVICEPS PURPUREA HYBRID AND NON-HYBRID PARENTAL STRAINS

    OpenAIRE

    Maria+Magdalena Zamfirache; Zenovia Olteanu; Stefania Surdu; Elena Truta

    2006-01-01

    This paper includes the experimental results regarding the effects of ascorbic acid, present in culture media, on the phenotypisation of “sclerotia/ha production” character. The behaviour of descendance of some monoparental and hybrid strains of Claviceps purpurea is analysed; the obtained data evidenced variations of strain bioproductivity, under the influence of ascorbic acid, variations which can be correlated with strain origin, alkaloid type etc.

  12. INFLUENCE OF ASCORBIC ACID ON SCLEROTIA PRODUCTION OF DESCENDANCE OF SOME CLAVICEPS PURPUREA HYBRID AND NON-HYBRID PARENTAL STRAINS

    Directory of Open Access Journals (Sweden)

    Maria+Magdalena Zamfirache

    2006-08-01

    Full Text Available This paper includes the experimental results regarding the effects of ascorbic acid, present in culture media, on the phenotypisation of “sclerotia/ha production” character. The behaviour of descendance of some monoparental and hybrid strains of Claviceps purpurea is analysed; the obtained data evidenced variations of strain bioproductivity, under the influence of ascorbic acid, variations which can be correlated with strain origin, alkaloid type etc.

  13. Inhibition of cell proliferation and migration by oxidative stress from ascorbate-driven juglone redox cycling in human bladder-derived T24 cells

    International Nuclear Information System (INIS)

    Highlights: ► The cytotoxicity of juglone is markedly increased by ascorbate. ► T24 cell death by oxidative stress is necrosis-like. ► Redox cycling by juglone/ascorbate inhibits cell proliferation. ► Cellular migration is impaired by juglone/ascorbate. -- Abstract: The effects of juglone on T24 cells were assessed in the presence and absence of ascorbate. The EC50 value for juglone at 24 h decreased from 28.5 μM to 6.3 μM in the presence of ascorbate. In juglone-treated cells, ascorbate increased ROS formation (4-fold) and depleted GSH (65%). N-acetylcysteine or catalase restricted the juglone/ascorbate-mediated effects, highlighting the role of oxidative stress in juglone cytotoxicity. Juglone alone or associated with ascorbate did not cause caspase-3 activation or PARP cleavage, suggesting necrosis-like cell death. DNA damage and the mild ER stress caused by juglone were both enhanced by ascorbate. In cells treated with juglone (1–5 μM), a concentration-dependent decrease in cell proliferation was observed. Ascorbate did not impair cell proliferation but its association with juglone led to a clonogenic death state. The motility of ascorbate-treated cells was not affected. Juglone slightly restricted motility, but cells lost their ability to migrate most noticeably when treated with juglone plus ascorbate. We postulate that juglone kills cells by a necrosis-like mechanism inhibiting cell proliferation and the motility of T24 cells. These effects are enhanced in the presence of ascorbate.

  14. Inhibition of cell proliferation and migration by oxidative stress from ascorbate-driven juglone redox cycling in human bladder-derived T24 cells

    Energy Technology Data Exchange (ETDEWEB)

    Kviecinski, M.R., E-mail: mrkviecinski@hotmail.com [Laboratorio de Bioquimica Experimental, Departamento de Bioquimica, Universidade Federal de Santa Catarina, Florianopolis (Brazil); Pedrosa, R.C., E-mail: rozangelapedrosa@gmail.com [Laboratorio de Bioquimica Experimental, Departamento de Bioquimica, Universidade Federal de Santa Catarina, Florianopolis (Brazil); Felipe, K.B., E-mail: kakabettega@yahoo.com.br [Laboratorio de Bioquimica Experimental, Departamento de Bioquimica, Universidade Federal de Santa Catarina, Florianopolis (Brazil); Farias, M.S., E-mail: mirellesfarias@hotmail.com [Laboratorio de Bioquimica Experimental, Departamento de Bioquimica, Universidade Federal de Santa Catarina, Florianopolis (Brazil); Glorieux, C., E-mail: christophe.glorieux@uclouvain.be [Toxicology and Cancer Biology Research Group, Louvain Drug Research Institute, Universite Catholique de Louvain, 73 Avenue E. Mounier, GTOX 7309, 1200 Brussels (Belgium); Valenzuela, M., E-mail: mavalenzuela@med.uchile.cl [Toxicology and Cancer Biology Research Group, Louvain Drug Research Institute, Universite Catholique de Louvain, 73 Avenue E. Mounier, GTOX 7309, 1200 Brussels (Belgium); Sid, B., E-mail: brice.sid@uclouvain.be [Toxicology and Cancer Biology Research Group, Louvain Drug Research Institute, Universite Catholique de Louvain, 73 Avenue E. Mounier, GTOX 7309, 1200 Brussels (Belgium); and others

    2012-05-04

    Highlights: Black-Right-Pointing-Pointer The cytotoxicity of juglone is markedly increased by ascorbate. Black-Right-Pointing-Pointer T24 cell death by oxidative stress is necrosis-like. Black-Right-Pointing-Pointer Redox cycling by juglone/ascorbate inhibits cell proliferation. Black-Right-Pointing-Pointer Cellular migration is impaired by juglone/ascorbate. -- Abstract: The effects of juglone on T24 cells were assessed in the presence and absence of ascorbate. The EC{sub 50} value for juglone at 24 h decreased from 28.5 {mu}M to 6.3 {mu}M in the presence of ascorbate. In juglone-treated cells, ascorbate increased ROS formation (4-fold) and depleted GSH (65%). N-acetylcysteine or catalase restricted the juglone/ascorbate-mediated effects, highlighting the role of oxidative stress in juglone cytotoxicity. Juglone alone or associated with ascorbate did not cause caspase-3 activation or PARP cleavage, suggesting necrosis-like cell death. DNA damage and the mild ER stress caused by juglone were both enhanced by ascorbate. In cells treated with juglone (1-5 {mu}M), a concentration-dependent decrease in cell proliferation was observed. Ascorbate did not impair cell proliferation but its association with juglone led to a clonogenic death state. The motility of ascorbate-treated cells was not affected. Juglone slightly restricted motility, but cells lost their ability to migrate most noticeably when treated with juglone plus ascorbate. We postulate that juglone kills cells by a necrosis-like mechanism inhibiting cell proliferation and the motility of T24 cells. These effects are enhanced in the presence of ascorbate.

  15. Effects of ascorbic acid and oxalic acid on uptake and translocation of zinc in maize (Zea Mays L.) using 65Zn radiotracer

    International Nuclear Information System (INIS)

    This study was done to evaluate the effect of oxalic and ascorbic acids on 65Zn uptake and translocation in Maize plants through solution culture experiment so that the desired acid remains available in the roots zone

  16. Influence of antioxidant (L- ascorbic acid on tolbutamide induced hypoglycaemia/antihyperglycaemia in normal and diabetic rats

    Directory of Open Access Journals (Sweden)

    Vardhan Vishnu A

    2005-03-01

    Full Text Available Abstract Background Diabetes mellitus is a chronic metabolic disorder characterized by hyperglycaemia. Increased oxidative stress and decreased antioxidant levels are the leading cause of diabetes and diabetic complications. So it is felt that supplementation of antioxidants may be useful in controlling the glucose levels and to postpone the occurrence of diabetic complications. The objective of our study is to find the influence of antioxidant supplementation (L-ascorbic acid on tolbutamide activity in normal and diabetic rats. Methods L- ascorbic acid/tolbutamide/L-ascorbic acid + tolbutamide were administered orally to 3 different groups of albino rats of either sex in normal and diabetic condition. Blood samples were collected from retro-orbital puncture at different time intervals and were analyzed for blood glucose by GOD-POD method. Diabetes was induced by alloxan 100 mg/kg body weight administered by I.P route. Results L-ascorbic acid/ tolbutamide produced hypoglycaemic activity in a dose dependant manner in normal and diabetic condition. In the presence of L-ascorbic acid, tolbuatmide produced early onset of action and maintained for longer period compared to tolbutamide matching control. Conclusion Supplementation of antioxidants like L-ascorbic acid was found to improve tolbutamide response in normal and diabetic rats.

  17. Effect of combination treatment of gamma irradiation and ascorbic acid on physicochemical and microbial quality of minimally processed eggplant (Solanum melongena L.)

    International Nuclear Information System (INIS)

    Gamma irradiation alone and in combination with ascorbic acid was tested for preventing the surface browning and maintaining the quality attributes of minimally processed eggplant. Eggplant samples after preparation were subjected to treatment of gamma irradiation in the dose range of 0.25–1.0 kGy and to combination treatments of ascorbic acid dip at a concentration of 2.0% w/v and gamma irradiation (dose range 0.5–2.0 kGy) followed by storage at 3±1 °C, RH 80%. Studies revealed inverse correlation (r=?0.93) between the polyphenol oxidase (PPO) activity, browning index and the treatments of ascorbic acid and gamma irradiation. Combinatory treatment of 2.0% w/v ascorbic acid and 1.0 kGy gamma irradiation proved to be significantly (p?0.05) effective in inhibiting the PPO activity, preventing the surface browning and maintaining the creamy white color and other quality attributes of minimally processed eggplant up to 6 days of refrigerated storage. Sensory evaluation revealed that control and 0.25 kGy irradiated samples were unacceptable only after 3 days of storage. Samples irradiated at 0.5 kGy and 0.75 kGy were unacceptable after 6 days of storage. Microbial analysis revealed that radiation processing of minimally processed eggplant at 1.0 kGy with and without ascorbic acid resulted in around 1 and 1.5 log reduction in yeast and mold count as well as bacterial count just after treatment and 6 days of storage therefore, enhances the microbial safety. - Highlights: • 2.0% ascorbic acid and 1.0 kGy inhibited PPO activity in minimally processed eggplant. • Above treatment maintained creamy white color and storage quality up to 6 days at 3±1 °C. • The treatment gave 1.5 log reductions in microbial counts, thus enhancing microbial safety. • The treatment can provide convenience to consumer and will reduce spoilage during storage

  18. Kinetics and Mechanism of Oxidation of L-Ascorbic Acid by Pt(IV)(aq) in Aqueous Hydrochloric Acid Medium

    OpenAIRE

    Sadhana Senapati; Das, S. P.; Patnaik, A. K.

    2012-01-01

    Reduction of [PtCl6]2? by L-ascorbic acid (H2ASc) in 0.1?M aqueous acid medium has been investigated spectrophotometrically under pseudo-first order condition at [PtCl6]2? = 0.005–0.007?mol?dm?3, 0.05 ? [H2ASc]/mol?dm?3 ? 0.3, 298?K ? T ? 308?K, [H+] = 0.14?mol?dm?3, I=0.5?mol?dm?3. The redox reaction follows the rate law: d[Pt(IV)]/dt = k[H2ASc][Pt(IV)], where k is the second-order rate constant and [H2ASc] is the total concentration of ascorbic acid. Electron transfer from [H2ASc] to Pt(IV)...

  19. Effect of Salicylic Acid and Ascorbic Acid on Germination Indexes and Enzyme Activity of Sorghum Seeds under Drought Stress

    Directory of Open Access Journals (Sweden)

    Tabatabaei S. A.

    2013-11-01

    Full Text Available Seed priming methods have been used to increase germination characteristics under stress conditions. The effects of drought stress (0, -4, -8, -12 and -16 bar and salicylic acid 25 ppm at 15 °C for 15 h and ascorbic acid 25 ppm at 15 °C for 15 h on germination percentage, germination index, means time to germination, normal seedling percentage and enzyme activity were assessed in the laboratory for sorghum seeds (Sorghum bicolor L.. Results showed that the highest germination percentage (83.33%, normal seedling percentage (69.67%, germination index (25.29 and the minimum means time to germination (2.87 were attained from priming with salicylic acid in control conditions. Therefore, seed priming significantly (p? 0.01 increased germination characteristics as compared to the unprimed under drought stress. Also, priming increased catalase and ascorbate peroxidase as compared to the unprimed seeds.

  20. Effect of L (+) ascorbic acid and monosodium glutamate concentration on the morphology of calcium carbonate

    Science.gov (United States)

    Saraya, Mohamed El-shahte Ismaiel

    2015-11-01

    In this study, monosodium glutamate and ascorbic acid were used as crystal and growth modifiers to control the crystallization of CaCO3. Calcium carbonate prepared by reacting a mixed solution of Na2CO3 with CaCl2 at ambient temperature, (25 °C), constant Ca++CO3-- molar ratio and pH with stirring. The polymorph and morphology of the crystals were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The results indicate that rhombohedral calcite was only formed in water without organic additives, and both calcite and spherical vaterite with various morphologies were produced in the presence of monosodium glutamate. The content of vaterite increased as the monosodium glutamate increased. In addition, spherical vaterite was obtained in the presence of different concentrations of ascorbic acid. The spherical vaterite posses an aggregate shape composed of nano-particles, ranging from 30 to 50 nm as demonstrated by the SEM and TEM analyses. Therefore, the ascorbic stabilizes vaterite and result in nano-particles compared to monosodium glutamate.

  1. A novel nanocomposites sensor for epinephrine detection in the presence of uric acids and ascorbic acids

    Energy Technology Data Exchange (ETDEWEB)

    Lu Xiaoquan, E-mail: luxq@nwnu.edu.cn [Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, LanZhou, 730070 (China); Li Yaya; Du Jie; Zhou Xibin; Xue Zhonghua; Liu Xiuhui; Wang Zhihua [Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, LanZhou, 730070 (China)

    2011-08-30

    Highlights: {center_dot} A novel PPy/AuNPs/SWCNTs nanomaterials biosensor was prepared to the selective determination of EP. {center_dot} The methods we employed to prepare PPy/AuNPs/SWCNTs nanomaterials are extremely simple. {center_dot} The PPy/AuNPs/SWCNTs nanocomposites biosensor we got from the results of experiments can totally eliminate the interference from AA and distinguish EP from UA. - Abstract: A novel nanocomposites film of conducting polymers including single-walled carbon nanotubes (SWCNTs), polypyrrole (PPy) and gold nanoparticles (AuNPs) modified electrode has been applied in voltammetric sensors to detect epinephrine (EP) sensitively when ascorbic acids (AA) and uric acids (UA) exist. The nanocomposites film of conducting polymers which show an excellent electrocatalystic activity for the oxidation of EP and UA was characterized by scanning electron microscopy (SEM) and electrochemical methods. The catalytic peak currents obtained from differential pulse voltammetry (DPV) increased linearly with increasing EP concentrations in the range of 4.0 x 10{sup -9}-1.0 x 10{sup -7} M with a detection limit of 2.0 x 10{sup -9} M (S/N = 3), respectively. The results showed that the nanocomposites of conducting polymers can selectively determine EP in the coexistence of a large amount of UA and AA. In addition, the sensor exhibited excellent sensitivity, selectivity and stability. The PPy/AuNPs/SWCNTs nanocomposites film can also be satisfactorily used for detecting EP in epinephrine hydrochloride injection when contain AA and UA, which also shows good recovery for determination of EP in some biological fluids.

  2. Simultaneous determination of ascorbic acid, dopamine and uric acid based on tryptophan functionalized graphene

    Energy Technology Data Exchange (ETDEWEB)

    Lian, Qianwen; He, Zhifang; He, Qian; Luo, Ai; Yan, Kaiwang; Zhang, Dongxia [Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Geography and Environment Science, Northwest Normal University, Lanzhou, 730070 (China); Lu, Xiaoquan, E-mail: Luxq@nwnu.edu.cn [Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, 730070 (China); Zhou, Xibin, E-mail: zhouxb@nwnu.edu.cn [Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Geography and Environment Science, Northwest Normal University, Lanzhou, 730070 (China)

    2014-05-01

    Highlights: • Trp-GR was synthesized by utilizing a facile ultrasonic method. • The material as prepared had well dispersivity in water and better conductivity than pure GR. • Trp-GR/GCE showed excellent potential for the determination of AA, DA and UA. • The proposed method was applied for the analysis of AA, DA and UA in real samples. - Abstract: A new type of tryptophan-functionalized graphene nanocomposite (Trp-GR) was synthesized by utilizing a facile ultrasonic method via ?–? conjugate action between graphene (GR) and tryptophan (Trp) molecule. The material as prepared had well dispersivity in water and better conductivity than pure GR. The surface morphology of Trp-GR was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The electrochemical behaviors of ascorbic acid (AA), dopamine (DA), and uric acid (UA) were investigated by cyclic voltammetry (CV) on the surface of Trp-GR. The separation of the oxidation peak potentials for AA–DA, DA–UA and UA–AA was about 182 mV, 125 mV and 307 mV, which allowed simultaneously determining AA, DA, and UA. Differential pulse voltammetery (DPV) was used for the determination of AA, DA, and UA in their mixture. Under optimum conditions, the linear response ranges for the determination of AA, DA, and UA were 0.2–12.9 mM, 0.5–110 ?M, and 10–1000 ?M, with the detection limits (S/N = 3) of 10.09 ?M, 0.29 ?M and 1.24 ?M, respectively. Furthermore, the modified electrode was investigated for real sample analysis.

  3. Absorption of folic acid and ascorbic acid from nutrient comparable beverages.

    Science.gov (United States)

    Carter, Brett; Monsivais, Pablo; Drewnowski, Adam

    2010-01-01

    One hundred percent fruit juices can help consumers increase the nutrient content of the diet since these beverages can be naturally rich in micronutrients. Micronutrient-fortified low-calorie beverages are an important alternative to those wishing to minimize their calorie intakes. However, little is known about the bioavailability of nutrients from fortified beverages relative to 100% fruit juices. The present study examined the bioavailability of ascorbic acid (AA) and folic acid (FA) in 100% orange juice (OJ) and a low-calorie beverage fortified with these nutrients. In a within-subjects, cross-over design, 12 adult men consumed a 591 mL serving of OJ, a low-calorie beverage fortified with AA and FA, and 1% low fat milk. Participants were aged 20 to 35 y, with body mass indexes between 20 and 30 kg/m(2). Blood plasma concentrations of AA and serum concentrations of FA were assayed by serial blood draws, made at 30 min intervals for 4.5 h. Blood plasma concentration of AA was significantly greater after ingestion of the fortified beverage compared to after OJ ingestion. However, the bioavailability of AA did not significantly differ from that of OJ. Analyses of FA indicated no significant difference between fortified beverage and OJ. Consumption of both vitamin containing beverages led to higher concentrations of AA and FA than the milk control. This study showed that similar levels of AA and FA bioavailability can be attained through ingestion of 100% OJ and a fortified beverage. PMID:21535602

  4. Simultaneous determination of ascorbic acid, dopamine and uric acid based on tryptophan functionalized graphene

    International Nuclear Information System (INIS)

    Highlights: • Trp-GR was synthesized by utilizing a facile ultrasonic method. • The material as prepared had well dispersivity in water and better conductivity than pure GR. • Trp-GR/GCE showed excellent potential for the determination of AA, DA and UA. • The proposed method was applied for the analysis of AA, DA and UA in real samples. - Abstract: A new type of tryptophan-functionalized graphene nanocomposite (Trp-GR) was synthesized by utilizing a facile ultrasonic method via ?–? conjugate action between graphene (GR) and tryptophan (Trp) molecule. The material as prepared had well dispersivity in water and better conductivity than pure GR. The surface morphology of Trp-GR was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The electrochemical behaviors of ascorbic acid (AA), dopamine (DA), and uric acid (UA) were investigated by cyclic voltammetry (CV) on the surface of Trp-GR. The separation of the oxidation peak potentials for AA–DA, DA–UA and UA–AA was about 182 mV, 125 mV and 307 mV, which allowed simultaneously determining AA, DA, and UA. Differential pulse voltammetery (DPV) was used for the determination of AA, DA, and UA in their mixture. Under optimum conditions, the linear response ranges for the determination of AA, DA, and UA were 0.2–12.9 mM, 0.5–110 ?M, and 10–1000 ?M, with the detection limits (S/N = 3) of 10.09 ?M, 0.29 ?M and 1.24 ?M, respectively. Furthermore, the modified electrode was investigated for real sample analysis

  5. A novel nanocomposites sensor for epinephrine detection in the presence of uric acids and ascorbic acids

    International Nuclear Information System (INIS)

    Highlights: · A novel PPy/AuNPs/SWCNTs nanomaterials biosensor was prepared to the selective determination of EP. · The methods we employed to prepare PPy/AuNPs/SWCNTs nanomaterials are extremely simple. · The PPy/AuNPs/SWCNTs nanocomposites biosensor we got from the results of experiments can totally eliminate the interference from AA and distinguish EP from UA. - Abstract: A novel nanocomposites film of conducting polymers including single-walled carbon nanotubes (SWCNTs), polypyrrole (PPy) and gold nanoparticles (AuNPs) modified electrode has been applied in voltammetric sensors to detect epinephrine (EP) sensitively when ascorbic acids (AA) and uric acids (UA) exist. The nanocomposites film of conducting polymers which show an excellent electrocatalystic activity for the oxidation of EP and UA was characterized by scanning electron microscopy (SEM) and electrochemical methods. The catalytic peak currents obtained from differential pulse voltammetry (DPV) increased linearly with increasing EP concentrations in the range of 4.0 x 10-9-1.0 x 10-7 M with a detection limit of 2.0 x 10-9 M (S/N = 3), respectively. The results showed that the nanocomposites of conducting polymers can selectively determine EP in the coexistence of a large amount of UA and AA. In addition, the sensor exhibited excellent sensitivity, selectivity and stability. The PPy/AuNPs/SWCNTs nanocomposites film can also be satisfactorily used for detecting EP in epinephrine hydrochloride injection when contain AA and UA, which also shows good recovery for determination of EP in some biological fluids.

  6. Industrialized cashew juices: variation of ascorbic acid and other physicochemical parameters Sucos de caju industrializados: variação no teor de ácido ascórbico e em outros parâmetros físico-químicos

    OpenAIRE

    Christiane de Queiroz Pereira; Flávia Conde Lavinas; Maria Lúcia Mendes Lopes; Vera Lúcia Valente-Mesquita

    2008-01-01

    Commercial cashew apple juice is widely accepted in the Brazilian market. Cashew apple has high content of ascorbic acid, an important nutrient to human beings. Ascorbic acid content in food can be affected by processing and storage conditions. Commercial cashew apple juice samples, ready-to-drink and concentrated, were analyzed. The ascorbic acid content, total titratable acidity, total soluble solids, and pH of the juices were determined during storage at 4 °C after the containers were open...

  7. Improvement of development of equine preantral follicles after 6 days of in vitro culture with ascorbic acid supplementation.

    Science.gov (United States)

    Gomes, R G; Lisboa, L A; Silva, C B; Max, M C; Marino, P C; Oliveira, R L; González, S M; Barreiros, T R R; Marinho, L S R; Seneda, M M

    2015-09-15

    The aim of this study was to evaluate the effects of different concentrations of ascorbic acid (25, 50, and 100 ?g/mL) in supplemented minimum essential medium (MEM+) on the development of equine preantral follicles that were cultured in vitro for 2 or 6 days. The contralateral ovaries (n = 5) from five mares in seasonal anestrus were collected from a local abattoir. Nine ovarian tissue fragments of approximately 5 × 5 × 1 mm were obtained from each animal. One fragment was immediately fixed and subjected to histologic analysis (control group; Day 0), and the other eight were placed in PBS supplemented with penicillin (200 IU/mL) and streptomycin (200 mg/mL) at 4 °C for 1 hour (during transport to the laboratory). The fragments were cultured in situ for 2 days (D2) or 6 days (D6) in MEM+ or MEM+ plus ascorbic acid at three different concentrations, establishing the following nine groups: control; MEM+ (D2); MEM+ (D6); MEM+ 25 ?g/mL of ascorbic acid (D2); MEM+ 25 ?g/mL of ascorbic acid (D6); MEM+ 50 ?g/mL of ascorbic acid (D2); MEM+ 50 ?g/mL of ascorbic acid (D6); MEM+ 100 ?g/mL of ascorbic acid (D2); and MEM+ 100 ?g/mL of ascorbic acid (D6). The preantral follicles were classified according to their stage (primordial, primary, secondary, or antral) and their morphology (normal or abnormal). Slides (n = 951) including 4450 histologic sections were evaluated. Follicles were observed in only 4.85% (216 of 4450) of the histologic sections. Of the 407 follicles evaluated, 120 were in the primordial stage and 287 were in different developmental stages; additionally, 43.5% were morphologically normal. After 6 days of culture, the groups cultured with 50 and 100 ?g/mL of ascorbic acid differed in terms of follicular development compared with the other groups. On the basis of occurrence of follicular development and the presence of viable follicles, it can be concluded that a positive effect of culture for 6 days in MEM+ supplemented with 50 and 100 ?g/mL of ascorbic acid was observed on equine ovarian fragments. PMID:26074067

  8. Design, synthesis and biological evaluation of novel l-ascorbic acid-conjugated pentacyclic triterpene derivatives as potential influenza virus entry inhibitors.

    Science.gov (United States)

    Wang, Han; Xu, Renyang; Shi, Yongying; Si, Longlong; Jiao, Pingxuan; Fan, Zibo; Han, Xu; Wu, Xingyu; Zhou, Xiaoshu; Yu, Fei; Zhang, Yongmin; Zhang, Liangren; Zhang, Lihe; Zhou, Demin; Xiao, Sulong

    2016-03-01

    Since the influenza viruses can rapidly evolve, it is urgently required to develop novel anti-influenza agents possessing a novel mechanism of action. In our previous study, two pentacyclic triterpene derivatives (Q8 and Y3) have been found to have anti-influenza virus entry activities. Keeping the potential synergy of biological activity of pentacyclic triterpenes and l-ascorbic acid in mind, we synthesized a series of novel l-ascorbic acid-conjugated pentacyclic triterpene derivatives (18-26, 29-31, 35-40 and 42-43). Moreover, we evaluated these novel compounds for their anti-influenza activities against A/WSN/33 virus in MDCK cells. Among all evaluated compounds, the 2,3-O,O-dibenzyl-6-deoxy-l-ascorbic acid-betulinic acid conjugate (30) showed the most significant anti-influenza activity with an EC50 of 8.7 ?M, and no cytotoxic effects on MDCK cells were observed. Time-of-addition assay indicated that compound 30 acted at an early stage of the influenza life cycle. Further analyses revealed that influenza virus-induced hemagglutination of chicken red blood cells was inhibited by treatment of compound 30, and the interaction between the influenza hemagglutinin (HA) and compound 30 was determined by surface plasmon resonance (SPR) with a dissociation constant of KD = 3.76 ?M. Finally, silico docking studies indicated that compound 30 and its derivative 31 were able to occupy the binding pocket of HA for sialic acid receptor. Collectively, these results suggested that l-ascorbic acid-conjugated pentacyclic triterpenes were promising anti-influenza entry inhibitors, and HA protein associated with viral entry was a promising drug target. PMID:26866456

  9. Exposure to ?-Tocopherol, Lutein or Ascorbic Acid improve Cumulus Expansion, Viability and Maturation of Swine Oocytes

    Directory of Open Access Journals (Sweden)

    Ileana Miclea

    2010-05-01

    Full Text Available Protection of the fatty acid and lipid components of oocytes that render them susceptible to free radical or other oxidative injury may prevent the damage currently associated with culture. The goal of this study was to establish the influence of several ?-tocopherol, lutein and ascorbic acid concentrations on swine oocyte maturation, viability and the function of cumulus cells in order to improve culture media. Pig oocytes were cultured for 45 hours at 37°C in 5% CO2 atmosphere; in M199 containing several ?-tocopherol (5, 10, 20, 40, 80 ?M, lutein (2.5, 4, 5, 8, 10 ?M or ascorbic acid (50, 150, 250, 500, 750 ?M concentrations and cumulus expansion was assessed. Afterwards oocytes were coloured using FDA, PI and Hoechst 33258. The differences between treatments were analyzed by the analysis of variance and interpreted using the Newman-Keuls method. When cultured in ?-tocopherol supplemented medium the number of expanded COCs to be scored as 3 was significantly greater (p<0.05 for the 5 and 40 ?M concentrations. The addition of 8 ?M lutein to the maturation medium lead to a significant (p<0.05 increase in the number of COCs that were scored at 4. For both ?-tocopherol and lutein additions the numbers of oocytes stained by FDA, as well as those stained by Hoechst were greater than the control without being statistically significant. When cultured in 150 and 500 ?M ascorbic acid the percentages of COCs scored at 4 were significantly lower (p<0.05 than the control. Also, significantly (p<0.05 fewer oocytes were stained with FDA when matured in 500 ?M. Differences between the control and the several concentrations were significant (p<0.05 for 150 and 750 ?M and distinctly significant (p<0.01 for 250 ?M.

  10. Sol-gel process for preparation of YBa2Cu4O8 from acidic acetates/ammonia/ascorbic acid systems

    International Nuclear Information System (INIS)

    YBa2Cu4Ox sols were prepared by addition of ammonia to acidic acetate solutions of Y3+, Ba2+, and Cu2+. Ascorbic acid was added to part of the sol. The resultant sols were gelled to a shard or a coating by evaporation at 60 C. Addition of ethanol to the sols facilitated formation of gel coatings, fabricated by a dipping technique, on Ag or glass or substrates. At 100 C, gels formed in the presence of ascorbic acid were perfectly amorphous, in contrast to crystalline acetate gels. The quality of coatings prepared from ascorbate gels was superior to that of acetate gel coatings

  11. l-dehydroascorbic acid can substitute l-ascorbic acid as dietary vitamin C source in guinea pigs

    OpenAIRE

    Henriette Frikke-Schmidt; Pernille Tveden-Nyborg; Jens Lykkesfeldt

    2015-01-01

    Vitamin C deficiency globally affects several hundred million people and has been associated with increased morbidity and mortality in numerous studies. In this study, bioavailability of the oxidized form of vitamin C (l-dehydroascorbic acid or DHA)—commonly found in vitamin C containing food products prone to oxidation—was studied. Our aim was to compare tissue accumulation of vitamin C in guinea pigs receiving different oral doses of either ascorbate or DHA. In all tissues tested (plasma, l...

  12. Evaluation of gamma irradiation effects on carotenoids, ascorbic acid and sugar contents of buriti fruit (Mauritia flexuosa L.)

    International Nuclear Information System (INIS)

    Buriti (Mauritia flexuosa L.), a typical fruit from the Northeast and Center-West Amazon of Brazil, is used in many regional dishes. It is considered an excellent source of carotenoids that are A vitamin precursors, showing a majority of beta-carotene. It also presents ascorbic acid and sugar contents. Many studies have indicated that the lack of A vitamin is the main cause of night blindness and xerophthalmia. Also, ascorbic acid deficiency may cause scorbutic disease. The use of food irradiation is growing and represents an economic benefit to agriculture through the reduction of post-harvesting losses while maintaining food nutritional quality. In this study, buriti in natura was treated with gamma irradiation with doses of 0.5 kGy and 1.0 kGy. The objective was to evaluate the irradiation effects on total carotenoids, ascorbic acid and sugars concentrations of buriti. The fruit was evaluated through the total carotenoids analysis, by spectrophotometry, and the carotenoids (alpha and beta-carotene and lutein), ascorbic acid and sugars were determined by high performance liquid chromatography (HPLC). The results showed that buriti is an excellent source of total carotenoids (44600 ?g/100 g). The irradiation of buriti with the dose of 0.5 kGy did not significantly change carotenoids and sugars contents. However, there was a reduction of ascorbic acid concentration with an increase of the dose, which may have been caused by irradiation or by intrinsic and extrinsic factors that alter ascorbic acid stability in food, converting ascorbic to dehydroascorbic acid, while keeping the C vitamin active form. (author)

  13. Effect of temperature variations during cooking and storage on ascorbic acid contents of vegetables: a comparative study

    International Nuclear Information System (INIS)

    Summary: Vegetables are generally boiled for cooking or stored in refrigerators. This results in loss of their nutritional values. Ascorbic acid is one of the important nutrients for human health. In this study, Ascorbic acid (vitamin-C) content of various vegetables of Pakistan was determined, and effect of boiling and freezing were compared with natural Ascorbic acid contents by HPLC. The maximum concentration of Ascorbic acid was found in green chilli: i.e. 105 mg /100 g in fresh state; while in boiled and frozen state its concentration is comparatively less: i.e. 85 and 92 mg/100 g respectively. The other vegetables like: cabbage, to mato, turnip, potato, spinach, onion, garlic, green pea, green beans and cauliflower contained greater amount of Ascorbic acid in their fresh state i.e. 30, 20, 25.3, 20, 30, 24.3, 31, 28.5, 30, 42 mg/100 g as compared to frozen (23.4, 13, 23.6, 15, 23.4, 14.1,25, 26.5, 27.0, and 39 mg/100g respectively) and boiled state (11.6, 9.3, 22.5, 10.0, 20.3, 13.1, 23, 25.2 and 35 mg /100g respectively). The minimum amount of Ascorbic acid was found in boiled state of carrot and lettuce: i.e. 4.0 mg/100 g. These results showed that freezing or boiling of vegetables causes significant lo ss of available Ascorbic acid contents, especially boiling. (author)

  14. Ascorbic Acid Biosynthesis and Brackish Water Acclimation in the Euryhaline Freshwater White-Rimmed Stingray, Himantura signifer.

    Science.gov (United States)

    Wong, Samuel Z H; Ching, Biyun; Chng, You R; Wong, Wai P; Chew, Shit F; Ip, Yuen K

    2013-01-01

    L-gulono-?-lactone oxidase (Gulo) catalyzes the last step of ascorbic acid biosynthesis, which occurs in the kidney of elasmobranchs. This study aimed to clone and sequence gulonolactone oxidase (gulo) from the kidney of the euryhaline freshwater stingray, Himantura signifer, and to determine the effects of acclimation from freshwater to brackish water (salinity 20) on its renal gulo mRNA expression and Gulo activity. We also examined the effects of brackish water acclimation on concentrations of ascorbate, dehydroascorbate and ascorbate + dehydroascorbate in the kidney, brain and gill. The complete cDNA coding sequence of gulo from the kidney of H. signifer contained 1323 bp coding for 440 amino acids. The expression of gulo was kidney-specific, and renal gulo expression decreased significantly by 67% and 50% in fish acclimated to brackish water for 1 day and 6 days, respectively. There was also a significant decrease in renal Gulo activity after 6 days of acclimation to brackish water. Hence, brackish water acclimation led to a decrease in the ascorbic acid synthetic capacity in the kidney of H. signifer. However, there were significant increases in concentrations of ascorbate and ascorbate + dehydroascorbate in the gills (after 1 or 6 days), and a significant increase in the concentration of ascorbate and a significant decrease in the concentration of dehydroascorbate in the brain (after 1 day) of fish acclimated to brackish water. Taken together, our results indicate that H. signifer might experience greater salinity-induced oxidative stress in freshwater than in brackish water, possibly related to its short history of freshwater invasion. These results also suggest for the first time a possible relationship between the successful invasion of the freshwater environment by some euryhaline marine elasmobranchs and the ability of these elasmobranchs to increase the capacity of ascorbic acid synthesis in response to hyposalinity stress. PMID:23825042

  15. INFLUENCE OF ASCORBIC ACID ON EGG QUALITY INFLUÊNCIA DO ÁCIDO ASCÓRBICO NA QUALIDADE DO OVO

    Directory of Open Access Journals (Sweden)

    Pedro Alves de SOUZA

    2001-12-01

    Full Text Available The egg quality may be influenced by some nutrients added to laying hens diets and among these nutrients, the ascorbic acid is included. According to some researches, this acid, besides of improving the quality, it can increase the egg production and weight. In addition, it reduces the quantity of cracked eggs and food intake. In order to contribute with more information, this experiment was developed. Concentrations of 100; 150 and 200mg/kg of ascorbic acid were added to rations of laying hens during 60 days, with the objective of determining the influence of ascorbic acid on the quality of eggs kept under room temperature conditions (26.7 ± 2.2°C and 60 ± 5% moisture for a period of 28 days. A total of 1440 eggs were used, being 720 of white shell and 720 of brown shell. Egg quality was determined by Haugh unit and yolk index, every 7 days. The obtained results allowed to conclude that ascorbic acid, independent on the level of supplementation, was not enough to decrease.A qualidade dos ovos pode ser influenciada por alguns nutrientes adicionados à dieta das aves e entre esses nutrientes se inclui o ácido ascórbico, que segundo alguns pesquisadores, além de melhorar a qualidade, pode aumentar a produção e o peso dos ovos e diminuir a quantidade de ovos trincados e o consumo de ração. Com a finalidade de tentar contribuir com mais algumas informações, desenvolveu esse experimento com o objetivo de avaliar a influência do ácido ascórbico sobre a qualidade de ovos brancos e marrons mantidos sob condições de ambiente (26,7 ± 2,2°C e 60 ± 5%UR, por um período de 28 dias. Foram utilizados 1440 ovos, sendo 720 de casca branca e 720 de casca marrom. Foram adicionadas à ração de aves, durante 60 dias, concentrações de 100, 150 e 200mg/kg de ácido ascórbico. A qualidade dos ovos foi determinada de 7 em 7 dias, avaliando-se a unidade Haugh e o índice gema. Os dados obtidos permitiram concluir que a suplementação com o ácido ascórbico não foi suficiente para diminuir a perda de qualidade dos ovos. Independentemente dos níveis de vitaminas utilizados, os ovos marrons mostraram-se qualitativamente superiores aos brancos.

  16. The Effect of Ascorbic Acid Treatment on Viability and Vigor Maize (Zea mays L. Seedling under Drought Stress

    Directory of Open Access Journals (Sweden)

    HAMIDAH HAMAMA

    2010-09-01

    Full Text Available This study was conducted in the laboratory and the field to examine the effects of ascorbic acid treatment on germination and seedling growth under drought stress. The laboratory works consisted of two experiments and were designed to determine the critical osmotic potential of maize and to determine the optimum ascorbic acid concentration. The field study was designed to examine the effects of soaking seed in ascorbic acid on seedling growth under drought stress. Drought condition was simulated by PEG-6000 and regulation of water treatment. During the first experiment, interactions of both osmotic potential and varieties were significant at all variables. Germination percentage and speed of germination were significantly decreased by increasing of osmotic potential. The second experiment showed that interactions of both factors were significant at all variables except vigor index, the length of shoot, primary, and seminal root. The results showed that the ascorbic acid treatment improved the germination percentage, the speed of germination and the vigor index compared with the control, besides the increase in length of shoot, primary and seminal root and number of seminal root. However, the best result was showed by 55 mM ascobic acid. The result of field experiment showed that interactions were not always significant and 55 mM ascorbic acid treatment increased the seedling height, the number of leaves and leaf area but it had no effect on the water deficit and the root length.

  17. Low Dose Gamma Irradiation Does Not Affect the Quality or Total Ascorbic Acid Concentration of “Sweetheart” Passionfruit (Passiflora edulis

    Directory of Open Access Journals (Sweden)

    John B. Golding

    2015-08-01

    Full Text Available Passionfruit (Passiflora edulis, Sims, cultivar “Sweetheart” were subject to gamma irradiation at levels suitable for phytosanitary purposes (0, 150, 400 and 1000 Gy then stored at 8 °C and assessed for fruit quality and total ascorbic acid concentration after one and fourteen days. Irradiation at any dose (?1000 Gy did not affect passionfruit quality (overall fruit quality, colour, firmness, fruit shrivel, stem condition, weight loss, total soluble solids level (TSS, titratable acidity (TA level, TSS/TA ratio, juice pH and rot development, nor the total ascorbic acid concentration. The length of time in storage affected some fruit quality parameters and total ascorbic acid concentration, with longer storage periods resulting in lower quality fruit and lower total ascorbic acid concentration, irrespective of irradiation. There was no interaction between irradiation treatment and storage time, indicating that irradiation did not influence the effect of storage on passionfruit quality. The results showed that the application of 150, 400 and 1000 Gy gamma irradiation to “Sweetheart” purple passionfruit did not produce any deleterious effects on fruit quality or total ascorbic acid concentration during cold storage, thus supporting the use of low dose irradiation as a phytosanitary treatment against quarantine pests in purple passionfruit.

  18. DNA damage and inhibition of akt pathway in mcf-7 cells and ehrlich tumor in mice treated with 1,4-naphthoquinones in combination with ascorbate.

    Science.gov (United States)

    Ourique, Fabiana; Kviecinski, Maicon R; Felipe, Karina B; Correia, João Francisco Gomes; Farias, Mirelle S; Castro, Luiza S E P W; Grinevicius, Valdelúcia M A S; Valderrama, Jaime; Rios, David; Benites, Julio; Calderon, Pedro Buc; Pedrosa, Rozangela Curi

    2015-01-01

    The aim of this study was to enhance the understanding of the antitumor mechanism of 1,4-naphthoquinones and ascorbate. Juglone, phenylaminonaphthoquinone-7, and 9 (Q7/Q9) were evaluated for effects on CT-DNA and DNA of cancer cells. Evaluations in MCF-7 cells are DNA damage, ROS levels, viability, and proliferation. Proteins from MCF-7 lysates were immunoblotted for verifying PARP integrity, ?H2AX, and pAkt. Antitumor activity was measured in Ehrlich ascites carcinoma-bearing mice. The same markers of molecular toxicity were assessed in vivo. The naphthoquinones intercalate into CT-DNA and caused oxidative cleavage, which is increased in the presence of ascorbate. Treatments caused DNA damage and reduced viability and proliferation of MCF-7 cells. Effects were potentiated by ascorbate. No PARP cleavage was observed. Naphthoquinones, combined with ascorbate, caused phosphorylation of H2AX and inhibited pAkt. ROS were enhanced in MCF-7 cells, particularly by the juglone and Q7 plus ascorbate. Ehrlich carcinoma was inhibited by juglone, Q7, or Q9, but the potentiating effect of ascorbate was reproduced in vivo only in the cases of juglone and Q7, which caused up to 60% inhibition of tumor and the largest extension of survival. Juglone and Q7 plus ascorbate caused enhanced ROS and DNA damage and inhibited pAkt also in Ehrlich carcinoma cells. PMID:25793019

  19. Stimulation of hepatocyte growth factor production by ascorbic acid and its stable 2-glucoside.

    Science.gov (United States)

    Wu, Y L; Gohda, E; Iwao, M; Matsunaga, T; Nagao, T; Takebe, T; Yamamoto, I

    1998-10-01

    Hepatocyte growth factor (HGF), a cytokine which is generally produced by mesenchymal cells, has mitogenic, motogenic and morphogenic activities in epithelial cells and it also has tumor-suppressing activities. Induction of HGF production may be involved in organ regeneration, wound healing and embryogenesis. We examined the effects of ascorbic acid (AsA), which stimulates the proliferation of fibroblasts, and its stable derivative, 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G), on HGF production by human skin fibroblasts. Basal HGF secretion was significantly stimulated by more than 0.1 mM AsA or AA-2G. Both vitamins synergistically enhanced HGF secretion stimulated by growth factors such as epidermal growth factor (EGF), platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF), cholera toxin and other inducers. Induction by EGF or bFGF was most markedly potentiated by the vitamins. HGF production by the KG-1 human leukemia cell line was also augmented by AsA or AA-2G. Another stable AsA derivative, ascorbic acid 2-phosphate (AA-2P) effectively promoted basal and EGF-induced HGF secretion by the fibroblasts, but ascorbic acid 2-sulfate (AA-2S) was much less effective. Intracellular AsA levels increased after the addition of AA-2G and AA-2P as well as AsA, but not after AA-2S. The effect of AA-2G was completely abrogated by the simultaneous addition of castanospermine, an alpha-glucosidase inhibitor, suggesting that the active form of AA-2G is AsA. Constitutive and EGF-induced HGF gene expression was also up-regulated after adding AsA or AA-2G to the cells. These results indicated that AsA acts alone or in synergy with several inducers to stimulate the production and gene expression of HGF in human skin fibroblasts and that the stable AsA derivative AA-2G is as effective as AsA in promoting HGF production. PMID:10984304

  20. Effects of lighting schedule and ascorbic acid on performance and tibiotarsus bone characteristics in broilers

    OpenAIRE

    YILDIZ, Hüseyin; Petek, Metin; Sönmez, Gürsel; ARICAN, ?lker; YILMAZ, Bestami

    2009-01-01

    This study was conducted to determine the effects of 2 lighting programs (continuous: 24 h light:0 h dark; intermittent: 12 h daylight followed by 3 cycles of 1 h light, and then 3 h dark during the night) and 3 ascorbic acid supplementations (0, 200, and 400 mg/L added to water) on broiler performance, bone characteristics, and the incidence of tibial dyschondroplasia. One-day-old male commercial (Ross PM3) broiler chicks (600) were divided into 6 treatment groups (2 × 3) with random replica...

  1. Influence of heating conditions and ascorbic acid concentration over furan formation in starchy model systems

    DEFF Research Database (Denmark)

    Mariotti, Salomé; Granby, Kit

    Furan, a potential carcinogen, can be formed in foods processed at high temperatures such as coffee, baby foods, bread and snacks. Although there is still no clarity about the risks associated with the current intake levels of dietary furan, to limit the furan occurrence in foods may be considered as a challenge in the prevention of human diseases as cancer. Considering that heat processed starchy products are characterized by their high worldwide consumption, we decided to dig into the mechanisms that would define their final content of furan. The present study explored the effect of heating conditions (frying and baking) and ascorbic acid concentration over furan occurrence in a starchy model system. Two different formulations of wheat flour dough (WF: wheat flour and WF-AA: wheat flour and ascorbic acid) were prepared with a 40 % of moisture (wb). Then, dough were cut in circle chips (40 mm of diameter ; 2.3 mm of thickness) which were fried and baked at 170°C and 200°C for 5, 7 and 9 minutes. Furan contents of heat processed products were quantified by GC-MS. WF fried products contained higher furan levels than baked ones for all different processing times (e.g. 97 % higher furan in 5 minutes fried chips). For the case of WF-AA chips baking produced more furan compared to the frying (e.g. 58 % higher furan in 7 minutes baked chips). For all process conditions ascorbic acid addition produced an increase in furan levels (?17%-58% in frying and ?74-98 % in baking). As for Maillard reactions in general, for all samples, an increase in furan level was observed when the moisture content decreased. Additionally, in fried products furan level was directly proportional to their oil uptake. We conclude that for the present model conditions, ascorbic acid improves the furan generation, having a stronger effect in baked products. We also propose that while lipid oxidation has been considered as one of main furan generation routes, for this particular case, it should not have a greater influence over furan formation; since frying experiments were realized with commercial sunflower oil with added antioxidant. Finally, considering that furan is an unpolar compound, for fried product the oil uptake may be responsible for the higher furan retention.

  2. Stability in fish feed and bioavailability to rainbow trout of two ascorbic acid forms

    OpenAIRE

    Skelbaek, T.; Andersen, Niels Gerner; Winning, M.; Westergaard, S.

    2011-01-01

    The stability in warm pelleted fish feed and the bioavailability to rainbow trout of crystalline ascorbic acid (AA) and a synthetic polymer-coated AA product (PCAA) were compared. The AA loss during pelleting was 29% for crystalline AA and 19% for PCAA. After 6 weeks at room temperature 73% of PCAA was still retained whereas less than 10% of crystalline AA was left. Rainbow trout were deprived of AA for 8 weeks, and then supplemented with AA from crystalline AA and PCAA, respectively. At the ...

  3. Electrocatalysis and Determination of Ascorbic Acid Through Graphite Paste Electrode Modified With Iron Nitroprusside

    OpenAIRE

    Devaney R. do Carmo; Ricardo M. da Silva; NELSON R. STRADIOTTO

    2004-01-01

    Iron nitroprusside, Fe(II)NP was incorporated into a carbon paste electrode and the electrochemical studies were performed by cyclic voltammetry. The cyclic voltammogram of the modified electrode, Fe(II)NP showed two redox couples ( E½ox)1 = 0.24 and (E½ox)2 = 0.85 V vs. SCE attributed to Fe(II)/Fe(III) and Fe(II)(CN)5NO / Fe(III)(CN)5NO, respectively. The redox couple at (E½ox)1 = 0.24 V presents an electrocatalytic response for ascorbic acid. The modified paste electrode exhibits a decrease...

  4. Silver Colloid Synthesis in Linear and Branched Anionic Polymer Matrices by Using Ascorbic Acid as Reductant

    Directory of Open Access Journals (Sweden)

    Korychenska O.

    2013-09-01

    Full Text Available Silver colloids were synthesized in linear and branched anionic polymer matrices at different pH reducing by ascorbic acid. The template role of the host polymers in anionic form was studied at pH = 7 and pH = 12. Linear Polyacrylamide and star-like copolymers Dextran-graft-Polyacrylamide after alkaline hydrolysis were used as matrices. Silver colloids were studied by UV-Vis spectrophotometry just after synthesis and in 3 months. It is shown that branched polymer matrices are more efficient in comparison with linear one for in situ silver nanoparticle synthesis. The pH value affects the process of formation was investigated.

  5. Ascorbic acid and citric flavonoids for broilers under heat stress: effects on performance and meat quality

    OpenAIRE

    JEM Peña; Vieira SL; López, J.; RN Reis; Barros, R.; FVF Furtado; PX Silva

    2008-01-01

    The aim of this study was to evaluate the effects of increasing doses of ascorbic acid (AA) and citric flavonoids (quercetin and rutin) on the performance and meat quality characteristics of broilers submitted to cyclic heat stress. Four-hundred one-day-old female Ross 308 were housed in 40 battery cages a in temperature controlled room. Treatments consisted of 0, 250, 500, and 1000 g/ton on of AA + citric flavonoids. Birds were fed ad libitum until 32 day of age. Beginning on day 14 post-hat...

  6. Adaptive alterations in the fatty acids composition under induced oxidative stress in heavy metal-tolerant filamentous fungus Paecilomyces marquandii cultured in ascorbic acid presence.

    Science.gov (United States)

    S?aba, Miros?awa; Gajewska, Ewa; Bernat, Przemys?aw; Fornalska, Magdalena; D?ugo?ski, Jerzy

    2013-05-01

    The ability of the heavy metal-tolerant fungus Paecilomyces marquandii to modulate whole cells fatty acid composition and saturation in response to IC50 of Cd, Pb, Zn, Ni, and Cu was studied. Cadmium and nickel caused the most significant growth reduction. In the mycelia cultured with all tested metals, with the exception of nickel, a rise in the fatty acid unsaturation was noted. The fungus exposure to Pb, Cu, and Ni led to significantly higher lipid peroxidation. P. marquandii incubated in the presence of the tested metals responded with an increase in the level of linoleic acid and escalation of electrolyte leakage. The highest efflux of electrolytes was caused by lead. In these conditions, the fungus was able to bind up to 100 mg g(-1) of lead, whereas the content of the other metals in the mycelium was significantly lower and reached from 3.18 mg g(-1) (Cu) to 15.21 mg g(-1) (Zn). Additionally, it was shown that ascorbic acid at the concentration of 1 mM protected fungal growth and prevented the changes in the fatty acid composition and saturation but did not alleviate lipid peroxidation or affect the increased permeability of membranes after lead exposure. Pro-oxidant properties of ascorbic acid in the copper-stressed cells manifested strong growth inhibition and enhanced metal accumulation as a result of membrane damage. Toxic metals action caused cellular modulations, which might contributed to P. marquandii tolerance to the studied metals. Moreover, these changes can enhance metal removal from contaminated environment. PMID:23132407

  7. Betalain, Acid ascorbic, phenolic contents and antioxidant properties of purple, red, yellow and white cactus pears.

    Science.gov (United States)

    Sumaya-Martínez, María Teresa; Cruz-Jaime, Sandra; Madrigal-Santillán, Eduardo; García-Paredes, Juan Diego; Cariño-Cortés, Raquel; Cruz-Cansino, Nelly; Valadez-Vega, Carmen; Martinez-Cardenas, Leonardo; Alanís-García, Ernesto

    2011-01-01

    Commercialization of cactus pears based on their antioxidant properties can generate competitive advantages, and these can turn into business opportunities and the development of new products and a high-value ingredient for the food industry. This work evaluated the antioxidant activities (1,1-diphenyl-2-picrylhydrazyl radical-scavenging, protection against oxidation of a ?-carotene-linoleic acid emulsion, and iron (II) chelation), the content of total phenolic compounds, ascorbic acid, betacyanin, betaxanthin and the stability of betacyanin pigments in presence of Cu (II)-dependent hydroxyl radicals (OH•), in 18 cultivars of purple, red, yellow and white cactus pear from six Mexican states. Our results indicated that the antiradical activities from yellow and white cactus pear cultivars were not significantly different (p < 0.05) and were lower than the average antiradical activities in red and purple cultivars. The red cactus pear from the state of Zacatecas showed the highest antioxidant activity. The free radical scavenging activity for red cactus pears was significantly correlated (p < 0.05) to the concentration of total phenolic compounds (R(2) = 0.90) and ascorbic acid (R(2) = 0.86). All 18 cultivars of cactus pears studied showed significant chelating activity of ferrous ions. The red and purple cactus pears showed a great stability when exposed to OH•. PMID:22072899

  8. Betalain, Acid Ascorbic, Phenolic Contents and Antioxidant Properties of Purple, Red, Yellow and White Cactus Pears

    Directory of Open Access Journals (Sweden)

    Leonardo Martinez-Cardenas

    2011-09-01

    Full Text Available Commercialization of cactus pears based on their antioxidant properties can generate competitive advantages, and these can turn into business opportunities and the development of new products and a high-value ingredient for the food industry. This work evaluated the antioxidant activities (1,1-diphenyl-2-picrylhydrazyl radical-scavenging, protection against oxidation of a ?-carotene-linoleic acid emulsion, and iron (II chelation, the content of total phenolic compounds, ascorbic acid, betacyanin, betaxanthin and the stability of betacyanin pigments in presence of Cu (II-dependent hydroxyl radicals (OH•, in 18 cultivars of purple, red, yellow and white cactus pear from six Mexican states. Our results indicated that the antiradical activities from yellow and white cactus pear cultivars were not significantly different (p < 0.05 and were lower than the average antiradical activities in red and purple cultivars. The red cactus pear from the state of Zacatecas showed the highest antioxidant activity. The free radical scavenging activity for red cactus pears was significantly correlated (p < 0.05 to the concentration of total phenolic compounds (R2 = 0.90 and ascorbic acid (R2 = 0.86. All 18 cultivars of cactus pears studied showed significant chelating activity of ferrous ions. The red and purple cactus pears showed a great stability when exposed to OH•.

  9. Long-term ascorbic acid administration causes anticonvulsant activity during moderate and long-duration swimming exercise in experimental epilepsy.

    Science.gov (United States)

    Tutkun, Erkut; Arslan, Gokhan; Soslu, Recep; Ayyildiz, Mustafa; Agar, Erdal

    2015-01-01

    The benefits of regular exercise on brain health are undeniable. Long-term exercise increases the production of reactive oxygen species in brain. Therefore, athletes often consume antioxidant supplements to remedy exercise-related damage and fatigue during exercise. The aim of this study is to evaluate the role of ascorbic acid in the effects of different intensities of swimming exercise on the brain susceptibility to experimental epilepsy in rats. Ascorbic acid was administered intraperitoneally (ip) during three different swimming exercise programme for 90 days (15 min, 30 min, 90 min/day). The anticonvulsant activity regarding the frequency of epileptiform activity appeared in the 80 min after 500 units intracortical penicillin injection in 30 min and 90 min/day exercise groups. The administration of ascorbic acid (100 mg/kg, ip) did not alter the anticonvulsant properties seen in the in short-duration (15 min/day) swimming exercise group. The amplitude of epileptiform activity also became significant in the 110 and 120 min after penicillin injection in the moderate (30 min/day) and long duration (60 min/day) groups, respectively. The results of the present study provide electrophysiologic evidence that long-term administration of ascorbic acid causes anticonvulsant activities in the moderate and long-duration swimming exercise. Antioxidant supplementation such as ascorbic acid might be suggested for moderate and long-duration swimming exercise in epilepsy. PMID:26232995

  10. Protective Effects of Extract from Dates (Phoenix Dactylifera L. and Ascorbic Acid on Thioacetamide-Induced Hepatotoxicity in Rats

    Directory of Open Access Journals (Sweden)

    Mohamed Bastway Ahmed

    2008-01-01

    Full Text Available The ameliorative activity of aqueous extract of the flesh of dates (Phoenix dactylifera L. and ascorbic acid on thioacetamide-induced hepatotoxicity was studied in rats. Sixty male rats were divided into six equal groups of 10. Two groups were controls, one treated with thioacetamide and one with only distilled water. Two groups received extract of flesh Phoenix dactylifera and intraperitoneal (IP thioacetamide (400 mg/kg either before or after administration of flesh extract. Two groups received ascorbic acid and intraperitoneal (IP thioacetamide (400 mg/kg b.wt. either before or after administration of ascorbic acid. Liver damage was assessed by estimation of plasma concentration of bilirubin and enzymes activities of aspartate aminotransferase (AST, alanine aminotransferase ( ALT, lactate dehydrogenase (LDH, γ glutamyl transferase and alkaline phosphatase and serum alpha fetoprotein and serum total testosterone. Treatment with aqueous extract of date flesh or by ascorbic acid significantly reduced thioacetamide-induced elevation in plasma bilirubin concentration and enzymes. This study suggests that thioacetamide-induced liver damage in rats can be ameliorated by administration of extract of date flesh and ascorbic acid.

  11. Modelling the effects of transglutaminase and L-ascorbic acid on substandard quality wheat flour by response surface methodology

    Directory of Open Access Journals (Sweden)

    Šimurina Olivera D.

    2014-01-01

    Full Text Available In recent decade, there have been observed extreme variations in climatic conditions which in combination with inadequate agro techniques lead to decreased quality of mercantile wheat, actally flour. The application of improvers can optimise the quality of substandard wheat flour. This paper focuses to systematic analysis of individual and interaction effects of ascorbic acid and transglutaminase as dough strengthening improvers. The effects were investigated using the Response Surface Methodology. Transglutaminase had much higher linear effect on the rheological and fermentative properties of dough from substandard flour than L-ascorbic acid. Both transglutaminase and L-ascorbic acid additions had a significant linear effect on the increase of bread specific volume. Effects of transglutaminase and ascorbic acid are dependent on the applied concentrations and it is necessary to determine the optimal concentration in order to achieve the maximum quality of the dough and bread. Optimal levels of tested improvers were determined using appropriate statistical techniques which applied the desirability function. It was found that the combination of 30 mg/kg of transglutaminase and 75.8 mg/kg of L-ascorbic acid achieved positive synergistic effect on rheological and fermentative wheat dough properties, as well on textural properties and specific volume of bread made from substandard quality flour.

  12. Ascorbic acid suppresses endotoxemia and NF-?B signaling cascade in alcoholic liver fibrosis in guinea pigs: A mechanistic approach

    International Nuclear Information System (INIS)

    Alcohol consumption increases the small intestinal bacterial overgrowth (SIBO) and intestinal permeability of endotoxin. The endotoxin mediated inflammatory signaling plays a major role in alcoholic liver fibrosis. We evaluated the effect of ascorbic acid (AA), silymarin and alcohol abstention on the alcohol induced endotoxemia and NF-?B activation cascade pathway in guinea pigs (Cavia porcellus). Guinea pigs were administered ethanol at a daily dose of 4 g/kg b.wt for 90 days. After 90 days, ethanol administration was stopped. The ethanol treated animals were divided into abstention, silymarin (250 mg/kg b.wt) and AA (250 mg/kg b.wt) supplemented groups and maintained for 30 days. The SIBO, intestinal permeability and endotoxin were significantly increased in the ethanol group. The mRNA expressions of intestinal proteins claudin, occludin and zona occludens-1 were significantly decreased in ethanol group. The mRNA levels of inflammatory receptors, activity of IKK? and the protein expressions of phospho-I?B?, NF-?B, TNF-?, TGF-?1 and IL-6 were also altered in ethanol group. The expressions of fibrosis markers ?-SMA, ?1 (I) collagen and sirius red staining in the liver revealed the induction of fibrosis. But the supplementation of AA could induce greater reduction of ethanol induced SIBO, intestinal barrier defects, NF-?B activation and liver fibrosis than silymarin. The possible mechanism may be the inhibitory effect of AA on SIBO, intestinal barrier defect and IKK?, which decreased the activation of NF-?B and synthesis of cytokines. This might have led to suppression of HSCs activation and liver fibrosis. - Highlights: • Alcohol increases intestinal bacterial overgrowth and permeability of endotoxin. • Endotoxin mediated inflammation plays a major role in alcoholic liver fibrosis. • Ascorbic acid reduces endotoxemia, NF-?B activation and proinflammatory cytokines. • AA's action is by inhibition of SIBO, IKK? and alteration of intestinal permeability. • This might have led to suppression of HSCs activation and liver fibrosis

  13. Ascorbic acid suppresses endotoxemia and NF-?B signaling cascade in alcoholic liver fibrosis in guinea pigs: A mechanistic approach

    Energy Technology Data Exchange (ETDEWEB)

    Abhilash, P.A.; Harikrishnan, R.; Indira, M., E-mail: indiramadambath@gmail.com

    2014-01-15

    Alcohol consumption increases the small intestinal bacterial overgrowth (SIBO) and intestinal permeability of endotoxin. The endotoxin mediated inflammatory signaling plays a major role in alcoholic liver fibrosis. We evaluated the effect of ascorbic acid (AA), silymarin and alcohol abstention on the alcohol induced endotoxemia and NF-?B activation cascade pathway in guinea pigs (Cavia porcellus). Guinea pigs were administered ethanol at a daily dose of 4 g/kg b.wt for 90 days. After 90 days, ethanol administration was stopped. The ethanol treated animals were divided into abstention, silymarin (250 mg/kg b.wt) and AA (250 mg/kg b.wt) supplemented groups and maintained for 30 days. The SIBO, intestinal permeability and endotoxin were significantly increased in the ethanol group. The mRNA expressions of intestinal proteins claudin, occludin and zona occludens-1 were significantly decreased in ethanol group. The mRNA levels of inflammatory receptors, activity of IKK? and the protein expressions of phospho-I?B?, NF-?B, TNF-?, TGF-?{sub 1} and IL-6 were also altered in ethanol group. The expressions of fibrosis markers ?-SMA, ?{sub 1} (I) collagen and sirius red staining in the liver revealed the induction of fibrosis. But the supplementation of AA could induce greater reduction of ethanol induced SIBO, intestinal barrier defects, NF-?B activation and liver fibrosis than silymarin. The possible mechanism may be the inhibitory effect of AA on SIBO, intestinal barrier defect and IKK?, which decreased the activation of NF-?B and synthesis of cytokines. This might have led to suppression of HSCs activation and liver fibrosis. - Highlights: • Alcohol increases intestinal bacterial overgrowth and permeability of endotoxin. • Endotoxin mediated inflammation plays a major role in alcoholic liver fibrosis. • Ascorbic acid reduces endotoxemia, NF-?B activation and proinflammatory cytokines. • AA's action is by inhibition of SIBO, IKK? and alteration of intestinal permeability. • This might have led to suppression of HSCs activation and liver fibrosis.

  14. Effects of ascorbic acid enrichment by immersion of rainbow trout (Oncorhynchus mykiss, Walbaum 1792) eggs and embryos

    Science.gov (United States)

    Falahatkar, B.; Dabrowski, K.; Arslan, M.; Rinchard, J.

    2006-01-01

    This study was conducted to examine the effects of different forms and concentrations of ascorbic acid (vitamin C), and different enrichment times (24 and 48 h post ovulation) on egg, embryo and alevin ascorbate concentrations and survival of rainbow trout (enrichment was at the ova stage). In experiments 1 and 2, fertilized eggs were immersed in water containing ascorbate at 0 (control), 100, 1000 mg L-1 l-ascorbic acid (AA) and 2000 mg L -1 l-ascorbyl monophosphate (AP). In experiment 3, 0 (control), 500 and 1000 mg L-1 AA neutralized (N) with NaOH, 1000 mg L-1 AA non-neutralized (NN), 1000 and 2000 mg L-1 AP immersions were used. The mean total ascorbic acid (TAA) and dehydroascorbic acid (DHA) concentrations were measured before fertilization, at 3 and 24 h after fertilization, at the eyed stage, and in hatched alevins. We observed significant differences in TAA concentration at different immersion levels at 3 and 24 h after fertilization. Survival decreased significantly depending on the level of vitamin C, pH of the solutions and immersion time. We suggest that when broodstock rainbow trout do not have enough vitamin C in their ovaries, immersion of eggs in 1000 mg L-1 of neutralized AA may be useful. ?? 2006 Blackwell Publishing Ltd.

  15. Hepato-protective effect of ascorbic acid on oxidative stress in mic exposed to cypermethrin

    International Nuclear Information System (INIS)

    To evaluate protective effect of ascorbic acid on liver parameters in mice exposed to Cypermethrin. Study Design:Laboratory based randomized control trial. Place and Duration of Study: Research was conducted in Army Medical College's biochemistry and molecular biology department in association with department of pathology, Army Medical College, Rawalpindi and National Institute of Health, Islamabad, Pakistan from 19 May 2013 to 17 June 2013. Material and Methods: Thirty albino mice of Balb/C strain weighing 40-45g were randomly divided into three groups. Each group comprised 10 mice. Control group A which received normal diet. Cypermethrin experimental group B received cypermethrin with normal diet experimental group C which received cypermethrin and vitamin C with normal diet. This process continued for 28 days. After this duration serum alanine aminotransferase (ALT) and serum aspartate aminotransferase (AST) values were determined. Results: Serum ALT and AST levels were significantly increased in group B as compared to group A (p< .001). ALT levels of group A and group C were insignificant (p= 0.473). AST levels of group A and C were significantly different (p< 0.01). Conclusion: Ascorbic acid can protect liver from Cypermethrininduced oxidative stress in mice. (author)

  16. Phenolic composition, ascorbic acid content, and antioxidant capacity of Spanish jujube (Ziziphus jujube Mill.) fruits.

    Science.gov (United States)

    Wojdy?o, Aneta; Carbonell-Barrachina, Ángel A; Legua, Pilar; Hernández, Francisca

    2016-06-15

    The interest in Ziziphus jujube is growing because it is an excellent source of nutrients and phytochemicals, and can contribute to a healthy diet. Nutritional compounds (phenolic compounds and l-ascorbic acid), and antioxidant capacity of 4 Spanish jujube cultivars were studied. Polyphenols were identified by LC-MS-QTof and quantified by UPLC-PDA-FL. A total of 25 polyphenolic compounds were identified and classified as 10 flavan-3-ols, 13 flavonols, 1 flavanone, and 1 dihydrochalcone. The content of total polyphenols (TP) ranged from 1442 to 3432mg/100g dry matter (dm) in fruits of the cultivars 'DAT' and 'PSI', respectively. Flavan-3-ols, the major group of polyphenols in jujube represented ?92% of the TP content, whereas flavonols only amounted for about ?8% each. The content of l-ascorbic acid was very high and took values in the range of 387-555mg/100g fresh weight (fw). Some Spanish jujube cultivars, especially 'PSI' and 'MSI', may be selected to promote the growth of cultivars with valuable nutritional and phytochemical beneficial effects on human health. PMID:26868581

  17. Development of iodimetric redox method for routine estimation of ascorbic acid from fresh fruit and vegetables

    International Nuclear Information System (INIS)

    The iodimetric method (Im) is developed for rapid estimation of ascorbic acid from fresh fruit and vegetables. The efficiency of Im was compared with standard with standard dye method (Dm) utilizing a variety of model solutions and aqueous extracts from fresh fruit and vegetables of different colors. The Im presented consistently accurate and precise results from colorless to colored model solutions and from fruit/vegetable extracts with standard deviation (Stdev) in the range of +-0.013 - +-0.405 and +-0.019 - +-0.428 respectively with no significant difference between the replicates. The Dm worked also satisfactorily for colorless model solutions and extracts (Stdev range +-0.235 - +-0.309) while producing unsatisfactory results (+-0.464 - +-3.281) for colored counterparts. Severe discrepancies/ overestimates continued to pileup (52% to 197%) estimating the nutrient from high (3.0 mg/10mL) to low (0.5 mg/10mL) concentration levels, respectively. On the basis of precision and reliability, the Im technique is suggested for adoption in general laboratories for routine estimation of ascorbic acid from fruit and vegetables possessing any shade. (author)

  18. Visualization and analysis of the release mechanism of shellac coated ascorbic acid pellets.

    Science.gov (United States)

    Förmer, P; Theurer, C; Müller, A; Schmidt, P C

    2006-12-01

    Shellac coated sustained release ascorbic acid containing pellets were investigated using scanning electron microscopy in order to visualize the release mechanism and to establish a correlation to dissolution data. Scanning electron micrograph pictures revealed different drug release profiles of individual pellets. Single pellet dissolution measurements demonstrated that the release profile of the encapsulated dosage form, containing approximately 400 pellets per capsule, is a combination of different release profiles of all individual pellets. The release of ascorbic acid occurred only in some small spots on the surface area of the pellets and could be visualized by the reduction of silver ions from an aqueous silver nitrate solution. These spots could be identified as defects in the shellac sustained release film using scanning electron microscopy. In further trials, the dissolution rate of an individual pellet could be related to the number and dimension of holes in its membrane. In conclusion, the release is characterized by surface defects and scanning electron microscopy studies are a useful tool to get new information for a better understanding of the drug release. PMID:17283657

  19. Ascorbic acid stabilization of Re-188- and I-131-radiolabeled peptides for radiotherapy

    International Nuclear Information System (INIS)

    Re-188 labeled RC-160 [ cyclic NH2-(D)-Phe-Cys-Tyr-(D)-Trp-Lys-Val-Cys-Trp-NH2 ] cyclic NH is a radiolabeled somatostatin analog which is being explored for its potential as a local/regionally administered radiotherapeutic agent targeting somatostatin-receptor-positive tumors. The stability of 188Re-RC-160 towards radiolytic effects is a prerequisite for the success of such an approach. High radiation flux was found to result in radiolysis of the peptide, but addition of ascorbic acid to preparations of RC-160 and also somatostatin-14 was found to stabilize these peptides minimizing these radiolytic effects. Subsequent to ascorbic acid stabilization, 188Re-RC-160 was determined in vitro and in vivo to bind to somatostatin-receptor-positive cells (NCI-H69 human small cell lung carcinoma) but not to receptor-negative cells (Raji, Burkitt's lymphoma). The comparative binding of Re-188 labeled RC-160 or CTOP [ cyclic NH2-(D)-Phe-CysTyr-(D)-Trp-Orn-Thr-Pen-Thr-ol], a ?-opiod-receptor antagonist used as a negative control compound, was also determined in vitro and in vivo using NCI-H69 cells as targets. 188Re-RC-160 demonstrated a higher amount of net binding in vitro and in vivo compared to 188ReCTOP. (orig.)

  20. Ascorbic acid stabilization of Re-188- and I-131-radiolabeled peptides for radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Guhlke, S.; Sartor, J.; Bender, H.; Biersack, H.J. [Bonn Univ. (Germany). Dept. of Nuclear Medicine; Zamora, P.O. [Bonn Univ. (Germany). Dept. of Nuclear Medicine]|[RhoMed Inc., Albuquerque, NM (United States); Knapp, F.F. Jr. [Oak Ridge National Lab. (ORNL), TN (United States). Nuclear Medicine Group; Rhodes, B.A. [RhoMed Inc., Albuquerque, NM (United States)

    1997-12-31

    Re-188 labeled RC-160 [ cyclic NH{sub 2}-(D)-Phe-Cys-Tyr-(D)-Trp-Lys-Val-Cys-Trp-NH{sub 2} ] cyclic NH is a radiolabeled somatostatin analog which is being explored for its potential as a local/regionally administered radiotherapeutic agent targeting somatostatin-receptor-positive tumors. The stability of {sup 188}Re-RC-160 towards radiolytic effects is a prerequisite for the success of such an approach. High radiation flux was found to result in radiolysis of the peptide, but addition of ascorbic acid to preparations of RC-160 and also somatostatin-14 was found to stabilize these peptides minimizing these radiolytic effects. Subsequent to ascorbic acid stabilization, {sup 188}Re-RC-160 was determined in vitro and in vivo to bind to somatostatin-receptor-positive cells (NCI-H69 human small cell lung carcinoma) but not to receptor-negative cells (Raji, Burkitt`s lymphoma). The comparative binding of Re-188 labeled RC-160 or CTOP [ cyclic NH{sub 2}-(D)-Phe-CysTyr-(D)-Trp-Orn-Thr-Pen-Thr-ol], a {mu}-opiod-receptor antagonist used as a negative control compound, was also determined in vitro and in vivo using NCI-H69 cells as targets. {sup 188}Re-RC-160 demonstrated a higher amount of net binding in vitro and in vivo compared to {sup 188}ReCTOP. (orig.)

  1. Association of Lactobacillus crispatus with fructo-oligosaccharides and ascorbic acid in hydroxypropyl methylcellulose vaginal insert.

    Science.gov (United States)

    Vitali, Beatrice; Abruzzo, Angela; Parolin, Carola; Palomino, Rogers Alberto Ñahui; Dalena, Francesco; Bigucci, Federica; Cerchiara, Teresa; Luppi, Barbara

    2016-01-20

    The aim of this work was to develop a synbiotic vaginal insert containing the probiotic strain Lactobacillus crispatus BC5, the prebiotic substrate fructo-oligosaccharide and the antioxidant agent ascorbic acid, for the prophylaxis and therapy of vaginal infections. Mucoadhesive in situ gelling vaginal inserts based on hydroxypropyl methylcellulose were prepared by freeze-drying, stored at +2-8°C for 90 days and characterized in terms of technological and functional properties. Complete survival of L. crispatus BC5 was found immediately after insert preparation (96.08%) as well as after 90 days of storage (95.82%) in the vaginal inserts containing fructo-oligosaccharide, ascorbic acid and skimmed milk. Synbiotic inserts showed improved mucoadhesion ability (from three- to five-fold) with respect to a standard formulation based on hydroxypropyl methylcellulose alone. Moreover, inserts allowed to modulate lactobacilli release in virtue of the different amounts of fructo-oligosaccharide. Finally, antimicrobial activity was exerted by L. crispatus BC5 released from the vaginal formulation. PMID:26572459

  2. Antioxidant capacity and contents of phenols, ascorbic acid, ?-carotene and lycopene in lettuce

    Directory of Open Access Journals (Sweden)

    Zdravkovi? Jasmina M.

    2014-01-01

    Full Text Available The antioxidant activity of three lettuce varieties (Lactuca sativa L. Emerald, Vera and Neva, cultivated in two kinds of protected spaces, a glasshouse and a plastic greenhouse, under controlled conditions, was determined. The content of antioxidant compounds: total phenols, flavonoids, L-ascorbic acid, ß-carotene and lycopene, were determined in ethanolic extracts of the lettuce with spectrophotometric methods. The largest content of total phenols (78.98 ± 0.67 mg GAE/g of dry extract was found in ethanolic extract of the lettuce variety Neva cultivated in a plastic greenhouse, whereas the largest content of flavonoids (35.45 ± 0.95 mg RU/g of dry extract was displayed in the lettuce Emerald cultivated in a glasshouse. It was observed that the lettuce cultivated in the glasshouse contained a somewhat higher content of L-ascorbic acid than the lettuce same variety from plastic greenhouse. The content of lycopene in the examined lettuce is negligible, and the content of ß-carotene is low. On the other hand, the high content of phenolic components causes favourable antioxidant properties found in all varieties of examined lettuce. [Projekat Ministarstva nauke Republike Srbije, br. TR 31059: A new concept in breeding vegetable cultivars and hybrids designed for sustainable growing systems using biotechnological methods

  3. Iodine application increased ascorbic acid content and modified the vascular tissue in opuntia ficus-indica

    International Nuclear Information System (INIS)

    The objective of this study was to discern the effect of applying both iodide and iodate to Opuntia ficus indica irrigation. The effect of iodate (KIO/sub 3/, 10-4 M) and iodide (KI, 10-4 M) on plant growth, yield and morphology was studied. Experiments were carried in three samples under tunnel conditions. In the last sampling, iodine species (KIO/sub 3/, KI) caused a negative effect in biomass. The amount of ascorbic acid, however, was increased over 51% in both iodine treatments. Phosphorus (0.26%), iron (50 ppm), and magnesium (1402 ppm) increases were also observed with iodate treatment in the first sampling, and increases in potassium (46.8 ppm) were apparent in the second. Iodide treatment increased the amounts of copper (1.02 ppm) and manganese (32.80 ppm) in the first sampling. Iodate treatment modified the number of xylem vessels and increased both the mucilage area and amount of druses. In general this study shows that iodate increases the amount of ascorbic acid and the morphology of the vascular tissue. (author)

  4. Role of cellular antioxidants (glutathione and ascorbic acid) in the growth and development of wild carrot suspension cultures

    International Nuclear Information System (INIS)

    Determinations of endogenous glutathione (GSH), glutathione disulfide (GSSG), ascorbic acid (AA) and dehydroascorbic acid (DHA) in proliferating and developing wild carrot cultures showed that lower levels of GSH and AA were associated with developing cultures. The GSSG and DHA levels did not account for the changes in the levels of antioxidants between proliferating and developing cultures. Studies were designed to test an observed auxin (2,4-Dichlorophenoxyacetic acid, 2,4-D)-antioxidant association. Two fractions (embryo and less developed) were obtained by screening developed cultures which were previously grown in the presence of 14C-2, 4-D. The embryo fraction had a lower concentration of 14C than the less developed fraction, supporting the association, since the two fractions showed this relationship with respect to GSH and AA concentrations. Determinations of GSH and AA levels of cells grown in various concentrations of 2,4-D showed the association, decreases in the 2,4-D concentration correlated with decreases in the GSH and AA concentrations. The existence of a respiratory pathway involving GSSG reductase, DHA reductase, and AA oxidase was investigated to test whether inhibition of AA oxidase by 2,4-D could explain the auxin-antioxidant association; however, AA oxidase activity was not detected

  5. Effect of ascorbic acid on reduced glutathione level in arsenic-loaded isolated liver tissues of rat

    Directory of Open Access Journals (Sweden)

    Beauty Saha

    2006-12-01

    Full Text Available Isolated liver tissues of rat were loaded with trivalent arsenic and were exposed in presence and absence of ascorbic acid. The amount of reduced glutathione (GSH in normal liver tissue was 52.0 ? 0.2 ?g/g protein. Addition of arsenic to the tissues reduced the amount of GSH to 11.5 ? 0.3 ?g/g protein. But when the arsenic loaded liver tissues were incubated with ascorbic acid at the concentration of 20 ?g/ml, the amount of GSH was 14.2 ? 0.1 ?g/g protein. There was 22.6% increase of GSH level which was statistically significant (p<0.001 when compared with arsenic alone. This study suggests that ascorbic acid increased the GSH level in arsenic-treated rat's liver.

  6. The effect of ionizing radiations on the ascorbic acid content in the vitreous body of the rabbit

    International Nuclear Information System (INIS)

    The authors report on the destructive effect of ionised rays on the eye ball. The ascorbic acid content in the vitreous of rabbits subjected to radiation with cobalt 60 using Stallard applicators was determined. The left eye which served as the non-radiated partner eye of the test object was employed as a control. Attention is drawn to a certain amount of reduction of the ascorbic acid content in the vitreous which is indirectly proportional to the employed quality of the rays. The changes were similar in those eyes which were not directly subjected to radiation. There changes were however not so much pronounced. Attention is drawn to the important role of ascorbic acid in vitreous metabolism. The authors point out that radiation damage can be found even in the eye that is not directly subjected to radiation. (orig.)

  7. A novel method for the determination of ascorbic acid and antioxidant capacity in Opuntia ficus indica using in vivo microdialysis.

    Science.gov (United States)

    Pretti, L; Bazzu, G; Serra, P A; Nieddu, G

    2014-03-15

    A simple and rapid method was developed for in vivo simultaneous determination of ascorbic-acid and antioxidant capacity in microdialysates from cladodes of Opuntia ficus-indica (L.) Miller. The method is verified in water-stressed plants, as compared with a well-watered test controls. The microdialysis probe construction and insertion procedure was specifically developed to minimise the tissue trauma of the plant and to obtain optimal dialysis performance. Microdialysis was performed using a flow rate of 3 ?L/min and the samples were analysed by HPLC coupled to electrochemical detection of ascorbic-acid and DPPH-determined antioxidant capacity. Our data indicate exponential decay of the concentrations of the analysed compounds as a function of microdialysis sampling time. Water-stressed Opuntia show decreased ascorbic acid levels and increased the others antioxidants. PMID:24206696

  8. Effects of gamma irradiation and storage temperature on carotenoids and ascorbic acid content of mangoes on ripening

    International Nuclear Information System (INIS)

    Synthesis and accumulation of carotenoids in the flesh of Alphonso mangoes on ripening was found to be maximal in fruits stored at tropical ambient temperatures (280 to 320C). Gamma irradiation of preclimacteric fruits at 25 krad did not affect the formation of carotenoids. Storage of preclimacteric fruits either irradiated or unirradiated at 7 to 200C for 16 to 43 days caused a substantial reduction in carotenoid formation even when these fruits were subsequently ripened under optimal conditions. Regardless of storage temperature, carotenes always exceeded xanthophylls in the ripe fruits and, in general, irradiated fruits showed higher levels of carotenes in comparison with unirradiated samples. Ascorbic acid loss during ripening was maximum at ambient temperatures while lengthy storage at low temperatures caused a net increase in ascorbic acid levels. Irradiation seemed to accentuate the loss in ascorbic acid during ripening. (author)

  9. Calcium and ascorbic acid affect cellular structure and water mobility in apple tissue during osmotic dehydration in sucrose solutions.

    Science.gov (United States)

    Mauro, Maria A; Dellarosa, Nicolò; Tylewicz, Urszula; Tappi, Silvia; Laghi, Luca; Rocculi, Pietro; Rosa, Marco Dalla

    2016-03-15

    The effects of the addition of calcium lactate and ascorbic acid to sucrose osmotic solutions on cell viability and microstructure of apple tissue were studied. In addition, water distribution and mobility modification of the different cellular compartments were observed. Fluorescence microscopy, light microscopy and time domain nuclear magnetic resonance (TD-NMR) were respectively used to evaluate cell viability and microstructural changes during osmotic dehydration. Tissues treated in a sucrose-calcium lactate-ascorbic acid solution did not show viability. Calcium lactate had some effects on cell walls and membranes. Sucrose solution visibly preserved the protoplast viability and slightly influenced the water distribution within the apple tissue, as highlighted by TD-NMR, which showed higher proton intensity in the vacuoles and lower intensity in cytoplasm-free spaces compared to other treatments. The presence of ascorbic acid enhanced calcium impregnation, which was associated with permeability changes of the cellular wall and membranes. PMID:26575708

  10. Sol-gel process for preparing YBa2Cu4O8 precursors from Y, Ba, and Cu acidic acetates/ammonia/ascorbic acid systems

    International Nuclear Information System (INIS)

    Sols were prepared by addition of ammonia to acidic acetate solutions of Y3+, Ba2+, and Cu2+. Ascorbic acid was added to a part of the sol. The resultant sols were gelled to a shard, a film, or microspheres by evaporation at 60 C or by extraction of water from drops of emulsion suspended in 2-ethylhexanol-1. Addition of ethanol to the sols facilitated the formation of gel films, fabricated by a dipping technique, on glass or silver substrates. At 100 C, gels that were formed in the presence of ascorbic acid were perfectly amorphous, in contrast to the crystalline acetate gels. Conversion of the amorphous ascorbate gels to final products was easier than for the acetate gels. The quality of coatings prepared from ascorbate gels was superior to that of acetate gel coatings

  11. Modeling the combined effects of pH, temperature and ascorbic acid concentration on the heat resistance of Alicyclobacillus acidoterrestis.

    Science.gov (United States)

    Bahçeci, K Sava?; Acar, Jale

    2007-12-15

    In this study, thermal inactivation parameters (D- and z-values) of Alicyclobacillus acidoterrestris spores in McIlvaine buffers at different pH, apple juice and apple nectar produced with and without ascorbic acid addition were determined. The effects of pH, temperature and ascorbic acid concentration on D-values of A. acidoterrestris spores were also investigated using response surface methodology. A second order polynomial equation was used to describe the relationship between pH, temperature, ascorbic acid concentration and the D-values of A. acidoterrestris spores. Temperature was the most important factor on D-values, and its effect was three times higher than those of pH. Although the statistically significant, heat resistance of A. acidoterrestris spores was not so influenced from the ascorbic acid within the concentration studied. D-values in apple juice and apple nectars were higher than those in buffers as heating medium at similar pH. The D-values ranged from 11.1 (90 degrees C) to 0.7 min (100 degrees C) in apple juice, 14.1 (90 degrees C) to 1.0 min (100 degrees C) in apple nectar produced with ascorbic acid addition, and 14.4 (90 degrees C) to 1.2 min (100 degrees C) in apple nectar produced without ascorbic acid addition. However, no significant difference in z-values was observed among spores in the juices and buffers at different pH, and it was between 8.2 and 9.2 degrees C. The results indicated that the spores of A. acidoterrestris may survive in fruit juices and nectars after pasteurization treatment commonly applied in the food industry. PMID:17936391

  12. "Oral ascorbic acid in combination with beta blockers in prevention of atrial fibrillation after Coronary Artery Bypass Graft "

    Directory of Open Access Journals (Sweden)

    Mousavi M

    2007-04-01

    Full Text Available Background: Adrenergic beta antagonists are not sufficient to prevent atrial fibrillation after coronary artery bypass graft (CABG. This study was designed to evaluate the effect of ascorbic acid as an adjunct to beta-blockers in prevention of post-CABG atrial fibrillation Methods: Patients who were more than 50 years old and scheduled to undergo CABG were included if they were treated with beta-blockers at least 1 week before surgery. Patients with previous history of atrial fibrillation, AV block, heart rate <50 /min, end-stage renal disease, severe pulmonary or liver disease and those who were taking digoxin or class I and III anti-arrhythmics or had pacemakers were not included. Ascorbic acid group were prescribed 2 gm of ascorbic acid, the night before the surgery, and 1 gm twice daily for 5 days after surgery. Beta blockers continued in both group after surgery. Telemetry monitoring was performed in ICU and Holter monitoring was performed for 4 days. Results: Fifty patients completed the study as ascorbic acid and 50 as control group. The population was 60.19 ± 7.14 years old and 67% were male. The incidence of postoperative atrial fibrillation was 4% in the ascorbic acid group and 26% in control group (odds ratio=0.119, 95% confidence interval: 0.025 to 0.558, P=0.002 Conclusion: Ascorbic acid is well-tolerated, relatively safe and seems effective. Therefore it can be prescribed as an adjunct to beta-blockers for prophylaxis of post-CABG atrial fibrillation.

  13. Determining Total Phenolics, Anthocyanin Content and Ascorbic Acid Content in Some Plum Genotypes Grown in Ardahan Ecological Conditions

    Directory of Open Access Journals (Sweden)

    Z. T. ABACI

    2014-06-01

    Full Text Available In this study, total phenol content, total anthocyanin content, brix, pH, titrable acidity and total ascorbic acid content in the five plum genotypes cultivated in Ardahan City are determined and sustenance of the plums are revealed. Total phenol content was determined with folin-ciocalteu’s method, total anthocyanin content was determined with pH differential method and total ascorbic acid was determined with 2,6-dichlorophenolindophenol method.It is detected that the genotype with the highest brix content (%13.9 and lowest acidity (%0.98 is cancur, the genotype with the lowest brix content (%11 and highest acidity (%2.06 is wild plum, the genotype with the highest content of total anthocyanin, total phenolic substance and ascorbic acid is the wild plum and the genotype with the least content of these is the water plum. As a result of the study, it is revealed that the plum fruit has high levels of phenolic substance, anthocyanin and ascorbic acid content, so it has a high sustenance.

  14. l-dehydroascorbic acid can substitute l-ascorbic acid as dietary vitamin C source in guinea pigs.

    Science.gov (United States)

    Frikke-Schmidt, Henriette; Tveden-Nyborg, Pernille; Lykkesfeldt, Jens

    2016-04-01

    Vitamin C deficiency globally affects several hundred million people and has been associated with increased morbidity and mortality in numerous studies. In this study, bioavailability of the oxidized form of vitamin C (l-dehydroascorbic acid or DHA)-commonly found in vitamin C containing food products prone to oxidation-was studied. Our aim was to compare tissue accumulation of vitamin C in guinea pigs receiving different oral doses of either ascorbate or DHA. In all tissues tested (plasma, liver, spleen, lung, adrenal glands, kidney, muscle, heart, and brain), only sporadic differences in vitamin C accumulation from ascorbate or DHA were observed except for the lowest dose of DHA (0.25mg/ml in the drinking water), where approximately half of the tissues had slightly yet significantly less vitamin C accumulation than from the ascorbate source. As these results contradicted data from rats, we continued to explore the ability to recycle DHA in blood, liver and intestine in guinea pigs, rats and mice. These investigations revealed that guinea pigs have similar recycling capacity in red blood cells as observed in humans, while rats and mice do not have near the same ability to reduce DHA in erythrocytes. In liver and intestinal homogenates, guinea pigs also showed a significantly higher ability to recycle DHA compared to rats and mice. These data demonstrate that DHA in guinea pigs-as in humans-is almost as effective as ascorbate as vitamin C source when it comes to taking up and storing vitamin C and further suggest that the guinea pig is superior to other rodents in modeling human vitamin C homeostasis. PMID:26609560

  15. l-dehydroascorbic acid can substitute l-ascorbic acid as dietary vitamin C source in guinea pigs

    Directory of Open Access Journals (Sweden)

    Henriette Frikke-Schmidt

    2016-04-01

    Full Text Available Vitamin C deficiency globally affects several hundred million people and has been associated with increased morbidity and mortality in numerous studies. In this study, bioavailability of the oxidized form of vitamin C (l-dehydroascorbic acid or DHA—commonly found in vitamin C containing food products prone to oxidation—was studied. Our aim was to compare tissue accumulation of vitamin C in guinea pigs receiving different oral doses of either ascorbate or DHA. In all tissues tested (plasma, liver, spleen, lung, adrenal glands, kidney, muscle, heart, and brain, only sporadic differences in vitamin C accumulation from ascorbate or DHA were observed except for the lowest dose of DHA (0.25 mg/ml in the drinking water, where approximately half of the tissues had slightly yet significantly less vitamin C accumulation than from the ascorbate source. As these results contradicted data from rats, we continued to explore the ability to recycle DHA in blood, liver and intestine in guinea pigs, rats and mice. These investigations revealed that guinea pigs have similar recycling capacity in red blood cells as observed in humans, while rats and mice do not have near the same ability to reduce DHA in erythrocytes. In liver and intestinal homogenates, guinea pigs also showed a significantly higher ability to recycle DHA compared to rats and mice. These data demonstrate that DHA in guinea pigs—as in humans—is almost as effective as ascorbate as vitamin C source when it comes to taking up and storing vitamin C and further suggest that the guinea pig is superior to other rodents in modeling human vitamin C homeostasis.

  16. Modified gold electrodes based on thiocytosine/guanine-gold nanoparticles for uric and ascorbic acid determination

    International Nuclear Information System (INIS)

    The present paper describes the preparation of new modified surfaces for electrodes based on guanine/thiocytosine and gold nanoparticles. The gold nanoparticles were analyzed by UV–vis spectroscopy and transmission electron microscopy (TEM) and it was found that they have diameters between 30 and 40 nm. The layers were characterized by specular reflectance infrared spectroscopy (FTIR-RAS) and by atomic force microscopy (AFM). The thickness of layers was found to be approximately 30 nm for TC layers and 300 nm for GU layers. Every layer was characterized as electrochemical sensor (by cyclic voltammetry) both for uric acid and ascorbic acid determinations, separately and in their mixture. The modified sensors have good calibration functions with good sensitivity (between 1.145 and 1.406 mA cm?2/decade), reproducibility (thiocytosine (AuTC) and goldguanine (AuGU) layers

  17. The use of L-ascorbic acid in speciation of arsenic compounds in drinking water

    Directory of Open Access Journals (Sweden)

    Marjanović Nikola J.

    2009-01-01

    Full Text Available Arsenic speciation, besides total arsenic content determination, is very important in analysis of water, foodstuffs, and environmental samples, because of varying degrees of toxicity of different species. For such purpose hydride generation atomic absorption spectrometry can be used based on the generation of certain types of hydride, depending on the pH value and pretreatment in different reaction media. In this study, we have investigated the effect of L-ascorbic acid as the reaction medium as well as the pre-reducing agent in speciation of arsenic by hydride generation-atomic absorption spectrometry in order to determine monomethyl arsonic acid (MMA in the presence of inorganic forms of arsenic.

  18. Effect of pre and post treatment of ascorbic acid on wheat and maize seeds exposed to gamma radiation

    International Nuclear Information System (INIS)

    Seeds treated with and grown in the presence of ascorbic acid (AA) showed reduction in germination, seedling height and chlorophyll content. The LD50 of AA was found to be 0.7 M and 10 M for wheat and maize, respectively. Pre-irradiation treatment of the seeds with ascorbic acid showed relatively increased germination, seedling height and chlorophyll content compared to that of AA treatment after irradiation. The protection rendered by the pre-treatment of AA may be due to AA acting as a free radical scavenger and thus protecting seeds from radiation induced damages. (author)

  19. Dye-sensitized photopolymerization of N,N -methylenebisacrylamide by initiation with eosin-ascorbic acid system

    Indian Academy of Sciences (India)

    Parthasarathy Tigulla; Uma Vuruputuri

    2004-03-01

    The dye-sensitized photopolymerization of N,N'-methylenebisacrylamide (MBA) in aqueous medium initiated by eosin-ascorbic acid (AH2) was studied at 25°C. The polymerization takes place only at higher concentration of AH2 (> 10-3 mol/L) and its rate increases rapidly as [AH2] is increased. The rate of polymerization is proportional to [MBA] and [AH2]. Kinetic results indicate that semi-quinone (DH) dye radical and semi-oxidized form () of ascorbic acid are unable to initiate polymerization. Formation of H2O2 is proposed and confirmed. A suitable mechanism is proposed in accordance with experimental results obtained.

  20. Electrochemical Sensing of Dopamine, Uric Acid and Ascorbic Acid Using tRGO-TiO2 Nanocomposites.

    Science.gov (United States)

    Rajamani, A R; Kannan, Rajesh; Krishnan, Sruthy; Ramakrishnan, S; Raj, S Mohan; Kumaresan, D; Kothurkar, Nikhil; Rangarajan, Murali

    2015-07-01

    This work reports a graphene-based nonenzymatic electrochemical sensing platform for the detection of dopamine (DA), uric acid (UA), and ascorbic acid (AA). Graphene oxide, synthesized by modified Hummers method, was thermally reduced in an induction furnace at 200 °C in an Ar-H2 atmosphere to obtain thermally reduced graphene oxide (tRGO). Nanocomposites of tRGO-TiO2 were obtained by a hydrothermal method, and were characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and X-ray diffraction (XRD). FTIR spectra showed Ti-O-C peaks, indicating covalent linkage between the TiO2 nanoparticles and the reduced graphene oxide sheets. Glassy carbon electrode (GCE) was modified with the nanocomposite (tRGO-TiO2-GCE), and the modified electrode could detect dopamine (DA: 1 to 1000 µM), uric acid (UA: 1 to 900 µM), and ascorbic acid (AA: 10 to 1000 µM) in each other's presence over wide ranges, with adequate separation in peak potentials. Differential pulse voltammetry experiments yielded linear responses with sensitivities of 133.18, 33.96, and 155.59 µA mM(-1) cm(-2) for DA, UA, and AA, respectively. PMID:26373074

  1. Novel halogenated 3-deazapurine, 7-deazapurine and alkylated 9-deazapurine derivatives of L-ascorbic or imino-L-ascorbic acid: Synthesis, antitumour and antiviral activity evaluations.

    Science.gov (United States)

    Stipkovi? Babi?, Maja; Makuc, Damjan; Plavec, Janez; Martinovi?, Tamara; Kraljevi? Paveli?, Sandra; Paveli?, Krešimir; Snoeck, Robert; Andrei, Graciela; Schols, Dominique; Wittine, Karlo; Mintas, Mladen

    2015-09-18

    Keeping the potential synergy of biological activity of synthetic anomalous derivatives of deazapurines and l-ascorbic acid (l-AA) in mind, we have synthesized new 3-, 7- and 9-deazapurine derivatives of l-ascorbic (1-4, 8-10, 13-15) and imino-l-ascorbic acid (5-7, 11, 12, 16-19). These novel compounds were evaluated for their cytostatic and antiviral activity in vitro against a panel of human malignant tumour cell lines and normal murine fibroblasts (3T3). Among all evaluated compounds, the 9-deazapurine derivative of l-AA (13) exerted the most potent inhibitory activity on the growth of CEM/0 cells (IC50 = 4.1 ± 1.8 ?M) and strong antiproliferative effect against L1210/0 (IC50 = 4.7 ± 0.1 ?M) while the 9-deazahypoxanthine derivative of l-AA (15) showed the best effect against HeLa cells (IC50 = 5.6 ± 1.3 ?M) and prominent effect on L1210/0 (IC50 = 4.5 ± 0.5 ?M). Furthermore, the 9-deazapurine derivative disubstituted with two imino-l-AA moieties (18) showed the best activity against L1210/0 tumour cells (IC50 = 4.4 ± 0.3 ?M) and the most pronounced antiproliferative effects against MiaPaCa-2 cells (IC50 = 5.7 ± 0.2 ?M). All these compounds showed selective cytostatic effect on tumour cell lines in comparison with embryonal murine fibroblasts (3T3). When evaluating their antiviral activity, the 3-deazapurine derivative of l-AA (3) exhibited the highest activity against both laboratory-adapted strains of human cytomegalovirus (HCMV) (AD-169 and Davis) with EC50 values comparable to those of the well-known anti-HCMV drug ganciclovir and without cytotoxic effects on normal human embryonal lung (HEL) cells. PMID:26291038

  2. Corrosion behaviours of AISI 304 stainless steel and Inconel-600 in EDTA/citric acid/ascorbic acid base decontamination solution

    International Nuclear Information System (INIS)

    Corrosion behaviours of AISI 304 stainless steel (SS) and Inconel-600 in dilute EDTA/citric acid/ascorbic acid solution of pH = 2.8 have been studied at 95 .deg. C with electrochemical polarization, weight loss measurement and metallographic observation. Polarization curves on AISI 304 SS were very similar to those on Inconel-600 in all solutions except a slightly higher passive current density on Inconel-600. Anodic polarization curves on AISI 304 SS and Inconel-600 in EDTA/citric acid mixture were also similar to those in EDTA solution. A passive region was found over the range of potential from-300 mV to 400 mV in EDTA solution as well as in EDTA/citric acid mixture. The passive current density in EDTA solution and in EDTA/citric acid mixture dose not depend on both kinds and concentration of chemicals in the experimental range. In case of EDTA/ascorbic acid mixture, the anodic current density was exactly the same with that in EDTA/citric acid mixture at potential below 100 mV. The higher anodic current density in EDTA/ascorbic acid mixture than in EDTA/citric acid mixture, however, was observed at potential above 100 mV. The metal oxidation current density calculated from weight loss at 400 mV in EDTA/ascorbic acid mixture was almost equal to that in EDTA/citric acid mixture. And anodic oxidation of chemicals on Pt increased with a sequence of citric acid, EDTA and ascorbic acid. So the higher anodic current in EDTA/ascorbic acid mixture than in EDTA/citric acid mixture was due to ascorbic acid oxidation. Those results indicated that EDTA, citric acid and ascorbic acid have no influence on corrosion behaviours of AISI 304 SS and Inconel-600 in the passive region. In all solutions passive current density was about 3 ? 5 ? A/cm2, and corrosion current density was about 1 ? 5 ? A. No pitting and intergranular corrosion were observed over the range of potential from 300 mV to 400 mV

  3. Mechanism of degradation and discoloration reaction of L-ascorbic acid

    International Nuclear Information System (INIS)

    The mechanisms of decomposition and coloration reaction of L-ascorbic acid are reviewed. At the initial stage of the decomposition, it can be classified roughly into oxidative and non-oxidative processes of decomposition. ASA forms furfural by being heated and decomposed in strong acid. The mechanism of the production of furfural at varying pH in acidic region was discussed. Furfural was produced through the enol form of 3-deoxy-L-pentosulose(3DP). 3DP seemed to be produced by two different routes: the one route consists of successive reactions from ASA through lactone ring-opening, dehydration, decarboxylation, to 3DP, and the other consists of reactions from the 3-keto form of ASA, through lactone ring-opening, decarboxylation, and dehydration, to the enol form of 3DP. ASA is easily reduced and decomposed through dehydro-ASA(DHA) by the presence of an oxidizing agent. The decomposition of DHA is discussed in cases of the systems of DHA alone, DHA and ?-aminoacid, and DHA and amine. DHA was decomposed by the same reaction scheme as the decomposition of ASA and yielded 2-furoic acid. In the presence of an amino acid, DHA was decomposed by the Strecker decomposition, and yielded a red compound and a radical. In the presence of an amine, the discoloration reaction seemed to take place through radical reaction mechanism. The coloration reaction of ASA occurs in an acidic medium, and is accelerated by the oxidative process of decomposition. (Nishino, S.)

  4. Fabrication and characterisation of high performance polypyrrole modified microarray sensor for ascorbic acid determination

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •Gold microelectrode array (Au/MEA) with electrode of 12 ?m diameter was fabricated by photolithography technique. •Subsequently, polypyrrole (Ppy) modified gold microarrays sensor (Ppy/Au/MEA) was prepared. •Ppy/Au/MEA used for ascorbic acid determination in the presence of different neurotransmitters. •The micro array exhibited wide linear range, very high sensitivity and very low LOD than the earlier reports. •It was used successfully to test ascorbic acid in different types real samples. -- Abstract: In this study, gold microelectrode array (Au/MEA) with electrode of 12 ?m diameter was fabricated by photolithography technique. Subsequently, polypyrrole (Ppy) modified gold microarrays sensor (Ppy/Au/MEA) was prepared by cyclic voltammetry technique. The deposition potential range and number of cycles were optimised in order to get optimum thickness of Ppy film. Scanning Electron Microscope and Atomic Force Microscope investigations reveal that Ppy coating formed at 3 cycles is porous with thickness of 1.5 ?m which exhibiting high catalytic current for ascorbic acid (AA) in square wave technique (SWV). In contrast to earlier sensors designs, these Ppy/Au/MEA sensors exhibits lower detection limit (LOD) of 10 nm towards AA at physiological conditions. It also exhibits enhanced sensitivity (2.5 mA cm?2 mM?1) and long range of linear detection limit from 10 nm to 2.8 mM. In the same way, polypyrrole modified macro Au (Ppy/Au/MA) biosensor was also fabricated and its electro catalytic property towards AA was compared with that of Ppy/Au/MEA. The Ppy/Au/MA exhibits sensitivity of only 0.27 mA cm?2 mM?1, LOD of 5 ?M and linear range of 10 ?M to 2.2 mM. Hence, our investigations indicate that the Ppy/Au/MEA could serve as highly sensitive sensor for AA than any of the earlier designs. So, the Ppy/Au/MEA electrode was utilised for determination AA in a wide variety of real samples

  5. Fabrication and characterisation of high performance polypyrrole modified microarray sensor for ascorbic acid determination

    Energy Technology Data Exchange (ETDEWEB)

    Samseya, J. [Alagappa University, Karaikudi, Tamil Nadu (India); Srinivasan, R., E-mail: sivarunjan@gmail.com [Central Electro Chemical Research Insititute, Karaikudi, Tamil Nadu (India); Chang, Yu-Tsern; Tsao, Cheng-Wen [Department of Cosmetic Applications, Taoyuan Innovation Institute of Technology, Taiwan (China); Vasantha, V.S. [Madurai Kamaraj University, Madurai, Tamil Nadu (India)

    2013-09-02

    Graphical abstract: -- Highlights: •Gold microelectrode array (Au/MEA) with electrode of 12 ?m diameter was fabricated by photolithography technique. •Subsequently, polypyrrole (Ppy) modified gold microarrays sensor (Ppy/Au/MEA) was prepared. •Ppy/Au/MEA used for ascorbic acid determination in the presence of different neurotransmitters. •The micro array exhibited wide linear range, very high sensitivity and very low LOD than the earlier reports. •It was used successfully to test ascorbic acid in different types real samples. -- Abstract: In this study, gold microelectrode array (Au/MEA) with electrode of 12 ?m diameter was fabricated by photolithography technique. Subsequently, polypyrrole (Ppy) modified gold microarrays sensor (Ppy/Au/MEA) was prepared by cyclic voltammetry technique. The deposition potential range and number of cycles were optimised in order to get optimum thickness of Ppy film. Scanning Electron Microscope and Atomic Force Microscope investigations reveal that Ppy coating formed at 3 cycles is porous with thickness of 1.5 ?m which exhibiting high catalytic current for ascorbic acid (AA) in square wave technique (SWV). In contrast to earlier sensors designs, these Ppy/Au/MEA sensors exhibits lower detection limit (LOD) of 10 nm towards AA at physiological conditions. It also exhibits enhanced sensitivity (2.5 mA cm{sup ?2} mM{sup ?1}) and long range of linear detection limit from 10 nm to 2.8 mM. In the same way, polypyrrole modified macro Au (Ppy/Au/MA) biosensor was also fabricated and its electro catalytic property towards AA was compared with that of Ppy/Au/MEA. The Ppy/Au/MA exhibits sensitivity of only 0.27 mA cm{sup ?2} mM{sup ?1}, LOD of 5 ?M and linear range of 10 ?M to 2.2 mM. Hence, our investigations indicate that the Ppy/Au/MEA could serve as highly sensitive sensor for AA than any of the earlier designs. So, the Ppy/Au/MEA electrode was utilised for determination AA in a wide variety of real samples.

  6. Serum Angiotensin Converting Enzyme Activity, Total Antioxidants and Ascorbic Acid in Iranian Patients with Coronary Artery Disease

    Directory of Open Access Journals (Sweden)

    F. Ghazi

    2009-01-01

    Full Text Available Angiotensin-Converting Enzyme (ACE is a dipeptidyl carboxypeptidase (EC: 3.4.15.1 that catalyzes the conversion of angiotensin I to the potent vasoconstrictor angiotensin II. Angiotesin II is responsible for an increase in blood pressure and maintenance of hypertension through the stimulation of oxidative stress. The relationship between Coronary Artery Disease (CAD, Angiotensin-Converting Enzyme (ACE activity, ascorbic acid and serum antioxidant status in patients with coronary artery disease. A group of 65 patients with angiographically defined Coronary Artery Disease (CAD and 60 normal control subjects were examined. The activity of Angiotensin-Converting Enzyme (ACE was determined by the reversed-phase High Performance Liquid Chromatography (HPLC to separate and quantify Hippuryl-Histidyl-Leucin (HHL and Hippuric Acid (HA. Ferric Reducing Ability of Plasma (FRAP Assay as a measure of antioxidant power was used. Serum ascorbic acid concentration was determined photometrically. The results demonstrated significant differences in ACE activity, antioxidant and ascorbic acid between CAD cases and normal controls. Increased levels of ACE activity in serum have been related to coronary artery disease. Serum ascorbic acid concentration (25.6±3.8 mg dL-1 and total antioxidant capacity (475.5±18.51 ?M L-1 were significantly (p<0.05 decreased in CAD patients compared with controls.

  7. Determination of Ascorbic Acid Content of Some Fruit Juices and Wine by Voltammetry Performed at Pt and Carbon Paste Electrodes

    Directory of Open Access Journals (Sweden)

    Aurel Pisoschi

    2011-02-01

    Full Text Available A method was developed for assessing ascorbic acid concentration in fruit juices and wine by differential pulse voltammetry. The oxidation peak for ascorbic acid occurs at about 530 mV (versus SCE on a Pt strip working electrode and at about 470 mV on a carbon paste working electrode. The influence of the operational parameters like the pulse amplitude and the pulse period on the analytical signal was investigated. The obtained calibration graph shows a linear dependence between the peak height and ascorbic acid concentration within the range 0.31-20 mM with a Pt working electrode, and within the range 0.07-20 mM with a carbon paste working electrode. The equation of the calibration graph was y = 21.839x + 35.726, r2 = 0.9940, when a Pt strip electrode was used (where y represents the value of the current intensity measured for the peak height, expressed as µA and x the analyte concentration, as mM. R.S.D. = 2.09%, n = 10, Cascorbic acid = 2.5 mM. The equation of the calibration graph was y = 3.4429x + 5.7334, r2 = 0.9971, when a carbon paste electrode was used (where y represents the value of intensity measured for the peak height, expressed as µA and x the analyte concentration, as mM. R.S.D. = 2.35%, n = 10, Cascorbic acid = 2.5 mM. The developed method was applied to ascorbic acid assessment in fruit juices and wine. The ascorbic acid content determined ranged between 6.83 mg/100 mL juice for soft drinks (Fanta Madness and 54.74 mg/100 mL for citrus (lemon juices obtained by squeezing fruit. Different ascorbic acid concentrations (from standard solutions were added to the analysed samples, the degree of recovery being comprised between 94.74 and 104.97%. The results of ascorbic acid assessment by differential pulse voltammetry were compared with those obtained by cyclic voltammetry. The results obtained by the two methods were in good agreement.

  8. A sensor of a polyoxometalate and Au–Pd alloy for simultaneously detection of dopamine and ascorbic acid

    International Nuclear Information System (INIS)

    A composite film based on K8P2W16V2O62·18H2O decorated by Au–Pd nanoparticles was prepared by the layer-by-layer self-assembly method. This composite film exhibits enhanced electrocatalytic performance, repeatability and long-term stability for the simultaneous determination of dopamine and ascorbic acid at biological pH (pH 7.0). The proposed electrochemical sensing film for simultaneous detecting dopamine and ascorbic acid shows rather low detection limit of 8.3 × 10?7 and 4.3 × 10?7 M and a linear response range from 2.1 × 10?6 to 2.06 × 10?3 M and 1.2 × 10?6 to 1.61 × 10?3 M, as well as no interference from the common interfering species at an applied potential. -- Abstract: A novel composite film based on Dawson-type phosphovanadotungstate K8P2W16V2O62·18H2O (P2W16V2) decorated by Au–Pd alloy nanoparticles (Au–Pd) was fabricated on quartz, silicon and ITO using the layer-by-layer self-assembly method. The composite film was characterized by UV–vis spectroscopy, X-ray photoelectron spectra, atomic force microscopy, Scanning electronic microscope, cyclic voltammetry and differential pulse voltammetry. The composite film can be employed for sensitive and simultaneous determination of dopamine and ascorbic acid at biological pH (pH 7.0). Linear analytical curves were obtained in the ranges from 2.1 × 10?6 to 2.06 × 10?3 M and 1.2 × 10?6 to 1.61 × 10?3 M for dopamine and ascorbic acid by DPV methods, respectively. The low detection limit for dopamine and ascorbic acid were 8.3 × 10?7 and 4.3 × 10?7 M, as well as no interference was observed from the common interfering species such as glucose, uric acid, L-cysteine, CH3OH, CH3CH2OH and H2O2. The composite film was used for dopamine and ascorbic acid determinations in real samples with satisfactory results. With high sensitivity and selectivity, the proposed electrochemical sensor would provide a simple method for simultaneous determination of dopamine and ascorbic acid in practical applications

  9. Immunohistochemical localization of sodium-dependent L-ascorbic acid transporter 1 protein in rat kidney.

    Science.gov (United States)

    Lee, Ju Hyun; Oh, Chang Seok; Mun, Ga Hee; Kim, Jae Hyup; Chung, Yoon Hee; Hwang, Young Il; Shin, Dong Hoon; Lee, Wang Jae

    2006-10-01

    Recently, two L-ascorbic acid transporters were identified; sodium-dependent vitamin C transporter (SVCT) 1 and SVCT2. The previous study suggested that SVCT protein might be present on the apical membrane in the straight segment (S3) of proximal tubule. In the present study, SVCT1 immunoreactivity (IR) was observed in the brush border of proximal straight tubules in the medullary ray of renal cortex and the outer stripe of outer medulla, while SVCT2 IR was not localized in any region of the kidney. Since the mechanism of VC reabsorption in the kidney has not been fully elucidated up to the present time, it is meaningful to demonstrate the exact cellular distribution of SVCT protein in the kidney. PMID:16673096

  10. Polyoxometalate-Graphene Nanocomposite Modified Electrode for Electrocatalytic Detection of Ascorbic Acid

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Weiying; Du, Dan; Gunaratne, Kalupathirannehelage Don D.; Colby, Robert J.; Lin, Yuehe; Laskin, Julia

    2014-01-15

    Phosphomolybdate functionalized graphene nanocomposite (PMo12-GS) has been successfully formed on a glassy carbon electrode (GCE) for the detection of ascorbic acid (AA). The obtained PMo12-GS modified GCE, was characterized by cyclic voltammetry, electrochemical impedance spectroscopy, scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy and compared with GCE, GS modified GCE, and PMo12 modified GCE. It shows an increased current and a decrease in over-potential of ~210 mV. The amperometric signals are linearly proportional to the AA concentration in a wide concentration range from 1×10−6 M to 8×10−3 M, with a detection limit of 0.5×10−6 M. The PMo12-GS modified electrode was employed for the determination of the AA level in vitamin C tablets, with recoveries between 96.3 and 100.8 %.

  11. Ascorbic acid-functionalized Ag NPs as a probe for colorimetric sensing of glutathione

    Science.gov (United States)

    D'souza, Stephanie L.; Pati, Ranjan; Kailasa, Suresh Kumar

    2015-08-01

    In this work, we report the use of ascorbic acid-capped silver nanoparticles (AA-Ag NPs) as a probe for selective colorimetric detection of glutathione (GSH) in aqueous solution. This detection system was based on the GSH-induced aggregation of AA-Ag NPs, resulting in drastic changes in the absorption spectra and color of the AA-Ag NPs system. The GSH-induced AA-Ag NPs aggregation was confirmed by UV-visible spectrometry, dynamic light scattering (DLS) and transmission electron microscopic (TEM) techniques. Under optimal conditions, this method exhibited good linearity over the concentration ranges from 5.0 to 50 µM, with the limit of detection 2.4 × 10-7 M. This method was successfully applied to detect GSH in the presence of other biomolecules, which confirms that this probe can be used for the detection of GSH in real samples.

  12. Cadmium sulfide photocatalysed reduction of malachite green by ascorbic acid and EDTA as reductants

    Scientific Electronic Library Online (English)

    Shilpa, Kothari; Anil, Kumar; Ritu, Vyas; Rakshit, Ameta; Pinki B., Punjabi.

    Full Text Available Foi efetuada a fotoredução do verde de malaquita na presença de CdS como fotocatalizador e ácido ascorbico/EDTA como redutores. Foram estudados os efeitos de diferentes parâmetros como pH, concentração de verde de malaquita, redutores, quantidade de semicondutor e intensidade de luz, na velocidade d [...] a reação fotocatalítica. Levando em conta os dados obtidos propomos um de mecanismo.para a fotoredução do verde de malaquita. Abstract in english The photoreduction of malachite green in presence of CdS as photocatalyst and ascorbic acid/EDTA as reductants has been carried out. The effect of different parameters like pH, concentration of malachite green, reductants, amount of semiconductor and light intensity on the rate of photocatalytic rea [...] ction has been studied. On the basis of observed data, a tentative mechanism for the photoreduction of malachite green has been proposed.

  13. SPECTROPHOTOMETRIC DETERMINATION OF RITONAVIR BY CONDENSATION METHOD USING NINHYDRIN AND ASCORBIC ACID

    Directory of Open Access Journals (Sweden)

    M.L.N.Acharyulu

    2013-02-01

    Full Text Available A simple and sensitive extractive visible spectrophotometric method for the assay ofRitonavir in pure and pharmaceutical Formulations based on the reaction between peptidegroup in RIT and Ninhydrin in the presence of ascorbic acid affords a blue violet coloured product (λmax 560nm. Regression analysis of Beer-Lambert plots showed good correlation in the concentration ranges (20-60 μg/ml. The percent recoveries are obtained as 99.64 ±0.47 to 100.40 ±0.45 by proposed method and 99.51 ±0.25 to 99.92 ±0.20 by reference method for the formulations respectively. The method can be applied successfully for the estimation of the Ritonavir in the presence of other ingredients that are usually present in formulations. The method offers the advantage of rapidity, simplicity and sensitivity and low cost without the need for expensive instrumentation and reagents.

  14. Silver nanoparticles prepared in presence of ascorbic acid and gelatin, and their electrocatalytic application

    Indian Academy of Sciences (India)

    Fereshteh Chekin; Somayeh Ghasemi

    2014-10-01

    In this paper, we reported a simple and low-cost procedure to synthesize silver nanoparticles (AgNPs) by using ascorbic acid as reducing agent and gelatin as stabilizer. The synthesized AgNPs were characterized by various means such as transmission electron microscope (TEM), powder X-ray diffraction (XRD) and energy-dispersive X-ray (EDX). TEM observations and XRD analysis demonstrated that the size of AgNPs is about 20 nm. Silver nanoparticles modified with carbon-paste electrode (AgNPs–CPE) displayed excellent electrochemical catalytic activities towards hydrogen peroxide (H2O2). The reduction overpotential of H2O2 was decreased significantly compared with those obtained at the bare CPE. The sensor responded linearly to hydrogen peroxide (H2O2) in the concentration of 10–350 M, with detection limit of 5.6 M at 3 using amperometry. The studied sensor exhibited good reproducibility and long-term stability.

  15. Effects of Ascorbic Acid on Egg Production and Egg Shell Quality in Laying Hens Drinking Saline Water

    Directory of Open Access Journals (Sweden)

    J. Mirabdollbaghi

    2006-01-01

    Full Text Available An experiment was conducted to study the effects of different water source, saline water (Tap water +2 g L-1 Na and tape water with a diet that supplemented by three level of Ascorbic Acid (0, 1.5 and 3 g kg-1 of diet on laying hen`s performance and egg shell quality. This trail was carried out on 108 commercial laying hens (Hy-Line 32 weeks old for 12 weeks. All of the data were subjected to Two- way analysis of variance test. The result showed that egg production (%, egg weight (g, egg mass (g/h/day, feed conversion ratio, feed consumptions didn`t effected by saline water but using saline water increased the percentage of eggs with damaged shells (p<0.01. Also the effect of different level of Ascorbic acid on egg production (%, egg weight (g, egg mass (g/h/day, feed conversion ratio were not significant, but feed consumption reduced by using ascorbic acid (p<0.05. Egg shell thickness (mm, egg shell weight (%, egg shell weight (mg/cm2, egg specific gravity, egg shell calcium (% and egg shell phosphorous (% didn`t affected by saline water and different level of Ascorbic acid.

  16. Effects of ascorbic acid on interactions between ciprofloxacin and ferrous sulphate, sodium ferrous citrate or ferric pyrophosphate, in mice.

    Science.gov (United States)

    Motoya, T; Miyashita, M; Kawachi, A; Yamada, K

    2000-04-01

    The absorption of ciprofloxacin has been reported to be impaired by concomitant administration of ferrous sulphate. The effects of sodium ferrous citrate and ferric pyrophosphate, which have been used as extensively as ferrous sulphate, on the absorption of ciprofloxacin were compared with that of ferrous sulphate. The effects of ascorbic acid on the interactions between ciprofloxacin and each iron compound were studied in mice. Mice were treated orally with ciprofloxacin (50 mg kg(-1)) alone, the iron compound (ferrous sulphate, sodium ferrous citrate or ferric pyrophosphate; 50 mg elemental iron kg(-1)) alone, ciprofloxacin with each iron compound or ciprofloxacin in combination with each iron compound and ascorbic acid (250 mg kg(-1)). The maximum serum concentration of ciprofloxacin was significantly (P ferric pyrophosphate was administered along with ciprofloxacin. The addition of ascorbic acid did not affect the inhibitory effects of each iron compound on the absorption of ciprofloxacin. Ciprofloxacin did not affect the variation of serum iron levels after administration of each iron compound. The addition of ascorbic acid significantly (P ferric pyrophosphate, although it did not affect the levels after ferrous sulphate administration. The results suggest that sodium ferrous citrate and ferric pyrophosphate should not be administered with ciprofloxacin (as for ferrous sulphate) and that sodium ferrous citrate is converted to the ferric form more easily than ferrous sulphate. This difference in convertibility might contribute to a clinical difference between sodium ferrous citrate and ferrous sulphate. PMID:10813549

  17. Ascorbic Acid-Initiated Tandem Radical Cyclization of N-Arylacrylamides to Give 3,3-Disubstituted Oxindoles

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    Sheng Liu

    2015-08-01

    Full Text Available An ascorbic acid-promoted and metal-free tandem room temperature cyclization of N-arylacrylamides with 4-nitrobenzenediazonium generated in situ was developed. This reaction proceeds smoothly through a radical mechanism and provides an environmentally friendly alternative approach to biologically active 3-alkyl-3-benzyloxindoles, avoiding the use of excess oxidants and light irradiation.

  18. Effect of ascorbic acid on long-term cold exposure induced changes in thyroid activity in sprague dawley rats

    International Nuclear Information System (INIS)

    Objective: To determine the effect of ascorbic acid supplementation on long-term cold exposure induced changes in thyroid activity in Sprague-Dawley rats. Study Design: Experimental study. Place and Duration of Study: Physiology Department of Islamic International Medical College, Rawalpindi, National Institute of Health, Islamabad and Railway Hospital, Rawalpindi, from January to December 2009. Methodology: Ninety Sprague-Dawley rats were randomly divided into three groups of control, cold exposed and cold exposed along with ascorbic acid supplementation. After one month, their thyroid levels were analyzed by using chemiluminescent immunometric Assay on Siemens Immulite 2000 Analyzer. Results: After 4 weeks of cold exposure to experimental animals, the thyroid activity was raised significantly in the cold exposed group as compared to the control group (p-value for T3 difference = 0.004, T4 difference = 0.002 and TSH difference < 0.001). Supplementation with ascorbic acid in the third group normalized the thyroid hormone activity with p-value for difference in levels of T3 being 0.6661, T4 = 0.027 and TSH = 0.0028. Conclusion: Ascorbic acid prevented the cold induced changes in thyroid hormone levels in rodents. (author)

  19. ISOLATION AND SEQUENCING OF A GENOMIC DNA ENCODING FOR ASCORBATE OXIDASE, A KEY ENZYME INVOLVED IN THE BIODEGRADATION OF ASCORBIC ACID IN MELON

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    Evangelos ALATSATIANOS

    2002-03-01

    Full Text Available A melon genomic library was used to isolate and characterize a clone of genomic DNA coding for ascorbate oxidase (AO which is considered a key enzyme in the biodegradation of ascorbic acid (AA. The screening of genomic library was performed by using two probes: AO-PCR product and ?E/CMAO3. Seven clones of recombinant phage, with positive signal, were isolated. The extracted DNA was digested with EcoRI, Sal I and Bam HI and the combinations among these restriction enzymes. Four clones of AO gene were isolated: AO1; AO2; AO3 and AO4. Since only clone AO4 had not been characterized so far, the sequencing of this clone was performed. The isolated sequence of DNA has a length of 3072 bp being bordered at both ends by EcoRI enzymes. The comparison between genomic DNA for AO4 in melon and DNA for AO in cucumber revealed a high similarity (94.45%.

  20. Antitumoral activity of L-ascorbic acid-poly-D,L-(lactide-co-glycolide nanoparticles containing violacein

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    Dorival Martins

    2010-01-01

    Full Text Available Dorival Martins1, Lucas Frungillo2, Maristela C Anazzetti2, Patrícia S Melo3, Nelson Durán11Institute of Chemistry, Biological Chemistry Laboratory, Universidade Estadual de Campinas-UNICAMP, C.P. 6154, CE P 13083-970, Campinas, SP, Brazil; 2Institute of Biology, Cell Cultures and Biopharmaceutical Laboratory, Universidade Estadual de Campinas, UNICAMP, Campinas, SP, Brazil; 3Campinas Integrated Metropolitan Faculties-METROCAMP, Campinas, SP, BrazilAbstract: It has been demonstrated that tumoral cells have a higher uptake of ascorbic acid compared to normal cells. This differential characteristic can be used as a way to improve the specificity of antitumoral compounds if combined with polymeric drug delivery systems. The aim of this study was to prepare, characterize and evaluate the antitumoral activity of poly-D,L-(lactide-co-glycolide 50:50 loading the antitumoral compound violacein and capped with L-ascorbic acid. Nanoparticles were prepared using the nanoprecipitation method and morphologically characterized by scanning electron microscopy (SEM. The average diameter and Zeta potential were determined by photon correlation spectroscopy method (PCS, and assays were carried out to determine the content of ascorbic acid and in vitro drug release kinetics. The antitumoral activity of this system was also evaluated against HL-60 cells by tetrazolium reduction assay. Nanoparticles with size distribution between 300–400 nm and strong negative outer surface (-40 mV were obtained by this method. Analysis of ascorbic acid content showed that this compound was mainly localized on the external surface of nanoparticles. Violacein loading efficiency was determined as 32% ± 1% and this drug was gradually released from nanoparticles at different rates depending on the composition of the release media. In addition, this system was observed to be 2 × more efficient as an antitumoral compared with free violacein.Keywords: violacein, ascorbic acid, nanoparticles, PLGA

  1. Therapeutic Potential effects of pyridoxine and /or ascorbic acid on Microalbuminuria in diabetes mellitus patient's: a randomized controlled clinical study

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    Hayder M. Al-Kuraishy

    2013-06-01

    Full Text Available Objectives: This study aimed to evaluate the therapeutic potential effects of ascorbic acid or and pyridoxine on diabetic renal microalbumiuria. Methods: This was a cross-sectional study on patients with diabetes mellitus at Al-Yarmouk teaching hospital from January to December 2012, Iraq-Baghdad. Twenty one patients with diabetes mellitus (D.M, 8 IDDM and 13 IDDM were selected from, the duration of disease were ranged from 2-12 years for both type (10 females and 11males and all enrolled patients ages were ranged from 28-65years. The concentration of total protein in urine was calculated by a biuret colorimetric assay and the urine creatinine level was measured by a modified Jaffe test. Statistical analysis: results are expressed as mean ± SD, for comparisons of two groups, Student’s t-test was used and statistical significance was accepted at p values < 0.05. Results: pyridoxine produced significant reduction in urinary albumin:creatinine ratio in patients with Type ?? D.M with the current therapy p?0.05 except with glimepiride p ?0.05 while the Ascorbic acid showed significant effect on albumin:creatinine in patients with Type ?? D.M after six week of treatment p ?0.05except on patient that treated with glibenclamide or glimepiride p?0.05. Combined effects of ascorbic acid 500 mg/day and pyridoxine 40mg/day on urinary albumin:creatinine produced significant reduction in albumin: creatinine ratio in both Type ? D.M and Type ?? D.M p ?0.05. Conclusions: Dual synergistic effects of ascorbic acid and pyridoxine produced more beneficial effects than either ascorbic acid or pyridoxine in amelioration of diabetic microalbuminuric nephropathy.

  2. Modification of Death rate and Disturbances induced in the Levels of serum total Lipids and free fatty acids of irradiated rats by ascorbic acid and serotonin

    International Nuclear Information System (INIS)

    Intraperitoneal injection of normal rats with ascorbic acid (10 mg/100 g body weight ) or serotonin (2 mg/100 g body weight) had no harmful effect on the life span. Moreover, the levels of serum total lipids and free fatty acids did not show any significant changes at 3, 7, 10 and 14 days after injection. Administration of ascorbic acid or serotonin to rats at the pre mentioned doses, 15 minutes, before gamma irradiation at 7.5 Gy (single dose ) improved the survival time of rats and the hyperlipemic state recorded after radiation exposure

  3. Hierarchical nanoporous platinum-copper alloy for simultaneous electrochemical determination of ascorbic acid, dopamine, and uric acid

    International Nuclear Information System (INIS)

    A hierarchical nanoporous PtCu alloy was fabricated by two-step dealloying of a PtCuAl precursor alloy followed by annealing. The new alloy possesses interconnected hierarchical network architecture with bimodal distributions of ligaments and pores. It exhibits high electrochemical activity towards the oxidation of ascorbic acid (AA), dopamine (DA), and uric acid (UA) at working potentials of 0.32, 0.47 and 0.61 V (vs. a mercury sulfate reference electrode), respectively. The new alloy was placed on a glassy carbon electrode and then displayed a wide linear response to AA, DA, and UA in the concentration ranges from 25 to 800 ?M, 4 to 20 ?M, and 10 to 70 ?M, respectively. The lower detection limits are 17.5 ?M, 2.8 µM and 5.7 ?M at an S/N ratio of 3. (author)

  4. Determination of ascorbic acid, dopamine, and uric acid by a novel electrochemical sensor based on pristine graphene

    International Nuclear Information System (INIS)

    In this article, a novel electrochemical sensor based on pristine graphene (PG) is successfully constructed to detect ascorbic acid (AA), dopamine (DA), and uric acid (UA). The PG is obtained by liquid-phase exfoliation of graphite and characterized by transmission electron microscopy and X-ray photoelectron spectroscopy. The sensor based on PG prepared by this method to realize simultaneous determination of AA, DA, and UA is firstly reported. The linear detection ranges for AA, DA, and UA are 9.00–2314 μM, 5.00–710 μM, and 6.00–1330 μM, respectively, with detection limits of 6.45, 2.00, and 4.82 μM. This PG based sensor exhibits excellent performance for detection of AA, DA, and UA, which is much better than those electrochemical sensors based on chemical converted graphene

  5. Ascorbic acid is superior to silymarin in the recovery of ethanol-induced inflammatory reactions in hepatocytes of guinea pigs.

    Science.gov (United States)

    Abhilash, P A; Harikrishnan, R; Indira, M

    2013-12-01

    Both oxidative stress and inflammatory reactions play a major role in alcoholic liver fibrosis. We evaluated the efficacy of ascorbic acid (AA) and silymarin in the regression of alcohol-induced inflammation in hepatocytes of guinea pigs (Cavia porcellus). Animals were administered with ethanol at a daily dose of 4 g/kg body weight (b.wt) for 90 days. On the ninety-first day, ethanol administration was stopped and animals were divided into alcohol abstention group and silymarin- (25 mg/100 g b.wt) and AA- (25 mg/100 g b.wt) supplemented groups and maintained for 30 days. There was a significant increase in the activities of alanine aminotransferase, aspartate aminotransferase, and ?-glutamyl transpeptidase in the serum of the ethanol group. The intracellular reactive oxygen species (ROS) and expressions of cytochrome P4502E1 and nuclear factor ?B1, tumor necrosis factor-?, and transforming growth factor-?(1) in hepatocytes were significantly increased in ethanol group. The fibrotic markers ?-smooth muscle actin and ?(1)(I) collagen and activity of cytotoxicity marker caspase-3 were significantly increased and AA content was significantly reduced in hepatocytes of alcohol-treated guinea pigs. But the AA and silymarin supplementation significantly reduced these changes in comparison with alcohol abstention group. AA could induce greater reduction of inflammatory and fibrotic markers in hepatocytes than silymarin. This indicates that AA is superior to silymarin in inhibiting intracellular ROS generation and thereby reducing the ethanol-induced inflammation in hepatocytes. PMID:23653339

  6. Protective role of ascorbic acid isolated from Cissus quadrangularis on NSAID induced toxicity through immunomodulating response and growth factors expression.

    Science.gov (United States)

    Jainu, Mallika; Mohan, Kunju Vijai

    2008-12-20

    The present study investigate the effect of ascorbic acid, the major bioactive component isolated from Cissus quadrangularis extract (CAA) on inflammatory cytokines and growth factors in non-steroidal anti-inflammatory drug (NSAID) induced gastric ulcer. Analysis of serum cytokine profile using enzymelinked immunosorbent assay (ELISA) showed a drastic increase in interleukin (IL)-1beta, IL-6, tumour necrosis factor-alpha (TNF)-alpha, interferon-gamma (IFN-gamma) and decrease in IL-10, Il-4 and prostaglandin E2 (PGE2) levels in NSAID (aspirin) treated rats. The reduction of growth factors such as transforming growth factor-alpha (TGF)-alpha and vascular endothelial cell growth factor (VEGF) by aspirin was determined by immunohistochemistry method. Administration of CAA produced significant protection against aspirin induced gastric toxicity by showing significant increase in PGE2, TGF-alpha, VEGF expression and accompanied by a significant inhibition of nitric oxide and regulating the levels of cytokines in rats. These findings suggest that CAA prevents gastric ulcer formation due to its immunomodulatory effect, antioxidant activity along with the ability to modulate PG synthesis and up-regulation of the growth factors. PMID:18773975

  7. Study on the Ascorbic Acid Content of rose Hip fruit Depending on Stationary Conditions

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    Sorina Ropciuc

    2011-10-01

    Full Text Available The dog rose area includes southern and central Europe, reaching southern Scandinavia; it is also found in Asia Minor, Central Asia and North Africa. In our country, Rosa canina is the most widespread of the many species of Rosa, common in all areas. The components of the station, known also as the „stationary factors” affect differently the plant life and their chemical composition. Cynosbati fructus is the false fruit of Rosa canina L. (Rosaceae, known in Romanian as rose hip. The rose hip contain as active ingredients 500-1000 % vitamin C, 600-10000 mg% carotenoids, pectin, dextrin, vitamins B2, E, PP, flavone, sugars, organic acids, tannins, volatile oil, vanillin, triterpenoid saponosides, beta-sitosterol, fat (lecithin, glycerides of fatty acids in seeds, minerals (potassium, calcium, magnesium, iron. Vitamin C (ascorbic acid plays an important role in human body. The greatest amount is found in plants which reached maturity. It is concentrated in the rose hip flesh. Solutions easily destroyit in the presence of UV, of copper, silver, iron and oxidative enzymes traces. Vitamin C participates actively in all processes of oxidoreductions of the living cell. Its lack in food causes the disease called scurvy which manifests itself by inflammated and bleeding gums, tooth loss. Rose hip fruits are known as medicines since prehistoric times.

  8. Biomarkers of lead exposure in petrol station attendants and auto-mechanics in Abeokuta, Nigeria: effect of 2-week ascorbic acid supplementation.

    Science.gov (United States)

    Onunkwor, B; Dosumu, O; Odukoya, O O; Arowolo, T; Ademuyiwa, O

    2004-07-01

    In order to study the ameliorative effects of ascorbic acid in chronic lead poisoning, petrol station attendants and auto-mechanics in Abeokuta, Nigeria, who have been shown to be occupationally exposed to lead and university students (serving as control), were supplemented daily with 500mg ascorbic acid for 2 weeks. Blood and urine samples were collected from the subjects before and after ascorbic acid regimen and analysed for lead and biochemical effects associated with lead toxicity. The 2-week ascorbic acid supplementation resulted in a significant (P < 0.05) reduction in blood lead in the occupationally exposed subjects. The reduction in blood lead amounted to 57% in male petrol station attendants, 50% in female petrol station attendants and 44% in the auto-mechanics. Urinary excretion of lead increased remarkably in the occupationally exposed subjects (P < 0.05). The biochemical effects associated with the toxic effects of lead also responded positively to the ascorbic acid regimen. Plasma and urine aminolevulinic acid (ALA) were reduced significantly (P < 0.05) by as much as 55% and 57% respectively. Plasma calcium also increased significantly (P < 0.05) in the subjects. Decreased levels of reduced glutathione (GSH) and hemoglobin observed in the occupationally exposed subjects were reversed by ascorbic acid. Glutathione-S-transferase (GST) and catalase (CAT) activities were not affected. Our findings indicate that ascorbic acid may be useful as an economical and convenient prophylactic agent for lead poisoning. PMID:21782728

  9. Sodium orthovanadate associated with pharmacological doses of ascorbate causes an increased generation of ROS in tumor cells that inhibits proliferation and triggers apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Günther, T-hat nia Mara Fischer; Kviecinski, Maicon Roberto; Baron, Carla Cristine; Felipe, Karina Bettega; Farias, Mirelle Sifroni; Ourique da Silva, Fabiana; Bücker, Nádia Cristina Falcão [Departamento de Bioquímica, Universidade Federal de Santa Catarina, Florianópolis (Brazil); Pich, Claus Tröger [Campus de Araranguá, Universidade Federal de Santa Catarina, Araranguá (Brazil); Ferreira, Eduardo Antonio [Universidade de Brasília, Faculdade de Ceilândia, DF (Brazil); Filho, Danilo Wilhelm [Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis (Brazil); Verrax, Julien; Calderon, Pedro Buc [Toxicology and Cancer Biology Research Group, Louvain Drug Research Institute, Université Catholique de Louvain, Brussels (Belgium); Pedrosa, Rozangela Curi, E-mail: rozangelapedrosa@gmail.com [Departamento de Bioquímica, Universidade Federal de Santa Catarina, Florianópolis (Brazil)

    2013-01-18

    Graphical abstract: -- Abstract: Pharmacological doses of ascorbate were evaluated for its ability to potentiate the toxicity of sodium orthovanadate (Na{sub 3}VO{sub 4}) in tumor cells. Cytotoxicity, inhibition of cell proliferation, generation of ROS and DNA fragmentation were assessed in T24 cells. Na{sub 3}VO{sub 4} was cytotoxic against T24 cells (EC{sub 50} = 5.8 ?M at 24 h), but in the presence of ascorbate (100 ?M) the EC{sub 50} fell to 3.3 ?M. Na{sub 3}VO{sub 4} plus ascorbate caused a strong inhibition of cell proliferation (up to 20%) and increased the generation of ROS (4-fold). Na{sub 3}VO{sub 4} did not directly cleave plasmid DNA, at this aspect no synergism was found occurring between Na{sub 3}VO{sub 4} and ascorbate once the resulting action of the combination was no greater than that of both substances administered separately. Cells from Ehrlich ascites carcinoma-bearing mice were used to determine the activity of antioxidant enzymes, the extent of the oxidative damage and the type of cell death. Na{sub 3}VO{sub 4} alone, or combined with ascorbate, increased catalase activity, but only Na{sub 3}VO{sub 4} plus ascorbate increased superoxide dismutase activity (up to 4-fold). Oxidative damage on proteins and lipids was higher due to the treatment done with Na{sub 3}VO{sub 4} plus ascorbate (2–3-fold). Ascorbate potentiated apoptosis in tumor cells from mice treated with Na{sub 3}VO{sub 4}. The results indicate that pharmacological doses of ascorbate enhance the generation of ROS induced by Na{sub 3}VO{sub 4} in tumor cells causing inhibition of proliferation and apoptosis. Apoptosis induced by orthovanadate and ascorbate is closer related to inhibition on Bcl-xL and activation of Bax. Our data apparently rule out a mechanism of cell demise p53-dependent or related to Cdk2 impairment.

  10. [Catalytic spectrophotometric determination of trace amounts of copper with the system of ascorbic acid and ammonium molybdate].

    Science.gov (United States)

    Ding, S

    2000-04-01

    Ammonium molybdate was reduced to molybdenum blue by ascorbic acid in the medium of phosphorous acid in the presence of copper catalyst. A new method for catalytic spectrophotometric determination of trace copper has been developed. The linear range was 0-0.024 microgram.25 mL-1. The limit of detection was 1.54 x 10(-11) g.mL-1. The method has been used to determine trace copper in human hair with satisfactory results. PMID:12953501

  11. Thermal-driven attachment of gold nanoparticles prepared with ascorbic acid onto indium tin oxide surfaces

    International Nuclear Information System (INIS)

    Thermal-driven attachment of gold nanoparticles (AuNPs), of which size was less than 50 nm, onto the surfaces of indium tin oxide (ITO) is reported as a new phenomenon. This was permitted by preparing AuNPs via the reduction of hydrogen tetrachloroaurate (HAuCl4) with ascorbic acid (AA). While the AuNPs prepared via the AA reduction sparsely attached on the surface of ITO even at room temperature, a heat-up treatment at ca. 75 °C caused denser attachment of AuNPs on ITO surfaces. The attached density and the homogeneity after the thermal treatment were better than those of AuNP/ITO prepared using 3-aminopropyl-trimethoxysilane linker molecules. The denser attachment was observed similarly both by the immersion of ITO samples after the preparations of AuNPs by AA and by the in situ preparation of AuNPs with AA together with ITO samples. Thus, it is considered that the thermal-driven attachment of AuNPs would occur after the formation of AuNPs in the aqueous solutions, not via the growth of AuNPs on ITO surfaces. The preparation of AuNPs with AA would be a key for the thermal-driven attachment because the same attachments were not observed for AuNPs prepared with citrate ions or commercially available tannic acid-capped AuNPs.

  12. Mechanisms of the influence of UV irradiation on collagen and collagen-ascorbic acid solutions

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    A. Sionkowska

    2006-09-01

    Full Text Available The study of the influence of UV irradiation on collagen solutions has shown the destabilization of the collagen molecule by calorimetric method. It is reflected both in changes of thermodynamic parameters of transition (Tm, ΔH, Cp=f(t and in the appearance of a low temperature peak, that is practically irreversible against rescanning. All these indicate that the important defects in the molecule occur. The ESR measurements have shown that the above-mentioned thermal changes are connected with the occurrence of free radicals in solution under UV irradiation. They interact with proline (Pro residues of the protein with the appearance of secondary free radicals, with following migration to glycine (Gly residues. The emergence of the free radicals at the Pro and then at the Gly residues may cause the dramatic structural defect resulting from the UV irradiation, which significantly alters the network of hydrogen bonds in the triple helix of the collagen molecule. All this is connected with destabilization of the collagen molecule, because the defects in amino acid residues probably lead to cleavage of covalent bonds near the damaged sites maintaining the triple helical structure. The presence of ascorbic acid in collagen solution protects the collagen molecule from occurring of secondary free radicals.

  13. Ascorbic acid and citric flavonoids for broilers under heat stress: effects on performance and meat quality

    Scientific Electronic Library Online (English)

    JEM, Peña; SL, Vieira; J, López; RN, Reis; R, Barros; FVF, Furtado; PX, Silva.

    2008-06-01

    Full Text Available The aim of this study was to evaluate the effects of increasing doses of ascorbic acid (AA) and citric flavonoids (quercetin and rutin) on the performance and meat quality characteristics of broilers submitted to cyclic heat stress. Four-hundred one-day-old female Ross 308 were housed in 40 battery [...] cages a in temperature controlled room. Treatments consisted of 0, 250, 500, and 1000 g/ton on of AA + citric flavonoids. Birds were fed ad libitum until 32 day of age. Beginning on day 14 post-hatch until the end of the experiment, in order to simulate cyclic heat stress, the temperature inside the room was increased to 32°C for 5 hours, and decreased until reaching the comfort temperature corresponding to the age of the animals. Birds were slaughtered at 33 days of age, and carcass and commercial cuts yields were determined. Thighs and boneless breast samples were collected and frozen for subsequent analyses of pH, cooking loss, shear force, color, and Thiobarbituric Acid Reactive Substances (TBARS). Significant differences (p

  14. Methylene blue immobilized on cellulose acetate with titanium dioxide: an application as sensor for ascorbic acid

    Scientific Electronic Library Online (English)

    Andrea A., Hoffmann; Silvio L. P., Dias; Jordana R., Rodrigues; Flavio A., Pavan; Edilson V., Benvenutti; Eder C., Lima.

    Full Text Available Neste trabalho, o corante azul de metileno foi imobilizado na superfície do acetato de celulose modificado com dióxido de titânio produzindo um material híbrido sólido denominado de CA-TiO2MB. O experimento produziu uma quantidade de 1,8 mmol g-1 de TiO2 incorporado no acetato de celulose e uma quan [...] tidade de 0,170 ± 0,005 mmol g-1 de azul de metileno adsorvido na superfície do CA-TiO2. Um eletrodo de pasta de carbono desse material foi usado para estudar a oxidação eletrocatalítica do ácido ascórbico pelas técnicas de voltametria cíclica e cronoamperometria. O pH da solução não afetou o potencial de pico de anódico nem a corrente de pico anódico ao variar de 3,0 a 7,0. A oxidação do analito ocorreu em 75 mV versus ECS em solução de KCl 1,0 mol L-1 e pH 7,0. A intensidade da corrente de pico anódico variou com a concentração de ácido ascórbico na faixa de 5,0 × 10-4 mol L-1 to 4,5 × 10-3 mol L-1, sendo observada uma correlação linear com um limite de detecção de 15 µmol L-1, limite de quantificação de 50 µmol L-1 e uma sensibilidade de 7,1 µA L mol-1. A resposta do eletrodo foi muito rápida, com um tempo decorrido de 1,0 s, mostrando potencial para ser utilizado como um sensor eletroquímico para a determinação de ácido ascórbico em produtos comerciais. Abstract in english In this work, methylene blue dye was immobilized on the surface of cellulose acetate modified with titanium dioxide, producing a solid hybrid material designated as CA-TiO2MB. The experiment yielded an amount of 1.8 mmol g-1 of TiO2 incorporated in the cellulose acetate and an amount of 0.170 ± 0.00 [...] 5 mmol g-1 of methylene blue adsorbed onto CA-TiO2 surface. A carbon paste electrode of this material was used to study the electrocatalytic oxidation of ascorbic acid by cyclic voltammetric and chronoamperometric techniques. The pH of the solution had no effect on the anodic peak potential and anodic peak current when ranging from 3.0 to 7.0. The oxidation of the analyte occurred at 75 mV versus SCE in 1.0 mol L-1 KCl solution and pH 7.0. The intensity of the anodic peak current varied with the concentration of ascorbic acid from 5.0 × 10-4 mol L-1 to 4.5 × 10-3 mol L-1 and a linear correlation was observed, with a detection limit of 15 µmol L-1, quantification limit of 50 µmol L-1 and a sensitivity of 7.1 µA L mol-1. The electrode response was very fast, with an elapsed time of about 1.0 s, showing the potentiality to be utilized as an electrochemical sensor for determination of ascorbic acid in commercial samples.

  15. Ascorbic acid/saline eluant increases 188Re yields after ''wet'' storage of 188W/188Re generators

    International Nuclear Information System (INIS)

    We have evaluated several factors in an attempt to minimize the reduced yields observed after ''wet'' storage of 188W/188Re generators, which include the dispersion of 188W-tungstic acid in the alumina column bed by pre-mixing with silica gel, incorporation of cupric ion as an antioxidant in the adsorbent, and elution of the alumina columns with saline containing ascorbic acid. The results demonstrate that dispersion of the 188W-tungstic acid in a silica-alumina bed and the use of cupric ion do not significantly increase 188Re yields after weekend ''wet'' storage. In contrast, addition of ascorbic acid at concentrations as low as 0.01% in the saline eluant was found to be an effective method of maintaining good 188Re yields after ''wet'' weekend storage, resulting in Monday elution yields greater than 70%. Use of low concentrations of ascorbic acid is thus an effective alternative to drying the generator columns before storage. (author)

  16. Ascorbic acid, garlic extract and taurine alleviate cadmium-induced oxidative stress in freshwater catfish (Clarias batrachus)

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Puneet, E-mail: puneetbiochem@gmail.com [Aquatic Biotechnology and Fish Pathology Laboratory, Department of Animal Science, M.J.P. Rohilkhand University, Bareilly-243 006 (India); Prasad, Y. [Aquatic Biotechnology and Fish Pathology Laboratory, Department of Animal Science, M.J.P. Rohilkhand University, Bareilly-243 006 (India); Patra, A.K. [West Bengal University of Animal and Fishery Sciences, Kolkata-700037 (India); Ranjan, R.; Swarup, D.; Patra, R.C. [Division of Medicine, Indian Veterinary Research Institute, Izatnagar-243122 (India); Pal, Satya [Env. Eng. Lab., Deptt. of Civil Engineering, I.I.T., Roorkee-247667 (India)

    2009-09-01

    An experiment was conducted to investigate bioaccumulation potential of cadmium (Cd) and changes in oxidative stress indices in liver and kidney tissues from Cd-exposed catfish (Clarias batrachus) with or without simultaneous treatment of water with ascorbic acid, garlic extract or taurine. C. batrachus (n = 324) with average length of 20 {+-} 4 cm and weight of 86 {+-} 5 g were used for the present investigation. Fishes were divided into nine groups (I to IX) each comprising 36 fishes. The fishes of groups II, III, IV and V were challenged with 5 ppm of cadmium chloride monohydrate (CdCl{sub 2}.H{sub 2}O), whereas groups VI, VII, VIII and IX were exposed to 10 ppm CdCl{sub 2}.H{sub 2}O solution for a period of 45 days. Group I was kept as negative control and the fishes of this group were maintained in water containing no added Cadmium. Group II and VI were maintained as Cd exposed non treated control to serve as positive controls. Fishes of III and VII, IV and VIII, V and IX received ascorbic acid (5 ppm), extract of dried garlic (5 ppm) or taurine (5 ppm), respectively during the entire experiment period. The concentrations of Cd in liver and kidney increased significantly following exposure to Cd and the level continued to rise with the increase in exposure duration. Treatment of tank water with ascorbic acid, garlic or taurine significantly reduced the Cd concentrations in tissues compared to the positive control group, but the level in Cd exposed groups was greater than the negative control group. Fishes exposed to Cd and treated with ascorbic acid, garlic or taurine had reduced oxidative stress as evidenced from lower concentration of lipid peroxides and higher activities of superoxide dismutase and catalase in liver, kidney and erythrocytes compared to fishes exposed to Cd. The reduction in Cd induced oxidative stress was highest in ascorbic acid treated group followed by garlic and taurine treatment. The results suggest that ascorbic acid, garlic and taurine have potential to reduce tissue accumulation of Cd and associated oxidative stress in freshwater catfish.

  17. Ascorbic acid, garlic extract and taurine alleviate cadmium-induced oxidative stress in freshwater catfish (Clarias batrachus)

    International Nuclear Information System (INIS)

    An experiment was conducted to investigate bioaccumulation potential of cadmium (Cd) and changes in oxidative stress indices in liver and kidney tissues from Cd-exposed catfish (Clarias batrachus) with or without simultaneous treatment of water with ascorbic acid, garlic extract or taurine. C. batrachus (n = 324) with average length of 20 ± 4 cm and weight of 86 ± 5 g were used for the present investigation. Fishes were divided into nine groups (I to IX) each comprising 36 fishes. The fishes of groups II, III, IV and V were challenged with 5 ppm of cadmium chloride monohydrate (CdCl2.H2O), whereas groups VI, VII, VIII and IX were exposed to 10 ppm CdCl2.H2O solution for a period of 45 days. Group I was kept as negative control and the fishes of this group were maintained in water containing no added Cadmium. Group II and VI were maintained as Cd exposed non treated control to serve as positive controls. Fishes of III and VII, IV and VIII, V and IX received ascorbic acid (5 ppm), extract of dried garlic (5 ppm) or taurine (5 ppm), respectively during the entire experiment period. The concentrations of Cd in liver and kidney increased significantly following exposure to Cd and the level continued to rise with the increase in exposure duration. Treatment of tank water with ascorbic acid, garlic or taurine significantly reduced the Cd concentrations in tissues compared to the positive control group, but the level in Cd exposed groups was greater than the negative control group. Fishes exposed to Cd and treated with ascorbic acid, garlic or taurine had reduced oxidative stress as evidenced from lower concentration of lipid peroxides and higher activities of superoxide dismutase and catalase in liver, kidney and erythrocytes compared to fishes exposed to Cd. The reduction in Cd induced oxidative stress was highest in ascorbic acid treated group followed by garlic and taurine treatment. The results suggest that ascorbic acid, garlic and taurine have potential to reduce tissue accumulation of Cd and associated oxidative stress in freshwater catfish.

  18. Oral high dose ascorbic acid treatment for one year in young CMT1A patients: a randomised, double-blind, placebo-controlled phase II trial

    OpenAIRE

    de Visser Marianne; Baas Frank; Vermeulen Marinus; de Haan Rob J; Verhamme Camiel; van Schaik Ivo N

    2009-01-01

    Abstract Background High dose oral ascorbic acid substantially improved myelination and locomotor function in a Charcot-Marie-Tooth type 1A mouse model. A phase II study was warranted to investigate whether high dose ascorbic acid also has such a substantial effect on myelination in Charcot-Marie-Tooth type 1A patients and whether this treatment is safe. Methods Patients below age 25 years were randomly assigned to receive placebo or ascorbic acid (one gram twice daily) in a double-blind fash...

  19. Low-volume plus ascorbic acid vs high-volume plus simethicone bowel preparation before colonoscopy

    Directory of Open Access Journals (Sweden)

    Stefano Pontone

    2011-01-01

    Full Text Available AIM: To investigate the effectiveness of low-volume plus ascorbic acid [polyethylene glycol plus ascorbic acid (PEG + Asc] and high-volume plus simethicone [polyethylene glycol plus simethicone (PEG + Sim] bowel preparations. METHODS: A total of one hundred and forty-four outpatients (76 males, aged from 20 to 84 years (median age 59.5 years, who attended our Department, were divided into two groups, age and sex matched, and underwent colonoscopy. Two questionnaires, one for patients reporting acceptability and the other for endoscopists evaluating bowel cleansing effectiveness according to validated scales, were completed. Indications, timing of examination and endoscopical findings were recorded. Biopsy forceps were used as a measuring tool in order to determine polyp endoscopic size estimation. Difficulty in completing the preparation was rated in a 5-point Likert scale (1 = easy to 5 = unable. Adverse experiences (fullness, cramps, nausea, vomiting, abdominal pain, headache and insomnia, number of evacuations and types of activities performed during preparation (walking or resting in bed were also investigated. RESULTS: Seventy-two patients were selected for each group. The two groups were age and sex matched as well as being comparable in terms of medical history and drug therapies taken. Fourteen patients dropped out from the trial because they did not complete the preparation procedure. Ratings of global bowel cleansing examinations were considered to be adequate in 91% of PEG + Asc and 88% of PEG + Sim patients. Residual Stool Score indicated similar levels of amount and consistency of residual stool; there was a significant difference in the percentage of bowel wall visualization in favour of PEG + Sim patients. In the PEG + Sim group, 12 adenomas ≤ 10 mm diameter (5/left colon + 7/right colon vs 9 (8/left colon + 1/right colon in the PEG + Asc group were diagnosed. Visualization of small lesions seems to be one of the primary advantages of the PEG + Sim preparation. CONCLUSION: PEG + Asc is a good alternative solution as a bowel preparation but more improvements are necessary in order to achieve the target of a perfect preparation.

  20. Antiscorbutic activity of L-ascorbic acid 2-glucoside and its availability as a vitamin C supplement in normal rats and guinea pigs.

    Science.gov (United States)

    Yamamoto, I; Suga, S; Mitoh, Y; Tanaka, M; Muto, N

    1990-11-01

    Bioavailability of a newly-synthesized and chemically-stable 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G) as a vitamin C supplement was investigated in rats and guinea pigs. Oral administration of AA-2G to the animals resulted in an increase of serum ascorbic acid (AA) levels. However, in these sera the intact form was not detectable by the high performance liquid chromatography (HPLC) method, indicating its hydrolysis through the process of absorption. After an intravenous injection of AA-2G, the intact form diminished rapidly from the serum, followed by prolonged and marked elevation of serum AA levels. Various tissue homogenates from rats and guinea pigs were examined for their releasing activity of AA from AA-2G. High activity was observed in kidney, small intestine and serum of rats and in small intestine and kidney of guinea pigs. These hydrolytic activities were completely inhibited by castanospermine, a specific alpha-glucosidase inhibitor, suggesting the participation of alpha-glucosidase in the in vivo hydrolysis of AA-2G. AA-2G was found to exhibit obvious therapeutic effect in scorbutic guinea pigs by its repeated oral administrations. These results indicate that AA-2G is a readily available source of vitamin C activity in vivo. PMID:2093127

  1. Phytotoxicity of multi-walled carbon nanotubes on red spinach (Amaranthus tricolor L) and the role of ascorbic acid as an antioxidant

    International Nuclear Information System (INIS)

    Highlights: ? MWNTs are selected for study of the systemic toxicity and the potential influence on red spinach. ? Microscopic observation revealed some adverse effects on root and leaf. ? Cell damage were detected on 15 days after the exposure to MWNTs. ? ROS increase ceased once ascorbic acid was added into media. ? Oxidative stress seems to be the key element responsible for causing the toxicity. - Abstract: Carbon nanotubes (CNTs) are a novel nanomaterial with wide potential applications; however the adverse effects of CNTs following environmental exposure have recently received significant attention. Herein, we explore the systemic toxicity and potential influence of 0–1000 mg L?1 the multi-walled CNTs on red spinach. The multi-walled CNTs exposed plants exhibited growth inhibition and cell death after 15 days of hydroponic culture. The multi-walled CNTs had adverse effects on root and leaf morphology, as observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Raman spectroscopy detected the multi-walled CNTs in leaves. Biomarkers of nanoparticle toxicity, reactive oxygen species (ROS), and cell damage in the red spinach were greatly increased 15 days post-exposure to the multi-walled CNTs. These effects were reversed when the multi-walled CNTs were supplemented with ascorbic acid (AsA), suggesting a role of ROS in the multl-walled CNT-induced toxicity and that the primary mechanism of the multi-walled CNTs’ toxicity is oxidative stress.

  2. Hyaluronic acid depolymerization by ascorbate-redox effects on solid state cultivation of Streptococcus zooepidemicus in cashew apple fruit bagasse.

    Science.gov (United States)

    de Macedo, André Casimiro; Santana, Maria Helena Andrade

    2012-05-01

    The cashew fruit (Anacardium occidentale L.) has been used as a promising agricultural resource for the production of low-molecular weight (M(W)) hyaluronic acid (HA) (10(4)-10(5) Da). The cashew juice is a rich source of vitamin C containing, 1.2-2.0 g L(-1). This work explores the effects of the initial concentration of the ascorbate on the solid fermentation of the juice-moisturized bagasse from the cashew apple fruit. The results show that the M(W) reduction of HA is proportional to the initial ascorbate concentration. The presence of ascorbate did not influence the Streptococcus zooepidemicus metabolism. However, the HA productivity was increased from 0.18 to 0.28 mg g(-1) h(-1) when the ascorbate concentration ranged from 1.7 to 10 mg mL(-1). These findings contribute to the controlled production of HA in a low M(W) range, which is important in cell signalization, angiogenesis and nanoparticles production. PMID:22806044

  3. Facile synthesis of graphene hybrid tube-like structure for simultaneous detection of ascorbic acid, dopamine, uric acid and tryptophan

    International Nuclear Information System (INIS)

    Graphical abstract: A tube-like structure of graphene hybrid (GS–PTCA) was synthesized via π–π stacking interaction, and was used as modifier to fabricate electrode for simultaneous detection of ascorbic acid (AA), dopamine (DA), uric acid (UA) and tryptophan (Trp). SEM images of GS, PTCA and GS–PTCA were presented. Under the synergistic effects between GS and PTCA, the modified electrode displayed high catalytic activity and selectivity toward the oxidation of AA, DA, UA, and Trp. Highlights: ► A simple strategy for simultaneous detection of AA, DA, UA and Trp has been constructed. ► The tube-like structure of graphene hybrid (GS–PTCA) was synthesized. ► The GS–PTCA provided a selective interface for discrimination of AA, DA, UA and Trp. - Abstract: In the present work, a tube-like structure of graphene hybrid as modifier to fabricate electrode for simultaneous detection of ascorbic acid (AA), dopamine (DA), uric acid (UA) and tryptophan (Trp) was reported. The hybrid was synthesized by a simple method based on graphene sheets (GS) and 3,4,9,10-perylenetetracarboxylic acid (PTCA) via π–π stacking interaction under ultrasonic condition. The combination of GS and PTCA could effectively improve the dispersion of GS, owing to PTCA with the carboxylic-functionalized interface. Comparing with pure GS or PTCA modified electrode, GS–PTCA displayed high catalytic activity and selectivity toward the oxidation of AA, DA, UA, and Trp. Moreover, cyclic voltammetry, different pulse voltammetry and scanning electron microscopy were employed to characterize the sensors. The experiment results showed that the linear response range for simultaneous detection of AA, DA, UA, and Trp were 20–420 μM, 0.40–374 μM, 4–544 μM and 0.40–138 μM, respectively, and the detection limits were 5.60 μM, 0.13 μM, 0.92 μM and 0.06 μM (S/N = 3). Importantly, the proposed method offers promise for simple, rapid, selective and cost-effective analysis of small biomolecules.

  4. Facile synthesis of graphene hybrid tube-like structure for simultaneous detection of ascorbic acid, dopamine, uric acid and tryptophan

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Wen [Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Chai Yaqin, E-mail: yqchai@swu.edu.cn [Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Yuan Ruo, E-mail: yuanruo@swu.edu.cn [Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Chen Shihong; Han Jing; Yuan Dehua [Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China)

    2012-12-05

    Graphical abstract: A tube-like structure of graphene hybrid (GS-PTCA) was synthesized via {pi}-{pi} stacking interaction, and was used as modifier to fabricate electrode for simultaneous detection of ascorbic acid (AA), dopamine (DA), uric acid (UA) and tryptophan (Trp). SEM images of GS, PTCA and GS-PTCA were presented. Under the synergistic effects between GS and PTCA, the modified electrode displayed high catalytic activity and selectivity toward the oxidation of AA, DA, UA, and Trp. Highlights: Black-Right-Pointing-Pointer A simple strategy for simultaneous detection of AA, DA, UA and Trp has been constructed. Black-Right-Pointing-Pointer The tube-like structure of graphene hybrid (GS-PTCA) was synthesized. Black-Right-Pointing-Pointer The GS-PTCA provided a selective interface for discrimination of AA, DA, UA and Trp. - Abstract: In the present work, a tube-like structure of graphene hybrid as modifier to fabricate electrode for simultaneous detection of ascorbic acid (AA), dopamine (DA), uric acid (UA) and tryptophan (Trp) was reported. The hybrid was synthesized by a simple method based on graphene sheets (GS) and 3,4,9,10-perylenetetracarboxylic acid (PTCA) via {pi}-{pi} stacking interaction under ultrasonic condition. The combination of GS and PTCA could effectively improve the dispersion of GS, owing to PTCA with the carboxylic-functionalized interface. Comparing with pure GS or PTCA modified electrode, GS-PTCA displayed high catalytic activity and selectivity toward the oxidation of AA, DA, UA, and Trp. Moreover, cyclic voltammetry, different pulse voltammetry and scanning electron microscopy were employed to characterize the sensors. The experiment results showed that the linear response range for simultaneous detection of AA, DA, UA, and Trp were 20-420 {mu}M, 0.40-374 {mu}M, 4-544 {mu}M and 0.40-138 {mu}M, respectively, and the detection limits were 5.60 {mu}M, 0.13 {mu}M, 0.92 {mu}M and 0.06 {mu}M (S/N = 3). Importantly, the proposed method offers promise for simple, rapid, selective and cost-effective analysis of small biomolecules.

  5. The content determination of calcium, magnesium and ascorbic acid in sea buckthorn fruits at vulcan coal dump

    Directory of Open Access Journals (Sweden)

    Andreea BRASOVAN

    2009-11-01

    Full Text Available The study presents data on content determination of calcium, magnesium and ascorbic acid in sea buckthorn fruits collected from Vulcan coal dump. The dump was never covered with soil or fertilizers containing azoth, potassium and phosphorus. The sea buckthorn was planted directly on the sterile and it has an important function in stabilizing the acclivity and fixing the atmospheric azoth with the nodosities on the roots. So, the sea buckthorn becomes widespread plant in coal dumps because it helps to the soil formation. The results obtained after the determination of calcium, magnesium and ascorbic acid from the fruits of this plant were compared with the values already reported in various references, concluding that these differences are insignificant (3.7% for magnesium and 9.4% for calcium. Therefore, the sea buckthorn from the dump can be used in food industry, as well as in pharmaceutics and medicine.

  6. Direct electron transfer of ferritin in dihexadecylphosphate on an Au film electrode and its catalytic oxidation toward ascorbic acid

    International Nuclear Information System (INIS)

    Stable thin films were obtained by casting vesicle dispersion of dihexadecylphosphate (DHP) containing ferritin onto the nanometer Au film electrode. Ferritin in DHP films exhibited a well-defined current-potential curve. The voltammetric behavior of ferritin and the stability of the ferritin-DHP modified Au film electrode were investigated. UV-vis and reflctance absorbance infrared spectra indicated that ferritin retained near-native secondary structure in the DHP films. The loading and unloading of ferritin iron into the apoferritin shell were investigated by cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM). The results showed that iron exited the apoferritin shell when reduced, and entered into it when oxidized. Ferritin in DHP films exhibited a strong electrocatalytic activity toward the oxidation of ascorbic acid, which resulted in lowering 330 mV overpotential and greatly increasing the oxidation peak current. Based on this procedure, an amperometric method for the determination of ascorbic acid was proposed

  7. Conclusion on the peer review of the pesticide risk assessment of the active substance L-ascorbic acid

    Directory of Open Access Journals (Sweden)

    European Food Safety Authority

    2013-04-01

    Full Text Available The conclusions of the European Food Safety Authority (EFSA following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State the Netherlands, for the pesticide active substance L-ascorbic acid are reported. The context of the peer review was that required by Commission Regulation (EU No 188/2011. The conclusions were reached on the basis of the evaluation of the representative uses of L-ascorbic acid as a fungicide on potato, glasshouse tomato and field and glasshouse flower bulbs. The reliable endpoints concluded as being appropriate for use in regulatory risk assessment, derived from the available studies and literature in the dossier peer reviewed, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified.

  8. Regulation of ascorbic acid metabolism by blue LED light irradiation in citrus juice sacs.

    Science.gov (United States)

    Zhang, Lancui; Ma, Gang; Yamawaki, Kazuki; Ikoma, Yoshinori; Matsumoto, Hikaru; Yoshioka, Terutaka; Ohta, Satoshi; Kato, Masaya

    2015-04-01

    In the present study, the effects of red and blue LED lights on the accumulation of ascorbic acid (AsA) were investigated in the juice sacs of three citrus varieties, Satsuma mandarin, Valencia orange, and Lisbon lemon. The results showed that the blue LED light treatment effectively increased the AsA content in the juice sacs of the three citrus varieties, whereas the red LED light treatment did not. By increasing the blue LED light intensity, the juice sacs of the three citrus varieties accumulated more AsA. Moreover, continuous irradiation with blue LED light was more effective than pulsed irradiation for increasing the AsA content in the juice sacs of the three citrus varieties. Gene expression results showed that the modulation of AsA accumulation by blue LED light was highly regulated at the transcription level. The up-regulation of AsA biosynthetic genes (CitVTC1, CitVTC2, CitVTC4, and CitGLDH), AsA regeneration genes (CitMDAR1, CitMDAR2, and CitDHAR) and two GSH-producing genes (CitGR and CitchGR) contributed to these increases in the AsA content in the three citrus varieties. PMID:25711821

  9. SCREEN-PRINTED ELECTRODE MODIFIED WITH SILVER HEXACY ANOFERRATE-NAFION® FOR ASCORBIC ACID DETERMINATION

    Directory of Open Access Journals (Sweden)

    I.L MATTOS

    2011-01-01

    Full Text Available A flow injection system using a new and/or re-used graphite screen-printed electrode modified with silver hexacyanoferrate and a Nafion® polymer layer (AgHCF/GSPE was employed for the determination of ascorbic acid in orange juice and drugs samples. Both modified electrodes showed an initial sensitivity of 0.015 A.cm²־.M¹־, with a linear response over the range from 50 to 300 mg L¹ , relative standard deviations smaller than 2%, detection and quantification limits of c.a. 5.0 and 25.0 mg.L¹. The response of the electrodes was stable, with no variation of base line after 6-8 hours of continuous operation. With this system it is possible to measure 65-70 samples (20μΚ per hour. By using 1.06 mg of AgNO3, 4.12 mg of K3Fe(CN6, 50.5 mg of KNO3 and 800μL of HNO3, it is possible to obtain between 25 and 30 modified electrodes. The proposed system showed to be inexpensive, versatile, robust and suitable for industrial application. The surface morphology of the bare and/or modified graphite screen-printed electrode was characterized by scanning electron microscopy.

  10. Evidence for the safety of ascorbic acid administration to the premature infant.

    Science.gov (United States)

    Bass, W T; Malati, N; Castle, M C; White, L E

    1998-02-01

    Ascorbic acid (AA), a plasma antioxidant, is maintained at high levels in premature fetal blood and declines rapidly postpartum. The sudden reduction in blood AA levels secondary to premature delivery may increase the risk of oxidant injury, that is, bronchopulmonary dysplasia and intraventricular hemorrhage. There is concern that administration of AA to premature infants, in an effort to increase antioxidant capacity, may cause hemolysis. We felt that the benefits of early AA administration and prevention of the immediate postnatal drop in blood AA levels, might outweigh the risks of erthrocyte damage. Fifty one high-risk premature infants were randomized to receive either normal saline or 100 mg/kg of AA, daily for the first week of life. Double-blind comparisons were made of hemoglobin, hematocrit, erythrocyte morphology, bilirubin, number of blood transfusions and days of phototherapy, renal function tests, the incidence of infection, bronchopulmonary dysplasia, and intraventricular hemorrhage during the first month of life. The administration of AA prevented the immediate postnatal drop in AA and was not associated with evidence of increased hemolysis. No significant differences in renal function, rate of infection, bronchopulmonary dysplasia, or intraventricular hemorrhage were seen between the two groups. This study suggests that AA administration to the premature infant is safe and supports the designing and performance of larger clinical studies of the antioxidant properties of AA. PMID:9514139

  11. Polyethyleneimine-templated copper nanoclusters via ascorbic acid reduction approach as ferric ion sensor

    International Nuclear Information System (INIS)

    Highlights: • A new method for synthesis of the BPEI-CuNCs is established. • A facile approach for Fe3+ ion sensing by fluorescence quenching is developed. • The method for Fe3+ sensing has high sensitivity and excellent selectivity. - Abstract: In this report we reported a facile one-pot method for synthesis of water-soluble and stable fluorescent CuNCs at room temperature, in which branched polyethyleneimine (BPEI) served as capping scaffold and ascorbic acid as reducing agent. The prepared BPEI-CuNCs exhibited excellent properties such as good water-solubility, photostability and high stability toward high ionic strength. Based on the electron transfer induced fluorescence quenching mechanism, this fluorescence probe was used for the sensitive and selective determination of ferric ions (Fe3+) in aqueous solution. The limit of detection was 340 nM in the linear range of 0.5–1000 ?M, which was lower than the maximum level of Fe3+ permitted in drinking water by the U.S. Environmental Protection Agency. The method was successfully applied to the detection of Fe3+ in tap water, Yellow River water and human urine samples with the quantitative spike recoveries ranging from 95.3% to 112.0%

  12. Enhancement of Dopaminergic Differentiation in Proliferating Midbrain Neuroblasts by Sonic Hedgehog and Ascorbic Acid

    Science.gov (United States)

    Volpicelli, Floriana; Consales, Claudia; Caiazzo, Massimiliano; Colucci-D'Amato, Luca; Perrone-Capano, Carla; di Porzio, Umberto

    2004-01-01

    We analyzed the molecular mechanisms involved in the acquisition and maturation of dopaminergic (DA) neurons generated in vitro from rat ventral mesencephalon (MES) cells in the presence of mitogens or specific signaling molecules. The addition of basic fibroblast growth factor (bFGF) to MES cells in serum-free medium stimulates the proliferation of neuroblasts but delays DA differentiation. Recombinant Sonic hedgehog (SHH) protein increases up to three fold the number of tyrosine hydroxylase (TH)-positive cells and their differentiation, an effect abolished by anti-SHH antibodies. The expanded cultures are rich in nestin-positive neurons, glial cells are rare, all TH+ neurons are DA, and all DA and GABAergic markers analyzed are expressed. Adding ascorbic acid to bFGF/SHH-treated cultures resulted in a further five- to seven-fold enhancement of viable DA neurons. This experimental system also provides a powerful tool to generate DA neurons from single embryos. Our strategy provides an enriched source of MES DA neurons that are useful for analyzing molecular mechanisms controlling their function and for experimental regenerative approaches in DA dysfunction. PMID:15303305

  13. Exogenous application of ascorbic acid alleviates chilling injury in apricot (Prunus armeniaca L. cv. Shahroudi flowers

    Directory of Open Access Journals (Sweden)

    Hassan Bayat

    2013-08-01

    Full Text Available One of the most important limiting factors in spread of apricot in Iran is late spring frost, which damages flower bud and decrease total yield of crop. It has been found that ascorbic acid (AA plays a beneficial role during plant response to chilling and freezing stresses. To evaluate the effects of AA on alleviating of cold stress, the flower buds of Prunus armeniaca L. cv. Shahroudi were sprayed at pink cluster stage with AS at 4 levels (0, 100, 200 and 300 mg. L-1 and were then exposed to artificial cold stress (4 h at –4 °C or without cold stress (+ 25°C. Experimental attributes including electrolyte leakage (EL of flower buds and percentage of damage of pistil, anthers and petals to temperature treatments were determined. The results showed that at - 4°C the lowest and highest percentage of damage and EL of flower buds were observed in application of 200 and 0 mg. L-1 AA, respectively. The highest and lowest percentage of damage of flower organs and EL were obtained in application of 300 and 200 mg. L-1 AA, respectively at + 25 °C. Based on the results of this experiment, AA alleviates the negative effect of cold stress on EL and flower organ damages in apricot cv. Shahroudi, depending on the concentrations of AA used.

  14. A novel automated electrochemical ascorbic acid assay in the 24-well microtiter plate format.

    Science.gov (United States)

    Intarakamhang, Sireerat; Leson, Christian; Schuhmann, Wolfgang; Schulte, Albert

    2011-02-14

    Automatic ascorbic acid (AA) voltammetry was established in 24-well microtiter plates. The assay used a movable assembly of a pencil rod working, an Ag/AgCl reference and a Pt counter electrode with differential pulse voltammetry (DPV) for concentration-dependent current generation. A computer was in command of electrode (z) and microtiter plate (x, y) positioning and timed potentiostat operation. Synchronization of these actions supported sequential approach of all wells and subsequent execution of electrode treatment procedures or AA voltammetry at defined intervals in a measuring cycle. DPV in well solutions offered a linear current/concentration range between 0.1 and 8.0 mM, a sensitivity of about 1 ?A mM(-1) AA, and a detection limit of 50 ?M. When used with a calibration curve or standard addition, automated voltammetry of samples with added known amounts of AA demonstrated good recovery rates. Also, the assay achieved the accurate determination of the AA content of vitamin C tablets, a fruit juice and an herbal tea extract. Robotic AA voltammetry has the advantage of conveniently handling multiple samples in a single measuring run without the continuous attention of laboratory personnel. It is a good option when the goal is cost-effective AA screening of sample libraries and has potential for applications in health care and the food processing, cosmetic and pharmaceutical industries. PMID:21241840

  15. SCREEN-PRINTED ELECTRODE MODIFIED WITH SILVER HEXACY ANOFERRATE-NAFION® FOR ASCORBIC ACID DETERMINATION

    Scientific Electronic Library Online (English)

    I.L, MATTOS; F, PADILLA; J. H, ZAGAL; E.H.L, FALCAO; R, SEGURA.

    Full Text Available A flow injection system using a new and/or re-used graphite screen-printed electrode modified with silver hexacyanoferrate and a Nafion® polymer layer (AgHCF/GSPE) was employed for the determination of ascorbic acid in orange juice and drugs samples. Both modified electrodes showed an initial sensit [...] ivity of 0.015 A.cm²?.M¹?, with a linear response over the range from 50 to 300 mg L¹ , relative standard deviations smaller than 2%, detection and quantification limits of c.a. 5.0 and 25.0 mg.L¹. The response of the electrodes was stable, with no variation of base line after 6-8 hours of continuous operation. With this system it is possible to measure 65-70 samples (20??) per hour. By using 1.06 mg of AgNO3, 4.12 mg of K3Fe(CN)6, 50.5 mg of KNO3 and 800?L of HNO3, it is possible to obtain between 25 and 30 modified electrodes. The proposed system showed to be inexpensive, versatile, robust and suitable for industrial application. The surface morphology of the bare and/or modified graphite screen-printed electrode was characterized by scanning electron microscopy.

  16. Simultaneous Chronoamperometric Sensing of Ascorbic Acid and Acetaminophen at a Boron-Doped Diamond Electrode

    Science.gov (United States)

    Cofan, Codru?a; Radovan, Ciprian

    2008-01-01

    Cyclic voltammetry (CV) and chronoamperometry (CA) have been used to sense and determine simultaneously L-ascorbic acid (AA) and acetaminophen (AC) at a boron-doped diamond electrode (BDDE) in a Britton-Robinson buffer solution. The calibration plots of anodic current peak versus concentration obtained from CV and CA data for both investigated compounds in single and di-component solutions over the concentration range 0.01 mM – 0.1 mM proved to be linear, with very good correlation parameters. Sensitivity values and RSD of 2-3% were obtained for various situations, involving both individual and simultaneous presence of AA and AC. The chronoamperometric technique associated with standard addition in sequential one step and/or two successive and continuous chronoamperograms at two characteristic potential levels represented a feasible option for the simultaneous determination of AA and AC in real sample systems such as pharmaceutical formulations. The average values indicated by the supplier were confirmed to a very close approximation from chronoamperomgrams by using several additions with the application of suitable current correction factors.

  17. Polyethyleneimine-templated copper nanoclusters via ascorbic acid reduction approach as ferric ion sensor

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Jie; Ju, Yuyun; Liu, Juanjuan; Zhang, Huige [State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Chen, Xingguo, E-mail: chenxg@lzu.edu.cn [State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou 730000 (China)

    2015-01-07

    Highlights: • A new method for synthesis of the BPEI-CuNCs is established. • A facile approach for Fe{sup 3+} ion sensing by fluorescence quenching is developed. • The method for Fe{sup 3+} sensing has high sensitivity and excellent selectivity. - Abstract: In this report we reported a facile one-pot method for synthesis of water-soluble and stable fluorescent CuNCs at room temperature, in which branched polyethyleneimine (BPEI) served as capping scaffold and ascorbic acid as reducing agent. The prepared BPEI-CuNCs exhibited excellent properties such as good water-solubility, photostability and high stability toward high ionic strength. Based on the electron transfer induced fluorescence quenching mechanism, this fluorescence probe was used for the sensitive and selective determination of ferric ions (Fe{sup 3+}) in aqueous solution. The limit of detection was 340 nM in the linear range of 0.5–1000 ?M, which was lower than the maximum level of Fe{sup 3+} permitted in drinking water by the U.S. Environmental Protection Agency. The method was successfully applied to the detection of Fe{sup 3+} in tap water, Yellow River water and human urine samples with the quantitative spike recoveries ranging from 95.3% to 112.0%.

  18. Electrochemical determination of ascorbic acid at p-phenylenediamine film-holes modified glassy carbon electrode

    Directory of Open Access Journals (Sweden)

    Olana Bikila Nagasa

    2015-01-01

    Full Text Available In this work the determination of ascorbic acid (AA at glassy carbon electrode (GCE modified with a perforated film produced by reduction of diazonium generated in situ from p-phenylenediamine (PD is reported. Holes were intentionally created in the modifier film by stripping a pre-deposited gold nanoparticles. The modified electrodes were electrochemically characterized by common redox probes: hydroquinone, ferrocyanide and hexamineruthenium(III. The cyclic voltammetric and amperometric response of AA using the modified electrodes was compared with that of bare GCE. The bare GCE showed a linear response to AA in the concentration range of 5 mM to 45 mM with detection limit of 1.656 mM and the modified GCE showed a linear response to AA in the concentration range of 5 μM to 45 μM with detection limit of 0.123 μM. The effect of potential intereferents on amperometric signal of AA at the modified GCE was examined and found to be minimal. The inter-electrode reproducibility, stability, and accuracy were determined. The modified electrode showed excellent inter-electrode reproducibility, accuracy and stability. The modified electrode reported is a promising candidate for use in electroanalysis of AA.

  19. Uptake and release of adrenal ascorbic acid in the guinea pig after injection of ACTH

    International Nuclear Information System (INIS)

    The effect of a single injection of ACTH (3 IU/100 g body weight) on the distribution of ascorbic acid (AA) and radiolabeled AA in 20 tissues was studied in adult male guinea pigs consuming 500 mg AA/kg diet. Saline- or ACTH-injected animals were simultaneously injected with [1-14C]AA, and killed at 0.5, 1, 2, 4 and 6 h after injection. There was no significant difference between treatments in the weight of any tissue over the 6-h experimental period. As anticipated, the concentration of AA in the adrenals of animals injected with ACTH was 33% of that of animals injected with saline at 4 h. Unexpectedly, the concentration of radiolabeled AA in the adrenals at 0.5 h after ACTH injection was 172% of that after saline injection. The concentration of radiolabeled AA in the adrenal of the saline-injected animals increased slowly over time to reach a level similar to that of ACTH-injected animals by 6 h. There was no effect of ACTH on the level of AA or uptake in any of the other tissues examined. These results demonstrate that a single dose of ACTH markedly influences the retention of AA in the adrenal gland without similarly altering retention of AA in other tissues. Furthermore, ACTH treatment causes both accelerated uptake and release of AA into the adrenals

  20. Stereological studies of the effects of sodium benzoate or ascorbic acid on rats’ cerebellum

    Science.gov (United States)

    Noorafshan, Ali; Erfanizadeh, Mahboobeh; Karbalay-Doust, Saied

    2014-01-01

    Objectives: To evaluate the cerebellar structure in sodium benzoate (NaB) or ascorbic acid (AA) treated rats. Methods: This experimental study was conducted between May and September 2013 in the Laboratory Animal Center of Shiraz University of Medical Sciences, Shiraz, Iran. The rats received distilled either water, NaB (200mg/kg/day), AA (100mg/kg/day), or NaB+AA. The hemispheres were removed after 28 days and underwent quantitative study. Results: The total volume of the cerebellar hemisphere, its cortex, intracerebellar nuclei; the total number of the Purkinje, Bergman, granule, neurons, and glial cells of the molecular layer; and neurons and glial cells of the intracerebellar nuclei reduced by 21-52% in the NaB-treated rats compared with the distilled water group (p=0.004). The total number of the Purkinje, Bergman, Golgi, and granule cells was 29-45% higher in the AA-treated rats compared with the distilled water group (p=0.05). However, these measures reduced by 17-50% in the NaB+AA-treated rats compared with the distilled water group (p=0.004). The NaB+AA group did not induce any significant structural changes in comparison with the NaB group (p>0.05). Conclusions: The NaB exposure with or without AA treatment could alter the cerebellum. Yet, AA could prevent the loss of some cells in the cerebellum. PMID:25491215

  1. Elimination of ascorbic acid after high-dose infusion in prostate cancer patients : a pharmacokinetic evaluation

    DEFF Research Database (Denmark)

    Nielsen, Torben Kjær; HØjgaard, Martin

    2015-01-01

    Treatment with high-dose intravenous (IV) ascorbic acid (AA) is used in complementary and alternative medicine for various conditions including cancer. Cytotoxicity to cancer cell lines has been observed with millimolar concentrations of AA. Little is known about the pharmacokinetics of high dose IV AA. The purpose of the present study was to assess the basic kinetic variables in human beings over a relevant AA dosing interval for proper design of future clinical trials. Ten patients with metastatic prostate cancer were treated for four weeks with fixed AA doses of 5, 30 and 60 g. AA was measured consecutively in plasma and indicated first-order elimination kinetics throughout the dosing range with supra-physiological concentrations. The target dose of 60g AA IV produced a peak plasma AA concentration of 20.3 mM. Elimination half-life was 1.87 hr (mean, SD ± 0.40), volume of distribution 0.19 L/kg (SD ±0.05) and clearance rate 6.02 L/hr (100mL/min). No differences in pharmacokinetic parameters were observed between weeks/doses. A relatively fast first-order elimination with half-life of about 2 hr makes it impossible to maintain AA concentrations in the potential cytotoxic range after infusion stop in prostate cancer patients with normal kidney function. We propose a regimen with a bolus loading followed by a maintenance infusion based on the calculated clearance. This article is protected by copyright. All rights reserved.

  2. Elimination of Ascorbic Acid following High-Dose Infusion in Prostate Cancer Patients : A Pharmacokinetic Evaluation

    DEFF Research Database (Denmark)

    Kjær Nielsen, Torben; HØjgaard, Martin

    2015-01-01

    Treatment with high-dose intravenous (IV) ascorbic acid (AA) is used in complementary and alternative medicine for various conditions including cancer. Cytotoxicity to cancer cell lines has been observed with millimolar concentrations of AA. Little is known about the pharmacokinetics of high dose IV AA. The purpose of the present study was to assess the basic kinetic variables in human beings over a relevant AA dosing interval for proper design of future clinical trials. Ten patients with metastatic prostate cancer were treated for four weeks with fixed AA doses of 5, 30 and 60 g. AA was measured consecutively in plasma and indicated first-order elimination kinetics throughout the dosing range with supra-physiological concentrations. The target dose of 60g AA IV produced a peak plasma AA concentration of 20.3 mM. Elimination half-life was 1.87 hr (mean, SD ± 0.40), volume of distribution 0.19 L/kg (SD ±0.05) and clearance rate 6.02 L/hr (100mL/min). No differences in pharmacokinetic parameters were observed between weeks/doses. A relatively fast first-order elimination with half-life of about 2 hr makes it impossible to maintain AA concentrations in the potential cytotoxic range after infusion stop in prostate cancer patients with normal kidney function. We propose a regimen with a bolus loading followed by a maintenance infusion based on the calculated clearance. This article is protected by copyright. All rights reserved.

  3. Chronic nickel-induced DNA damage and cell death: the protection role of ascorbic acid.

    Science.gov (United States)

    Jia, Jie; Chen, Jie

    2008-06-01

    High consumption of nickel-containing products leads to more exposure of humans to nickel and its by-products. Except the lethal effect of acute nickel poison, chronic nickel exposure is also harmful to humans, but the mechanism of chronic nickel-induced cytotoxicity remains unclear. Here, we found that long-term exposure of Ni(2+) led to significant DNA fragmentation, cell death, and reactive oxygen species (ROS) generation in human leukemia HL-60 cells. Induction of Ni(2+) on DNA fragmentation and cell death could be prevented by the antioxidants ascorbic acid (ASA) or N-acetyl-cysteine (NAC), or enhanced by H(2)O(2), indicating the involvement of ROS generation in the chronic nickel cytotoxicity in cells. Long-term exposure of mice to low Ni(2+) also led to a significant increase in both the ROS generation in the serum and the DNA fragmentation in the peripheral blood mononuclear cells (PBMC), while coadministration of ASA with Ni(2+) together significantly decreased both the DNA fragmentation and the ROS generation. Collectively, these results proved that ROS generation is at least one mechanism of the cytotoxicity of chronic nickel exposure, while ASA is probably useful for people to prevent the chronic nickel cytotoxicity, especially for those who work or live near a mining area or a factory related with nickel. PMID:18214889

  4. Simultaneous Chronoamperometric Sensing of Ascorbic Acid and Acetaminophen at a Boron-Doped Diamond Electrode

    Directory of Open Access Journals (Sweden)

    Ciprian Radovan

    2008-06-01

    Full Text Available Cyclic voltammetry (CV and chronoamperometry (CA have been used to sense and determine simultaneously L-ascorbic acid (AA and acetaminophen (AC at a boron-doped diamond electrode (BDDE in a Britton-Robinson buffer solution. The calibration plots of anodic current peak versus concentration obtained from CV and CA data for both investigated compounds in single and di-component solutions over the concentration range 0.01 mM – 0.1 mM proved to be linear, with very good correlation parameters. Sensitivity values and RSD of 2-3% were obtained for various situations, involving both individual and simultaneous presence of AA and AC. The chronoamperometric technique associated with standard addition in sequential one step and/or two successive and continuous chronoamperograms at two characteristic potential levels represented a feasible option for the simultaneous determination of AA and AC in real sample systems such as pharmaceutical formulations. The average values indicated by the supplier were confirmed to a very close approximation from chronoamperomgrams by using several additions with the application of suitable current correction factors.

  5. D-penicillamine-templated copper nanoparticles via ascorbic acid reduction as a mercury ion sensor.

    Science.gov (United States)

    Lin, Shu Min; Geng, Shuo; Li, Na; Li, Nian Bing; Luo, Hong Qun

    2016-05-01

    Mercury ion is one of the most hazardous metal pollutants that can cause deleterious effects on human health and the environment even at low concentrations. It is necessary to develop new mercury detection methods with high sensitivity, specificity and rapidity. In this study, a novel and green strategy for synthesizing D-penicillamine-capped copper nanoparticles (DPA-CuNPs) was successfully established by a chemical reduction method, in which D-penicillamine and ascorbic acid were used as stabilizing agent and reducing agent, respectively. The as-prepared DPA-CuNPs showed strong red fluorescence and had a large Stoke's shift (270nm). Scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, fluorescence spectroscopy, and ultraviolet-visible spectrophotometry were utilized to elucidate the possible fluorescence mechanism, which could be aggregation-induced emission effect. Based on the phenomenon that trace mercury ion can disperse the aggregated DPA-CuNPs, resulting in great fluorescence quench of the system, a sensitive and selective assay for mercury ion in aqueous solution with the DPA-CuNPs was developed. Under optimum conditions, this assay can be applied to the quantification of Hg(2+) in the 1.0-30μM concentration range and the detection limit (3σ/slope) is 32nM. The method was successfully applied to determine Hg(2+) in real water samples. PMID:26946016

  6. Effects of Socio demographic factors on plasma ascorbic acid and alpha tocopherol anti oxidants during pregnancy

    International Nuclear Information System (INIS)

    Objectives: To assess the plasma levels of vitamins C and E at the various stages of pregnancy and to correlate their plasma levels with the socio-demographic factors of pregnant Nigerians. Methodology: The pregnant cases (n=180) were randomly selected according to gestational ages. And the controls (n=20) were non-pregnant women of the same age. Plasma levels of both vitamins were assayed with well established laboratory methods. Results: The mean plasma vitamins C and E in the pregnant cases was lower (by 17-23%) than controls across the three trimesters, p<0.0001. The correlation of vitamin C versus maternal age was significant; r = - 0.59, p<0.05; the mean plasma level of vitamin C declined by 57% as the maternal age increases from 22-37 years. Conclusion: The mean plasma Ascorbic acid and Alpha-tocopherol are reduced during pregnancy and socio-demographic factors have mild effects on the plasma levels of these vitamins. (author)

  7. A miniature glucose/O{sub 2} biofuel cell with a high tolerance against ascorbic acid

    Energy Technology Data Exchange (ETDEWEB)

    Li, X.; Zhang, L. [Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing (China); Graduate School of CAS, Beijing (China); Su, L. [Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing (China); Ohsaka, T. [Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Midori-ku, Yokohama (Japan); Mao, L.

    2009-02-15

    This study demonstrates a miniature glucose/O{sub 2} biofuel cell (BFC) with a high tolerance against physiological level of ascorbic acid (AA) by immobilising ascorbate oxidase (AAox) on both the bioanode and the biocathode. Single-walled carbon nanotube (SWNT)-modified carbon fiber microelectrodes (CFMEs) are employed as the substrate electrode for the bioanode and biocathode. Glucose dehydrogenase (GDH) and bilirubin oxidase (BOD) are used as the biocatalysts for the electro-oxidation of glucose and for the electro-reduction of oxygen, respectively. SWNTs are used as the support for the both, stably confining the electrocatalyst (i.e. polymerised methylene blue, polyMB) for the oxidation of NADH co-factor for GDH and efficiently facilitating direct electrochemistry of the cathodic biocatalyst (i.e. BOD) for O{sub 2} reduction. The prepared micro-sized GDH-based bioanode and BOD-based biocathode employed for the bioelectrocatalytic oxidation of glucose and reduction of oxygen, respectively, are further over-coated with AAox to give a miniature glucose/O{sub 2} BFC with a high tolerance against AA. The maximum power density and the open circuit voltage (OCV) of the assembled glucose/O{sub 2} BFC are 52 {mu}W cm{sup -2} and 0.60 V, respectively. These values remain unchanged with the presence of AA in solution. In the human serum containing 10 mM NAD{sup +} and under ambient air, the maximum power density and the OCV of the assembled glucose/O{sub 2} BFC with AAox immobilisation on both the bioanode and the biocathode are 35 {mu}W cm{sup -2} and 0.39 V, respectively. These values are remarkably larger than those of the glucose/O{sub 2} BFC without AAox immobilisation on both the bioanode and the biocathode. This study could offer a new route to the development of enzymatic BFCs with promising application in real biological systems. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  8. Glassy carbon electrodes modified with multiwalled carbon nanotubes for the determination of ascorbic acid by square-wave voltammetry

    Directory of Open Access Journals (Sweden)

    Sushil Kumar

    2012-05-01

    Full Text Available Multiwalled carbon nanotubes were used to modify the surface of a glassy carbon electrode to enhance its electroactivity. Nafion served to immobilise the carbon nanotubes on the electrode surface. The modified electrode was used to develop an analytical method for the analysis of ascorbic acid (AA by square-wave voltammetry (SWV. The oxidation of ascorbic acid at the modified glassy carbon electrode showed a peak potential at 315 mV, about 80 mV lower than that observed at the bare (unmodified electrode. The peak current was about threefold higher than the response at the bare electrode. Replicate measurements of peak currents showed good precision (3% rsd. Peak currents increased with increasing ascorbic acid concentration (dynamic range = 0.0047–5.0 mmol/L and displayed good linearity (R2 = 0.994. The limit of detection was 1.4 μmol/L AA, while the limit of quantitation was 4.7 μmol/L AA. The modified electrode was applied to the determination of the amount of ascorbic acid in four brands of commercial orange-juice products. The measured content agreed well (96–104% with the product label claim for all brands tested. Recovery tests on spiked samples of orange juice showed good recovery (99–104%. The reliability of the SWV method was validated by conducting parallel experiments based on high-performance liquid chromatography (HPLC with absorbance detection. The observed mean AA contents of the commercial orange juice samples obtained by the two methods were compared statistically and were found to have no significant difference (P = 0.05.

  9. The content determination of calcium, magnesium and ascorbic acid in sea buckthorn fruits at vulcan coal dump

    OpenAIRE

    Andreea BRASOVAN; Codrea, Vlad; Vasilica MÂNDROC; Ramona CÂMPEAN; Neli OLAH

    2009-01-01

    The study presents data on content determination of calcium, magnesium and ascorbic acid in sea buckthorn fruits collected from Vulcan coal dump. The dump was never covered with soil or fertilizers containing azoth, potassium and phosphorus. The sea buckthorn was planted directly on the sterile and it has an important function in stabilizing the acclivity and fixing the atmospheric azoth with the nodosities on the roots. So, the sea buckthorn becomes widespread plant in coal dumps because it ...

  10. Hepatotoxicity of Pentavalent Antimonial Drug: Possible Role of Residual Sb(III) and Protective Effect of Ascorbic Acid

    OpenAIRE

    Kato, Kelly C.; Morais-Teixeira, Eliane; Priscila G. Reis; Silva-Barcellos, Neila M.; Salaün, Pascal; Campos, Paula P.; Dias Corrêa-Junior, José; Rabello, Ana; Demicheli, Cynthia; Frézard, Frédéric

    2014-01-01

    Pentavalent antimonial drugs such as meglumine antimoniate (Glucantime [Glu; Sanofi-Aventis, São Paulo, Brazil]) produce severe side effects, including cardiotoxicity and hepatotoxicity, during the treatment of leishmaniasis. We evaluated the role of residual Sb(III) in the hepatotoxicity of meglumine antimoniate, as well as the protective effect of the antioxidant ascorbic acid (AA) during antimonial chemotherapy in a murine model of visceral leishmaniasis. BALB/c mice infected with Leishman...

  11. Stimulative Effects of Ascorbic Acid, Thiamin or Pyridoxine on Vicia faba Growth and Some Related Metabolic Activities

    Directory of Open Access Journals (Sweden)

    A. M. Hamada

    2000-01-01

    Full Text Available Soaking of bean seeds in 100 ppm ascorbic acid, thiamin or pyridoxine induced a stimulation effect on germination. Also, soaking of seeds or spraying of bean seedlings (25 day old with 100 ppm of each of these vitamins, stimulated fresh and dry weight, biosynthesis of photosynthetic pigment fractions and net photosynthetic rate. However, these treatments did not induce a considerable change in dark respiration.

  12. Terminal ileum submucous plexus: Study of the VIP-ergic neurons of diabetic rats treated with ascorbic acid

    OpenAIRE

    Zanoni Jacqueline Nelisis; Hernandes Luzmarina; Bazotte Roberto Barbosa; Miranda Neto Marcílio Hubner de

    2002-01-01

    The aim of this study was to evaluate the effect of the ascorbic acid (AA) supplementation on the neurons that produce the vasoactive intestinal peptide (VIP) in the submucous plexus of the ileum of rat, four months after the induction of experimental diabetes mellitus with streptozotocin. Three groups of rats were used: C - control, D - diabetic, DA - diabetic receiving AA. We have measured the immunoreactivity and area of 80 cellular bodies of VIP-ergic neurons from each studied group. In t...

  13. Dynamical properties in uniform and periodic growth modes of ascorbic acid crystal domain from thin solution film

    OpenAIRE

    Yamazaki, Yoshihiro; Kikuchi, Mitsunobu; Toda, Akihiko; Wakita, Jun-ichi; Matsushita, Mitsugu

    2013-01-01

    There exists the threshold-sensitive dynamical transition between the uniform and the periodic growth modes in the domain growth of ascorbic acid crystals from its aqueous supersaturated solution film. The crystal growth induces the solution flow. Humidity controls the fluidity of the solution. The solution flow varies the film thickness. The threshold exists in the thickness of the solution film, and the crystal growth almost stops if the thickness becomes lower than the th...

  14. Optimum Efficiency of Photogalvanic Cell for Solar Energy Conversion: Lissamine Green B-Ascorbic Acid-NaLS System

    OpenAIRE

    Kishna Ram Genwa; Kewal Singh

    2013-01-01

    Photogalvanic cells are photoelectrochemical cells chargeable in light for solar energy conversion and storage. They may be energy source for the future, if their electrical performance is increased. In this study, a photosensitizer Lissamine green B, a reductant Ascorbic acid and a surfactant NaLS have been used in the photogalvanic cell. The generated photopotential and photocurrent are 850.0 mV and 375.0 ?A respectively. The conversion efficiency of the cell, fill factor and the cell perfo...

  15. Redox cycles of vitamin E: Hydrolysis and ascorbic acid dependent reduction of 8a-(alkyldioxy)tocopherones

    International Nuclear Information System (INIS)

    Oxidation of the biological antioxidant ?-tocopherol (vitamin E; TH) by peroxyl radicals yields 8a-(alkyldioxy)tocopherones, which either may hydrolyze to ?-tocopheryl quinone (TQ) or may be reduced by ascorbic acid to regenerate TH. To define the chemistry of this putative two-electron TH redox cycle, we studied the hydrolysis and reduction of 8a-[(2,4-dimethyl-1-nitrilopent-2-yl)dioxyl]tocopherone (1) in acetonitrile/buffer mixtures and in phospholipid liposomes. TQ formation in acetonitrile/buffer mixtures, which was monitored spectrophotometrically, declined with increasing pH and could not be detected above pH 4. The rate of TQ formation from 1 first increased with time and then decreased in a first-order terminal phase. Rearrangement of 8a-hydroxy-?-tocopherone (2) to TQ displayed first-order kinetics identical with the terminal phase for TQ formation from 1. Both rate constants increased with decreasing pH. Hydrolysis of 1 in acetonitrile/H218O yielded [18O]TQ. These observations suggest that 1 loses the 8a-(alkyldioxy) moiety to produce the tocopherone cation (T+), which hydrolyzes to 2, the TQ-forming intermediate. Incubation of either 1 or 2 with ascorbic acid in acetonitrile/buffer yielded TH. Reduction of both 1 and 2 decreased with increasing pH. In phosphatidylcholine liposomes at pH 7, approximately 10% of the T+ generated from 1 was reduced to TH by 5 mM ascorbic acid. The results collectively demonstrate that T+ is the ascorbic acid reducible intermediate in a two-electron TH redox cycle, a process that probably would require biocatalysis to proceed in biological membranes

  16. SYNERGISTIC PROTECTIVE ROLE OF CAFFEINE AND L-ASCORBIC ACID ON LEAD INDUCED PROTEIN CONTENT ALTERATIONS IN VARIOUS TISSUES OF LEMELLIDENS CORRIANUS (LEA

    Directory of Open Access Journals (Sweden)

    Nawale S. P

    2015-02-01

    Full Text Available The present communication deals with individual and synergistic effectiveness of caffeine and L-ascorbic acid in lead induced toxicity in an experimental model, freshwater bivalve, Lamellidens corrianus.The effect on bivalve was studied under nine groups. From each treated and recovery groups, some bivalves were removed and protein contents in selected tissues of bivalves were estimated. The protein level was significantly decreased on exposure to lead while the decrease in presence of caffeine + ascorbic acid was less when exposed simultaneously than when exposed individually. During recovery protein contents recovered and the rate of recovery was faster in caffeine + ascorbic acid exposed bivalves as compared to those recovered individually and in normal water. The probable role of the caffeine (1,3,7- Trimethylexanthine and L-ascorbic acid is discussed in the paper.

  17. Iron binding efficiency of polyphenols: Comparison of effect of ascorbic acid and ethylenediaminetetraacetic acid on catechol and galloyl groups.

    Science.gov (United States)

    Tamilmani, Poonkodi; Pandey, Mohan Chandra

    2016-04-15

    Dietary polyphenols are markedly studied for their antioxidant activity. They also have a negative impact on nutrition whereby they interfere with iron absorption. Common dietary polyphenols include: catechins, flavonols, flavanols, flavones, anthocyanins, proanthocyanidins and phenolic acids. Ascorbic acid (AA) and Ethylenediaminetetraacetic acid (EDTA) are commonly used to counter act this reaction and increase iron bioavailability. This study was aimed at determining the effect of AA and EDTA on the catechol or galloyl iron binding ability of pure phenolics, coffee and tea. Phenolic concentrations of 40, 80, 610, 240, 320, 400, 520 and 900μg/ml were tested against six levels of AA and EDTA. These effects were studied in detail using Multivariate Analysis of Variance (MANOVA) with the hypothesis that there would be one or more mean differences between the ratio of enhancer and the different concentrations of samples tested. AA was found to be more efficient than EDTA in a way that lesser quantity is required for completely overcoming negative iron binding effects of polyphenols and similar samples. PMID:26675868

  18. Determination of uric acid in human urine by eliminating ascorbic acid interference on copper(II)-polydopamine immobilized electrode surface

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • A simple strategy for preparation of ploydopamine-Cu(II) coating on electrode. • The sensor shows the extraordinary selectivity for electrochemical determination of UA. • Modified electrode was characterized in detail. • Practical application was demonstrated in urine samples. - Abstract: The polydopamine (PD) coating was spontaneously formed through simple immersion of glassy carbon (GC) electrode in a dilute aqueous solution of dopamine (DA) at acidic solution (pH = 4.5) in the presence of Cu2+. Copper(II) ions were anchored on surface of GC electrode to prepare a PD-Cu(II) modified electrode. The morphology, composition and electrochemical properties of the PD-Cu(II) films were characterized by scanning electron microscopy, energy-dispersive spectrometry, X-ray photoelectron spectroscopy, powder X-ray diffraction, electrochemical impedance spectroscopy and cyclic voltammetry. This modified electrode shows the extraordinary selectivity for electrochemical determination of uric acid (UA) without interference of high concentration of ascorbic acid (AA). Under coexistence of 5 mM AA, the differential pulse voltammetry peak current of UA give linear response over the range of 0.06–1.68 mM (R2= 0.9934) with detection limit of 24.6 ?M (S/N = 3). Furthermore, the proposed sensor is ideal for the analysis of UA in human urine samples providing satisfactory results

  19. Effects of ascorbic acid and alpha tocopherol supplementation on basal testosterone cortisol ratio in male sprague dawley rats

    International Nuclear Information System (INIS)

    Background: Basal testosterone cortisol ratio is considered very important to maintain homeostasis. Increase in this ratio has various beneficial effects on body. In this study we determined the effects of ascorbic acid and alpha tocopherol supplementation on basal testosterone cortisol ratio in male Sprague Dawley rats. Methods: It was quasi experimental study carried out in department of Physiology, Army Medical College Rawalpindi in collaboration with National Institute of Health, Islamabad during October 2006 to September 2007. Forty male Sprague Dawley rats were divided into four groups with ten rats in each group and above mentioned antioxidants supplementation were given along with standard diet for one month. After this, blood samples were taken and analyzed for serum testosterone and cortisol by ELISA and malondialdehyde levels colorimetrically. Data were analysed on SPSS version 13 and p<0.05 was considered significant. Results: There was no significant rise in testosterone cortisol ratio in rats supplemented with single antioxidant; however rats supplemented with combination of ascorbic acid and alpha tocopherol revealed significant rise in testosterone cortisol ratio with a fall in malondialdehyde levels. Conclusions: Synergistic effects of ascorbic acid and alpha tocopherol resulted in a decline in reactive oxygen species induced lipid peroxidation and rise of testosterone cortisol ratio. (author)

  20. Influence of dried Hokkaido pumpkin and ascorbic acid addition on chemical properties and colour of corn extrudates.

    Science.gov (United States)

    Obradovi?, Valentina; Babi?, Jurislav; Šubari?, Drago; Jozinovi?, Antun; A?kar, ?ur?ica; Klari?, Ilija

    2015-09-15

    The influence of Hokkaido pumpkin powder (PP) addition to corn grits at levels 4%, 6%, and 8% and ascorbic acid (AA) addition at levels 0.5% and 1% was evaluated. Extrusion was done using a single-screw extruder at two temperature regimes: 135/170/170°C (E1) and 100/150/150°C (E2). Mathematical models that describe the influence of additives on the colour of extrudates were determined. Raw extrusion mixtures as well as obtained extrudates were tested for ascorbic acid, polyphenol, proteins, fat, crude fibre, ash and carotenoids content, and antioxidant activity. E1 extrusion regime acted favourably on polyphenols, crude fibre content, and antioxidant activity. It also caused higher fat degradation than E2 extrusion. Xanthophylls (lutein and zeaxanthin) were less sensitive to extrusion than carotenes (?-carotene, 9-cis-?-carotene and 13-cis-?-carotene). Ascorbic acid was more sensitive to higher extrusion temperatures (49-76% degradation). It provided protection to carotenoids and consequently the colour of the extrudates. PMID:25863621

  1. Effects of low temperature on the sugar and ascorbic acid contents of komatsuna (Brassica campestris L.) under limited solar radiation

    International Nuclear Information System (INIS)

    The effects of low temperature on the sugar and ascorbic acid contents of Komatsuna (Brassica campestris L.) plants grown under limited solar radiation in the greenhouse were evaluated. Komatsuna plants were grown in a greenhouse in which the mean air temperature was maintained between 13 degree C and 15 degree C (defined as the 'cool temperature' condition). The solar radiation in the greenhouse fluctuated between 2 and 4 MJ/m2. day-l during the experiment. When Komatsuna plants grew to about 20 cm height, they were transferred to a greenhouse in which the mean air temperature fluctuated between 2 degree C and 3 degree C (defined as the 'cold temperature' or 'cold treatment'). The total sugar contents in leaf blades and in petioles of Komatsuna plants increased rapidly as a function of the cold treatment. The total ascorbic acid content in the leaf blades increased rapidly after the initiation of cold treatment, whereas that content in the petioles increased gradually. On the other hand, the composition of the leaf blades and petioles in the Komatsuna plants did not change when grown continuously in the cool plot. The data show that cold treatment promoted the per unit area production of the total sugar and total ascorbic acid. These results indicate that cold treatment could improve the nutritional qualities of Komatsuna plants, even under limited solar radiation in winter,

  2. Selective complexometric determination of titanium(IV) using sodium potassium tartrate or ascorbic acid as masking agent

    International Nuclear Information System (INIS)

    A simple, rapid and accurate complexometric method is proposed for the determination of titanium(IV) where sodium potassium tartrate or ascorbic acid were used as masking agents. In the presence of diverse metal ions, titanium is first complexed with excess of EDTA and surplus EDTA is then titrated at pH 5-6 with zinc sulfate, xylenol orange being used as indicator. An excess of 5 % aqueous sodium potassium tartrate is then added to displace the complexed EDTA from the Ti-EDTA complex quantitatively, which is titrated with zinc sulfate. Also, ascorbic acid may be used as the releasing agent. The methods work well in the range 1-53 mg of Ti(IV) for sodium potassium tartrate with relative errors ± 0.28 % and standard deviations 0.16 mg. For ascorbic acid the range is 1.00-30.00 mg of Ti(IV) with relative errors of ± 0.40 % and standard deviations of 0.05 mg. (author)

  3. Potentiometric determination of L-ascorbic acid in pharmaceutical samples by FIA using a modified tubular electrode

    Directory of Open Access Journals (Sweden)

    Fernandes Julio Cesar B.

    2000-01-01

    Full Text Available A flow injection system using a tubular electrode based on the redox properties of copper (II ions occluded in EVA membrane was developed for L-ascorbic acid determination. The poly-ethylene-co-vinyl acetate (EVA 40% m/m matrix was doped with copper (II ions and dispersed on the surface of a graphite/epoxy tubular electrode. The electrode showed a super-Nernstian response for L-ascorbic acid concentration between 10-3 and 10-1 mol L-1 with a detection limit of 8.5×10-4 mol L-1, when 0.1 mol L-1 KH2PO4 buffer mixed with 0.1 mol L-1 hydrogen peroxide at pH 5.0 was employed as carrier. The Potentiometric-FIA system allows an analytical frequency of 120 samples per hour with a precision of 3.6%. The results obtained for ascorbic acid determination in pharmaceutical samples, without any previous treatment, were similar to those obtained by the British Pharmacopoeia method.

  4. Effects of ?-tocopherol and ascorbic acid in the severity and management of traumatic brain injury in albino rats

    Directory of Open Access Journals (Sweden)

    Gaafar M Ishaq

    2013-01-01

    Full Text Available Background: Traumatic brain injury (TBI is accompanied by substantial accumulation of biomarkers of oxidative stress and depletion of antioxidants reserve which initiate chain reactions that damage brain cells. The present study investigated the role of ascorbic acid and ?-tocopherol on the severity and management of TBI in rats. Materials and Methods: Wistar rats were subjected to closed head injury using an accelerated impact device. Rats were administered 45 mg/kg and 60 mg/kg body weight of ascorbic acid, ?-tocopherol or a combination of the two vitamins for 2 weeks pre- and post injury. Blood and brain tissue homogenates were analyzed for vitamin C, vitamin E, malondialdehyde, superoxide dismutase, and creatine kinase activities. Results: The results indicated that TBI caused significant (P < 0.05 decreased in vitamins C and E levels in the blood and brain tissue of TBI-untreated rats. The activities of superoxide dismutase in TBI rats were markedly reduced when compared with non traumatized control and showed a tendency to increased following supplementation with vitamins C and E. Supplementation of the vitamins significantly (P < 0.05 reduced malondialdehyde in the treatment groups compared with the TBI-untreated group. Conclusion: The study indicated that pre and post treatment with ascorbic acid and ?-tocopherol reduced oxidative stress induced by brain injury and effectively reduced mortality rate in rats.

  5. Effect of ascorbic acid on fatigue of skeletal muscle fibres in long term cold exposed sprague dawley rats

    International Nuclear Information System (INIS)

    On exposure to prolonged cold temperature, the body responds for effective heat production both by shivering and non-shivering thermo genesis. Cold exposure increases the production of reactive oxygen species which influence the sarcoplasmic reticulum Ca/sup ++/ release from the skeletal muscles and affect their contractile properties. The role of ascorbic acid supplementation on force of contraction during fatigue of cold exposed skeletal muscles was evaluated in this study. Method: Ninety healthy, male Sprague Dawley rats were randomly divided into three groups of control, cold exposed, and cold exposed with ascorbic acid 500 mg/L supplementation mixed in drinking water. Group II and III were given cold exposure by keeping their cages in ice-filled tubs for 1 hr/day for one month. After one month, the extensor digitorum longus muscle was dissected out and force of contraction during fatigue in the skeletal muscle fibres was analysed on a computerised data acquisition system. Results: The cold exposed group showed a significant delay in the force of contraction during fatigue of skeletal muscle fibres compared to control group. Group III showed easy fatigability and a better force of contraction than the cold exposed group. Conclusions: Ascorbic acid increases the force of contraction and decreases resistance to fatigue in the muscles exposed to chronic cold. (author)

  6. L-ascorbic acid determination in pharmaceutical formulations using a biosensor based on carbon paste modified with crude extract of zucchini (Cucurbita pepo

    Directory of Open Access Journals (Sweden)

    Fatibello-Filho Orlando

    2000-01-01

    Full Text Available A biosensor based on carbon paste modified with crude extract of zucchini (Cucurbita pepo as a source of peroxidase is proposed for determining L-ascorbic acid in pharmaceutical formulations. This enzyme in the presence of hydrogen peroxide catalyses the oxidation of hydroquinone to p-quinone whose electrochemical reduction back to hydroquinone was obtained at peak potential of -0.14V. Thus, when L-ascorbic acid is added to the solution, this acid can reduce chemically p-quinone to hydroquinone and/or reduce hydrogen peroxide, decreasing the peak current obtained proportionally to the increase of its concentration. The recovery of L-ascorbic acid from five samples ranged from 98.1 to 102.1% and a rectilinear calibration curve for L-ascorbic acid concentration from 2.0x10-4 to 5.5x10-3 mol L-1 (r=0.9992 was obtained. The detection limit was 2.2x10-5 mol L-1 and relative standard deviation was < 1.3% for a solution containing 4.0x10-3 mol L-1 L-ascorbic acid, 7.0x10-3 mol L-1 hydroquinone and 2.0x10-4 mol L-1 hydrogen peroxide. The results obtained for L-ascorbic acid in pharmaceutical formulations using the proposed biosensor and those obtained using the Pharmacopeia method are in agreement at the 95 % confidence level.

  7. Ascorbic acid and citric flavonoids for broilers under heat stress: effects on performance and meat quality

    Directory of Open Access Journals (Sweden)

    JEM Peña

    2008-06-01

    Full Text Available The aim of this study was to evaluate the effects of increasing doses of ascorbic acid (AA and citric flavonoids (quercetin and rutin on the performance and meat quality characteristics of broilers submitted to cyclic heat stress. Four-hundred one-day-old female Ross 308 were housed in 40 battery cages a in temperature controlled room. Treatments consisted of 0, 250, 500, and 1000 g/ton on of AA + citric flavonoids. Birds were fed ad libitum until 32 day of age. Beginning on day 14 post-hatch until the end of the experiment, in order to simulate cyclic heat stress, the temperature inside the room was increased to 32°C for 5 hours, and decreased until reaching the comfort temperature corresponding to the age of the animals. Birds were slaughtered at 33 days of age, and carcass and commercial cuts yields were determined. Thighs and boneless breast samples were collected and frozen for subsequent analyses of pH, cooking loss, shear force, color, and Thiobarbituric Acid Reactive Substances (TBARS. Significant differences (p <0.05 were found for feed efficiency from 1 to 7 days of age, with the best values for the birds fed 0 and 250 g/ton on of AA + citric flavonoids. At the end of the experiment, there were no differences in other performance variables, carcass and parts yields, pH, shear force, color and TBARS. The meat of the birds supplemented with 250 g/ton on of product presented the lowest cooking loss.

  8. EVALUATION OF ANTIPEROXIDATIVE POTENTIAL OF ASCORBIC ACID ON BUSULFAN-INDUCED LIPID PEROXIDATION USING 4-HYDROXY-2-NONENAL AND NITRIC OXIDE AS MODEL MARKERS

    OpenAIRE

    Supratim Ray

    2012-01-01

    The study was designed with an aim to evaluate the antiperoxidative potential of ascorbic acid on busulfan-induced lipid peroxidation. The study was performed in vitro using goat liver as lipid source. This evaluation was done by measuring the 4-hydroxy-2-nonenal (4-HNE) and nitric oxide (NO) content of liver tissue homogenates as markers of lipid peroxidation. The study reveals the lipid peroxidation induction capacity of busulfan and the antiperoxidative potential of ascorbic acid on busulf...

  9. Pro-oxidative vs antioxidative properties of ascorbic acid in chromium(VI)-induced damage: an in vivo and in vitro approach.

    Science.gov (United States)

    Poljsak, B; Gazdag, Z; Jenko-Brinovec, S; Fujs, S; Pesti, M; Bélagyi, J; Plesnicar, S; Raspor, P

    2005-01-01

    The effect of antioxidant ascorbic acid (vitamin C) pretreatment on chromium(VI)-induced damage was investigated using the yeast Saccharomyces cerevisiae as a model organism. The objective of this study was to pretreat yeast cells with the antioxidant ascorbic acid in an effort to increase cell tolerance against reactive chromium intermediates and reactive oxygen species formed during chromium(VI) reduction. Intracellular oxidation was estimated using the fluorescence indicators dihidro-2,7-dichlorofluorescein, dihydroethidium and dihydrorhodamine 123. The role of ascorbic acid pretreatment on chromium(VI) toxicity was determined by measuring mitotic gene conversion, reverse mutations, 8-OHdG, hydroxyl radical, superoxide anion and chromium(V) formation. The chromium content in the biomass was determined by flame atomic absorption spectrometry. In the absence of chromium, ascorbic acid effectively protected the cells against endogenous reactive oxygen species formed during normal cellular metabolism. In vitro measurements employing EPR and the results of supercoiled DNA cleavage revealed that the pro-oxidative action of ascorbic acid during Cr(VI) reduction was concentration-dependent and that harmful hydroxyl radical and Cr(V) had formed following Cr(VI) reduction. However, the in vivo results highlighted the important role of increased cytosol reduction capacity related to modification of Cr(V) formation, increased chromium accumulation, better scavenging ability of superoxide anions and hydrogen peroxide, and consequently decreased cytotoxicity and genotoxicity in ascorbic acid pretreated cells. Ascorbic acid influenced Cr(VI) toxicity both as a reducing agent, by decreasing Cr(V) persistence, and as an antioxidant, by decreasing intracellular superoxide anion and hydrogen peroxide formation and by quenching free radicals formed during Cr(VI) to Cr(III) reduction. Increased 8-OHdG and decreased reduced glutathione in ascorbic acid-treated cells might induce an endogenous antioxidant defense system and thus increase cell tolerance against subsequent Cr-induced stress. PMID:16092082

  10. Report of the Pilot Study Done for the Proposed Investigation on the Possible Synergic Effect between High-Dose Ascorbic Acid Application and Oncothermia Treatment

    OpenAIRE

    Csaba Kovago; Nora Meggyeshazi; Gabor Andocs; Andras Szasz

    2013-01-01

    According to recent investigations, the parenteral application of ascorbic acid (vitamin C) at high doses has significant antitumor activity in in vitro assays. The goal of our experiment was to determine the possible potentiating effect of application of high dose pH-neutralized ascorbic acid to the normal oncothermia treatment method. The NMRI mice were inoculated with C26 murine colon carcinoma cell line subcutaneously at both of their femoral regions and were kept till the tumors reached ...

  11. Ascorbic acid is a key participant during the interactions between chloroplasts and mitochondria to optimize photosynthesis and protect against photoinhibition

    Indian Academy of Sciences (India)

    Saikrishna Talla; Khateef Riazunnisa; Lolla Padmavathi; Pidakala Rajsheel; Agepati S Raghavendra

    2011-03-01

    The possible role of L-ascorbate (AsA) as a biochemical signal during the interactions between photosynthesis and respiration was examined in leaf discs of Arabidopsis thaliana. AsA content was either decreased as in AsA-deficient vtc1 mutants or increased by treatment with L-galactono-1, 4-lactone (L-GalL, a precursor of AsA; EC 1.3.2.3). In mutants, photosynthesis was extremely sensitive to both antimycin A (inhibitor of the cytochrome oxidase pathway [COX pathway]) and salicylhydroxamic acid (SHAM, inhibitor of the alternative pathway [AOX pathway]), particularly at high light conditions. Mitochondrial inhibitors lowered the ratio of reduced AsA to total AsA, at high light, indicating oxidative stress in leaf discs. Elevation of AsA by L-GalL decreased the sensitivity of photosynthesis at high light to antimycin A or SHAM, sustained photosynthesis at supraoptimal light and relieved the extent of photoinhibition. High ratios of reduced AsA to total AsA in L-GalL-treated leaf discs suggests that L-GalL lowers oxidative stress. The protection by L-GalL of photosynthesis against the mitochondrial inhibitors and photoinhibition was quite pronounced in vtc1 mutants. Our results suggest that the levels and redox state of AsA modify the pattern of modulation of photosynthesis by mitochondrial metabolism. The extent of the AOX pathway as a percentage of the total respiration in Arabidopsis mesophyll protoplasts was much higher in vtc1 than in wild type. We suggest that the role of AsA becomes pronounced at high light and/or when the AOX pathway is inhibited. While acknowledging the importance of the COX pathway, we hypothesize that AsA and the AOX pathway may complement each other to protect photosynthesis against photoinhibition.

  12. Ascorbic acid improves brachial artery vasodilation during progressive handgrip exercise in the elderly through a nitric oxide-mediated mechanism.

    Science.gov (United States)

    Trinity, Joel D; Wray, D Walter; Witman, Melissa A H; Layec, Gwenael; Barrett-O'Keefe, Zachary; Ives, Stephen J; Conklin, Jamie D; Reese, Van; Zhao, Jia; Richardson, Russell S

    2016-03-15

    The proposed mechanistic link between the age-related attenuation in vascular function and free radicals is an attractive hypothesis; however, direct evidence of free radical attenuation and a concomitant improvement in vascular function in the elderly is lacking. Therefore, this study sought to test the hypothesis that ascorbic acid (AA), administered intra-arterially during progressive handgrip exercise, improves brachial artery (BA) vasodilation in a nitric oxide (NO)-dependent manner, by mitigating free radical production. BA vasodilation (Doppler ultrasound) and free radical outflow [electron paramagnetic resonance (EPR) spectroscopy] were measured in seven healthy older adults (69 ± 2 yr) during handgrip exercise at 3, 6, 9, and 12 kg (∼13-52% of maximal voluntary contraction) during the control condition and nitric oxide synthase (NOS) inhibition via N(G)-monomethyl-l-arginine (l-NMMA), AA, and coinfusion of l-NMMA + AA. Baseline BA diameter was not altered by any of the treatments, while l-NMMA and l-NMMA + AA diminished baseline BA blood flow and shear rate. AA improved BA dilation compared with control at 9 kg (control: 6.5 ± 2.2%, AA: 10.9 ± 2.5%, P = 0.01) and 12 kg (control: 9.5 ± 2.7%, AA: 15.9 ± 3.7%, P exercise intensity but, interestingly, was not attenuated by AA. Collectively, these results indicate that AA improves BA vasodilation in the elderly during handgrip exercise through an NO-dependent mechanism; however, this improvement appears not to be the direct consequence of attenuated free radical outflow from the forearm. PMID:26801312

  13. Effect of the Ascorbic Acid, Pyridoxine and Hydrogen Peroxide Treatments on Germination, Catalase Activity, Protein and Malondialdehyde Content of Three Oil Seeds

    Directory of Open Access Journals (Sweden)

    Aria DOLATABADIAN

    2008-08-01

    Full Text Available Oil seed production has an important role in human nutrition and industry. Success in oil plant cultivation is related to seed production with high viability and rapid germination, because these seeds rapidly loose their viability by fats oxidation. Thus, in this work we studied the effects of ascorbic acid, pyridoxine and hydrogen peroxide solutions on germination quantitative traits, catalase activity, protein and malondialdehyde content of three old oil seeds (sunflower, rape seed and safflower. The results showed that ascorbic acid and pyridoxine stimulated significantly the sunflower and rape seed germination. These vitamins, however, didn't have any effect on safflower germination. Hydrogen peroxide strongly increased safflower germination. Ascorbic acid and pyridoxine decreased catalase activity in sunflower and rape seed, whereas hydrogen peroxide increased it. Ascorbic acid and pyridoxine prevented protein degradation and lipid peroxidation in germinated seeds. Consequently, we understand that ascorbic acid and pyridoxine can increase sunflower and rape seed germination and stimulate rate of growth. Also safflower germination increased due to germination inhibitor oxidation by hydrogen peroxide. In conclusion, this report shows that oil seeds treated with ascorbic acid, pyridoxine and hydrogen peroxide remarkably increase the capacity of germination. We suggest that treatments with such substances can improve the old oil seed germination during storage.

  14. Addition of l-ascorbic acid to culture and vitrification media of IVF porcine blastocysts improves survival and reduces HSPA1A levels of vitrified embryos.

    Science.gov (United States)

    Castillo-Martín, Miriam; Yeste, Marc; Soler, Albert; Morató, Roser; Bonet, Sergi

    2014-04-17

    The aim of the present study was to determine the effect of l-ascorbic acid on embryo quality and gene expression of porcine blastocysts after supplementations of in vitro culture medium and/or vitrification-warming media. Embryo quality, in terms of total cell number (TCN), DNA fragmentation and peroxide levels, together with the relative transcript abundance of BCL-2 associated X protein (BAX), BCL2-like 1 (BCL2L1), POU class 5 homeobox 1 (POU5F1) and heat shock protein 70 (HSPA1A), was analysed. In Experiment 1, gene expression and embryo quality of fresh blastocysts were evaluated after culture with or without l-ascorbic acid; no significant differences were observed between the groups. In Experiment 2, blastocysts cultured with or without l-ascorbic acid were vitrified using two different vitrification solutions, supplemented or not with l-ascorbic acid. Supplementation of culture and vitrification media significantly enhanced survival rates and reduced peroxide levels. No significant differences in TCN, DNA fragmentation and BAX, BCL2L1 and POU5F1 expression were found in vitrified blastocysts among experimental groups. Vitrification procedures increase HSPA1A transcript abundance, but this increase was significantly lower in embryos cultured and/or vitrified with l-ascorbic acid. Thus, supplementing culture and/or vitrification media with l-ascorbic acid enhances survival rates of porcine blastocysts, suggesting a relationship with HSPA1A expression. PMID:25322209

  15. Effect of Ascorbic Acid (Vitamin C Leaf Feeding on Antioxidant Enzymes Activity, Proline Accumulation and Lipid Peroxidation of Canola (Brassica napus L. under Salt Stress Condition

    Directory of Open Access Journals (Sweden)

    A Modares Sanavi

    2009-04-01

    Full Text Available In order to study the effects of salt stress and leaf feeding by ascorbic acid on antioxidant enzyme activity, proline accumulation and lipid peroxidation on leaves and roots of Brassica napus L. cvs. Okapi, an experiment was conducted as a factorial in a completely random design with three replications. Plants were exposed to salt stresses by NaCl solution (200 mM and foliar were treated by ascorbic acid solution (25mM. Catalase, Superoxide dismutase and peroxidase activity were assayed in shoot and root. Also, malondialdehyde content and proline and chlorophyll in leaves were determined. The results showed that the activity of all antioxidant enzymes (except for SOD in roots were increased significantly in plants under salt stress, and ascorbic acid application, as a antioxidant decreased their activity in leaves, but in roots it was not effective. Total protein content in leaves and roots decreased significantly under salinity condition. Ascorbic acid treatment increased total protein content under salt stress in both roots and shoots. Measurement of malondialdehyde content in leaves and roots showed that lipid peroxidation was increased by active oxygen species due to salt stress, and ascorbic acid reduced lipid peroxidation only in leaves. Chlorophyll content was also decreased by salinity compared to control. According to the result of present study, ascorbic acid application decreases deleterious effect of salinity.

  16. Scientific Opinion on the safety and efficacy of vitamin C (ascorbic acid, sodium ascorbate, calcium ascorbate, ascorbyl palmitate, sodium calcium ascorbyl phosphate and sodium ascorbyl phosphate as a feed additive for all animal species based on a dossier submitted by DSM Nutritional Products Ltd

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP

    2013-02-01

    Full Text Available Vitamin C is essential for primates, guinea pigs and fish. Vitamin C, in the form of ascorbic acid and its calcium and sodium salts, ascorbyl palmitate, sodium calcium ascorbyl phosphate and sodium ascorbyl phosphate, is safe for all animal species. Setting a maximum content in feed and water for drinking is not considered necessary. Data on the vitamin C consumption of consumers are based on the levels of vitamin C in foodstuffs, including food of animal origin, produced in accordance with current EU legislation on the supplementation of feed with vitamin C. The exposure is far below the guidance level. Any potential contribution of the use of vitamin C in feed is therefore already considered in the above data. Consequently, the use of vitamin C in animal nutrition is not of concern for consumer safety. In the absence of inhalation toxicity studies it would be prudent to assume that inhalation of dust from the additives presents a health hazard to workers. Sodium calcium ascorbyl phosphate is not an irritant to skin and eyes and is unlikely to be a skin sensitiser. This conclusion is extrapolated to sodium ascorbyl phosphate. In the absence of data, ascorbic acid, sodium ascorbate, calcium ascorbate and ascorbyl palmitate should be considered as irritant to skin and eyes and as dermal sensitisers. The supplementation of feed with vitamin C does not pose a risk to the environment. Ascorbic acid, sodium calcium ascorbyl phosphate and sodium ascorbyl phosphate are regarded as effective sources of vitamin C when added to feed or water for drinking. Since ascorbic acid, sodium ascorbate, calcium ascorbate and ascorbyl palmitate are authorised for use as antioxidants in food and their function in feed is essentially the same as that in food, no further demonstration of efficacy is considered necessary.

  17. Amperometric microsensor for direct probing of ascorbic acid in human gastric juice

    Energy Technology Data Exchange (ETDEWEB)

    Hutton, Emily A.; Pauliukaite, Rasa; Hocevar, Samo B. [Analytical Chemistry Laboratory, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia); Ogorevc, Bozidar, E-mail: bogorevc@ki.s [Analytical Chemistry Laboratory, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia); Smyth, Malcolm R. [National Centre for Sensor Research, School of Chemical Sciences, Dublin City University, Dublin 9 (Ireland)

    2010-09-30

    This article reports on a novel microsensor for amperometric measurement of ascorbic acid (AA) under acidic conditions (pH 2) based on a carbon fiber microelectrode (CFME) modified with nickel oxide and ruthenium hexacyanoferrate (NiO-RuHCF). This sensing layer was deposited electrochemically in a two-step procedure involving an initial galvanostatic NiO deposition followed by a potentiodynamic RuHCF deposition from solutions containing the precursor salts. Several important parameters were examined to characterize and optimize the NiO-RuHCF sensing layer with respect to its current response to AA by using cyclic voltammetry, and scanning electron microscopy-energy dispersive X-ray spectroscopy methods. With the NiO-RuHCF coated CFME, the AA oxidation potential under acidic conditions was shifted to a less positive value for about 0.2 V (E{sub p} of ca. 0.23 V vs. Ag/AgCl) as compared to a bare CFME, which greatly improves the electrochemical selectivity. Using the hydrodynamic amperometry mode, the current vs. AA concentration in 0.01 M HCl, at a selected operating potential of 0.30 V, was found to be linear over a wide range of 10-1610 {mu}M (n = 22, r = 0.999) with a calculated limit of detection of 1.0 {mu}M. The measurement repeatability was satisfactory with a relative standard deviation (r.s.d.) ranging from 4% to 5% (n = 6), depending on the AA concentration, and with a sensor-to-sensor reproducibility (r.s.d.) of 6.9% at 100 {mu}M AA. The long-term reproducibility, using the same microsensor for 112 consecutive measurements of 20 {mu}M AA over 11 h of periodic probing sets over 4 days, was 16.1% r.s.d., thus showing very good stability at low AA levels and suitability for use over a prolonged period of time. Moreover, using the proposed microsensor, additionally coated with a protective cellulose acetate membrane, the calibration plot obtained in the extremely complex matrix of real undiluted gastric juice was linear from 10 to 520 {mu}M (n = 14, r = 0.998). These results demonstrated the unique featuring of the proposed NiO-RuHCF microsensor under acidic conditions with enhanced sensitivity and stability and proved its promising potentiality for direct amperometric probing of AA at physiological levels in real gastric juice environments.

  18. The effect of long term administration of ascorbic acid on the learning and memory deficits induced by diabetes in rat

    Directory of Open Access Journals (Sweden)

    Parisa Hasanein

    2010-04-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Ascorbic acid improves cognitive impairments in several experimental models. Diabetes causes learning and memory deficits. In this study we hypothesized that chronic treatment with ascorbic acid (100mg/kg, p.o would affect on the passive avoidance learning (PAL and memory in control and streptozocin-induced diabetic rats."n"nMethods: Diabetes was induced by a single i.p. injection of STZ (60mg/kg. The rats were considered diabetic if plasma glucose levels exceeded 250mg/dl on three days after STZ injection. Treatment was begun at the onset of hyperglycemia. PAL was assessed 30 days later. Retention test was done 24 h after training. At the end, animals were weighted and blood samples were drawn for plasma glucose measurement."n"nResults: Diabetes caused impairment in acquisition and retrieval processes of PAL and memory in rats. Ascorbic acid treatment improved learning and memory in control rats and reversed learning and memory deficits in diabetic rats. Ascorbic acid administration also improved the body weight loss and hyperglycemia of diabetics. Hypoglycemic and antioxidant properties of the vitamin may be involved in the memory improving effects of such treatment."n"nConclusion: These results show that ascorbic acid administration to rats for 30 days from onset of diabetes alleviated the negative influence of diabetes on learning and memory. Comparing with other nootropic drugs, vitamins have fewer side effects. Therefore, this regimen may provide a new potential alternative for prevention of the impaired cognitive functions associated with diabetes after confirming by clinical trials.

  19. Ascorbic acid enhances destruction of Escherichia coli O157:H7 during home-type drying of apple slices.

    Science.gov (United States)

    Burnham, J A; Kendall, P A; Sofos, J N

    2001-08-01

    Destruction of Escherichia coli O157:H7 was evaluated on inoculated apple slices dehydrated at two temperatures with and without application of predrying treatments. Half-ring slices (0.6 cm thick) of peeled and cored Gala apples were inoculated by immersion for 30 min in a four-strain composite inoculum of E. coli O157:H7. The inoculated slices (8.7 to 9.4 log CFU/g) either received no predrying treatment (control), were soaked for 15 min in a 3.4% ascorbic acid solution, or were steam blanched for 3 min at 88 degrees C immediately prior to drying at 57.2 or 62.8 degrees C for up to 6 h. Samples were plated on tryptic soy (TSA) and sorbitol MacConkey (SMAC) agar media for direct enumeration of surviving bacterial populations. Steam blanching changed initial inoculation levels by +0.3 to -0.7 log CFU/g, while immersion in the ascorbic acid solution reduced the inoculation levels by 1.4 to 1.6 log CFU/g. Dehydration of control samples for 6 h reduced mean bacterial populations by 2.9 log CFU/g (TSA or SMAC) at 57.2 degrees C and by 3.3 (SMAC) and 3.5 (TSA) log CFU/g at 62.8 degrees C. Mean decreases from initial inoculum levels for steam-blanched slices after 6 h of drying were 2.1 (SMAC) and 2.0 (TSA) log CFU/g at 57.2 degrees C, and 3.6 (TSA or SMAC) log CFU/g at 62.8 degrees C. In contrast, initial bacterial populations on ascorbic acid-pretreated apple slices declined by 5.0 (SMAC) and 5.1 (TSA) log CFU/g after 3 h of dehydration at 57.2 degrees C, and by 7.3 (SMAC) and 6.9 (TSA) log CFU/g after 3 h at 62.8 degrees C. Reductions on slices treated with ascorbic acid were in the range of 8.0 to 8.3 log CFU/g after 6 h of drying, irrespective of drying temperature or agar medium used. The results of immersing apple slices in a 3.4% ascorbic acid solution for 15 min prior to drying indicate that a predrying treatment enhances the destruction of E. coli O157:H7 on home-dried apple products. PMID:11510669

  20. Graphitic carbon nitride nanosheets doped graphene oxide for electrochemical simultaneous determination of ascorbic acid, dopamine and uric acid

    International Nuclear Information System (INIS)

    Graphical abstract: Schematic drawing of electrochemical oxidize AA, DA and UA on graphitic carbon nitride nanosheets-graphene oxide composite modified electrode. - Highlights: • Synthesize g-C3N4, GO and CNNS-GO composite. • CNNS-GO composite was the first time for simultaneous determination of AA, DA and UA. • CNNS-GO/GCE displays fantastic selectivity and sensitivity for AA, DA and UA. • CNNS-GO/GCE was applied to detect real sample with satisfactory results. - Abstract: Graphitic carbon nitride nanosheets with a graphite-like structure have strong covalent bonds between carbon and nitride atoms, and nitrogen atoms in the carbon architecture can accelerate the electron transfer and enhance electrical properties effectually. The graphitic carbon nitride nanosheets-graphene oxide composite was synthesized. And the electrochemical performance of the composite was investigated by cyclic voltammetry and differential pulse voltammetry ulteriorly. Due to the synergistic effects of layer-by-layer structures by ?-? stacking or charge-transfer interactions, graphitic carbon nitride nanosheets-graphene oxide composite can improved conductivity, electro-catalytic and selective oxidation performance. The proposed graphitic carbon nitride nanosheets-graphene oxide composite modified electrode was employed for simultaneous determination of ascorbic acid, dopamine and uric acid in their mixture solution, it exhibited distinguished sensitivity, wide linear range and low detection limit. Moreover, the modified electrode was applied to detect urine and dopamine injection sample, and then the samples were spiked with certain concentration of three substances with satisfactory recovery results

  1. Noncovalent nanohybrid of cobalt tetraphenylporphyrin with graphene for simultaneous detection of ascorbic acid, dopamine, and uric acid

    International Nuclear Information System (INIS)

    Highlights: •A noncovalent nanohybrid of cobalt tetraphenylporphyrin with chemically reduced graphene oxide was prepared. •The nanohybrid was characterized by UV–vis spectroscopy, Raman spectroscopy, and atomic force microscopy. •The nanohybrid can be applied to simultaneously detect AA, DA and UA with high sensitivity and low detection limit. -- Abstract: A noncovalent nanohybrid of cobalt tetraphenylporphyrin (CoTPP) with chemically reduced graphene oxide (CRGO) was prepared through ?–? stacking interaction between CRGO and CoTPP. The hybrid (CoTPP-CRGO) was characterized by UV–vis spectroscopy, Raman spectroscopy, and atomic force microscopy. The electrochemical behaviors of ascorbic acid (AA), dopamine (DA), and uric acid (UA) at CoTPP-CRGO modified glass carbon electrode (CoTPP-CRGO/GCE) were studied by cyclic voltammetry (CV). Three well-resolved oxidation peaks were obtained. The peak potential separations were 225 and 140 mV for AA and DA, DA and UA respectively. Owing to the synergistic effect of CoTPP and CRGO, CoTPP-CRGO showed faster electron transfer and stronger electrocatalysis than CoTPP, CRGO or their mixture. The proposed modified electrode exhibited linear responses to AA, DA and UA in the ranges of 5.0–200.0 ?M, 0.1–12.0 ?M, 0.5–40 ?M, respectively. The detection limits were 1.2, 0.03, and 0.15 ?M, respectively. It was also applied to detect real samples with a satisfactory result

  2. Determination of dopamine in presence of ascorbic acid and uric acid using poly (Spands Reagent) modified carbon paste electrode.

    Science.gov (United States)

    Veera Manohara Reddy, Y; Prabhakara Rao, V; Vijaya Bhaskar Reddy, A; Lavanya, M; Venu, M; Lavanya, M; Madhavi, G

    2015-12-01

    In this paper, we have fabricated a modified carbon paste electrode (CPE) by electropolymerisation of spands reagent (SR) onto surface of CPE using cyclic voltammetry (CV). The developed electrode was abbreviated as poly(SR)/CPE and the surface morphology of the modified electrode was studied by using scanning electron microscopy (SEM). The developed electrode showed higher electrocatalytic properties towards the detection of dopamine (DA) in 0.1M phosphate buffer solution (PBS) at pH7.0. The effect of pH, scan rate, accumulation time and concentration of dopamine was studied at poly(SR)/CPE. The poly(SR)/CPE was successfully used as a sensor for the selective determination of DA in presence of ascorbic acid (AA) and uric acid (UA) without any interference. The poly(SR)/CPE showed a good detection limit of 0.7?M over the linear dynamic range of 1.6?M to 16?M, which is extremely lower than the reported methods. The prepared poly(SR)/CPE exhibited good stability, high sensitivity, better reproducibility, low detection limit towards the determination of DA. The developed method was also applied for the determination of DA in real samples. PMID:26354279

  3. Avaliação da interferência do ácido ascórbico na detecção da glicosúria Evaluation of ascorbic acid interference in the detection of glycosuria

    Directory of Open Access Journals (Sweden)

    Jaime Murilo Fernandes Costa

    2012-02-01

    Full Text Available INTRODUÇÃO: O ácido ascórbico (vitamina C é comumente ingerido como suplemento vitamínico. É uma vitamina hidrossolúvel, excretada pela urina e pode interferir nos ensaios laboratoriais, como nas reações de oxirredução para detecção da glicosúria. OBJETIVO: Este trabalho tem como objetivo avaliar a interferência do ácido ascórbico na detecção de glicosúria pelo método de química seca por meio do uso de tiras reagentes. MATERIAIS E MÉTODOS: Amostras de urina foram avaliadas no analisador da marca Clinitek Atlas (Siemens Healthcare Diagnostics Inc., EUA. Foram selecionadas quatro amostras de urina com diferentes concentrações de glicose: 100 mg/dl, 250 mg/dl, 500 mg/dl e 1.000 mg/dl. Para cada concentração de glicose foram criadas cinco alíquotas, adicionando-se uma solução de ácido ascórbico 200 mg/dl, suficiente para obter uma concentração final de ácido ascórbico de 20 mg/dl no primeiro tubo, de 50 mg/dl no segundo tubo, de 270 mg/dl no terceiro tubo, de 1.000 mg/dl no quarto tubo e de 2.000 mg/dl no quinto tubo. Após essa adição, as amostras foram novamente avaliadas no analisador Clinitek Atlas. RESULTADOS: Nas amostras com concentração de 20 mg/dl de ácido, não se evidenciou interferência. Nas concentrações iguais e acima de 50 mg/dl, a interferência do ácido ascórbico se fez presente, sendo que o fato foi caracterizado pelos resultados falso negativos para detecção da glicose urinária. CONCLUSÃO: Os resultados demonstraram a interferência do ácido ascórbico no método da química seca (tiras reagentes, subestimando o nível de glicose urinária.INTRODUCTION: Ascorbic acid (vitamin C is commonly used as a vitamin supplement. It is a water soluble vitamin, which is excreted through urine and may interfere in laboratory tests as well as redox reactions for urinary glucose detection. OBJECTIVE: This study aims to assess ascorbic acid interference in glycosuria detection by dry chemistry method (reagent strips. MATERIAL AND METHODS: Urine samples were evaluated by using Clinitek Atlas chemistry analyzer (Siemens Healthcare Diagnostics Inc., USA. Four urine samples with different glucose concentrations were selected: 100 mg/dl, 250 mg/dl, 500 mg/dl and > 1,000 mg/dl. 5 aliquots were created for each glucose concentration and a solution of ascorbic acid 200 mg/dl was added, sufficient to obtain a final ascorbic acid concentration of 20 mg/dl in the first tube, 50 mg/dl in the second tube, 270 mg/dl in the third tube, 1,000 mg/dl the fourth tube, and 2,000 mg/dl in the fifth tube. After the addition of ascorbic acid, the samples were reassessed by using Clinitek Atlas chemistry analyzer. RESULTS: There was no interference at concentrations of 20 mg/dl. However, there was ascorbic acid interference at concentrations higher than or equal to 50 mg/dl, which was characterized by false-negative results for urinary glucose detection. CONCLUSION: The results corroborated the interference of ascorbic acid in dry chemistry method (reagent strips inasmuch as it underestimates urinary glucose levels.

  4. Application of ascorbic acid 2-glucoside as a solubilizing agent for clarithromycin: solubilization and nanoparticle formation.

    Science.gov (United States)

    Inoue, Yutaka; Yoshimura, Sachie; Tozuka, Yuichi; Moribe, Kunikazu; Kumamoto, Takuya; Ishikawa, Tsutomu; Yamamoto, Keiji

    2007-02-22

    Clarithromycin (CAM) was co-ground with l-ascorbic acid 2-glucoside (AA-2G), a newly developed food additive, to improve the solubility characteristics. The complete solubilizing effect of AA-2G was observed for the ground mixture with 1:1 molar ratio. When ground mixtures of CAM and AA-2G (2:1) were dispersed into water, not only the solubilization of CAM was observed but also nanoparticle formation with a mean particle diameter of 280 nm. The CAM particles obtained in this manner were stable in suspension for at least 7 days. Zeta potential analysis showed that positive charges on the particle surface may be contributing to the stability of the suspension. 1H NMR spectrum of CAM dissolved in a phosphate buffer (pH 5.5) showed a signal derived from the N,N-dimethylamino group at 2.73 ppm, while that of an equimolar ground mixture of CAM with AA-2G in D2O (pH 5.5) showed clearly two signals at 2.65 and 2.77 ppm derived from the splitting of the two methyl groups. The 13C NMR spectrum of the equimolar ground mixture dissolved in D2O exhibited two signals derived from N,N-dimethyl carbons of desosamine group at 37.2 and 42.3 ppm, whereas unprocessed CAM showed no resonance signal arising from those carbons. Moreover, the carbon resonance at 163 and 173 ppm arising from the ketone group in the CAM lactone ring shifted downfield to 177 and 180 ppm after the co-grinding with AA-2G. The formation of nanoparticles was only observed when CAM was co-ground with AA-2G in the molar ratio of 2:1, which might be attributable to a grinding-induced interaction in the solid-state via the ketone group in lactone ring of CAM. PMID:17055675

  5. Modulatory effect of ascorbic acid on physiological responses of transported ostrich chicks

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    Minka N. Salka

    2012-02-01

    Full Text Available The aims of this study were to determine the modulating role of ascorbic acid (AA on rectal temperature (RT, heterophil to lymphocyte (H to L ratio and aberrant behaviours of ostrich chicks transported by road for 4 h during hot-dry conditions. Twenty ostrich chicks aged 2.5 months, of both sexes and belonging to the Red Neck breed, served as subjects of the study. The chicks were assigned randomly to AA-treated and control groups, consisting of 10 chicks each. The AA-treated group was administered orally with 100 mg/kg body weight of AA dissolved in 5 mL of sterile water 30 min before transportation, whilst the control group was given the equivalent of sterile water only. The thermal load (TL experienced in the vehicle during transportation fluctuated between 31 °C and 89 °C, as calculated from the ambient temperature and relative humidity. Transportation induced hyperthermia, lymphopenia, heterophilia and aberrant behaviours of pecking, wing fluffing and panting, which were ameliorated by AA administration. The relationships between the TL, journey duration and physiological variables of RT, H to L ratio and aberrant behaviours recorded during transportation were significantly and positively correlated in the control group. In AA-treated group the relationships were not significantly correlated. In conclusion, the results showed for the first time that AA ameliorated the adverse effects of stress caused by road transportation on the aberrant behaviours, RT and H to L ratio of ostrich chicks during the hot-dry season.

  6. Ratiometric electrochemical sensor for effective and reliable detection of ascorbic acid in living brains.

    Science.gov (United States)

    Cheng, Hanjun; Wang, Xiaoyu; Wei, Hui

    2015-09-01

    The in vivo detection of ascorbic acid (AA), one of the physiologically important cerebral neurochemicals, is critical to probe and understand brain functions. Electrochemical sensors are convenient for AA detection. However, conventional electrochemical sensors usually suffer from several challenges, such as sluggish electron transfer kinetics for AA oxidation and poor reproducibility. To address these challenges, here we report ratiometric electrochemical sensors for effective and reliable detection of AA in living brains. The sensors were constructed by immobilizing preassembled thionine/Ketjen black (KB) nanocomposites onto glassy carbon (GC) electrodes or carbon fiber microelectrodes (CFMEs). The KB in the rationally functionalized nanocomposites efficiently facilitated AA oxidation at a relatively negative potential (?-0.14 V) without particular physical or chemical pretreatment, forming the basis of selective measurement of AA. With a well-defined and reversible pair of redox wave at -0.22 V, the assembled thionine acted as an internal reference to substantially alleviate the lab-to-lab, person-to-person, and electrode-to-electrode variations. The in vitro experiments demonstrated that the sensors exhibited extremely high reproducibility and stability toward selective measurement of AA. More, with operational simplicity and robustness in analytical performance, the designed sensors were successfully applied to in vivo effectively, selectively, and reliably monitor the dynamic change of cerebral AA associated with pathological processes (i.e., salicylate-induced tinnitus as the model) in living rats' brains. This study not only offers a new strategy for construction of ratiometric electrochemical sensors but also opens a new way for selective and reliable detection of neurochemicals for probing brain functions. PMID:26244714

  7. WO3 nanoparticles based direct electrochemical dopamine sensor in the presence of ascorbic acid

    International Nuclear Information System (INIS)

    Graphical abstract: Display Omitted -- Highlights: •This paper presents very simple and mediator-free dopamine detection using ovoid shaped WO3 NPs for the first time. •The fabricated sensor exhibits wide linear range (0.1–600 μmol L−1) with the lowest detection limit of 24 nmol L−1. •This novel sensor is highly selective towards the determination of DA even in the presence of 100 fold excess of AA. -- Abstract: Tungsten trioxide (WO3) nanoparticles with monoclinic (γ) and orthorhombic (β) structures were synthesized by a simple microwave irradiation method and characterized using powder X-ray diffraction (XRD), electron energy loss spectroscopy (EELS), Raman spectroscopy, field emission scanning electron microscopy (FESEM), UV–vis absorption and photoluminescence (PL) spectroscopy studies. The γ-WO3 nanoparticles modified glassy carbon electrode (GCE) showed an excellent electrocatalytic activity towards the oxidation of dopamine (DA) in the presence of ascorbic acid (AA) at pH 7.0. Electrochemical kinetic parameters of γ-WO3/GCE such as electroactive area A (0.045 cm2), electron transfer coefficient α (0.71) and electron transfer rate constant ks (1.121 s−1) were calculated and compared with that of β-WO3/GCE. Differential pulse voltammetry (DPV) studies of the γ-WO3 modified GCE exhibited a linear response over a wide concentration range of 0.1 μmol L−1–600 μmol L−1 of DA with the lowest detection limit of 24 nmol L−1. The fabricated dopamine sensor showed an excellent anti-interference ability against electroactive species and metal ions with good stability and reproducibility. Finally, the developed sensor was applied to determine DA concentration in dopamine hydrochloride injection which indicates that this electrode can be effectively used for real sample analysis

  8. Novel Spectrophotometric Methods for Determination of Salicylamide and Ascorbic acid in their binary mixture

    International Nuclear Information System (INIS)

    Simple, selective and precise four spectrophotometric methods were developed and validated for quantitative determination of Salicylamide (SAD) and Ascorbic acid (ASC, Vitamin C) in their binary mixture. Method A is Area under curve spectrophotometry, in which the area under curve in the wavelength ranges 225-245 nm and 265-285 nm were selected for determination of SAD and ASC. Method B is based on dual wavelength spectrophotometry, where ASC can be determined by difference in absorbance at 249.8 and 285.8 nm. On the same way; SAD is measured by difference in absorbance at 240.4 and 286.4 nm. Method C utilizes isoabsorptive point spectrophotometry where total concentration of SAD and ASC was calculated at their isoabsorptive points at 246.4 and 287 nm, while SAD concentration alone can be determined by first derivative spectrophotometry (1D) at 315.4 nm, then ASC concentration can be determined by subtraction. Method D is ratio subtraction spectrophotometry, where ASC can be determined by dividing the spectrum of the mixture by the spectrum of the SAD (as a divisor) followed by subtracting the constant absorbance value of the plateau region, then finally multiplying the obtained spectrum by the spectrum of the divisor. The developed methods have been successfully applied for determination of the studied drugs in different laboratory prepared mixtures and in their pharmaceutical formulation. Statistical comparison between the results obtained by applying the proposed methods and the reported HPLC method was done, and it was found that there was no significant difference between them regarding both accuracy and precision. (author)

  9. The Rheological Properties of Lipid Monolayers Modulate the Incorporation of l-Ascorbic Acid Alkyl Esters.

    Science.gov (United States)

    Zulueta Díaz, Yenisleidy de Las Mercedes; Mottola, Milagro; Vico, Raquel V; Wilke, Natalia; Fanani, María Laura

    2016-01-19

    In this work, we tested the hypothesis that the incorporation of amphiphilic drugs into lipid membranes may be regulated by their rheological properties. For this purpose, two members of the l-ascorbic acid alkyl esters family (ASCn) were selected, ASC16 and ASC14, which have different rheological properties when organized at the air/water interface. They are lipophilic forms of vitamin C used in topical pharmacological preparations. The effect of the phase state of the host lipid membranes on ASCn incorporation was explored using Langmuir monolayers. Films of pure lipids with known phase states have been selected, showing liquid-expanded, liquid-condensed, and solid phases as well as pure cholesterol films in liquid-ordered state. We also tested ternary and quaternary mixed films that mimic the properties of cholesterol containing membranes and of the stratum corneum. The compressibility and shear properties of those monolayers were assessed in order to define its phase character. We found that the length of the acyl chain of the ASCn compounds induces differential changes in the rheological properties of the host membrane and subtly regulates the kinetics and extent of the penetration process. The capacity for ASCn uptake was found to depend on the phase state of the host film. The increase in surface pressure resultant after amphiphile incorporation appears to be a function of the capacity of the host membrane to incorporate such amphiphile as well as the rheological response of the film. Hence, monolayers that show a solid phase state responded with a larger surface pressure increase to the incorporation of a comparable amount of amphiphile than liquid-expanded ones. The cholesterol-containing films, including the mixture that mimics stratum corneum, allowed a very scarce ASCn uptake independently of the membrane diffusional properties. This suggests an important contribution of Cho on the maintenance of the barrier function of stratum corneum. PMID:26694518

  10. Ascorbic Acid Ameliorates Toxic Effects of Chlopyrifos on Testicular Functions of Albino Rats

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    Kolawole Victor Olorunshola

    2011-11-01

    Full Text Available Chlorpirifos (CPF is a widely used organophosphate insecticide for both agricultural and domestic purposes with attendant human exposures. Many authors have documented the toxic effects of CPF on the central nervous system. This study was designed to study the effect of CPF and the influence of coadministration of ascorbic acid (AA on the testicular functions of albino rats. Twenty five 2 months old male albino wistar rats were divided into 5 groups of 5 rats each (Group A-E. A (control received vegetable oil, B received 16.3 mg/kg CPF, C received 32.6 mg/kg CPF, D received 16.3 mg/kg CPF + AA 100 mg/kg and E received 32.6 mg/kg CPF + AA 100 mg/kg. Treatment was orally for a duration of 21 days. Thereafter, body weight, serum testosterone, testicular, epididymal and seminal vesicle weight, epididymal sperm concentration, sperm motility and histopathology of the testis, epidydimis and seminal vesicles were determined using standard methods. CPF caused a statistically significant change (p<0.05 in body weight, testicular weight, epididymal weight, sperm concentration, sperm motility and serum testosterone concentration. Seminal vesicle weight was not affected. Histopathological studies revealed reduced sperm reserve, fibrosis and fatty infiltration in the epididymis, seminiferous tubules and seminal vesicles respectively. Co-administration of AA significantly caused improvement in all the parameters measured. It is concluded that CPF caused testicular toxicity by possible oxidative stress which was reversed with co-administration of AA.

  11. Graphene decorated microelectrodes for simultaneous detection of ascorbic, dopamine, and folic acids by means of chemical vapor deposition

    Science.gov (United States)

    Namdar, N.; Hassanpour Amiri, M.; Dehghan Nayeri, F.; Gholizadeh, A.; Mohajerzadeh, S.

    2015-09-01

    In this paper, high quality and large area graphene layers were synthesized using thermal chemical vapour deposition on copper foil substrates. We use graphene incorporated electrodes to measure simultaneously ascorbic acid, dopamine and folic acid. Cyclic voltammetry and differential pulse voltammetry methods were used to evaluate electrochemical behaviour of the grown graphene layers. The graphene-modified electrode shows large electrochemical potential difference compared to bare gold electrodes with higher current responses. Also our fabricated electrodes configuration can be used easily for microfluidic analysis.

  12. Sorption of molybdoarsenates reduced by ascorbic acid with polyurethane foams based on ethers, esters, and their copolymers

    International Nuclear Information System (INIS)

    Sorption of molybdoarsenates reduced by ascorbic acid from aqueous solutions with polyurethane foams based on ethers (PUF-1), esters (PUF-2), and their copolymers (PUF-3) was studied in relation to the phase weight ratio and solution acidity. It is found that the isotherms of reduced molybdoarsenate sorption refer to the Langmuir isotherms. The sorption coefficients decrease in the series PUF-1>PUF-2>PUF-3. Maximum recovery of reduced molybdoarsenate on polyurethane foams is achieved at pH 0-2; concentration factor is up to 2.5x103

  13. Variation in the SLC23A1 gene does not influence cardiometabolic outcomes to the extent expected given its association with l-ascorbic acid1234

    Science.gov (United States)

    Wade, Kaitlin H; Forouhi, Nita G; Cook, Derek G; Johnson, Paul; McConnachie, Alex; Morris, Richard W; Rodriguez, Santiago; Ye, Zheng; Ebrahim, Shah; Padmanabhan, Sandosh; Watt, Graham; Bruckdorfer, K Richard; Wareham, Nick J; Whincup, Peter H; Chanock, Stephen; Sattar, Naveed; Lawlor, Debbie A; Davey Smith, George; Timpson, Nicholas J

    2015-01-01

    Background: Observational studies showed that circulating l-ascorbic acid (vitamin C) is inversely associated with cardiometabolic traits. However, these studies were susceptible to confounding and reverse causation. Objectives: We assessed the relation between l-ascorbic acid and 10 cardiometabolic traits by using a single nucleotide polymorphism in the solute carrier family 23 member 1 (SLC23A1) gene (rs33972313) associated with circulating l-ascorbic acid concentrations. The observed association between rs33972313 and cardiometabolic outcomes was compared with that expected given the rs33972313-l-ascorbic acid and l-ascorbic acid–outcome associations. Design: A meta-analysis was performed in the following 5 independent studies: the British Women's Heart and Health Study (n = 1833), the MIDSPAN study (n = 1138), the Ten Towns study (n = 1324), the British Regional Heart Study (n = 2521), and the European Prospective Investigation into Cancer (n = 3737). Results: With the use of a meta-analysis of observational estimates, inverse associations were shown between l-ascorbic acid and systolic blood pressure, triglycerides, and the waist-hip ratio [the strongest of which was the waist-hip ratio (?0.13-SD change; 95% CI: ?0.20-, ?0.07-SD change; P = 0.0001) per SD increase in l-ascorbic acid], and a positive association was shown with high-density lipoprotein (HDL) cholesterol. The variation at rs33972313 was associated with a 0.18-SD (95% CI: 0.10-, 0.25-SD; P = 3.34 × 10?6) increase in l-ascorbic acid per effect allele. There was no evidence of a relation between the variation at rs33972313 and any cardiometabolic outcome. Although observed estimates were not statistically different from expected associations between rs33972313 and cardiometabolic outcomes, estimates for low-density lipoprotein cholesterol, HDL cholesterol, triglycerides, glucose, and body mass index were in the opposite direction to those expected. Conclusions: The nature of the genetic association exploited in this study led to limited statistical application, but despite this, when all cardiometabolic traits were assessed, there was no evidence of any trend supporting a protective role of l-ascorbic acid. In the context of existing work, these results add to the suggestion that observational relations between l-ascorbic acid and cardiometabolic health may be attributable to confounding and reverse causation. PMID:25527764

  14. Simultaneous Determination of Ascorbic Acid, L-Dopa, Uric Acid, Insulin, and Acetylsalicylic Acid on Reactive Blue 19 and Multi-Wall Carbon Nanotube Modified Glassy Carbon Electrode

    Scientific Electronic Library Online (English)

    Navid, Nasirizadeh; Zahra, Shekari; Masoumeh, Tabatabaee; Masoud, Ghaani.

    2015-04-01

    Full Text Available A trifunctional electrochemical sensor was fabricated for simultaneous determination of ascorbic acid (AA), levodopa (LD), and insulin. This was done by modifying a glassy carbon electrode (GCE) with multi-walled carbon nanotubes and reactive blue 19 (RB-MWCNT-GCE). Cyclic voltammetry was used to in [...] vestigate the redox properties of this modified electrode. The electro-catalytic activity of the modified electrode was studied for the oxidation of AA, LD, and insulin. By differential pulse voltammetry (DPV), the detection limits of AA, LD, and insulin were estimated to be 0.45 µmol L -1, 0.37 µmol L-1, and 0.25 µmol L-1, respectively. In DPV measurements, the RB-MWCNT-GCE could separate the oxidation peak potentials of AA, LD, uric acid (UA), insulin, and acetylsalicylic acid (ASA) in a mixture. The practical utility of this modified electrode was demonstrated by detecting AA, LD, UA, insulin, and ASA in real samples.

  15. Oral high dose ascorbic acid treatment for one year in young CMT1A patients: a randomised, double-blind, placebo-controlled phase II trial

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    de Visser Marianne

    2009-11-01

    Full Text Available Abstract Background High dose oral ascorbic acid substantially improved myelination and locomotor function in a Charcot-Marie-Tooth type 1A mouse model. A phase II study was warranted to investigate whether high dose ascorbic acid also has such a substantial effect on myelination in Charcot-Marie-Tooth type 1A patients and whether this treatment is safe. Methods Patients below age 25 years were randomly assigned to receive placebo or ascorbic acid (one gram twice daily in a double-blind fashion during one year. The primary outcome measure was the change over time in motor nerve conduction velocity of the median nerve. Secondary outcome measures included changes in minimal F response latencies, compound muscle action potential amplitude, muscle strength, sensory function, Charcot-Marie-Tooth neuropathy score, and disability. Results There were no significant differences between the six placebo-treated (median age 16 years, range 13 to 24 and the five ascorbic acid-treated (19, 14 to 24 patients in change in motor nerve conduction velocity of the median nerve (mean difference ascorbic acid as opposed to placebo treatment of 1.3 m/s, confidence interval -0.3 to 3.0 m/s, P = 0.11 or in change of any of the secondary outcome measures over time. One patient in the ascorbic acid group developed a skin rash, which led to discontinuation of the study medication. Conclusion Oral high dose ascorbic acid for one year did not improve myelination of the median nerve in young Charcot-Marie-Tooth type 1A patients. Treatment was relatively safe. Trial registration Current Controlled Trials ISRCTN56968278, ClinicalTrials.gov NCT00271635.

  16. Chemical repair of base lesions, AP-sites, and strand breaks on plasmid DNA in dilute aqueous solution by ascorbic acid

    International Nuclear Information System (INIS)

    Highlights: •We report a novel mechanism of radiation protection of DNA by chemical activity of ascorbic acid. •The “chemical repair” of DNA damage was revealed using biochemical assay and chemical kinetics analysis. •We found that ascorbic acid significantly repairs precursors of nucleobase lesions and abasic sites. •However, ascorbic acid seldom repairs precursors of DNA-strand breaks. -- Abstract: We quantified the damage yields produced in plasmid DNA by ?-irradiation in the presence of low concentrations (10–100 ?M) of ascorbic acid, which is a major antioxidant in living systems, to clarify whether it chemically repairs radiation damage in DNA. The yield of DNA single strand breaks induced by irradiation was analyzed with agarose gel electrophoresis as conformational changes in closed circular plasmids. Base lesions and abasic sites were also observed as additional conformational changes by treating irradiated samples with glycosylase proteins. By comparing the suppression efficiencies to the induction of each DNA lesion, in addition to scavenging of the OH radicals derived from water radiolysis, it was found that ascorbic acid promotes the chemical repair of precursors of AP-sites and base lesions more effectively than those of single strand breaks. We estimated the efficiency of the chemical repair of each lesion using a kinetic model. Approximately 50–60% of base lesions and AP-sites were repaired by 10 ?M ascorbic acid, although strand breaks were largely unrepaired by ascorbic acid at low concentrations. The methods in this study will provide a route to understanding the mechanistic aspects of antioxidant activity in living systems

  17. Chemical repair of base lesions, AP-sites, and strand breaks on plasmid DNA in dilute aqueous solution by ascorbic acid

    Energy Technology Data Exchange (ETDEWEB)

    Hata, Kuniki [Department of Nuclear Engineering and Management, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Shirakatashirane, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Urushibara, Ayumi; Yamashita, Shinichi; Shikazono, Naoya; Yokoya, Akinari [Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Shirakatashirane, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Katsumura, Yosuke, E-mail: katsu@n.t.u-tokyo.ac.jp [Department of Nuclear Engineering and Management, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Nuclear Professional School, School of Engineering, The University of Tokyo, 2-22 Shirakatashirane, Tokai-mura, Naka-gun, Ibaraki 319-1188 (Japan)

    2013-05-03

    Highlights: •We report a novel mechanism of radiation protection of DNA by chemical activity of ascorbic acid. •The “chemical repair” of DNA damage was revealed using biochemical assay and chemical kinetics analysis. •We found that ascorbic acid significantly repairs precursors of nucleobase lesions and abasic sites. •However, ascorbic acid seldom repairs precursors of DNA-strand breaks. -- Abstract: We quantified the damage yields produced in plasmid DNA by ?-irradiation in the presence of low concentrations (10–100 ?M) of ascorbic acid, which is a major antioxidant in living systems, to clarify whether it chemically repairs radiation damage in DNA. The yield of DNA single strand breaks induced by irradiation was analyzed with agarose gel electrophoresis as conformational changes in closed circular plasmids. Base lesions and abasic sites were also observed as additional conformational changes by treating irradiated samples with glycosylase proteins. By comparing the suppression efficiencies to the induction of each DNA lesion, in addition to scavenging of the OH radicals derived from water radiolysis, it was found that ascorbic acid promotes the chemical repair of precursors of AP-sites and base lesions more effectively than those of single strand breaks. We estimated the efficiency of the chemical repair of each lesion using a kinetic model. Approximately 50–60% of base lesions and AP-sites were repaired by 10 ?M ascorbic acid, although strand breaks were largely unrepaired by ascorbic acid at low concentrations. The methods in this study will provide a route to understanding the mechanistic aspects of antioxidant activity in living systems.

  18. High-sensitivity ascorbic acid sensor using graphene sheet/graphene nanoribbon hybrid material as an enhanced electrochemical sensing platform.

    Science.gov (United States)

    Lavanya, J; Gomathi, N

    2015-11-01

    A novel electrode material of graphene sheet/graphene nanoribbon (GS/GNR) hybrid material was developed by incorporating graphene nanoribbons into graphene nanosheets through simultaneous chemical reduction of graphene oxide sheets and graphene oxide ribbons. The structure and properties of synthesized GS/GNR were characterized by transmission electron microscope, scanning electron microscope, X-ray diffraction, Brunauer Emmett Teller measurements and Fourier transform infrared spectroscopy. This work compares the electro catalytic performance of the GS/GNR, chemically reduced graphene oxide sheets (CRGOS) and GS/carbon nanotube (CNT) by modifying the glassy carbon electrode (GCE) using ascorbic acid (AA) as analyte. The electrochemical impedance spectroscopy revealed that the charge transfer resistance of GS/GNR modified electrode was less than that of CRGOS modified electrode and bare GCE. The cyclic voltammetric sensing of GS/GNR modified electrode towards AA was negatively shifted (0.08 V) compared to CRGOS, GS/CNT modified electrode and bare GCE (0.222, 0.150 and 0.666 V). This catalytic oxidation allows an amperometric detection of AA with a detection limit of 230 nM and sensitivity of 22 nA ?M(-1) cm(-2). GS/GNR modified GCE exhibited a high selectivity for ascorbic acid in the presence of other interferents like dopamine, uric acid and citric acid. PMID:26452874

  19. Monolayer covalent modification of 5-hydroxytryptophan on glassy carbon electrodes for simultaneous determination of uric acid and ascorbic acid

    International Nuclear Information System (INIS)

    5-Hydroxytryptophan (5-HTP) was covalently grafted on the surface of glassy carbon electrodes (GCEs) using cyclic voltammetric method in a phosphate buffer solution. The prepared electrode, denoded as 5-HTP/GCE, was characterized by X-ray photoelectron spectroscopy, cyclic voltammetry and differential pulse voltammetry (DPV). Tryptophan grafted GCE (TRP/GCE) and 5-hydroxytryptamine grafted GCE (5-HTP/GCE) were also prepared by the same method for comparison. It was found that the electrocatalytic activities toward the oxidation of uric acid (UA) and ascorbic acid (AA) was in the order of 5-HT/GCE > 5-HTP/GCE > TRP/GCE for UA oxidation and 5-HT/GCE 5-HTP/GCE > TRP/GCE for AA oxidation. However, the CV current sensitivity was estimated as 4:2:1 for 5-HTP/GCE:5-HT/GCE:TRP/GCE. The DPV peaks for UA and AA oxidation appeared at 0.07 V and 0.34 V versus SCE, respectively, allowing simultaneous determination in mixtures. A linearly response in the range of: 5.0 x 10-7 to 1.1 x 10-5 M with the detection limit (s/n = 3) of 2.8 x 10-7 M for UA determination, and a linear response in the range of: 5.0 x 10-6 to 1.0 x 10-4 M with the detection limit of 4.2 x 10-6 M for AA determination were obtained. This electrode was used for UA and AA determinations in human urine samples satisfactorily

  20. Development of a cell line from skin of goldfish, Carassius auratus, and effects of ascorbic acid on collagen deposition.

    Science.gov (United States)

    Lee, L E; Caldwell, S J; Gibbons, J

    1997-01-01

    Growth characteristics and collagen expression were investigated in GFSk-S1, a cell line derived from the skin of an adult goldfish (Carassius auratus). These cells are anchorage dependent, grow well in Leibovitz-15 medium with 10% fetal bovine serum, and have been subcultured routinely for 5 years. Cells at various passages have been successfully cryopreserved and thawed. GFSk-S1 cells show mainly a fibroblastic morphology at low density, but at confluence islands of epithelial-shaped cells appear among the fibroblastic cells. The cells require little maintenance, and cultures have been kept viable for more than 3 months without medium changes. Although best growth was observed at room temperature, cell proliferation still occurred at 28 degrees C, and a subline was maintained and passaged for over a year at 25 degrees C. Cells were exposed to various concentrations of ascorbic acid, and its effects on collagen secretion were monitored by light and electron microscopy. Under phase-contrast microscopy, confluent GFSk-S1 cells exposed to ascorbic acid at 50 micrograms/ml showed distinct development of fibres as early as 3 days after treatment. Histochemical staining for collagen demonstrated a thick network of fibres under a monolayer of ascorbic acid-treated GFSk-S1 cells, and observation by transmission electron microscopy showed collagen fibres with typical banding pattern. This cell line appears to show a stable genotype, as collagen expression was induced at all passages. GFSk-S1 could be useful for studies not only of regulation of protein synthesis, but also of cell differentiation and wound healing. PMID:9088943

  1. Protective Effect of Ascorbic Acid on Molecular Behavior Changes of Hemoglobin Induced by Magnetic Field Induced by Magnetic Field

    Directory of Open Access Journals (Sweden)

    Nahed S. Hassan

    2007-01-01

    Full Text Available With the use of electricity and industrialization of societies, humans are commonly exposed to static magnetic field induced by electric currents. The putative mechanisms by which Static Magnetic Field (SMF may affect biological systems is that of increasing free radical life span in organisms. To test this hypothesis, we investigate the effect of ascorbic acid (Vitamin C treatment on the changes in the molecular behavior of hemoglobin as a result of exposure of the animals to magnetic field in the occupation levels. By measuring the relative permittivity, dielectric loss, relaxation time, conductivity, radius and diffusion coefficient of aqueous solutions of hemoglobin. These measurements were calculated in the frequency range of (100 Hz-100 kHz to give more information about molecular behavior. Twenty four male albino rats were equally divided into four groups 1, 2, 3 and 4. Animals of group 1, were used as control, animals of group 2, were exposed to (0.2T magnetic field and that of group 3, 4, were treated with Ascorbic Acid by two doses group 3 (20 mg kg-1 body weight, group 4 (50 mg kg-1 body weight orally half hour before exposure to magnetic field. The sub chronic exposure expanded (1 h day-1 for 30 consecutive days. The results indicated that exposure of animals to magnetic field resulted in changes in the molecular behavior of hemoglobin molecule while treatment with ascorbic acid afforded comparatively more significant amelioration in these molecular changes, via decreasing the radical pair interaction of magnetic field with biological molecules.

  2. Electrochemical determination of dopamine in the presence of ascorbic acid based on the gold nanorods/carbon nanotubes composite film

    Energy Technology Data Exchange (ETDEWEB)

    Deng Chunyan, E-mail: dengchunyan81@126.com [Key Laboratory of Resources Chemistry of Nonferrous Metals, Central South University, Changsha, 410083 (China); Chen Jinzhuo; Yang Minghui [Key Laboratory of Resources Chemistry of Nonferrous Metals, Central South University, Changsha, 410083 (China); Nie Zhou [State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082 (China); Si Shihui [Key Laboratory of Resources Chemistry of Nonferrous Metals, Central South University, Changsha, 410083 (China)

    2011-10-01

    Highlights: > The GNR/CNT/GC electrode was fabricated simply. It has higher catalytic activity towards the oxidation of DA and ascorbic acid (AA). The selective determination of DA was carried out with low detection limit (0.8 nM, S/N = 3). The proposed method was feasible to detect the concentration of DA in human blood serum. - Abstract: In this paper, the gold nanorods (GNRs)/multiwalled carbon nanotubes (CNT) composite film-modified glassy carbon (GC) electrode was fabricated simply by the electrostatic interaction between the positively charged GNRs and the negatively charged CNT. And the GNRs/CNT/GC electrode was used for the selective and sensitive determination of dopamine (DA) in the presence of ascorbic acid (AA). It was found that the GNRs/CNT/GC electrode had higher catalytic activity towards the oxidation of DA and ascorbic acid (AA) comparing with the bare GC and CNT/GC electrodes. It may be due to the synergic effect of GNRs and CNT, because the surface area of the GNRs/CNT/GC electrode increased, the edge plan sites presented on the CNT surface can improve the electron transfer between the modified electrode and DA, and the rod-shaped gold may be served as the mediator for the oxidation of dopamine and provided the electrocatalytic ability. Moreover, the voltammetric peaks of AA and DA were separated enough at the GNRs/CNT/GC electrode, which was sufficiently enough for the selective determination of DA. Thus, the selective determination of DA was carried out with low detection limit (0.8 nM, S/N = 3). Also it was obtained that the proposed method was feasible to detect the concentration of DA in human blood serum. Therefore, it can be concluded that the GNRs/CNT modified electrode may be advantageous for the DA determination.

  3. Design and synthesis of molecularly imprinted polypyrrole based on nanoreactor SBA-15 for recognition of ascorbic acid.

    Science.gov (United States)

    Mehdinia, Ali; Aziz-Zanjani, Mohammad Ovais; Ahmadifar, Maryam; Jabbari, Ali

    2013-01-15

    Molecular imprinting is an attractive technique for preparing mimics of natural and biological receptors. Nevertheless, molecular imprinting for aqueous systems remains a challenge due to the hydrogen bonding between templates and functional monomers destroyed in the bulk water. The hydrogen bonding between templates and monomers are the most crucial factor governing recognition, particularly in non-covalent molecularly imprinted polymers. Using mesoporous materials for molecular imprinting is an effective approach to overcome this barrier and to remove the limitations of the traditional molecularly imprinted polymers which include incomplete template removal, small binding capacity, slow mass transfer, and irregular materials shape. Here, SBA-15 was used as a mesoporous silica material for synthesis of molecularly imprinted polypyrrole. The pyrrole monomers and template molecules were immobilized onto the SBA-15 hexagonal channels, and then polymerization occurred. The resulting nanocomposites were characterized by Fourier transform infrared (FT-IR) analysis, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) methods. In batch rebinding tests, the imprinted nanocomposites reached saturated adsorption within 100min and exhibited significant specific recognition toward the ascorbic acid (AA) with high adsorption capacity (83.7mg g(-1)). To further illustrate the recognition property of the imprinted nanocomposites, binary competitive and non-competitive adsorption experiments were performed with ascorbic acid, dopamine, paracetamol and epinephrine. The imprinting factors for these compounds in non-competitive adsorption experiments were 3.2, 1.5, 1.4 and 1.3, respectively. The results showed that the imprinted nanocomposites exhibited significant adsorption selectivity for the ascorbic acid against the related compounds. PMID:22871516

  4. Regulation of fruit ascorbic acid concentrations during ripening in high and low vitamin C tomato cultivars

    Directory of Open Access Journals (Sweden)

    Mellidou Ifigeneia

    2012-12-01

    Full Text Available Abstract Background To gain insight into the regulation of fruit ascorbic acid (AsA pool in tomatoes, a combination of metabolite analyses, non-labelled and radiolabelled substrate feeding experiments, enzyme activity measurements and gene expression studies were carried out in fruits of the ‘low-’ and ‘high-AsA’ tomato cultivars ‘Ailsa Craig’ and ‘Santorini’ respectively. Results The two cultivars exhibited different profiles of total AsA (totAsA, AsA + dehydroascorbate and AsA accumulation during ripening, but both displayed a characteristic peak in concentrations at the breaker stage. Substrate feeding experiments demonstrated that the L-galactose pathway is the main AsA biosynthetic route in tomato fruits, but that substrates from alternative pathways can increase the AsA pool at specific developmental stages. In addition, we show that young fruits display a higher AsA biosynthetic capacity than mature ones, but this does not lead to higher AsA concentrations due to either enhanced rates of AsA breakdown (‘Ailsa Craig’ or decreased rates of AsA recycling (‘Santorini’, depending on the cultivar. In the later stages of ripening, differences in fruit totAsA-AsA concentrations of the two cultivars can be explained by differences in the rate of AsA recycling activities. Analysis of the expression of AsA metabolic genes showed that only the expression of one orthologue of GDP-L-galactose phosphorylase (SlGGP1, and of two monodehydroascorbate reductases (SlMDHAR1 and SlMDHAR3 correlated with the changes in fruit totAsA-AsA concentrations during fruit ripening in ‘Ailsa Craig’, and that only the expression of SlGGP1 was linked to the high AsA concentrations found in red ripe ‘Santorini’ fruits. Conclusions Results indicate that ‘Ailsa Craig’ and ‘Santorini’ use complementary mechanisms to maintain the fruit AsA pool. In the low-AsA cultivar (‘Ailsa Craig’, alternative routes of AsA biosynthesis may supplement biosynthesis via L-galactose, while in the high-AsA cultivar (‘Santorini’, enhanced AsA recycling activities appear to be responsible for AsA accumulation in the later stages of ripening. Gene expression studies indicate that expression of SlGGP1 and two orthologues of SlMDHAR are closely correlated with totAsA-AsA concentrations during ripening and are potentially good candidates for marker development for breeding and selection.

  5. Lack of promotion of urinary bladder carcinogenesis by sodium bicarbonate and/or L-ascorbic acid in male ODS/Shi-od/od rats synthesizing alpha 2 mu-globulin but not L-ascorbic acid.

    Science.gov (United States)

    Mori, S; Murai, T; Hosono, M; Machino, S; Makino, S; Chou, C; Fukushima, S

    1997-08-01

    The study was designed to investigate whether sodium bicarbonate (NaHCO3) and/or L-ascorbic acid (AsA) promote urinary bladder carcinogenesis in male ODS/Shi-od/od (ODS) rats, which, unlike male F344 rats, are resistant to sodium L-ascorbate (Na-AsA)-promoting effects. Whereas F344 rats can synthesize AsA and alpha 2 mu-globulin (A2 mu-G), only A2 mu-G in produced in ODS rats. The two strains were given 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) in their drinking water for 2 wk and then were fed basal CA-1 diet supplemented with 3% NaHCO3 plus 5% AsA (NaHCO3 + AsA), 3% NaHCO3, 5% AsA, or no chemicals for 32 wk. ODS rats given BBN-NaHCO3 or BBN-(NaHCO3 + AsA) had only a few small carcinomas in the urinary bladder, like those receiving BBN alone or BBN-AsA. In contrast, F344 rats administered BBN-NaHCO3 or BBN-(NaHCO3 + AsA) had many more, larger, carcinoma than animals of the same strain given BBN alone or BBN-AsA. AsA alone did not have any effect in either strain. Administration of NaHCO3 alone or NaHCO3 + AsA was associated with significant elevation of urinary pH and Na+ concentration to the same extent in both strains but, again, AsA alone was without effect. NaHCO3 + AsA and AsA alone increased the urinary concentration of total ascorbic acid in both strains but the observed levels wer lower in ODS rats. The results indicate that ODS rats are resistant to the modifying effects of NaHCO3 and/or AsA on two-stage urinary bladder carcinogenesis, and thus that the susceptibility to the promotional activity of sodium-salt-type compounds may be regulated by factors other than A2 mu-G-synthesizing ability and urinary levels of pH, Na+ and total ascorbic acid. PMID:9350223

  6. Promotion of IL-4- and IL-5-dependent differentiation of anti-mu-primed B cells by ascorbic acid 2-glucoside.

    Science.gov (United States)

    Ichiyama, Kenji; Mitsuzumi, Hitoshi; Zhong, Ming; Tai, Akihiro; Tsuchioka, Akihiro; Kawai, Saeko; Yamamoto, Itaru; Gohda, Eiichi

    2009-02-21

    The stable ascorbic acid derivative 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G) was used to investigate the role of ascorbic acid (AA) in B cell differentiation in vitro. AA-2G is stable in a solution unlike AA but is hydrolyzed by cellular alpha-glucosidase to release AA. Mouse spleen B cells were primed for 2 days with an anti-mu antibody in the presence of interleukin (IL)-4 and IL-5 and then washed and recultured with AA-2G in the presence of IL-4 and IL-5. AA-2G, but not AA, dose-dependently increased IgM production, the greatest enhancement being 150% at concentrations of more than 0.5mM. In the absence of IL-4 and IL-5, primed B cells produced a negligible amount of IgM, and AA-2G had no effect. AA-2G-induced IgM production in the presence of IL-4 and IL-5 was inhibited by the alpha-glucosidase inhibitor castanospermine. Intracellular AA content, depleted during the priming period, increased by adding AA-2G at the start of reculture. Treatment of B cells with AA-2G resulted in an increase in the number of IgM-secreting cells, CD138-positive cells and CD45R/B220-negative cells. The number of viable cells in untreated cultures decreased gradually, but the decrease was significantly attenuated by AA-2G, resulting in about 70% more viable cells in AA-2G-treated cultures. AA-2G caused a slight but reproducible enhancement of DNA synthesis and a slight decrease in the number of cells with a sub-G1 DNA content. These results demonstrated that AA released from AA-2G enhanced cytokine-dependent IgM production in anti-mu-primed B cells and suggest that its effect is caused through promoting the differentiation of B cells to plasma cells and attenuating the gradual decrease in the number of viable cells. PMID:19201381

  7. Electrocatalytic Determination of Ascorbic Acid Using Glassy Carbon Modified with Nickel(II) Macrocycle Containing Dianionic Tetraazaannulene Ligand

    OpenAIRE

    KHORASANI-MOTLAGH, Mozhgan; NOROOZIFAR, Meissam

    2004-01-01

    A symmetric Ni(II) tetraaza macrocycle modified glassy electrode shows electrocatalytic activity for the oxidation of L-ascorbic acid at pH 7. It was shown the peak potential shifted to the negative by 250 mV compared with that for the bare electrode in the cyclic voltammograms. The calibration curve was linear up to 5 mM with a detection limit of 2.5 \\times 10-4 mM and RSD% better than 2.8%. Excipients used as additives in pharmaceutical formulations and foods did not interfere in ...

  8. Natural resistance to ascorbic acid induced oxidative stress is mainly mediated by catalase activity in human cancer cells and catalase-silencing sensitizes to oxidative stress

    Directory of Open Access Journals (Sweden)

    Klingelhoeffer Christoph

    2012-05-01

    Full Text Available Abstract Background Ascorbic acid demonstrates a cytotoxic effect by generating hydrogen peroxide, a reactive oxygen species (ROS involved in oxidative cell stress. A panel of eleven human cancer cell lines, glioblastoma and carcinoma, were exposed to serial dilutions of ascorbic acid (5-100 mmol/L. The purpose of this study was to analyse the impact of catalase, an important hydrogen peroxide-detoxifying enzyme, on the resistance of cancer cells to ascorbic acid mediated oxidative stress. Methods Effective concentration (EC50 values, which indicate the concentration of ascorbic acid that reduced the number of viable cells by 50%, were detected with the crystal violet assay. The level of intracellular catalase protein and enzyme activity was determined. Expression of catalase was silenced by catalase-specific short hairpin RNA (sh-RNA in BT-20 breast carcinoma cells. Oxidative cell stress induced apoptosis was measured by a caspase luminescent assay. Results The tested human cancer cell lines demonstrated obvious differences in their resistance to ascorbic acid mediated oxidative cell stress. Forty-five percent of the cell lines had an EC50 > 20 mmol/L and fifty-five percent had an EC50 50 of 2.6–5.5 mmol/L, glioblastoma cells were the most susceptible cancer cell lines analysed in this study. A correlation between catalase activity and the susceptibility to ascorbic acid was observed. To study the possible protective role of catalase on the resistance of cancer cells to oxidative cell stress, the expression of catalase in the breast carcinoma cell line BT-20, which cells were highly resistant to the exposure to ascorbic acid (EC50: 94,9 mmol/L, was silenced with specific sh-RNA. The effect was that catalase-silenced BT-20 cells (BT-20 KD-CAT became more susceptible to high concentrations of ascorbic acid (50 and 100 mmol/L. Conclusions Fifty-five percent of the human cancer cell lines tested were unable to protect themselves against oxidative stress mediated by ascorbic acid induced hydrogen peroxide production. The antioxidative enzyme catalase is important to protect cancer cells against cytotoxic hydrogen peroxide. Silenced catalase expression increased the susceptibility of the formerly resistant cancer cell line BT-20 to oxidative stress.

  9. Graphene ceramic composite as a new kind of surface-renewable electrode: application to the electroanalysis of ascorbic acid

    International Nuclear Information System (INIS)

    This study introduces a new surface-renewable electrode based on a sol–gel derived graphene ceramic composite. The electrode was prepared by dispersing graphene nanosheets into a solution of the sol–gel precursors containing methyl triethoxysilane in methanol and hydrochloric acid. During hydrolysis of methyl triethoxysilane, the graphene nanosheets are trapped in the gel. After moulding and drying the composite, it can be used as a surface-renewable electrode to which we refer as a graphene ceramic composite electrode (GCCE). Cyclic voltammograms of the hexacyanoferrate(II/III) model redox system at the GCCE were compared to those obtained with a conventional carbon ceramic electrode and showed a highly improved electron transfer rate at the GCCE. The electrocatalytic oxidation of ascorbic acid as a model analyte was then studied at working potential of 50 mV and over the 3–84 μM concentration range. It revealed a sensitivity of 6.06 μA μM−1 cm−2 and a detection limit of 0.82 μM. The GCCE was successfully applied to the determination of ascorbic acid in orange juice and urine samples. Advantages such as good mechanical and chemical stability, ease of fabrication, and reproducible preparation make the GCCE a potentially useful and widely applicable renewable electrode for use in routine analysis. (author)

  10. L-dehydroascorbic acid can substitute L-ascorbic acid as dietary vitamin C source in guinea pigs

    OpenAIRE

    Frikke-Schmidt, Henriette Rønne; Tveden-Nyborg, Pernille; Lykkesfeldt, Jens

    2016-01-01

    Vitamin C deficiency globally affects several hundred million people and has been associated with increased morbidity and mortality in numerous studies. In this study, bioavailability of the oxidized form of vitamin C (l-dehydroascorbic acid or DHA)-commonly found in vitamin C containing food products prone to oxidation-was studied. Our aim was to compare tissue accumulation of vitamin C in guinea pigs receiving different oral doses of either ascorbate or DHA. In all tissues tested (plasma, l...

  11. Effect of turmeric powder (Curcuma longa L.) and ascorbic acid on physical characteristics and oxidative status of fresh and stored rabbit burgers.

    Science.gov (United States)

    Mancini, Simone; Preziuso, Giovanna; Dal Bosco, Alessandro; Roscini, Valentina; Szendr?, Zsolt; Fratini, Filippo; Paci, Gisella

    2015-12-01

    The objective of this study was to evaluate the effect of Curcuma longa powder and ascorbic acid on some quality traits of rabbit burgers. The burgers (burgers control with no additives; burgers with 3.5 g of turmeric powder/100g meat; burgers with 0.1g of ascorbic acid/100g meat) were analyzed at Days 0 and 7 for pH, color, drip loss, cooking loss, fatty acid profile, TBARS, antioxidant capacity (ABTS, DPPH and FRAP) and microbial growth. The addition of turmeric powder modified the meat color, produced an antioxidant capacity similar to ascorbic acid and determined a lower cooking loss than other formulations. Turmeric powder might be considered as a useful natural antioxidant, increasing the quality and extending the shelf life of rabbit burgers. PMID:26188362

  12. The novel Arabidopsis thaliana svt2 suppressor of the ascorbic acid-deficient mutant vtc1-1 exhibits phenotypic and genotypic instability [v1; ref status: indexed, http://f1000r.es/o2

    Directory of Open Access Journals (Sweden)

    Chase F Kempinski

    2013-01-01

    Full Text Available Ascorbic acid is a potent antioxidant that detoxifies reactive oxygen species when plants are exposed to unfavorable environmental conditions. In addition to its antioxidant properties, ascorbic acid and its biosynthetic precursors fulfill a variety of other physiological and molecular functions. A mutation in the ascorbic acid biosynthesis gene VTC1, which encodes GDP-mannose pyrophosphorylase, results in conditional root growth inhibition in the presence of ammonium. To isolate suppressors of vtc1-1, which is in the Arabidopsis Columbia-0 background, seeds of the mutant were subjected to ethyl methanesulfonate mutagenesis. A suppressor mutant of vtc1-1 2, svt2, with wild-type levels of ascorbic acid and root growth similar to the wild type in the presence of ammonium was isolated. Interestingly, svt2 has Arabidopsis Landsberg erecta features, although svt2 is delayed in flowering and has an enlarged morphology. Moreover, the svt2 genotype shares similarities with Ler polymorphism markers and sequences, despite the fact that the mutant derived from mutagenesis of Col-0 vtc1-1 seed. We provide evidence that svt2 is not an artifact of the experiment, a contamination of Ler seed, or a result of outcrossing of the svt2 mutant with Ler pollen. Instead, our results show that svt2 exhibits transgenerational genotypic and phenotypic instability, which is manifested in a fraction of svt2 progeny, producing revertants that have Col-like phenotypic and genotypic characteristics. Some of those Col-like revertants then revert back to svt2-like plants in the subsequent generation. Our findings have important implications for undiscovered phenomena in transmitting genetic information in addition to the Mendelian laws of inheritance. Our results suggest that stress can trigger a genome restoration mechanism that could be advantageous for plants to survive environmental changes for which the ancestral genes were better adapted.

  13. Ácido L-ascórbico: reações de complexação e de óxido-redução com alguns íons metálicos de transição / L-ascorbic acid: complexation and redox reactions with some transition metal ions

    Scientific Electronic Library Online (English)

    Adalgiza, Fornaro; Nina, Coichev.

    1998-10-01

    Full Text Available [...] Abstract in english The strong reducing action of L-ascorbic acid (Vitamin C) are of fundamental interest in biochemical and related process. The oxidation of ascorbic acid by molecular oxygen and others oxidants are of fundamental importance, involving the intervention of transition metal ions as catalysts and the for [...] mation transition metal complexes of ascorbic acid as intermediates. The present article is intended to cover some aspects of the reactions of ascorbic acid and related compounds involving some transition metal ions.

  14. Effects of ascorbic acid and glucose oxidase levels on the viability of probiotic bacteria and the physical and sensory characteristics in symbiotic ice-cream

    Directory of Open Access Journals (Sweden)

    M. B. Ak?n

    2015-05-01

    Full Text Available In this study, the effects of addition of different amounts of ascorbic acid and glucose oxidase on the properties of symbiotic ice cream were investigated. Ice-cream containing inulin (2 % (w/w was produced by mixing fortified milk fermented with probiotic strains with the ice-cream mixes containing different ascorbic acid and glucose oxidase concentrations (0.025, 0.05, 0.1 (w/w. The cultures were grown (37 °C, 12 h in UHT skimmed milk. The fermented milk was added to the ice-cream mix up to a level of 10 % w/w. Increasing the concentration of ascorbic acid stimulated the growth of Lactobacillus acidophilus LA-5 (L. acidophilus and Bifidobacterium animalis subsp. lactis BB-12 (Bifidobacterium BB-12. On contrary, increasing the concentration of glucose oxidase negatively affected the growth of L. acidophilus and Bifidobacterium BB-12. However, both, ascorbic acid and glucose oxidase concentration had no effect on physical and sensory properties of ice cream. The results suggested that the addition of ascorbic acid stimulated the growth of L. acidophilus and Bifidobacterium BB-12 and could be recommended for ice cream production.

  15. Losses of Ascorbic Acid During Storage of Fresh Tubers, Frying, Packaging and Storage of Potato Crisps from Four Kenyan Potato Cultivars

    Directory of Open Access Journals (Sweden)

    J.N. Kabira

    2011-01-01

    Full Text Available The ascorbic acid (AA, vitamin C levels of tubers was determined in four Kenyan potato cultivars (Dutch Robyjn, Tigoni, 393385.39 and 391691.96 grown under standard cultural conditions and the effect of storage on fresh tubers was evaluated. Tubers were processed into crisps and the effect of frying temperature, package type, storage temperature and time were also determined. There was significant (p=0.05 variation due to cultivar and storage condition was found to affect the levels of ascorbic acid in fresh tubers. There was significant (p=0.05 reduction on the level of ascorbic acid (45% on the average in all the cultivars when tubers were fried into crisps. Packaging type and storage temperature significantly (p=0.05 influenced the amount of ascorbic acid retained by crisps within the storage period. It is therefore important for processors to choose lower frying temperature and proper packaging for maximum vitamin C retention. Storage of potato crisps at temperatures beyond 30C results in lower levels of ascorbic acid retention.

  16. Simultaneous voltammetric determination of paracetamol and ascorbic acid using a boron-doped diamond electrode modified with Nafion and lead films.

    Science.gov (United States)

    Tyszczuk-Rotko, Katarzyna; B?czkowska, Ilona; Wójciak-Kosior, Magdalena; Sowa, Ireneusz

    2014-11-01

    The paper describes the fabrication and application of a novel sensor (a boron-doped diamond electrode modified with Nafion and lead films) for the simultaneous determination of paracetamol and ascorbic acid by differential pulse voltammetry. The main advantage of the lead film and polymer covered boron-doped diamond electrode is that the sensitivity of the stripping responses is increased and the separation of paracetamol and ascorbic acid signals is improved due to the modification of the boron-doped diamond surface by the lead layer. Additionally, the repeatability of paracetamol and ascorbic acid signals is improved by the application of the Nafion film coating. In the presence of oxygen, linear calibration curves were obtained in a wide concentration range from 5×10(-7) to 2×10(-4) mol L(-1) for paracetamol and from 1×10(-6) to 5×10(-4) mol L(-1) for ascorbic acid. The analytical utility of the differential pulse voltammetric method elaborated was tested in the assay of paracetamol and ascorbic acid in commercially available pharmaceutical formulations and the method was validated by high performance liquid chromatography coupled with diode array detector. PMID:25127609

  17. Volumetric properties of (ascorbic acid + polyethylene glycol 3350 + water) systems at T = (288.15, 298.15, and 308.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Sahin, Melike [Chemistry Department, Akdeniz University, 07058 Antalya (Turkey); Ayranci, Erol, E-mail: eayranci@akdeniz.edu.t [Chemistry Department, Akdeniz University, 07058 Antalya (Turkey)

    2011-02-15

    Density and ultrasound speed were measured accurately for binary ascorbic acid-water and ternary ascorbic acid-water-polyethylene glycol 3350 (PEG3350) solutions at T = (288.15, 298.15, and 308.15) K. The data were used to evaluate thermodynamic properties as apparent molar volumes, V{sub {phi}}, and apparent molar isentropic compressions, K{sub S{Phi}}, of ascorbic acid in water and in aqueous PEG3350 solutions. Infinite dilution values of these parameters, V{sub {phi}}{sup 0} and K{sub S{Phi}}{sup 0}, were obtained from their plots as a function of molality and have been utilized in obtaining transfer volumes and transfer compressions of ascorbic acid from water to PEG3350 solutions at various weight percentages. All transfer volumes and compressions at infinite dilution were found to be positive, to increase with weight per cent of PEG3350 and to decrease with temperature. Apparent molar isobaric expansions at infinite dilution were derived from the temperature dependence of V{sub {phi}}{sup 0} values. The results were interpreted in terms of ascorbic acid-water-PEG3350 interactions.

  18. Volumetric properties of (ascorbic acid + polyethylene glycol 3350 + water) systems at T = (288.15, 298.15, and 308.15) K

    International Nuclear Information System (INIS)

    Density and ultrasound speed were measured accurately for binary ascorbic acid-water and ternary ascorbic acid-water-polyethylene glycol 3350 (PEG3350) solutions at T = (288.15, 298.15, and 308.15) K. The data were used to evaluate thermodynamic properties as apparent molar volumes, V?, and apparent molar isentropic compressions, KS?, of ascorbic acid in water and in aqueous PEG3350 solutions. Infinite dilution values of these parameters, V?0 and KS?0, were obtained from their plots as a function of molality and have been utilized in obtaining transfer volumes and transfer compressions of ascorbic acid from water to PEG3350 solutions at various weight percentages. All transfer volumes and compressions at infinite dilution were found to be positive, to increase with weight per cent of PEG3350 and to decrease with temperature. Apparent molar isobaric expansions at infinite dilution were derived from the temperature dependence of V?0 values. The results were interpreted in terms of ascorbic acid-water-PEG3350 interactions.

  19. Radiation protection by 6-palmitoyl ascorbic acid-2-glucoside: studies on DNA damage in vitro, ex vivo, in vivo and oxidative stress in vivo.

    Science.gov (United States)

    Chandrasekharan, Dhanya K; Kagiya, Tsutomu V; Nair, Cherupally Krishnan Krishnan

    2009-05-01

    A palmitoyl derivative of ascorbic acid 2-glucoside, 6-palmitoyl ascorbic acid-2-glucoside (PAsAG), which possess good antioxidant properties, is examined for radioprotection in vitro, ex vivo and in vivo models. PAsAG protected plasmid DNA from gamma-radiation induced damages under in vitro conditions. Presence of 1.6 mM PAsAG inhibited the disappearance of ccc (covalently closed circular) form of plasmid pBR322 with a dose modifying factor of 1.5. Comet assay studies on mouse spleen cells exposed to 6 Gy gamma-radiation (ex vivo) in presence and absence of PAsAG revealed that cellular DNA was effectively protected by this compound from radiation induced damages. Oral administration of 80 mg/kg body weight of PAsAG to mice 1 hour prior to 6 Gy whole body gamma-radiation exposure, efficiently protected cellular DNA in tissues such as spleen, bone marrow and blood, from radiation induced damages as indicated by alkaline comet assay. Oxidative stress in tissues such as liver and brain of mice, following whole body exposure to various doses of gamma-radiation (2-8 Gy), monitored as levels of GSH and peroxidation of lipids, were found considerably reduced when PAsAG was orally administered (80 mg/kg body weight) to the mice one hour prior to the radiation exposure. PAsAG administration improved the per cent survival of mice following exposure to 10 Gy whole body gamma-radiation. Thus PAsAG could act as a radioprotector under in vitro, ex vivo and in vivo conditions of ionizing-radiation exposure. PMID:19384055

  20. Radiation protection by 6-palmitoyl ascorbic acid-2-glucoside. Studies on DNA damage in vitro, ex vivo, in vivo and oxidative stress in vivo

    International Nuclear Information System (INIS)

    A palmitoyl derivative of ascorbic acid 2-glucoside, 6-palmitoyl ascorbic acid-2-glucoside (PAsAG), which possess good antioxidant properties, is examined for radioprotection in vitro, ex vivo and in vivo models. PAsAG protected plasmid DNA from gamma-radiation induced damages under in vitro conditions. Presence of 1.6 mM PAsAG inhibited the disappearance of ccc (covalently closed circular) form of plasmid pBR322 with a dose modifying factor of 1.5. Comet assay studies on mouse spleen cells exposed to 6 Gy gamma-radiation (ex vivo) in presence and absence of PAsAG revealed that cellular DNA was effectively protected by this compound from radiation induced damages. Oral administration of 80 mg/kg body weight of PAsAG to mice 1 hour prior to 6 Gy whole body gamma-radiation exposure, efficiently protected cellular DNA in tissues such as spleen, bone marrow and blood, from radiation induced damages as indicated by alkaline comet assay. Oxidative stress in tissues such as liver and brain of mice, following whole body exposure to various doses of gamma-radiation (2-8 Gy), monitored as levels of glutathione (GSH) and peroxidation of lipids, were found considerably reduced when PAsAG was orally administered (80 mg/kg body weight) to the mice one hour prior to the radiation exposure. PAsAG administration improved the per cent survival of mice following exposure to 10 Gy whole body gamma-radiation. Thus PAsAG could act as a radioprotector under in vitro, ex vivo and in vivo conditions of ionizing-radiation exposure. (author)

  1. Phytotoxicity of multi-walled carbon nanotubes on red spinach (Amaranthus tricolor L) and the role of ascorbic acid as an antioxidant

    Energy Technology Data Exchange (ETDEWEB)

    Begum, Parvin [Laboratory of Environmental Medical Chemistry, Graduate School of Environmental Science, Hokkaido University, Sapporo 060-0810 (Japan); Fugetsu, Bunshi, E-mail: hu@ees.hokudai.ac.jp [Laboratory of Environmental Medical Chemistry, Graduate School of Environmental Science, Hokkaido University, Sapporo 060-0810 (Japan)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer MWNTs are selected for study of the systemic toxicity and the potential influence on red spinach. Black-Right-Pointing-Pointer Microscopic observation revealed some adverse effects on root and leaf. Black-Right-Pointing-Pointer Cell damage were detected on 15 days after the exposure to MWNTs. Black-Right-Pointing-Pointer ROS increase ceased once ascorbic acid was added into media. Black-Right-Pointing-Pointer Oxidative stress seems to be the key element responsible for causing the toxicity. - Abstract: Carbon nanotubes (CNTs) are a novel nanomaterial with wide potential applications; however the adverse effects of CNTs following environmental exposure have recently received significant attention. Herein, we explore the systemic toxicity and potential influence of 0-1000 mg L{sup -1} the multi-walled CNTs on red spinach. The multi-walled CNTs exposed plants exhibited growth inhibition and cell death after 15 days of hydroponic culture. The multi-walled CNTs had adverse effects on root and leaf morphology, as observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Raman spectroscopy detected the multi-walled CNTs in leaves. Biomarkers of nanoparticle toxicity, reactive oxygen species (ROS), and cell damage in the red spinach were greatly increased 15 days post-exposure to the multi-walled CNTs. These effects were reversed when the multi-walled CNTs were supplemented with ascorbic acid (AsA), suggesting a role of ROS in the multl-walled CNT-induced toxicity and that the primary mechanism of the multi-walled CNTs' toxicity is oxidative stress.

  2. Inhibitory action of antioxidants (ascorbic acid or ?-tocopherol on seizures and brain damage induced by pilocarpine in rats Ação inibitória de antioxidantes (ácido ascórbico e ?-tocoferol nas convulsões e dano cerebral em ratos induzidos pela pilocarpina

    Directory of Open Access Journals (Sweden)

    Adriana da Rocha Tomé

    2010-06-01

    Full Text Available Temporal lobe epilepsy is the most common form of epilepsy in humans. Oxidative stress is a mechanism of cell death induced by seizures. Antioxidant compounds have neuroprotective effects due to their ability to inhibit free radical production. The objectives of this work were to comparatively study the inhibitory action of antioxidants (ascorbic acid or ?-tocopherol on behavioral changes and brain damage induced by high doses of pilocarpine, aiming to further clarify the mechanism of action of these antioxidant compounds. In order to determinate neuroprotective effects, we studied the effects of ascorbic acid (250 or 500 mg/kg, i.p. and ?-tocopherol (200 or 400 mg/kg, i.p. on the behavior and brain lesions observed after seizures induced by pilocarpine (400 mg/kg, i.p., P400 model in rats. Ascorbic acid or ?-tocopherol injections prior to pilocarpine suppressed behavioral seizure episodes. These findings suggested that free radicals can be produced during brain damage induced by seizures. In the P400 model, ascorbic acid and ?-tocopherol significantly decreased cerebral damage percentage. Antioxidant compounds can exert neuroprotective effects associated with inhibition of free radical production. These results highlighted the promising therapeutic potential of ascorbic acid and ?-tocopherol in treatments for neurodegenerative diseases.A epilepsia de lobo temporal é a mais comum forma de epilepsia em humanos. O estresse oxidativo é um dos mecanismos de morte celular induzida pelas crises convulsivas. Os compostos antioxidantes apresentam efeitos neuroprotetores devido à sua capacidade de inibir a produção de radicais livres. Os objetivos do presente trabalho foram estudar de forma comparativa a ação inibitória de antioxidantes (ácido ascórbico e ?-tocoferol sobre as alterações comportamentais e histopatológicas no hipocampo de ratos após convulsões induzidas pela pilocarpina. A fim de determinar os efeitos neuroprotetores destas drogas, o presente trabalho estudou os efeitos do ácido ascórbico (250 ou 500 mg/kg, i.p. e do ?-tocoferol (200 ou 400 mg/kg, i.p. sobre o comportamento e as lesões cerebrais observados após convulsões induzidas pela pilocarpina (400 mg/kg, i.p., P400, em ratos. As injeções de ácido ascórbico ou ?-tocoferol antes da administração de pilocarpina reduzem o número de animais que convulsionam. Estes achados sugerem que os radicais livres podem induzir o desenvolvimento de lesão cerebral durante as crises epilépticas. No modelo P400, o ácido ascórbico e o ?-tocoferol, diminuem significativamente os danos cerebrais. Os compostos antioxidantes podem exercer efeitos neuroprotetores, e esses resultados podem estar associados à inibição da produção de radicais livres. Estes resultados sugerem um promissor potencial terapêutico tanto para o ácido ascórbico quanto para o ?-tocoferol no tratamento de doenças neurodegenerativas.

  3. Inhibitory action of antioxidants (ascorbic acid or ?-tocopherol) on seizures and brain damage induced by pilocarpine in rats / Ação inibitória de antioxidantes (ácido ascórbico e ?-tocoferol) nas convulsões e dano cerebral em ratos induzidos pela pilocarpina

    Scientific Electronic Library Online (English)

    Adriana da Rocha, Tomé; Paulo Michel Pinheiro, Ferreira; Rivelilson Mendes de, Freitas.

    2010-06-01

    Full Text Available A epilepsia de lobo temporal é a mais comum forma de epilepsia em humanos. O estresse oxidativo é um dos mecanismos de morte celular induzida pelas crises convulsivas. Os compostos antioxidantes apresentam efeitos neuroprotetores devido à sua capacidade de inibir a produção de radicais livres. Os ob [...] jetivos do presente trabalho foram estudar de forma comparativa a ação inibitória de antioxidantes (ácido ascórbico e ?-tocoferol) sobre as alterações comportamentais e histopatológicas no hipocampo de ratos após convulsões induzidas pela pilocarpina. A fim de determinar os efeitos neuroprotetores destas drogas, o presente trabalho estudou os efeitos do ácido ascórbico (250 ou 500 mg/kg, i.p.) e do ?-tocoferol (200 ou 400 mg/kg, i.p.) sobre o comportamento e as lesões cerebrais observados após convulsões induzidas pela pilocarpina (400 mg/kg, i.p., P400), em ratos. As injeções de ácido ascórbico ou ?-tocoferol antes da administração de pilocarpina reduzem o número de animais que convulsionam. Estes achados sugerem que os radicais livres podem induzir o desenvolvimento de lesão cerebral durante as crises epilépticas. No modelo P400, o ácido ascórbico e o ?-tocoferol, diminuem significativamente os danos cerebrais. Os compostos antioxidantes podem exercer efeitos neuroprotetores, e esses resultados podem estar associados à inibição da produção de radicais livres. Estes resultados sugerem um promissor potencial terapêutico tanto para o ácido ascórbico quanto para o ?-tocoferol no tratamento de doenças neurodegenerativas. Abstract in english Temporal lobe epilepsy is the most common form of epilepsy in humans. Oxidative stress is a mechanism of cell death induced by seizures. Antioxidant compounds have neuroprotective effects due to their ability to inhibit free radical production. The objectives of this work were to comparatively study [...] the inhibitory action of antioxidants (ascorbic acid or ?-tocopherol) on behavioral changes and brain damage induced by high doses of pilocarpine, aiming to further clarify the mechanism of action of these antioxidant compounds. In order to determinate neuroprotective effects, we studied the effects of ascorbic acid (250 or 500 mg/kg, i.p.) and ?-tocopherol (200 or 400 mg/kg, i.p.) on the behavior and brain lesions observed after seizures induced by pilocarpine (400 mg/kg, i.p., P400 model) in rats. Ascorbic acid or ?-tocopherol injections prior to pilocarpine suppressed behavioral seizure episodes. These findings suggested that free radicals can be produced during brain damage induced by seizures. In the P400 model, ascorbic acid and ?-tocopherol significantly decreased cerebral damage percentage. Antioxidant compounds can exert neuroprotective effects associated with inhibition of free radical production. These results highlighted the promising therapeutic potential of ascorbic acid and ?-tocopherol in treatments for neurodegenerative diseases.

  4. Production of {sup 61}Cu using natural cobalt target and its separation using ascorbic acid and common anion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    Das, Sujata Saha; Chattopadhyay, Sankha; Barua, Luna [Radiopharmaceuticals Laboratory, Board of Radiation and Isotope Technology (BRIT), Variable Energy Cyclotron Centre (VECC), Kolkata 700064 (India); Das, Malay Kanti, E-mail: mkdas@vecc.gov.in [Radiopharmaceuticals Laboratory, Board of Radiation and Isotope Technology (BRIT), Variable Energy Cyclotron Centre (VECC), Kolkata 700064 (India)

    2012-02-15

    {sup 61}Cu was produced by {sup nat}Co({alpha}, xn){sup 61}Cu reaction. {sup 61}Cu production yield was 89.5 MBq/{mu}Ah (2.42 mCi/{mu}Ah) at the end of irradiation (EOI). A simple radiochemical separation method using anion exchange resin and ascorbic acid has been employed to separate the product radionuclide from inactive target material and co-produced non-isotopic impurities. The radiochemical separation yield was about 90%. Radiochemical purity of {sup 61}Cu was >99% 1 h after EOI. Final product was suitable for making complex with N{sub 2}S{sub 2} type of ligands. - Highlights: Black-Right-Pointing-Pointer High purity, no-carrier added {sup 61}Cu produced from natural cobalt target. Black-Right-Pointing-Pointer {sup 61}Cu separated from impurities using anion exchange resin and ascorbic acid. Black-Right-Pointing-Pointer {sup 61}Cu preparation was successfully used to label N{sub 2}S{sub 2}-type of ligand.

  5. Furan Occurrence in Starchy Food Model Systems Processed at High Temperatures: Effect of Ascorbic Acid and Heating Conditions

    DEFF Research Database (Denmark)

    Mariotti, Mari?a; Granby, Kit

    2012-01-01

    Furan, a potential carcinogen, has been detected in highly consumed starchy foods, such as bread and snacks; however, research on furan generation in these food matrixes has not been undertaken, thus far. The present study explored the effect of ascorbic acid addition and cooking methods (frying and baking) over furan occurrence and its relation with the non-enzymatic browning in a wheat flour starchy food model system. Results showed that furan generation significantly increased in the presence of ascorbic acid after 7 min of heating (p <0.05). The strongest effect was observed for baked products. Additionally, the furan content in fried products increased with the increase of the oil uptake levels. As for Maillard reactions, in general, the furan level in all samples linearly correlated with their degree of non-enzymatic browning, represented by L* and a* color parameters (e.g., wheat flour baked samples showed a R2 of 0.88 and 0.87 for L* and a*, respectively), when the sample moisture content decreased during heating.

  6. D-glucosone and L-sorbosone as putative intermediates in the biosynthesis of L-ascorbic acid in plants

    International Nuclear Information System (INIS)

    In plants, biosynthesis of L-ascorbic acid (AA) from D-glucose (glc) proceeds without carbon chain inversion. This requires oxidation of C1 and C2, and epimerization at C5. Neither sequence of reactions nor enzymes involved is yet known. To examine the overall reaction the authors fed D-[6-14C]glucosone to bean seedlings. It was converted to AA as effectively as [6-14C]glc with virtually no redistribution of label into the opposite terminal carbon. In other studies, a NADP-dependent L-sorbosone dehydrogenase that synthesized AA was isolated from bean and spinach leaves. Partial purification by precipitation at 45-55% (NH4)2SO4, fractionation on DEAE cellulose, and molecular sieving on Sephadex G-200 gave 30-fold purification. The enzyme was stable at -200C for several months. The apparent Km for sorbosone (0.9 mM NADP+) was 11.3+/-1.9 mM and for NADP+ (50 mM sorbosone) was 145+/-47 ?M. The relatively high Km's may reflect a two-step process or selection of a minor isomeric forms or sorbosone. A pathway (possibly involving phosphorylated intermediates) is suggested: D-Glucose?D-Glucosone?L-Sorbosone?L-Ascorbic acid

  7. Studies of effect of heterocyclic dyes in photogalvanic cells for solar energy conversion and storage: NaLS-ascorbic acid system

    Indian Academy of Sciences (India)

    K R Genwa; Anju Chouhan

    2004-11-01

    The photogalvanic effect has been studied in three systems using photogalvanic cells and NaLS-ascorbic acid-azur A, NaLS-ascorbic acid-azur B, NaLS-ascorbic acid-azur C systems. The photopotential and photocurrent generated by these systems are 770.0, 971.0, 623.0 mV and 160.0, 185.0, 145.0 A respectively. The effects of different parameters on the electrical outputs of the cell have been observed and current-voltage characteristics of the cell studied, and a mechanism has been proposed for the generation of photocurrent in photogalvanic cells. The conversion efficiencies for azur A, azur B and azur C are 0.5461, 0.9646 and 0.4567% and storage capacity 110, 135 and 95 min respectively.

  8. Determination by HPLC of ascorbic acid and tocopherols in fruits / Determinação de ácido ascórbico e tocoferóis em frutas por CLAE

    Directory of Open Access Journals (Sweden)

    Rui Carlos Zambiazi

    2010-07-01

    Full Text Available The fruits and vegetables are recommended for human feeding due to the richness of antioxidant compounds. The bioactive compounds from the diet, such as vitamins C and E are important to reduce the speed of initiation or prevent the spread of free radicals. The objective of the work was to evaluate the ascorbic acid and tocopherol content of selections of Pitanga (Eugenia uniflora L., butiá (Butiá capitata, blackberry (Rubus spp, blueberry (Vaccium Reade ashei, loquat (Eribrotia japônica, jambolan (Eugenia jambolana, purple araçá (Psidium rufum, physalis (Physalis peruviana, pear (Pyrus communis and peaches (Prunus persica. The fruits were from 2006/2007/2008 harvest, which were obtained in Pelotas (RS region. The tocopherol analyses were performed according Rodrigues-Amaya (1999, and ascorbic acid according Vinci, Botre e Ruggieri (1995. The tocopherol and ascorbic acid identification and quantification was performed by high-efficiency liquid chromatography system (HPLC, using a fluorescent detector for tocopherol (excitation of 290 nm and emission of 330 nm and a UV-Visible (254 nm for ascorbic acid. The blackberry cv. Tupy showed the highest tocopherols content (8,251 ?g.g-1 fruit when compared with the other fruit content. The tocopherol was not found in pears and peaches of cv. Sensação and cv. Granada. The ascorbic acid content ranged from 9,291 mg.g-1 fruit for the physalis to 0,013 mg.g-1 fruit for the jambolan. It was concluded that the fruits are good sources of bioactive compounds.As frutas e as hortaliças são recomendadas na alimentação humana pela riqueza em compostos nutritivos e também pela presença de compostos que apresentam efeito antioxidante. Os compostos bioativos adquiridos através da dieta, como a vitamina C e a vitamina E, além do aspecto nutritivo, são importantes para reduzir a velocidade de iniciação ou prevenir a propagação de radicais livres. O objetivo deste estudo foi avaliar os teores de ácido ascórbico e de tocoferóis, de seleções de pitanga (Eugenia uniflora L., butiá (Butiá capitata, amora-preta (Rubus spp, mirtilo (Vaccium ashei Reade, nêspera (Eribrotia japônica, jambolão (Eugenia jambolana, araçá roxo (Psidium rufum, physalis (Physalis peruviana, pêra (Pyrus communis e pêssegos (Prunus persica. As frutas utilizadas foram das safras 2006/2007/2008, obtidas na região de Pelotas/RS. A análise dos tocoferóis foi realizada segundo Rodrigues-Amaya (1999, e do ácido ascórbico segundo Vinci, Botre e Ruggieri (1995. A identificação e quantificação dos tocoferóis e do ácido ascórbico foi realizada em um sistema de cromatografia liquída de alta eficiência (CLAE, utilizando detector de fluorescência para os tocoferóis (excitação em 290 nm e emissão em 330 nm e detector de UV-Visível para o ácido ascórbico (254 nm. A amora-preta cv. Tupy apresentou maior teor de tocoferóis (8,251 µg.g-1 de fruta quando comparado ao conteúdo das demais frutas. Na pêra e nos pêssegos cv. Sensação e cv. Granada não identificou-se a presença de tocoferóis. As concentrações de ácido ascórbico variaram de 9,291 mg.g-1 para o physalis à 0,013 mg.g-1 para o jambolão. Conclui-se que as frutas são boas fontes destes compostos bioativos.

  9. Inhibition of lipid peroxidation by ellagic acid

    Energy Technology Data Exchange (ETDEWEB)

    Osawa, T.; Ide, A.; Su, J.D.; Namiki, M.

    Ellagic acid, a common plant phenol, was found to be an effective inhibitor of in vitro lipid peroxidation by the erythrocyte ghost and microsome test systems. The structure-activity relationship of ellagic acid and two of its derivatives has been carried out, and it was suggested that ellagic acid was the most potent inhibitor of the perferryl-dependent initiation step of NADPH-dependent microsomal lipid peroxidation. Ellagic acid was strongly inhibited lipid peroxidation induced by Adriamycin, but the two ellagic acid derivatives were much less effective. This difference was true of all NADPH-dependent microsomal lipid peroxidations.

  10. Rapid and specific spectrophotometric and RP-HPLC methods for the determination of ascorbic acid in fruits juices and in human plasma

    International Nuclear Information System (INIS)

    Ascorbic acid (AA) is one of the most important water soluble vitamin in the human diet, present naturally in a wide range of foods, especially fruits and vegetables. The objective of this study was to develop a rapid, sensitive and specific method for the determination of ascorbic acid (vitamin C) from a variety of sources like fresh fruits or from human plasma using spectrophotometric technique or by RP-HPLC. Initially, estimation of vitamin C was carried out spectrophotometrically as UV spectroscopy is a trusted technique to monitor small quantities of drugs and vitamins. The assay was linear over the concentration range of 0.05-100 mi cro g/mL/sup -I/. In the second procedure, we attempted to separate and quantitate ascorbic acid from fruit juices as well as from human plasma by RP-HPLC with UV detection. This has been possible because of the diversity of columns and conditions of analysis available. Chromatographic separation was successfully achieved on a pre-packed Kromasil 100, C/sub 18/ (5 macro m 25 x 0.46) column using acetonitrile water (60:40; v/v) as mobile phase at a flow rate of 0.75 mL/sup -min/ and effluent monitored at 265 nm. The assay was also linear over the concentration range of 0.05-100 micro g/mL/sub -1/, with recovery ranging from 99.0-100.0 % and intra and inter day CV <3 % when applied to the analysis of ascorbic acid from fruit juice available in Pakistan at the time of study Grape fruit, malta, mosami, sweetlemon, fruiter, lemon, lime, custard apple, orange, lemon, guava and papaya juice were found to be very rich in as ascorbic acid, while chikoo, pear, apricot, peach, carrot and some other fruits were found to be poor sources of ascorbic acid. (author)

  11. Effect of gamma irradiation in presence of ascorbic acid on microbial composition and TBARS concentration of ground beef coated with an edible active coating

    International Nuclear Information System (INIS)

    The present study was conducted to evaluate the combined effect of gamma irradiation in presence of ascorbic acid on the microbiological characteristics and thiobarbituric acid-reactive substances (TBARS) concentration of ground beef coated with an edible coating, crosslinked by gamma irradiation. The medium fat ground beef patties (23% fat ) were divided into two separate treatment groups: (i) control (ground beef without additive), (ii) ground beef with 0.5% (w/w) ascorbic acid. Meat samples were irradiated at doses of 0, 1, 2, and 3 kGy and stored at 4±2 deg. C. The content of TBARS was evaluated. After 7 days of storage, Enterobacteriaceae, presumptive Staphylococcus aureus, presumptive Pseudomonas spp., Brochothrix thermosphacta and lactic acid bacteria were enumerated. Results showed that lactic acid bacteria and Br. thermosphacta were more resistant to irradiation than Enterobacteriaceae and Pseudomonas. The content in TBARS was stabilized during post-irradiation storage for samples containing ascorbic acid. Shelf life extension periods estimated on the basis of a limit level of 6 log CFU/g for APCs were 4, 7, and 10 days for samples irradiated at 1, 2, and 3 kGy, respectively. However, the incorporation of ascorbic acid in ground beef did not improve significantly (p>0.05) the inhibitory effect of gamma irradiation

  12. Effect of gamma irradiation in presence of ascorbic acid on microbial composition and TBARS concentration of ground beef coated with an edible active coating

    Energy Technology Data Exchange (ETDEWEB)

    Lacroix, M. E-mail: monique.lacroix@inrs-iaf.uquebec.ca; Ouattara, B.; Saucier, L.; Giroux, M.; Smoragiewicz, W

    2004-10-01

    The present study was conducted to evaluate the combined effect of gamma irradiation in presence of ascorbic acid on the microbiological characteristics and thiobarbituric acid-reactive substances (TBARS) concentration of ground beef coated with an edible coating, crosslinked by gamma irradiation. The medium fat ground beef patties (23% fat ) were divided into two separate treatment groups: (i) control (ground beef without additive), (ii) ground beef with 0.5% (w/w) ascorbic acid. Meat samples were irradiated at doses of 0, 1, 2, and 3 kGy and stored at 4{+-}2 deg. C. The content of TBARS was evaluated. After 7 days of storage, Enterobacteriaceae, presumptive Staphylococcus aureus, presumptive Pseudomonas spp., Brochothrix thermosphacta and lactic acid bacteria were enumerated. Results showed that lactic acid bacteria and Br. thermosphacta were more resistant to irradiation than Enterobacteriaceae and Pseudomonas. The content in TBARS was stabilized during post-irradiation storage for samples containing ascorbic acid. Shelf life extension periods estimated on the basis of a limit level of 6 log CFU/g for APCs were 4, 7, and 10 days for samples irradiated at 1, 2, and 3 kGy, respectively. However, the incorporation of ascorbic acid in ground beef did not improve significantly (p>0.05) the inhibitory effect of gamma irradiation.

  13. The characterization of the ascorbic acid-mediated alpha-amidation of alpha-melanotropin in cultured intermediate pituitary lobe cells.

    Science.gov (United States)

    Glembotski, C C

    1986-04-01

    Previous studies have shown that cultured rat intermediate pituitary lobe cells lose the ability to form ACTH-(1-13)NH2-related molecules (alpha MSH) and instead produce ACTH-(1-14)-related peptides. In vitro studies have shown that peptidylglycine alpha-amidating monooxygenase the enzyme responsible for the conversion of ACTH-(1-14) to ACTH-(1-13)NH2, requires ascorbate, CuSO4, and molecular oxygen as cofactors. In the present study we have demonstrated that cultured intermediate pituitary lobe cells require long term supplementation of the medium with ascorbate for continued production of immunoactive alpha-amidated alpha MSH. When the relative quantities of alpha-amidated and COOH-terminally glycine-extended forms of alpha MSH were assessed in biosynthetic labeling experiments, it was shown that either L-ascorbate or an epimer of the vitamin, D-isoascorbate, was capable of supporting cellular alpha-amidation. However, the potency of isoascorbate was approximately 4- to 5-fold lower than that of ascorbate. The ascorbate-mediated reestablishment of alpha-amidation ability was shown to be dependent on the presence of sodium in the medium; at physiological levels of ascorbate (35 microM), the EC50 for sodium was about 40 mM. Time-course experiments indicated that the time of exposure of the cultured cells to ascorbate could be decreased to as little as 30 min. However, a total incubation time of 6 h was required after such an exposure to convert biosynthetically labeled ACTH-(1-14)-related peptides to labeled ACTH-(1-13)NH2-related peptides. The time course of the effects of ascorbic acid on the reestablishment of alpha-amidation, as well as the relative stereospecificity for L-ascorbic acid and the sodium requirement, are all consistent with the hypothesis that ascorbic acid must be transported into the intermediate pituitary lobe cells to participate in the peptidyl alpha-amidation reaction. Moreover, it is apparent that the length of time required to reestablish alpha-amidation ability (6 h) is a function of transport of the cofactor into the granules, the rate of the peptidylglycine alpha-amidating monooxygenase-catalyzed reaction, or both. PMID:3004917

  14. Improvement on the thermal stability and activity of plant cytosolic ascorbate peroxidase 1 by tailing hyper-acidic fusion partners.

    Science.gov (United States)

    Zhang, Mengru; Gong, Ming; Yang, Yumei; Li, Xujuan; Wang, Haibo; Zou, Zhurong

    2015-04-01

    Cytosolic ascorbate peroxidase 1 (APX1) plays a crucial role in regulating the level of plant cellular reactive oxygen species and its thermolability is proposed to cause plant heat-susceptibility. Herein, several hyper-acidic fusion partners, such as the C-terminal peptide tails, were evaluated for their effects on the thermal stability and activity of APX1 from Jatropha curcas and Arabidopsis. The hyper-acidic fusion partners efficiently improved the thermostability and prevented thermal inactivation of APX1 in both plant species with an elevated heat tolerance of at least 2 °C. These hyper-acidified thermostable APX1 fusion variants are of considerable biotechnological potential and can provide a new route to enhance the heat tolerance of plant species especially of inherent thermo-sensitivity. PMID:25515798

  15. Iterative Saturation Mutagenesis of ?6 Subsite Residues in Cyclodextrin Glycosyltransferase from Paenibacillus macerans To Improve Maltodextrin Specificity for 2-O-d-Glucopyranosyl-l-Ascorbic Acid Synthesis

    OpenAIRE

    Han, Ruizhi; Long LIU; Shin, Hyun-dong; Chen, Rachel R.; Li, Jianghua; Du, Guocheng; Chen, Jian

    2013-01-01

    2-O-d-Glucopyranosyl-l-ascorbic acid (AA-2G), a stable l-ascorbic acid derivative, is usually synthesized by cyclodextrin glycosyltransferase (CGTase), which contains nine substrate-binding subsites (from +2 to ?7). In this study, iterative saturation mutagenesis (ISM) was performed on the ?6 subsite residues (Y167, G179, G180, and N193) in the CGTase from Paenibacillus macerans to improve its specificity for maltodextrin, which is a cheap and easily soluble glycosyl donor for AA-2G synthesis...

  16. FORMULATION AND EVALUATION OF ASCORBIC ACID EXTENDED RELEASE HYDROPHYLLIC MATRIX TABLETS BY USING HYDROXYPROPYL METHYLCELLULOSE AND POLYETHYLENE OXIDE AS MATRIX FORMING POLYMERS

    OpenAIRE

    Aleksovski, Aleksandar; Spaseska Aleksovska, Emilija; Jaši?, Midhat

    2012-01-01

    Aim: Developing extended release matrix tablets containing 350 mg ascorbic acid and hydroxypropyl methylcellulose (HPMC) or polyethylene oxide (PEO) as hydrophilic polymer/s which control the rate and degree of drug release through 12 hour period. Materials and methods: Six batches of matrix tablets (P1, P2, P3, P4, P5, P6) were produced by direct compression. Ascorbic acid 97% was used as active compound. HPMC K4M, HPMC K15M, PEO 1105 and PEO 301 were used as hydrophilic polymers. Cellulo...

  17. Effects of ascorbic acid and glucose oxidase levels on the viability of probiotic bacteria and the physical and sensory characteristics in symbiotic ice-cream

    OpenAIRE

    M. B. Ak?n; F. Dasnik

    2015-01-01

    In this study, the effects of addition of different amounts of ascorbic acid and glucose oxidase on the properties of symbiotic ice cream were investigated. Ice-cream containing inulin (2 % (w/w)) was produced by mixing fortified milk fermented with probiotic strains with the ice-cream mixes containing different ascorbic acid and glucose oxidase concentrations (0.025, 0.05, 0.1 (w/w)). The cultures were grown (37 °C, 12 h) in UHT skimmed milk. The fermented milk was added to the ice-cream mix...

  18. Highly selective electrochemical sensor for ascorbic acid based on a novel hybrid graphene-copper phthalocyanine-polyaniline nanocomposites

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • A novel preparation method for nanocomposites, with CuPc immobilized on graphene in PANI matrix. • The Gr/CuPc/PANI enhanced selectivity and sensitivity of detecting AA due to graphene. • The constructed AA sensor shows excellent performances. - Abstract: In this work, we designed a novel electrochemical sensing platform based on graphene (Gr)/copper(II) phthalocyanine-tetrasulfonic acid tetrasodium salt (CuPc)/polyaniline(PANI) nanocomposites. The prepared composites were used to modify screen printed electrodes (SPE) for selective determination of ascorbic acid (AA) in presence of dopamine (DA) and uric acid (UA). Copper phthalocyanine was immobilized on graphene sheets by π-π interaction by electrolytical exfoliation and resulting CuPc/graphene was embedded in a PANI matrix to prevent leakage of Gr/CuPc from electrodes. The Gr/CuPc/PANI nanocomposites were characterized by scanning electron microscopy (SEM), UV-vis spectroscopy, cyclic voltammetry (CV) and amperometry. The prepared modified electrode presents good electrocatalytic properties, fast response time, high stability and reproducibility. The performance of the sensor exhibited a linear range from 5 × 10−7 to 1.2 × 10−5 M with low a limit of detection of 6.3 × 10−8 M (S/N = 3) and the sensitivity of the sensor was found to be 24.46 μA mM−1. Moreover, the nanocomposites show excellent selectivity and lower potential for the oxidation of ascorbic acid. The novel sensor successfully applied to determination of AA in real samples with satisfactory results. This can open up new opportunities for fast, simple and selective detection of AA and provide a promising platform for sensor or biosensor designs for AA detection

  19. Poly (3-(3-Pyridyl) Acrylic Acid) Modified Glassy Carbon Electrode for Simultaneous Determination of Dopamine, Ascorbic Acid and Uric Acid

    International Nuclear Information System (INIS)

    Trans-3-(3-pyridyl) acrylic acid (PAA) was deposited on glassy carbon electrode (GCE) by electro polymerization in pH 7.0 phosphate buffer solution (PBS). The poly (3-(3-pyridyl) acrylic acid) (PPAA) film modified glassy carbon electrode shows an excellent electrochemical response for dopamine (DA), ascorbic acid (AA) and uric acid (UA). The cyclic voltammetry oxidation peaks for DA and AA, DA and UA, AA and UA are separated by 150 mV, 130 mV and 280 mV, respectively. This permits the simultaneous determination of AA, DA and UA. The interference of AA with the determination of DA could be eliminated because of the electrostatic interaction between DA cations and the negatively charged PPAA film at pH 7.0. The anodic peak currents of DA, AA and UA increase linearly with concentration in the range of 1-40 ?mol L-1, 10-400 ?mol L-1 and 1.6-80 ?mol L-1, respectively, with a correlation coefficient (r) always higher than 0.998. The detection limit is 0.06 ?mol L-1, 0.8 ?mol L-1 and 1.1 ?mol L-1 for DA, AA and UA, respectively

  20. Cognitive deficits and decreased locomotor activity induced by single-walled carbon nanotubes and neuroprotective effects of ascorbic acid

    Directory of Open Access Journals (Sweden)

    Liu X

    2014-02-01

    Full Text Available Xudong Liu,1,* Yuchao Zhang,1,* Jinquan Li,1 Dong Wang,1 Yang Wu,1 Yan Li,2 Zhisong Lu,3 Samuel CT Yu,4 Rui Li,1 Xu Yang1 1Laboratory of Environmental Biomedicine, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Science, Central China Normal University, Wuhan, People's Republic of China; 2Chemical and Biomolecular Engineering Department, Hong Kong University of Science and Technology, Hong Kong Special Administrative Region; 3Institute for Clean Energy and Advanced Materials, Southwest University, Chongqing, People's Republic of China; 4Division of Environment, Hong Kong University of Science and Technology, Hong Kong Special Administrative Region *These authors contributed equally to this work Abstract: Single-walled carbon nanotubes (SWCNTs have shown increasing promise in the field of biomedicine, especially in applications related to the nervous system. However, there are limited studies available on the neurotoxicity of SWCNTs used in vivo. In this study, neurobehavioral changes caused by SWCNTs in mice and oxidative stress were investigated. The results of ethological analysis (Morris water maze and open-field test, brain histopathological examination, and assessments of oxidative stress (reactive oxygen species [ROS], malondialdehyde [MDA], and glutathione [GSH], inflammation (nuclear factor ?B, tumor necrosis factor a, interleukin-1?, and apoptosis (cysteine-aspartic acid protease 3 in brains showed that 6.25 and 12.50 mg/kg/day SWCNTs in mice could induce cognitive deficits and decreased locomotor activity, brain histopathological alterations, and increased levels of oxidative stress, inflammation, and apoptosis in mouse brains; however, 3.125 mg/kg/day SWCNTs had zero or minor adverse effects in mice, and these effects were blocked by concurrent administration of ascorbic acid. Down-regulation of oxidative stress, inflammation, and apoptosis were proposed to explain the neuroprotective effects of ascorbic acid. This work suggests SWCNTs could induce cognitive deficits and decreased locomotor activity, and provides a strategy to avoid the adverse effects. Keywords: behavioral changes, oxidative stress, inflammation, apoptosis

  1. ASCORBATE PEROXIDASE6 protects Arabidopsis desiccating and germinating seeds from stress and mediates cross talk between reactive oxygen species, abscisic acid, and auxin.

    Science.gov (United States)

    Chen, Changming; Letnik, Ilya; Hacham, Yael; Dobrev, Petre; Ben-Daniel, Bat-Hen; Vanková, Radomíra; Amir, Rachel; Miller, Gad

    2014-09-01

    A seed's ability to properly germinate largely depends on its oxidative poise. The level of reactive oxygen species (ROS) in Arabidopsis (Arabidopsis thaliana) is controlled by a large gene network, which includes the gene coding for the hydrogen peroxide-scavenging enzyme, cytosolic ASCORBATE PEROXIDASE6 (APX6), yet its specific function has remained unknown. In this study, we show that seeds lacking APX6 accumulate higher levels of ROS, exhibit increased oxidative damage, and display reduced germination on soil under control conditions and that these effects are further exacerbated under osmotic, salt, or heat stress. In addition, ripening APX6-deficient seeds exposed to heat stress displayed reduced germination vigor. This, together with the increased abundance of APX6 during late stages of maturation, indicates that APX6 activity is critical for the maturation-drying phase. Metabolic profiling revealed an altered activity of the tricarboxylic acid cycle, changes in amino acid levels, and elevated metabolism of abscisic acid (ABA) and auxin in drying apx6 mutant seeds. Further germination assays showed an impaired response of the apx6 mutants to ABA and to indole-3-acetic acid. Relative suppression of abscisic acid insensitive3 (ABI3) and ABI5 expression, two of the major ABA signaling downstream components controlling dormancy, suggested that an alternative signaling route inhibiting germination was activated. Thus, our study uncovered a new role for APX6, in protecting mature desiccating and germinating seeds from excessive oxidative damage, and suggested that APX6 modulate the ROS signal cross talk with hormone signals to properly execute the germination program in Arabidopsis. PMID:25049361

  2. Contenido de osmoprotectores, ácido ascórbico y ascorbato peroxidasa en hojas de frijol sometidas a estrés por sequía / Osmoprotectants content, ascorbic acid and ascorbate peroxidase on bean leaves under drought stress

    Scientific Electronic Library Online (English)

    Teresa Susana, Herrera Flores; Joaquín, Ortíz Cereceres; Adriana, Delgado Alvarado; Jorge Alberto, Acosta Galleros.

    2014-08-01

    Full Text Available La acumulación de osmoprotectores en plantas que se encuentran en condiciones de estrés por sequía, le permiten contrarrestar el efecto negativo que le provoca dichas condición ambiental. En el presente trabajo se estudió la respuesta bioquímica de plantas de frijol con base en la acumulación de car [...] bohidratos solubles, almidón, ácido ascórbico, así como la actividad de la enzima ascorbato peroxidasa, en las hojas simples y en las dos primeras hojas trifolioladas de la variedad resistente, Pinto Villa, y la susceptible a sequía Bayo Madero, ambas de raza Durango. Las plantas de ambas variedades se sometieron a tres tratamientos de humedad, riego, sequía y riego de recuperación. Con respecto a Bayo Madero, Pinto Villa mostró una mayor respuesta de tolerancia al estrés de humedad relacionada con: altas concentraciones de prolina, de ácido ascórbico y mayor actividad de la enzima ascorbato peroxidasa, ésta última en el tratamiento de sequía. En relación a la cantidad de carbohidratos solubles, Bayo Madero fue estadísticamente superior (p Abstract in english The accumulation of osmoprotectants in plants that are under stress from drought, allow you to offset the negative effect that causes these environmental conditions. In this study the biochemical response of bean plants based on the accumulation of soluble carbohydrates, starch, ascorbic acid, and t [...] he activity of ascorbate peroxidase enzyme, simple leaves and the first two leaves trifoliolate of studied resistant variety, Pinto Villa, and susceptible to drought Bayo Madero, both of Durango race. Plants from two varieties were subjected to three moisture treatments, irrigation and irrigation drought recovery. Regarding Bayo Madero, Pinto Villa showed increased stress tolerance response related humidity: high concentrations of proline, ascorbic acid, and increased activity of the peroxidase enzyme ascorbate, the latter in the drying treatment. In relation to the amount of soluble carbohydrates, Bayo Madero was statistically superior (p

  3. A gold electrode with a flower-like gold nanostructure for simultaneous determination of dopamine and ascorbic acid

    International Nuclear Information System (INIS)

    We have developed a facile method for the preparation of a gold electrode modified with a flower-like gold nanostructure using potentiostatic electrodeposition. Its formation, morphology, and electrochemical properties were studied by scanning electron microscopy and cyclic voltammetry. The resulting nanostructures possess rough and enlarged surface areas and enable fast electron transfer in the selective and sensitive detection of ascorbic acid (AA) and dopamine (DA) in phosphate-buffered saline without disturbance by common interferents. The differential pulse voltammetry anodic peak currents at approximately ?0.03 V and 0.16 V are strongly enhanced in the presence of AA and DA, respectively. The electrode responds linearly to AA in the concentration range from 60 ?M to 500 ?M, with a limit of detection at 10 ?M. The respective data for DA are 1 ?M to 150 ?M, and the limit of detection is 0.2 ?M. (author)

  4. Ascorbic acid for the healing of skin wounds in rats / Ácido ascórbico na cicatrização de feridas cutâneas em ratos

    Scientific Electronic Library Online (English)

    CC., Lima; APC., Pereira; JRF., Silva; LS., Oliveira; MCC., Resck; CO., Grechi; MTCP., Bernardes; FMP., Olímpio; AMM., Santos; EK., Incerpi; JAD., Garcia.

    2009-11-01

    Full Text Available FUNDAMENTOS: A cicatrização é um processo complexo que envolve eventos celulares e bioquímicos. Vários medicamentos têm sido empregados na tentativa de abreviar a cicatrização e evitar danos estéticos. OBJETIVO: verificar o efeito tópico do ácido ascórbico no processo de cicatrização de feridas cutâ [...] neas de ratos através da verificação do número de macrófagos, neovasos e fibroblastos presentes no período experimental; e analisar a espessura e a organização das fibras colágenas no tecido lesado. MÉTODOS: Foram utilizados Rattus norvegicus, machos, pesando 270 ± 30 g. Foi realizada incisão transversal na pele da região dorso-cervical de 15 mm de comprimento, após anestesia com Thionembutal. Os animais foram divididos em 2 grupos: grupo controle (GC, n = 12), feridas higienizadas diariamente com água e sabão; grupo tratado (GT, n = 12), feridas higienizadas e tratadas com creme de ácido ascórbico (10%). Os fragmentos para análise histológica foram coletados no 3º, 7º e 14º dia, e as lâminas coradas com hematoxilina-eosina e picrosírius red para análise morfológica. As imagens foram capturadas e analisadas por um sistema digitalizador. RESULTADOS: O ácido ascórbico atuou em todas as etapas da cicatrização, diminuindo o número de macrófagos, aumentando a proliferação dos fibroblastos e neovasos, e favorecendo a deposição de fibras colágenas mais espessas e organizadas nas feridas. CONCLUSÃO: O ácido ascórbico mostrou ter efeito antiinflamatório e cicatrizante, promovendo ambiente e condições favoráveis para a reparação tecidual, o que abreviou o tempo da cicatrização. Abstract in english BACKGROUND: Healing is a complex process that involves cellular and biochemical events. Several medicines have been used in order to shorten healing time and avoid aesthetic damage. OBJECTIVE: to verify the topical effect of ascorbic acid for the healing of rats' skin wounds through the number of ma [...] crophages, new vessels and fibroblast verifications in the experimental period; and analyse the thickness and the collagen fibre organization in the injured tissue. METHODS: Male Rattus norvegicus weighing 270 ± 30 g were used. After thionembutal anesthesia, 15 mm transversal incisions were made in the animals' cervical backs. They were divided into two groups: Control Group (CG, n = 12) - skin wound cleaned with water and soap daily; Treated Group (TG, n = 12) - skin wound cleaned daily and treated with ascorbic acid cream (10%). Samples of skin were collected on the 3rd, 7th and 14th days. The sections were stained with hematoxylin-eosin and picrosirius red for morphologic analysis. The images were obtained and analysed by a Digital Analyser System. RESULTS: The ascorbic acid acted on every stage of the healing process. It reduced the number of macrophages, increased the proliferation of fibroblasts and new vessels, and stimulated the synthesis of thicker and more organized collagen fibres in the wounds when compared to CG. CONCLUSION: Ascorbic acid was shown to have anti-inflammatory and healing effects, guaranteeing a suiTable environment and conditions for faster skin repair.

  5. Nitrate, ascorbic acid, mineral and antioxidant activities of Cosmos caudatus in response to organic and mineral-based fertilizer rates.

    Science.gov (United States)

    Hassan, Siti Aishah; Mijin, Salumiah; Yusoff, Umi Kalsom; Ding, Phebe; Wahab, Puteri Edaroyati Megat

    2012-01-01

    The source and quantity of nutrients available to plants can affect the quality of leafy herbs. A study was conducted to compare quality of Cosmos caudatus in response to rates of organic and mineral-based fertilizers. Organic based fertilizer GOBI (8% N:8% P?O?:8% K?O) and inorganic fertilizer (15% N, 15% P?O?, 15% K?O) were evaluated based on N element rates at 0, 30, 60, 90, 120 kg h?¹. Application of organic based fertilizer reduced nitrate, improved vitamin C, antioxidant activity as well as nitrogen and calcium nutrients content. Antioxidant activity and chlorophyll content were significantly higher with increased fertilizer application. Fertilization appeared to enhance vitamin C content, however for the maximum ascorbic acid content, regardless of fertilizer sources, plants did not require high amounts of fertilizer. PMID:22743588

  6. L-ascorbic acid losses in Kenyan vegetables during cooking as determined by high performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    N.M.N. Wekesa

    2001-06-01

    Full Text Available The loss of L-ascorbic acid (L-AA in 14 different cooked local vegetables found in Nairobi markets was determined by high performance liquid chromatography. The effect of quantity of water on the loss of L-AA during cooking was studied with cowpea leaves. It was found that more L-AA was lost when larger amount of water was used than when smaller amount was used. The effect of the sharpness of the knife on the loss of L-AA was studied with spinach. It was found that more loss of L-AA occurred when a blunt (edge thickness 0.08 cm knife was used for cutting the vegetables than when a sharp knife (edge thickness 0.04 cm was used during cooking. L-AA was also determined when vegetables were cooked in different size pieces (surface are >1 cm2

  7. An in vitro co-culture model of esophageal cells identifies ascorbic acid as a modulator of cell competition

    Directory of Open Access Journals (Sweden)

    Gardiner Kristin L

    2011-10-01

    Full Text Available Abstract Background The evolutionary dynamics between interacting heterogeneous cell types are fundamental properties of neoplastic progression but can be difficult to measure and quantify. Cancers are heterogeneous mixtures of mutant clones but the direct effect of interactions between these clones is rarely documented. The implicit goal of most preventive interventions is to bias competition in favor of normal cells over neoplastic cells. However, this is rarely explicitly tested. Here we have developed a cell culture competition model to allow for direct observation of the effect of chemopreventive or therapeutic agents on two interacting cell types. We have examined competition between normal and Barrett's esophagus cell lines, in the hopes of identifying a system that could screen for potential chemopreventive agents. Methods One fluorescently-labeled normal squamous esophageal cell line (EPC2-hTERT was grown in competition with one of four Barrett's esophagus cell lines (CP-A, CP-B, CP-C, CP-D under varying conditions and the outcome of competition measured over 14 days by flow cytometry. Results We demonstrate that ascorbic acid (vitamin C can help squamous cells outcompete Barrett's cells in this system. We are also able to show that ascorbic acid's boost to the relative fitness of squamous cells was increased in most cases by mimicking the pH conditions of gastrointestinal reflux in the lower esophagus. Conclusions This model is able to integrate differential fitness effects on various cell types, allowing us to simultaneously capture effects on interacting cell types without having to perform separate experiments. This model system may be used to screen for new classes of cancer prevention agents designed to modulate the competition between normal and neoplastic cells.

  8. Protective effects of alpha-hederin, chlorophyllin and ascorbic acid towards the induction of micronuclei by doxorubicin in cultured human lymphocytes.

    Science.gov (United States)

    Amara-Mokrane, Y A; Lehucher-Michel, M P; Balansard, G; Duménil, G; Botta, A

    1996-03-01

    The influence of alpha-hederin (a saponin isolated from Hedera helix), chlorophyllin, the sodium-copper salt of chlorophyll, and ascorbic acid (vitamin C) on the direct clastogenicity of doxorubicin (Adriamycin) was investigated in vitro in human lymphocytes for the induction of micronuclei. In order to determine a possible mechanism of action responsible for the antimutagenic activity, treatments were performed for the three substances at different times of the culture (pre-treatment, simultaneous and post-treatment). Alpha-hederin (1.3 x 10(-2), 0.13, 1.3 and 13 nmol/ml) and chlorophyllin (0.14, 1.4 and 14 nmol/ml) were found to exert an antimutagenic effect against the clastogenicity of doxorubicin (1.5 x 10(-2) nmol/ml) in all treatments at all concentrations. Ascorbic acid (10 nmol/ml) was effective in reducing the micronucleus levels only in the simultaneous treatment, when it was previously incubated with doxorubicin for 2 h at 37 degrees C before being introduced into the culture. Our results suggested a desmutagenic effect for alpha-hederin, chlorophyllin and ascorbic acid. Chlorophyllin acted also through a bio-antimutagenic mechanism and alpha-hederin seemed to induce metabolic enzymes, which inactivated doxorubicin. Preliminary studies showed that the effective antimutagenic concentrations of alpha-hederin, chlorophyllin and ascorbic acid had no clastogenic or aneugenic effects in human lymphocytes. No cytotoxicity was observed for the three antimutagenic agents either. PMID:8671733

  9. Quantification and histochemical localization of ascorbic acid in 'Delicious', 'Golden Delicious', and 'Fuji' apple fruit during on-tree development and cold storage

    Science.gov (United States)

    Apple fruit are subject to multiple stressors during pre- and post-harvest development. Stress-induced reactive oxygen species (ROS) can be detrimental to the fruit, and ascorbic acid (AsA) is involved in many of the antioxidant pathways that detoxify ROS. An inclusive study to characterize AsA dy...

  10. The novel C-5 aryl, alkenyl, and alkynyl substituted uracil derivatives of L-ascorbic acid: synthesis, cytostatic, and antiviral activity evaluations.

    Science.gov (United States)

    Gazivoda, Tatjana; Rai?-Mali?, Silvana; Marjanovi?, Marko; Kralj, Marijeta; Paveli?, Kresimir; Balzarini, Jan; De Clercq, Erik; Mintas, Mladen

    2007-01-15

    The novel C-5 substituted uracil derivatives of l-ascorbic acid were synthesized by coupling of 5-iodouracil-4,5-didehydro-5,6-dideoxy-l-ascorbic acid with unsaturated stannanes under Stille reaction conditions. The new compounds were evaluated for their antitumoral and antiviral activities. Among all compounds evaluated the 5-propynyl substituted uracil derivative of l-ascorbic acid (7) exhibited the most pronounced cytostatic activities against all examined tumor cell lines (IC(50): 0.2-0.78 microM). However, this compound was also cytotoxic to human normal fibroblasts WI 38. The 5-(phenylethynyl)uracil-2,3-di-O-benzylated l-ascorbic acid derivative (4) exhibited an albeit slight (IC(50): 55-108 microM), but selective inhibitory effect toward all tumor cell lines except for cervical carcinoma (HeLa), pancreatic carcinoma (MiaPaCa-2), laryngeal carcinoma (Hep-2), and colon carcinoma (SW 620), and no cytotoxicity to normal human fibroblast (WI 38). Compound 7 showed some, not highly specific, inhibitory potential against vesicular stomatitis virus, Coxsackie B4 virus, and Sindbis viruses (EC(50): 1.6 microM). PMID:17092728

  11. Development of HPLC and UV spectrophotometric methods for the determination of ascorbic acid using hydroxypropyl-?-cyclodextrin and triethanolamine as photostabilizing agents

    International Nuclear Information System (INIS)

    In this study, the effect of complex formation with triethanolamine (TEA) alone and in combination with hydroxypropyl-?-cyclodextrin (HP-?-CD) on the photostability of ascorbic acid was evaluated for exposure to artificial and diffuse daylight. The first-order rate constants for the photodegradation reactions were determined. The data obtained showed that these complexes strongly reduced the photodegradation process with an 11- and 35-fold increase in the photostability of ascorbic acid, depending of the ligand concentration and the irradiation source. The multicomponent complex gave a significantly better stabilization for exposure to light than TEA alone. Due to the fact that the complexation extended the exposure of ascorbic acid to light (without molecular changes), UV spectrophotometric and reversed phase high performance liquid chromatographic (HPLC) methods were developed for the quantitative determination of the vitamin in pure form and in pharmaceutical preparations. These methods were statistically validated, all the validation parameters were found to be within the acceptance range. These results demonstrate that the proposed methods are suitable for the quality control of ascorbic acid, providing simple, rapid, precise, accurate and convenient approaches for routine analysis of bulk drug and pharmaceutical formulations.

  12. Stimulative Effects of Ascorbic Acid, Thiamin or Pyridoxine on Vicia faba Growth and Some Related Metabolic Activities

    OpenAIRE

    A. M. Hamada; E. M. Khulaef

    2000-01-01

    Soaking of bean seeds in 100 ppm ascorbic acid, thiamin or pyridoxine induced a stimulation effect on germination. Also, soaking of seeds or spraying of bean seedlings (25 day old) with 100 ppm of each of these vitamins, stimulated fresh and dry weight, biosynthesis of photosynthetic pigment fractions and net photosynthetic rate. However, these treatments did not induce a considerable change in dark respiration.

  13. Efficacy of morning-only 4 liter sulfa free polyethylene glycol vs 2 liter polyethylene glycol with ascorbic acid for afternoon colonoscopy

    OpenAIRE

    Rivas, John M; Perez, Alejandro; Hernandez, Marlow; Schneider, Alison; Castro, Fernando J

    2014-01-01

    AIM: To compare the bowel cleansing efficacy of same day ingestion of 4-L sulfa-free polyethylene glycol (4-L SF-PEG) vs 2-L polyethylene glycol solution with ascorbic acid (2-L PEG + Asc) in patients undergoing afternoon colonoscopy.

  14. [The anticlastogenic effect of ascorbic acid in relation to the damages induced in human lymphocytes by the photomutagenic action of 8-methoxypsoralen and by ammonium molybdate].

    Science.gov (United States)

    Makedonov, G P; Bobyleva, L A; Chekova, V V; Zasukhina, G D

    1995-01-01

    In experiments with cultured human lymphocytes anticlastogenic effect of ascorbic acid (AA) with respect to photomutagenic action of 8-methoxypsoralen (8-MOP) and ammonium molibdenate (Mo) was studied. It was found that AA effectively protected from mutagenic action of Mo. Effective protection of cells from 8-MOP monoadducts and DNA interstrand links was also observed. PMID:7489108

  15. ASCORBIC ACID TREATMENT TO REDUCE RESIDUAL HALOGEN-BASED OXIDANTS PRIOR TO THE DETERMINATION OF HALOGENATED DISINFECTION BYPRODUCTS IN POTABLE WATER

    Science.gov (United States)

    Treatment of potable water samples with ascorbic acid has been investigated as a means for reducing residual halogen-based oxidants (disinfectants)i.e., HOCl, Cl2, Brw and BrCl, prior to determination of EPA Method 551.1A and 551.1B analytes. These disinfection byproducts include...

  16. Chemical repair of base lesions, AP-sites, and strand breaks on plasmid DNA in dilute aqueous solution by ascorbic acid.

    Science.gov (United States)

    Hata, Kuniki; Urushibara, Ayumi; Yamashita, Shinichi; Shikazono, Naoya; Yokoya, Akinari; Katsumura, Yosuke

    2013-05-01

    We quantified the damage yields produced in plasmid DNA by ?-irradiation in the presence of low concentrations (10-100 ?M) of ascorbic acid, which is a major antioxidant in living systems, to clarify whether it chemically repairs radiation damage in DNA. The yield of DNA single strand breaks induced by irradiation was analyzed with agarose gel electrophoresis as conformational changes in closed circular plasmids. Base lesions and abasic sites were also observed as additional conformational changes by treating irradiated samples with glycosylase proteins. By comparing the suppression efficiencies to the induction of each DNA lesion, in addition to scavenging of the OH radicals derived from water radiolysis, it was found that ascorbic acid promotes the chemical repair of precursors of AP-sites and base lesions more effectively than those of single strand breaks. We estimated the efficiency of the chemical repair of each lesion using a kinetic model. Approximately 50-60% of base lesions and AP-sites were repaired by 10 ?M ascorbic acid, although strand breaks were largely unrepaired by ascorbic acid at low concentrations. The methods in this study will provide a route to understanding the mechanistic aspects of antioxidant activity in living systems. PMID:23567970

  17. Development of HPLC and UV spectrophotometric methods for the determination of ascorbic acid using hydroxypropyl-{beta}-cyclodextrin and triethanolamine as photostabilizing agents

    Energy Technology Data Exchange (ETDEWEB)

    Garnero, Claudia [Departamento de Farmacia, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina); Longhi, Marcela, E-mail: mrlcor@fcq.unc.edu.ar [Departamento de Farmacia, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina)

    2010-02-05

    In this study, the effect of complex formation with triethanolamine (TEA) alone and in combination with hydroxypropyl-{beta}-cyclodextrin (HP-{beta}-CD) on the photostability of ascorbic acid was evaluated for exposure to artificial and diffuse daylight. The first-order rate constants for the photodegradation reactions were determined. The data obtained showed that these complexes strongly reduced the photodegradation process with an 11- and 35-fold increase in the photostability of ascorbic acid, depending of the ligand concentration and the irradiation source. The multicomponent complex gave a significantly better stabilization for exposure to light than TEA alone. Due to the fact that the complexation extended the exposure of ascorbic acid to light (without molecular changes), UV spectrophotometric and reversed phase high performance liquid chromatographic (HPLC) methods were developed for the quantitative determination of the vitamin in pure form and in pharmaceutical preparations. These methods were statistically validated, all the validation parameters were found to be within the acceptance range. These results demonstrate that the proposed methods are suitable for the quality control of ascorbic acid, providing simple, rapid, precise, accurate and convenient approaches for routine analysis of bulk drug and pharmaceutical formulations.

  18. Electrochemical Deposition and Characterization of Poly(3,4-ethylene dioxythiophene), Poly(aniline) and their Copolymer onto Glassy Carbon Electrodes for Potential Use in Ascorbic Acid Oxidation

    Scientific Electronic Library Online (English)

    G.M., El-Enany; M.A., Ghanem; M.A. Abd, El-Ghaffar.

    Full Text Available Poly(3,4-ethylene dioxythiophene) (PEDOT), poly(aniline) (PANI) and their copolymer (PEDOT-PANI) were electrodeposited onto a glassy carbon electrode. The electrodeposition was performed using cyclic voltammetry from acidic solution containing appropriate monomer concentrations and sodium dodecyl su [...] lphate (SDS) as a wetting agent. The resulting polymer films were characterised using cyclic voltammetry in acidic and neutral phosphate buffer solutions and IR spectroscopy. The specific capacitance of the PEDOT-PANI co-polymer reaches up to 260 F g?1 and had good stability during cycling in mineral acid solution. IR spectroscopy confirms the formation of PEDOT-PANI copolymer. The polymers showed an electrochemical activity towards ascorbic acid oxidation. The oxidation current was linearly dependant up to 20 mM ascorbic acid concentration and the PEDOT activity was much higher than that for PANI and PEDOT-PANI copolymer.

  19. Susceptibility of Propionibacterium acnes isolated from patients with acne vulgaris to zinc ascorbate and antibiotics

    Directory of Open Access Journals (Sweden)

    Iinuma K

    2011-10-01

    Full Text Available Katsuhiro Iinuma1, Norihisa Noguchi2, Hidemasa Nakaminami2, Masanori Sasatsu2, Setsuko Nishijima3, Isami Tsuboi1 1BML General Laboratory, Matoba, Kawagoe, Saitama, 2Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo, 3Department of Dermatology, Nishijima Skin Clinic, Osaka, Japan Purpose: The in vitro antimicrobial activity of ascorbic acid derivatives against Propionibacterium acnes was tested either alone or in combination with a variety of antimicrobial agents, and their fractional inhibitory concentration index was determined using checkerboard tests. The antimicrobial effectiveness of zinc ascorbate in the treatment of acne vulgaris, either alone or in combination with antibiotics such as clindamycin that are commonly used in Japan for the treatment of acne vulgaris, was therefore examined. Materials and methods: The antimicrobial susceptibility of 41 strains of clindamycin-sensitive and/or clindamycin-resistant P. acnes isolated from acne vulgaris patients was tested, in comparison with a type strain of P. acnes. Results: Zinc ascorbate showed antimicrobial activity against a type strain of P. acnes and its concentration (0.064% was sufficiently lower than the normal dose (5% of other ascorbic acid derivatives. Combinations of zinc ascorbate with clindamycin, erythromycin, and chloramphenicol showed an additive effect, and zinc ascorbate alone effectively inhibited the growth of all P. acnes including clindamycin-resistant strains. Conclusion: The results provide novel evidence that the combination of zinc ascorbate and clindamycin is effective for acne vulgaris treatment. Keywords: antimicrobial susceptibility, ascorbic acid derivatives, combination therapy, checkerboard test

  20. Uso do ácido ascórbico no controle do escurecimento do pericarpo de lichia Use of ascorbic acid in the control of browning in the pericarp of lychees

    Directory of Open Access Journals (Sweden)

    Danieele Fabíola Pereira da Silva

    2010-06-01

    Full Text Available Um dos maiores problemas na pós-colheita da lichia é o escurecimento do pericarpo, o qual tem sido atribuído à degradação da antocianina. O objetivo do trabalho foi avaliar o efeito de diferentes doses de ácido ascórbico na prevenção do escurecimento do pericarpo e na manutenção da qualidade pós-colheita de lichia. Frutos de lichieira 'Bengal' com o pericarpo completamente vermelho foram imersos em solução com diferentes doses de ácido ascórbico (0; 5; 10; 15 e 30 mM, por 5 minutos. Após secagem à temperatura ambiente, foram acondicionados em bandejas de poliestireno, armazenados em câmara fria a 5 ± 1,2°C e 90 ± 5% de UR e avaliados a cada 4 dias, durante 12 dias. Observou-se que a perda de massa fresca foi maior nos frutos não tratados com ácido ascórbico. Independentemente da dose, o ácido ascórbico teve pouco efeito na retenção da cor vermelha do pericarpo de lichia. A atividade das enzimas polifenoloxidase e peroxidase no pericarpo foi maior com as menores doses de ácido ascórbico (0; 5 e 10 mM, entretanto observou-se escurecimento a partir do quarto dia no pericarpo dos frutos tratados com este ácido. O ácido ascórbico também não foi eficiente na manutenção da qualidade interna dos frutos.One of the biggest problems in postharvest of lychees is the pericarp browning, which has been attributed to anthocyanins degradation. The purpose of this work was to evaluate the effect of different doses of ascorbic acid to prevent pericarp browning and on the maintenance of postharvest quality of lychees. Fruits of 'Bengal' lychee with completely red pericarp were immersed in solution with different doses of ascorbic acid (0, 5, 10, 15 and 30 mM for 5 minutes. After dried, the fruits were packed in polystyrene trays, stored in cold chamber at 5 ± 1,2°C e 90 ± 5% de RH and evaluated every other 4 days for 12 days. It was observed that the loss of fresh weight was higher in non-treated with ascorbic acid fruits. Independently of the dose, the ascorbic acid had little effect on the retention of the red color of the lychee pericarp. The polyphenoloxidase and peroxidase activities in the lychee pericarp was increased with lower doses of ascorbic acid (0, 5 and 10 mM, however, there was pericarp browning after the fourth day in the fruits of all treatments in ascorbic acid. Ascorbic acid was not efficient in maintaining the internal quality of fruit.

  1. Uso do ácido ascórbico no controle do escurecimento do pericarpo de lichia / Use of ascorbic acid in the control of browning in the pericarp of lychees

    Scientific Electronic Library Online (English)

    Danieele Fabíola Pereira da, Silva; Elaine Cristina, Cabrini; Robson Ribeiro, Alves; Luiz Carlos Chamhum, Salomão.

    2010-06-01

    Full Text Available Um dos maiores problemas na pós-colheita da lichia é o escurecimento do pericarpo, o qual tem sido atribuído à degradação da antocianina. O objetivo do trabalho foi avaliar o efeito de diferentes doses de ácido ascórbico na prevenção do escurecimento do pericarpo e na manutenção da qualidade pós-col [...] heita de lichia. Frutos de lichieira 'Bengal' com o pericarpo completamente vermelho foram imersos em solução com diferentes doses de ácido ascórbico (0; 5; 10; 15 e 30 mM), por 5 minutos. Após secagem à temperatura ambiente, foram acondicionados em bandejas de poliestireno, armazenados em câmara fria a 5 ± 1,2°C e 90 ± 5% de UR e avaliados a cada 4 dias, durante 12 dias. Observou-se que a perda de massa fresca foi maior nos frutos não tratados com ácido ascórbico. Independentemente da dose, o ácido ascórbico teve pouco efeito na retenção da cor vermelha do pericarpo de lichia. A atividade das enzimas polifenoloxidase e peroxidase no pericarpo foi maior com as menores doses de ácido ascórbico (0; 5 e 10 mM), entretanto observou-se escurecimento a partir do quarto dia no pericarpo dos frutos tratados com este ácido. O ácido ascórbico também não foi eficiente na manutenção da qualidade interna dos frutos. Abstract in english One of the biggest problems in postharvest of lychees is the pericarp browning, which has been attributed to anthocyanins degradation. The purpose of this work was to evaluate the effect of different doses of ascorbic acid to prevent pericarp browning and on the maintenance of postharvest quality of [...] lychees. Fruits of 'Bengal' lychee with completely red pericarp were immersed in solution with different doses of ascorbic acid (0, 5, 10, 15 and 30 mM) for 5 minutes. After dried, the fruits were packed in polystyrene trays, stored in cold chamber at 5 ± 1,2°C e 90 ± 5% de RH and evaluated every other 4 days for 12 days. It was observed that the loss of fresh weight was higher in non-treated with ascorbic acid fruits. Independently of the dose, the ascorbic acid had little effect on the retention of the red color of the lychee pericarp. The polyphenoloxidase and peroxidase activities in the lychee pericarp was increased with lower doses of ascorbic acid (0, 5 and 10 mM), however, there was pericarp browning after the fourth day in the fruits of all treatments in ascorbic acid. Ascorbic acid was not efficient in maintaining the internal quality of fruit.

  2. Electrocatalytic oxidation and voltammetric determination of ciprofloxacin employing poly(alizarin red)/graphene composite film in the presence of ascorbic acid, uric acid and dopamine

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xin; Wei, Youli; Ding, Yaping, E-mail: wdingyp@sina.com

    2014-07-04

    Graphical abstract: An electrochemical sensor based on PAR/EGR/GCE via a cooperation of the potentiostatic technique and cyclic voltammetry was first fabricated for the determination of CPFX with satisfied detecting result of real samples. - Highlights: • PAR/EGR composite film was prepared for the first time. • The sensor can be applied to determinate CPFX in the presence of AA, UA and DA. • The sensor indicated the feasibility in drug samples and biological media. - Abstract: A glassy carbon electrode modified with poly(alizarin red)/electrodeposited graphene (PAR/EGR) composite film was prepared and applied to detect ciprofloxacin (CPFX) in the presence of ascorbic, uric acid and dopamine. The morphology and interface property of PAR/EGR films were examined by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The electrocatalytic oxidation of CPFX on AR/EGR was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The linearity ranged from 4 × 10{sup ?8} to 1.2 × 10{sup ?4} M with a detection limit (S/N = 3) of 0.01 ?M. The modified electrode could be applied to the individual determination of CPFX as well as the simultaneous determination of CPFX, ascorbic acid, uric acid and dopamine. This method proved to be a simple, selective and rapid way to determine CPFX in pharmaceutical preparation and biological media.

  3. Electrocatalytic oxidation and voltammetric determination of ciprofloxacin employing poly(alizarin red)/graphene composite film in the presence of ascorbic acid, uric acid and dopamine

    International Nuclear Information System (INIS)

    Graphical abstract: An electrochemical sensor based on PAR/EGR/GCE via a cooperation of the potentiostatic technique and cyclic voltammetry was first fabricated for the determination of CPFX with satisfied detecting result of real samples. - Highlights: • PAR/EGR composite film was prepared for the first time. • The sensor can be applied to determinate CPFX in the presence of AA, UA and DA. • The sensor indicated the feasibility in drug samples and biological media. - Abstract: A glassy carbon electrode modified with poly(alizarin red)/electrodeposited graphene (PAR/EGR) composite film was prepared and applied to detect ciprofloxacin (CPFX) in the presence of ascorbic, uric acid and dopamine. The morphology and interface property of PAR/EGR films were examined by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The electrocatalytic oxidation of CPFX on AR/EGR was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The linearity ranged from 4 × 10?8 to 1.2 × 10?4 M with a detection limit (S/N = 3) of 0.01 ?M. The modified electrode could be applied to the individual determination of CPFX as well as the simultaneous determination of CPFX, ascorbic acid, uric acid and dopamine. This method proved to be a simple, selective and rapid way to determine CPFX in pharmaceutical preparation and biological media

  4. Understanding biocatalyst inhibition by carboxylic acids

    Directory of Open Access Journals (Sweden)

    LauraRJarboe

    2013-09-01

    Full Text Available Carboxylic acids are an attractive biorenewable chemical in terms of their flexibility and usage as precursors for a variety of industrial chemicals. It has been demonstrated that such carboxylic acids can be fermentatively produced using engineered microbes, such as Escherichia coli and Saccharomyces cerevisiae. However, like many other attractive biorenewable fuels and chemicals, carboxylic acids become inhibitory to these microbes at concentrations below the desired yield and titer. In fact, their potency as microbial inhibitors is highlighted by the fact that many of these carboxylic acids are routinely used as food preservatives. This review highlights the current knowledge regarding the impact that saturated, straight-chain carboxylic acids, such as hexanoic, octanoic, decanoic and lauric acids can have on E. coli and S. cerevisiae, with the goal of identifying metabolic engineering strategies to increase robustness. Key effects of these carboxylic acids include damage to the cell membrane and a decrease of the microbial internal pH. Certain changes in cell membrane properties, such as composition, fluidity, integrity and hydrophobicity, and intracellular pH are often associated with increased tolerance. The availability of appropriate exporters, such as Pdr12, can also increase tolerance. The effect on metabolic processes, such as maintaining appropriate respiratory function, regulation of Lrp activity and inhibition of production of key metabolites such as methionine, are also considered. Understanding the mechanisms of biocatalyst inhibition by these desirable products can aid in the engineering of robust strains with improved industrial performance.

  5. THE EFFECT OF ASCORBIC ACID ON PATHOHISTOLOGICAL TUMOR CHARACTERISTICS AND PHENOTYPE CHARACTERISTICS OF LYMPHOCYTES DURING THE DEVELOPMENT OF EXPERIMENTAL MAMMARY CARCINOMA IN MICE

    Directory of Open Access Journals (Sweden)

    Voja Pavlovic

    2005-04-01

    Full Text Available TIn our previous study we demonstrated that high doses of ascorbic acid prolonged the survival of mice with experimental mammary carcinoma. In this work we studied, ussing the same model, pathohistological characteristics of the tumor and phenotypic changes of lymphocyte subsets in the spleen. Experiments were performed on CBA/H mice. The growh of experimental tumor was induced by injection of mammary adenocarcinoma cells intramuscularly at the femoral region of mice. The animals were divided into control group and three experimental groups (I, II and III. Mice from experimental groups were treated peroraly with 10, 100 and 1000 mg/kg body mass (b.m. of ascorbic acid, respectively, whereas control mice received physiological saline. Mice were sacrified after 7, 14 and 21 days from the beginning of the experiment. Total tumor mass and its pathohistological characteristics, spleen mass and cellularity as well as relative and total numbers of T cells, B cells and T cell subsets (CD4+ and CD8+ in the spleen, were analyzed. High doses of ascorbic acid decreased tumor mass, stimulated proliferation of fibroblasts and formation of capsula arround the tumor, induced tumor necrosis and increased the number of tumor infiltrating lymphocytes. Changes of lymphocyte subsets and their numbers varied depending on the applied dose of ascorbic acid and the time elapsed following tumor induction. The most prominent changes, manifested by an increase in the number of CD4+ T cells were observed on the 14th day in II experimental group. Our results suggest that the beneficial effect of ascorbic acid on experimental tumorogenesis in our model was the consequence of its influence on the tumor and on the immune system.

  6. Effects of L- and iso-ascorbic acid on meat protein hydrolyzing activity of four commercial plant and three microbial protease preparations.

    Science.gov (United States)

    Ha, Minh; Bekhit, Alaa El-Din; Carne, Alan

    2014-04-15

    The present study investigated the effects of both l- and iso-ascorbic acid (AA) on the activity of four plant proteases (papain, bromelain, actinidin and zingibain) and three microbial proteases (Bacterial Protease G, Fungal 31,000 and Fungal 60,000) preparations using fluorescent-labelled casein, meat myofibrillar and connective tissue extracts to explore their effects on meat structure components upon treatment with individual proteases. While l-AA in the range 0.8-3.2mM inhibited the activity of papain, bromelain and zingibain, iso-AA acted as an inhibitor of papain but as an activator of zingibain and had no significant effect on bromelain. Both AA isoforms acted as an activator of the actinidin protease and the concentration of AA isoforms appeared to affect the level of activation of the protease. The effect of the two AA isoforms on collagen and myofibrillar protein hydrolyzing activity varied depending on the concentration of the two AA isoforms. The results indicate the ability to up and down regulate the activity of the investigated proteases by using an appropriate concentration of the AA isoform. PMID:24295669

  7. The non-oxidative degradation of ascorbic acid at physiological conditions.

    Science.gov (United States)

    Simpson, G L; Ortwerth, B J

    2000-04-15

    The degradation of L-ascorbate (AsA) and its primary oxidation products, L-dehydroascorbate (DHA) and 2,3-L-diketogulonate (2, 3-DKG) were studied under physiological conditions. Analysis determined that L-erythrulose (ERU) and oxalate were the primary degradation products of ASA regardless of which compound was used as the starting material. The identification of ERU was determined by proton decoupled (13)C-nuclear magnetic resonance spectroscopy, and was quantified by high performance liquid chromatography, and enzymatic analysis. The molar yield of ERU from 2,3-DKG at pH 7.0 37 degrees C and limiting O(2)97%. This novel ketose product of AsA degradation, was additionally qualitatively identified by gas-liquid chromatography, and by thin layer chromatography. ERU is an extremely reactive ketose, which rapidly glycates and crosslinks proteins, and therefore may mediate the AsA-dependent modification of protein (ascorbylation) seen in vitro, and also proposed to occur in vivo in human lens during diabetic and age-onset cataract formation. PMID:10727845

  8. Polarographic study of the Cu(II)/Cu(I) system in the presence of 1-ascorbic acid and 0,1 M ClK

    International Nuclear Information System (INIS)

    While studying the catalytic effect of Cu?2 ions on the oxidation process of 1-ascorbic acid, it has been observed that, in a 0,1 M solution of K1 at a pH 6 to 7, the above acid gives rise in the presence of Cu?2 ions to a polarographic wave of half-wave potential of -0,41 V (vs. S.C.E.). (Author) 14 refs

  9. Different modes of inhibition for organic acids on polyphenoloxidase.

    Science.gov (United States)

    Zhou, Lei; Liu, Wei; Xiong, Zhiqiang; Zou, Liqiang; Chen, Jun; Liu, Junping; Zhong, Junzhen

    2016-05-15

    It is still unclear whether the inhibitory effect of organic acid on polyphenoloxidase (PPO) is due to the reversible inhibition or decrease of pH. In this study, cinnamic acid, citric acid and malic acid inhibited PPO in different modes. Results showed that the inhibition by cinnamic acid resulted from reversible inhibition, while the decrease of pH was the main cause for citric acid and malic acid. The kinetic results showed that cinnamic acid reversibly inhibited PPO in a mixed-type manner. Fluorescence emission spectra indicated that cinnamic acid might interact with PPO and quench its intrinsic fluorescence, while the decrease of the fluorescence intensity induced by citric acid or malic acid was due to the acid-pH. Cinnamic acid bound to PPO and induced the rearrangement of secondary structure. Molecular docking result revealed cinnamic acid inserted into the hydrophobic cavity of PPO by forming ?-? stacking. PMID:26775993

  10. Scientific Opinion on the safety and efficacy of vitamin C (ascorbic acid, sodium ascorbate, calcium ascorbate, ascorbyl palmitate, sodium calcium ascorbyl phosphate and sodium ascorbyl phosphate) as a feed additive for all animal species based on a dossier submitted by DSM Nutritional Products Ltd

    OpenAIRE

    EFSA Panel on Additives and Products or Substances used in Animal Feed

    2013-01-01

    Vitamin C is essential for primates, guinea pigs and fish. Vitamin C, in the form of ascorbic acid and its calcium and sodium salts, ascorbyl palmitate, sodium calcium ascorbyl phosphate and sodium ascorbyl phosphate, is safe for all animal species. Setting a maximum content in feed and water for drinking is not considered necessary. Data on the vitamin C consumption of consumers are based on the levels of vitamin C in foodstuffs, including food of animal origin, produced in accordance with c...

  11. Exogenous salicylic acid improves photosynthesis and growth through increase in ascorbate-glutathione metabolism and S assimilation in mustard under salt stress

    Science.gov (United States)

    Nazar, Rahat; Umar, Shahid; Khan, Nafees A.

    2015-01-01

    Ascorbate (AsA)–glutathione (GSH) cycle metabolism has been regarded as the most important defense mechanism for the resistance of plants under stress. In this study the influence of salicylic acid (SA) was studied on ascorbate-glutathione pathway, S-assimilation, photosynthesis and growth of mustard (Brassica juncea L.) plants subjected to 100 mM NaCl. Treatment of SA (0.5 mM) alleviated the negative effects of salt stress and improved photosynthesis and growth through increase in enzymes of ascorbate-glutathione pathway which suggest that SA may participate in the redox balance under salt stress. The increase in leaf sulfur content through higher activity of ATP sulfurylase (ATPS) and serine acetyl transferase (SAT) by SA application was associated with the increased accumulation of glutathione (GSH) and lower levels of oxidative stress. These effects of SA were substantiated by the findings that application of SA-analog, 2,6, dichloro-isonicotinic acid (INA) and 1 mM GSH treatment produced similar results on rubisco, photosynthesis and growth of plants establishing that SA application alleviates the salt-induced decrease in photosynthesis mainly through inducing the enzyme activity of ascorbate-glutathione pathway and increased GSH production. Thus, SA/GSH could be a promising tool for alleviation of salt stress in mustard plants. PMID:25730495

  12. Industrialized cashew juices: variation of ascorbic acid and other physicochemical parameters / Sucos de caju industrializados: variação no teor de ácido ascórbico e em outros parâmetros físico-químicos

    Scientific Electronic Library Online (English)

    Christiane de Queiroz, Pereira; Flávia Conde, Lavinas; Maria Lúcia Mendes, Lopes; Vera Lúcia, Valente-Mesquita.

    2008-12-01

    Full Text Available Sucos de caju industrializados são amplamente aceitos no mercado brasileiro. O caju contém alto teor de ácido ascórbico, importante nutriente para o ser humano. O teor deste nutriente pode ser afetado pelo processamento e pelas condições de estocagem dos alimentos. Foram analisadas amostras de sucos [...] industrializados de caju, prontos para o consumo e concentrados. O teor de ácido ascórbico, a acidez total titulável, o teor de sólidos solúveis totais e o pH dos sucos foram determinados durante estocagem a 4 °C, após abertura das embalagens. Houve grande variabilidade no teor de ácido ascórbico entre as amostras, 37,3 a 46,3 mg.100 mL-1 nos sucos prontos para o consumo e 75,7 a 152 mg.100 mL-1 nos sucos concentrados. A estocagem dos sucos por 48 horas a 4 °C resultou em redução do teor de ácido ascórbico em até 8,8% para os concentrados e em até 6,4% para os prontos para o consumo. Os demais parâmetros analisados permaneceram estávei