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Sample records for astaxanthin chiral isomers

  1. Condensations of single DNA molecules induced by heptaplatin and its chiral isomer

    Science.gov (United States)

    Zhang, Hong-Yan; Liu, Yu-Ru; Li, Wei; Li, Hui; Dou, Shuo-Xing; Xie, Ping; Wang, Wei-Chi; Wang, Peng-Ye

    2014-08-01

    Heptaplatin is a third-generation platinum antitumor drug. It has a chiral isomer. We studied the interactions between the two isomers and DNA by using magnetic tweezers and atomic force microscopy (AFM) to investigate the effect of chiralities of the isomers on the interactions. We found that the extension curves and average condensation rates of DNA molecules incubated with heptaplatin were nearly the same as those incubated with its chiral isomer. In addition, the structures of DNA molecules incubated with heptaplatin were also similar to those incubated with its chiral isomer. These results indicate the difference in chirality of the two isomers does not induce different interactions of the isomers with DNA. Our study may facilitate the understanding of interactions of platinum complexes with DNA and the design of new antitumor platinum complexes.

  2. Quantitative trace analysis of eight chloramphenicol isomers in urine by chiral liquid chromatography coupled to tandem mass spectrometry.

    Science.gov (United States)

    Berendsen, Bjorn J A; Essers, Martien L; Stolker, Linda A A M; Nielen, Michel W F

    2011-10-14

    Chloramphenicol is a broad-spectrum antibiotic with, apart from its human medicinal use, veterinary abuse in all major food-producing animals. Chloramphenicol occurs in four stereoisomers (all para-nitro substituted) and furthermore four meta-nitro analogs of chloramphenicol exist. In this paper these are referred to as eight chloramphenicol isomers. According to EU regulations an analytical method should be able to discriminate the analyte from interfering substances that might be present in the sample, including isomers. For the first time a quantitative method for the analysis of trace levels of eight chloramphenicol isomers in urine by chiral liquid chromatography in combination with tandem mass spectrometric detection is reported. The separation of the isomers on the analytical column, the clean-up of urine and the selectivity of the monitored product ions turned out to be critical parameters. To obtain reproducible retention isocratic elution on a chiral AGP column was applied. For urine samples matrix compounds present in the final extract caused decreased retention of the isomers on the chiral stationary phase and a lack of chromatographic resolution. Therefore an extended clean-up procedure that combines solid phase extraction and liquid-liquid extraction had to be developed. The final method was fully validated and showed satisfactory performance for all isomers with decision limits (CCα) ranging from 0.005 to 0.03 μg L(-1) and within-laboratory reproducibility of all isomers below 20% at the minimum required performance limit level of 0.3 μg L(-1).

  3. Separation of positional CPP isomers by chiral HPLC-DAD of seized tablets.

    Science.gov (United States)

    Schürenkamp, Jennifer; Beike, Justus; Pfeiffer, Heidi; Köhler, Helga

    2011-01-01

    Meta-chlorophenylpiperazine, one of the synthetic piperazine-derived designer drugs, is to date controlled as an illicit substance in five European member states. Depending on the position of the chlorine atom, different positional isomers of CPP (ortho-, meta- and para-) are possible. Therefore, there is a need to develop an analytical method for the separation and identification of the three 1-chlorophenylpiperazines in tablets containing CPP. In this work, the position isomers o-, m- and p-CPP were separated by liquid chromatography (HPLC) on a reversed-phase chiral column. Different mobile phase compositions and pH ranges were systematically studied to find optimum chromatographic conditions. Best results were achieved with isocratic mobile phase of triethyl amine buffer and methanol (V/V = 70/30) at pH 9 with a flow rate of 0.8 ml/min. The method was validated in terms of selectivity, linearity, limit of detection and quantification and precision. At last, the developed method was successfully applied on seized ecstasy tablets.

  4. Unambiguous detection of astaxanthin and astaxanthin fatty acid esters in krill (Euphausia superba Dana).

    Science.gov (United States)

    Grynbaum, Marc David; Hentschel, Petra; Putzbach, Karsten; Rehbein, Jens; Krucker, Manfred; Nicholson, Graeme; Albert, Klaus

    2005-09-01

    HPLC atmospheric pressure chemical ionization (APCI)/MS, GC MS, HPLC diode array detection (DAD), and NMR were used for the identification of astaxanthin and astaxanthin fatty acid esters in krill (Euphausia superba Dana). Matrix solid phase dispersion was applied for the extraction of the carotenoids. This gentle and expeditious extraction technique for solid and viscous samples leads to distinct higher enrichment rates than the conventional liquid-liquid extraction. The chromatographic separation was achieved employing a C30 RP column that allows the separation of shape-constrained geometrical isomers. A methanol/tert-butylmethyl ether/water gradient was applied. (all-E) Astaxanthin and the geometrical isomers were identified by HPLC APCI/MS, by coelution with isomerized authentical standard, by UV spectroscopy (DAD), and three isomers were unambiguously assigned by microcoil NMR spectroscopy. In this method, microcoils are transversally aligned to the magnetic field and have an increased sensitivity compared to the conventional double-saddle Helmholtz coils, thus enabling the measurement on small samples. The carotenol fatty acid esters were saponified enzymatically with Lipase type VII from Candida rugosa. The fatty acids were detected by GC MS after transesterification, but also without previous derivatization by HPLC APCI/MS. C14:0, C16:0, C16:1, C18:1, C20:0, C20:5, and C22:6 were found in astaxanthin monoesters and in astaxanthin diesters. (all-E) Astaxanthin was identified as the main isomer in six fatty acid ester fractions by NMR. Quantitation was carried out by the method of internal standard. (13-cis) Astaxanthin (70 microg/g), 542 microg/g (all-E) astaxanthin, 36 microg/g unidentified astaxanthin isomer, 62 microg/g (9-cis) astaxanthin, and 7842 microg/g astaxanthin fatty acid esters were found.

  5. Effect of thermal processing on astaxanthin and astaxanthin esters in pacific white shrimp Litopenaeus vannamei.

    Science.gov (United States)

    Yang, Shu; Zhou, Qingxin; Yang, Lu; Xue, Yong; Xu, Jie; Xue, Changhu

    2015-01-01

    The red color of processed shrimp, one of the most attractive attributes and an important criterion for consumers, is often limited by thermal processing (microwaving, boiling and frying), due to astaxanthin degradation. The effect of thermal processing on astaxanthin in Pacific white shrimp (Litopenaeus vannamei) were investigated. A High-performance liquid chromatographic - atmospheric pressure chemical ionization mass spectrometry (LC-(APCI)-MS/MS) method was used to identify and quantify all-trans- and cis-isomers of astaxanthin, and molecular species of astaxanthin esters in fresh and thermal processed shrimps. Total astaxanthin loss ranged from 7.99% to 52.01% in first 3 min under three thermal processing. All-trans-astaxanthin was most affected, with a reduction from 32.81 to 8.72 μg kg(-1), while 13-cis-astxanthin had a rise (from 2.38 to 4.58 μg kg(-1)). Esterified astaxanthin was shown to hydrolyze and degrade, furthermore astaxanthin diesters had a better thermostability compare to astaxanthin monoesters. Astaxanthin monoesters with eicosapntemacnioc acid (EPA, C20:5) and docosahexaenoic acid (DHA, C22:6), had a lower thermal stability than those with saturated fatty acids, however, it was the opposite of astaxanthin diesters. The findings suggested that the method of thermal processing should be carefully used in the manufacturing and domestic cooking of shrimps. The results also could be useful in calculating the dietary intake of astaxanthin and in assessing astaxanthin profiles and contents of shrimp containing products.

  6. Determination of Other Related Carotenoids Substances in Astaxanthin Crystals Extracted from Adonis amurensis.

    Science.gov (United States)

    Zhang, Li-hua; Peng, Yong-jian; Xu, Xin-de; Wang, Sheng-nan; Yu, Lei-ming; Hong, Yi-min; Ma, Jin-ping

    2015-01-01

    Astaxanthin is a kind of important carotenoids with powerful antioxidation capacity and other health functions. Extracting from Adonis amurensis is a promising way to obtain natural astaxanthin. However, how to ensure the high purity and to investigate related substances in astaxanthin crystals are necessary issues. In this study, to identify possible impurities, astaxanthin crystal was first extracted from Adonis amurensis, then purified by saponification and separation. The concentration of total carotenoids in purified astaxanthin crystals was as high as 97% by weight when analyzed by UV-visible absorption spectra. After identified with TLC, HPLC and MS, besides free astaxanthin as main ingredient in the crystals, there existed four other unknown related substances, which were further investigated by HPLC/ESI/MS with the positive ion mode combining with other auxiliary reference data obtained in stress tests, at last it was confirmed that four related carotenoids substances were three structural isomers of semi-astacene and adonirubin.

  7. Chromatographic, NMR and vibrational spectroscopic investigations of astaxanthin esters: application to "Astaxanthin-rich shrimp oil" obtained from processing of Nordic shrimps.

    Science.gov (United States)

    Subramanian, B; Thibault, M-H; Djaoued, Y; Pelletier, C; Touaibia, M; Tchoukanova, N

    2015-11-01

    Astaxanthin (ASTX) is a keto carotenoid, which possesses a non-polar linear central conjugated chain and polar β-ionone rings with ketone and hydroxyl groups at the extreme ends. It is well known as a super anti-oxidant, and recent clinical studies have established its nutritional benefits. Although it occurs in several forms, including free molecule, crystalline, aggregates and various geometrical isomers, in nature it exists primarily in the form of esters. Marine animals accumulate ASTX from primary sources such as algae. Nordic shrimps (P. borealis), which are harvested widely in the Atlantic Ocean, form a major source of astaxanthin esters. "Astaxanthin-rich shrimp oil" was developed as a novel product in a shrimp processing plant in Eastern Canada. A compositional analysis of the shrimp oil was performed, with a view to possibly use it as a nutraceutical product for humans and animals. Astaxanthin-rich shrimp oil contains 50% MUFAs and 22% PUFAs, of which 20% are omega-3. In addition, the shrimp oil contains interesting amounts of EPA and DHA, with 10%/w and 8%/w, respectively. Astaxanthin concentrations varied between 400 and 1000 ppm, depending on the harvesting season of the shrimp. Astaxanthin and its esters were isolated from the oil and analysed by NMR, FTIR and Micro-Raman spectroscopy. Astaxanthin mono- and diesters were synthesized and used as standards for the analysis of astaxanthin-rich shrimp oil. NMR and vibrational spectroscopy techniques were successfully used for the rapid characterization of monoesters and diesters of astaxanthin. Raman spectroscopy provided important intermolecular interactions present in the esterified forms of astaxanthin molecules. Also discussed in this paper is the use of NMR, FTIR and Micro-Raman spectroscopy for the detection of astaxanthin esters in shrimp oil.

  8. ASTAXANTHIN: A POTENTIAL CAROTENOID

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    Jyotika Dhankhar et al.

    2012-05-01

    Full Text Available Astaxanthin, a member of the carotenoid family, is a dark-red pigment which is the main carotenoid found in the marine world of algae and aquatic animals. Astaxanthin, is present in many types of seafood, including salmon, trout, red sea bream, shrimp and lobster, as well as in birds such as flamingo and quail. Synthetic Astaxanthin dominates the world market but recent interest in natural sources of the pigment has increased substantially. Common sources of natural Astaxanthin, are the green algae haematococcus pluvialis, the red yeast, Phaffia rhodozyma, as well as crustacean byproducts. Astaxanthin possesses unusual antioxidant property which has caused a surge in the nutraceutical market of the encapsulated products. Numerous studies have shown that astaxanthin has potential health-promoting effects in the prevention and treatment of various diseases, such as cancers, chronic inflammatory diseases, metabolic syndrome, diabetes, diabetic nephropathy, cardiovascular diseases, gastrointestinal diseases, liver diseases, neurodegenerative diseases, eye diseases, skin diseases, exercise-induced fatigue, male infertility, and renal failure. In this article, the currently available scientific literature regarding the most significant activities of astaxanthin is reviewed.

  9. Chiral recognition of pinacidil and its 3-pyridyl isomer by canine cardiac and smooth muscle: Antagonism by sulfonylureas

    Energy Technology Data Exchange (ETDEWEB)

    Steinberg, M.I.; Wiest, S.A.; Zimmerman, K.M.; Ertel, P.J.; Bemis, K.G.; Robertson, D.W. (Eli Lilly and Company, Indianapolis, IN (USA))

    1991-01-01

    Pinacidil, a potassium channel opener (PCO), relaxes vascular smooth muscle by increasing potassium ion membrane conductance, thereby causing membrane hyperpolarization. PCOs also act on cardiac muscle to decrease action potential duration (APD) selectively. To examine the enantiomeric selectivity of pinacidil, the stereoisomers of pinacidil (a 4-pyridylcyanoguanidine) and its 3-pyridyl isomer (LY222675) were synthesized and studied in canine Purkinje fibers and cephalic veins. The (-)-enantiomers of both pinacidil and LY222675 were more potent in relaxing phenylephrine-contracted cephalic veins and decreasing APD than were their corresponding (+)-enantiomers. The EC50 values for (-)-pinacidil and (-)-LY222675 in relaxing cephalic veins were 0.44 and 0.09 microM, respectively. In decreasing APD, the EC50 values were 3.2 microM for (-)-pinacidil and 0.43 microM for (-)-LY222675. The eudismic ratio was greater for the 3-pyridyl isomer than for pinacidil in both cardiac (71 vs. 22) and vascular (53 vs. 17) tissues. (-)-LY222675 and (-)-pinacidil (0.1-30 microM) also increased 86Rb efflux from cephalic veins to a greater extent than did their respective optical antipodes. The antidiabetic sulfonylurea, glyburide (1-30 microM), shifted the vascular concentration-response curve of (-)-pinacidil to the right by a similar extent at each inhibitor concentration. Glipizide also antagonized the response to (-)-pinacidil, but was about 1/10 as potent with a maximal shift occurring at 10 and 30 microM. Glyburide antagonized the vascular relaxant effects of 0.3 microM (-)-LY222675 (EC50, 2.3 microM) and reversed the decrease in APD caused by 3 microM (-)-LY222675 (EC50, 1.9 microM). Nitroprusside did not alter 86Rb efflux, and vascular relaxation induced by sodium nitroprusside was unaffected by sulfonylureas.

  10. Protection of Astaxanthin in Astaxanthin Nanodispersions Using Additional Antioxidants

    OpenAIRE

    Chin Ping Tan; Imededdine Arbi Nehdi; Navideh Anarjan

    2013-01-01

    The protective effects of α-tocopherol and ascorbic acid on astaxanthin in astaxanthin nanodispersions produced via a solvent-diffusion technique and stabilized by a three-component stabilizer system, were studied either individually or in combination by using response surface methodology. Generally, both α-tocopherol and ascorbic acid could retard the astaxanthin degradation in astaxanthin nanodispersions. The results showed that the using α-tocopherol and ascorbic acid can be more efficient...

  11. Protection of astaxanthin in astaxanthin nanodispersions using additional antioxidants.

    Science.gov (United States)

    Anarjan, Navideh; Nehdi, Imededdine Arbi; Tan, Chin Ping

    2013-07-02

    The protective effects of α-tocopherol and ascorbic acid on astaxanthin in astaxanthin nanodispersions produced via a solvent-diffusion technique and stabilized by a three-component stabilizer system, were studied either individually or in combination by using response surface methodology. Generally, both α-tocopherol and ascorbic acid could retard the astaxanthin degradation in astaxanthin nanodispersions. The results showed that the using α-tocopherol and ascorbic acid can be more efficient in increasing the chemical stability of nanodispersions in comparison to using them individually. Using a response surface methodology (RSM) response optimizer, it was seen that addition of ascorbic acid (ascorbic acid/astaxanthin w/w) and α-tocopherol (α-tocopherol/astaxanthin w/w) in proportions of 0.4 and 0.6, respectively, would give the maximum chemical stability to the studied astaxanthin nanodispersions.

  12. Protection of Astaxanthin in Astaxanthin Nanodispersions Using Additional Antioxidants

    Directory of Open Access Journals (Sweden)

    Chin Ping Tan

    2013-07-01

    Full Text Available The protective effects of α-tocopherol and ascorbic acid on astaxanthin in astaxanthin nanodispersions produced via a solvent-diffusion technique and stabilized by a three-component stabilizer system, were studied either individually or in combination by using response surface methodology. Generally, both α-tocopherol and ascorbic acid could retard the astaxanthin degradation in astaxanthin nanodispersions. The results showed that the using α-tocopherol and ascorbic acid can be more efficient in increasing the chemical stability of nanodispersions in comparison to using them individually. Using a response surface methodology (RSM response optimizer, it was seen that addition of ascorbic acid (ascorbic acid/astaxanthin w/w and α-tocopherol (α-tocopherol/astaxanthin w/w in proportions of 0.4 and 0.6, respectively, would give the maximum chemical stability to the studied astaxanthin nanodispersions.

  13. Antihypertensive effects of astaxanthin

    OpenAIRE

    Yanai, Hidekatsu

    2008-01-01

    Hidekatsu Yanai1,2, Kumie Ito1,2, Hiroshi Yoshida2,3, Norio Tada1,21Department of Internal Medicine; 2Institute of Clinical Medicine and Research; 3Department of Laboratory Medicine, The Jikei University School of Medicine, Chiba, JapanAbstract: Astaxanthin is a biological antioxidant naturally found in a wide variety of aquatic living organisms, and has shown various pharmacological activities, such as anti-inflammatory and antidiabetic activities. A recent study reported that the administra...

  14. Absorption Spectra of Astaxanthin Aggregates

    CERN Document Server

    Olsina, Jan; Minofar, Babak; Polivka, Tomas; Mancal, Tomas

    2012-01-01

    Carotenoids in hydrated polar solvents form aggregates characterized by dramatic changes in their absorption spectra with respect to monomers. Here we analyze absorption spectra of aggregates of the carotenoid astaxanthin in hydrated dimethylsulfoxide. Depending on water content, two types of aggregates were produced: H-aggregates with absorption maximum around 390 nm, and J-aggregates with red-shifted absorption band peaking at wavelengths >550 nm. The large shifts with respect to absorption maximum of monomeric astaxanthin (470-495 nm depending on solvent) are caused by excitonic interaction between aggregated molecules. We applied molecular dynamics simulations to elucidate structure of astaxanthin dimer in water, and the resulting structure was used as a basis for calculations of absorption spectra. Absorption spectra of astaxanthin aggregates in hydrated dimethylsulfoxide were calculated using molecular exciton model with the resonance interaction energy between astaxanthin monomers constrained by semi-e...

  15. Construction of the astaxanthin biosynthetic pathway in a methanotrophic bacterium Methylomonas sp. strain 16a.

    Science.gov (United States)

    Ye, Rick W; Yao, Henry; Stead, Kristen; Wang, Tao; Tao, Luan; Cheng, Qiong; Sharpe, Pamela L; Suh, Wonchul; Nagel, Eva; Arcilla, Dennis; Dragotta, Dominic; Miller, Edward S

    2007-04-01

    Methylomonas sp. strain 16a is an obligate methanotrophic bacterium that uses methane or methanol as the sole carbon source. An effort was made to engineer this organism for astaxanthin production. Upon expressing the canthaxanthin gene cluster under the control of the native hps promoter in the chromosome, canthaxanthin was produced as the main carotenoid. Further conversion to astaxanthin was carried out by expressing different combinations of crtW and crtZ genes encoding the beta-carotenoid ketolase and hydroxylase. The carotenoid intermediate profile was influenced by the copy number of these two genes under the control of the hps promoter. Expression of two copies of crtZ and one copy of crtW led to the accumulation of a large amount of the mono-ketolated product adonixanthin. On the other hand, expression of two copies of crtW and one copy of crtZ resulted in the presence of non-hydroxylated carotenoid canthaxanthin and the mono-hydroxylated adonirubin. Production of astaxanthin as the predominant carotenoid was obtained in a strain containing two complete sets of carotenoid biosynthetic genes. This strain had an astaxanthin titer ranging from 1 to 2.4 mg g(-1) of dry cell biomass depending on the growth conditions. More than 90% of the total carotenoid was astaxanthin, of which the majority was in the form of E-isomer. This result indicates that it is possible to produce astaxanthin with desirable properties in methanotrophs through genetic engineering.

  16. Determination of astaxanthin stereoisomers and colour attributes in flesh of rainbow trout (Oncorhynchus mykiss) as a tool to distinguish the dietary pigmentation source.

    Science.gov (United States)

    Moretti, V M; Mentasti, T; Bellagamba, F; Luzzana, U; Caprino, F; Turchini, G M; Giani, I; Valfrè, F

    2006-11-01

    The presence of carotenoids in animal tissue reflects their sources along the food chain. Astaxanthin, the main carotenoid used for salmonid pigmentation, is usually included in the feed as a synthetic product. However, other dietary sources of astaxanthin such as shrimp or krill wastes, algae meal or yeasts are also available on the market. Astaxanthin possesses two identical asymmetric atoms at C-3 and C-3' making possible three optical isomers with all-trans configuration of the chain: 3S,3'S, 3R,3'S, and 3R,3'R. The distribution of the isomers in natural astaxanthin differs from that of the synthetic product. This latter is a racemic mixture, with a typical ratio of 1:2:1 (3S,3'S:3R,3'S:3R,3'R), while astaxanthin from natural sources has a variable distribution of the isomers deriving from the different biological organism that synthesized it. The high-performance liquid chromatographic (HPLC) analysis of all-trans isomers of astaxanthin was performed in different pigment sources, such as red yeast Phaffia rhodozyma, alga meal Haematococcus pluvialis, krill meal and oil, and shrimp meal. With the aim to investigate astaxanthin isomer ratios in flesh of fish fed different carotenoid sources, three groups of rainbow trout were fed for 60 days diets containing astaxanthin from synthetic source, H. pluvialis algae meal and P. rhodozyma red yeast. Moreover, the distribution of optical isomers of astaxanthin in trout purchased on the Italian market was investigated. A characteristic distribution of astaxanthin stereoisomers was detected for each pigment sources and such distribution was reproduced in the flesh of trout fed with that source. Colour values measured in different sites of fillet of rainbow trout fed with different pigment sources showed no significant differences. Similarly, different sources of pigment (natural or synthetic) produced colour values of fresh fillet with no relevant or significant differences. The coefficient of distance computed amongst

  17. Fatty acids attached to all-trans-astaxanthin alter its cis-trans equilibrium, and consequently its stability, upon light-accelerated autoxidation.

    Science.gov (United States)

    de Bruijn, Wouter J C; Weesepoel, Yannick; Vincken, Jean-Paul; Gruppen, Harry

    2016-03-01

    Fatty acid esterification, common in naturally occurring astaxanthin, has been suggested to influence both colour stability and degradation of all-trans-astaxanthin. Therefore, astaxanthin stability was studied as influenced by monoesterification and diesterification with palmitate. Increased esterification decelerated degradation of all-trans-astaxanthin (RP-UHPLC-PDA), whereas, it had no influence on colour loss over time (spectrophotometry). This difference might be explained by the observation that palmitate esterification influenced the cis-trans equilibrium. Free astaxanthin produced larger amounts of 9-cis isomer whereas monopalmitate esterification resulted in increased 13-cis isomerization. The molar ratios of 9-cis:13-cis after 60min were 1:1.7 (free), 1:4.8 (monopalmitate) and 1:2.6 (dipalmitate). The formation of 9-cis astaxanthin, with its higher molar extinction coefficient than that of all-trans-astaxanthin, might compensate for colour loss induced by conjugated double bond cleavage. As such, it was concluded that spectrophotometry is not an accurate measure of the degradation of the all-trans-astaxanthin molecule.

  18. 21 CFR 73.35 - Astaxanthin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Astaxanthin. 73.35 Section 73.35 Food and Drugs... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.35 Astaxanthin. (a) Identity. (1) The color additive astaxanthin is 3, 3′-dihydroxy-β, β-carotene-4, 4′-dione. (2) Astaxanthin may be added to the fish feed...

  19. Astaxanthin uptake in domestic dogs and cats

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    Massimino Stefan

    2010-06-01

    Full Text Available Abstract Background Research on the uptake and transport of astaxanthin is lacking in most species. We studied the uptake of astaxanthin by plasma, lipoproteins and leukocytes in domestic dogs and cats. Methods Mature female Beagle dogs (18 to 19 mo old; 11 to 14 kg BW were dosed orally with 0, 0.1, 0.5, 2.5, 10 or 40 mg astaxanthin and blood taken at 0, 3, 6, 9, 12, 18 and 24 h post-administration (n = 8/treatment. Similarly, mature domestic short hair cats (12 mo old; 3 to 3.5 kg body weight were fed a single dose of 0, 0.02, 0.08, 0.4, 2, 5, or 10 mg astaxanthin and blood taken (n = 8/treatment at the same interval. Results Both dogs and cats showed similar biokinetic profiles. Maximal astaxanthin concentration in plasma was approximately 0.14 μmol/L in both species, and was observed at 6 h post-dosing. The plasma astaxanthin elimination half-life was 9 to 18 h. Astaxanthin was still detectable by 24 h in both species. In a subsequent study, dogs and cats were fed similar doses of astaxanthin daily for 15 to 16 d and astaxanthin uptake by plasma, lipoproteins, and leukocytes studied. In both species, plasma astaxanthin concentrations generally continued to increase through d 15 or 16 of supplementation. The astaxanthin was mainly associated with high density lipoprotein (HDL. In blood leukocytes, approximately half of the total astaxanthin was found in the mitochondria, with significant amounts also associated with the microsomes and nuclei. Conclusion Dogs and cats absorb astaxanthin from the diet. In the blood, the astaxanthin is mainly associated with HDL, and is taken up by blood leukocytes, where it is distributed to all subcellular organelles. Certain aspects of the biokinetic uptake of astaxanthin in dogs and cats are similar to that in humans.

  20. Downregulation of steroid hormone receptor expression and activation of cell signal transduction pathways induced by a chiral nonylphenol isomer in mouse sertoli TM4 cells.

    Science.gov (United States)

    Liu, Xiaozhen; Nie, Shaoping; Yu, Qiang; Wang, Xiaoyin; Huang, Danfei; Xie, Mingyong

    2017-02-01

    Nonylphenols (NPs) are considered as important environmental toxicants and potential endocrine disrupting compounds which can disrupt male reproductive system. 4-[1-Ethyl-1-methylhexy] phenol (4-NP65 ) is one of the main isomers of technical nonylphenol mixtures. In the present study, effect of NPs was evaluated from an isomer-specific viewpoint using 4-NP65 . Decreased mRNA expression levels of estrogen receptor (ER)-α, ER-β, androgen receptor (AR) and progesterone receptor (PR) were observed in the cells exposed to 4-NP65 for 24 h. Furthermore, 4-NP65 treatment evoked significant decrease in protein expression levels of ER-α and ER-β. Levels of mullerian inhibiting substance and transferrin were found to change significantly in 4-NP65 challenged cells. Additionally, JNK1/2-MAPK pathway was activated due to 4-NP65 exposure, but not ERK1/2 and p38-MAPK pathways. Meanwhile, 4-NP65 increased the p-Akt level and showed no effects on the Akt level which indicated that Akt pathway was activated by 4-NP65 . In conclusion, these findings have shown that 4-NP65 exposure affected expression of cell receptors and cell signaling pathways in Sertoli TM4 cells. We proposed that molecular mechanism of reproductive damage in Sertoli cells induced by NPs may be mediated by cell receptors and/or cell signal transduction pathways, and that the effects were dependent on the side chain of NP isomers. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 469-476, 2017.

  1. Potential Anti-Atherosclerotic Properties of Astaxanthin.

    Science.gov (United States)

    Kishimoto, Yoshimi; Yoshida, Hiroshi; Kondo, Kazuo

    2016-02-05

    Astaxanthin is a naturally occurring red carotenoid pigment classified as a xanthophyll, found in microalgae and seafood such as salmon, trout, and shrimp. This review focuses on astaxanthin as a bioactive compound and outlines the evidence associated with its potential role in the prevention of atherosclerosis. Astaxanthin has a unique molecular structure that is responsible for its powerful antioxidant activities by quenching singlet oxygen and scavenging free radicals. Astaxanthin has been reported to inhibit low-density lipoprotein (LDL) oxidation and to increase high-density lipoprotein (HDL)-cholesterol and adiponectin levels in clinical studies. Accumulating evidence suggests that astaxanthin could exert preventive actions against atherosclerotic cardiovascular disease (CVD) via its potential to improve oxidative stress, inflammation, lipid metabolism, and glucose metabolism. In addition to identifying mechanisms of astaxanthin bioactivity by basic research, much more epidemiological and clinical evidence linking reduced CVD risk with dietary astaxanthin intake is needed.

  2. A novel radio-tolerant astaxanthin-producing bacterium reveals a new astaxanthin derivative: astaxanthin dirhamnoside.

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    Asker, Dalal; Awad, Tarek S; Beppu, Teruhiko; Ueda, Kenji

    2012-01-01

    Astaxanthin is a red ketocarotenoid that exhibits extraordinary health-promoting activities such as antioxidant, anti-inflammatory, antitumor, and immune booster. The recent discovery of the beneficial roles of astaxanthin against many degenerative diseases such as cancers, heart diseases, and exercise-induced fatigue has raised its market demand as a nutraceutical and medicinal ingredient in aquaculture, food, and pharmaceutical industries. To satisfy the growing demand for this high-value nutraceuticals ingredient and consumer interest in natural products, many research efforts are being made to discover novel microbial producers with effective biotechnological production of astaxanthin. Using a rapid screening method based on 16S rRNA gene, and effective HPLC-Diodearray-MS methods for carotenoids analysis, we succeeded to isolate a unique astaxanthin-producing bacterium (strain TDMA-17(T)) that belongs to the family Sphingomonadaceae (Asker et al., Appl Microbiol Biotechnol 77: 383-392, 2007). In this chapter, we provide a detailed description of effective HPLC-Diodearray-MS methods for rapid analysis and identification of the carotenoids produced by strain TDMA-17(T). We also describe the methods of isolation and identification for a novel bacterial carotenoid (astaxanthin derivative), a major carotenoid that is produced by strain TDMA-17(T). Finally, we describe the polyphasic taxonomic analysis of strain TDMA-17(T) and the description of a novel species belonging to genus Sphingomonas.

  3. Astaxanthin as a Medical Food

    Directory of Open Access Journals (Sweden)

    Eiji Yamashita

    2013-07-01

    Full Text Available ABSTRACTAstaxanthin is a red pigment that belongs to the carotenoid family like β-carotene. And it’s found in seafood such as crustaceans: shrimp and crabs and fish: salmon and sea bream. Recently, astaxanthin has been reported to have antioxidant activity up to 100 times more potent than that of vitamin E against lipid peroxidation and about 40 times more potent than that of β-carotene on singlet oxygen quenching. Astaxanthin does not show any pro-oxidant activity and its main sight of action is on/in the cell membrane. Various important benefits to date have suggested for human health such as immunomodulation, anti-stress, anti-inflammation, LDL cholesterol oxidation suppression, enhanced skin health, improved semen quality, attenuating eye fatigue, sport performance and endurance, limiting exercised induced muscle damage, suppressing the development of life-style related diseases such as obesity, atherosclerosis, diabetes, hyperlipidemia and hypertension. Nowadays, the research and demand for natural astaxanthin in human health application are explosively growing worldwide. Especially, the clinicians use the astaxanthin extracted from the microalgae, Haematotoccus pluvialis, as an add-on supplementation for the patients who are unsatisfied with the current medications or who can’t receive any medications because of their serious symptom. For example, the treatment enhances their daily activity levels or QOL in heart failure or benign prostatic hypertrophy/lower urinary tract symptom patients. Other studies and trials are under way on chronic diseases such as non-alcoholic steatohepatitis, diabetes and CVD. We may call astaxanthin “a medical food” in the near future.Keywords: astaxanthin, medical food, Haematococcus, add-on supplementation

  4. Astaxanthin diferulate as a bifunctional antioxidant

    DEFF Research Database (Denmark)

    Papa, T.B.R.; Pinho, V.D.; Nascimento, E.P. do;

    2015-01-01

    Abstract Astaxanthin when esterified with ferulic acid is better singlet oxygen quencher with k2 = (1.58 ± 0.1) 10(10) L mol(- 1)s(- 1) in ethanol at 25°C compared with astaxanthin with k2 = (1.12 ± 0.01) 10(9) L mol(- 1)s(- 1). The ferulate moiety in the astaxanthin diester is a better radical s....... The mutual enhancement of antioxidant activity for the newly synthetized astaxanthin diferulate becoming a bifunctional antioxidant is rationalized according to a two-dimensional classification plot for electron donation and electron acceptance capability....

  5. Hydrolysis kinetics of astaxanthin esters and stability of astaxanthin of Haematococcus pluvialis during saponification.

    Science.gov (United States)

    Yuan, J P; Chen, F

    1999-01-01

    The reaction kinetics for the hydrolysis of astaxanthin esters and the degradation of astaxanthin during saponification of the pigment extract from the microalga Haematococcus pluvialis were investigated. Different concentrations of sodium hydroxide in methanol were used for the saponification under nitrogen in darkness at ambient temperature (22 degrees C) followed by the analysis of astaxanthins and other carotenoids using an HPLC method. The concentration of methanolic NaOH solution was important for promoting the hydrolysis of astaxanthin esters and minimizing the degradation of astaxanthin during saponification. With a higher concentration of methanolic NaOH solution, the reaction rate of hydrolysis was high, but the degradation of astaxanthin occurred significantly. The rate constants of the hydrolysis reaction (first order) of astaxanthin esters and the degradation reaction (zero-order) of astaxanthin were directly proportional to the concentration of sodium hydroxide in the saponified solution. Although the concentration of sodium hydroxide in the saponified solution was 0.018 M, complete hydrolysis of astaxanthin esters was achieved in 6 h for different concentrations (10-100 mg/L) of pigment extracts. Results also indicated that a higher temperature should be avoided to minimize the degradation of astaxanthin. In addition, during saponification, no loss of lutein, beta-carotene, and canthaxanthin was found.

  6. Characterization and storage stability of astaxanthin esters, fatty acid profile and α-tocopherol of lipid extract from shrimp (L. vannamei) waste with potential applications as food ingredient.

    Science.gov (United States)

    Gómez-Estaca, J; Calvo, M M; Álvarez-Acero, I; Montero, P; Gómez-Guillén, M C

    2017-02-01

    In this work a lipid extract from shrimp waste was obtained and characterized. The most abundant fatty acids found were C16:0, C18:2n6c, C18:1n9c, C22:6n3, and C20:5n3. The extract contained all-trans-astaxanthin, two cis-astaxanthin isomers, 5 astaxanthin monoesters, and 10 astaxanthin diesters (7±1mg astaxanthin/g). C22:6n3 and C20:5n3 were the most frequent fatty acids in the esterified forms. Appreciable amounts of α-tocopherol and cholesterol were also found (126±11mg/g and 65±1mg/g, respectively). Little lipid oxidation was observed after 120days of storage at room temperature, revealed by a slight reduction of ω-3 fatty acids, but neither accumulation of TBARS nor formation of oxidized cholesterol forms was found. This is attributed to the antioxidant effect of astaxanthin and α-tocopherol, as their concentrations decreased as storage continued. The lipid extract obtained has interesting applications as food ingredient, owing to the coloring capacity and the presence of healthy components.

  7. Chirality in Bare and Passivated Gold Nanoclusters

    CERN Document Server

    Garzon, I L; Rodrigues-Hernandez, J I; Sigal, I; Beltran, M R; Michaelian, K

    2002-01-01

    Chiral structures have been found as the lowest-energy isomers of bare (Au$_{28}$ and Au$_{55}) and thiol-passivated (Au$_{28}(SCH$_{3})$_{16}$ and Au$_{38}$(SCH$_{3}$)$_{24}) gold nanoclusters. The degree of chirality existing in the chiral clusters was calculated using the Hausdorff chirality measure. We found that the index of chirality is higher in the passivated clusters and decreases with the cluster size. These results are consistent with the observed chiroptical activity recently reported for glutahione-passivated gold nanoclusters, and provide theoretical support for the existence of chirality in these novel compounds.

  8. [Effect of astaxanthin on preeclampsia rat model].

    Science.gov (United States)

    Xuan Rong-rong; Gao Xin; Wu, Wei; Chen, Hai-min

    2014-10-01

    The effect of astaxanthin on N(Ω)-nitro-L-arginine methyl ester (L-NAME) induced preeclampsia disease rats was investigated. Thirty pregnant Sprague-Dawley rats were randomly divided into three groups (n = 10): blank group, L-NAME group and astaxanthin group. From day 5 to 20, astaxanthin group rats were treated with astaxanthin (25 mg x kg(-1) x d(-1) x bw(-1)) from pregnancy (day 5). To establish the preeclamptic rat model, L-NAME group and astaxanthin group rats were injected with L-NAME (125 mg x kg(-1) x d(-1) x bw(-1)) from days 10-20 of pregnancy. The blood pressure and urine protein were recorded. Serum of each group was collected and malondialdehyde (MDA), superoxide dismutase (SOD) and nitric oxide synthase (NOS) activities were analyzed. Pathological changes were observed with HE stain. The expression of NF-κB (nuclear factor kappa B), ROCK II (Rho-associated protein kinase II), HO-1 (heme oxygenase-1) and Caspase 3 were analyzed with immunohistochemistry. L-NAME induced typical preeclampsia symptoms, such as the increased blood pressure, urinary protein, the content of MDA, etc. Astaxanthin significantly reduced the blood pressure (P astaxanthin, the thickness of basilal membrane was improved and the content of trophoblast cells and spiral arteries was reduced. Immunohistochemistry results revealed that the expressions of NF-κB, ROCK II and Caspase 3 in placenta tissue were effectively decreased, and HO-1 was increased. Results indicated that astaxanthin can improve the preeclampsia symptoms by effectively reducing the oxidative stress and inflammatory damages of preeclampsia. It revealed that astaxanthin may be benefit for prevention and treatment of preeclampsia disease.

  9. Simultaneous determination of 13 carotenoids by a simple C18 column-based ultra-high-pressure liquid chromatography method for carotenoid profiling in the astaxanthin-accumulating Haematococcus pluvialis.

    Science.gov (United States)

    Jin, Hui; Lao, Yong Min; Zhou, Jin; Zhang, Huai Jin; Cai, Zhong Hua

    2017-03-10

    A simple ultra-high-pressure liquid chromatography (UHPLC) method for rapidly and simultaneously identifying thirteen carotenoids in Haematococcus pluvialis was developed in this study. The method is capable of effectively separating two astaxanthin isomers, two ζ-carotene isomers, and three phytoene isomers on two simple C18 columns within 9 and 12min only by using methanol and acetonitrile, respectively. To our best knowledge, this is the rapidest method for these carotenoid isomers, currently. Using this method, carotenoid profiling in the astaxanthin-accumulating H. pluvialis under environmental stresses was successfully carried out. Results indicated that carotenoid biosynthesis was differentially perturbed by environmental stresses, indicating that this simple and rapid method is suitable to not only bacterial but also algal samples, with potential applications for a wide range of samples from plant to animal. Finally, possible reasons for the elution order of carotenoids were studied.

  10. Astaxanthin dynamics in Baltic Sea mesozooplankton communities

    Science.gov (United States)

    Snoeijs, Pauline; Häubner, Norbert

    2014-01-01

    The red pigment astaxanthin is a powerful antioxidant, which occurs in eggs and body tissues of crustaceans and fish. It is produced by crustaceans from algal carotenoids. In a two-year field study we assessed natural concentrations and dynamics of astaxanthin in mesozooplankton communities in the brackish Baltic Sea area. Astaxanthin levels varied between 0.37 and 36 ng L- 1. They increased with salinity along the Baltic Sea gradient and were linked to zooplankton biomass and phytoplankton community composition. Astaxanthin concentrations showed typical seasonal patterns and varied from 0.2 to 5.1 ng ind- 1, 0.2 to 3.4 ng (μg C)- 1 and 6 to 100 ng mm- 3. These concentrations were inversely related to water temperature and strongly linked to zooplankton community composition. Communities dominated by the calanoid copepods Temora longicornis, Pseudocalanus acuspes and Eurytemora spp. generally held the highest concentrations. With increasing cladocerans:copepods biomass ratios community astaxanthin concentrations decreased and with higher relative biomass of Acartia spp. the proportion of astaxanthin diesters decreased. Diesters prevailed in the cold season and they are thought to improve the antioxidant protection of storage lipids during winter. Climate change causes higher temperature and lower salinity in the Baltic Sea proper. This modifies zooplankton community composition, but not necessarily into a community with lower concentrations of astaxanthin since T. longicornis (high concentrations) has been reported to increase with higher temperature. However, decreased astaxanthin production in the ecosystem is expected if a basin-wide increase in the cladocerans:copepods biomass ratios would occur with further climate change.

  11. Astaxanthin in cardiovascular health and disease.

    Science.gov (United States)

    Fassett, Robert G; Coombes, Jeff S

    2012-02-20

    Oxidative stress and inflammation are established processes contributing to cardiovascular disease caused by atherosclerosis. However, antioxidant therapies tested in cardiovascular disease such as vitamin E, C and β-carotene have proved unsuccessful at reducing cardiovascular events and mortality. Although these outcomes may reflect limitations in trial design, new, more potent antioxidant therapies are being pursued. Astaxanthin, a carotenoid found in microalgae, fungi, complex plants, seafood, flamingos and quail is one such agent. It has antioxidant and anti-inflammatory effects. Limited, short duration and small sample size studies have assessed the effects of astaxanthin on oxidative stress and inflammation biomarkers and have investigated bioavailability and safety. So far no significant adverse events have been observed and biomarkers of oxidative stress and inflammation are attenuated with astaxanthin supplementation. Experimental investigations in a range of species using a cardiac ischaemia-reperfusion model demonstrated cardiac muscle preservation when astaxanthin is administered either orally or intravenously prior to the induction of ischaemia. Human clinical cardiovascular studies using astaxanthin therapy have not yet been reported. On the basis of the promising results of experimental cardiovascular studies and the physicochemical and antioxidant properties and safety profile of astaxanthin, clinical trials should be undertaken.

  12. Antioxidant effect of astaxanthin on phospholipid peroxidation in human erythrocytes.

    Science.gov (United States)

    Nakagawa, Kiyotaka; Kiko, Takehiro; Miyazawa, Taiki; Carpentero Burdeos, Gregor; Kimura, Fumiko; Satoh, Akira; Miyazawa, Teruo

    2011-06-01

    Phospholipid hydroperoxides (PLOOH) accumulate abnormally in the erythrocytes of dementia patients, and dietary xanthophylls (polar carotenoids such as astaxanthin) are hypothesised to prevent the accumulation. In the present study, we conducted a randomised, double-blind, placebo-controlled human trial to assess the efficacy of 12-week astaxanthin supplementation (6 or 12 mg/d) on both astaxanthin and PLOOH levels in the erythrocytes of thirty middle-aged and senior subjects. After 12 weeks of treatment, erythrocyte astaxanthin concentrations were higher in both the 6 and 12 mg astaxanthin groups than in the placebo group. In contrast, erythrocyte PLOOH concentrations were lower in the astaxanthin groups than in the placebo group. In the plasma, somewhat lower PLOOH levels were found after astaxanthin treatment. These results suggest that astaxanthin supplementation results in improved erythrocyte antioxidant status and decreased PLOOH levels, which may contribute to the prevention of dementia.

  13. 21 CFR 73.37 - Astaxanthin dimethyl-disuccinate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Astaxanthin dimethyl-disuccinate. 73.37 Section 73... LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.37 Astaxanthin dimethyl-disuccinate. (a) Identity. (1) The color additive astaxanthin dimethyldisuccinate is...

  14. Astaxanthin diferulate as a bifunctional antioxidant.

    Science.gov (United States)

    Papa, T B R; Pinho, V D; do Nascimento, E S P; Santos, W G; Burtoloso, A C B; Skibsted, L H; Cardoso, D R

    2015-01-01

    Astaxanthin when esterified with ferulic acid is better singlet oxygen quencher with k2 = (1.58 ± 0.1) 10(10) L mol(-1)s(-1) in ethanol at 25°C compared with astaxanthin with k2 = (1.12 ± 0.01) 10(9) L mol(-1)s(-1). The ferulate moiety in the astaxanthin diester is a better radical scavenger than free ferulic acid as seen from the rate constant of scavenging of 1-hydroxyethyl radicals in ethanol at 25°C with a second-order rate constant of (1.68 ± 0.1) 10(8) L mol(-1)s(-1) compared with (1.60 ± 0.03) 10(7) L mol(-1)s(-1) for the astaxanthin:ferulic acid mixture, 1:2 equivalents. The mutual enhancement of antioxidant activity for the newly synthetized astaxanthin diferulate becoming a bifunctional antioxidant is rationalized according to a two-dimensional classification plot for electron donation and electron acceptance capability.

  15. Astaxanthin reduces matrix metalloproteinase expression in human chondrocytes.

    Science.gov (United States)

    Chen, Wei-Ping; Xiong, Yan; Shi, Yong-Xiang; Hu, Peng-Fei; Bao, Jia-Peng; Wu, Li-Dong

    2014-03-01

    Astaxanthin is a red carotenoid pigment which exerts multiple biological activities. However, little is known about the effects of astaxanthin on matrix metalloproteinases (MMPs) in OA. The present study investigated the effects of astaxanthin on MMPs in human chondrocytes. Human chondrocytes were pretreated with astaxanthin at 1, 10 or 50μM, then, cells were stimulated with IL-1β (10ng/ml) for 24h. MMP-1, MMP-3 and MMP-13 were observed. We found that astaxanthin reduced the expression of MMP-1, MMP-3 and MMP-13 as well as the phosphorylation of two mitogen-activated protein kinases (MAPK) (p38 and ERK1/2) in IL-1β-stimulated chondrocytes. Astaxanthin also blocked the IκB-α degradation. These results suggest that astaxanthin may be beneficial in the treatment of OA.

  16. Biotechnological production of astaxanthin with Phaffia rhodozyma/Xanthophyllomyces dendrorhous.

    Science.gov (United States)

    Schmidt, Isabell; Schewe, Hendrik; Gassel, Sören; Jin, Chao; Buckingham, John; Hümbelin, Markus; Sandmann, Gerhard; Schrader, Jens

    2011-02-01

    The oxygenated β-carotene derivative astaxanthin exhibits outstanding colouring, antioxidative and health-promoting properties and is mainly found in the marine environment. To satisfy the growing demand for this ketocarotenoid in the feed, food and cosmetics industries, there are strong efforts to develop economically viable bioprocesses alternative to the current chemical synthesis. However, up to now, natural astaxanthin from Haematococcus pluvialis, Phaffia rhodozyma or Paracoccus carotinifaciens has not been cost competitive with chemically synthesized astaxanthin, thus only serving niche applications. This review illuminates recent advances made in elucidating astaxanthin biosynthesis in P. rhodozyma. It intensely focuses on strategies to increase astaxanthin titers in the heterobasidiomycetous yeast by genetic engineering of the astaxanthin pathway, random mutagenesis and optimization of fermentation processes. This review emphasizes the potential of P. rhodozyma for the biotechnological production of astaxanthin in comparison to other natural sources such as the microalga H. pluvialis, other fungi and transgenic plants and to chemical synthesis.

  17. Excited-state dynamics of astaxanthin aggregates

    Science.gov (United States)

    Fuciman, Marcel; Durchan, Milan; Šlouf, Václav; Keşan, Gürkan; Polívka, Tomáš

    2013-05-01

    Astaxanthin forms three types of aggregates in hydrated dimethyl sulfoxide (DMSO). In DMSO/water ratio of 1:1, a red-shifted J-aggregate with maximum at 570 nm is generated, while a ratio of 1:9 produces blue-shifted H-aggregates with peaks at 386 nm (H1) and 460 nm (H2). Monomeric astaxanthin in DMSO has an S1 lifetime of 5.3 ps, but a long-lived (33 ps) S∗ signal was also identified. Aggregation changes the S1 lifetimes to 17 ps (H1), 30 ps (H2), and 14 ps (J). Triplet state of astaxanthin, most likely generated via singlet homofission, was observed in H1 and H2 aggregates.

  18. Efektifitas Astaxanthin Oral disertai Gel Astaxanthin Dibandingkan dengan Astaxanthin Oral disertai Krim Triple Combination (Hidrokuinon 4%, Tretinoin 0,05%, Fluosinolon Asetonid 0,01%) dalam Pengobatan Melasma

    OpenAIRE

    Lubis, Faridah Israwaty

    2011-01-01

    Background : Melasma is a common acquired symmetrical hypermelanosis that occurs on sun-exposed facial areas. Melasma is frequently observed among women. Many modalities of treatment are available but none is satisfactory. Aim : To compare the efficacy and safety of oral astaxanthin combined with astaxanthin gel and oral astaxanthin combined with triple combination cream in the treatment of melasma. Subject and methods : A double blind, randomize, clinical trial design study was condu...

  19. High-harmonic spectroscopy of molecular isomers

    Energy Technology Data Exchange (ETDEWEB)

    Wong, M. C. H.; Brichta, J.-P.; Bhardwaj, V. R. [Department of Physics, University of Ottawa, 150 Louis-Pasteur, Ottawa, Ontario, K1N 6N5 (Canada); Spanner, M.; Patchkovskii, S. [National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario, K1A 0R6 (Canada)

    2011-11-15

    We demonstrate that high-order-harmonic generation (HHG) spectroscopy can be used to probe stereoisomers of randomly oriented 1,2-dichloroethylene (C{sub 2}H{sub 2}Cl{sub 2}) and 2-butene (C{sub 4}H{sub 8}). The high-harmonic spectra of these isomers are distinguishable over a range of laser intensities and wavelengths. Time-dependent numerical calculations of angle-dependent ionization yields for 1,2-dichloroethylene suggest that the harmonic spectra of molecular isomers reflect differences in their strong-field ionization. The subcycle ionization yields for the cis isomer are an order of magnitude higher than those for the trans isomer. The sensitivity in discrimination of the harmonic spectra of cis- and trans- isomers is greater than 8 and 5 for 1,2-dichloroethylene and 2-butene, respectively. We show that HHG spectroscopy cannot differentiate the harmonic spectra of the two enantiomers of the chiral molecule propylene oxide (C{sub 3}H{sub 6}O).

  20. Astaxanthin, canthaxanthin and astaxanthin esters in the copepod Acartia bifilosa (Copepoda, Calanoida during ontogenetic development

    Directory of Open Access Journals (Sweden)

    Maria £otocka

    2001-12-01

    Full Text Available The contents of astaxanthin, canthaxanthin and astaxanthin esters were studied in natural populations of the copepod Acartia bifilosa from the Pomeranian Bay and Gulf of Gdansk in the southern Baltic Sea. Samples dominated by any one of three developmental groups: (1 nauplii, (2 copepodids I-III and (3 copepodids IV-V and adults of Acartia bifilosa were analysed by means of high performance liquid chromatography (HPLC. As ontogenetic development progressed, significant changes occurred in the proportion of particular pigments in the total pigment pool of the various developmental groups. Astaxanthin and canthaxanthin occurred in all the groups, the former being clearly dominant. However, an increasing percentage of astaxanthin esters was recorded in the copepodids I-III, and even more in the copepodids IV-V and adults group. Most probably, astaxanthin is the main pigment active in copepod lipid metabolism. Carotenoid pigments in copepods very likely act as efficient free-electron quenchers and may be involved as antioxidants in rapid lipid metabolism. The exogenously feeding stages (late nauplii and copepodids transform plant carotenoids taken from food and are evidently capable of metabolising astaxanthin by esterification and further degradation. It is emphasised that, according to literature data, astaxanthin esters may have an even higher quenching ability. It is suggested that crustacean carotenoid pigments, with their electron donor-acceptor abilities, may replace oxygen in peroxidation processes connected with lipid metabolism. The consequences of such a physiological role of astaxanthin for present-day estimations of energy balances in zooplankton communities are mentioned.

  1. Free Radical Scavenging and Cellular Antioxidant Properties of Astaxanthin.

    Science.gov (United States)

    Dose, Janina; Matsugo, Seiichi; Yokokawa, Haruka; Koshida, Yutaro; Okazaki, Shigetoshi; Seidel, Ulrike; Eggersdorfer, Manfred; Rimbach, Gerald; Esatbeyoglu, Tuba

    2016-01-14

    Astaxanthin is a coloring agent which is used as a feed additive in aquaculture nutrition. Recently, potential health benefits of astaxanthin have been discussed which may be partly related to its free radical scavenging and antioxidant properties. Our electron spin resonance (ESR) and spin trapping data suggest that synthetic astaxanthin is a potent free radical scavenger in terms of diphenylpicryl-hydrazyl (DPPH) and galvinoxyl free radicals. Furthermore, astaxanthin dose-dependently quenched singlet oxygen as determined by photon counting. In addition to free radical scavenging and singlet oxygen quenching properties, astaxanthin induced the antioxidant enzyme paroxoanase-1, enhanced glutathione concentrations and prevented lipid peroxidation in cultured hepatocytes. Present results suggest that, beyond its coloring properties, synthetic astaxanthin exhibits free radical scavenging, singlet oxygen quenching, and antioxidant activities which could probably positively affect animal and human health.

  2. Free Radical Scavenging and Cellular Antioxidant Properties of Astaxanthin

    Directory of Open Access Journals (Sweden)

    Janina Dose

    2016-01-01

    Full Text Available Astaxanthin is a coloring agent which is used as a feed additive in aquaculture nutrition. Recently, potential health benefits of astaxanthin have been discussed which may be partly related to its free radical scavenging and antioxidant properties. Our electron spin resonance (ESR and spin trapping data suggest that synthetic astaxanthin is a potent free radical scavenger in terms of diphenylpicryl-hydrazyl (DPPH and galvinoxyl free radicals. Furthermore, astaxanthin dose-dependently quenched singlet oxygen as determined by photon counting. In addition to free radical scavenging and singlet oxygen quenching properties, astaxanthin induced the antioxidant enzyme paroxoanase-1, enhanced glutathione concentrations and prevented lipid peroxidation in cultured hepatocytes. Present results suggest that, beyond its coloring properties, synthetic astaxanthin exhibits free radical scavenging, singlet oxygen quenching, and antioxidant activities which could probably positively affect animal and human health.

  3. Xanthophyllomyces dendrorhous for the industrial production of astaxanthin.

    Science.gov (United States)

    Rodríguez-Sáiz, Marta; de la Fuente, Juan Luis; Barredo, José Luis

    2010-10-01

    Astaxanthin is a red xanthophyll (oxygenated carotenoid) with large importance in the aquaculture, pharmaceutical, and food industries. The green alga Haematococcus pluvialis and the heterobasidiomycetous yeast Xanthophyllomyces dendrorhous are currently known as the main microorganisms useful for astaxanthin production at the industrial scale. The improvement of astaxanthin titer by microbial fermentation is a requirement to be competitive with the synthetic manufacture by chemical procedures, which at present is the major source in the market. In this review, we show how the isolation of new strains of X. dendrorhous from the environment, the selection of mutants by the classical methods of random mutation and screening, and the rational metabolic engineering, have provided improved strains with higher astaxanthin productivity. To reduce production costs and enhance competitiveness from an industrial point of view, low-cost raw materials from industrial and agricultural origin have been adopted to get the maximal astaxanthin productivity. Finally, fermentation parameters have been studied in depth, both at flask and fermenter scales, to get maximal astaxanthin titers of 4.7 mg/g dry cell matter (420 mg/l) when X. dendrorhous was fermented under continuous white light. The industrial scale-up of this biotechnological process will provide a cost-effective method, alternative to synthetic astaxanthin, for the commercial exploitation of the expensive astaxanthin (about $2,500 per kilogram of pure astaxanthin).

  4. Chiral Graphene Quantum Dots.

    Science.gov (United States)

    Suzuki, Nozomu; Wang, Yichun; Elvati, Paolo; Qu, Zhi-Bei; Kim, Kyoungwon; Jiang, Shuang; Baumeister, Elizabeth; Lee, Jaewook; Yeom, Bongjun; Bahng, Joong Hwan; Lee, Jaebeom; Violi, Angela; Kotov, Nicholas A

    2016-02-23

    Chiral nanostructures from metals and semiconductors attract wide interest as components for polarization-enabled optoelectronic devices. Similarly to other fields of nanotechnology, graphene-based materials can greatly enrich physical and chemical phenomena associated with optical and electronic properties of chiral nanostructures and facilitate their applications in biology as well as other areas. Here, we report that covalent attachment of l/d-cysteine moieties to the edges of graphene quantum dots (GQDs) leads to their helical buckling due to chiral interactions at the "crowded" edges. Circular dichroism (CD) spectra of the GQDs revealed bands at ca. 210-220 and 250-265 nm that changed their signs for different chirality of the cysteine edge ligands. The high-energy chiroptical peaks at 210-220 nm correspond to the hybridized molecular orbitals involving the chiral center of amino acids and atoms of graphene edges. Diverse experimental and modeling data, including density functional theory calculations of CD spectra with probabilistic distribution of GQD isomers, indicate that the band at 250-265 nm originates from the three-dimensional twisting of the graphene sheet and can be attributed to the chiral excitonic transitions. The positive and negative low-energy CD bands correspond to the left and right helicity of GQDs, respectively. Exposure of liver HepG2 cells to L/D-GQDs reveals their general biocompatibility and a noticeable difference in the toxicity of the stereoisomers. Molecular dynamics simulations demonstrated that d-GQDs have a stronger tendency to accumulate within the cellular membrane than L-GQDs. Emergence of nanoscale chirality in GQDs decorated with biomolecules is expected to be a general stereochemical phenomenon for flexible sheets of nanomaterials.

  5. Electrochemical study of astaxanthin and astaxanthin n-octanoic monoester and diester: tendency to form radicals.

    Science.gov (United States)

    Focsan, A Ligia; Pan, Shanlin; Kispert, Lowell D

    2014-03-06

    The carotenoid astaxanthin known for its powerful antioxidant activity was electrochemically investigated along with the synthesized astaxanthin n-octanoic monoester and astaxanthin n-octanoic diester. Cyclic voltammograms (CVs) revealed a two-electron transfer oxidation for all three carotenoids with a difference in the two oxidation potentials (ΔE = E2(0) - E1(0)) slightly increasing from astaxanthin to the monoester to diester. Minimal or no exposure to water prevented the formation of carotenoid neutral radicals from dications and radical cations, causing near absence of the fifth peak in the CVs. This makes the CVs almost reversible and enables a more precise simulation of the redox potentials and the equilibrium constants for the formation of radical cations. The first oxidation potential (E1(0)) of 0.767₈, 0.773₈, and 0.775₃ V versus SCE and the second oxidation potential (E2(0)) of 0.982₈, 0.993₁, and 0.996₆ V versus SCE for astaxanthin, monoester, and diester, respectively, have been standardized to the potential of ferrocene of 0.528 V vs SCE given in a previous study. Reduction potentials (E3(0)) for formation of carotenoid neutral radicals from dications after proton loss from the three studied carotenoids are presented and compared to those of other carotenoids. According to our DFT calculations, the most favorable sites for deprotonation of radical cations and dications are found on the cyclohexene rings. These measurements provide insight into important properties of these carotenoids like radical scavenging of (•)OH, (•)CH3, and (•)OOH by proton abstraction from the carotenoid or the formation of carotenoid neutral radicals from radical cations which can quench photoexcited states. There is no essential difference in first oxidation potentials for the three carotenoids, which suggests a similar scavenging rate of the esters of astaxanthin toward (•)OH, (•)CH3, and (•)OOH radicals when compared to astaxanthin itself. The

  6. Discrimination of eight chloramphenicol isomers by liquid chromatography tandem mass spectrometry in order to investigate the natural occurence of chloramphenicol

    NARCIS (Netherlands)

    Berendsen, B.J.A.; Zuidema, T.; Jong, de J.; Stolker, A.A.M.; Nielen, M.W.F.

    2011-01-01

    This paper describes the discrimination of eight different isomers of chloramphenicol (CAP), an antibiotic banned for use in food producing animals, by reversed phase and chiral liquid chromatography in combination with tandem mass spectrometric detection. Previously, by liquid chromatography couple

  7. Enantioseparation of Dencichine and D-Isomer on L-Cysteine Derivative Phase by Ligand-exchange Chromatography

    Institute of Scientific and Technical Information of China (English)

    Yan Shun MA; Qing Hua MENG; Hong Yu SHI; Yuan De LONG; Tian Bao HUANG

    2006-01-01

    The enantioseparation of dencichine and its D-isomer was achieved on a novel chiral stationary phase via coating N-(2-hydroxyl-3-octoxyl) propyl-S-benzyl-(L)-cysteine on YWG-C18phase by ligand exchange chromatography.

  8. Nonlinear optics of astaxanthin thin films

    Science.gov (United States)

    Esser, A.; Fisch, Herbert; Haas, Karl-Heinz; Haedicke, E.; Paust, J.; Schrof, Wolfgang; Ticktin, Anton

    1993-02-01

    Carotinoids exhibit large nonlinear optical properties due to their extended (pi) -electron system. Compared to other polyenes which show a broad distribution of conjugation lengths, carotinoids exhibit a well defined molecular structure, i.e. a well defined conjugation length. Therefore the carotinoid molecules can serve as model compounds to study the relationship between structure and nonlinear optical properties. In this paper the synthesis of four astaxanthins with C-numbers ranging from 30 to 60, their preparation into thin films, wavelength dispersive Third Harmonic Generation (THG) measurements and some molecular modelling calculations will be presented. Resonant (chi) (3) values reach 1.2(DOT)10-10 esu for C60 astaxanthin. In the nonresonant regime a figure of merit (chi) (3)/(alpha) of several 10-13 esu-cm is demonstrated.

  9. Astaxanthin: a review of its chemistry and applications.

    Science.gov (United States)

    Higuera-Ciapara, I; Félix-Valenzuela, L; Goycoolea, F M

    2006-01-01

    Astaxanthin is a carotenoid widely used in salmonid and crustacean aquaculture to provide the pink color characteristic of that species. This application has been well documented for over two decades and is currently the major market driver for the pigment. Additionally, astaxanthin also plays a key role as an intermediary in reproductive processes. Synthetic astaxanthin dominates the world market but recent interest in natural sources of the pigment has increased substantially. Common sources of natural astaxanthin are the green algae Haematococcus pluvialis, the red yeast, Phaffia rhodozyma, as well as crustacean byproducts. Astaxanthin possesses an unusual antioxidant activity which has caused a surge in the nutraceutical market for the encapsulated product. Also, health benefits such as cardiovascular disease prevention, immune system boosting, bioactivity against Helycobacter pylori, and cataract prevention, have been associated with astaxanthin consumption. Research on the health benefits of astaxanthin is very recent and has mostly been performed in vitro or at the pre-clinical level with humans. This paper reviews the current available evidence regarding astaxanthin chemistry and its potential beneficial effects in humans.

  10. Spectrally resolved femtosecond photon echo spectroscopy of astaxanthin

    Science.gov (United States)

    Kumar, Ajitesh; Karthick Kumar, S. K.; Gupta, Aditya; Goswami, Debabrata

    2011-08-01

    We have studied the coherence and population dynamics of Astaxanthin solution in methanol and acetonitrile by spectrally resolving their photon echo signals. Our experiments indicate that methanol has a much stronger interaction with the ultrafast dynamics of Astaxanthin in comparison to that of acetonitrile.

  11. Development of safer molecules through chirality

    OpenAIRE

    Patil P; Kothekar M

    2006-01-01

    Many of the drugs currently used in medical practice are mixtures of enantiomers (racemates). Many a times, the two enantiomers differ in their pharmacokinetic and pharmacodynamic properties. Replacing existing racemates with single isomers has resulted in improved safety and/or efficacy profile of various racemates. In this review, pharmacokinetic and pharmacodynamic implications of chirality are discussed in brief, followed by an overview of some important chiral switches that have yielded ...

  12. In vitro plasma protein binding and aqueous aggregation behavior of astaxanthin dilysinate tetrahydrochloride.

    Science.gov (United States)

    Zsila, Ferenc; Fitos, Ilona; Bikádi, Zsolt; Simonyi, Miklós; Jackson, Henry L; Lockwood, Samuel F

    2004-11-01

    The tetrahydrochloride salt of astaxanthin di-L-lysinate (lys(2)AST) is a highly water-dispersible astaxanthin-amino acid conjugate, with an aqueous dispersibility of > or = 181.6 mg/mL. The statistical mixture of stereoisomers has been well characterized as an aqueous-phase superoxide anion scavenger, effective at micromolar (microM) concentrations. In the current study, the aqueous aggregation behavior and in vitro plasma protein binding [with fatty-acid-free human serum albumin (HSA) and alpha(1)-acid glycoprotein (AGP)] were investigated with a suite of techniques, including circular dichroism (CD) and UV-vis spectroscopy, ultrafiltration, competitive ligand displacement, and fluorescence quenching. Induced CD bands obtained in Ringer buffer solution of HSA demonstrated high affinity monomeric binding of the compound at low ligand per protein (L/P) ratios (in aqueous solution alone the carotenoid molecules formed card-pack aggregates). The binding constant ( approximately 10(6)M(-1)) and the binding stoichiometry (approximately 0.2 per albumin molecule) were calculated from CD titration data. CD displacement and ultrafiltration experiments performed with marker ligands of HSA indicated that the ligand binding occurred at a site distinct from the main drug binding sites of HSA (i.e., Sites I and II). At intermediate L/P ratios, both monomeric and aggregated ("chirally complexed") binding occurred simultaneously at distinct sites of the protein. At high L/P ratios, chiral complexation predominantly occurred on the asymmetric protein template. The tentative location of the chirally-complexed aggregation on the HSA template was identified as the large interdomain cleft of HSA, where carotenoid derivatives have been found to bind previously. Only weak binding to AGP was observed. These results suggest that parenteral use of this highly potent, water-dispersible astaxanthin-amino acid conjugate will result in plasma protein association, and plasma protein binding at

  13. Stability and changes in astaxanthin ester composition from Haematococcus pluvialis during storage

    Science.gov (United States)

    Miao, Fengping; Geng, Yahong; Lu, Dayan; Zuo, Jincheng; Li, Yeguang

    2013-11-01

    In this paper, we investigated the effects of temperature, oxygen, antioxidants, and corn germ oil on the stability of astaxanthin from Haematococcus pluvialis under different storage conditions, and changes in the composition of astaxanthin esters during storage using high performance liquid chromatography and spectrophotometry. Oxygen and high temperatures (22-25°C) significantly reduced the stability of astaxanthin esters. Corn germ oil and antioxidants (ascorbic acid and vitamin E) failed to protect astaxanthin from oxidation, and actually significantly increased the instability of astaxanthin. A change in the relative composition of astaxanthin esters was observed after 96 weeks of long-term storage. During storage, the relative amounts of free astaxanthin and astaxanthin monoesters declined, while the relative amount of astaxanthin diesters increased. Thus, the ratio of astaxanthin diester to monoester increased, and this ratio could be used to indicate if astaxanthin esters have been properly preserved. If the ratio is greater than 0.2, it suggests that the decrease in astaxanthin content could be higher than 20%. Our results show that storing algal powder from H. pluvialis or other natural astaxanthin products under vacuum and in the dark below 4°C is the most economical and applicable storage method for the large-scale production of astaxanthin from H. pluvialis. This storage method can produce an astaxanthin preservation rate of at least 80% after 96 weeks of storage.

  14. Astaxanthin synthesis by Xanthophyllomyces dendrorhous DSM 5626 and its astaxanthin overproducing mutants on xylose media under diferent illumination

    Directory of Open Access Journals (Sweden)

    Barbara Stachowiak

    2014-09-01

    Full Text Available Background. Astaxanthin is the most important and expensive carotenoid pigment used in aquaculture. Its commercial attractiveness is also related with its antioxidant potential. XanthophyUomyces dendrorhous yeast is considered to be promising for commercial production of astaxanthin. The aim of this study was to investigate the possibility of the growth and astaxanthin production by X. dendrorhous strains 011 media containing xylose under different illumination. Material and methods. A', dendrorhous DSM 5626 and its mutants: 10BE and 26UV were used in this study. The cultures were carried out 011 hydrolysed rye stillage (HS and YM medium with xylose (YM-K. Cell concentration, total carotenoid and astaxanthin yields were assessed in 5-day cultures. The effect of illumination in the range of 0-5.000 lx 011 growth and on astaxanthin production of yeasts in cultures run 011 YM-K medium was also examined. Results. For the tested yeast strains better growth parameters and astaxanthin yields were obtained on the YM-K medium. 011 which for all strains the highest pigment yields were recorded at 600-1.000 lx. The highest concentration of astaxanthin in cells was recorded for 26UV in a culture at 1.000 lx (0.51 gkg-1 DCW. The volume yield of the pigment regardless of strain was highest in cultures at 600 lx. In this case 10BE was found to be the best astaxanthin producer with a yield of 2.15 mg dm-3. Conclusions. Astaxanthin synthesis in X. dendrorhous DSM 5626 and its mutants was better 011 YM-K medium comparing to hydrolysed rye stillage. Moreover, carotenogenesis in the studied yeast strains was subjected to marked photoregulation. Illumination within the range of 600-1.000 lx promotes carotenogenesis and astaxanthin production, while exceeding a certain light capacity results in microbial cell death.

  15. Genome mining of astaxanthin biosynthetic genes from Sphingomonas sp. ATCC 55669 for heterologous overproduction in Escherichia coli

    OpenAIRE

    Ma, Tian; Zhou, Yuanjie; Li, Xiaowei; Zhu, Fayin; Cheng, Yongbo; Liu, Yi; Deng, Zixin; Liu, Tiangang

    2015-01-01

    Abstract As a highly valued keto‐carotenoid, astaxanthin is widely used in nutritional supplements and pharmaceuticals. Therefore, the demand for biosynthetic astaxanthin and improved efficiency of astaxanthin biosynthesis has driven the investigation of metabolic engineering of native astaxanthin producers and heterologous hosts. However, microbial resources for astaxanthin are limited. In this study, we found that the α‐Proteobacterium Sphingomonas sp. ATCC 55669 could produce astaxanthin n...

  16. GPC-HPLC法测定南极磷虾油中虾青素及校正因子计算%Determination of astaxanthin in antarctic krill oil by GPC-high performance liquid chromatography and calculation of correction factor

    Institute of Scientific and Technical Information of China (English)

    孙伟红; 冷凯良; 邢丽红; 朱敏; 翟毓秀; 苗均魁; 朱兰兰

    2013-01-01

    Taking health products, antarctic krill oil, as the object in the paper, an analytical method based on gel permeation chromatography-high performance liquid chromatography (GPC-HPLC ) has been developed for the determination of astaxanthin in antarctic krill oil. The sample was purified by gel permeation chromatography, saponified by sodium hydroxide-methanol solution, and separated by a C30 liquid chromatographic column. In this paper, we established the purification conditions of gel permeation chromatography, the collection time of astaxanthin and astaxanthin easter was 7. 48 ~ 12. 60 min. The conditions of saponification were researched by exploring the solvents, volume of sodium hydroxide-methanol solution and saponification time on saponification efficiency of astaxanthin in antarctic krill oil. The results show that methylene chloride: methanol as saponification solvent had the best effect than other solvents, the most suitable volume for 0. 2 mol/L sodium hydroxide-methanol solution was 1 mL, and the best saponification time was 12 h by comparing among 1~18h at 4℃. We also investigated the effect of pH on stability of astaxanthin in antarctic krill oil, the content of astaxanthin had less influence on neutral environment among 0 ~ 12 h, but the content in serious decline and isomerization on alkaline environment. The contents of isomers of astaxanthin in antarctic krill oil were calculated by calibration factor, the calibration factor of 13-cis-astaxanthin to trans-astaxanthin was 1.3, and 9-cis-astaxanthin to trans-astaxanthin was 1.1, so we got the quantitative method of astaxanthin in krill oil. The limits of quantification for astaxanthin in antarctic krill oil were 0. 5 mg/kg. There were good linear relationship between the chromatographic peak area and the concentration in the range of 0. 1 mg/L ~ 5 mg/L with correlation coefficient over 0.999. The average recoveries were between 96.0% and 98.5%, and the precision of the method were 3. 0% ~5. 6

  17. Accurate quantification of astaxanthin from Haematococcus crude extract spectrophotometrically

    Science.gov (United States)

    Li, Yeguang; Miao, Fengping; Geng, Yahong; Lu, Dayan; Zhang, Chengwu; Zeng, Mingtao

    2012-07-01

    The influence of alkali on astaxanthin and the optimal working wave length for measurement of astaxanthin from Haematococcus crude extract were investigated, and a spectrophotometric method for precise quantification of the astaxanthin based on the method of Boussiba et al. was established. According to Boussiba's method, alkali treatment destroys chlorophyll. However, we found that: 1) carotenoid content declined for about 25% in Haematococcus fresh cysts and up to 30% in dry powder of Haematococcus broken cysts after alkali treatment; and 2) dimethyl sulfoxide (DMSO)-extracted chlorophyll of green Haematococcus bares little absorption at 520-550 nm. Interestingly, a good linear relationship existed between absorbance at 530 nm and astaxanthin content, while an unknown interference at 540-550 nm was detected in our study. Therefore, with 530 nm as working wavelength, the alkali treatment to destroy chlorophyll was not necessary and the influence of chlorophyll, other carotenoids, and the unknown interference could be avoided. The astaxanthin contents of two samples were measured at 492 nm and 530 nm; the measured values at 530 nm were 2.617 g/100 g and 1.811 g/100 g. When compared with the measured values at 492 nm, the measured values at 530 nm decreased by 6.93% and 11.96%, respectively. The measured values at 530 nm are closer to the true astaxanthin contents in the samples. The data show that 530 nm is the most suitable wave length for spectrophotometric determination to the astaxanthin in Haematococcus crude extract.

  18. Multispectral Image Analysis for Robust Prediction of Astaxanthin Coating

    DEFF Research Database (Denmark)

    Ljungqvist, Martin Georg; Frosch, Stina; Nielsen, Michael Engelbrecht

    2013-01-01

    The aim of this study was to investigate the possibility of predicting the type and concentration level of astaxanthin coating of aquaculture feed pellets using multispectral image analysis. We used both natural and synthetic astaxanthin, and we used several different concentration levels...... of synthetic astaxanthin in combination with four different recipes of feed pellets. We used a VideometerLab with 20 spectral bands in the range of 385-1050 nm. We used linear discriminant analysis and sparse linear discriminant analysis for classification and variable selection. We used partial least squares...

  19. Chiral cardiovascular drugs: an overview.

    Science.gov (United States)

    Ranade, Vasant V; Somberg, John C

    2005-01-01

    Stereochemistry in drug molecules is rapidly becoming an important aspect in drug research, design, and development. Recently, individual stereoisomers of drug molecules with asymmetric centers such as fexofenadine, cetirizine, verapamil, fluoxetine, levalbutarol, and amphetamine, for example, have been separated and developed as individual drugs. These stereoisomers have different therapeutic activity, and each isomer has contributed differently with respect to its formulation's pharmacologic activity, side effects, and toxicity. The present overview discusses chirality among a select group of cardiovascular drugs, their stereochemical synthesis/preparation, isolation techniques using chiral chromatography, methods for confirmation of their enantiomeric purity, pharmacodynamics, and pharmacokinetics. Chirality has been visualized as an important factor in cardiovascular research. It is also becoming evident in other areas of therapeutics.

  20. Association of two single-isomer anionic CD in NACE for the chiral and achiral separation of fenbendazole, its sulphoxide and sulphone metabolites: application to their determination after in vitro metabolism.

    Science.gov (United States)

    Rousseau, Anne; Gillotin, Florian; Chiap, Patrice; Crommen, Jacques; Fillet, Marianne; Servais, Anne-Catherine

    2010-05-01

    A NACE method was developed for the separation of fenbendazole (FBZ), a prochiral drug giving rise to chiral (oxfendazole or OFZ) and nonchiral (FBZ sulphone or FBZSO(2)) metabolites. First, the effect of the nature and the concentration of CD as well as that of the acidic BGE on the enantiomeric separation of OFZ were studied. OFZ enantiomers were completely resolved using a BGE made up of 10 mM ammonium formate and 0.5 M TFA in methanol containing 10 mM heptakis(2,3-di-O-acetyl-6-O-sulfo)-beta-CD and 10 mM heptakis(2,3-di-O-methyl-6-O-sulfo)-beta-CD. Moreover, the NACE method was found to be particularly well suited to the simultaneous determination of FBZ, OFZ enantiomers, and FBZSO(2). Thiabendazole was selected as an internal standard. The CD-NACE potential was then evaluated for in vitro metabolism studies using FBZ as a model case. The OFZ enantiomers and FBZSO(2) could be detected after incubation of FBZ in the phenobarbital-induced male rat liver microsomes systems.

  1. Structure investigations on assembled astaxanthin molecules

    Science.gov (United States)

    Köpsel, Christian; Möltgen, Holger; Schuch, Horst; Auweter, Helmut; Kleinermanns, Karl; Martin, Hans-Dieter; Bettermann, Hans

    2005-08-01

    The carotenoid r,r-astaxanthin (3R,3‧R-dihydroxy-4,4‧-diketo-β-carotene) forms different types of aggregates in acetone-water mixtures. H-type aggregates were found in mixtures with a high part of water (e.g. 1:9 acetone-water mixture) whereas two different types of J-aggregates were identified in mixtures with a lower part of water (3:7 acetone-water mixture). These aggregates were characterized by recording UV/vis-absorption spectra, CD-spectra and fluorescence emissions. The sizes of the molecular assemblies were determined by dynamic light scattering experiments. The hydrodynamic diameter of the assemblies amounts 40 nm in 1:9 acetone-water mixtures and exceeds up to 1 μm in 3:7 acetone-water mixtures. Scanning tunneling microscopy monitored astaxanthin aggregates on graphite surfaces. The structure of the H-aggregate was obtained by molecular modeling calculations. The structure was confirmed by calculating the electronic absorption spectrum and the CD-spectrum where the molecular modeling structure was used as input.

  2. Astaxanthin as a Potential Neuroprotective Agent for Neurological Diseases.

    Science.gov (United States)

    Wu, Haijian; Niu, Huanjiang; Shao, Anwen; Wu, Cheng; Dixon, Brandon J; Zhang, Jianmin; Yang, Shuxu; Wang, Yirong

    2015-09-11

    Neurological diseases, which consist of acute injuries and chronic neurodegeneration, are the leading causes of human death and disability. However, the pathophysiology of these diseases have not been fully elucidated, and effective treatments are still lacking. Astaxanthin, a member of the xanthophyll group, is a red-orange carotenoid with unique cell membrane actions and diverse biological activities. More importantly, there is evidence demonstrating that astaxanthin confers neuroprotective effects in experimental models of acute injuries, chronic neurodegenerative disorders, and neurological diseases. The beneficial effects of astaxanthin are linked to its oxidative, anti-inflammatory, and anti-apoptotic characteristics. In this review, we will focus on the neuroprotective properties of astaxanthin and explore the underlying mechanisms in the setting of neurological diseases.

  3. Astaxanthin as a Potential Neuroprotective Agent for Neurological Diseases

    Directory of Open Access Journals (Sweden)

    Haijian Wu

    2015-09-01

    Full Text Available Neurological diseases, which consist of acute injuries and chronic neurodegeneration, are the leading causes of human death and disability. However, the pathophysiology of these diseases have not been fully elucidated, and effective treatments are still lacking. Astaxanthin, a member of the xanthophyll group, is a red-orange carotenoid with unique cell membrane actions and diverse biological activities. More importantly, there is evidence demonstrating that astaxanthin confers neuroprotective effects in experimental models of acute injuries, chronic neurodegenerative disorders, and neurological diseases. The beneficial effects of astaxanthin are linked to its oxidative, anti-inflammatory, and anti-apoptotic characteristics. In this review, we will focus on the neuroprotective properties of astaxanthin and explore the underlying mechanisms in the setting of neurological diseases.

  4. Citrus residues isolates improve astaxanthin production by Xanthophyllomyces dendrorhous.

    Science.gov (United States)

    Wu, Wei; Lu, Mingbo; Yu, Longjiang

    2010-01-01

    The wild strain and two astaxanthin-overproducing mutant strains, W618 and GNG274, of Xanthophyllomyces dendrorhous were analyzed in order to assess their ability to grow and synthesize astaxanthin in a minimal medium containing (per liter): 2 g KH2PO4, 0.5 g MgSO4, 2 g KNO3, and 1 g yeast extract, and supplemented with citrus residues isolates as a carbon source (citrus medium). The selected strain W618 was evaluated under various contents of citrus juice. At the content of 20% (v/v), the highest astaxanthin production reached 22.63 mg L(-1), which was two-fold more than that observed in yeast malt medium. Addition of 8% (v/v) n-hexadecane to the citrus medium was found to be optimal, increasing the astaxanthin yield by 21.7%.

  5. Chirality detection of enantiomers using twisted optical metamaterials

    Science.gov (United States)

    Zhao, Yang; Askarpour, Amir N.; Sun, Liuyang; Shi, Jinwei; Li, Xiaoqin; Alù, Andrea

    2017-01-01

    Many naturally occurring biomolecules, such as amino acids, sugars and nucleotides, are inherently chiral. Enantiomers, a pair of chiral isomers with opposite handedness, often exhibit similar physical and chemical properties due to their identical functional groups and composition, yet show different toxicity to cells. Detecting enantiomers in small quantities has an essential role in drug development to eliminate their unwanted side effects. Here we exploit strong chiral interactions with plasmonic metamaterials with specifically designed optical response to sense chiral molecules down to zeptomole levels, several orders of magnitude smaller than what is typically detectable with conventional circular dichroism spectroscopy. In particular, the measured spectra reveal opposite signs in the spectral regime directly associated with different chiral responses, providing a way to univocally assess molecular chirality. Our work introduces an ultrathin, planarized nanophotonic interface to sense chiral molecules with inherently weak circular dichroism at visible and near-infrared frequencies.

  6. Chiral photochemistry

    CERN Document Server

    Inoue, Yoshihisa

    2004-01-01

    Direct Asymmetric Photochemistry with Circularly Polarized Light, H. RauCoherent Laser Control of the Handedness of Chiral Molecules, P. Brumer and M. ShapiroMagnetochiral Anisotropy in Asymmetric Photochemistry, G.L.J.A.RikkenEnantiodifferentiating Photosensitized Reactions, Y. InoueDiastereodifferentiating Photoreactions, N. Hoffmann and J.-P. PeteChirality in Photochromism, Y. Yokoyama and M. SaitoChiral Photochemistry with Transition Metal Complexes, S. Sakaki and T. HamadaTemplate-Induced Enantioselective Photochemical Reactions in S

  7. Does the light influence astaxanthin production in Xanthophyllomyces dendrorhous?

    Science.gov (United States)

    Tropea, A; Gervasi, T; Melito, M R; Lo Curto, A; Lo Curto, R

    2013-04-01

    Astaxanthin (C40H52O4) is an important natural pigment that has considerable promising applications in human health. Until now, many efforts were made aimed to develop economically sustainable bioprocesses alternative to the chemical synthesis, to satisfy the increasing demand of this ketocarotenoid from feed, food and cosmetic industries. The extraction of natural astaxanthin from the yeast Xanthophyllomyces dendrorhous till now seems to be rather expensive if compared with chemically synthesized astaxanthin. In this article, astaxanthin production by Xanthophyllomyces dendrorhous under two different conditions was studied: a first effort was made using a conventional reactor while a second using an enlightened one. This research was aimed also to optimise astaxanthin production by testing the influence of the light and of some nutrient sources. From fermentation tests, an astaxanthin yield ranging about 970 µg g(-1) was obtained after fed batch cultivation in the conventional reactor. In the enlightened reactor lower values, about 930 µg g(-1), were found.

  8. Protective effects of astaxanthin from Paracoccus carotinifaciens on murine gastric ulcer models.

    Science.gov (United States)

    Murata, Kenta; Oyagi, Atsushi; Takahira, Dai; Tsuruma, Kazuhiro; Shimazawa, Masamitsu; Ishibashi, Takashi; Hara, Hideaki

    2012-08-01

    The purpose of this study was to investigate the effect of astaxanthin extracted from Paracoccus carotinifaciens on gastric mucosal damage in murine gastric ulcer models. Mice were pretreated with astaxanthin for 1 h before ulcer induction. Gastric ulcers were induced in mice by oral administration of hydrochloride (HCl)/ethanol or acidified aspirin. The effect of astaxanthin on lipid peroxidation in murine stomach homogenates was also evaluated by measuring the level of thiobarbituric acid reactive substance (TBARS). The free radical scavenging activities of astaxanthin were also measured by electron spin resonance (ESR) measurements. Astaxanthin significantly decreased the extent of HCl/ethanol- and acidified aspirin-induced gastric ulcers. Astaxanthin also decreased the level of TBARS. The ESR measurement showed that astaxanthin had radical scavenging activities against the 1,1-diphenyl-2-picrylhydrazyl radical and the superoxide anion radical. These results suggest that astaxanthin has antioxidant properties and exerts a protective effect against ulcer formation in murine models.

  9. Storage stability and antioxidant activity of complex of astaxanthin with hydroxypropyl-β-cyclodextrin.

    Science.gov (United States)

    Yuan, Chao; Du, Lei; Jin, Zhengyu; Xu, Xueming

    2013-01-02

    Storage stability of astaxanthin/hydroxypropyl-β-cyclodextrin (HPCD) inclusion complex was evaluated and which was compared with native astaxanthin. The storage stability of astaxanthin was enhanced after included in HPCD under 4 °C and 25 °C storage conditions. Antioxidant activity of astaxanthin/HPCD inclusion complex was also assayed using ascorbic acid as a control sample. The reducing power and DPPH radical scavenging activity of native astaxanthin were lower than ascorbic acid, while which of the complex were higher at low concentration for the good water solubility. The hydroxyl radical scavenging activities of astaxanthin and astaxanthin/HPCD complex far outclassed that of ascorbic acid, and the activity of the complex was a little lower than that of the native astaxanthin.

  10. Chemical stability of astaxanthin nanodispersions in orange juice and skimmed milk as model food systems.

    Science.gov (United States)

    Anarjan, Navideh; Tan, Chin Ping

    2013-08-15

    Solubilising astaxanthin in nanodispersion systems is a promising approach to incorporate astaxanthin into water-based food formulations. In this research, the chemical stabilities of astaxanthin nanodispersions diluted in orange juice and skimmed milk as model food systems and in deionised water as a control were evaluated. The nanodispersions displayed significantly (pastaxanthin degradation during storage. In vitro cellular uptake of astaxanthin from diluted astaxanthin nanodispersions in selected food systems was also evaluated. The cellular uptake of astaxanthin nanodispersions in skimmed milk was significantly higher (pastaxanthin nanodispersions in orange juice and deionised water. High in vitro cellular uptake of astaxanthin from the prepared astaxanthin nanodispersions can be achieved via incorporation into protein-based foods such as milk.

  11. Metabolic engineering of the astaxanthin-biosynthetic pathway of Xanthophyllomyces dendrorhous

    NARCIS (Netherlands)

    Visser, H.; Ooyen, van A.J.J.; Verdoes, J.C.

    2003-01-01

    This review describes the different approaches that have been used to manipulate and improve carotenoid production in Xanthophyllomyces dendrorhous. The red yeast X dendrorhous (formerly known as Phaffia rhodozyma) is one of the microbiological production systems for natural astaxanthin. Astaxanthin

  12. Selection of Astaxanthin-Overproducing Mutants of Phaffia rhodozyma with β-Ionone

    OpenAIRE

    Lewis, M. J.; Ragot, N.; Berlant, M. C.; Miranda, M.

    1990-01-01

    β-Ionone, an end ring analog of β-carotene, inhibits astaxanthin production in the red yeast Phaffia rhodozyma. Astaxanthin-overproducing mutants of this yeast are easily spotted on β-ionone-containing yeast malt agar plates. β-Ionone appears to block astaxanthin synthesis at the β-carotene level.

  13. 75 FR 5887 - Listing of Color Additives Exempt From Certification; Astaxanthin Dimethyldisuccinate...

    Science.gov (United States)

    2010-02-05

    ... Color Additives Exempt From Certification; Astaxanthin Dimethyldisuccinate; Confirmation of Effective... color additive regulations to provide for the safe use of astaxanthin dimethyldisuccinate as a color... astaxanthin dimethyldisuccinate as a color additive in the feed of salmonid fish to enhance the color of...

  14. Effect of carotenoid source and dietary lipid content on blood astaxanthin concentration in rainbow trout (Oncorhynchus mykiss)

    OpenAIRE

    Barbosa, M.J.; Morais, R.; Choubert, G.

    1999-01-01

    Astaxanthin concentration in the blood of rainbow trout was studied in a feeding trial with two different astaxanthin sources: green algae Haematococcus pluvialis and commercial beadlets of 8% astaxanthin content (CAROPHYLL® Pink), and two different dietary lipid levels. The green algae contained 1.4% of carotenoids on a dry matter basis: free astaxanthin (

  15. Chiral superconductors.

    Science.gov (United States)

    Kallin, Catherine; Berlinsky, John

    2016-05-01

    Chiral superconductivity is a striking quantum phenomenon in which an unconventional superconductor spontaneously develops an angular momentum and lowers its free energy by eliminating nodes in the gap. It is a topologically non-trivial state and, as such, exhibits distinctive topological modes at surfaces and defects. In this paper we discuss the current theory and experimental results on chiral superconductors, focusing on two of the best-studied systems, Sr2RuO4, which is thought to be a chiral triplet p-wave superconductor, and UPt3, which has two low-temperature superconducting phases (in zero magnetic field), the lower of which is believed to be chiral triplet f-wave. Other systems that may exhibit chiral superconductivity are also discussed. Key signatures of chiral superconductivity are surface currents and chiral Majorana modes, Majorana states in vortex cores, and the possibility of half-flux quantum vortices in the case of triplet pairing. Experimental evidence for chiral superconductivity from μSR, NMR, strain, polar Kerr effect and Josephson tunneling experiments are discussed.

  16. Accurate quantification of astaxanthin from Haematococcus crude extract spectrophotometrically

    Institute of Scientific and Technical Information of China (English)

    LI Yeguang; MIAO Fengping; GENG Yahong; LU Dayan; ZHANG Chengwu; ZENG Mingtao

    2012-01-01

    The influence of alkali on astaxanthin and the optimal working wave length for measurement of astaxanthin from Haematococcus crude extract were investigated,and a spectrophotometric method for precise quantification of the astaxanthin based on the method of Boussiba et al.was established.According to Boussiba's method,alkali treatment destroys chlorophyll.However,we found that:1) carotenoid content declined for about 25% in Haematococcus fresh cysts and up to 30% in dry powder of Haematococcus broken cysts after alkali treatment; and 2) dimethyl sulfoxide (DMSO)-extracted chlorophyll of green Haematococcus bares little absorption at 520-550 nm.Interestingly,a good linear relationship existed between absorbance at 530 nm and astaxanthin content,while an unknown interference at 540-550 nm was detected in our study.Therefore,with 530 nm as working wavelength,the alkali treatment to destroy chlorophyll was not necessary and the influence of chlorophyll,other carotenoids,and the unknown interference could be avoided.The astaxanthin contents of two samples were measured at 492 nm and 530 nm; the measured values at 530 nm were 2.617 g/100 g and 1.811 g/100 g.When compared with the measured values at 492 nm,the measured values at 530 nm decreased by 6.93% and 11.96%,respectively.The measured values at 530 nm are closer to the true astaxanthin contents in the samples.The data show that 530 nm is the most suitable wave length for spectrophotometric determination to the astaxanthin in Haematococcus crude extract.

  17. Development of safer molecules through chirality

    Directory of Open Access Journals (Sweden)

    Patil P

    2006-10-01

    Full Text Available Many of the drugs currently used in medical practice are mixtures of enantiomers (racemates. Many a times, the two enantiomers differ in their pharmacokinetic and pharmacodynamic properties. Replacing existing racemates with single isomers has resulted in improved safety and/or efficacy profile of various racemates. In this review, pharmacokinetic and pharmacodynamic implications of chirality are discussed in brief, followed by an overview of some important chiral switches that have yielded safer alternatives. These include levosalbutamol, S-ketamine, levobupivacaine, S-zopiclone, levocetirizine, S-amlodipine, S-atenolol, S-metoprolol, S-omeprazole, S-pantoprazole and R-ondansetron. Few potential chiral switches under evaluation and some chiral switches that have not been successful are also discussed.

  18. Effect of storage on oxidative quality and stability of extruded astaxanthin-coated fish feed pellets

    DEFF Research Database (Denmark)

    Dethlefsen, Markus Wied; Hjermitslev, Niels Harthøj; Frosch, Stina;

    2016-01-01

    This study examined the stability of extruded and astaxanthin-coated fish feed pellets during storage in a light box at 28°C and 620lx. Seven groups of fish feed pellets were vacuum coated with fish oil that contained levels of astaxanthin ranging from 0 to 100ppm. To equalize differences...... collected at storage day 8, 15, 22, 92 and 183 for chemical determination of the astaxanthin concentration. The degradation of astaxanthin was shown to primarily be affected by light and limited to occur at the surface of the fish feed pellets, whereas the astaxanthin embedded in the core of the pellets...

  19. Preparation of Astaxanthin Nanodispersions Using Gelatin-Based Stabilizer Systems

    Directory of Open Access Journals (Sweden)

    Navideh Anarjan

    2014-09-01

    Full Text Available The incorporation of lipophilic nutrients, such as astaxanthin (a fat soluble carotenoid in nanodispersion systems can either increase the water solubility, stability and bioavailability or widen their applications in aqueous food and pharmaceutical formulations. In this research, gelatin and its combinations with sucrose oleate as a small molecular emulsifier, sodium caseinate (SC as a protein and gum Arabic as a polysaccharide were used as stabilizer systems in the formation of astaxanthin nanodispersions via an emulsification-evaporation process. The results indicated that the addition of SC to gelatin in the stabilizer system could increase the chemical stability of astaxanthin nanodispersions significantly, while using a mixture of gelatin and sucrose oleate as a stabilizer led to production of nanodispersions with the smallest particle size (121.4 ± 8.6 nm. It was also shown that a combination of gelatin and gum Arabic could produce optimal astaxanthin nanodispersions in terms of physical stability (minimum polydispersity index (PDI and maximum zeta-potential. This study demonstrated that the mixture of surface active compounds showed higher emulsifying and stabilizing functionality compared to using them individually in the preparation of astaxanthin nanodispersions.

  20. Screening factors influencing the production of astaxanthin from freshwater and marine microalgae.

    Science.gov (United States)

    Binti Ibnu Rasid, Elda Nurafnie; Mohamad, Shaza Eva; Jamaluddin, Haryati; Salleh, Madihah Md

    2014-02-01

    Astaxanthin, a carotenoid pigment found in several aquatic organisms, is responsible for the red colour of salmon, trout and crustaceans. In this study, astaxanthin production from freshwater microalga Chlorella sorokiniana and marine microalga Tetraselmis sp. was investigated. Cell growth and astaxanthin production were determined spectrophotometrically at 620 and 480 nm, respectively. Astaxanthin was extracted using acetone and measured subsequent to biomass removal. Aerated conditions favoured astaxanthin production in C. sorokiniana, whereas Tetraselmis sp. was best cultured under unaerated conditions. C. sorokiniana produced more astaxanthin with the highest yield reached at 7.83 mg/l in 6.0 mM in nitrate containing medium compared to Tetraselmis sp. which recorded the highest yield of only 1.96 mg/l in 1.5 mM nitrate containing medium. Production in C. sorokiniana started at the early exponential phase, indicating that astaxanthin may be a growth-associated product in this microalga. Further optimization of astaxanthin production was performed using C. sorokiniana through a 2(3) full factorial experimental design, and a yield of 8.39 mg/l was achieved. Overall, the study has shown that both microalgae are capable of producing astaxanthin. Additionally, this research has highlighted C. sorokiniana as a potential astaxanthin producer that could serve as a natural astaxanthin source in the current market.

  1. Molecular mechanisms of the coordination between astaxanthin and fatty acid biosynthesis in Haematococcus pluvialis (Chlorophyceae).

    Science.gov (United States)

    Chen, Guanqun; Wang, Baobei; Han, Danxiang; Sommerfeld, Milton; Lu, Yinghua; Chen, Feng; Hu, Qiang

    2015-01-01

    Astaxanthin, a red ketocarotenoid with strong antioxidant activity and high commercial value, possesses important physiological functions in astaxanthin-producing microalgae. The green microalga Haematococcus pluvialis accumulates up to 4% fatty acid-esterified astaxanthin (by dry weight), and is used as a model species for exploring astaxanthin biosynthesis in unicellular photosynthetic organisms. Although coordination of astaxanthin and fatty acid biosynthesis in a stoichiometric fashion was observed in H. pluvialis, the interaction mechanism is unclear. Here we dissected the molecular mechanism underlying coordination between the two pathways in H. pluvialis. Our results eliminated possible coordination of this inter-dependence at the transcriptional level, and showed that this interaction was feedback-coordinated at the metabolite level. In vivo and in vitro experiments indicated that astaxanthin esterification drove the formation and accumulation of astaxanthin. We further showed that both free astaxanthin biosynthesis and esterification occurred in the endoplasmic reticulum, and that certain diacylglycerol acyltransferases may be the candidate enzymes catalyzing astaxanthin esterification. A model of astaxanthin biosynthesis in H. pluvialis was subsequently proposed. These findings provide further insights into astaxanthin biosynthesis in H. pluvialis.

  2. Improving the Stability of Astaxanthin by Microencapsulation in Calcium Alginate Beads

    Science.gov (United States)

    Lin, Shen-Fu; Chen, Ying-Chen; Chen, Ray-Neng; Chen, Ling-Chun; Ho, Hsiu-O; Tsung, Yu-Han; Sheu, Ming-Thau; Liu, Der-Zen

    2016-01-01

    There has been considerable interest in the biological functions of astaxanthin and its potential applications in the nutraceutical, cosmetics, food, and feed industries in recent years. However, the unstable structure of astaxanthin considerably limits its application. Therefore, this study reports the encapsulation of astaxanthin in calcium alginate beads using the extrusion method to improve its stability. This study also evaluates the stability of the encapsulated astaxanthin under different storage conditions. The evaluation of astaxanthin stability under various environmental factors reveals that temperature is the most influential environmental factor in astaxanthin degradation. Stability analysis shows that, regardless of the formulation used, the content of astaxanthin encapsulated in alginate beads remains above 90% of the original amount after 21 days of storage at 25°C. These results suggest that the proposed technique is a promising way to enhance the stability of other sensitive compounds. PMID:27093175

  3. The effective photoinduction of Haematococcus pluvialis for accumulating astaxanthin with attached cultivation.

    Science.gov (United States)

    Wan, Minxi; Hou, Dongmei; Li, Yuanguang; Fan, Jianhua; Huang, Jianke; Liang, Songtao; Wang, Weiliang; Pan, Ronghua; Wang, Jun; Li, Shulan

    2014-07-01

    As the optimal source of astaxanthin, Haematococcus pluvialis was cultured for commercial production of astaxanthin through two continuous phases: cell growth and astaxanthin induction. In this study, the efficiency of an attached system for producing astaxanthin from H. pluvialis was investigated and compared to that of the suspended system (bubble column bioreactor) under various conditions. Results showed that this attached system is more suitable for photoinduction of H. pluvialis than the suspended bioreactor. Under the optimal conditions, the astaxanthin productivity of the attached system was 65.8 mg m(-2)d(-1) and 2.4-fold of that in the suspended system. This attached approach also offers other advantages over suspended systems, such as, producing astaxanthin under a wide range of light intensities and temperatures, saving water, ease to harvest cells, resisting contamination. Therefore, the attached approach can be considered an economical, environmentally friendly and highly-efficient technology for producing astaxanthin from H. pluvialis.

  4. Improving the Stability of Astaxanthin by Microencapsulation in Calcium Alginate Beads.

    Science.gov (United States)

    Lin, Shen-Fu; Chen, Ying-Chen; Chen, Ray-Neng; Chen, Ling-Chun; Ho, Hsiu-O; Tsung, Yu-Han; Sheu, Ming-Thau; Liu, Der-Zen

    2016-01-01

    There has been considerable interest in the biological functions of astaxanthin and its potential applications in the nutraceutical, cosmetics, food, and feed industries in recent years. However, the unstable structure of astaxanthin considerably limits its application. Therefore, this study reports the encapsulation of astaxanthin in calcium alginate beads using the extrusion method to improve its stability. This study also evaluates the stability of the encapsulated astaxanthin under different storage conditions. The evaluation of astaxanthin stability under various environmental factors reveals that temperature is the most influential environmental factor in astaxanthin degradation. Stability analysis shows that, regardless of the formulation used, the content of astaxanthin encapsulated in alginate beads remains above 90% of the original amount after 21 days of storage at 25°C. These results suggest that the proposed technique is a promising way to enhance the stability of other sensitive compounds.

  5. Isotopic chirality

    Energy Technology Data Exchange (ETDEWEB)

    Floss, H.G. [Univ. of Washington, Seattle, WA (United States)

    1994-12-01

    This paper deals with compounds that are chiral-at least in part, due to isotope substitution-and their use in tracing the steric course of enzyme reaction in vitro and in vivo. There are other applications of isotopically chiral compounds (for example, in analyzing the steric course of nonenzymatic reactions and in probing the conformation of biomolecules) that are important but they will not be discussed in this context.

  6. Green Approaches to Extract Astaxanthin from Shrimp Waste

    DEFF Research Database (Denmark)

    Razi Parjikolaei, Behnaz; Errico, Massimiliano; El-Houri, Rime Bahij

    2016-01-01

    Sunflower oil and its methyl ester have recently been shown as potential green solvents which could substitute traditional organic solvents. This study investigates the economic feasibility of using these green solvents to extract astaxanthin from shrimp processing waste. The feasibility...... of commercial use of the green solvents under plausible process conditions is compared to extraction with a mixture of hexane: isopropanol. Process flowsheets describing these processes were created using SuperPro Designer. Although the astaxanthin extraction yield was highest when using hexane: isopropanol......, according to the economic analysis, the green solvents showed lower capital and operating costs. Extraction with methyl ester of sunflower oil was found to be the more efficient green solvent process investigated with respect to production rate and unit cost of concentrated astaxanthin (155 ppm)....

  7. Fatty acids attached to all-trans-astaxanthin alter its cis-trans equilibrium, and consequently its stability, upon light-accelerated autoxidation

    NARCIS (Netherlands)

    Bruijn, De Wouter J.C.; Weesepoel, Y.; Vincken, J.P.; Gruppen, H.

    2016-01-01

    Fatty acid esterification, common in naturally occurring astaxanthin, has been suggested to influence both colour stability and degradation of all-trans-astaxanthin. Therefore, astaxanthin stability was studied as influenced by monoesterification and diesterification with palmitate. Increased est

  8. Effect of Astaxanthin on Human Sperm Capacitation

    Directory of Open Access Journals (Sweden)

    Luciana Bordin

    2013-06-01

    Full Text Available In order to be able to fertilize oocytes, human sperm must undergo a series of morphological and structural alterations, known as capacitation. It has been shown that the production of endogenous sperm reactive oxygen species (ROS plays a key role in causing cells to undergo a massive acrosome reaction (AR. Astaxanthin (Asta, a photo-protective red pigment belonging to the carotenoid family, is recognized as having anti-oxidant, anti-cancer, anti-diabetic and anti-inflammatory properties and is present in many dietary supplements. This study evaluates the effect of Asta in a capacitating buffer which induces low ROS production and low percentages of acrosome-reacted cells (ARC. Sperm cells were incubated in the presence or absence of increasing concentrations of Asta or diamide (Diam and analyzed for their ROS production, Tyr-phosphorylation (Tyr-P pattern and percentages of ARC and non-viable cells (NVC. Results show that Asta ameliorated both sperm head Tyr-P and ARC values without affecting the ROS generation curve, whereas Diam succeeded in enhancing the Tyr-P level but only of the flagellum without increasing ARC values. It is suggested that Asta can be inserted in the membrane and therefore create capacitation-like membrane alteration which allow Tyr-P of the head. Once this has occurred, AR can take place and involves a higher numbers of cells.

  9. Astaxanthin: Sources, Extraction, Stability, Biological Activities and Its Commercial Applications—A Review

    Directory of Open Access Journals (Sweden)

    Ranga Rao Ambati

    2014-01-01

    Full Text Available There is currently much interest in biological active compounds derived from natural resources, especially compounds that can efficiently act on molecular targets, which are involved in various diseases. Astaxanthin (3,3′-dihydroxy-β, β′-carotene-4,4′-dione is a xanthophyll carotenoid, contained in Haematococcus pluvialis, Chlorella zofingiensis, Chlorococcum, and Phaffia rhodozyma. It accumulates up to 3.8% on the dry weight basis in H. pluvialis. Our recent published data on astaxanthin extraction, analysis, stability studies, and its biological activities results were added to this review paper. Based on our results and current literature, astaxanthin showed potential biological activity in in vitro and in vivo models. These studies emphasize the influence of astaxanthin and its beneficial effects on the metabolism in animals and humans. Bioavailability of astaxanthin in animals was enhanced after feeding Haematococcus biomass as a source of astaxanthin. Astaxanthin, used as a nutritional supplement, antioxidant and anticancer agent, prevents diabetes, cardiovascular diseases, and neurodegenerative disorders, and also stimulates immunization. Astaxanthin products are used for commercial applications in the dosage forms as tablets, capsules, syrups, oils, soft gels, creams, biomass and granulated powders. Astaxanthin patent applications are available in food, feed and nutraceutical applications. The current review provides up-to-date information on astaxanthin sources, extraction, analysis, stability, biological activities, health benefits and special attention paid to its commercial applications.

  10. The role of photorespiration during astaxanthin accumulation in Haematococcus pluvialis (Chlorophyceae).

    Science.gov (United States)

    Zhang, Chunhui; Zhang, Litao; Liu, Jianguo

    2016-10-01

    Most previous studies on Haematococcus pluvialis have been focused on growth and astaxanthin accumulation. However, the relationships between photorespiration and astaxanthin accumulation have not been clarified. The purpose of this study was to examine the role of photorespiration during the process of astaxanthin accumulation in H. pluvialis. During astaxanthin accumulation, the astaxanthin content was reduced significantly when photorespiration was inhibited by its specific inhibitor, carboxymethoxylamine. The inhibition of photorespiration did not change the dry weight, chlorophyll content and OJIP transients during the incubation; however, the inhibition of photorespiration significantly decreased the photochemistry of photosystem II and total photosynthetic O2 evolution capacity. Moreover, the restriction in photorespiration was synchronized with a decrease of astaxanthin accumulation. These results suggest that the photorespiratory pathway in H. pluvialis can accelerate astaxanthin accumulation. We speculate that photorespiration can enhance astaxanthin accumulation in the following ways: (i) photorespiration directly affects the glycerate-3-phosphate (PGA) level, which is intrinsically related to the accumulation of astaxanthin in H. pluvialis; (ii) the photorespiratory pathway indirectly affects the PGA level by effecting the dark reactions of photosynthesis, which then results in the enhancement of astaxanthin accumulation in H. pluvialis.

  11. Astaxanthin: sources, extraction, stability, biological activities and its commercial applications--a review.

    Science.gov (United States)

    Ambati, Ranga Rao; Phang, Siew Moi; Ravi, Sarada; Aswathanarayana, Ravishankar Gokare

    2014-01-07

    There is currently much interest in biological active compounds derived from natural resources, especially compounds that can efficiently act on molecular targets, which are involved in various diseases. Astaxanthin (3,3'-dihydroxy-β, β'-carotene-4,4'-dione) is a xanthophyll carotenoid, contained in Haematococcus pluvialis, Chlorella zofingiensis, Chlorococcum, and Phaffia rhodozyma. It accumulates up to 3.8% on the dry weight basis in H. pluvialis. Our recent published data on astaxanthin extraction, analysis, stability studies, and its biological activities results were added to this review paper. Based on our results and current literature, astaxanthin showed potential biological activity in in vitro and in vivo models. These studies emphasize the influence of astaxanthin and its beneficial effects on the metabolism in animals and humans. Bioavailability of astaxanthin in animals was enhanced after feeding Haematococcus biomass as a source of astaxanthin. Astaxanthin, used as a nutritional supplement, antioxidant and anticancer agent, prevents diabetes, cardiovascular diseases, and neurodegenerative disorders, and also stimulates immunization. Astaxanthin products are used for commercial applications in the dosage forms as tablets, capsules, syrups, oils, soft gels, creams, biomass and granulated powders. Astaxanthin patent applications are available in food, feed and nutraceutical applications. The current review provides up-to-date information on astaxanthin sources, extraction, analysis, stability, biological activities, health benefits and special attention paid to its commercial applications.

  12. Isomer Energy System Design Concepts

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, D

    2003-09-01

    Isomer energy supplies offer the potential to increase the output power over time to accommodate varying power needs. Other materials with similar energy density (for example isotopic energy sources such as {sup 238}Pu) do not offer the potential to increase power with time. Often the design life of an energy source is significant when compared to the half-life of the isotope. As a result, the conventional isotopic energy supplies operate with significant excess power at start of life to meet the power needs at end-of-life. For example a {sup 238}Pu radioisotope energy supply with a 35-year design life must account for radioactive decay losses of about 25% of the plutonium present at the start of life. This decay loss is significant if the required output power from the device is constant with time. If the required power output from the device increases with time (such as some space applications), significant increases in power supply weight are required to meet design power requirements. Isomer energy supplies offer the potential to increase the output power over time to meet varying power needs, thereby offering a significant advantage over conventional systems. Isomer energy supplies also offer the possibility of being ''turned on'' based on need at a specific time. These characteristics offer distinct advantages to isomer energy supplies. This report examines the basic engineering characteristics of a hypothetical isomer energy supply in order to gain insight into properties of isomers that will make them potentially useful as energy sources in engineered systems. These isomer properties provide a basis for identification of candidate isomers and provide a basis for an isomer search.

  13. Enantiomers of a nonylphenol isomer: absolute configurations and estrogenic potencies.

    Science.gov (United States)

    Zhang, Haifeng; Oppel, Iris M; Spiteller, Michael; Guenther, Klaus; Boehmler, Gabriele; Zuehlke, Sebastian

    2009-02-01

    Enantiomers of 4-(1,1,2-trimethylhexyl)phenol, a chiral isomer of the endocrine disrupting chemical nonylphenol, have been resolved and isolated by preparative chiral HPLC. The absolute configurations of the enantiomers were then determined by an X-ray crystallographic study of the (-)-camphanoyl derivative of the first eluted enantiomer NP(35)E1. The first enantiomer (NP(35)E1) and the second enantiomer (NP(35)E2) eluted were found to have the S and R absolute configurations, respectively. The estrogenic potencies of the S and R enantiomers were tested by the E-screen assay. A slight difference was observed in the relative proliferative effect between the S enantiomer and R enantiomer in the E-screen assay.

  14. Multi-spectral Image Analysis for Astaxanthin Coating Classification

    DEFF Research Database (Denmark)

    Ljungqvist, Martin Georg; Ersbøll, Bjarne Kjær; Nielsen, Michael Engelbrecht

    2011-01-01

    Industrial quality inspection using image analysis on astaxanthin coating in aquaculture feed pellets is of great importance for automatic production control. In this study multi-spectral image analysis of pellets was performed using LDA, QDA, SNV and PCA on pixel level and mean value of pixels f...

  15. Kinetic model for astaxanthin aggregation in water-methanol mixtures

    Science.gov (United States)

    Giovannetti, Rita; Alibabaei, Leila; Pucciarelli, Filippo

    2009-07-01

    The aggregation of astaxanthin in hydrated methanol was kinetically studied in the temperature range from 10 °C to 50 °C, at different astaxanthin concentrations and solvent composition. A kinetic model for the formation and transformation of astaxanthin aggregated has been proposed. Spectrophotometric studies showed that monomeric astaxanthin decayed to H-aggregates that after-wards formed J-aggregates when water content was 50% and the temperature lower than 20 °C; at higher temperatures, very stable J-aggregates were formed directly. Monomer formed very stable H-aggregates when the water content was greater than 60%; in these conditions H-aggregates decayed into J-aggregates only when the temperature was at least 50 °C. Through these findings it was possible to establish that the aggregation reactions took place through a two steps consecutive reaction with first order kinetic constants and that the values of these depended on the solvent composition and temperature.

  16. Efficient transformation of the astaxanthin-producing yeast Phaffia rhodozyma.

    NARCIS (Netherlands)

    Wery, J.; Verdoes, J.C.; Ooyen, van A.J.J.

    1998-01-01

    An efficient transformation system for the astaxanthin-producing yeast Phaffia rhodozyma was developed based on electroporation that routinely yields approximately 1000 transformants per g of plasmid DNA. The high transformation efficiency depends on vector integration in the ribosomal DNA (rDNA) an

  17. Chiral Nanoscience and Nanotechnology

    OpenAIRE

    Dibyendu S. Bag; T.C. Shami; K.U. Bhasker Rao

    2008-01-01

    The paper reviews nanoscale science and technology of chiral molecules/macromolecules-under twosubtopics-chiral nanotechnology and nano-chiral technology. Chiral nanotechnology discusses thenanotechnology, where molecular chirality plays a role in the properties of materials, including molecularswitches, molecular motors, and other molecular devices; chiral supramolecules and self-assembled nanotubesand their functions are also highlighted. Nano-chiral technology  describes the nanoscale appr...

  18. Oxidative stress and astaxanthin: The novel supernutrient carotenoid

    Directory of Open Access Journals (Sweden)

    Sasmita Biswal

    2014-01-01

    Full Text Available Background: Oxidative stress and inflammation leads to, generation and overproduction of the reactive oxygen species and reactive nitrogen species and hence are responsible for many diseases such as Alzheimer′s disease, Parkinson′s disease, diabetes mellitus, rheumatoid arthritis, and neurodegenerative motor neuron diseases. Antioxidants are found in varying amounts in vegetables, fruits, grain cereals, eggs, meat, legumes and nuts. However, there is always a search for antioxidants that can quench and breakup the chain of generation of free-radicals. Aims: Astaxanthin, a ketocarotenoid, has exceptional antioxidant activity and hence can be used for prevention of cardiovascular diseases, inflammatory and neurodegenerative diseases, boosting of the immune system, anti-Helicobacter pylori activity, and cataract prevention. Hence, an attempt has performed in this review to compile data on astaxanthin and its several diverse applications over the last decade with an aim to escalate the intense interest in undertaking new research on this natural fascinating molecule. Materials and Methods: A literature search using astaxanthin and antioxidants as keywords using Google as the search engine was done and the data obtained were compiled and presented. Results and Conclusions: Astaxanthin can be a great supplement for everyone in enhancing immunity, preventing a myriad of diseases in our hectic lifestyle by providing more energy, reducing oxidative damage, producing clarity of vision as well as protection from the harmful ultraviolet rays of the sun! Further the immunomodulatory, antioxidative, and antiinflammatory activity of astaxanthin a bioactive natural supernutrient carotenoid may be very important to human health in treating many such untreatable diseases.

  19. Isomer Spectrum of Small Carbon Clusters

    Institute of Scientific and Technical Information of China (English)

    SHENG Yang; LI Peng; NING Xi-Jing

    2004-01-01

    A theoretical method is developed to find isomers of cluster particles, and the isomer spectrum of carbon clusters Cn (n = 3-44) is obtained. It is found that the isomers of 3-11 atoms are in either mono-ring or line shapes,while the isomers of 12-18 atoms show flat sheet shapes. As cluster size increases, bowl isomers become more (n > 19) until cage isomers dominate the structures (n > 27). Based on the isomer spectrum, results of a previous experiment are interpreted.

  20. On Chiral Space Groups and Chiral Molecules

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    This note explains the relationship (as well as the absence of a relationship) between chiral space groups and chiral molecules (which have absolute configurations). For a chiral molecule, which must crystallize in a chiral space group, the outcome of the absolute configuration determination must be linked to some other properties of the chiral crystal such as its optical activity for the observation to the relevant.

  1. On Chiral Space Groups and Chiral Molecules

    Institute of Scientific and Technical Information of China (English)

    NgSeikWng; HUSheng-Zhi

    2003-01-01

    This note explains the relationship (as well as the absence of a relationship) between chiral space groups and chiral molecules (which have absolute configurations).For a chiral molecule,which must crystallize in a chiral space group,the outcome of the absolute configuration determination must be linked to some other properties of the chiral crystal such as its optical activity for the observation to the relevant.

  2. Astaxanthin Accumulation in the Green Alga Haematococcus pluvialis: Effects of Cultivation Parameters

    Institute of Scientific and Technical Information of China (English)

    Ping He; James Duncan; James Barber

    2007-01-01

    The green alga, Haematococcus pluvialis Flotow is used as a source of the ketocarotenoid astaxanthin for application in fish aquaculture, pharmaceutical and cosmetic industries. Cells of the green alga were induced by the application of different light and starvation conditions to evaluate the effect in astaxanthin accumulate. The condiphosphate starvation. The results show that stresses applied in culture, which interfere with cell division, trigger the accumulation of astaxanthin. Notably, sulfur starvation results in a massive accumulation of this commercially important carotenoid.

  3. Astaxanthin Synthesis by Yeast Xanthophyllomyces dendrorhous and its Mutants on Media Based on Plant Extracts.

    Science.gov (United States)

    Stachowiak, Barbara

    2012-12-01

    The study evaluated the effect of media based on plant extracts: potato, carrot and barley malt broth, on growth and astaxanthin synthesis by yeast Xanthophyllomyces dendrorhous DSM 5626 and its mutants. The carrot medium promoted carotenogenesis most effectively. In cultures on this medium the highest volumetric and cellular concentrations of astaxanthin were recorded for four out of five tested strains. Also the share of astaxanthin in the total carotenoids produced by the tested strains was the highest.

  4. Astaxanthin Synthesis by Yeast Xanthophyllomyces dendrorhous and its Mutants on Media Based on Plant Extracts

    OpenAIRE

    Stachowiak, Barbara

    2012-01-01

    The study evaluated the effect of media based on plant extracts: potato, carrot and barley malt broth, on growth and astaxanthin synthesis by yeast Xanthophyllomyces dendrorhous DSM 5626 and its mutants. The carrot medium promoted carotenogenesis most effectively. In cultures on this medium the highest volumetric and cellular concentrations of astaxanthin were recorded for four out of five tested strains. Also the share of astaxanthin in the total carotenoids produced by the tested strains wa...

  5. Determination of astaxanthin concentration in Rainbow trout (Oncorhynchus mykiss) by multispectral image analysis

    DEFF Research Database (Denmark)

    Frosch, Stina; Dissing, Bjørn Skovlund; Ersbøll, Bjarne Kjær

    extraction of astaxanthin from the minced sample into a suitable solvent such as acetone or hexane before further analysis. The existing methods have several drawbacks including being destructive and labour consuming. Current state-of-the art vision systems for quality and process control in the fish.......27 ppm and a goodness of fit of 0.86. The PLSR model made it possible to predict the astaxanthin concentration in each pixel of the image – surface chemistry map - and thereby show the astaxanthin distribution in the fillet. The projected images clearly show a difference in astaxanthin distribution...

  6. Chiral Separation by Capillary Zone Electrophoresis Used Cyclodextrins and Their Derivatives as Chiral Selector

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Capillary zone electrophoresis (CZE) is a very pronising analytical technique for the optical isomer resolution of the compounds studied. The drawbacks of the techniques such as HPLC [1] were sophisticated stationary phases and/or the relatively high quantity of the chiral agent in the mobile phase, which do not exist in CZE. The capillary electrophoresis (CE) method can offer advantages on lower consumption of analyte and background electrolyte (BGE), shorter analysis time, and higher efficiencies [2-3

  7. Genome mining of astaxanthin biosynthetic genes from Sphingomonas sp. ATCC 55669 for heterologous overproduction in Escherichia coli.

    Science.gov (United States)

    Ma, Tian; Zhou, Yuanjie; Li, Xiaowei; Zhu, Fayin; Cheng, Yongbo; Liu, Yi; Deng, Zixin; Liu, Tiangang

    2016-02-01

    As a highly valued keto-carotenoid, astaxanthin is widely used in nutritional supplements and pharmaceuticals. Therefore, the demand for biosynthetic astaxanthin and improved efficiency of astaxanthin biosynthesis has driven the investigation of metabolic engineering of native astaxanthin producers and heterologous hosts. However, microbial resources for astaxanthin are limited. In this study, we found that the α-Proteobacterium Sphingomonas sp. ATCC 55669 could produce astaxanthin naturally. We used whole-genome sequencing to identify the astaxanthin biosynthetic pathway using a combined PacBio-Illumina approach. The putative astaxanthin biosynthetic pathway in Sphingomonas sp. ATCC 55669 was predicted. For further confirmation, a high-efficiency targeted engineering carotenoid synthesis platform was constructed in E. coli for identifying the functional roles of candidate genes. All genes involved in astaxanthin biosynthesis showed discrete distributions on the chromosome. Moreover, the overexpression of exogenous E. coli idi in Sphingomonas sp. ATCC 55669 increased astaxanthin production by 5.4-fold. This study described a new astaxanthin producer and provided more biosynthesis components for bioengineering of astaxanthin in the future.

  8. Stegosaurus chirality

    OpenAIRE

    Cameron, R.P.; Cameron, J. A.; Barnett, S. M.

    2016-01-01

    We explain that Stegosaurus exhibited exterior chirality and observe that the largest plate in particular of USNM 4394, USNM 4714, DMNS 2818 and NHMUK R36730 appears to have tilted to the right rather than to the left in each case. Several instances in which Stegosaurus specimens have been confused with their distinct, hypothetical mirror-image forms are highlighted. We believe our findings to be consistent with the hypothesis that Stegosaurus's plates acted primarily as display structures. A...

  9. Adsorption equilibria of dimethylnaphthalene isomers

    Energy Technology Data Exchange (ETDEWEB)

    Rota, R.; Morbidelli, M. [Politecnico di Milano (Italy). Dipt. di Chimica Fisica Applicata; Rombi, E.; Monaci, R.; Ferino, I.; Solinas, V. [Univ. di Cagliari (Italy). Dipt. di Scienze Chimiche

    1996-01-01

    Commercial sources of DMNs are the aromatic petroleum fraction of the appropriate boiling range and the coal liquefaction products. Adsorption processes for separating mixtures of dimethylnaphthalene (DMN) isomers are of potential interest for the production of 2,6-DMN. In this work, the adsorption equilibria of liquid mixtures of DMN isomers on zeolites have been investigated experimentally. The separation factors between the various isomers have been found to depend strongly on the composition of the fluid phase. A suitable equilibrium model, based on the adsorbed solution theory, has been developed to describe the multicomponent adsorption equilibria in the entire range of interest. Its performance has been tested using binary and ternary equilibrium data.

  10. Optimization of acidic extraction of astaxanthin from Phaffia rhodozyma

    Institute of Scientific and Technical Information of China (English)

    Hui NI; Qi-he CHEN; Guo-qing HE; Guang-bin WU; Yuan-fan YANG

    2008-01-01

    Optimization of a process for extracting astaxanthin from Phaffia rhodozyma by acidic method was investigated,regarding several extraction factors such as acids, organic solvents, temperature and time. Fractional factorial design, central composite design and response surface methodology were used to derive a statistically optimal model, which corresponded to the following optimal condition: concentration of lactic acid at 5.55 mol/L, ratio of ethanol to yeast dry weight at 20.25 ml/g, temperature for cell-disruption at 30 ℃, and extraction time for 3 min. Under this condition, astaxanthin and the total carotenoids could be extracted in amounts of 1294.7 μg/g and 1516.0 μg/g, respectively. This acidic method has advantages such as high extraction efficiency, low chemical toxicity and no special requirement of instruments. Therefore, it might be a more feasible and practical method for industrial practice.

  11. Putative benefits of microalgal astaxanthin on exercise and human health

    OpenAIRE

    Barros, Marcelo P; Sandra C. Poppe; Tácito P. Souza-Junior

    2011-01-01

    Astaxanthin (ASTA) is a pinkish-orange carotenoid produced by microalgae, but also commonly found in shrimp, lobster and salmon, which accumulate ASTA from the aquatic food chain. Numerous studies have addressed the benefits of ASTA for human health, including the inhibition of LDL oxidation, UV-photoprotection and prophylaxis of bacterial stomach ulcers. ASTA is recognized as a powerful scavenger of reactive oxygen species (ROS), especially those involved in lipid peroxidation. Both aerobic ...

  12. Astaxanthin decreased oxidative stress and inflammation and enhanced immune response in humans

    Directory of Open Access Journals (Sweden)

    Line Larry L

    2010-03-01

    Full Text Available Abstract Background Astaxanthin modulates immune response, inhibits cancer cell growth, reduces bacterial load and gastric inflammation, and protects against UVA-induced oxidative stress in in vitro and rodent models. Similar clinical studies in humans are unavailable. Our objective is to study the action of dietary astaxanthin in modulating immune response, oxidative status and inflammation in young healthy adult female human subjects. Methods Participants (averaged 21.5 yr received 0, 2, or 8 mg astaxanthin (n = 14/diet daily for 8 wk in a randomized double-blind, placebo-controlled study. Immune response was assessed on wk 0, 4 and 8, and tuberculin test performed on wk 8. Results Plasma astaxanthin increased (P helper, Tcytotoxic or natural killer cells. A higher percentage of leukocytes expressed the LFA-1 marker in subjects given 2 mg astaxanthin on wk 8. Subjects fed 2 mg astaxanthin had a higher tuberculin response than unsupplemented subjects. There was no difference in TNF and IL-2 concentrations, but plasma IFN-γ and IL-6 increased on wk 8 in subjects given 8 mg astaxanthin. Conclusion Therefore, dietary astaxanthin decreases a DNA damage biomarker and acute phase protein, and enhances immune response in young healthy females.

  13. Astaxanthin production by freshwater microalgae Chlorella sorokiniana and marine microalgae Tetraselmis sp.

    Science.gov (United States)

    Raman, Rinugah; Mohamad, Shaza Eva

    2012-12-15

    There are numerous commercial applications of microalgae nowadays owing to their vast biotechnological and economical potential. Indisputably, astaxanthin is one of the high value product synthesized by microalgae and is achieving commercial success. Astaxanthin is a keto-carotenoid pigment found in many aquatic animals including microalgae. Astaxanthin cannot be synthesized by animals and provided in the diet is compulsory. In this study, the production of astaxanthin by the freshwater microalgae Chlorella sorokiniana and marine microalgae Tetraselmis sp. were studied. The relationship between growth and astaxanthin production by marine and freshwater microalgae cultivated under various carbon sources and concentrations, environmental conditions and nitrate concentrations was investigated in this study. Inorganic carbon source and low nitrate concentration favored the growth and production of astaxanthin by the marine microalgae Tetraselmis sp. and the freshwater microalgae Chlorella sorokiniana. Outdoor cultivation enhanced the growth of microalgae, while indoor cultivation promoted the formation of astaxanthin. The results indicated that supplementation of light, inorganic carbon and nitrate could be effectively manipulated to enhance the production of astaxanthin by both microalgae studied.

  14. Production of astaxanthin from cellulosic biomass sugars by mutants of the yeast Phaffia rhodozyma

    Science.gov (United States)

    Astaxanthin is a carotenoid of high value to the aquaculture, nutraceutical, and pharmaceutical industries. Three mutant strains of the astaxanthin-producing yeast Phaffia rhodozyma, which were derived from the parent strain ATCC 24202 (UCD 67-210) and designated JTM166, JTM185, and SSM19, were test...

  15. [Kinetic model for optimal feeding strategy in astaxanthin production by Xanthophyllomyces dendrorhous].

    Science.gov (United States)

    Lu, Mingbo; Ji, Lei; Liu, Yongsheng; Zhou, Pengpeng; Yu, Longjiang

    2008-11-01

    Astaxanthin is a useful pigmentation source in fish aquaculture. It has strong antioxidative activity and therefore has potential application in delaying aging and degenerative diseases in human and animals. In recent years, there is a growing demand for astaxanthin. The red yeast Xanthophyllomyces dendrorhous (called Phaffia rhodozyma before) is one of the most promising microorganisms for the commercial production of astaxanthin. During fermentation, X. dendrorhous shows the Crabtree effect. Higher glucose concentration will cause significant reductions in biomass and astaxanthin production. Therefore, fed-batch processes are particularly useful. In this paper, effects of glucose-feeding strategies on astaxanthin production by X. dendrorhous were studied. Based on the substrate inhibition model, an optimized two-stage feeding strategy for astaxanthin production of high-cell-density fermentation was proposed. Glucose concentration was first controlled at about 25 g/L during the lag phase and the early exponential phase. In such case, biomass could reach its maximum value in relatively short time. Then the glucose concentration was controlled at about 5 g/L in the later exponential phase and stationary phase. The synthesis of astaxanthin could be effectively prolonged. The results showed that the optimized two-stage feeding strategy was the best among all the feeding strategies, and could obtain the highest biomass (23.8 g/L) and astaxanthin production (29.05 mg/L), which was a significant increase (52.8% and 109% respectively) compared with a batch process.

  16. Efficient screening for astaxanthin-overproducing mutants of the yeast Xanthophyllomyces dendrorhous by flow cytometry.

    Science.gov (United States)

    Ukibe, Ken; Katsuragi, Tohoru; Tani, Yoshiki; Takagi, Hiroshi

    2008-09-01

    Astaxanthin possesses higher antioxidant activity than other carotenoids and, for this and other reasons, has great commercial potential for use in the aquaculture, pharmaceutical, and food industries. The basidiomycetous yeast Xanthophyllomyces dendrorhous is one of the best natural producers of astaxanthin, but wild-type cells accumulate only a small amount of astaxanthin. In this study, we developed an efficient flow cytometry method to screen for astaxanthin-overproducing mutants of X. dendrorhous. We first examined the relationship between cellular astaxanthin content and the intensity of fluorescence emitted from the cell. Although the fluorescence emission maximum of astaxanthin dissolved in acetone occurred at 570 nm, intracellular astaxanthin content correlated better with emission at around 675 nm in different X. dendrorhous strains. Using this emission wavelength, we screened cells mutagenized with ethyl methanesulfonate and successfully isolated mutants that produced 1.5-3.8-fold more astaxanthin than parent cells. This method enabled us to obtain overproducers five times more efficient than conventional screening from plate culture.

  17. High-level production of astaxanthin by Xanthophyllomyces dendrorhous mutant JH1 using statistical experimental designs.

    Science.gov (United States)

    Kim, Jeong-Hwan; Kang, Seong-Woo; Kim, Seung-Wook; Chang, Hyo-Ihl

    2005-09-01

    Medium composition was optimized for high-level production of astaxanthin by Xanthophyllomyces dendrorhous mutant JH1 using statistical experimental designs. Glucose and yeast extract were the most important factors affecting astaxanthin production. Glucose 3.89%, yeast extract 0.29%, KH2PO4 0.25%, MgSO4 0.05%, MnSO4 0.02%, and CaCl2 0.01% were optimum for high-level production of astaxanthin. Under optimized conditions, the maximum concentration of astaxanthin obtained after 7 d of cultivation was 36.06 mg/l. The concentration of astaxanthin predicted by a polynomial model was 36.16 mg/l.

  18. Effect of Different Carbon Source on Expression of Carotenogenic Genes and Astaxanthin Production in Xanthophyllomyces dendrorhous

    Directory of Open Access Journals (Sweden)

    Wei Wu

    2013-10-01

    Full Text Available The present research gives an insight into astaxanthin production, as well as transcription differences of four key carotenogenic genes, in Xanthophyllomyces dendrorhous when cultured with various carbon sources and soybean oil as co-substrates. Glucose was found to be the carbon source with best culture growth and astaxanthin production and the addition of 2% (v/v soybean oil resulted in even higher astaxanthin producing. In addition, four carotenogenic genes encoding geranylgeranyl diphosphate synthase (crtE, phytoene desaturase (crtl, phytoene synthase lycopene cyclase(crtYB, and astaxanthin synthetase (ast, respectively, were demonstrated to be associated with different transcription levels under various substrates. The present study suggests the effectiveness of manipulating the metabolic regulation by using different carbon sources, in order to improve the production of astaxanthin.

  19. Characterization and performance of short cationic antimicrobial peptide isomers.

    Science.gov (United States)

    Juba, Melanie; Porter, Devin; Dean, Scott; Gillmor, Susan; Bishop, Barney

    2013-07-01

    Cationic antimicrobial peptides (CAMPs) represent an ancient defense mechanism against invading bacteria, with peptides such as the cathelicidins being essential elements of vertebrate innate immunity. CAMPs are typically associated with broad-spectrum antimicrobial potency and limited bacterial resistance. The cathelicidin identified from the elapid snake Naja atra (NA-CATH) contains a semi-conserved repeated 11-residue motif (ATRA motif) with a sequence pattern consistent with formation of an amphipathic helical conformation. Short peptide amides (ATRA-1, -1A, -1P, and -2) generated based on the pair of ATRA motifs in NA-CATH exhibited varied antimicrobial potencies. The small size of the ATRA peptides, coupled with their varied antimicrobial performances, make them interesting models to study the impact various physico-chemical properties have on antimicrobial performance in helical CAMPs. Accordingly, the D- and L-enantiomers of the peptide ATRA-1A, which in earlier studies had shown both good antimicrobial performance and strong helical character, were investigated in order to assess the impact peptide stereochemistry has on antimicrobial performance and interaction with chiral membranes. The ATRA-1A isomers exhibit varied potencies against four bacterial strains, and their conformational properties in the presence of mixed zwitterionic/anionic liposomes are influenced by anionic lipid content. These studies reveal subtle differences in the properties of the peptide isomers. Differences are also seen in the abilities of the ATRA-1A isomers to induce liposome fusion/aggregation, bilayer rearrangement and lysing through turbidity studies and fluorescence microscopy. The similarities and differences in the properties of the ATRA-1A isomers could aid in efforts to develop D-peptide-based therapeutics using high-performing L-peptides as templates.

  20. Discrimination of eight chloramphenicol isomers by liquid chromatography tandem mass spectrometry in order to investigate the natural occurrence of chloramphenicol.

    Science.gov (United States)

    Berendsen, Bjorn J A; Zuidema, Tina; de Jong, Jacob; Stolker, Linda A A M; Nielen, Michel W F

    2011-08-26

    This paper describes the discrimination of eight different isomers of chloramphenicol (CAP), an antibiotic banned for use in food producing animals, by reversed phase and chiral liquid chromatography in combination with tandem mass spectrometric detection. Previously, by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) the presence of CAP was confirmed in some grass and herb samples collected on Mongolian pastures up to concentrations of 450 μg kg(-1). It was not possible to establish the cause of CAP residues which has initiated research on the natural occurrence of this drug. CAP occurs in the para-configuration and in the meta-configuration and contains two chiral centers thus eight different isomeric configurations exist, namely four (RR, SS, RS, SR) meta-stereoisomers and four para-stereoisomers. It is known that only RR-p-CAP has antimicrobial properties. To find out if the CAP detected in the plant material samples is the active configuration, a high resolution reversed phase LC-MS/MS system was tested for its ability to separate the different isomers. This system proved to be able to discriminate between some isomers, but not between RR-p-CAP and SS-p-CAP, also called dextramycin. Despite a detailed elucidation of the product ions and the fragmentation patterns of all isomers, MS/MS did not add sufficient specificity for full discrimination of the isomers. Therefore a chiral liquid chromatographic separation with MS/MS detection that is able to distinguish all isomers was developed and finally the isomeric ratio of non-compliant plant material samples and some CAP formulations was determined using this system. This showed that Mongolian grass and herb samples only contain the biological active isomer of CAP as do the obtained formulations. Therefore the CAP present in the plant material might origin from the production by soil organisms or from a manufactured source.

  1. Chiral Nanoscience and Nanotechnology

    Directory of Open Access Journals (Sweden)

    Dibyendu S. Bag

    2008-09-01

    Full Text Available The paper reviews nanoscale science and technology of chiral molecules/macromolecules-under twosubtopics-chiral nanotechnology and nano-chiral technology. Chiral nanotechnology discusses thenanotechnology, where molecular chirality plays a role in the properties of materials, including molecularswitches, molecular motors, and other molecular devices; chiral supramolecules and self-assembled nanotubesand their functions are also highlighted. Nano-chiral technology  describes the nanoscale approaches to chiraltechnology such as asymmetric synthesis and catalysis, chiral separation and detection, and enantiomericanalysis. Chiral sensors have also been included. The state-of-the-art chiral research at DMSRDE,Kanpur isalso presented.Defence Science Journal, 2008, 58(5, pp.626-635, DOI:http://dx.doi.org/10.14429/dsj.58.1685

  2. Astaxanthin: structural and functional aspects Astaxantina: aspectos estruturais e funcionais

    Directory of Open Access Journals (Sweden)

    Larissa Mont'Alverne Jucá Seabra

    2010-12-01

    Full Text Available Astaxanthin, a carotenoid belonging to the xanthophyll class, has stirred great interest due to its antioxidant capacity and its possible role in reducing the risk of some diseases. Astaxanthin occurs naturally in microalgae, such as Haematococcus pluvialis and the yeast Phaffia rhodozyma, and has also been considered to be the major carotenoid in salmon and crustaceans. Shrimp processing waste, which is generally discarded, is also an important source of astaxanthin. The antioxidant activity of astaxanthin has been observed to modulate biological functions related to lipid peroxidation, having beneficial effects on chronic diseases such as cardiovascular disease, macular degeneration and cancer. Researches have shown that both astaxanthin obtained from natural sources and its synthetic counterpart produce satisfactory effects, but studies in humans are limited to natural sources. There is no established nutritional recommendation regarding astaxanthin daily intake but most studies reported beneficial results from a daily intake of 4mg. Thus, this review discusses some aspects of the carotenoid astaxanthin, highlighting its chemical structure and antioxidant activity, and some studies that report its use in humans.A astaxantina, carotenóide pertencente à classe das xantofilas, tem despertado grande interesse devido à sua capacidade antioxidante e possível papel na redução de risco de algumas doenças. A astaxantina pode ser encontrada naturalmente em microalgas como Haematococcus pluvialis e na levedura Phaffia rhodozyma como também tem sido considerada principal carotenóide em salmão e crustáceos. Os resíduos do processamento de camarão, geralmente descartados, são também importante fonte de astaxantina. A atividade antioxidante da astaxantina tem demonstrado importante função na modulação de funções biológicas relacionadas à peroxidação lipídica, desempenhando efeitos benéficos em doenças crônicas como doen

  3. Chiral mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Plum, Eric, E-mail: erp@orc.soton.ac.uk [Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Zheludev, Nikolay I., E-mail: niz@orc.soton.ac.uk [Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); The Photonics Institute and Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637378 (Singapore)

    2015-06-01

    Mirrors are used in telescopes, microscopes, photo cameras, lasers, satellite dishes, and everywhere else, where redirection of electromagnetic radiation is required making them arguably the most important optical component. While conventional isotropic mirrors will reflect linear polarizations without change, the handedness of circularly polarized waves is reversed upon reflection. Here, we demonstrate a type of mirror reflecting one circular polarization without changing its handedness, while absorbing the other. The polarization-preserving mirror consists of a planar metasurface with a subwavelength pattern that cannot be superimposed with its mirror image without being lifted out of its plane, and a conventional mirror spaced by a fraction of the wavelength from the metasurface. Such mirrors enable circularly polarized lasers and Fabry-Pérot cavities with enhanced tunability, gyroscopic applications, polarization-sensitive detectors of electromagnetic waves, and can be used to enhance spectroscopies of chiral media.

  4. Isomers chart; Table des isomeres

    Energy Technology Data Exchange (ETDEWEB)

    Dupont-Gautier, P.; Chantelot, S.; Moisson, N. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    The nuclear isomers are nuclides offering the same mass number and the same atomic number, but different energy levels. In the following chart the zero energy ground states are omitted and the metastable isomers, i.e. of non-zero energy, known and of measurable lifetime, are listed. The lower limit of this lifetime was set here to 0.1 x 10{sup -6} s. The various isomers were classified in increasing lifetimes. (authors) [French] Les isomeres nucleaires sont des nucleides presentant le meme nombre de masse et le meme numero atomique, mais des niveaux energetiques differents. Dans la table suivante, on a neglige les etats fondamentaux d'energie nulle et on a recense les isomeres metastables, c'est-a-dire d'energie non nulle, connus et de periode mesurable. La limite inferieure de cette periode a ete fixee ici a 0,1 x 10{sup -6} s. Les differents isomeres ont ete classes par periodes croissantes. (auteurs)

  5. Astaxanthin from Haematococcus pluvialis Prevents Oxidative Stress on Human Endothelial Cells without Toxicity

    Science.gov (United States)

    Régnier, Philippe; Bastias, Jorge; Rodriguez-Ruiz, Violeta; Caballero-Casero, Noelia; Caballo, Carmen; Sicilia, Dolores; Fuentes, Axelle; Maire, Murielle; Crepin, Michel; Letourneur, Didier; Gueguen, Virginie; Rubio, Soledad; Pavon-Djavid, Graciela

    2015-01-01

    Astaxanthin, a powerful antioxidant, is a good candidate for the prevention of intracellular oxidative stress. The aim of the study was to compare the antioxidant activity of astaxanthin present in two natural extracts from Haematococcus pluvialis, a microalgae strain, with that of synthetic astaxanthin. Natural extracts were obtained either by solvent or supercritical extraction methods. UV, HPLC-DAD and (HPLC-(atmospheric pressure chemical ionization (APCI)+)/ion trap-MS) characterizations of both natural extracts showed similar compositions of carotenoids, but different percentages in free astaxanthin and its ester derivatives. The Trolox equivalent antioxidant capacity (TEAC) assay showed that natural extracts containing esters displayed stronger antioxidant activities than free astaxanthin. Their antioxidant capacities to inhibit intracellular oxidative stress were then evaluated on HUVEC cells. The intracellular antioxidant activity in natural extracts was approximately 90-times higher than synthetic astaxanthin (5 µM). No modification, neither in the morphology nor in the viability, of vascular human cells was observed by in vitro biocompatibility study up to 10 µM astaxanthin concentrations. Therefore, these results revealed the therapeutic potential of the natural extracts in vascular human cell protection against oxidative stress without toxicity, which could be exploited in prevention and/or treatment of cardiovascular diseases. PMID:25962124

  6. Assessment and comparison of in vitro immunoregulatory activity of three astaxanthin stereoisomers

    Science.gov (United States)

    Sun, Weihong; Xing, Lihong; Lin, Hong; Leng, Kailiang; Zhai, Yuxiu; Liu, Xiaofang

    2016-04-01

    In recent years, the immune-modulatory role of all- trans astaxanthin from different pigment sources has been studied. It was reported that all- trans astaxanthin might exist as three stereoisomers, and the composition of all- trans stereoisomers in natural materials differs from that of synthetic products. However, the different biological effects of various all- trans stereoisomers still remain unclear. In the present study, we evaluated the bioactivity of three astaxanthin stereoisomers, ( 3S, 3'S)- trans-, ( 3R,3'R)- trans-and meso-trans-astaxanthin, in regulating cell-mediated immune response using mice lymphocytes and peritoneal exudates cells (PECs) systems. After the treatment with three astaxanthin stereoisomers (20 μmol L-1), the lymphocyte proliferation capacity, neutral red phagocytosis of PECs and natural killer (NK) cell cytotoxic activity were comparatively assessed. The results showed that all three astaxanthin stereoisomers significantly promoted lymphocyte proliferation, phagocytic capacity of PECs, and cytotoxic activity of NK cells. Moreover, the ( 3S,3'S)-trans-astaxanthin exhibited a much higher response than others.

  7. Preventive effect of dietary astaxanthin on UVA-induced skin photoaging in hairless mice

    Science.gov (United States)

    Komatsu, Toshiyuki; Sasaki, Suguru; Manabe, Yuki; Hirata, Takashi

    2017-01-01

    Astaxanthin, a carotenoid found mainly in seafood, has potential clinical applications due to its antioxidant activity. In this study, we evaluated the effect of dietary astaxanthin derived from Haematococcus pluvialis on skin photoaging in UVA-irradiated hairless mice by assessing various parameters of photoaging. After chronic ultraviolet A (UVA) exposure, a significant increase in transepidermal water loss (TEWL) and wrinkle formation in the dorsal skin caused by UVA was observed, and dietary astaxanthin significantly suppressed these photoaging features. We found that the mRNA expression of lympho-epithelial Kazal-type-related inhibitor, steroid sulfatase, and aquaporin 3 in the epidermis was significantly increased by UVA irradiation for 70 days, and dietary astaxanthin significantly suppressed these increases in mRNA expression to be comparable to control levels. In the dermis, the mRNA expression of matrix metalloprotease 13 was increased by UVA irradiation and significantly suppressed by dietary astaxanthin. In addition, HPLC-PDA analysis confirmed that dietary astaxanthin reached not only the dermis but also the epidermis. Our results indicate that dietary astaxanthin accumulates in the skin and appears to prevent the effects of UVA irradiation on filaggrin metabolism and desquamation in the epidermis and the extracellular matrix in the dermis. PMID:28170435

  8. Astaxanthin from Haematococcus pluvialis Prevents Oxidative Stress on Human Endothelial Cells without Toxicity

    Directory of Open Access Journals (Sweden)

    Philippe Régnier

    2015-05-01

    Full Text Available Astaxanthin, a powerful antioxidant, is a good candidate for the prevention of intracellular oxidative stress. The aim of the study was to compare the antioxidant activity of astaxanthin present in two natural extracts from Haematococcus pluvialis, a microalgae strain, with that of synthetic astaxanthin. Natural extracts were obtained either by solvent or supercritical extraction methods. UV, HPLC-DAD and (HPLC-(atmospheric pressure chemical ionization (APCI+/ion trap-MS characterizations of both natural extracts showed similar compositions of carotenoids, but different percentages in free astaxanthin and its ester derivatives. The Trolox equivalent antioxidant capacity (TEAC assay showed that natural extracts containing esters displayed stronger antioxidant activities than free astaxanthin. Their antioxidant capacities to inhibit intracellular oxidative stress were then evaluated on HUVEC cells. The intracellular antioxidant activity in natural extracts was approximately 90-times higher than synthetic astaxanthin (5 µM. No modification, neither in the morphology nor in the viability, of vascular human cells was observed by in vitro biocompatibility study up to 10 µM astaxanthin concentrations. Therefore, these results revealed the therapeutic potential of the natural extracts in vascular human cell protection against oxidative stress without toxicity, which could be exploited in prevention and/or treatment of cardiovascular diseases.

  9. Astaxanthin from Haematococcus pluvialis Prevents Oxidative Stress on Human Endothelial Cells without Toxicity.

    Science.gov (United States)

    Régnier, Philippe; Bastias, Jorge; Rodriguez-Ruiz, Violeta; Caballero-Casero, Noelia; Caballo, Carmen; Sicilia, Dolores; Fuentes, Axelle; Maire, Murielle; Crepin, Michel; Letourneur, Didier; Gueguen, Virginie; Rubio, Soledad; Pavon-Djavid, Graciela

    2015-05-07

    Astaxanthin, a powerful antioxidant, is a good candidate for the prevention of intracellular oxidative stress. The aim of the study was to compare the antioxidant activity of astaxanthin present in two natural extracts from Haematococcus pluvialis, a microalgae strain, with that of synthetic astaxanthin. Natural extracts were obtained either by solvent or supercritical extraction methods. UV, HPLC-DAD and (HPLC-(atmospheric pressure chemical ionization (APCI)+)/ion trap-MS) characterizations of both natural extracts showed similar compositions of carotenoids, but different percentages in free astaxanthin and its ester derivatives. The Trolox equivalent antioxidant capacity (TEAC) assay showed that natural extracts containing esters displayed stronger antioxidant activities than free astaxanthin. Their antioxidant capacities to inhibit intracellular oxidative stress were then evaluated on HUVEC cells. The intracellular antioxidant activity in natural extracts was approximately 90-times higher than synthetic astaxanthin (5 µM). No modification, neither in the morphology nor in the viability, of vascular human cells was observed by in vitro biocompatibility study up to 10 µM astaxanthin concentrations. Therefore, these results revealed the therapeutic potential of the natural extracts in vascular human cell protection against oxidative stress without toxicity, which could be exploited in prevention and/or treatment of cardiovascular diseases.

  10. Chlorella zofingiensis as an alternative microalgal producer of astaxanthin: biology and industrial potential.

    Science.gov (United States)

    Liu, Jin; Sun, Zheng; Gerken, Henri; Liu, Zheng; Jiang, Yue; Chen, Feng

    2014-06-10

    Astaxanthin (3,3'-dihydroxy-β,β-carotene-4,4'-dione), a high-value ketocarotenoid with a broad range of applications in food, feed, nutraceutical, and pharmaceutical industries, has been gaining great attention from science and the public in recent years. The green microalgae Haematococcus pluvialis and Chlorella zofingiensis represent the most promising producers of natural astaxanthin. Although H. pluvialis possesses the highest intracellular astaxanthin content and is now believed to be a good producer of astaxanthin, it has intrinsic shortcomings such as slow growth rate, low biomass yield, and a high light requirement. In contrast, C. zofingiensis grows fast phototrophically, heterotrophically and mixtrophically, is easy to be cultured and scaled up both indoors and outdoors, and can achieve ultrahigh cell densities. These robust biotechnological traits provide C. zofingiensis with high potential to be a better organism than H. pluvialis for mass astaxanthin production. This review aims to provide an overview of the biology and industrial potential of C. zofingiensis as an alternative astaxanthin producer. The path forward for further expansion of the astaxanthin production from C. zofingiensis with respect to both challenges and opportunities is also discussed.

  11. Astaxanthin prevents pulmonary fibrosis by promoting myofibroblast apoptosis dependent on Drp1-mediated mitochondrial fission.

    Science.gov (United States)

    Zhang, Jinjin; Xu, Pan; Wang, Youlei; Wang, Meirong; Li, Hongbo; Lin, Shengcui; Mao, Cuiping; Wang, Bingsi; Song, Xiaodong; Lv, Changjun

    2015-09-01

    Promotion of myofibroblast apoptosis is a potential therapeutic strategy for pulmonary fibrosis. This study investigated the antifibrotic effect of astaxanthin on the promotion of myofibroblast apoptosis based on dynamin-related protein-1 (Drp1)-mediated mitochondrial fission in vivo and in vitro. Results showed that astaxanthin can inhibit lung parenchymal distortion and collagen deposition, as well as promote myofibroblast apoptosis. Astaxanthin demonstrated pro-apoptotic function in myofibroblasts by contributing to mitochondrial fission, thereby leading to apoptosis by increasing the Drp1 expression and enhancing Drp1 translocation into the mitochondria. Two specific siRNAs were used to demonstrate that Drp1 is necessary to promote astaxanthin-induced mitochondrial fission and apoptosis in myofibroblasts. Drp1-associated genes, such as Bcl-2-associated X protein, cytochrome c, tumour suppressor gene p53 and p53-up-regulated modulator of apoptosis, were highly up-regulated in the astaxanthin group compared with those in the sham group. This study revealed that astaxanthin can prevent pulmonary fibrosis by promoting myofibroblast apoptosis through a Drp1-dependent molecular pathway. Furthermore, astaxanthin provides a potential therapeutic value in pulmonary fibrosis treatment.

  12. The protective effect of astaxanthin on fetal alcohol spectrum disorder in mice.

    Science.gov (United States)

    Zheng, Dong; Li, Yi; He, Lei; Tang, Yamei; Li, Xiangpen; Shen, Qingyu; Yin, Deling; Peng, Ying

    2014-09-01

    Astaxanthin is a strong antioxidant with the ability of reducing the markers of inflammation. To explore the protective effect of astaxanthin on maternal ethanol induced embryonic deficiency, and to investigate the underlying mechanisms, we detected the morphology, expression of neural marker genes, oxidative stress indexes, and inflammatory factors in mice model of fetal alcohol spectrum disorder with or without astaxanthin pretreatment. Our results showed that astaxanthin blocked maternal ethanol induced retardation of embryonic growth, and the down-regulation of neural marker genes, Otx1 and Sox2. Moreover, astaxanthin also reversed the increases of malondialdehyde (MDA), hydrogen peroxide (H2O2), and the decrease of glutathione peroxidase (GPx) in fetal alcohol spectrum disorder. In addition, maternal ethanol induced up-regulation of toll-like receptor 4 (TLR4), and the down-streaming myeloid differentiation factor 88 (MyD88), NF-κB, TNF-α, and IL-1β in embryos, and this was inhibited by astaxanthin pretreatment. These results demonstrated a protective effect of astaxanthin on fetal alcohol spectrum disorder, and suggested that oxidative stress and TLR4 signaling associated inflammatory reaction are involved in this process.

  13. Inhibition of inflammation by astaxanthin alleviates cognition deficits in diabetic mice.

    Science.gov (United States)

    Zhou, Xiaoyan; Zhang, Fang; Hu, Xiaotong; Chen, Jing; Wen, Xiangru; Sun, Ying; Liu, Yonghai; Tang, Renxian; Zheng, Kuiyang; Song, Yuanjian

    2015-11-01

    Neurons in the hippocampal and cortical functional regions are more susceptible to damage induced by hyperglycemia, which can result in severe spatial learning and memory impairment. Neuroprotection ameliorates cognitive impairment induced by hyperglycemia in diabetic encephalopathy (DE). Astaxanthin has been widely studied in diabetes mellitus and diabetic complications due to its hypoglycemic, antioxidant and anti-apoptotic effects. However, whether astaxanthin can alleviate cognition deficits induced by DE and its precise mechanisms remain undetermined. In this study, DE was induced by streptozotocin (STZ, 150 mg/kg) in ICR mice. We observed the effect of astaxanthin on cognition and investigated its potential mechanisms in DE mice. Results showed that astaxanthin treatment significantly decreased the latency and enhanced the distance and time spent in the target quadrant in the Morris water maze test. Furthermore, neuronal survival was significantly increased in the hippocampal CA3 region and the frontal cortex following treatment with astaxanthin. Meanwhile, immunoblotting was used to observe the nuclear translocation of nuclear factor-kappaB (NF-κB) p65 and the expression of tumor necrosis factor-α (TNF-α) in the hippocampus and frontal cortex. The results indicated that astaxanthin could inhibit NF-κB nuclear translocation and downregulate TNF-α expression in the hippocampus and frontal cortex. Overall, the present study implied that astaxanthin could improve cognition by protecting neurons against inflammation injury potentially through inhibiting the nuclear translocation of NF-κB and down-regulating TNF-α.

  14. Astaxanthin reduces isoflurane-induced neuroapoptosis via the PI3K/Akt pathway.

    Science.gov (United States)

    Wang, Chun-Mei; Cai, Xiao-Lan; Wen, Qing-Ping

    2016-05-01

    Astaxanthin is an oxygen-containing derivative of carotenoids that effectively suppresses reactive oxygen and has nutritional and medicinal value. The mechanisms underlying the effects of astaxanthin on isoflurane‑induced neuroapoptosis remain to be fully understood. The present study was conducted to evaluate the protective effect of astaxanthin to reduce isoflurane‑induced neuroapoptosis and to investigate the underlying mechanisms. The results demonstrated that isoflurane induced brain damage, increased caspase‑3 activity and suppressed the phosphatidylinositol 3‑kinase (PI3K)/protein kinase B (Akt) signaling pathway in an in vivo model. However, treatment with astaxanthin significantly inhibited brain damage, suppressed caspase‑3 activity and upregulated the PI3K/Akt pathway in the isoflurane‑induced rats. Furthermore, isoflurane suppressed cell growth, induced cell apoptosis, enhanced caspase‑3 activity and downregulated the PI3K/Akt pathway in organotypic hippocampal slice culture. Administration of astaxanthin significantly promoted cell growth, reduced cell apoptosis and caspase‑3 activity, and upregulated the PI3K/Akt pathway and isoflurane‑induced neuroapoptosis. The present study demonstrated that downregulation of the PI3K/Akt pathway reduced the effect of astaxanthin to protect against isoflurane‑induced neuroapoptosis in the in vitro model. The results of the current study suggested that the protective effect of astaxanthin reduces the isoflurane-induced neuroapoptosis via activation of the PI3K/Akt signaling pathway.

  15. Subchronic (13-week) toxicity and prenatal developmental toxicity studies of dietary astaxanthin in rats.

    Science.gov (United States)

    Vega, Katherine; Edwards, James; Beilstein, Paul

    2015-12-01

    Two studies examined the effects of dietary astaxanthin on Hanlbm Wistar (SPF) rats. Male and female rats receiving astaxanthin concentrations up to 1.52% of the feed for 13 weeks showed no evidence of toxicity; no effects were noted in the offspring of female rats exposed to astaxanthin at up to 1.39% of the feed during the period of organogenesis (GD 7-16). Discoloration of the feces and yellow pigmentation of adipose tissue was seen in the 13-week study, an intrinsic property of the substance, and not a sign of toxicity. Differences between the control and astaxanthin groups, some of which reached statistical significance, were generally sporadic (i.e., transient and/or not related to astaxanthin concentration) and not considered of biological or toxicological significance. Blood cholesterol levels, for example, were greater in animals receiving astaxanthin for 13 weeks, but remained within the normal range. The highest dietary concentration of astaxanthin in each of the studies is proposed as a no-observable-adverse-effect level (NOAEL). Specifically, 1.52% for the 13-week study, corresponding to a mean intake of 1033 mg/kg bw/day (range: 880-1240 mg/kg bw/day), and 1.39% for the developmental toxicity study, corresponding to a mean intake of approximately 830 mg/kg bw/day (range: 457-957 mg/kg bw/day).

  16. EXTRACTION OF ASTAXANTHIN ESTERS FROM SHRIMP WASTE BY CHEMICAL AND MICROBIAL METHODS

    Directory of Open Access Journals (Sweden)

    A. Khanafari, A. Saberi, M. Azar, Gh. Vosooghi, Sh. Jamili, B. Sabbaghzadeh

    2007-04-01

    Full Text Available The carotenoid pigments specifically astaxanthin has many significant applications in food, pharmaceutical and cosmetic industries. The goal of this research was the extraction of Astaxanthin from a certain Persian Gulf shrimp species waste (Penaeus semisulcatus, purification and identification of the pigment by chemical and microbial methods. Microbial fermentation was obtained by inoculation of two Lactobacillus species Lb. plantarum and Lb. acidophilus in the medium culture containing shrimp waste powder by the intervention of lactose sugar, yeast extract, the composition of Both and the coolage (-20oC. The carotenoids were extracted by an organic solvent system. After purification of astaxanthin with the thin layer chromatography method by spectrophotometer, NMR and IR analysis the presence of astaxanthin esters was recognized in this specific species of Persian Gulf shrimp. Results obtained from this study showed that the coolage at –20 oC not only does not have an amplifying effect on the production of astaxanthin but also slightly reduces this effect. Also the effect of intervention of lactose sugar showed more effectiveness in producing astaxanthin than yeast extract or more than with the presence of both. The results also indicated that there is not much difference in the ability of producing the pigment by comparing both Lb. plantarum and Lb. acidophillus. Also results showed the microbial method of extraction of astaxanthin is more effective than chemical method. The pigment extracted from certain amount of shrimp powder, 23.128 mg/g, was calculated.

  17. Astaxanthin ameliorates aluminum chloride-induced spatial memory impairment and neuronal oxidative stress in mice.

    Science.gov (United States)

    Al-Amin, Md Mamun; Reza, Hasan Mahmud; Saadi, Hasan Mahmud; Mahmud, Waich; Ibrahim, Abdirahman Adam; Alam, Musrura Mefta; Kabir, Nadia; Saifullah, A R M; Tropa, Sarjana Tarannum; Quddus, A H M Ruhul

    2016-04-15

    Aluminum chloride induces neurodegenerative disease in animal model. Evidence suggests that aluminum intake results in the activation of glial cells and generation of reactive oxygen species. By contrast, astaxanthin is an antioxidant having potential neuroprotective activity. In this study, we investigate the effect of astaxanthin on aluminum chloride-exposed behavioral brain function and neuronal oxidative stress (OS). Male Swiss albino mice (4 months old) were divided into 4 groups: (i) control (distilled water), (ii) aluminum chloride, (iii) astaxanthin+aluminum chloride, and (iv) astaxanthin. Two behavioral tests; radial arm maze and open field test were conducted, and OS markers were assayed from the brain and liver tissues following 42 days of treatment. Aluminum exposed group showed a significant reduction in spatial memory performance and anxiety-like behavior. Moreover, aluminum group exhibited a marked deterioration of oxidative markers; lipid peroxidation (MDA), nitric oxide (NO), glutathione (GSH) and advanced oxidation of protein products (AOPP) in the brain. To the contrary, co-administration of astaxanthin and aluminum has shown improved spatial memory, locomotor activity, and OS. These results indicate that astaxanthin improves aluminum-induced impaired memory performances presumably by the reduction of OS in the distinct brain regions. We suggest a future study to determine the underlying mechanism of astaxanthin in improving aluminum-exposed behavioral deficits.

  18. Studies on the metabolism of astaxanthin in the rainbow trout (Salmo gairdneri)

    Energy Technology Data Exchange (ETDEWEB)

    Al-Khalifah, A.S.

    1986-01-01

    Racemic astaxanthin was fed to rainbow trout (Salmo gairdneri) for 2, 4, and 6 weeks. The fish showed a bright pink coloration of the skin and flesh; the highest amount of astaxanthin was found in the skin of fish fed the test diet for six weeks. Lutein, 3-epilutein, and zeaxanthin were also detected in the flesh and skin; it was concluded that astaxanthin was converted to zeaxanthin in the skin. The mean vitamin A content of the liver was determined; the ratio of vitamin A/sub 1/:vitamin A/sub 2/ was approximately 1:3. Retinol and 3,4-dehydroretinol were extracted from the intestine of rainbow trout low in vitamin A, after force feeding with astaxanthin using a feeding tube. Antibiotic-treated fish had no marked difference in vitamin A content compared with a control group that received no antibiotic. This proves that astaxanthin was converted to vitamin A in fish depleted of vitamin A, that microorganisms were not involved in the conversion, and that conversion occurred in the intestine. An in vitro study using /sup 3/H 3S, 3S'-astaxanthin incubated with duodenal and ileal segments of the intestine provided HLPC and radioisotope data, which showed that rainbow trout were able to bioconvert astaxanthin to vitamin A.

  19. Recent breakthroughs in the biology of astaxanthin accumulation by microalgal cell.

    Science.gov (United States)

    Solovchenko, Alexei E

    2015-09-01

    Massive accumulation of the secondary ketokarotenoid astaxanthin is a characteristic stress response of certain microalgal species with Haematococcus pluvialis as an illustrious example. The carotenogenic response confers these organisms a remarkable ability to survive in extremely unfavorable environments and makes them the richest source of natural astaxanthin. Exerting a plethora of beneficial effects on human and animal health, astaxanthin is among the most important bioproducts from microalgae. Though our understanding of astaxanthin biosynthesis, induction, and regulation is far from complete, this gap is filling rapidly with new knowledge generated predominantly by application of advanced "omics" approaches. This review focuses on the most recent progress in the biology of astaxanthin accumulation in microalgae including the genomic, proteomic, and metabolomics insights into the induction and regulation of secondary carotenogenesis and its role in stress tolerance of the photosynthetic microorganisms. Special attention is paid to the coupling of the carotenoid and lipid biosynthesis as well as deposition of astaxanthin in the algal cell. The place of the carotenogenic response among the stress tolerance mechanisms is revisited, and possible implications of the new findings for biotechnological production of astaxanthin from microalgae are considered. The potential use of the carotenogenic microalgae as a source not only of value-added carotenoids, but also of biofuel precursors is discussed.

  20. Ethanol induced astaxanthin accumulation and transcriptional expression of carotenogenic genes in Haematococcus pluvialis.

    Science.gov (United States)

    Wen, Zewen; Liu, Zhiyong; Hou, Yuyong; Liu, Chenfeng; Gao, Feng; Zheng, Yubin; Chen, Fangjian

    2015-10-01

    Haematococcus pluvialis is one of the most promising natural sources of astaxanthin. However, inducing the accumulation process has become one of the primary obstacles in astaxanthin production. In this study, the effect of ethanol on astaxanthin accumulation was investigated. The results demonstrated that astaxanthin accumulation occurred with ethanol addition even under low-light conditions. The astaxanthin productivity could reach 11.26 mg L(-1) d(-1) at 3% (v/v) ethanol, which was 2.03 times of that of the control. The transcriptional expression patterns of eight carotenogenic genes were evaluated using real-time PCR. The results showed that ethanol greatly enhanced transcription of the isopentenyl diphosphate (IPP) isomerase genes (ipi-1 and ipi-2), which were responsible for isomerization reaction of IPP and dimethylallyl diphosphate (DMAPP). This finding suggests that ethanol induced astaxanthin biosynthesis was up-regulated mainly by ipi-1 and ipi-2 at transcriptional level, promoting isoprenoid synthesis and substrate supply to carotenoid formation. Thus ethanol has the potential to be used as an effective reagent to induce astaxanthin accumulation in H. pluvialis.

  1. Chlorella zofingiensis as an Alternative Microalgal Producer of Astaxanthin: Biology and Industrial Potential

    Directory of Open Access Journals (Sweden)

    Jin Liu

    2014-06-01

    Full Text Available Astaxanthin (3,3′-dihydroxy-β,β-carotene-4,4′-dione, a high-value ketocarotenoid with a broad range of applications in food, feed, nutraceutical, and pharmaceutical industries, has been gaining great attention from science and the public in recent years. The green microalgae Haematococcus pluvialis and Chlorella zofingiensis represent the most promising producers of natural astaxanthin. Although H. pluvialis possesses the highest intracellular astaxanthin content and is now believed to be a good producer of astaxanthin, it has intrinsic shortcomings such as slow growth rate, low biomass yield, and a high light requirement. In contrast, C. zofingiensis grows fast phototrophically, heterotrophically and mixtrophically, is easy to be cultured and scaled up both indoors and outdoors, and can achieve ultrahigh cell densities. These robust biotechnological traits provide C. zofingiensis with high potential to be a better organism than H. pluvialis for mass astaxanthin production. This review aims to provide an overview of the biology and industrial potential of C. zofingiensis as an alternative astaxanthin producer. The path forward for further expansion of the astaxanthin production from C. zofingiensis with respect to both challenges and opportunities is also discussed.

  2. High-titer production of astaxanthin by the semi-industrial fermentation of Xanthophyllomyces dendrorhous.

    Science.gov (United States)

    de la Fuente, Juan Luis; Rodríguez-Sáiz, Marta; Schleissner, Carmen; Díez, Bruno; Peiro, Enrique; Barredo, José Luis

    2010-07-20

    An improved semi-industrial process for astaxanthin production by fermentation of Xanthophyllomyces dendrorhous has been developed. The culture medium was designed at the flask scale, reaching an astaxanthin cellular content of 3.0 mgg(-1) cell weight and a volumetric yield of 119 mgL(-1) broth. Astaxanthin production in flask was significantly improved by white light (4.0 mgg(-1) and 221 mgL(-1)), and by ultraviolet light (4.4 mgg(-1) and 235 mgL(-1)). The scale-up to 10- and 800-L fermentors was developed by feeding with glucose. Representative data for illuminated fermentation processes are presented and discussed at the 10-L scale, where 420 mgL(-1) (4.7 mgg(-1)) astaxanthin were produced, and the 800-L scale, with productivities of 350 mgL(-1) (4.1 mgg(-1)) astaxanthin. The purity of the astaxanthin in the broth was about 84%, with accumulation of the following carotenoids other than astaxanthin: 4% beta-carotene, 4% canthaxanthin, 5% HDCO, 1% zeaxanthin and 2% phoenicoxanthin. This technology can be easily scaled-up to an industrial application for the production of this xanthophyll widely demanded nowadays.

  3. Use of achiral/chiral SFC/MS for the profiling of isomeric cinnamonitrile/hydrocinnamonitrile products in chiral drug synthesis.

    Science.gov (United States)

    Alexander, A J; Staab, A

    2006-06-01

    A directly coupled achiral/chiral SFC/MS method has been developed for the profiling of a three-step stereoselective synthesis of cinnamonitrile and hydrocinnamonitrile intermediates. Semipurified reaction mixtures were screened in one step to determine the diastereomeric/enantiomeric composition of the final product as well as to identify any remaining E/Z isomers present from the starting material. The coupled achiral/chiral column combination was found to significantly enhance the separation of both enantiomers and diastereomers, without adding significantly to the overall analysis time. This analytical technique should prove to be generally useful for the profiling of isomeric reaction products in chiral drug synthesis.

  4. Molecular chirality at surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, Karl-Heinz [Empa, Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, 8600 Duebendorf (Switzerland); Organic Chemistry Institute, University Zurich, 8057 Zuerich (Switzerland)

    2012-11-15

    With the adsorption of larger molecules being increasingly tackled by surface scientists, the aspect of chirality often plays a role. This paper gives a topical review of molecular chirality at surfaces and gives a phenomenological overview of different aspects of adsorption and self-assembly of chiral and prochiral molecules and the principles of mirror-symmetry breaking at a surface. After a brief introduction into the history of molecular chirality and the important role it played for understanding the spatial structure of molecules, definitions of chirality are presented. Topics treated here are principle ways to create single chiral adsorbates, chiral ensembles, and monolayers by achiral molecules, adsorption of intrinsically chiral molecules at achiral and chiral surfaces, long-range symmetry breaking in two-dimensional (2D) crystals due to additional chiral bias, chiral restructuring of solid surfaces under the influence of chiral molecules, switching the handedness of adsorbates, and chirality at the liquid/air interface. An outlook onto further potential research directions and recommendations for further reading, including nonsurface-related sources of chiral topics completes this paper. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Astaxanthin-Producing Green Microalga Haematococcus pluvialis: From Single Cell to High Value Commercial Products.

    Science.gov (United States)

    Shah, Md Mahfuzur R; Liang, Yuanmei; Cheng, Jay J; Daroch, Maurycy

    2016-01-01

    Many species of microalgae have been used as source of nutrient rich food, feed, and health promoting compounds. Among the commercially important microalgae, Haematococcus pluvialis is the richest source of natural astaxanthin which is considered as "super anti-oxidant." Natural astaxanthin produced by H. pluvialis has significantly greater antioxidant capacity than the synthetic one. Astaxanthin has important applications in the nutraceuticals, cosmetics, food, and aquaculture industries. It is now evident that, astaxanthin can significantly reduce free radicals and oxidative stress and help human body maintain a healthy state. With extraordinary potency and increase in demand, astaxanthin is one of the high-value microalgal products of the future.This comprehensive review summarizes the most important aspects of the biology, biochemical composition, biosynthesis, and astaxanthin accumulation in the cells of H. pluvialis and its wide range of applications for humans and animals. In this paper, important and recent developments ranging from cultivation, harvest and postharvest bio-processing technologies to metabolic control and genetic engineering are reviewed in detail, focusing on biomass and astaxanthin production from this biotechnologically important microalga. Simultaneously, critical bottlenecks and major challenges in commercial scale production; current and prospective global market of H. pluvialis derived astaxanthin are also presented in a critical manner. A new biorefinery concept for H. pluvialis has been also suggested to guide toward economically sustainable approach for microalgae cultivation and processing. This report could serve as a useful guide to present current status of knowledge in the field and highlight key areas for future development of H. pluvialis astaxanthin technology and its large scale commercial implementation.

  6. Astaxanthin-producing green microalga Haematococcus pluvialis: from single cell to high value commercial products

    Directory of Open Access Journals (Sweden)

    Md. Mahfuzur Rahman Shah

    2016-04-01

    Full Text Available Many species of microalgae have been used as source of nutrient rich food, feed and health promoting compounds. Among the commercially important microalgae, Haematococcus pluvialis is the richest source of natural astaxanthin which is considered as super anti-oxidant. Natural astaxanthin produced by H. pluvialis has significantly greater antioxidant capacity than the synthetic one. Astaxanthin has important applications in the nutraceuticals, cosmetics, food, and aquaculture industries. Thanks to many researches it is now evident, that astaxanthin can significantly reduce free radicals and oxidative stress and help human body maintain a healthy state. With extraordinary potency and increase in demand, astaxanthin is one of the high-value microalgal products of the future. Thus, this comprehensive review summarizes the most important aspects of the biology, biochemical composition, biosynthesis and astaxanthin accumulation in the cells of H. pluvialis and its wide range of applications for humans and animals. In this paper, important and recent developments ranging from cultivation, harvest and postharvest bio-processing technologies to metabolic control and genetic engineering are reviewed in detail, focusing on biomass and astaxanthin production from this biotechnologically important microalga. Simultaneously, critical bottlenecks and major challenges in commercial scale production; current and prospective global market of H. pluvialis derived astaxanthin are also presented in a critical manner. A new biorefinery concept for H. pluvialis has been also suggested to guide towards economically sustainable approach for microalgae cultivation and processing. This report could serve as a useful guide to present current status of knowledge in the field and highlight key areas for future development of H. pluvialis astaxanthin technology and its large scale commercial implementation.

  7. Impact of divergent effects of astaxanthin on insulin signaling in L6 cells.

    Science.gov (United States)

    Ishiki, Manabu; Nishida, Yasuhiro; Ishibashi, Hiroshi; Wada, Tsutomu; Fujisaka, Shiho; Takikawa, Akiko; Urakaze, Masaharu; Sasaoka, Toshiyasu; Usui, Isao; Tobe, Kazuyuki

    2013-08-01

    Because oxidative stress promotes insulin resistance in obesity and type 2 diabetes, it is crucial to find effective antioxidant for the purpose of decreasing this threat. In this study, we explored the effect of astaxanthin, a carotenoid antioxidant, on insulin signaling and investigated whether astaxanthin improves cytokine- and free fatty acid-induced insulin resistance in vitro. We examined the effect of astaxanthin on insulin-stimulated glucose transporter 4 (GLUT4) translocation, glucose uptake, and insulin signaling in cultured rat L6 muscle cells using plasma membrane lawn assay, 2-deoxyglucose uptake, and Western blot analysis. Next, we examined the effect of astaxanthin on TNFα- and palmitate-induced insulin resistance. The amount of reactive oxygen species generated by TNFα or palmitate with or without astaxanthin was evaluated by dichlorofluorescein staining. We also compared the effect of astaxanthin on insulin signaling with that of other antioxidants, α-lipoic acid and α-tocopherol. We observed astaxanthin enhanced insulin-stimulated GLUT4 translocation and glucose uptake, which was associated with an increase in insulin receptor substrate-1 tyrosine and Akt phosphorylation and a decrease in c-Jun N-terminal kinase (JNK) and insulin receptor substrate-1 serine 307 phosphorylation. Furthermore, astaxanthin restored TNFα- and palmitate-induced decreases in insulin-stimulated GLUT4 translocation or glucose uptake with a concomitant decrease in reactive oxygen species generation. α-Lipoic acid enhanced Akt phosphorylation and decreased ERK and JNK phosphorylation, whereas α-tocopherol enhanced ERK and JNK phosphorylation but had little effect on Akt phosphorylation. Collectively these findings indicate astaxanthin is a very effective antioxidant for ameliorating insulin resistance by protecting cells from oxidative stress generated by various stimuli including TNFα and palmitate.

  8. Astaxanthin production in marine pelagic copepods grazing on two different phytoplankton diets

    Science.gov (United States)

    Van Nieuwerburgh, Lies; Wänstrand, Ingrid; Liu, Jianguo; Snoeijs, Pauli

    2005-02-01

    The red carotenoid astaxanthin is a powerful natural antioxidant of great importance in aquatic food webs where it is abundant in eggs and body tissues of fish and crustaceans. Little is known about the impact of the phytoplankton diet on astaxanthin production in copepods, its major pelagic producers. We followed the transfer of carotenoids from phytoplankton to copepods in a mesocosm experiment on the northern Atlantic coast (Norway) and recorded the astaxanthin production in copepods. Wild copepods grazed on nutrient-manipulated phytoplankton blooms, which differed in community composition and nutrient status (nitrogen or silicate limitation). The copepod pigments consisted mainly of free astaxanthin and mono- and diesters of astaxanthin. We found no significant difference in astaxanthin production per copepod individual or per unit C depending on the phytoplankton community. However, in the mesocosms astaxanthin per unit C decreased compared with natural levels, probably through a lower demand for photoprotection by the copepods in the dense phytoplankton blooms. The total astaxanthin production per litre was higher in the silicate-limited mesocosms through increased copepod density. Pigment ratio comparisons suggested that the copepod diet here consisted more of diatoms than in the nitrogen-limited mesocosms. Silicate-saturated diatoms were less grazed, possibly because they could invest more in defence mechanisms against their predators. Our study suggests that the production of astaxanthin in aquatic systems can be affected by changes in nutrient dynamics mediated by phytoplankton community composition and copepod population growth. This bottom-up force may have implications for antioxidant protection at higher trophic levels in the food web.

  9. Perfusion culture process plus H2O2 stimulation for efficient astaxanthin production by Xanthophyllomyces dendrorhous.

    Science.gov (United States)

    Liu, Yuan Shuai; Wu, Jian Yong

    2007-06-15

    A semicontinuous perfusion culture process (repeated medium renewal with cell retention) was evaluated together with batch and repeated fed-batch processes for astaxanthin production in shake-flask cultures of Xanthophyllomyces dendrorhous. The perfusion process with 25% medium renewal every 12 h for 10 days achieved a biomass density of 65.6 g/L, a volumetric astaxanthin yield of 52.5 mg/L, and an astaxanthin productivity of 4.38 mg/L-d, which were 8.4-fold, 5.6-fold, and 2.3-fold of those in the batch process, 7.8 g/L, 9.4 mg/L, and 1.88 mg/L-d, respectively. The incorporation of hydrogen peroxide (H(2)O(2)) stimulation of astaxanthin biosynthesis into the perfusion process further increased the astaxanthin yield to 58.3 mg/L and the productivity to 4.86 mg/L-d. The repeated fed-batch process with 8 g/L glucose and 4 g/L corn steep liquor fed every 12 h achieved 42.2 g/L biomass density, 36.5 mg/L astaxanthin yield, and 3.04 mg/L-d astaxanthin productivity. The lower biomass and astaxanthin productivity in the repeated fed-batch than in the perfusion process may be mostly attributed to the accumulation of inhibitory metabolites such as ethanol and acetic acid in the culture. The study shows that perfusion process plus H(2)O(2) stimulation is an effective strategy for enhanced astaxanthin production in X. dendrorhous cultures.

  10. Effect of diets supplemented with different sources of astaxanthin on the gonad of the sea urchin Anthocidaris crassispina.

    Science.gov (United States)

    Peng, Juan; Yuan, Jian-Ping; Wang, Jiang-Hai

    2012-08-01

    The effect of the microalgae Haematococcus pluvialis and Chorella zofingiensis, and synthetic astaxanthin on the gonad of the sea urchin Anthocidaris crassispina was studied. The basal diet was supplemented with H. pluvialis, C. zofingiensis, or synthetic astaxanthin, at two levels of astaxanthin (approximately 400 mg/kg and 100 mg/kg), to obtain the experimental diets HP1, HP2, CZ1, CZ2, AST1, and AST2, respectively, for two months of feeding experiment. The results showed that the concentrations of astaxanthin in the gonads of the sea urchins fed these experimental diets ranged from 0.15 to 3.01 mg/kg dry gonad weight. The higher astaxanthin levels (>2.90 mg/kg) were found in the gonads of the sea urchins fed the diets HP1 (containing 380 mg/kg of astaxanthins, mostly mono- and diesters) and AST1 (containing 385 mg/kg of synthetic astaxanthin). The lowest astaxanthin level (0.15 mg/kg) was detected in the gonads of the sea urchins fed the diet CZ2 (containing 98 mg/kg of astaxanthins, mostly diesters). Furthermore, the highest canthaxanthin level (7.48 mg/kg) was found in the gonads of the sea urchins fed the diet CZ1 (containing 387 mg/kg of astaxanthins and 142 mg/kg of canthaxanthin), suggesting that astaxanthins, especially astaxanthin esters, might not be assimilated as easily as canthaxanthin by the sea urchins. Our results show that sea urchins fed diets containing astaxanthin pigments show higher incorporation of these known antioxidant constituents, with the resultant seafood products therefore being of potential higher nutritive value.

  11. Chiral conducting polymers.

    Science.gov (United States)

    Kane-Maguire, Leon A P; Wallace, Gordon G

    2010-07-01

    This critical review describes the preparation and properties of a relatively new class of chiral macromolecules, namely chiral conducting polymers. It focuses in particular on examples based on polypyrrole, polythiophene and polyaniline. They possess remarkable properties, combining not only chirality with electrical conductivity but also the ability to undergo facile redox and pH switching. These unique properties have opened up a range of exciting new potential applications, including as chiral sensors, as novel stationary phases for chiral separations, and as chiral electrodes for electrochemical asymmetric synthesis (153 references).

  12. Isolation and selection of new astaxanthin producing strains of Xanthophyllomyces dendrorhous.

    Science.gov (United States)

    Libkind, Diego; Moliné, Martín; Tognetti, Celia

    2012-01-01

    Astaxanthin is a xanthophyll pigment of high economic value for its use as a feeding component in aquaculture. Xanthophyllomyces dendrorhous is a basidiomycetous fungi able to synthesize astaxanthin as its major carotenoid, and the only known yeast species bearing the capability to produce this type of carotenoid. Recently, the habitat and intraspecific variability of this species have been found to be wider than previously expected, encouraging the search for new wild strains with potential biotechnological applications. Here we describe effective procedures for isolation of X. dendrorhous from environmental samples, accurate identification of the strains, analysis of their astaxanthin content, and proper conservation of the isolates.

  13. Simultaneous production of triacylglycerol and high-value carotenoids by the astaxanthin-producing oleaginous green microalga Chlorella zofingiensis.

    Science.gov (United States)

    Liu, Jin; Mao, Xuemei; Zhou, Wenguang; Guarnieri, Michael T

    2016-08-01

    The production of lipids and astaxanthin, a high-value carotenoid, by Chlorella zofingiensis was investigated under different culture conditions. Comparative analysis revealed a good correlation between triacylglycerol (TAG) and astaxanthin accumulation in C. zofingiensis. Stress conditions promoted cell size and weight and induced the accumulation of neutral lipids, especially TAG and astaxanthin, with a concomitant decrease in membrane lipids. The highest contents of TAG and astaxanthin achieved were 387 and 4.89mgg(-1) dry weight, respectively. A semi-continuous culture strategy was developed to optimize the TAG and astaxanthin productivities, which reached 297 and 3.3mgL(-1)day(-1), respectively. Additionally, astaxanthin accumulation was enhanced by inhibiting de novo fatty acid biosynthesis. In summary, our study represents a pioneering work of utilizing Chlorella for the integrated production of lipids and high-value products and C. zofingiensis has great potential to be a promising production strain and serve as an emerging oleaginous model alga.

  14. Cloning and selection of carotenoid ketolase genes for the engineering of high-yield astaxanthin in plants.

    Science.gov (United States)

    Huang, Junchao; Zhong, Yujuan; Sandmann, Gerhard; Liu, Jin; Chen, Feng

    2012-08-01

    β-Carotene ketolase (BKT) catalyzes the rate-limiting steps for the biosynthesis of astaxanthin. Several bkt genes have been isolated and explored to modify plant carotenoids to astaxanthin with limited success. In this study, five algal BKT cDNAs were isolated and characterized for the engineering of high-yield astaxanthin in plants. The products of the cDNAs showed high similarity in sequence and enzymatic activity of converting β-carotene into canthaxanthin. However, the enzymes exhibited extremely different activities in converting zeaxanthin into astaxanthin. Chlamydomonas reinhardtii BKT showed the highest conversion rate (ca 85%), whereas, Neochloris wimmeri BKT exhibited very poor activity of ketolating zeaxanthin. Expression of C. reinhardtii BKT in tobacco led to a twofold increase of total carotenoids in the leaves with astaxanthin being the predominant. The bkt genes described here provide a valuable resource for metabolic engineering of plants as cell factories for astaxanthin production.

  15. Simultaneous Production of Triacylglycerol and High-Value Carotenoids by the Astaxanthin-Producing Oleaginous Green Microalga Chlorella zofingiensis

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jin; Mao, Xuemei; Zhou, Wenguang; Guarnieri, Michael T.

    2016-08-01

    The production of lipids and astaxanthin, a high-value carotenoid, by Chlorella zofingiensis was investigated under different culture conditions. Comparative analysis revealed a good correlation between triacylglycerol (TAG) and astaxanthin accumulation in C. zofingiensis. Stress conditions promoted cell size and weight and induced the accumulation of neutral lipids, especially TAG and astaxanthin, with a concomitant decrease in membrane lipids. The highest contents of TAG and astaxanthin achieved were 387 and 4.89 mg g-1 dry weight, respectively. A semi-continuous culture strategy was developed to optimize the TAG and astaxanthin productivities, which reached 297 and 3.3 mg L-1 day-1, respectively. Additionally, astaxanthin accumulation was enhanced by inhibiting de novo fatty acid biosynthesis. In summary, our study represents a pioneering work of utilizing Chlorella for the integrated production of lipids and high-value products and C. zofingiensis has great potential to be a promising production strain and serve as an emerging oleaginous model alga.

  16. The effect of temperature on cell growth and astaxanthin accumulation of Haematococcus pluvialis during a light-dark cyclic cultivation.

    Science.gov (United States)

    Wan, Minxi; Zhang, Jingkui; Hou, Dongmei; Fan, Jianhua; Li, Yuanguang; Huang, Jianke; Wang, Jun

    2014-09-01

    Haematococcus pluvialis is the best source of natural astaxanthin known as "the king of antioxidants". The mass outdoor culture is the most workable strategy for astaxanthin production, but the effects of daytime and night temperatures on the biomass concentration and astaxanthin content of H. pluvialis have received little attention. This study indicated that, raising the daytime or night temperature could stimulate night accumulation of astaxanthin until temperature up to 28°C; the night biomass loss increased firstly and then decreased along with the daytime temperature reducing; decreasing the night temperature can lessen night biomass loss; the daytime temperature of 28°C and the night temperature below 28°C were optimal for achieving high biomass and astaxanthin content. Subsequently, the outdoor culture strategy has been improved and can increase the net biomass and astaxanthin productivities by 5 and 2.9-fold as compared to the former strategy.

  17. Isomer Energy Source for Space Propulsion Systems

    Science.gov (United States)

    2004-03-01

    Nuclear Thermal Rocket PBR Particle-Bed Reactor SNTP Space Nuclear Thermal Propulsion TIC Triggered Isomer Core TIHE Triggered Isomer Heat...energy in a nuclear thermal rocket (NTR) configuration. This includes study of the current state of triggered isomer research, an investigation of 4... thermal rocket this means that heat from the reactive core must be prevented from raising the temperature of the propellant prior to its release from

  18. High spin isomer beam line at RIKEN

    Energy Technology Data Exchange (ETDEWEB)

    Kishida, T.; Ideguchi, E.; Wu, H.Y. [Institute of Physical and Chemical Research, Saitama (Japan)] [and others

    1996-12-31

    Nuclear high spin states have been the subject of extensive experimental and theoretical studies. For the production of high spin states, fusion reactions are usually used. The orbital angular momentum brought in the reaction is changed into the nuclear spin of the compound nucleus. However, the maximum induced angular momentum is limited in this mechanism by the maximum impact parameter of the fusion reaction and by the competition with fission reactions. It is, therefore, difficult to populate very high spin states, and as a result, large {gamma}-detector arrays have been developed in order to detect subtle signals from such very high spin states. The use of high spin isomers in the fusion reactions can break this limitation because the high spin isomers have their intrinsic angular momentum, which can bring the additional angular momentum without increasing the excitation energy. There are two methods to use the high spin isomers for secondary reactions: the use of the high spin isomers as a target and that as a beam. A high spin isomer target has already been developed and used for several experiments. But this method has an inevitable shortcoming that only {open_quotes}long-lived{close_quotes} isomers can be used for a target: {sup 178}Hf{sup m2} (16{sup +}) with a half-life of 31 years in the present case. By developing a high spin isomer beam, the authors can utilize various short-lived isomers with a short half-life around 1 {mu}s. The high spin isomer beam line of RIKEN Accelerator Facility is a unique apparatus in the world which provides a high spin isomer as a secondary beam. The combination of fusion-evaporation reaction and inverse kinematics are used to produce high spin isomer beams; in particular, the adoption of `inverse kinematics` is essential to use short-lived isomers as a beam.

  19. Excited state dynamics of the astaxanthin radical cation

    Science.gov (United States)

    Amarie, Sergiu; Förster, Ute; Gildenhoff, Nina; Dreuw, Andreas; Wachtveitl, Josef

    2010-07-01

    Femtosecond transient absorption spectroscopy in the visible and NIR and ultrafast fluorescence spectroscopy were used to examine the excited state dynamics of astaxanthin and its radical cation. For neutral astaxanthin, two kinetic components corresponding to time constants of 130 fs (decay of the S 2 excited state) and 5.2 ps (nonradiative decay of the S 1 excited state) were sufficient to describe the data. The dynamics of the radical cation proved to be more complex. The main absorption band was shifted to 880 nm (D 0 → D 3 transition), showing a weak additional band at 1320 nm (D 0 → D 1 transition). We found, that D 3 decays to the lower-lying D 2 within 100 fs, followed by a decay to D 1 with a time constant of 0.9 ps. The D 1 state itself exhibited a dual behavior, the majority of the population is transferred to the ground state in 4.9 ps, while a small population decays on a longer timescale of 40 ps. Both transitions from D 1 were found to be fluorescent.

  20. Sequential Heterotrophy-Dilution-Photoinduction Cultivation of Haematococcus pluvialis for efficient production of astaxanthin.

    Science.gov (United States)

    Wan, Minxi; Zhang, Zhen; Wang, Jun; Huang, Jianke; Fan, Jianhua; Yu, Anquan; Wang, Weiliang; Li, Yuanguang

    2015-12-01

    A novel cultivation strategy called "Sequential Heterotrophy-Dilution-Photoinduction" was successfully applied in the cultivation of Haematococcus pluvialis to produce astaxanthin effectively. Cells were first cultivated heterotrophically to achieve a high cell density, then were diluted to a suitable concentration and switched to a favorable environment for cells acclimation. Finally, the culture was transferred to high light environment for astaxanthin accumulation. By this strategy, the dry cell weight of 26 g/L and biomass productivity of 64.1mg/L/h were obtained in heterotrophy stage which surpassed ever before reported in literatures. Meanwhile, the cells could accumulate considerable astaxanthin up to 4.6% of dry cell weight after 10 days of photoinduction. Furthermore, the application prospects of the strategy were confirmed further by outdoor experiments. Therefore, this novel strategy provided a promising approach for high-efficient production of natural astaxanthin from H. pluvialis to meet the huge demand of this high value product.

  1. Production, extraction, and quantification of astaxanthin by Xanthophyllomyces dendrorhous or Haematococcus pluvialis: standardized techniques.

    Science.gov (United States)

    Domínguez-Bocanegra, Alma Rosa

    2012-01-01

    For many years, benefits and disadvantages of pigments production either by microalgae or yeasts have been under analysis. In this contribution we shall deal with Xanthophyllomyces dendrorhous (formerly Phaffia rhodozyma) and Haematococcus pluvialis, which are known as major prominent microorganisms able to synthesize astaxanthin pigment. Then, the usual trend is to look for optimal conditions to conduct astaxanthin synthesis. From one side, pigment production by H. pluvialis is promoted under cellular stress conditions like nutrient deprivation, exposition to high light intensity, aeration. On the other side, X. dendrorhous is able to show significant increase in astaxanthin synthesis when grown in natural carbon sources like coconut milk, grape juice. The main aim of this chapter is to describe optimal environmental conditions for astaxanthin production by X. dendrorhous or H. pluvialis.

  2. Utilization of mustard waste isolates for improved production of astaxanthin by Xanthophyllomyces dendrorhous.

    Science.gov (United States)

    Tinoi, J; Rakariyatham, N; Deming, R L

    2006-04-01

    Astaxanthin production in the wild strain Xanthophyllomyces dendrorhous TISTR 5730 was investigated using different mustard waste media, including mustard waste residue extract (MRE), mustard waste residue hydrolysate (MRH), mustard waste precipitated extract (MPE), and mustard waste precipitated hydrolysate (MPH). The growth of X. dendrorhous and the production of astaxanthin were dependent on the type and initial concentrations of mustard waste media. The MPH medium was the best substrate resulting in yields of biomass and astaxanthin of 19.6 g/L and 25.8 mg/L, respectively, under optimal conditions. MPH medium improved astaxanthin production 11-fold compared to the commonly used commercial yeast malt medium, and 1.3-2.1-fold compared to other mustard waste media.

  3. Optical absorption spectra of Ag-11 isomers

    DEFF Research Database (Denmark)

    Martinez, Jose Ignacio; Fernandez, E. M.

    2009-01-01

    The optical absorption spectra of the three most; stable structural isomers of the Ag-11 cluster were calculated using the time-dependent, density functional theory within the Casida formalism. The slightly different, spectra, of the isomers may permit the identification of the ground-stale confi......The optical absorption spectra of the three most; stable structural isomers of the Ag-11 cluster were calculated using the time-dependent, density functional theory within the Casida formalism. The slightly different, spectra, of the isomers may permit the identification of the ground...

  4. Increase in the astaxanthin synthase gene (crtS) dose by in vivo DNA fragment assembly in Xanthophyllomyces dendrorhous

    OpenAIRE

    Contreras, Gabriela; Barahona, Salvador; Rojas, María Cecilia; Baeza, Marcelo; Cifuentes, Víctor; Alcaíno, Jennifer

    2013-01-01

    Background Xanthophyllomyces dendrorhous is a basidiomycetous yeast that is relevant to biotechnology, as it can synthesize the carotenoid astaxanthin. However, the astaxanthin levels produced by wild-type strains are low. Although different approaches for promoting increased astaxanthin production have been attempted, no commercially competitive results have been obtained thus far. A promising alternative to facilitate the production of carotenoids in this yeast involves the use of genetic m...

  5. EXTRACTION OF ASTAXANTHIN ESTERS FROM SHRIMP WASTE BY CHEMICAL AND MICROBIAL METHODS

    OpenAIRE

    A. Khanafari, A. Saberi, M. Azar, Gh. Vosooghi, Sh. Jamili, B. Sabbaghzadeh

    2007-01-01

    The carotenoid pigments specifically astaxanthin has many significant applications in food, pharmaceutical and cosmetic industries. The goal of this research was the extraction of Astaxanthin from a certain Persian Gulf shrimp species waste (Penaeus semisulcatus), purification and identification of the pigment by chemical and microbial methods. Microbial fermentation was obtained by inoculation of two Lactobacillus species Lb. plantarum and Lb. acidophilus in the medium culture containing shr...

  6. Near-Infrared Hyper-spectral Image Analysis of Astaxanthin Concentration in Fish Feed Coating

    DEFF Research Database (Denmark)

    Ljungqvist, Martin Georg; Ersbøll, Bjarne Kjær; Kobayashi, K.;

    2012-01-01

    The aim of this study was to investigate the possibility of predicting concentration levels of synthetic astaxanthin coating of aquaculture feed pellets by hyper-spectral image analysis in the near infra-red (NIR) range and optical filter design. The imaging devices used were a Videometer...... for prediction of the concentration level. The results show that it is possible to predict the level of synthetic astaxanthin coating using either hyper-spectral imaging or three bandpass filters (BPF)....

  7. Anti-inflammatory Effect of Astaxanthin on the Sickness Behavior Induced by Diabetes Mellitus.

    Science.gov (United States)

    Ying, Chang-jiang; Zhang, Fang; Zhou, Xiao-yan; Hu, Xiao-tong; Chen, Jing; Wen, Xiang-ru; Sun, Ying; Zheng, Kui-yang; Tang, Ren-xian; Song, Yuan-jian

    2015-10-01

    Chronic inflammation appears to play a critical role in sickness behavior caused by diabetes mellitus. Astaxanthin has been used in treating diabetes mellitus and diabetic complications because of its neuroprotective and anti-inflammatory actions. However, whether astaxanthin can improve sickness behavior induced by diabetes and its potential mechanisms are still unknown. The aim of this study was to investigate the effects of astaxanthin on diabetes-elicited abnormal behavior in mice and its corresponding mechanisms. An experimental diabetic model was induced by streptozotocin (150 mg/kg) and astaxanthin (25 mg/kg/day) was provided orally for 10 weeks. Body weight and water consumption were measured, and the sickness behavior was evaluated by the open field test (OFT) and closed field test (CFT). The expression of glial fibrillary acidic protein (GFAP) was measured, and the frontal cortical cleaved caspase-3 positive cells, interleukin-6 (IL-6), and interleukin-1β (IL-1β) expression levels were also investigated. Furthermore, cystathionine β-synthase (CBS) in the frontal cortex was detected to determine whether the protective effect of astaxanthin on sickness behavior in diabetic mice is closely related to CBS. As expected, we observed that astaxanthin improved general symptoms and significantly increase horizontal distance and the number of crossings in the OFT and CFT. Furthermore, data showed that astaxanthin could decrease GFAP-positive cells in the brain and down-regulate the cleaved caspase-3, IL-6, and IL-1β, and up-regulate CBS in the frontal cortex. These results suggest that astaxanthin provides neuroprotection against diabetes-induced sickness behavior through inhibiting inflammation, and the protective effects may involve CBS expression in the brain.

  8. Expression of carotenogenic genes and astaxanthin production in Xanthophyllomyces dendrorhous as a function of oxygen tension.

    Science.gov (United States)

    Wu, Wei; Lu, Mingbo; Yu, Longjiang

    2011-01-01

    This report gives an insight into the specific changes in the transcription of four key carotenogenic genes [encoding geranylgeranyl diphosphate synthase (crtE), phytoene desaturase (crtI), phytoene synthase lycopene cyclase (crtYB), and astaxanthin synthase (ast), respectively] in Xanthophyllomyces dendrorhous cultures, with regard to dissolved oxygen (DO) contents of 10%, 25%, and 40% air saturation, respectively. 25% DO proved to be the most beneficial for yeast growth, transcription of carotenogenic genes, and astaxanthin content.

  9. Astaxanthin prevents and reverses diet-induced insulin resistance and steatohepatitis in mice: A comparison with vitamin E.

    Science.gov (United States)

    Ni, Yinhua; Nagashimada, Mayumi; Zhuge, Fen; Zhan, Lili; Nagata, Naoto; Tsutsui, Akemi; Nakanuma, Yasuni; Kaneko, Shuichi; Ota, Tsuguhito

    2015-11-25

    Hepatic insulin resistance and nonalcoholic steatohepatitis (NASH) could be caused by excessive hepatic lipid accumulation and peroxidation. Vitamin E has become a standard treatment for NASH. However, astaxanthin, an antioxidant carotenoid, inhibits lipid peroxidation more potently than vitamin E. Here, we compared the effects of astaxanthin and vitamin E in NASH. We first demonstrated that astaxanthin ameliorated hepatic steatosis in both genetically (ob/ob) and high-fat-diet-induced obese mice. In a lipotoxic model of NASH: mice fed a high-cholesterol and high-fat diet, astaxanthin alleviated excessive hepatic lipid accumulation and peroxidation, increased the proportion of M1-type macrophages/Kupffer cells, and activated stellate cells to improve hepatic inflammation and fibrosis. Moreover, astaxanthin caused an M2-dominant shift in macrophages/Kupffer cells and a subsequent reduction in CD4(+) and CD8(+) T cell recruitment in the liver, which contributed to improved insulin resistance and hepatic inflammation. Importantly, astaxanthin reversed insulin resistance, as well as hepatic inflammation and fibrosis, in pre-existing NASH. Overall, astaxanthin was more effective at both preventing and treating NASH compared with vitamin E in mice. Furthermore, astaxanthin improved hepatic steatosis and tended to ameliorate the progression of NASH in biopsy-proven human subjects. These results suggest that astaxanthin might be a novel and promising treatment for NASH.

  10. Multiple improvement of astaxanthin biosynthesis in Xanthophyllomyces dendrorhous by a combination of conventional mutagenesis and metabolic pathway engineering.

    Science.gov (United States)

    Gassel, Sören; Schewe, Hendrik; Schmidt, Isabell; Schrader, Jens; Sandmann, Gerhard

    2013-04-01

    Xanthophyllomyces dendrorhous (Phaffia rhodozyma) is the only yeast or fungus that synthesizes the commercially attractive carotenoid astaxanthin. For a suitable bioprocess, the wild type has to be modified for increasing biomass content. To achieve this, a two step strategy has been followed. At first, random mutagenesis was applied leading to colonies with substantially higher astaxanthin content. Then, the resulting strain was genetically engineered by targeting limiting reactions for further enhancement of astaxanthin biosynthesis. This combinatorial approach together with selection of an appropriate growth medium resulted in highest astaxanthin biomass contents reported to date for X. dendrorhous. In a fermenter culture, its maximum content was 9.7 mg/g dry weight.

  11. Studies on optimization of nitrogen sources for astaxanthin production by Phaffia rhodozyma

    Institute of Scientific and Technical Information of China (English)

    NI Hui; CHEN Qi-he; RUAN Hui; YANG Yuan-fan; LI Li-jun; WU Guang-bin; HU Yang; HE Guo-qing

    2007-01-01

    Fermentation of Phaffia rhodozyma is a major method for producing astaxanthin, an important pigment with industrial and pharmaceutical application. To improve astaxanthin productivity, single factor and mixture design experiments were used to investigate the effects of nitrogen source on Phaffia rhodozyma cultivation and astaxanthin production. Results of single factor experiments showed nitrogen source could significantly affect P. rhodozyma cultivation with respect to carbon source utilization,yeast growth and astaxanthin accumulation. Further studies of mixture design experiments using (NH4)2SO4, KNO3 and beef extract as nitrogen sources indicated that the proportion of three nitrogen sources was very important to astaxanthin production.Validation experiments showed that the optimal nitrogen source was composed of 0.28 g/L (NH4)2SO4, 0.49 g/L KNO3 and 1.19g/L beef extract. The kinetic characteristics of batch cultivation were investigated in a 5-L pH-stat fermentor. The maximum amount of biomass and highest astaxanthin yield in terms of volume and in terms of biomass were 7.71 mg/L and 1.00 mg/g,respectively.

  12. Determination of astaxanthin in Haematococcus pluvialis by first-order derivative spectrophotometry.

    Science.gov (United States)

    Liu, Xiao Juan; Juan, Liu Xiao; Wu, Ying Hua; Hua, Wu Ying; Zhao, Li Chao; Chao, Zhao Li; Xiao, Su Yao; Yao, Xiao Su; Zhou, Ai Mei; Mei, Zhou Ai; Liu, Xin; Xin, Liu

    2011-01-01

    A highly selective, convenient, and precise method, first-order derivative spectrophotometry, was applied for the determination of astaxanthin in Haematococcus pluvialis. Ethyl acetate and ethanol (1:1, v/v) were found to be the best extraction solvent tested due to their high efficiency and low toxicity compared with nine other organic solvents. Astaxanthin coexisting with chlorophyll and beta-carotene was analyzed by first-order derivative spectrophotometry in order to optimize the conditions for the determination of astaxanthin. The results show that when detected at 432 nm, the interfering substances could be eliminated. The dynamic linear range was 2.0-8.0 microg/mL, with a correlation coefficient of 0.9916. The detection threshold was 0.41 microg/mL. The RSD for the determination of astaxanthin was in the range of 0.01-0.06%; the results of recovery test were 98.1-108.0%. The statistical analysis between first-order derivative spectrophotometry and HPLC by T-testing did not exceed their critical values, revealing no significant differences between these two methods. It was proved that first-order derivative spectrophotometry is a rapid and convenient method for the determination of astaxanthin in H. pluvialis that can eliminate the negative effect resulting from the coexistence of astaxanthin with chlorophyll and beta-carotene.

  13. Effects of Selected Polysorbate and Sucrose Ester Emulsifiers on the Physicochemical Properties of Astaxanthin Nanodispersions

    Directory of Open Access Journals (Sweden)

    Navideh Anarjan

    2013-01-01

    Full Text Available The effects of selected nonionic emulsifiers on the physicochemical characteristics of astaxanthin nanodispersions produced by an emulsification/evaporation technique were studied. The emulsifiers used were polysorbates (Polysorbate 20, Polysorbate 40, Polysorbate 60 and Polysorbate 80 and sucrose esters of fatty acids (sucrose laurate, palmitate, stearate and oleate. The mean particle diameters of the nanodispersions ranged from 70 nm to 150 nm, depending on the emulsifier used. In the prepared nanodispersions, the astaxanthin particle diameter decreased with increasing emulsifier hydrophilicity and decreasing carbon number of the fatty acid in the emulsifier structure. Astaxanthin nanodispersions with the smallest particle diameters were produced with Polysorbate 20 and sucrose laurate among the polysorbates and the sucrose esters, respectively. We also found that the Polysorbate 80- and sucrose oleate-stabilized nanodispersions had the highest astaxanthin losses (i.e., the lowest astaxanthin contents in the final products among the nanodispersions. This work demonstrated the importance of emulsifier type in determining the physicochemical characteristics of astaxanthin nano-dispersions.

  14. Baryons and Chiral Symmetry

    CERN Document Server

    Liu, Keh-Fei

    2016-01-01

    The relevance of chiral symmetry in baryons is highlighted in three examples in the nucleon spectroscopy and structure. The first one is the importance of chiral dynamics in understanding the Roper resonance. The second one is the role of chiral symmetry in the lattice calculation of $\\pi N \\sigma$ term and strangeness. The third one is the role of chiral $U(1)$ anomaly in the anomalous Ward identity in evaluating the quark spin and the quark orbital angular momentum. Finally, the chiral effective theory for baryons is discussed.

  15. Chiral Separation by Capillary Zone Electrophoresis Used Cyclodextrins and Their Derivatives as Chiral Selector

    Institute of Scientific and Technical Information of China (English)

    HOU; JingGuo

    2001-01-01

    Capillary zone electrophoresis (CZE) is a very pronising analytical technique for the optical isomer resolution of the compounds studied. The drawbacks of the techniques such as HPLC [1] were sophisticated stationary phases and/or the relatively high quantity of the chiral agent in the mobile phase, which do not exist in CZE. The capillary electrophoresis (CE) method can offer advantages on lower consumption of analyte and background electrolyte (BGE), shorter analysis time, and higher efficiencies [2-3]  ……

  16. Chiral Rotational Spectroscopy

    CERN Document Server

    Cameron, Robert P; Barnett, Stephen M

    2015-01-01

    We introduce chiral rotational spectroscopy: a new technique that enables the determination of the individual optical activity polarisability components $G_{XX}'$, $G_{YY}'$, $G_{ZZ}'$, $A_{X,YZ}$, $A_{Y,ZX}$ and $A_{Z,XY}$ of chiral molecules, in a manner that reveals the enantiomeric constitution of a sample whilst yielding an incisive signal even for a racemate. Chiral rotational spectroscopy could find particular use in the analysis of molecules that are chiral by virtue of their isotopic constitution and molecules with multiple chiral centres. The principles that underpin chiral rotational spectroscopy can also be exploited in the search for molecular chirality in space, which, if found, may add weight to hypotheses that biological homochirality and indeed life itself are of cosmic origin.

  17. On chiral and non chiral 1D supermultiplets

    Energy Technology Data Exchange (ETDEWEB)

    Toppan, Francesco, E-mail: toppan@cbpf.b [Centro Brasileiro de Pesquisas Fisicas (TEO/CBPF), Rio de Janeiro, RJ (Brazil). Coordenacao de Fisica Teorica

    2011-07-01

    In this talk I discuss and clarify some issues concerning chiral and non chiral properties of the one-dimensional supermultiplets of the N-extended supersymmetry. Quaternionic chirality can be defined for N = 4, 5, 6, 7, 8. Octonionic chirality for N = 8 and beyond. Inequivalent chiralities only arise when considering several copies of N = 4 or N = 8 supermultiplets. (author)

  18. On the calculation of Mossbauer isomer shift

    NARCIS (Netherlands)

    Filatov, Michael

    2007-01-01

    A quantum chemical computational scheme for the calculation of isomer shift in Mossbauer spectroscopy is suggested. Within the described scheme, the isomer shift is treated as a derivative of the total electronic energy with respect to the radius of a finite nucleus. The explicit use of a finite nuc

  19. Chiral symmetry and chiral-symmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Peskin, M.E.

    1982-12-01

    These lectures concern the dynamics of fermions in strong interaction with gauge fields. Systems of fermions coupled by gauge forces have a very rich structure of global symmetries, which are called chiral symmetries. These lectures will focus on the realization of chiral symmetries and the causes and consequences of thier spontaneous breaking. A brief introduction to the basic formalism and concepts of chiral symmetry breaking is given, then some explicit calculations of chiral symmetry breaking in gauge theories are given, treating first parity-invariant and then chiral models. These calculations are meant to be illustrative rather than accurate; they make use of unjustified mathematical approximations which serve to make the physics more clear. Some formal constraints on chiral symmetry breaking are discussed which illuminate and extend the results of our more explicit analysis. Finally, a brief review of the phenomenological theory of chiral symmetry breaking is presented, and some applications of this theory to problems in weak-interaction physics are discussed. (WHK)

  20. Dynamic Kinetic Asymmetric Amination of Alcohols: From A Mixture of Four Isomers to Diastereo- and Enantiopure α-Branched Amines.

    Science.gov (United States)

    Rong, Zi-Qiang; Zhang, Yao; Chua, Raymond Hong Bing; Pan, Hui-Jie; Zhao, Yu

    2015-04-22

    The first dynamic kinetic asymmetric amination of alcohols via borrowing hydrogen methodology is presented. Under the cooperative catalysis by an iridium complex and a chiral phosphoric acid, α-branched alcohols that exist as a mixture of four isomers undergo racemization by two orthogonal mechanisms and are converted to diastereo- and enantiopure amines bearing adjacent stereocenters. The preparation of diastereo- and enantiopure 1,2-amino alcohols is also realized using this catalytic system.

  1. Commercial astaxanthin production derived by green alga Haematococcus pluvialis: A microalgae process model and a techno-economic assessment all through production line.

    NARCIS (Netherlands)

    Panis, Georgios; Rosales Carreon, J.

    2016-01-01

    The freshwater green microalgal strain Haematococcus pluvialis is the richest source for the production of astaxanthin. Astaxanthin is member of the xanthophyll family of carotenoids and constitutes the highest value product derived by microalgae. So far, algal astaxanthin amounts to < 1% of the glo

  2. Extrinsic electromagnetic chirality in metamaterials

    OpenAIRE

    Plum, E.; Fedotov, V. A.; Zheludev, N. I.

    2009-01-01

    Three- and two-dimensional chirality arising from the mutual orientation of non-chiral planar metamaterial structures and the incident electromagnetic wave (extrinsic chirality) lead to pronounced optical activity, circular dichroism and asymmetric transmission indistinguishable from those seen in media consisting of three- and two-dimensionally chiral molecules (intrinsic chirality).

  3. Gelation induced supramolecular chirality: chirality transfer, amplification and application.

    Science.gov (United States)

    Duan, Pengfei; Cao, Hai; Zhang, Li; Liu, Minghua

    2014-08-14

    Supramolecular chirality defines chirality at the supramolecular level, and is generated from the spatial arrangement of component molecules assembling through non-covalent interactions such as hydrogen bonding, van der Waals interactions, π-π stacking, hydrophobic interactions and so on. During the formation of low molecular weight gels (LMWGs), one kind of fascinating soft material, one frequently encounters the phenomenon of chirality as well as chiral nanostructures, either from chiral gelators or even achiral gelators. A view of gelation-induced supramolecular chirality will be very helpful to understand the self-assembly process of the gelator molecules as well as the chiral structures, the regulation of the chirality in the gels and the development of the "smart" chiral materials such as chiroptical devices, catalysts and chiral sensors. It necessitates fundamental understanding of chirality transfer and amplification in these supramolecular systems. In this review, recent progress in gelation-induced supramolecular chirality is discussed.

  4. Putative benefits of microalgal astaxanthin on exercise and human health

    Directory of Open Access Journals (Sweden)

    Marcelo P. Barros

    2011-04-01

    Full Text Available Astaxanthin (ASTA is a pinkish-orange carotenoid produced by microalgae, but also commonly found in shrimp, lobster and salmon, which accumulate ASTA from the aquatic food chain. Numerous studies have addressed the benefits of ASTA for human health, including the inhibition of LDL oxidation, UV-photoprotection and prophylaxis of bacterial stomach ulcers. ASTA is recognized as a powerful scavenger of reactive oxygen species (ROS, especially those involved in lipid peroxidation. Both aerobic and anaerobic exercise are closely related to overproduction of ROS in muscle tissue. Post-exercise inflammatory processes can even exacerbate the oxidative stress imposed by exercise. Thus, ASTA is suggested here as a putative nutritional alternative/coadjutant for antioxidant therapy to afford additional protection to muscle tissues against oxidative damage induced by exercise, as well as for an (overall integrative redox re-balance and general human health.

  5. Encapsulation of astaxanthin-rich Xanthophyllomyces dendrorhous for antioxidant delivery.

    Science.gov (United States)

    Lee, Ji-Soo; Park, Sun-Ah; Chung, Donghwa; Lee, Hyeon Gyu

    2011-10-01

    Calcium alginate gel (CAG) beads were used to entrap the antioxidant astaxanthin-rich Xanthophyllomyces dendrorhous (ASX) by ionic gelation. ASX-CAG bead entrapment efficiency and release behavior, as influenced by alginate and CaCl(2) concentration and hardening time, were investigated. The optimized bead preparation conditions that gave rise to an efficient ASX release pattern were 1.5% alginate, 50mM CaCl(2), and a 5min hardening time. The antioxidant activity of non-encapsulated ASX was maintained for 4 days and then sharply decreased, whereas encapsulated ASX was maintained for 6 days. These results revealed that physical entrapment of ASX within CAG beads could be an effective technique for protecting the antioxidant activity of ASX from lipid peroxidation.

  6. Effects of iron electrovalence and species on growth and astaxanthin production of Haematococcus pluvialis

    Science.gov (United States)

    Cai, Minggang; Li, Zhe; Qi, Anxiang

    2009-05-01

    To increase the cell concentration and the accumulation of astaxanthin in the cultivation of Haematococcus pluvialis, effects of different iron electrovalencies (Fe2+-EDTA and Fe3+-EDTA) and species (Fe-EDTA, Fe(OH){x/32x} and FeC6H5O7) addition on cell growth and accumulation of astaxanthin were studied. Results show that different iron electrovalencies have various effects on cell growth and astaxanthin accumulation of H. pluvialis. Compared with Fe3+-EDTA, Fe2+-EDTA stimulate more effectively the formation of astaxanthin. The maximum astaxanthin content (30.70 mg/g biomass cell) was obtained under conditions of 18 μmol/L Fe2+-EDTA, despite the lower cell density (2.3×105 cell/ml) in such condition. Fe3+-EDTA is more effective than Fe2+-EDTA in improving the cell growth. Especially, the maximal steady-state cell density, 2.9×105 cell/ml was obtained at 18 μmol/L Fe3+-EDTA addition. On the other hand, all the various species of iron (EDTA-Fe, Fe(OH){x/32x}, FeC6H5O7) are capable to improve the growth of the algae and astaxanthin production. Among the three iron species, FeC6H5O7 performed the best. Under the condition of a higher concentration (36 μmol/L) of FeC6H5O7, the cell density and astaxanthin production is 2 and 7 times higher than those of iron-limited group, respectively. The present study demonstrates that the effects of the stimulation with different iron species increased in the order of FeC6H5O7, Fe(OH){x/32x} and EDTA-Fe.

  7. Effects of iron electrovalence and species on growth and astaxanthin production of Haematococcus pluvialis

    Institute of Scientific and Technical Information of China (English)

    CAI Minggang; LI Zhe; QI Anxiang

    2009-01-01

    To increase the cell concentration and the accumulation of astaxanthin in the cultivation of Haematococcus pluvialis, effects of different iron eleetrovalencies (Fe2+-EDTA and Fe3+-EDTA) and species (Fe-EDTA, Fe(OH)32x and FeC6H5O7) addition on cell growth and accumulation of astaxanthin were studied. Results show that different iron electrovalencies have various effects on cell growth and astaxanthin accumulation of H. pluvialis. Compared with Fe3+-EDTA, Fe2+-EDTA stimulate more effectively the formation of astaxanthin. The maximum astaxanthin content (30.70 mg/g biomass cell)was obtained under conditions of 18 μmol/L Fe2+-EDTA, despite the lower cell density (2.3x105 cell/ml)in such condition. Fe3+-EDTA is more effective than Fe2+-EDTA in improving the cell growth. Especially,the maximal steady-state cell density, 2.9x105 cell/ml was obtained at 18 μmol/L Fe3+-EDTA addition. On the other hand, all the various species of iron (EDTA-Fe, Fe(OH)32x, FeC6H5O7) are capable to improve the growth of the algae and astaxanthin production. Among the three iron species, FeC6H5O7 performed the best. Under the condition of a higher concentration (36 μmol/L) of FEC6H5O7, the cell density and astaxanthin production is 2 and 7 times higher than those of iron-limited group, respectively. The present study demonstrates that the effects of the stimulation with different iron species increased in the order of FeC6H5O7, Fe(OH)32x/x and EDTA-Fe.

  8. Metabolic engineering of the astaxanthin-biosynthetic pathway of Xanthophyllomyces dendrorhous.

    Science.gov (United States)

    Visser, Hans; van Ooyen, Albert J J; Verdoes, Jan C

    2003-12-01

    This review describes the different approaches that have been used to manipulate and improve carotenoid production in Xanthophyllomyces dendrorhous. The red yeast X. dendrorhous (formerly known as Phaffia rhodozyma) is one of the microbiological production systems for natural astaxanthin. Astaxanthin is applied in food and feed industry and can be used as a nutraceutical because of its strong antioxidant properties. However, the production levels of astaxanthin in wild-type isolates are rather low. To increase the astaxanthin content in X. dendrorhous, cultivation protocols have been optimized and astaxanthin-hyperproducing mutants have been obtained by screening of classically mutagenized X. dendrorhous strains. The knowledge about the regulation of carotenogenesis in X. dendrorhous is still limited in comparison to that in other carotenogenic fungi. The X. dendrorhous carotenogenic genes have been cloned and a X. dendrorhous transformation system has been developed. These tools allowed the directed genetic modification of the astaxanthin pathway in X. dendrorhous. The crtYB gene, encoding the bifunctional enzyme phytoene synthase/lycopene cyclase, was inactivated by insertion of a vector by single and double cross-over events, indicating that it is possible to generate specific carotenoid-biosynthetic mutants. Additionally, overexpression of crtYB resulted in the accumulation of beta-carotene and echinone, which indicates that the oxygenation reactions are rate-limiting in these recombinant strains. Furthermore, overexpression of the phytoene desaturase-encoding gene (crtI) showed an increase in monocyclic carotenoids such as torulene and HDCO (3-hydroxy-3',4'-didehydro-beta,-psi-carotene-4-one) and a decrease in bicyclic carotenoids such as echinone, beta-carotene and astaxanthin.

  9. Hydrogen peroxide-induced astaxanthin biosynthesis and catalase activity in Xanthophyllomyces dendrorhous.

    Science.gov (United States)

    Liu, Yuan Shuai; Wu, Jian Yong

    2006-12-01

    Xanthophyllomyces dendrorhous (formerly Phaffia rhodozyma) in shake-flask cultures was exposed to 10-20 mmol/L H(2)O(2) at various culture stages, and the astaxanthin production was significantly increased by H(2)O(2) fed at 0 or 24 h (exponential phase), but only slightly at 48 h (near stationary phase). The astaxanthin production was enhanced most significantly with double feeding of 10 mmol/L H(2)O(2) at 0 and 24 h, reaching a cellular content of 1.30 mg/g cell and a volumetric yield of 10.4 mg/L, which were 83 and 65% higher, respectively, than those of the control (0.71 mg/g cell and 6.3 mg/L). The intracellular catalase (CAT) activity was also increased after H(2)O(2) treatment. The increases in CAT and astaxanthin of cells could be detected within 4 h of H(2)O(2) treatment. The increase in the astaxanthin content of cells was concomitant with a notable decrease in the beta-carotene content. The older yeast cells at late culture stage (120 h), due perhaps in part to their higher astaxanthin contents, were more tolerant to H(2)O(2) toxicity than the younger cells (24 h). No enhancement of the astaxanthin biosynthesis was attained when H(2)O(2) was added to the yeast culture together with a sufficient amount of exogenous CAT. The results suggest that astaxanthin biosynthesis in X. dendrorhous can be stimulated by H(2)O(2) as an antioxidative response.

  10. Chiral rotational spectroscopy

    Science.gov (United States)

    Cameron, Robert P.; Götte, Jörg B.; Barnett, Stephen M.

    2016-09-01

    We introduce chiral rotational spectroscopy, a technique that enables the determination of the orientated optical activity pseudotensor components BX X, BY Y, and BZ Z of chiral molecules, in a manner that reveals the enantiomeric constitution of a sample and provides an incisive signal even for a racemate. Chiral rotational spectroscopy could find particular use in the analysis of molecules that are chiral solely by virtue of their isotopic constitution and molecules with multiple chiral centers. A basic design for a chiral rotational spectrometer together with a model of its functionality is given. Our proposed technique offers the more familiar polarizability components αX X, αY Y, and αZ Z as by-products, which could see it find use even for achiral molecules.

  11. Chiral Superfluidity for QCD

    CERN Document Server

    Kalaydzhyan, Tigran

    2014-01-01

    We argue that the strongly coupled quark-gluon plasma formed at LHC and RHIC can be considered as a chiral superfluid. The "normal" component of the fluid is the thermalized matter in common sense, while the "superfluid" part consists of long wavelength (chiral) fermionic states moving independently. We use the bosonization procedure with a finite cut-off and obtain a dynamical axion-like field out of the chiral fermionic modes. Then we use relativistic hydrodynamics for macroscopic description of the effective theory obtained after the bosonization. Finally, solving the hydrodynamic equations in gradient expansion, we find that in the presence of external electromagnetic fields or rotation the motion of the "superfluid" component gives rise to the chiral magnetic, chiral vortical, chiral electric and dipole wave effects. Latter two effects are specific for a two-component fluid, which provides us with crucial experimental tests of the model.

  12. Emerging chirality in nanoscience.

    Science.gov (United States)

    Wang, Yong; Xu, Jun; Wang, Yawen; Chen, Hongyu

    2013-04-07

    Chirality in nanoscience may offer new opportunities for applications beyond the traditional fields of chirality, such as the asymmetric catalysts in the molecular world and the chiral propellers in the macroscopic world. In the last two decades, there has been an amazing array of chiral nanostructures reported in the literature. This review aims to explore and categorize the common mechanisms underlying these systems. We start by analyzing the origin of chirality in simple systems such as the helical spring and hair vortex. Then, the chiral nanostructures in the literature were categorized according to their material composition and underlying mechanism. Special attention is paid to highlight systems with original discoveries, exceptional structural characteristics, or unique mechanisms.

  13. Astaxanthin Production by the Red Yeast (Phaffia rhodozyma, Grown on Yeast Extract Addes Coconut Water [PRODUKSI ASTAXANTHIN OLEH KAMIR MERAH (Phaffia Rhodozyma DITUMBUHKAN DALAM AIR KELAPA YANG DITAMBAHKAN EKSTRAK KAMIR

    Directory of Open Access Journals (Sweden)

    V I Meitiniarti

    2003-08-01

    Full Text Available This experiment was conducted to evaluated the effect of yeast extract addition in fresh green coconut water medium during the batch growth and astaxanthin production of Phaffia rhodozyma MUCL 31142. The addition of yeast extract (0,025% and 0,075% could increase the cell growth (37,12 g/l and 49,18 g/l, growth rate (0,061/hour and 0,074/hour, total production of astaxanthin (4,871 mg/l and 9,442 mg/l, specific concentration of astaxanthin (118,99 µg/g biomass, production rate of astaxanthin (0,042/hour and 0,088/hour, astaxanthin yield (0,236 mg/g glucose and 0,342 mg/g glucose, and glocose consumption (19,84 g/l and 26,95 g/l.

  14. Scientific Opinion on the safety and efficacy of astaxanthin (CAROPHYLL® Pink 10% CWS for salmonids and ornamental fish

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP

    2014-06-01

    Full Text Available Astaxanthin is a pigmenting carotenoid naturally occurring in plankton, crustaceans and fish. The FEEDAP Panel considers synthetic astaxanthin safe for salmonids up to 100 mg/kg complete diet. This conclusion is extrapolated to ornamental fish at the same dose. Based on a BMDL10 of 3.4 mg/kg bw per day (calculated for liver hypertrophy in female rat in a carcinogenicity study and applying an uncertainty factor of 100, it is possible to set an ADI of 0.034 mg ATX/kg bw (equivalent to 2.0 mg ATX per 60 kg person per day. The use of astaxanthin up to the maximum permitted dietary level for salmon and trout is of no concern for the safety of the consumer. Skin or eye exposure to astaxanthin is unlikely to be irritant to workers. Sensitisation is unlikely to occur subsequent to skin exposure. The risk of inhalation toxicity is minimal for the formulation under assessment, but the risk for other formulations cannot be assessed. The FEEDAP Panel considers that the use of synthetic astaxanthin (100 mg astaxanthin/kg fish feed does not pose a significant additional risk to the environment compared with natural astaxanthin. Astaxanthin is efficacious in colouring the flesh of salmonids and in pigmenting the skin of ornamental fish.

  15. Organization of astaxanthin within oil bodies of Haematococcus pluvialis studied with polarization-dependent harmonic generation microscopy.

    Science.gov (United States)

    Tokarz, Danielle; Cisek, Richard; El-Ansari, Omar; Espie, George S; Fekl, Ulrich; Barzda, Virginijus

    2014-01-01

    Nonlinear optical microscopy was used to image the localization of astaxanthin accumulation in the green alga, Haematococcus pluvialis. Polarization-in, polarization-out (PIPO) second harmonic generation (SHG) and third harmonic generation (THG) microscopy was applied to study the crystalline organization of astaxanthin molecules in light-stressed H. pluvialis in vivo. Since astaxanthin readily forms H- and J-aggregates in aqueous solutions, PIPO THG studies of astaxanthin aggregates contained in red aplanospores were compared to PIPO THG of in vitro self-assembled H- and J-aggregates of astaxanthin. The PIPO THG data clearly showed an isotropic organization of astaxanthin in red aplanospores of H. pluvialis. This is in contrast to the highly anisotropic organization of astaxanthin in synthetic H- and J-aggregates, which showed to be uniaxial. Since carotenoids in vitro preferentially form H- and J-aggregates, but in vivo form a randomly organized structure, this implies that astaxanthin undergoes a different way of packing in biological organisms, which is either due to the unique physical environment of the alga or is controlled enzymatically.

  16. Highly efficient biosynthesis of astaxanthin in Saccharomyces cerevisiae by integration and tuning of algal crtZ and bkt.

    Science.gov (United States)

    Zhou, Pingping; Ye, Lidan; Xie, Wenping; Lv, Xiaomei; Yu, Hongwei

    2015-10-01

    Astaxanthin is a highly valued carotenoid with strong antioxidant activity and has wide applications in aquaculture, food, cosmetic, and pharmaceutical industries. The market demand for natural astaxanthin promotes research in metabolic engineering of heterologous hosts for astaxanthin production. In this study, an astaxanthin-producing Saccharomyces cerevisiae strain was created by successively introducing the Haematococcus pluvialis β-carotenoid hydroxylase (crtZ) and ketolase (bkt) genes into a previously constructed β-carotene hyperproducer. Further integration of strategies including codon optimization, gene copy number adjustment, and iron cofactor supplementation led to significant increase in the astaxanthin production, reaching up to 4.7 mg/g DCW in the shake-flask cultures which is the highest astaxanthin content in S. cerevisiae reported to date. Besides, the substrate specificity of H. pluvialis CrtZ and BKT and the probable formation route of astaxanthin from β-carotene in S. cerevisiae were figured out by expressing the genes separately and in combination. The yeast strains engineered in this work provide a basis for further improving biotechnological production of astaxanthin and might offer a useful general approach to the construction of heterologous biosynthetic pathways for other natural products.

  17. Protective effect of astaxanthin on liver fibrosis through modulation of TGF-β1 expression and autophagy.

    Science.gov (United States)

    Shen, Miao; Chen, Kan; Lu, Jie; Cheng, Ping; Xu, Ling; Dai, Weiqi; Wang, Fan; He, Lei; Zhang, Yan; Chengfen, Wang; Li, Jingjing; Yang, Jing; Zhu, Rong; Zhang, Huawei; Zheng, Yuanyuan; Zhou, Yingqun; Guo, Chuanyong

    2014-01-01

    Liver fibrosis is a common pathway leading to cirrhosis and a worldwide clinical issue. Astaxanthin is a red carotenoid pigment with antioxidant, anticancer, and anti-inflammatory properties. The aim of this study was to investigate the effect of astaxanthin on liver fibrosis and its potential protective mechanisms. Liver fibrosis was induced in a mouse model using CCL4 (intraperitoneal injection, three times a week for 8 weeks), and astaxanthin was administered everyday at three doses (20, 40, and 80 mg/kg). Pathological results indicated that astaxanthin significantly improved the pathological lesions of liver fibrosis. The levels of alanine aminotransferase aspartate aminotransferase and hydroxyproline were also significantly decreased by astaxanthin. The same results were confirmed in bile duct liagtion, (BDL) model. In addition, astaxanthin inhibited hepatic stellate cells (HSCs) activation and formation of extracellular matrix (ECM) by decreasing the expression of NF-κB and TGF-β1 and maintaining the balance between MMP2 and TIMP1. In addition, astaxanthin reduced energy production in HSCs by downregulating the level of autophagy. These results were simultaneously confirmed in vivo and in vitro. In conclusion, our study showed that 80 mg/kg astaxanthin had a significant protective effect on liver fibrosis by suppressing multiple profibrogenic factors.

  18. Protective Effect of Astaxanthin on Liver Fibrosis through Modulation of TGF-β1 Expression and Autophagy

    Directory of Open Access Journals (Sweden)

    Miao Shen

    2014-01-01

    Full Text Available Liver fibrosis is a common pathway leading to cirrhosis and a worldwide clinical issue. Astaxanthin is a red carotenoid pigment with antioxidant, anticancer, and anti-inflammatory properties. The aim of this study was to investigate the effect of astaxanthin on liver fibrosis and its potential protective mechanisms. Liver fibrosis was induced in a mouse model using CCL4 (intraperitoneal injection, three times a week for 8 weeks, and astaxanthin was administered everyday at three doses (20, 40, and 80 mg/kg. Pathological results indicated that astaxanthin significantly improved the pathological lesions of liver fibrosis. The levels of alanine aminotransferase aspartate aminotransferase and hydroxyproline were also significantly decreased by astaxanthin. The same results were confirmed in bile duct liagtion, (BDL model. In addition, astaxanthin inhibited hepatic stellate cells (HSCs activation and formation of extracellular matrix (ECM by decreasing the expression of NF-κB and TGF-β1 and maintaining the balance between MMP2 and TIMP1. In addition, astaxanthin reduced energy production in HSCs by downregulating the level of autophagy. These results were simultaneously confirmed in vivo and in vitro. In conclusion, our study showed that 80 mg/kg astaxanthin had a significant protective effect on liver fibrosis by suppressing multiple profibrogenic factors.

  19. Chiral atomically thin films

    Science.gov (United States)

    Kim, Cheol-Joo; Sánchez-Castillo, A.; Ziegler, Zack; Ogawa, Yui; Noguez, Cecilia; Park, Jiwoong

    2016-06-01

    Chiral materials possess left- and right-handed counterparts linked by mirror symmetry. These materials are useful for advanced applications in polarization optics, stereochemistry and spintronics. In particular, the realization of spatially uniform chiral films with atomic-scale control of their handedness could provide a powerful means for developing nanodevices with novel chiral properties. However, previous approaches based on natural or grown films, or arrays of fabricated building blocks, could not offer a direct means to program intrinsic chiral properties of the film on the atomic scale. Here, we report a chiral stacking approach, where two-dimensional materials are positioned layer-by-layer with precise control of the interlayer rotation (θ) and polarity, resulting in tunable chiral properties of the final stack. Using this method, we produce left- and right-handed bilayer graphene, that is, a two-atom-thick chiral film. The film displays one of the highest intrinsic ellipticity values (6.5 deg μm-1) ever reported, and a remarkably strong circular dichroism (CD) with the peak energy and sign tuned by θ and polarity. We show that these chiral properties originate from the large in-plane magnetic moment associated with the interlayer optical transition. Furthermore, we show that we can program the chiral properties of atomically thin films layer-by-layer by producing three-layer graphene films with structurally controlled CD spectra.

  20. Chiral Shock Waves

    CERN Document Server

    Sen, Srimoyee

    2016-01-01

    We study shock waves in relativistic chiral matter. We argue that the conventional Rankine- Hugoinot relations are modified due to the presence of chiral transport phenomena. We show that the entropy discontinuity in a weak shock wave is linearly proportional to the pressure discontinuity when the effect of chiral transport becomes sufficiently large. We also show that rarefaction shock waves, which do not exist in usual nonchiral fluids, can appear in chiral matter. These features are exemplified by shock propagation in dense neutrino matter in the hydrodynamic regime.

  1. Anomalous chiral superfluidity

    Energy Technology Data Exchange (ETDEWEB)

    Lublinsky, Michael, E-mail: lublinsky@phys.uconn.ed [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794 (United States); Physics Department, Ben-Gurion University, Beer Sheva 84105 (Israel); Zahed, Ismail [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794 (United States)

    2010-02-08

    We discuss both the anomalous Cartan currents and the energy-momentum tensor in a left chiral theory with flavor anomalies as an effective theory for flavored chiral phonons in a chiral superfluid with the gauged Wess-Zumino-Witten term. In the mean-field (leading tadpole) approximation the anomalous Cartan currents and the energy-momentum tensor take the form of constitutive currents in the chiral superfluid state. The pertinence of higher order corrections and the Adler-Bardeen theorem is briefly noted.

  2. Doped Chiral Polymer Metamaterials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Doped Chiral Polymer Metamaterials (DCPM) with tunable resonance frequencies have been developed by adding plasmonic inclusions into chiral polymers with variable...

  3. Suppressive effect of astaxanthin isolated from the Xanthophyllomyces dendrorhous mutant on ethanol-induced gastric mucosal injury in rats.

    Science.gov (United States)

    Kim, Jeong-Hwan; Choi, Seok-Keun; Choi, Sang-Yun; Kim, Han-Kyeom; Chang, Hyo-Ihl

    2005-07-01

    Ethanol has been found to induce ulcerative gastric lesion in humans. The present study investigated the in vivo protective effect of astaxanthin isolated from the Xanthophyllomyces dendrorhous mutant against ethanol-induced gastric mucosal injury in rats. The rats were treated with 80% ethanol for 3 d after pretreatment with two doses of astaxanthin (5 and 25 mg/kg of body weight respectively) for 3 d, while the control rats received only 80% ethanol for 3 d. The oral administration of astaxanthin (5 and 25 mg/kg of body weight) showed significant protection against ethanol-induced gastric lesion and inhibited elevation of the lipid peroxide level in gastric mucosa. In addition, pretreatment with astaxanthin resulted in a significant increase in the activities of radical scavenging enzymes such as superoxide dismutase, catalase, and glutathione peroxidase. A histologic examination clearly indicated that the acute gastric mucosal lesion induced by ethanol nearly disappeared after pretreatment with astaxanthin.

  4. Production of the Marine Carotenoid Astaxanthin by Metabolically Engineered Corynebacterium glutamicum.

    Science.gov (United States)

    Henke, Nadja A; Heider, Sabine A E; Peters-Wendisch, Petra; Wendisch, Volker F

    2016-06-30

    Astaxanthin, a red C40 carotenoid, is one of the most abundant marine carotenoids. It is currently used as a food and feed additive in a hundred-ton scale and is furthermore an attractive component for pharmaceutical and cosmetic applications with antioxidant activities. Corynebacterium glutamicum, which naturally synthesizes the yellow C50 carotenoid decaprenoxanthin, is an industrially relevant microorganism used in the million-ton amino acid production. In this work, engineering of a genome-reduced C. glutamicum with optimized precursor supply for astaxanthin production is described. This involved expression of heterologous genes encoding for lycopene cyclase CrtY, β-carotene ketolase CrtW, and hydroxylase CrtZ. For balanced expression of crtW and crtZ their translation initiation rates were varied in a systematic approach using different ribosome binding sites, spacing, and translational start codons. Furthermore, β-carotene ketolases and hydroxylases from different marine bacteria were tested with regard to efficient astaxanthin production in C. glutamicum. In shaking flasks, the C. glutamicum strains developed here overproduced astaxanthin with volumetric productivities up to 0.4 mg·L(-1)·h(-1) which are competitive with current algae-based production. Since C. glutamicum can grow to high cell densities of up to 100 g cell dry weight (CDW)·L(-1), the recombinant strains developed here are a starting point for astaxanthin production by C. glutamicum.

  5. Production of the Marine Carotenoid Astaxanthin by Metabolically Engineered Corynebacterium glutamicum

    Directory of Open Access Journals (Sweden)

    Nadja A. Henke

    2016-06-01

    Full Text Available Astaxanthin, a red C40 carotenoid, is one of the most abundant marine carotenoids. It is currently used as a food and feed additive in a hundred-ton scale and is furthermore an attractive component for pharmaceutical and cosmetic applications with antioxidant activities. Corynebacterium glutamicum, which naturally synthesizes the yellow C50 carotenoid decaprenoxanthin, is an industrially relevant microorganism used in the million-ton amino acid production. In this work, engineering of a genome-reduced C. glutamicum with optimized precursor supply for astaxanthin production is described. This involved expression of heterologous genes encoding for lycopene cyclase CrtY, β-carotene ketolase CrtW, and hydroxylase CrtZ. For balanced expression of crtW and crtZ their translation initiation rates were varied in a systematic approach using different ribosome binding sites, spacing, and translational start codons. Furthermore, β-carotene ketolases and hydroxylases from different marine bacteria were tested with regard to efficient astaxanthin production in C. glutamicum. In shaking flasks, the C. glutamicum strains developed here overproduced astaxanthin with volumetric productivities up to 0.4 mg·L−1·h−1 which are competitive with current algae-based production. Since C. glutamicum can grow to high cell densities of up to 100 g cell dry weight (CDW·L−1, the recombinant strains developed here are a starting point for astaxanthin production by C. glutamicum.

  6. Four Different Methods Comparison for Extraction of Astaxanthin from Green Alga Haematococcus pluvialis

    Directory of Open Access Journals (Sweden)

    Shengzhao Dong

    2014-01-01

    Full Text Available Haematococcus pluvialis is one of the potent organisms for production of astaxanthin. Up to now, no efficient method has been achieved due to its thick cell wall hindering solvent extraction of astaxanthin. In this study, four different methods, hydrochloric acid pretreatment followed by acetone extraction (HCl-ACE, hexane/isopropanol (6 : 4, v/v mixture solvents extraction (HEX-IPA, methanol extraction followed by acetone extraction (MET-ACE, 2-step extraction, and soy-oil extraction, were intensively evaluated for extraction of astaxanthin from H. pluvialis. Results showed that HCl-ACE method could obtain the highest oil yield (33.3±1.1% and astaxanthin content (19.8±1.1%. Quantitative NMR analysis provided the fatty acid chain profiles of total lipid extracts. In all cases, oleyl chains were predominant, and high amounts of polyunsaturated fatty acid chains were observed and the major fatty acid components were oleic acid (13–35%, linoleic acid (37–43%, linolenic acid (20–31%, and total saturated acid (17–28%. DPPH radical scavenging activity of extract obtained by HCl-ACE was 73.2±1.0%, which is the highest amongst the four methods. The reducing power of extract obtained by four extraction methods was also examined. It was concluded that the proposed extraction method of HCl-ACE in this work allowed efficient astaxanthin extractability with high antioxidant properties.

  7. Metabolic engineering of tomato for high-yield production of astaxanthin.

    Science.gov (United States)

    Huang, Jun-Chao; Zhong, Yu-Juan; Liu, Jin; Sandmann, Gerhard; Chen, Feng

    2013-05-01

    Dietary carotenoids have been shown to be beneficial to health by decreasing the risk of many diseases. Attempts to enhance carotenoids in food crops have been successful although higher plants appear to resist big changes of carotenoid biosynthesis by metabolic engineering. Here we report the generation of a more nutritious tomato by modifying the intrinsic carotenes to astaxanthin, a high-value ketocarotenoid rarely found in plants. This was achieved by co-expression of the algal β-carotene ketolase from Chlamydomonas reinhardtii and β-carotene hydroxylase from Haematococcus pluvialis, a unique pair of enzymes identified to co-operate perfectly in converting β-carotene to astaxanthin by functional complementation in Escherichia coli. Expression of the two enzymes in tomato up-regulated most intrinsic carotenogenic genes, and efficiently directed carbon flux into carotenoids, leading to massive accumulations of mostly free astaxanthin in leaves (3.12mg/g) but esterified astaxanthin in fruits (16.1mg/g) and a 16-fold increase of total carotenoid capacity therein without affecting the plant normal growth and development. This study opened up the possibility of employing crop plants as green factories for economical production of astaxanthin.

  8. Safety assessment of [3S, 3'S]-astaxanthin--Subchronic toxicity study in rats.

    Science.gov (United States)

    Buesen, R; Schulte, S; Strauss, V; Treumann, S; Becker, M; Gröters, S; Carvalho, S; van Ravenzwaay, B

    2015-07-01

    Astaxanthin, a naturally occurring xanthophyll, is commercially used as a coloring agent in salmon feed, but also marketed as a dietary supplement. The objective of this study was to investigate the subchronic toxicity of synthetic [3S, 3'S]-Astaxanthin in rats. A powder formulation containing approximately 20% [3S, 3'S]-Astaxanthin was administered via the diet to groups of 10 male and 10 female Wistar rats at concentrations of 5000, 15,000 and 50,000 ppm for a period of 13 weeks. A formulation of comparable composition but without [3S, 3'S]-Astaxanthin served as a placebo control. There were no effects observed on survival, clinical examinations, clinical pathology, estrous cycle as well as on sperm parameters. At terminal necropsy, a macroscopically visible brown-blue discoloration of the gastrointestinal contents was noted which was considered to be secondary to the violet-brown color of the test material. No other significant or dose-related abnormalities were found in the tissues collected at termination. Our observations support that ingestion of [3S, 3'S]-Astaxanthin of up to 700-920 mg/kg bw/day in rats in a gelatin/carbohydrate formulation is without adverse effects.

  9. Extraction of Astaxanthin from Euphausia pacific Using Subcritical 1,1,1,2-tetrafluoroethane

    Institute of Scientific and Technical Information of China (English)

    HAN Yuqian; MA Qinchuan; WANG Lan; XUE Changhu

    2012-01-01

    Euphausia pacific is an important source of natural astaxanthin.Studies were carried out to assess the extractability of astaxanthin from E.pacific using subcritical 1,1,1,2-tetrafluoroethane (R134a).To examine the effects of multiple process variables on the extraction yield,astaxanthin was extracted under various conditions of pressure (30-150 bar),temperature (303-343 K),time (10-50min),flow rate (2-10gmin-1),moisture content (5.5%-63.61%),and particle size (0.25-0.109mm).The results showed that the extraction yield increased with temperature,pressure,time and flow rate,but decreased with moisture content and particle size.A maximum yield of 87.74% was obtained under conditions of 100bar,333 K,and 30min with a flow rate of 6g min-1 and a moisture content of 5.5%.The substantial astaxanthin yield obtained under low-pressure conditions demonstrates that subcritical R134a is a good alternative to CO2 for extraction of astaxanthin from E.pacific.

  10. Extraction of astaxanthin from Euphausia pacific using subcritical 1, 1, 1, 2-tetrafluoroethane

    Science.gov (United States)

    Han, Yuqian; Ma, Qinchuan; Wang, Lan; Xue, Changhu

    2012-12-01

    Euphausia pacific is an important source of natural astaxanthin. Studies were carried out to assess the extractability of astaxanthin from E. pacific using subcritical 1, 1, 1, 2-tetrafluoroethane (R134a). To examine the effects of multiple process variables on the extraction yield, astaxanthin was extracted under various conditions of pressure (30-150 bar), temperature (303-343 K), time (10-50 min), flow rate (2-10 g min-1), moisture content (5.5%-63.61%), and particle size (0.25-0.109 mm). The results showed that the extraction yield increased with temperature, pressure, time and flow rate, but decreased with moisture content and particle size. A maximum yield of 87.74% was obtained under conditions of 100 bar, 333 K, and 30 min with a flow rate of 6 g min-1 and a moisture content of 5.5%. The substantial astaxanthin yield obtained under low-pressure conditions demonstrates that subcritical R134a is a good alternative to CO2 for extraction of astaxanthin from E. pacific.

  11. Transcriptome Analysis in Haematococcus pluvialis: Astaxanthin Induction by Salicylic Acid (SA) and Jasmonic Acid (JA).

    Science.gov (United States)

    Gao, Zhengquan; Li, Yan; Wu, Guanxun; Li, Guoqiang; Sun, Haifeng; Deng, Suzhen; Shen, Yicheng; Chen, Guoqiang; Zhang, Ruihao; Meng, Chunxiao; Zhang, Xiaowen

    2015-01-01

    Haematococcus pluvialis is an astaxanthin-rich microalga that can increase its astaxanthin production by salicylic acid (SA) or jasmonic acid (JA) induction. The genetic transcriptome details of astaxanthin biosynthesis were analyzed by exposing the algal cells to 25 mg/L of SA and JA for 1, 6 and 24 hours, plus to the control (no stress). Based on the RNA-seq analysis, 56,077 unigenes (51.7%) were identified with functions in response to the hormone stress. The top five identified subcategories were cell, cellular process, intracellular, catalytic activity and cytoplasm, which possessed 5600 (~9.99%), 5302 (~9.45%), 5242 (~9.35%), 4407 (~7.86%) and 4195 (~7.48%) unigenes, respectively. Furthermore, 59 unigenes were identified and assigned to 26 putative transcription factors (TFs), including 12 plant-specific TFs. They were likely associated with astaxanthin biosynthesis in Haematococcus upon SA and JA stress. In comparison, the up-regulation of differential expressed genes occurred much earlier, with higher transcript levels in the JA treatment (about 6 h later) than in the SA treatment (beyond 24 h). These results provide valuable information for directing metabolic engineering efforts to improve astaxanthin biosynthesis in H. pluvialis.

  12. Stimulation of astaxanthin formation in the yeast Xanthophyllomyces dendrorhous by the fungus Epicoccum nigrum.

    Science.gov (United States)

    Echavarri-Erasun, Carlos; Johnson, Eric A

    2004-01-01

    A fungal contaminant on an agar plate containing colonies of Xanthophyllomyces dendrorhous markedly increased carotenoid production by yeast colonies near to the fungal growth. Spent-culture filtrate from growth of the fungus in yeast-malt medium also stimulated carotenoid production by X. dendrorhous. Four X. dendrorhous strains including the wild-type UCD 67-385 (ATCC 24230), AF-1 (albino mutant, ATCC 96816), Yan-1 (beta-carotene mutant, ATCC 96815) and CAX (astaxanthin overproducer mutant) exposed to fungal concentrate extract enhanced astaxanthin up to approximately 40% per unit dry cell weight in the wild-type strain and in CAX. Interestingly, the fungal extract restored astaxanthin biosynthesis in non-astaxanthin-producing mutants previously isolated in our laboratory, including the albino and the beta-carotene mutant. The fungus was identified as Epicoccum nigrum by morphology of sporulating cultures, and the identity confirmed by genetic characterization including rDNA sequencing analysis of the large-subunit (LSU), the internal transcribed spacer, and the D1/D2 region of the LSU. These E. nigrum rDNA sequences were deposited in GenBank under accesssion numbers AF338443, AY093413 and AY093414. Systematic rDNA homology alignments were performed to identify fungi related to E. nigrum. Stimulation of carotenogenesis by E. nigrum and potentially other fungi could provide a novel method to enhance astaxanthin formation in industrial fermentations of X. dendrorhous and Phaffia rhodozyma.

  13. Astaxanthin Normalizes Epigenetic Modifications of Bovine Somatic Cell Cloned Embryos and Decreases the Generation of Lipid Peroxidation.

    Science.gov (United States)

    Li, R; Wu, H; Zhuo, W W; Mao, Q F; Lan, H; Zhang, Y; Hua, S

    2015-10-01

    Astaxanthin is an extremely common antioxidant scavenging reactive oxygen species (ROS) and blocking lipid peroxidation. This study was conducted to investigate the effects of astaxanthin supplementation on oocyte maturation, and development of bovine somatic cell nuclear transfer (SCNT) embryos. Cumulus-oocyte complexes were cultured in maturation medium with astaxanthin (0, 0.5, 1.0, or 1.5 mg/l), respectively. We found that 0.5 mg/l astaxanthin supplementation significantly increased the proportion of oocyte maturation. Oocytes cultured in 0.5 mg/l astaxanthin supplementation were used to construct SCNT embryos and further cultured with 0, 0.5, 1.0 or 1.5 mg/l astaxanthin. The results showed that the supplementation of 0.5 mg/l astaxanthin significantly improved the proportions of cleavage and blastulation, as well as the total cell number in blastocysts compared with the control group, yet this influence was not concentration dependent. Chromosomal analyses revealed that more blastomeres showed a normal chromosomal complement in 0.5 mg/l astaxanthin treatment group, which was similar to that in IVF embryos. The methylation levels located on the exon 1 of the imprinted gene H19 and IGF2, pluripotent gene OCT4 were normalized, and global DNA methylation, H3K9 and H4K12 acetylation were also improved significantly, which was comparable to that in vitro fertilization (IVF) embryos. Moreover, we also found that astaxanthin supplementation significantly decreased the level of lipid peroxidation. Our findings showed that the supplementation of 0.5 mg/l astaxanthin to oocyte maturation medium and embryo culture medium improved oocyte maturation, SCNT embryo development, increased chromosomal stability and normalized the epigenetic modifications, as well as inhibited overproduction of lipid peroxidation.

  14. Spectral identification of fullerene C82 isomers

    Science.gov (United States)

    Gao, Bin; Liu, Lei; Wang, ChunRu; Wu, ZiYu; Luo, Yi

    2007-10-01

    Ultraviolet photoelectron spectra (UPS) of C82 isomers have been calculated using hybrid density functional theory in combination with the Gelius model [Proceedings of the International Conference on Electron spectroscopy, edited by D. A. Shirley (North-Holland, Amsterdam, 1972), p. 311; J. Electron Spectrosc. Relat. Phenom. 5, 985 (1974)]. The calculated UPS spectra are found to be isomer dependent and in good agreement with the experimental counterparts. Near-edge x-ray absorption fine structure (NEXAFS), x-ray photoelectron spectroscopy (XPS), x-ray emission spectroscopy, and the resonant inelastic x-ray scattering (RIXS) spectra of three important isomers [3(C2), 6(Cs), and 9(C2v)] have also been simulated. Strong isomer dependence has also been found for NEXAFS, XPS, and RIXS spectra.

  15. Comparative analysis of astaxanthin and its esters in the mutant E1 of Haematococcus pluvialis and other green algae by HPLC with a C30 column

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A gradient reversed-phase high-performance liquid chromatography (HPLC) method using a C30 col-umn was developed for the simultaneous determination of astaxanthin, astaxanthin monoesters and astaxanthin diesters in the green algae Chlorococcum sp., Chlorella zofingiensis, Haematococcus plu-vialis and the mutant E1, which was obtained from the mutagenesis of H. pluvialis by exposure to UV-irradiation and ethyl methanesulphonate (EMS) with subsequent screening using nicotine. The re-sults showed that the contents of total astaxanthins including free astaxanthin and astaxanthin esters ranged from 1.4 to 30.9 mg/g dry biomass in these green algae. The lower total astaxanthin levels (< 2 mg/g dry biomass) were detected in the green algae Chlorococcum sp. and C. zofingiensis. The higher total astaxanthin levels (>16 mg/g dry biomass) were found in the green alga H. pluvialis and its mutant E1. It is notable that the mutant E1 is found to have considerably higher amounts of total astaxanthin (30.9 mg/g) as compared to the wild strain of H. pluvialis (16.1 mg/g). This indicates that UV-irradiation and EMS compound mutagenesis with subsequent screening using nicotine is an effective method for breeding of a high-producing astaxanthin strain of H. pluvialis. In addition, the green alga C. zofingien-sis had a remarkably higher percentage of astaxanthin diesters (76.3% of total astaxanthins) and a re-markably lower percentage of astaxanthin monoesters (18.0% of total astaxanthins) in comparison with H. pluvialis (35.5% for diesters and 60.9% for monoesters), the mutant E1 (49.1% and 48.1%) and Chlorococcum sp. (18.0% and 58.6%).

  16. Comparative analysis of astaxanthin and its esters in the mutant E1 of Haematococcus pluvialis and other green algae by HPLC with a C30 column

    Institute of Scientific and Technical Information of China (English)

    PENG Juan; XIANG WenZhou; TANG QuanMing; SUN Ni; CHEN Feng; YUAN JianPing

    2008-01-01

    A gradient reversed-phase high-performance liquid chromatography (HPLC) method using a 030 column was developed for the simultaneous determination of astaxanthin, astaxanthin monoesters and astaxanthin diesters in the green algae Chlorococcum sp., Chlorella zofingiensis, Haematococcus pluvialis and the mutant E1, which was obtained from the mutagenesis of H. pluvialis by exposure to UV-irradiation and ethyl methanesulphonate (EMS) with subsequent screening using nicotine. The results showed that the contents of total astaxanthins including free astaxanthin and astaxanthin esters ranged from 1.4 to 30.9 mg/g dry biomass in these green algae. The lower total astaxanthin levels (< 2 mg/g dry biomass) were detected in the green algae Chlorococcum sp. and C. zofingiensis. The higher total astaxanthin levels (>16 mg/g dry biomass) were found in the green alga H. pluvialis and its mutant El. It is notable that the mutant E1 is found to have considerably higher amounts of total astaxanthin (30.9 mg/g) as compared to the wild strain of H. pluvialis (16.1 mg/g). This indicates that UV-irradiation and EMS compound mutagenesis with subsequent screening using nicotine is an effective method for breeding of a high-producing astaxanthin strain of H. pluvialis. In addition, the green alga C. zofingiensis had a remarkably higher percentage of astaxanthin diesters (76.3% of total astaxanthins) and a remarkably lower percentage of astaxanthin monoesters (18.0% of total astaxanthins) in comparison with H. pluvialis (35.5% for diesters and 60,9% for monoesters), the mutant E1 (49.1% and 48.1%) and Chlorococcum sp. (18.0% and 58.6%).

  17. Optimization of the IPP precursor supply for the production of lycopene, decaprenoxanthin and astaxanthin by Corynebacterium glutamicum

    Directory of Open Access Journals (Sweden)

    Sabine A.E. Heider

    2014-08-01

    Full Text Available The biotechnologically relevant bacterium C. glutamicum, currently used for the million ton-scale production of amino acids for the food and feed industries, is pigmented due to synthesis of the rare cyclic C50 carotenoid decaprenoxanthin and its glucosides. The precursors of carotenoid biosynthesis, isopenthenyl pyrophosphate (IPP and its isomer dimethylallyl pyrophosphate (DMAPP, are synthesized in this organism via the methylerythritol phosphate (MEP or non-mevalonate pathway. Terminal pathway engineering in recombinant C. glutamicum permitted the production of various nonnative C50 and C40 carotenoids. Here, the role of engineering isoprenoid precursor supply for lycopene production by C. glutamicum was characterized. Overexpression of dxs encoding the enzyme that catalyzes the first committed step of the MEP-pathway by chromosomal promoter exchange in a prophage-cured, genome-reduced C. glutamicum strain improved lycopene formation. Similarly, an increased IPP supply was achieved by chromosomal integration of two artificial operons comprising MEP pathway genes under the control of a constitutive promoter. Combined overexpression of dxs and the other six MEP pathways genes in C. glutamicum strain LYC3-MEP was not synergistic with respect to improving lycopene accumulation. Based on C. glutamicum strain LYC3-MEP astaxanthin could be produced in the mg per g cell dry weight range when the endogenous genes crtE, crtB and crtI for conversion of geranylgeranyl pyrophosphate to lycopene were coexpressed with the genes for lycopene cyclase and β-carotene hydroxylase from Pantoea ananatis and carotene C(4 oxygenase from Brevundimonas aurantiaca.

  18. Applications of chiral symmetry

    CERN Document Server

    Pisarski, R D

    1995-01-01

    I discuss several topics in the applications of chiral symmetry at nonzero temperature, including: where the rho goes, disoriented chiral condensates, and the phase diagram for QCD with 2+1 flavors. (Based upon talks presented at the "Workshop on Finite Temperature QCD", Wuhan, P.R.C., April, 1994.)

  19. Effects of Astaxanthin from Litopenaeus Vannamei on Carrageenan-Induced Edema and Pain Behavior in Mice

    Directory of Open Access Journals (Sweden)

    Zulkiflee Kuedo

    2016-03-01

    Full Text Available Carrageenan produces both inflammation and pain when injected in mouse paws via enhancement of reactive oxygen species formation. We have investigated an effect of astaxanthin extracted from Litopenaeus vannamei in carrageenan-induced mice paw edema and pain. The current study demonstrates interesting effects from astaxanthin treatment in mice: an inhibition of paw edema induced in hind paw, an increase in mechanical paw withdrawal threshold and thermal paw withdrawal latency, and a reduction in the amount of myeloperoxidase enzyme and lipid peroxidation products in the paw. Furthermore the effect was comparable to indomethacin, a standard treatment for inflammation symptoms. Due to adverse effects of indomethacin on cardiovascular and gastrointestinal systems, our study suggests promising prospect of astaxanthin extract as an anti-inflammatory alternative against carrageenan-induced paw edema and pain behavior.

  20. Purification of Astaxanthin from Laminariajaponica by Ionic Liquid-based Monolithic Cartridge

    Institute of Scientific and Technical Information of China (English)

    YOON Chang-hwan; ZHU Tao; ROW Kyung-ho

    2012-01-01

    An effective and accurate method was developed for the extraction of astaxanthin from Laminariajaponica with subsequent separation by ionic liquid-based monolithic cartridge.The optimized extraction conditions including extraction solvent(ethanol),extraction time(90 min) and ultrasonic power(75 W) were obtained by systematical investigation.Chromatographic analysis was performed on a C18 column with ultraviolet(UV) detection at 476nm,and a solution consisting of methanol/acetonitrile/H20/dichloromethane(83:6:6:5,volume ratio) was used as the mobile phase at a flow rate of 0.7 mL/min.After ionic liquid-based monolithic solid phase extraction,17.82 μg/g astaxanthin was obtained from Laminariajaponica.This ionic liquid-based monolithic cartridge exhibits high affinity and selectivity for astaxanthin,and it can be potentially used as the stationary phase of high performance liquid chromatography( HPLC).

  1. Astaxanthin protecting membrane integrity against photosensitized oxidation through synergism with other carotenoids

    DEFF Research Database (Denmark)

    Du, Hui-Hui; Liang, Ran; Han, Rui-Min

    2015-01-01

    using optical microscopy and digital image heterogeneity analysis. The lowest initial rate of GUV budding after the lag phase was seen for GUVs with astaxanthin as the least reducing carotenoid, while the lowest final level of entropy appeared for those with lycopene or β-carotene as a more reducing...... carotenoid. The combination of astaxanthin and lycopene gave optimal protection against budding with respect to both a longer lag phase and lower final level of entropy by combining good electron acceptance and good electron donation. Quenching of singlet oxygen by carotenoids close to chlorophyll...... a in the membrane interior in parallel with scavenging of superoxide radicals by astaxanthin anchored in the surface may explain the synergism between carotenoids involving both type I and type II photosensitization by chlorophyll a....

  2. Isolation and optimization of production of Astaxanthin from Antarctic yeast Rhodotorula sp.NJ298

    Institute of Scientific and Technical Information of China (English)

    Liu Junling; Miao Jinlai; Sun Xiuqin; Wang Quanfu; Li Guangyou

    2007-01-01

    Rhodotorula sp. NJ298 which could produce carotenoids was isolated from Antarctic sea ice. The major carotenoid was identified as astaxanthin by Liquid Chromatography/Mass Spectrometry(LC/MS), and its content accounted for 87.62% of total carotenoids (1,786 μg/g). High Performance Liquid Chromatogrephy(HPLC)analysis showed that the purity of the astaxanthin reached about 96.16% through a simple purification. Maximum astaxanthin production(1,908/μg/g)was obtained when the yeast was grown at 10℃ in seawater medium containing 5g/L sodium acetate, 5g/L peptone, 0.5g/L NaCl, 0.01g/L KH2P04;0.01g/L MgS04·7H2O and 0.001 g/L FeS04·7H20 at pH 7.5.

  3. Recovery of astaxanthin from discharged wastewater during the production of chitin

    Science.gov (United States)

    Chen, Xiaolin; Yang, Shengfeng; Xing, Ronge; Yu, Huahua; Liu, Song; Li, Pengcheng

    2012-06-01

    In this paper, studies were carried out to extract astaxanthin from discharged wastewater during the production of chitin and to reveal the scavenging effect of the obtained pigment on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical. Different ratios of dichloromethane/methanol (V/V) were used to extract astaxanthin. When the ratio of dichloromethane/methanol was 2:8 and the ratio between the mixed organic solvent (dichloromethane/methanol, 2:8, V/V) and wastewater was 1:1, the highest yield of pigment was obtained (8.4 mg/50 mL). The concentration of free astaxanthin in the obtained pigment analyzed by HPLC was 30.02%. The obtained pigment possessed strong scavenging ability on DPPH radical and IC50 was 0.84mg/ml.

  4. Effects of Astaxanthin from Litopenaeus Vannamei on Carrageenan-Induced Edema and Pain Behavior in Mice.

    Science.gov (United States)

    Kuedo, Zulkiflee; Sangsuriyawong, Anantita; Klaypradit, Wanwimol; Tipmanee, Varomyalin; Chonpathompikunlert, Pennapa

    2016-03-19

    Carrageenan produces both inflammation and pain when injected in mouse paws via enhancement of reactive oxygen species formation. We have investigated an effect of astaxanthin extracted from Litopenaeus vannamei in carrageenan-induced mice paw edema and pain. The current study demonstrates interesting effects from astaxanthin treatment in mice: an inhibition of paw edema induced in hind paw, an increase in mechanical paw withdrawal threshold and thermal paw withdrawal latency, and a reduction in the amount of myeloperoxidase enzyme and lipid peroxidation products in the paw. Furthermore the effect was comparable to indomethacin, a standard treatment for inflammation symptoms. Due to adverse effects of indomethacin on cardiovascular and gastrointestinal systems, our study suggests promising prospect of astaxanthin extract as an anti-inflammatory alternative against carrageenan-induced paw edema and pain behavior.

  5. Cytotoxic Induction and Photoacoustic Imaging of Breast Cancer Cells Using Astaxanthin-Reduced Gold Nanoparticles

    Directory of Open Access Journals (Sweden)

    Subramaniyan Bharathiraja

    2016-04-01

    Full Text Available Astaxanthin, a kind of photosynthetic pigment, was employed for gold nanoparticle formation. Nanoparticles were characterized using Ulteraviolet-Visible (UV-Vis spectroscopy, transmission electron microscopy, and X-ray diffraction, and the possible presence of astaxanthin functional groups were analyzed by Fourier transform infrared spectroscopy (FTIR. The cytotoxic effect of synthesized nanoparticles was evaluated against MDA-MB-231 (human breast cancer cells using a tetrazolium-based assay, and synthesized nanoparticles exhibited dose-dependent toxicity. The morphology upon cell death was differentiated through fluorescent microscopy using different stains that predicted apoptosis. The synthesized nanoparticles were applied in ultrasound-coupled photoacoustic imaging to obtain good images of treated cells. Astaxanthin-reduced gold nanoparticle has the potential to act as a promising agent in the field of photo-based diagnosis and therapy.

  6. Cell-wall disruption and lipid/astaxanthin extraction from microalgae: Chlorella and Haematococcus.

    Science.gov (United States)

    Kim, Dong-Yeon; Vijayan, Durairaj; Praveenkumar, Ramasamy; Han, Jong-In; Lee, Kyubock; Park, Ji-Yeon; Chang, Won-Seok; Lee, Jin-Suk; Oh, You-Kwan

    2016-01-01

    Recently, biofuels and nutraceuticals produced from microalgae have emerged as major interests, resulting in intensive research of the microalgal biorefinery process. In this paper, recent developments in cell-wall disruption and extraction methods are reviewed, focusing on lipid and astaxanthin production from the biotechnologically important microalgae Chlorella and Haematococcus, respectively. As a common, critical bottleneck for recovery of intracellular components such as lipid and astaxanthin from these microalgae, the composition and structure of rigid, thick cell-walls were analyzed. Various chemical, physical, physico-chemical, and biological methods applied for cell-wall breakage and lipid/astaxanthin extraction from Chlorella and Haematococcus are discussed in detail and compared based on efficiency, energy consumption, type and dosage of solvent, biomass concentration and status (wet/dried), toxicity, scalability, and synergistic combinations. This report could serve as a useful guide to the implementation of practical downstream processes for recovery of valuable products from microalgae including Chlorella and Haematococcus.

  7. Efficiency of selected mutagens in generating Xanthophyllomyces dendrorhous strains hyperproducing astaxanthin.

    Science.gov (United States)

    Stachowiak, Barbara

    2013-01-01

    Astaxanthin is a xanthophill pigment with commercial application in the aquaculture, pharmaceutical, food and cosmetic industries. The red yeast Xanthophyllomyces dendrorhous is one of the most promising microorganisms for its industrial production. However, astaxanthin content in wild yeast strains is low. Pigment production by X. dendrorhous can be improved by mutagenesis. The aim of the study was to assess the efficiency of four mutagens: UV radiation, benomyl, ethyl methanesulfonate and ethidium bromide in generating asthaxanthin-hyperproducing strains of the yeast Xanthophyllomyces dendrorhous DSM 5626. Mutations with benomyl, ethidium bromide and UV radiation generated a group of hyperpigmented mutants exhibiting increases up to 100% in astaxanthin content. Ethyl methanesulfonate turned out to be useless in this respect.

  8. An efficient method for the extraction of astaxanthin from the red yeast Xanthophyllomyces dendrorhous.

    Science.gov (United States)

    Choi, Seok-Keun; Kim, Jeong-Hwan; Park, Young-Sam; Kim, Young-Jin; Chang, Hyo-Ihl

    2007-05-01

    This study investigated an efficient method for the extraction of astaxanthin from the red yeast Xanthophyllomyces dendrorhous. The extraction process comprised three steps: (1) cultivating the yeast; (2) treating the yeast culture suspension with microwaves to destroy the cell walls and microbodies; and (3) drying the yeast and extracting the astaxanthin pigment using ethanol, methanol, acetone, or a mixture of the three as the extraction solvent. Ultimately, various treatment tests were performed to determine the conditions for optimal pigment extraction, and the total carotenoid and astaxanthin contents were quantified. A frequency of 2,450 MHz, an output of 500 watts, and irradiation time of 60 s were the most optimum conditions for yeast cell wall destruction. Furthermore, optimal pigment extraction occurred when using a cell density of 10 g/l at 30 C over 24 h, with a 10% volume of ethanol.

  9. Combined conventional/antioxidant "Astaxanthin" treatment for male infertility: a double blind, randomized trial

    Institute of Scientific and Technical Information of China (English)

    F. H. Comhaire; Y. El Garem; A. Mahmoud; F. Eertmans; F. Schoonjans

    2005-01-01

    Aim: To evaluate the treatment of male infertility with a strong natural antioxidant, in addition to conventional treatment.Methods: Using a double blind, randomized trial design, 30 men with infertility of ≥12 months and female partners with no demonstrable cause of infertility received conventional treatment according to the guidelines of the World Health Organization (WHO), and either a strong antioxidant Astaxanthin 16 mg/day (AstaCarox(R), AstaReal AB,Gustavsberg, Sweden) or placebo for 3 months. The effects of treatment on semen parameters, reactive oxygen species (ROS), zona-free hamster oocyte test, serum hormones including testosterone, luteinizing hormone (LH),follicle stimulating hormone (FSH) and Inhibin B, and spontaneous or intrauterine insemination (IUI)-induced pregnancies were evaluated. Results: ROS and Inhibin B decreased significantly and sperm linear velocity increased in the Astaxanthin group (n = 11), but not in the placebo group (n = 19). The results of the zona-free hamster oocyte test tended to improve in the Astaxanthin group in contrast with the placebo group, though not reaching statistical significance.The total and per cycle pregnancy rates among the placebo cases (10.5 % and 3.6 %) were lower compared with 54.5 % and 23.1% respectively in the Astaxanthin group (P = 0.028; P = 0.036). Conclusion: Although the present study suggests a positive effect of Astaxanthin on sperm parameters and fertility, the results need to be confirmed in a larger trial before recommending Astaxanthin for the complementary treatment of infertile men.

  10. Specific light uptake rates can enhance astaxanthin productivity in Haematococcus lacustris.

    Science.gov (United States)

    Lee, Ho-Sang; Kim, Z-Hun; Park, Hanwool; Lee, Choul-Gyun

    2016-05-01

    Lumostatic operation was applied for efficient astaxanthin production in autotrophic Haematococcus lacustris cultures using 0.4-L bubble column photobioreactors. The lumostatic operation in this study was performed with three different specific light uptake rates (q(e)) based on cell concentration, cell projection area, and fresh weight as one-, two- and three-dimensional characteristics values, respectively. The q(e) value from the cell concentration (q(e1D)) obtained was 13.5 × 10⁻⁸ μE cell⁻¹ s⁻¹, and the maximum astaxanthin concentration was increased to 150 % compared to that of a control with constant light intensity. The other optimum q e values by cell projection area (q(e2D)) and fresh weight (q( e3D)) were determined to be 195 μE m⁻² s⁻¹ and 10.5 μE g⁻¹ s⁻¹ for astaxanthin production, respectively. The maximum astaxanthin production from the lumostatic cultures using the parameters controlled by cell projection area (2D) and fresh weight (3D) also increased by 36 and 22% over that of the controls, respectively. When comparing the optimal q e values among the three different types, the lumostatic cultures using q(e) based on fresh weight showed the highest astaxanthin productivity (22.8 mg L⁻¹ day⁻¹), which was a higher level than previously reported. The lumostatic operations reported here demonstrated that more efficient and effective astaxanthin production was obtained by H. lacustris than providing a constant light intensity, regardless of which parameter is used to calculate the specific light uptake rate.

  11. Intermolecular chiral assemblies in R(-) and S(+) 2-butanol detected by microcalorimetry measurements.

    Science.gov (United States)

    Cogan, Uri; Shpigelman, Avi; Portnaya, Irina; Rutenberg, Abraham; Scolnik, Yosef; Shinitzky, Meir

    2012-07-01

    Supramolecular chiral assemblies of R(-) and S(+) 2-butanol, in their neat form or when dissolved in their nonchiral isomer isobutanol, were evaluated by isothermal titration calorimetry (ITC) ensuing mixing. Dilution of 0.5 M solution of R(-) 2-butanol in isobutanol into the latter liberated heat of several calories per mole, which was approximately double than that obtained in parallel dilutions of S(+) 2-butanol in isobutanol. The ITC dilution profiles indicated an estimate of about 100 isobutanol solvent molecules surrounding each of the 2-butanol enantiomers, presumably arranged in chiral configurations, with different adopted order between the isomers. Mixings of neat R and S 2-butanol were followed by endothermic ITC profiles, indicating that, in racemic 2-butanol, both the supramolecular order and the intermolecular binding energies are lower than in each of the neat chiral isomers. The diversion from symmetrical ITC patterns in these mixings indicated again a subtle difference in molecular organization between the neat enantiomers. It should be noted that the presence of impurities, α-pinene and teterhydrofuran, at a level totaling 0.5%, did not influence the ITC heat flow profiles. The findings of this study demonstrate for the first time that chiral solutes in organic solvents are expected to acquire asymmetric solvent envelopes that may be different between the enantiomers, thus broadening this phenomenon beyond the previously demonstrated cases in aqueous solutions.

  12. Geometrical approach to central molecular chirality: a chirality selection rule

    OpenAIRE

    Capozziello, S.; Lattanzi, A

    2004-01-01

    Chirality is of primary importance in many areas of chemistry and has been extensively investigated since its discovery. We introduce here the description of central chirality for tetrahedral molecules using a geometrical approach based on complex numbers. According to this representation, for a molecule having n chiral centres, it is possible to define an index of chirality. Consequently a chirality selection rule has been derived which allows the characterization of a molecule as achiral, e...

  13. Hyperspectral imaging based on diffused laser light for prediction of astaxanthin coating concentration

    DEFF Research Database (Denmark)

    Ljungqvist, Martin Georg; Nielsen, Otto Højager Attermann; Frosch, Stina;

    2014-01-01

    concentration. The results show that it is possible to predict the synthetic astaxanthin concentration in the coating well enough for quality control using both multi- and hyperspectral image analysis, while the SuperK setup performs with higher accuracy than the VideometerLab device for this particular problem....... The spectral resolution made it possible to identify the most significant spectral regions for detection of astaxanthin. The results also imply that the presented methods can be used in general for quality inspection of various coating substances using similar coating methods....

  14. Gastric inflammatory markers and interleukins in patients with functional dyspepsia treated with astaxanthin

    DEFF Research Database (Denmark)

    Andersen, L.P.; Holck, Susanne; Kupcinskas, L.;

    2007-01-01

    . There was a significant decrease in gastric inflammation in H. pylori-positive patients from both groups. There were no significant changes in the density of H. pylori or in any of the interleukins during or after treatment. There was a significant up-regulation of CD4 and down-regulation of CD8 in patients with H....... pylori treated with astaxanthin. Astaxanthin had an effect on the inflammation and on the density of H. pylori in mice in a study where the diet could be standardized without antioxidants (Bennedsen et al., 1999). These dietary conditions are impossible in studies involving humans, and may be due...

  15. Engineering of a plasmid-free Escherichia coli strain for improved in vivo biosynthesis of astaxanthin

    Directory of Open Access Journals (Sweden)

    Steuer Kristin

    2011-04-01

    Full Text Available Abstract Background The xanthophyll astaxanthin is a high-value compound with applications in the nutraceutical, cosmetic, food, and animal feed industries. Besides chemical synthesis and extraction from naturally producing organisms like Haematococcus pluvialis, heterologous biosynthesis in non-carotenogenic microorganisms like Escherichia coli, is a promising alternative for sustainable production of natural astaxanthin. Recent achievements in the metabolic engineering of E. coli strains have led to a significant increase in the productivity of carotenoids like lycopene or β-carotene by increasing the metabolic flux towards the isoprenoid precursors. For the heterologous biosynthesis of astaxanthin in E. coli, however, the conversion of β-carotene to astaxanthin is obviously the most critical step towards an efficient biosynthesis of astaxanthin. Results Here we report the construction of the first plasmid-free E. coli strain that produces astaxanthin as the sole carotenoid compound with a yield of 1.4 mg/g cdw (E. coli BW-ASTA. This engineered E. coli strain harbors xanthophyll biosynthetic genes from Pantoea ananatis and Nostoc punctiforme as individual expression cassettes on the chromosome and is based on a β-carotene-producing strain (E. coli BW-CARO recently developed in our lab. E. coli BW-CARO has an enhanced biosynthesis of the isoprenoid precursor isopentenyl diphosphate (IPP and produces β-carotene in a concentration of 6.2 mg/g cdw. The expression of crtEBIY along with the β-carotene-ketolase gene crtW148 (NpF4798 and the β-carotene-hydroxylase gene (crtZ under controlled expression conditions in E. coli BW-ASTA directed the pathway exclusively towards the desired product astaxanthin (1.4 mg/g cdw. Conclusions By using the λ-Red recombineering technique, genes encoding for the astaxanthin biosynthesis pathway were stably integrated into the chromosome of E. coli. The expression levels of chromosomal integrated recombinant

  16. Molecular model for chirality phenomena.

    Science.gov (United States)

    Latinwo, Folarin; Stillinger, Frank H; Debenedetti, Pablo G

    2016-10-21

    Chirality is a hallmark feature for molecular recognition in biology and chemical physics. We present a three-dimensional continuum model for studying chirality phenomena in condensed phases using molecular simulations. Our model system is based upon a simple four-site molecule and incorporates non-trivial kinetic behavior, including the ability to switch chirality or racemize, as well as thermodynamics arising from an energetic preference for specific chiral interactions. In particular, we introduce a chiral renormalization parameter that can locally favor either homochiral or heterochiral configurations. Using this model, we explore a range of chirality-specific phenomena, including the kinetics of chiral inversion, the mechanism of spontaneous chiral symmetry breaking in the liquid, chirally driven liquid-liquid phase separation, and chiral crystal structures.

  17. Astaxanthin ameliorates lung fibrosis in vivo and in vitro by preventing transdifferentiation, inhibiting proliferation, and promoting apoptosis of activated cells.

    Science.gov (United States)

    Wang, Meirong; Zhang, Jinjin; Song, Xiaodong; Liu, Wenbo; Zhang, Lixia; Wang, Xiuwen; Lv, Changjun

    2013-06-01

    Astaxanthin, a member of the carotenoid family, is the only known ketocarotenoid transported into the brain by transcytosis through the blood-brain barrier. However, whether astaxanthin has antifibrotic functions is unknown. In this study, we investigated the effects of astaxanthin on transforming growth factor β1-mediated and bleomycin-induced pulmonary fibrosis in vitro and in vivo. The results showed that astaxanthin significantly improved the structure of the alveoli and alleviated collagen deposition in vivo. Compared with the control group, the astaxanthin-treated groups exhibited downregulated protein expressions of α-smooth muscle actin, vimentin, hydroxyproline, and B cell lymphoma/leukemia-2 as well as upregulated protein expressions of E-cadherin and p53 in vitro and in vivo. Astaxanthin also inhibited the proliferation of activated A549 and MRC-5 cells at median inhibitory concentrations of 40 and 30 μM, respectively. In conclusion, astaxanthin could relieve the symptoms and halt the progression of pulmonary fibrosis, partly by preventing transdifferentiation, inhibiting proliferation, and promoting apoptosis of activated cells.

  18. Multiple Mechanisms of Anti-Cancer Effects Exerted by Astaxanthin

    Directory of Open Access Journals (Sweden)

    Li Zhang

    2015-07-01

    Full Text Available Astaxanthin (ATX is a xanthophyll carotenoid which has been approved by the United States Food and Drug Administration (USFDA as food colorant in animal and fish feed. It is widely found in algae and aquatic animals and has powerful anti-oxidative activity. Previous studies have revealed that ATX, with its anti-oxidative property, is beneficial as a therapeutic agent for various diseases without any side effects or toxicity. In addition, ATX also shows preclinical anti-tumor efficacy both in vivo and in vitro in various cancer models. Several researches have deciphered that ATX exerts its anti-proliferative, anti-apoptosis and anti-invasion influence via different molecules and pathways including signal transducer and activator of transcription 3 (STAT3, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB and peroxisome proliferator-activated receptor gamma (PPARγ. Hence, ATX shows great promise as chemotherapeutic agents in cancer. Here, we review the rapidly advancing field of ATX in cancer therapy as well as some molecular targets of ATX.

  19. Applications of chiral symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Pisarski, R.D.

    1995-03-01

    The author discusses several topics in the applications of chiral symmetry at nonzero temperature. First, where does the rho go? The answer: up. The restoration of chiral symmetry at a temperature T{sub {chi}} implies that the {rho} and a{sub 1} vector mesons are degenerate in mass. In a gauged linear sigma model the {rho} mass increases with temperature, m{sub {rho}}(T{sub {chi}}) > m{sub {rho}}(0). The author conjectures that at T{sub {chi}} the thermal {rho} - a{sub 1}, peak is relatively high, at about {approximately}1 GeV, with a width approximately that at zero temperature (up to standard kinematic factors). The {omega} meson also increases in mass, nearly degenerate with the {rho}, but its width grows dramatically with temperature, increasing to at least {approximately}100 MeV by T{sub {chi}}. The author also stresses how utterly remarkable the principle of vector meson dominance is, when viewed from the modern perspective of the renormalization group. Secondly, he discusses the possible appearance of disoriented chiral condensates from {open_quotes}quenched{close_quotes} heavy ion collisions. It appears difficult to obtain large domains of disoriented chiral condensates in the standard two flavor model. This leads to the last topic, which is the phase diagram for QCD with three flavors, and its proximity to the chiral critical point. QCD may be very near this chiral critical point, and one might thereby generated large domains of disoriented chiral condensates.

  20. EPR study of the astaxanthin n-octanoic acid monoester and diester radicals on silica-alumina.

    Science.gov (United States)

    Focsan, A Ligia; Bowman, Michael K; Shamshina, Julia; Krzyaniak, Matthew D; Magyar, Adam; Polyakov, Nikolay E; Kispert, Lowell D

    2012-11-08

    The radical intermediates of the n-octanoic monoester and n-octanoic diester of astaxanthin were detected by pulsed EPR measurements carried out on the UV-produced radicals on silica-alumina artificial matrix and characterized by density functional theory (DFT) calculations. Previous Mims ENDOR for astaxanthin detected the radical cation and neutral radicals formed by proton loss from the C3 (or C3') position and from the methyl groups. Deprotonation of the astaxanthin neutral radical formed at the C3 (or C3') position resulted in a radical anion. DFT calculations for astaxanthin showed that the lowest energy neutral radical forms by proton loss at the C3 (or C3') position of the terminal ring followed by proton loss at the methyl groups of the polyene chain. Contrary to astaxanthin where proton loss can occur at either end of the symmetrical radical, for the diester of astaxanthin, this loss is prevented at the cyclohexene ends and is favored for its methyl groups. The monoester of astaxanthin, however, allows formation of the neutral radical at C3' and prevents its formation at the opposite end where the ester group is attached. At the terminal ring without the ester group attached, migration of proton from hydroxyl group to carbonyl group facilitates resonance stabilization, similarly to already published results for astaxanthin. However, cw EPR shows no evidence of a monoester radical anion formed. This study suggests the different radicals of astaxanthin and its esters that would form in a preferred environment, either hydrophobic or hydrophilic, depending on their structure.

  1. Spectral signatures of chirality

    DEFF Research Database (Denmark)

    Pedersen, Jesper Goor; Mortensen, Asger

    2009-01-01

    We present a new way of measuring chirality, via the spectral shift of photonic band gaps in one-dimensional structures. We derive an explicit mapping of the problem of oblique incidence of circularly polarized light on a chiral one-dimensional photonic crystal with negligible index contrast...... to the formally equivalent problem of linearly polarized light incident on-axis on a non-chiral structure with index contrast. We derive analytical expressions for the first-order shifts of the band gaps for negligible index contrast. These are modified to give good approximations to the band gap shifts also...

  2. Chiral supergravity and anomalies

    CERN Document Server

    Mielke, E W; Macias, Alfredo; Mielke, Eckehard W.

    1999-01-01

    Similarily as in the Ashtekar approach, the translational Chern-Simons term is, as a generating function, instrumental for a chiral reformulation of simple (N=1) supergravity. After applying the algebraic Cartan relation between spin and torsion, the resulting canonical transformation induces not only decomposition of the gravitational fields into selfdual and antiselfdual modes, but also a splitting of the Rarita-Schwinger fields into their chiral parts in a natural way. In some detail, we also analyze the consequences for axial and chiral anomalies.

  3. Catalysis of Dynamical Chiral Symmetry Breaking by Chiral Chemical Potential

    CERN Document Server

    Braguta, V V

    2016-01-01

    In this paper we study the properties of media with chiral imbalance parameterized by chiral chemical potential. It is shown that depending on the strength of interaction between constituents in the media the chiral chemical potential either creates or enhances dynamical chiral symmetry breaking. Thus the chiral chemical potential plays a role of the catalyst of dynamical chiral symmetry breaking. Physically this effect results from the appearance of the Fermi surface and additional fermion states on this surface which take part in dynamical chiral symmetry breaking. An interesting conclusion which can be drawn is that at sufficiently small temperature chiral plasma is unstable with respect to condensation of Cooper pairs and dynamical chiral symmetry breaking even for vanishingly small interactions between constituents.

  4. Cis and Trans Isomers of Cycloalkenes

    Science.gov (United States)

    Barrows, Susan E.; Eberlein, Thomas H.

    2005-09-01

    As a rule, a trans disubstituted alkene is more stable than the corresponding cis isomer. For cycloalkenes of fewer than eleven members, cis isomers are more stable than their trans counterparts. Although this exception to the normal rule is occasionally noted in beginning organic chemistry textbooks, it is often done without a careful analysis of the reasons behind it. The purpose of this article is to provide that analysis. In order for a cycloalkene to accommodate a trans double bond one or more of the following nonideal geometries must occur: a twisted π bond; pyramidal sp 2 -carbon atoms; nonideal sp 3 bond angles; or longer than normal C C single and double bonds. This article provides a list of experimentally determined relative energies of the cis and trans isomers within the series cycloheptene cycloundecene, along with computationally derived energies at several levels of theory. It also examines the geometric distortions through which cycloalkenes relieve the strain introduced by a trans double bond.

  5. Stereochemical configuration and selective excitation of the chiral molecule halothane

    CERN Document Server

    Pitzer, Martin; Burzynski, Phillip; Weller, Miriam; Metz, Daniel; Neff, Jonathan; Waitz, Markus; Trinter, Florian; Schmidt, Lothar Ph H; Williams, Joshua B; Jahnke, Till; Schmidt-Böcking, Horst; Berger, Robert; Dörner, Reinhard; Schöffler, Markus

    2016-01-01

    X-ray single-photon ionization and fragmentation of the chiral molecule halothane (CHBrClCF${}_{3}$) from a racemic mixture have been investigated using the COLTRIMS (Cold Target Recoil Ion Momentum Spectroscopy) technique. Two important facets related to the core ionization of this species are examined: Firstly, the distinction of enantiomers (mirror isomers) and the determination of absolute configuration on a single-molecule level by four-body Coulomb explosion; secondly, the interplay of site-selective excitation and fragmentation patterns. These results are easily transferrable to other molecular species and show the wealth of features

  6. Chiral Brownian heat pump

    OpenAIRE

    Van Den Broek, Martijn; Van Den Broeck, Christian

    2007-01-01

    We present the exact analysis of a chiral Brownian motor and heat pump. Optimization of the construction predicts, for a nanoscale device, frequencies of the order of kHz and cooling rates of the order of femtojoule per second.

  7. Chiral brownian heat pump.

    Science.gov (United States)

    van den Broek, M; Van den Broeck, C

    2008-04-04

    We present the exact analysis of a chiral Brownian motor and heat pump. Optimization of the construction predicts, for a nanoscale device, frequencies of the order of kHz and cooling rates of the order of femtojoule per second.

  8. Color chiral solitons

    CERN Document Server

    Novozhilov, V Yu; Novozhilov, Victor; Novozhilov, Yuri

    2002-01-01

    We discuss specific features of color chiral solitons (asymptotics, possibility of confainment, quantization) at example of isolated SU(2) color skyrmions, i.e. skyrmions in a background field which is the vacuum field forming the gluon condensate.

  9. An Assessment of Nuclear Isomers as an Energy Storage Medium

    Energy Technology Data Exchange (ETDEWEB)

    Hartouni, E P

    2008-12-08

    Nuclear Isomers have been suggested as a potential high energy density medium that might be used to store energy. This talk assesses the state of the science supporting key elements of using nuclear isomers in energy storage applications. The focus is on the nuclear isomer {sup 178m2}Hf which has been most widely suggested for energy storage applications. However, the science issues apply to all nuclear isomer. The assessment addresses the production of the nuclear isomer, and inducing the release of the isomer. Also discussed are novel speculations on photon and/or neutron chain reactions, both as a 'pure' material as well as mixed with other materials.

  10. Two Novel Isomers of HPS3 System

    Institute of Scientific and Technical Information of China (English)

    Hai Tao YU; Ming Xia LI; Yu Juan CHI; Fu Long YUANG; Hong Gang FU; Jia Zhong SUN

    2003-01-01

    Two new isomers of HPS3 system, HP(S)S2 and HSSPS, are predicted by means of B3LYP method with 6-311++G(3df,3pd) basis set. The two isomers can isomerize into thermodynamically the most stable species HSPS2, which have been experimentally identified, with relatively higher reaction barriers. In view of their higher thermodynamical and kinetic stability and the experimental observation for HP(O)O2 and HOOPO in previous study, we can reasonably believe that the two species can be spectrosymmetrically characterized in future experiments.

  11. Analysis of Heme oxygenase isomers in rat

    Institute of Scientific and Technical Information of China (English)

    Yun-ZhuLi; Wen-JunCui; Xue-HongZhang; Qing-XiangShen; JianWang; She

    2002-01-01

    AIM:To purify and identify heme oxygenase(HO) isomers which exist in rat liver,spleen and brain treated with hematin and phenylhydrazine and in untrated rat liver and to investigate the characteristics of HO isomers,to isolate and confirm the rat HO-1 cDNA that actually encodes HO-1 by expressing cDNA in monkey Kidney cells(COS-1 cells),to prepare the rat heme oxygenase-1(HO-1)mutant and to detect inhibition of HO-1 mutated enzyme.

  12. Origin of Kinetic Resolution of Hydroxy Esters through Catalytic Enantioselective Lactonization by Chiral Phosphoric Acids.

    Science.gov (United States)

    Changotra, Avtar; Sunoj, Raghavan B

    2016-08-05

    Kinetic resolution is a widely used strategy for separation and enrichment of enantiomers. Using density functional theory computations, the origin of how a chiral BINOL-phosphoric acid catalyzes the selective lactonization of one of the enantiomers of α-methyl γ-hydroxy ester is identified. In a stepwise mechanism, the stereocontrolling transition state for the addition of the hydroxyl group to the si face of the ester carbonyl in the case of the S isomer exhibits a network of more effective noncovalent interactions between the substrate and the chiral catalyst.

  13. Gastric inflammatory markers and interleukins in patients with functional dyspepsia treated with astaxanthin

    DEFF Research Database (Denmark)

    Andersen, L.P.; Holck, Susanne; Kupcinskas, L.;

    2007-01-01

    The chronic active inflammation caused by Helicobacter pylori is dominated by neutrophils, macrophages, lymphocytes and plasma cells. Several interleukins are involved in the inflammatory process. The aim of this study was to investigate the effect of astaxanthin on gastric inflammation in patien...

  14. "Glucose and ethanol-dependent transcriptional regulation of the astaxanthin biosynthesis pathway in Xanthophyllomyces dendrorhous"

    Directory of Open Access Journals (Sweden)

    Cifuentes Víctor

    2011-08-01

    Full Text Available Abstract Background The yeast Xanthophyllomyces dendrorhous is one of the most promising and economically attractive natural sources of astaxanthin. The biosynthesis of this valuable carotenoid is a complex process for which the regulatory mechanisms remain mostly unknown. Several studies have shown a strong correlation between the carbon source present in the medium and the amount of pigments synthesized. Carotenoid production is especially low when high glucose concentrations are used in the medium, while a significant increase is observed with non-fermentable carbon sources. However, the molecular basis of this phenomenon has not been established. Results In this work, we showed that glucose caused transcriptional repression of the three genes involved in the synthesis of astaxanthin from geranylgeranyl pyrophosphate in X. dendrorhous, which correlates with a complete inhibition of pigment synthesis. Strikingly, this regulatory response was completely altered in mutant strains that are incapable of synthesizing astaxanthin. However, we found that addition of ethanol caused the induction of crtYB and crtS gene expression and promoted de novo synthesis of carotenoids. The induction of carotenogenesis was noticeable as early as 24 h after ethanol addition. Conclusion For the first time, we demonstrated that carbon source-dependent regulation of astaxanthin biosynthesis in X. dendrorhous involves changes at the transcriptional level. Such regulatory mechanism provides an explanation for the strong and early inhibitory effect of glucose on the biosynthesis of this carotenoid.

  15. Novel astaxanthin extraction from Haematococcus pluvialis using cell permeabilising ionic liquids

    NARCIS (Netherlands)

    Desai, R.K.; Streefland, M.; Wijffels, R.H.; Eppink, M.H.M.

    2016-01-01

    Haematococcus pluvialis (H. pluvialis) is a natural source of the food colorant astaxanthin. It is characterised by a thick resistant cell wall composed of a non-hydrolysable biopolymer, sporopollenin. High energy-consuming mechanical disruption is required to improve the extractability of astaxanth

  16. A developmental toxicity study of 3S, 3'S-Astaxanthin in New Zealand white rabbits.

    Science.gov (United States)

    Schneider, Steffen; Mellert, Werner; Schulte, Stefan; van Ravenzwaay, Bennard

    2016-04-01

    Astaxanthin, a naturally occurring pigment used to give the characteristic orange-pink colour to salmonid fish reared in aquaculture, is also marketed as a dietary supplement. Synthetic 3S, 3'S-Astaxanthin was tested for potential harmful effects on the in utero development of New Zealand white rabbits in a study according to international regulatory guidelines. There were two control groups, one being a placebo administration and three dose levels corresponding to 100, 200, and 400 mg of 3S, 3'S-Astaxanthin per kg body weight/day. The group sizes varied from 23 to 27 litters, providing approximately 200 fetuses per group for evaluation of developmental toxicity. There were no significant effects on the health of the does, nor on the size and viability of the litters. Malformations, both external and internal, were rare and occurred in all groups, including controls with no indication of a treatment relationship. Variations were much more common, being found in all litters. However, when examined by type and frequency, no pattern emerged indicating a relationship to administration of the test substance. It is concluded that administration of 3S, 3'S-Astaxanthin in a gelatin/carbohydrate powder formulation throughout pregnancy up to 400 mg/kg body weight/day is without harmful effects on reproduction or fetal development.

  17. PCR-based method for the rapid identification of astaxanthin-accumulating yeasts (Phaffia spp.).

    Science.gov (United States)

    Colabella, Fernando; Libkind, Diego

    2016-01-01

    It has been recently found that the natural distribution, habitat, and genetic diversity of astaxanthin-producing yeasts (i.e. Phaffia rhodozyma, synonym Xanthophyllomyces dendrorhous) is much greater than previously thought. P. rhodozyma is biotechnologically exploited due to its ability to produce the carotenoid pigment astaxanthin and thus, it is used as a natural source of this pigment for aquaculture. P. rhodozyma was also capable of synthesizing the potent UVB sunscreen mycosporine-glutaminol-glucoside (MGG). Therefore, further environmental studies are needed to elucidate its ecological aspects and detect new potential strains for the production of astaxanthin and MGG. However, obtaining new isolates of P. rhodozyma and related species is not always easy due to its low abundance and the presence of other sympatric and pigmented yeasts. In this work we report a successful development of a species-specific primer which has the ability to quickly and accurately detecting isolates representing all known lineages of the genus Phaffia (including novel species of the genus) and excluding closely related taxa. For this purpose, a primer of 20 nucleotides (called PhR) was designed to be used in combination with universal primers ITS3 and NL4 in a multiplex amplification. The proposed method has the sensitivity and specificity required for the precise detection of new isolates, and therefore represents an important tool for the environmental search for novel astaxanthin-producing yeasts.

  18. Stability of astaxanthin in yogurt used to simulate apricot color, under refrigeration

    Directory of Open Access Journals (Sweden)

    Pedro Cerezal Mezquita

    2014-09-01

    Full Text Available The aim of this study was to incorporate astaxanthin to yogurts with different fat content to match apricot (Prunus armeniaca L. color. The samples containing astaxanthin were stored at 5 ± 3 °C, and color stability and astaxanthin content were determined by colorimetry and high performance liquid chromatography (HPLC, respectively. Yogurt samples were analyzed in triplicate every 24 hours for one week and subsequently every week for 3 more weeks There were no significant differences (p < 0.05 between astaxanthin concentration values at 0 and 28 days for both samples; therefore, it can be said that the fat content in the yogurt had not effect on the stability of pigment. The low dispersion of the data showed uniformity in the three chromaticity coordinates L*, a*, b* throughout the storage period for both types of yogurt. Values of ∆E ≥ 5.0 were not obtained at any time during storage, indicating high stability of the pigment.

  19. Astaxanthin induction in Microalga H. pluvialis with flat panel airlift photobioreactors under indoor and outdoor conditions.

    Science.gov (United States)

    Poonkum, Woradej; Powtongsook, Sorawit; Pavasant, Prasert

    2015-01-01

    Astaxanthin was induced from Haematococcus pluvialis (NIES-144) under indoor and outdoor conditions using 17-, 50-, and 90-L flat-panel airlift photobioreactors (FP-APBRs). Preliminary experiments in 1.5-L bubble column photobioreactors (BC-PBRs) revealed that sterilized clean water with 3% CO2 aeration (1.47 cm(3) s(-1) CO2 loading) could best encourage astaxanthin accumulation at 18.21 g m(-3) (3.63% by weight). Operating 17-L FP-APBRs with these bubble column parameters under indoor conditions could further enhance astaxanthin to 26.63 g m(-3) (5.34% by weight). This was potentially due to the inherited up-lift force from the reactor that helped avoid cell precipitation by allowing the cells to be circulated within the reactor. In addition, the various sizes of FP-APBRs exhibited similar performance, implying a potential scale-up opportunity. However, similar operation under outdoor condition exhibited slightly poorer performance due to the light inhibition effect. The best outdoor performance was obtained with the FP-APBR covered with one layer of shading net, where 20.11 g m(-3) (4.47% by weight) of astaxanthin was resulted.

  20. Evaluation and screening of efficient promoters to improve astaxanthin production in Xanthophyllomyces dendrorhous.

    Science.gov (United States)

    Hara, Kiyotaka Y; Morita, Toshihiko; Endo, Yusuke; Mochizuki, Masao; Araki, Michihiro; Kondo, Akihiko

    2014-08-01

    Astaxanthin is a valuable carotenoid that is widely used in the aquaculture, food, pharmaceutical, and cosmetic industries. Xanthophyllomyces dendrorhous is a carotenoid-synthesizing yeast strain that produces astaxanthin as its main pigment. Although metabolic engineering using gene manipulation is a valuable way to improve astaxanthin production, a gene expression system for X. dendrorhous has been poorly developed. In this study, three known promoters of X. dendrorhous, glycerol-3-phosphate dehydrogenase (gpd) promoter (Pgpd), glucose dehydrogenase (gdh) promoter (Pgdh), and actin (act) promoter (Pact), were evaluated for use in the overexpression of target proteins using green fluorescence protein (GFP) as an expression level indicator protein. The actin promoter, Pact, showed the highest expression level of GFP when compared with Pgpd and Pgdh. Additionally, to obtain new promoters for higher expression of target protein in X. dendrorhous, intracellular GFP intensity was evaluated for 13 candidate promoters. An alcohol dehydrogenase promoter, Padh4, showed more efficient expression of GFP rather than Pact. Overexpression of crtE gene encoding rate-limiting enzyme of carotenoid synthesis under the adh4 promoter yielded an increase in intracellular astaxanthin content of about 1.7-fold compared with the control strain. The promoters identified in this study must be useful for improving carotenoids production in X. dendrorhous.

  1. Effects of different fungal elicitors on growth, total carotenoids and astaxanthin formation by Xanthophyllomyces dendrorhous.

    Science.gov (United States)

    Wang, Wenjun; Yu, Longjiang; Zhou, Pengpeng

    2006-01-01

    Six fungal elicitors prepared from Rhodotorula rubra, Rhodotorula glutinis, Panus conchatus, Coriolus versicolor, Mucor mucedo, Mortieralla alpina M-23 were examined to determine their effects on the growth, total carotenoids and astaxanthin formation by Xanthophyllomyces dendrorhous. The results showed that different fungal elicitor could cause diversely stimulating effects. Among the fungal elicitors tested, the M. mucedo elicitor concentration of 30 mg l(-1) promoted the biomass and total carotenoids yield most remarkably, resulting in 69.81+/-6.00% and 78.87+/-4.15% higher than the control, respectively. At the concentration of 30 mg l(-1), R. glutinis elicitor stimulated the highest astaxanthin yield with a 90.60+/-5.98% increase compared to the control. The R. rubra elicitor concentration of 30 mg l(-1) resulted in the optimal total carotenoids and astaxanthin content to be 42.24+/-0.49% and 69.02+/-0.72% higher than the control, respectively. At the concentration of 30 mg l(-1), R. rubra elicitor gave the highest increase in the ratio of astaxanthin in total carotenoids by 18.85+/-0.11% of the control.

  2. Electrodynamics of chiral matter

    Science.gov (United States)

    Qiu, Zebin; Cao, Gaoqing; Huang, Xu-Guang

    2017-02-01

    Many-body systems with chiral fermions can exhibit novel transport phenomena that violate parity and time-reversal symmetries, such as the chiral magnetic effect, the anomalous Hall effect, and the anomalous generation of charge. Based on the Maxwell-Chern-Simons electrodynamics, we examine some electromagnetic and optical properties of such systems including the electrostatics, the magnetostatics, the propagation of electromagnetic waves, the novel optical effects, etc.

  3. Chiral Odd GPDs

    Directory of Open Access Journals (Sweden)

    Goldstein Gary R.

    2015-01-01

    Full Text Available Nucleon spin structure, transversity and the tensor charge are of central importance to understanding the role of QCD in hadronic physics. A new approach to measuring orbital angular momenta of quarks in the proton via twist 3 GPDs is shown. The “flexible parametrization” of chiral even GPDs is reviewed and its transformation into the chiral odd sector is discussed. The resulting parametrization is applied to recent data on π0 and η electroproduction.

  4. A sensitivity-enhanced field-effect chiral sensor.

    Science.gov (United States)

    Torsi, Luisa; Farinola, Gianluca M; Marinelli, Francesco; Tanese, M Cristina; Omar, Omar Hassan; Valli, Ludovico; Babudri, Francesco; Palmisano, Francesco; Zambonin, P Giorgio; Naso, Francesco

    2008-05-01

    Organic thin-film transistor sensors have been recently attracting the attention of the plastic electronics community for their potential exploitation in novel sensing platforms. Specificity and sensitivity are however still open issues: in this respect chiral discrimination-being a scientific and technological achievement in itself--is indeed one of the most challenging sensor bench-tests. So far, conducting-polymer solid-state chiral detection has been carried out at part-per-thousand concentration levels. Here, a novel chiral bilayer organic thin-film transistor gas sensor--comprising an outermost layer with built-in enantioselective properties-is demonstrated to show field-effect amplified sensitivity that enables differential detection of optical isomers in the tens-of-parts-per-million concentration range. The ad-hoc-designed organic semiconductor endowed with chiral side groups, the bilayer structure and the thin-film transistor transducer provide a significant step forward in the development of a high-performance and versatile sensing platform compatible with flexible organic electronic technologies.

  5. Effect of feeding methods on the astaxanthin production by Phaffia rhodozyma in fed-batch process

    Directory of Open Access Journals (Sweden)

    Danilo Gomes Moriel

    2005-05-01

    Full Text Available The effect of feeding methods on the production of astaxanthin by the yeast Phaffia rhodozyma ATCC 24202 was studied, using continuous and pulsed fed-batch processes and low cost materials as substrates (sugar cane juice and urea. In continuous fed-batch processes, a cellular astaxanthin concentration of 383.73 µg/g biomass was obtained. But in pulsed fed-batch processes a reduction in the cellular astaxanthin concentration (303.34 µg/g biomass was observed. Thus the continuous fed-batch processes could be an alternative to industrial production of astaxanthin, allowing an increase in the biomass productivity without losses on astaxanthin production by the yeast.O efeito da alimentação na produção de astaxantina pela levedura Phaffia rhodozyma ATCC 24202 foi estudado, utilizando processos descontínuo alimentado com alimentação contínua e intermitente, e matérias-primas de baixo custo como substratos (caldo de cana de açúcar e uréia. Em processos descontínuo alimentado com alimentação contínua, uma concentração celular de astaxantina de 383,73 µg/g biomassa foi obtida. Entretanto, em processos descontínuo alimentado com alimentação intermitente, uma redução na concentração celular de astaxantina (303,34 µg/g biomassa foi observada. Desta forma, processos descontínuo alimentado com alimentação contínua poderiam ser uma alternativa na produção industrial de astaxantina, permitindo um aumento na produtividade de biomassa sem perdas na produção de astaxantina pela levedura.

  6. Effect of dietary Astaxanthin sources supplementation on muscle pigmentation and lipid peroxidation in rainbow trout (Oncorhynchus mykiss

    Directory of Open Access Journals (Sweden)

    Marco Saroglia

    2010-01-01

    Full Text Available Astaxanthin is one of the major carotenoids in aquatic animals including salmonid fishes and is the preferred pigments added to salmon feed. It’s also a powerful antioxidant compared to other carotenoids and that may confer numerous health benefits. The aim of the present experi- ment was to investigate the effect of Astaxanthin deposition on the lipids peroxidation by studying the Malondialdeide (MDA level in muscle of rainbow trout (Oncorhynchus mykiss. The Astaxanthin concentrations in fish fed with a commercial sources as Lucantin®Pink (BASF Ludwigshafen, Ger- many reached values to 5.76±0.18x10-3 mg/g after 50 days feeding, while the MDA concentration de- creased from 1.56x103 to 0.45x103 ng/g. The correlation between MDA and Astaxanthin concentrations decreased linearly and confirmed the antioxidant properties of the pigment by reducing the lipids peroxidation.

  7. Hepatic Transcriptome Profiles of Mice with Diet-Induced Nonalcoholic Steatohepatitis Treated with Astaxanthin and Vitamin E

    Directory of Open Access Journals (Sweden)

    Masuko Kobori

    2017-03-01

    Full Text Available Astaxanthin alleviates hepatic lipid accumulation and peroxidation, inflammation, and fibrosis in mice with high-cholesterol, high-cholate, and high-fat (CL diet-induced nonalcoholic steatohepatitis (NASH [...

  8. [Technological process of cell disruption for extracting astaxanthin from Phaffia rhodozyma by acid method under autoclave conditions].

    Science.gov (United States)

    Lu, Baoju; Xiao, Anfeng; Lil, Lijun; Ni, Hui; Cai, Huinong; Su, Wenjin

    2008-07-01

    Phaffia rhodozyma is one of the organisms for production of astaxanthin, and the key process for extracting intracellular astaxanthin is cell disruption. In this work, cell disruption for extracting astaxanthin from Phaffia rhodozyma was studied with autoclave method at low acid concentration. The optimum disrupting conditions were: autoclave pressure 0.1 MPa, 121 degrees C; hydrochloric acid concentration 0.5 mol/L; liquid to material ratio (V/W) 30 mL/g dry cell weight and disruption time 2 min. Under the optimum conditions, medium scale experiment showed that astaxanthin and total carotenoids recovery from Phaffia rhodozyma were (84.8 +/- 3.2)% and (93.3 +/- 2)%, respectively. This new method can lead to no poisonous residues and get high extraction yield, which have good prospects to be put into industrial production.

  9. Astaxanthin down-regulates Rad51 expression via inactivation of AKT kinase to enhance mitomycin C-induced cytotoxicity in human non-small cell lung cancer cells.

    Science.gov (United States)

    Ko, Jen-Chung; Chen, Jyh-Cheng; Wang, Tai-Jing; Zheng, Hao-Yu; Chen, Wen-Ching; Chang, Po-Yuan; Lin, Yun-Wei

    2016-04-01

    Astaxanthin has been demonstrated to exhibit a wide range of beneficial effects, including anti-inflammatory and anti-cancer properties. However, the molecular mechanism of astaxanthin-induced cytotoxicity in non-small cell lung cancer (NSCLC) cells has not been identified. Rad51 plays a central role in homologous recombination, and studies show that chemo-resistant carcinomas exhibit high levels of Rad51 expression. In this study, astaxanthin treatment inhibited cell viability and proliferation of two NSCLC cells, A549 and H1703. Astaxanthin treatment (2.5-20 μM) decreased Rad51 expression and phospho-AKT(Ser473) protein level in a time and dose-dependent manner. Furthermore, expression of constitutively active AKT (AKT-CA) vector rescued the decreased Rad51 mRNA and protein levels in astaxanthin-treated NSCLC cells. Combined treatment with phosphatidylinositol 3-kinase (PI3K) inhibitors (LY294002 or wortmannin) further decreased the Rad51 expression in astaxanthin-exposed A549 and H1703 cells. Knockdown of Rad51 expression by transfection with si-Rad51 RNA or cotreatment with LY294002 further enhanced the cytotoxicity and cell growth inhibition of astaxanthin. Additionally, mitomycin C (MMC) as an anti-tumor antibiotic is widely used in clinical NSCLC chemotherapy. Combination of MMC and astaxanthin synergistically resulted in cytotoxicity and cell growth inhibition in NSCLC cells, accompanied with reduced phospho-AKT(Ser473) level and Rad51 expression. Overexpression of AKT-CA or Flag-tagged Rad51 reversed the astaxanthin and MMC-induced synergistic cytotoxicity. In contrast, pretreatment with LY294002 further decreased the cell viability in astaxanthin and MMC co-treated cells. In conclusion, astaxanthin enhances MMC-induced cytotoxicity by decreasing Rad51 expression and AKT activation. These findings may provide rationale to combine astaxanthin with MMC for the treatment of NSCLC.

  10. Organometallic chemistry: Heavyweight isomer brings stability

    Science.gov (United States)

    Scheschkewitz, David

    2016-11-01

    Due to its high reactivity, vinylidene -- the sole 'electron-precise' isomer of acetylene -- is only known to exist in the gas phase. Now, a stable base-free digermanium version of a vinylidene has been isolated by the clever use of suitable substituents.

  11. A new isomer in {sup 125}La

    Energy Technology Data Exchange (ETDEWEB)

    Canchel, G. [Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire]|[Department of Physics, Accelerator Laboratory, University of Jyvaeskylae, P.O. Box 35, FIN-40351 Jyvaeskylae (Finland); Beraud, R.; Chabanat, E.; Emsallem, A.; Redon, N. [Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire; Dendooven, P.; Huikari, J.; Jokinen, A.; Kolhinen, V.; Lhersonneau, G.; Oinonen, M.; Nieminen, A.; Penttilae, H.; Peraejaervi, K.; Wang, J.C.; Aeystoe, J. [Department of Physics, Accelerator Laboratory, University of Jyvaeskylae, P.O. Box 35, FIN-40351 Jyvaeskylae (Finland)

    1999-05-01

    Levels in {sup 125}La have been studied via {beta}{sup +}/EC decay of on-line mass-separated {sup 125}Ce using the HIGISOL technique. A new (390{+-}40) ms isomer is definitely attributed to {sup 125}La by conversion electron measurements of the 107 keV E3 isomeric transition. (orig.) With 2 figs., 1 tab., 11 refs.

  12. OPTIMISATION OF SUPERCRITICAL FLUID EXTRACTION OF ASTAXANTHIN FROM PENAEUS MONODON WASTE USING ETHANOL-MODIFIED CARBON DIOXIDE

    Directory of Open Access Journals (Sweden)

    SHAZANA A. RADZALI

    2016-05-01

    Full Text Available Some studies demonstrated that astaxanthin surpasses the antioxidant benefits of beta-carotene, zeaxanthin, canthaxanthin, vitamin C, and vitamin E. Penaeus monodon (Tiger shrimp is one of the most valuable traded crustacean products in which astaxanthin can be found in its by-products. The extraction of thermolabile compound like carotenoids at lower temperatures through supercritical carbon dioxide (SC-CO2 can reduce the potential isomerization and degradation of the extraction product. In this study, astaxanthin had been extracted using SC-CO2 with 15% (v/v ethanol as an entrainer and the recovered astaxanthin was analyzed using High performance liquid chromatography (HPLC. A central composite design (CCD was employed to study the effect of three SC-CO2 parameters namely temperature (X1 from 40 to 80°C, pressure (X2 from 150 to 250 bar and extraction flow rate (X3 from 1 to 3 ml/min on the astaxanthin complex yield, (Y1 and free astaxanthin content, (Y2. The nonlinear regression equations were significantly (p0.9261, which had no indication of lack of fit. The results indicated that a combined set of values of temperature (56.88°C, pressure (215.68 bar and extraction flow rate (1.89 ml/min was predicted to provide the optimum region in terms of astaxanthin complex yield, (58.50 ± 2.62 µg/g and free astaxanthin content (12.20 ± 4.16 µg/g studied.

  13. Effects of Dietary Inclusion of Astaxanthin on Growth, Muscle Pigmentation and Antioxidant Capacity of Juvenile Rainbow Trout (Oncorhynchus mykiss)

    Science.gov (United States)

    Rahman, Md Mostafizur; Khosravi, Sanaz; Chang, Kyung Hoon; Lee, Sang-Min

    2016-01-01

    This study was designed to investigate the effects of dietary astaxanthin levels on growth performance, feed utilization, muscle pigmentation, and antioxidant capacity in juvenile rainbow trout. Four experimental diets were formulated to contain 0, 50, 75, and 100 mg/kg astaxanthin (designed as AX0, AX50, AX75, and AX100). Each diet was fed to triplicate groups of fish (18.5 g/fish) for 10 weeks. Growth performance and muscle composition of fish were not affected by dietary astaxanthin levels. Total carotenoid concentration in the muscle of fish fed the AX50 diet was higher than that of fish fed the AX0 diet, but no significant differences were observed between these fish and those fed the AX75 and AX100 diets. Muscle astaxanthin content increased with increased astaxanthin in the diet. Deposition of astaxanthin in the flesh resulted in a decrease in lightness and an increase in redness and yellowness. The fillets from trout fed the AX75 diet had significantly lower lightness than trout fed the AX50 and AX100 diets. Fish fed the AX50 and AX75 diets showed significantly lower catalase activity than those fed the control diet. Total antioxidant status increased significantly in all astaxanthin supplemented groups when compared to the control group. Superoxide dismutase activity was significantly decreased in fish fed the AX50 diet compared to fish fed the AX0 diet. These findings suggest that while fillet pigmentation increased with increasing dietary astaxanthin concentration, indices of fish antioxidant capacity may not be affected in a dose dependent manner. PMID:27752505

  14. Chiral Random Matrix Theory and Chiral Perturbation Theory

    CERN Document Server

    Damgaard, P H

    2011-01-01

    Spontaneous breaking of chiral symmetry in QCD has traditionally been inferred indirectly through low-energy theorems and comparison with experiments. Thanks to the understanding of an unexpected connection between chiral Random Matrix Theory and chiral Perturbation Theory, the spontaneous breaking of chiral symmetry in QCD can now be shown unequivocally from first principles and lattice simulations. In these lectures I give an introduction to the subject, starting with an elementary discussion of spontaneous breaking of global symmetries.

  15. Chiral Random Matrix Theory and Chiral Perturbation Theory

    Energy Technology Data Exchange (ETDEWEB)

    Damgaard, Poul H, E-mail: phdamg@nbi.dk [Niels Bohr International Academy and Discovery Center, The Niels Bohr Institute, Blegdamsvej 17, DK-2100 Copenhagen (Denmark)

    2011-04-01

    Spontaneous breaking of chiral symmetry in QCD has traditionally been inferred indirectly through low-energy theorems and comparison with experiments. Thanks to the understanding of an unexpected connection between chiral Random Matrix Theory and chiral Perturbation Theory, the spontaneous breaking of chiral symmetry in QCD can now be shown unequivocally from first principles and lattice simulations. In these lectures I give an introduction to the subject, starting with an elementary discussion of spontaneous breaking of global symmetries.

  16. The synthesis of astaxanthin esters,independent of the formation of cysts,highly correlates with the synthesis of fatty acids in Haematococcus pluvialis

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The compositions and contents of astaxanthin esters and fatty acids in four types of Haematococcus pluvialis cells were studied by HPLC and GC-MS. Results showed that the synthesis and accumulation of astaxanthin was independent of the formation of cysts, but was highly correlated with the synthesis and accumulation of fatty acids, though it is an well known phenomenon that the accumulation of astaxanthin is usually accompanied by the formation of cyst. The red cysts contain more than 30% of fatty acids, with 81% of the unsaturated fatty acids. Taken together, besides a resource of astaxanthin, H. pluvialis would be a good resource of valuable fatty acids.

  17. The synthesis of astaxanthin esters, independent of the formation of cysts, highly correlates with the synthesis of fatty acids in Haematococcus pluvialis

    Institute of Scientific and Technical Information of China (English)

    MIAO FengPing; LU DaYan; ZHANG ChengWu; ZUO JinCheng; GENG YaHong; HU HongJun; LI YeGuang

    2008-01-01

    The compositions and contents of astaxanthin esters and fatty acids in four types of Haematococcus pluvialis cells were studied by HPLC and GC-MS. Results showed that the synthesis and accumulation of astaxanthin was independent of the formation of cysts, but was highly correlated with the synthesis and accumulation of fatty acids, though it is an well known phenomenon that the accumulation of astaxanthin is usually accompanied by the formation of cyst. The red cysts contain more than 30% of fatty acids, with 81% of the unsaturated fatty acids. Taken together, besides a resource of astaxanthin, H. Pluvialis would be a good resource of valuable fatty acids.

  18. Construction of transplastomic lettuce (Lactuca sativa) dominantly producing astaxanthin fatty acid esters and detailed chemical analysis of generated carotenoids.

    Science.gov (United States)

    Harada, Hisashi; Maoka, Takashi; Osawa, Ayako; Hattan, Jun-Ichiro; Kanamoto, Hirosuke; Shindo, Kazutoshi; Otomatsu, Toshihiko; Misawa, Norihiko

    2014-04-01

    The plastid genome of lettuce (Lactuca sativa L.) cv. Berkeley was site-specifically modified with the addition of three transgenes, which encoded β,β-carotenoid 3,3'-hydroxylase (CrtZ) and β,β-carotenoid 4,4'-ketolase (4,4'-oxygenase; CrtW) from a marine bacterium Brevundimonas sp. strain SD212, and isopentenyl diphosphate isomerase from a marine bacterium Paracoccus sp. strain N81106. Constructed transplastomic lettuce plants were able to grow on soil at a growth rate similar to that of non-transformed lettuce cv. Berkeley and generate flowers and seeds. The germination ratio of the lettuce transformants (T0) (98.8%) was higher than that of non-transformed lettuce (93.1 %). The transplastomic lettuce (T1) leaves produced the astaxanthin fatty acid (myristate or palmitate) diester (49.2% of total carotenoids), astaxanthin monoester (18.2%), and the free forms of astaxanthin (10.0%) and the other ketocarotenoids (17.5%), which indicated that artificial ketocarotenoids corresponded to 94.9% of total carotenoids (230 μg/g fresh weight). Native carotenoids were there lactucaxanthin (3.8%) and lutein (1.3 %) only. This is the first report to structurally identify the astaxanthin esters biosynthesized in transgenic or transplastomic plants producing astaxanthin. The singlet oxygen-quenching activity of the total carotenoids extracted from the transplastomic leaves was similar to that of astaxanthin (mostly esterified) from the green algae Haematococcus pluvialis.

  19. Astaxanthin present in the maturation medium reduces negative effects of heat shock on the developmental competence of porcine oocytes.

    Science.gov (United States)

    Do, Lanh Thi Kim; Luu, Vien Viet; Morita, Yasuhiro; Taniguchi, Masayasu; Nii, Masahiro; Peter, Augustine T; Otoi, Takeshige

    2015-06-01

    Astaxanthin, one of the most common carotenoids, elicits antioxidant effects on cellular viability and embryonic development. This study was conducted to investigate the effects of astaxanthin on maturation, fertilization and development of porcine oocytes matured in vitro under heat stress conditions, and then fertilized and cultured under standard conditions. Porcine oocytes were cultured in maturation medium supplemented with different concentrations of astaxanthin (0, 0.25, 0.5 or 1 ppm) for 46 h at either 38.5 or 41 °C. In comparison to oocytes cultured at 38.5 °C, the exposure of porcine oocytes to 41.0 °C during in vitro maturation (IVM) significantly inhibited maturation and development of fertilized oocytes to the blastocyst stage. Supplementation of maturation medium with astaxanthin (0.5 ppm) significantly improved oocyte maturation, fertilization and development to the blastocysts stage in both oocyte groups. However, the total cell number and apoptosis index of blastocysts did not differ among groups. Moreover, astaxanthin (0.5 ppm) significantly increased the rate of oocytes that reached metaphase II and decreased proportion of apoptotic oocytes exposed to H2O2 (1.0mM) during IVM. In summary, we demonstrated that supplementation of maturation medium with astaxanthin (0.5 ppm) exerted antioxidative effects and improved the ability of maturation, fertilization, and development of porcine oocytes exposed to heat stress.

  20. Dietary Carotenoids Regulate Astaxanthin Content of Copepods and Modulate Their Susceptibility to UV Light and Copper Toxicity

    Directory of Open Access Journals (Sweden)

    Kevin R. Carman

    2012-04-01

    Full Text Available High irradiation and the presence of xenobiotics favor the formation of reactive oxygen species in marine environments. Organisms have developed antioxidant defenses, including the accumulation of carotenoids that must be obtained from the diet. Astaxanthin is the main carotenoid in marine crustaceans where, among other functions, it scavenges free radicals thus protecting cell compounds against oxidation. Four diets with different carotenoid composition were used to culture the meiobenthic copepod Amphiascoides atopus to assess how its astaxanthin content modulates the response to prooxidant stressors. A. atopus had the highest astaxanthin content when the carotenoid was supplied as astaxanthin esters (i.e., Haematococcus meal. Exposure to short wavelength UV light elicited a 77% to 92% decrease of the astaxanthin content of the copepod depending on the culture diet. The LC50 values of A. atopus exposed to copper were directly related to the initial astaxanthin content. The accumulation of carotenoids may ascribe competitive advantages to certain species in areas subjected to pollution events by attenuating the detrimental effects of metals on survival, and possibly development and fecundity. Conversely, the loss of certain dietary items rich in carotenoids may be responsible for the amplification of the effects of metal exposure in consumers.

  1. The antioxidant effect of astaxanthin is higher in young mice than aged: a region specific study on brain.

    Science.gov (United States)

    Al-Amin, Md Mamun; Akhter, Samiha; Hasan, Ahmed Tasdid; Alam, Tanzir; Nageeb Hasan, S M; Saifullah, A R M; Shohel, Mohammad

    2015-10-01

    Astaxanthin is a potential antioxidant which shows neuroprotective property. We aimed to investigate the age-dependent and region-specific antioxidant effects of astaxanthin in mice brain. Animals were divided into 4 groups; treatment young (3 months, n = 6) (AY), treatment old (16 months, n = 6) (AO), placebo young (3 months, n = 6) (PY) and placebo old (16 months, n = 6) (PO) groups. Treatment group was given astaxanthin (2 mg/kg/day, body weight), and placebo group was given 100 μl of 0.9% normal saline orally to the healthy Swiss albino mice for 4 weeks. The level of non-enzymatic oxidative markers namely malondialdehyde (MDA); nitric oxide (NO); advanced protein oxidation product (APOP); glutathione (GSH) and the activity of enzymatic antioxidants i.e.; catalase (CAT) and superoxide dismutase (SOD) were determined from the isolated brain regions. Treatment with astaxanthin significantly (p Astaxanthin markedly (p astaxanthin is age-dependent, higher in young in compared to the aged brain.

  2. [Astaxanthin inhibits proliferation and promotes apoptosis of A549 lung cancer cells via blocking JAK1/STAT3 pathway].

    Science.gov (United States)

    Wu, Chuntao; Zhang, Jinji; Liu, Tienan; Jiao, Guimei; Li, Changzai; Hu, Baoshan

    2016-06-01

    Objective To investigate the anti-tumor effects of astaxanthin on A549 lung cancer cells and the related mechanisms. Methods A549 cells were cultured with various concentrations of astaxanthin (20, 40, 60, 80, 100 μmol/L), and DMSO at the same concentrations served as vehicle controls. The viability of A549 cells was detected by CCK-8 assay; cell cycle and apoptosis were observed by flow cytometry; and the expressions of B-cell lymphoma-2 (Bcl-2), Bcl-2 associated X protein (Bax), signal transducers and activators of transcription 3 (STAT3), and Janus kinase 1 (JAK1) were evaluated by Western blotting. Results CCK-8 assay showed that astaxanthin decreased the proliferation of A549 cells in a dose-dependent manner. Flow cytometry showed that astaxanthin increased the number of cells in the G0/G1 phase and induced apoptosis in A549 cells. Western blotting showed that astaxanthin up-regulated the expression of Bax and down-regulated the expressions of Bcl-2, STAT3 and JAK1. Conclusion Astaxanthin functions as a potent inhibitor of A549 lung cancer cell growth by targeting JAK1/STAT3 signaling pathway.

  3. Dietary carotenoids regulate astaxanthin content of copepods and modulate their susceptibility to UV light and copper toxicity.

    Science.gov (United States)

    Caramujo, Maria-José; de Carvalho, Carla C C R; Silva, Soraya J; Carman, Kevin R

    2012-05-01

    High irradiation and the presence of xenobiotics favor the formation of reactive oxygen species in marine environments. Organisms have developed antioxidant defenses, including the accumulation of carotenoids that must be obtained from the diet. Astaxanthin is the main carotenoid in marine crustaceans where, among other functions, it scavenges free radicals thus protecting cell compounds against oxidation. Four diets with different carotenoid composition were used to culture the meiobenthic copepod Amphiascoides atopus to assess how its astaxanthin content modulates the response to prooxidant stressors. A. atopus had the highest astaxanthin content when the carotenoid was supplied as astaxanthin esters (i.e., Haematococcus meal). Exposure to short wavelength UV light elicited a 77% to 92% decrease of the astaxanthin content of the copepod depending on the culture diet. The LC(50) values of A. atopus exposed to copper were directly related to the initial astaxanthin content. The accumulation of carotenoids may ascribe competitive advantages to certain species in areas subjected to pollution events by attenuating the detrimental effects of metals on survival, and possibly development and fecundity. Conversely, the loss of certain dietary items rich in carotenoids may be responsible for the amplification of the effects of metal exposure in consumers.

  4. The Bioavailability of Astaxanthin Is Dependent on Both the Source and the Isomeric Variants of the Molecule

    Directory of Open Access Journals (Sweden)

    Myriam MIMOUN-BENARROCH

    2016-11-01

    Full Text Available Astaxanthin is a marine carotenoid that has a number of potential health benefits, including a very strong antioxidant potential. Present in the flesh of salmonids and shellfish, its natural sources currently on the market for food supplements come from the algae Haematococcus pluvialis and krill. However other natural sources can be found and may be of interest. Cellular uptake studies were performed on Caco-2/TC7 colonic cells. The cells were cultured on a semi-permeable membrane to create a polarized and functional epithelium, representative of the intestinal barrier. Four sources of astaxanthin were selected and compared; synthetic, natural extracts from bacteria, algae or yeast. Astaxanthin was incorporated at a concentration of 5µM into mixed micelles and applied to cultured cells and concentration of astaxanthin measured by HPLC in both apical and basolateral compartments. Small variations in bioavailability were observed at 3 hours. After 6 hours, only the algae source of astaxanthin was still present in the apical compartment as the esterified form. Structure-activity relationships are further discussed. Animal experiments using yeast and algae sources in different types of matrices confirm the role of source and formulation in the bioavailability potential of astaxanthin.

  5. Effects of homogenization process parameters on physicochemical properties of astaxanthin nanodispersions prepared using a solvent-diffusion technique.

    Science.gov (United States)

    Anarjan, Navideh; Jafarizadeh-Malmiri, Hoda; Nehdi, Imededdine Arbi; Sbihi, Hassen Mohamed; Al-Resayes, Saud Ibrahim; Tan, Chin Ping

    2015-01-01

    Nanodispersion systems allow incorporation of lipophilic bioactives, such as astaxanthin (a fat soluble carotenoid) into aqueous systems, which can improve their solubility, bioavailability, and stability, and widen their uses in water-based pharmaceutical and food products. In this study, response surface methodology was used to investigate the influences of homogenization time (0.5-20 minutes) and speed (1,000-9,000 rpm) in the formation of astaxanthin nanodispersions via the solvent-diffusion process. The product was characterized for particle size and astaxanthin concentration using laser diffraction particle size analysis and high performance liquid chromatography, respectively. Relatively high determination coefficients (ranging from 0.896 to 0.969) were obtained for all suggested polynomial regression models. The overall optimal homogenization conditions were determined by multiple response optimization analysis to be 6,000 rpm for 7 minutes. In vitro cellular uptake of astaxanthin from the suggested individual and multiple optimized astaxanthin nanodispersions was also evaluated. The cellular uptake of astaxanthin was found to be considerably increased (by more than five times) as it became incorporated into optimum nanodispersion systems. The lack of a significant difference between predicted and experimental values confirms the suitability of the regression equations connecting the response variables studied to the independent parameters.

  6. Effects of astaxanthin-enriched yeast on mucosal IgA induction in the jejunum and ileum of weanling mice.

    Science.gov (United States)

    Nagayama, Tatsuhiko; Sugimoto, Miki; Ikeda, Shuntaro; Kume, Shinichi

    2014-04-01

    The present study was conducted to clarify the effects of astaxanthin-enriched yeast on the concentration of immunoglobulin A (IgA), the numbers of IgA antibody-secreting cells (ASC) and the messenger RNA (mRNA) expression of IgA C-region in the jejunum and ileum of weanling mice. Weanling mice were fed rodent feed or astaxanthin-enriched yeast-supplemented rodent feed for 7, 14 or 21 days. Supplemental astaxanthin-enriched yeast increased the numbers of IgA ASC in the jejunum and ileum after 7, 14 and 21 days of treatment. Supplemental astaxanthin-enriched yeast increased IgA concentrations in the jejunum after 21 days of treatment, but IgA concentrations in the ileum were not affected by the treatment. The mRNA expressions of IgA C-region in the jejunum after 14 and 21 days of treatment and the ileum after 14 days of treatment were enhanced by supplementation of astaxanthin-enriched yeast. These results indicate that supplementation of astaxanthin-enriched yeast is effective to enhance the numbers of IgA ASC in the jejunum and ileum and IgA concentrations in the ileum of weanling mice.

  7. Three-dimensional ultrastructural study of oil and astaxanthin accumulation during encystment in the green alga Haematococcus pluvialis.

    Directory of Open Access Journals (Sweden)

    Marina Wayama

    Full Text Available Haematococcus pluvialis is a freshwater species of green algae and is well known for its accumulation of the strong antioxidant astaxanthin, which is used in aquaculture, various pharmaceuticals, and cosmetics. High levels of astaxanthin are present in cysts, which rapidly accumulate when the environmental conditions become unfavorable for normal cell growth. It is not understood, however, how accumulation of high levels of astaxanthin, which is soluble in oil, becomes possible during encystment. Here, we performed ultrastructural 3D reconstruction based on over 350 serial sections per cell to visualize the dynamics of astaxanthin accumulation and subcellular changes during the encystment of H. pluvialis. This study showcases the marked changes in subcellular elements, such as chloroplast degeneration, in the transition from green coccoid cells to red cyst cells during encystment. In green coccoid cells, chloroplasts accounted for 41.7% of the total cell volume, whereas the relative volume of astaxanthin was very low (0.2%. In contrast, oil droplets containing astaxanthin predominated in cyst cells (52.2%, in which the total chloroplast volume was markedly decreased (9.7%. Volumetric observations also demonstrated that the relative volumes of the cell wall, starch grains, pyrenoids, mitochondria, the Golgi apparatus, and the nucleus in a cyst cell are smaller than those in green coccid cells. Our data indicated that chloroplasts are degraded, resulting in a net-like morphology, but do not completely disappear, even at the red cyst stage.

  8. Superconductivity in a chiral nanotube

    Science.gov (United States)

    Qin, F.; Shi, W.; Ideue, T.; Yoshida, M.; Zak, A.; Tenne, R.; Kikitsu, T.; Inoue, D.; Hashizume, D.; Iwasa, Y.

    2017-02-01

    Chirality of materials are known to affect optical, magnetic and electric properties, causing a variety of nontrivial phenomena such as circular dichiroism for chiral molecules, magnetic Skyrmions in chiral magnets and nonreciprocal carrier transport in chiral conductors. On the other hand, effect of chirality on superconducting transport has not been known. Here we report the nonreciprocity of superconductivity--unambiguous evidence of superconductivity reflecting chiral structure in which the forward and backward supercurrent flows are not equivalent because of inversion symmetry breaking. Such superconductivity is realized via ionic gating in individual chiral nanotubes of tungsten disulfide. The nonreciprocal signal is significantly enhanced in the superconducting state, being associated with unprecedented quantum Little-Parks oscillations originating from the interference of supercurrent along the circumference of the nanotube. The present results indicate that the nonreciprocity is a viable approach toward the superconductors with chiral or noncentrosymmetric structures.

  9. Chiral anomalies and differential geometry

    Energy Technology Data Exchange (ETDEWEB)

    Zumino, B.

    1983-10-01

    Some properties of chiral anomalies are described from a geometric point of view. Topics include chiral anomalies and differential forms, transformation properties of the anomalies, identification and use of the anomalies, and normalization of the anomalies. 22 references. (WHK)

  10. Quarkyonic Chiral Spirals

    CERN Document Server

    Kojo, Toru; McLerran, Larry; Pisarski, Robert D

    2009-01-01

    We consider the formation of chiral density waves in Quarkyonic matter, which is a phase where cold, dense quarks experience confining forces. We model confinement following Gribov and Zwanziger, taking the gluon propagator, in Coulomb gauge and momentum space, as 1/(p^2)^2. We assume that the number of colors, N, is large, and that the quark chemical potential, mu, is much larger than renormalization mass scale, Lambda_QCD. To leading order in 1/N and Lambda_QCD, a gauge theory with Nf flavors of massless quarks in 3+1 dimensions naturally reduces to a gauge theory in 1+1 dimensions, with an enlarged flavor symmetry of SU(2Nf). Through an anomalous chiral rotation, in two dimensions a Fermi sea of massless quarks maps directly onto the corresponding theory in vacuum. A chiral condensate forms locally, and varies with the spatial position, z, as . Following Schon and Thies, we term this two dimensional pion condensate a (Quarkyonic) chiral spiral. Massive quarks also exhibit chiral spirals, with the magnitude...

  11. Understanding the endocrine disruption of chiral pesticides:The enantioselectivity in estrogenic activity of synthetic pyrethroids

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Synthetic pyrethroids(SPs) ,a family of chiral insecticides consisting of multiple stereoismers,have been regarded as estrogenic endocrine-disrupting chemicals(EDCs) .In this study,we applied the yeast two-hybrid and molecular docking(MD) assay to assess the enantioselective estrogenic activities of three commonly used SPs,bifenthrin(cis-BF) ,permethrin(PM) and fenvalerate(Fen) .The β-galactosidase analyses indicated that all of the testing pyrethroids displayed significant(p<0.05) enantioselectivity.The results showed that the estrogenic potential of cis-BF was mainly attributed to 1S-cis-BF.Neither PM nor Fen showed estrogenic effects.However,two stereoisomers of PM possessed estrogenic potential activities.αR-2R-Fen and αS-2S-Fen also induced the β-galactosidase activity.The inability to initiate the reporter gene expression by the racemic chemicals may be due to the low ratios of these isomers or the antagonism among them.The strong hydrophobic interaction and the hydrogen bond between positive estrogenic isomers and ERα support our biological testing results.This research demonstrated that the enantioselective estrogenic activity of chiral SPs was due to selective binding between their isomers and the ERαreceptor.The data suggests that enantioselectivity of these chiral pesticides is significant to their estrogenic activities.

  12. Chirality and Pinwheels

    Science.gov (United States)

    Rodriguez-Fernandez, Emilio

    2013-01-01

    By using cardboard models that resemble propellers, the students of inorganic courses can easily visualizing the distinct rotation of optical isomers. These propellers rotate clockwise or counterclockwise when they are dropped from a certain height or in the presence of wind. (Contains 1 figure.)

  13. Chiral Synthons in Pesticide Syntheses

    NARCIS (Netherlands)

    Feringa, Bernard

    1988-01-01

    The use of chiral synthons in the preparation of enantiomerically pure pesticides is described in this chapter. Several routes to chiral synthons based on asymmetric synthesis or on natural products are illustrated. Important sources of chiral building blocks are reviewed. Furthermore the implicatio

  14. Chiral fermions on the lattice

    CERN Document Server

    Jahn, O; Jahn, Oliver; Pawlowski, Jan M.

    2002-01-01

    We discuss topological obstructions to putting chiral fermions on an even dimensional lattice. The setting includes Ginsparg-Wilson fermions, but is more general. We prove a theorem which relates the total chirality to the difference of generalised winding numbers of chiral projection operators. For an odd number of Weyl fermions this implies that particles and anti-particles live in topologically different spaces.

  15. [Chirality and drugs].

    Science.gov (United States)

    Testa, B; Reist, M; Carrupt, P A

    2000-07-01

    The two enantiomers of a chiral drug may have vastly different pharmacodynamic and pharmacokinetic properties. As a result, the research and development of chiral drugs raises specific problems some of which are discussed here. Thus, various pharmacokinetic interactions may involve two enantiomers, as seen for example when one enantiomer inhibits the metabolism of the other and modifies its effects. A different situation occurs when a third compound stereoselectively inhibits the metabolism of one of the two enantiomers. Another problem examined here results from the lack of configurational stability of some chiral drugs, a little known phenomenon whose consequences can be of pharmacological or pharmaceutical significance depending on the rate of the reaction of racemization or epimerisation. In-depth investigations are needed before choosing between a eutomer or a racemate.

  16. Doped Chiral Polymer Metamaterials

    Science.gov (United States)

    Park, Cheol (Inventor); Kang, Jin Ho (Inventor); Gordon, Keith L. (Inventor); Sauti, Godfrey (Inventor); Lowther, Sharon E. (Inventor); Bryant, Robert G. (Inventor)

    2017-01-01

    Some implementations provide a composite material that includes a first material and a second material. In some implementations, the composite material is a metamaterial. The first material includes a chiral polymer (e.g., crystalline chiral helical polymer, poly-.gamma.-benzyl-L-glutamate (PBLG), poly-L-lactic acid (PLA), polypeptide, and/or polyacetylene). The second material is within the chiral polymer. The first material and the second material are configured to provide an effective index of refraction value for the composite material of 1 or less. In some implementations, the effective index of refraction value for the composite material is negative. In some implementations, the effective index of refraction value for the composite material of 1 or less is at least in a wavelength of one of at least a visible spectrum, an infrared spectrum, a microwave spectrum, and/or an ultraviolet spectrum.

  17. Chiral Quantum Optics

    CERN Document Server

    Lodahl, Peter; Stobbe, Søren; Schneeweiss, Philipp; Volz, Jürgen; Rauschenbeutel, Arno; Pichler, Hannes; Zoller, Peter

    2016-01-01

    At the most fundamental level, the interaction between light and matter is manifested by the emission and absorption of single photons by single quantum emitters. Controlling light--matter interaction is the basis for diverse applications ranging from light technology to quantum--information processing. Many of these applications are nowadays based on photonic nanostructures strongly benefitting from their scalability and integrability. The confinement of light in such nanostructures imposes an inherent link between the local polarization and propagation direction of light. This leads to {\\em chiral light--matter interaction}, i.e., the emission and absorption of photons depend on the propagation direction and local polarization of light as well as the polarization of the emitter transition. The burgeoning research field of {\\em chiral quantum optics} offers fundamentally new functionalities and applications both for single emitters and ensembles thereof. For instance, a chiral light--matter interface enables...

  18. Chiral quark model

    Indian Academy of Sciences (India)

    H Weigel

    2003-11-01

    In this talk I review studies of hadron properties in bosonized chiral quark models for the quark flavor dynamics. Mesons are constructed from Bethe–Salpeter equations and baryons emerge as chiral solitons. Such models require regularization and I show that the two-fold Pauli–Villars regularization scheme not only fully regularizes the effective action but also leads the scaling laws for structure functions. For the nucleon structure functions the present approach serves to determine the regularization prescription for structure functions whose leading moments are not given by matrix elements of local operators. Some numerical results are presented for the spin structure functions.

  19. Modelling Study of Interstellar Ethanimine Isomers

    Science.gov (United States)

    Quan, Donghui; Herbst, Eric; Corby, Joanna F.; Durr, Allison; Hassel, George

    2016-06-01

    Ethanimine (CH3CHNH) , including both the E- and Z- isomers, were detected towards the star-forming region Sgr B2(N) using the GBT PRIMOS data (Loomis et al 2013), and were recently imaged by the ACTA (Corby et al. 2015). These aldimines can serve as precursors of biological molecules such as amino acids thus are considered prebiotic molecules in interstellar medium. In this study, we present chemical simulations of ethanimine with various physical conditions. From models for Sgr B2(N) and environs, calculated ethanimine abundances show reasonable agreement with observed values, while the translucent cloud models yield much lower abundances. These results agree with locations suggested by observations that ethanimine isomers were detected in the foreground of the shells of the hot core.

  20. Phase transition equilibrium of terthiophene isomers

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Jose C.S.; Lima, Carlos F.R.A.C.; Rocha, Marisa A.A. [Centro de Investigacao em Quimica, Departamento de Quimica e Bioquimica, Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal); Gomes, Ligia R. [CIAGEB, Faculdade de Ciencias de Saude Escola Superior de Saude da UFP, Universidade Fernando Pessoa, Rua Carlos da Maia, 296, P-4200-150 Porto (Portugal); REQUIMTE, Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal); Santos, Luis M.N.B.F., E-mail: lbsantos@fc.up.p [Centro de Investigacao em Quimica, Departamento de Quimica e Bioquimica, Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal)

    2011-02-15

    The thermodynamic study of the phase transition (fusion and sublimation) of 2,2':5',2''-terthiophene and 3,2':5',3''-terthiophene is presented. The obtained data is used to evaluate the (solid + liquid) and (solid + gas) phase equilibrium, and draw the phase diagrams of the pure compounds near the triple point coordinates. For each compound the vapour pressures at different temperatures were measured by a combined Knudsen effusion method with a vacuum quartz crystal microbalance. Based on the previous results, the standard molar enthalpies, entropies and Gibbs energies of sublimation were derived at T = 298.15 K. For the two terthiophenes and for 3,3'-bithiophene, the temperature, and the molar enthalpies of fusion were measured in a power compensated differential scanning calorimetry. The relationship between structure and energetics is discussed based on the experimental results, ab initio calculations and previous literature data for 2,2'-bithiophene and 3,3'-bithiophene. The 3,2':5',3''-terthiophene shows a higher solid phase stability than the 2,2':5',2''-terthiophene isomer arising from the higher cohesive energy due to positioning of the sulphur atom in the thiophene ring. The higher phase stability of 3,3'-bithiophene relative to 2,2'-bithiophene isomer is also related to its higher absolute entropy in the solid phase associated with the ring positional degeneracy observed in the crystal structure of this isomer. A significant differentiation in the crystal phase stability between isomers was found.

  1. A thirty second isomer in Hf-171

    NARCIS (Netherlands)

    Campbell, P; Billowes, J; Cochrane, ECA; Cooke, JL; Cooper, TG; Dendooven, P; Evans, DE; Grant, IS; Griffith, JAR; Honkanen, A; Huhta, M; Oinonen, M; Pearson, MR; Penttila, H; Persson, B.L.; Richardson, DS; Tungate, G; Wheeler, PD; Zybert, L; Aysto, J

    1997-01-01

    An isomer has been detected in Hf-171 with a half-life of T-1/2 = 29.5(9) s. The state was populated in the Yb-170(alpha,3n)Hf-171m reaction at a beam energy of E-alpha = 50 MeV in an on-line ion guide isotope separator. The isomeric Hf-17lm(+) beam was extracted from the ion guide, mass-analysed an

  2. Enantiomeric separation of tapentadol by capillary electrophoresis--study of chiral selectivity manipulation by various types of cyclodextrins.

    Science.gov (United States)

    Znaleziona, Joanna; Fejős, Ida; Ševčík, Juraj; Douša, Michal; Béni, Szabolcs; Maier, Vítězslav

    2015-02-01

    The chiral recognition of the centrally acting analgesic agent tapentadol and its isomers with various cyclodextrins (CDs) was studied by capillary electrophoresis, focusing on the migration order of four stereoisomers. In the case of non-charged hydroxypropylated CDs (2-hydroxypropyl-β-CD, 2-hydroxypropyl-γ-CD) the beta derivative was able to discriminate the S,R- and R,S-isomers in acidic background electrolyte, whereas the gamma allowed the separation of S,S- and R,R-tapentadol, respectively. Dual CD system containing both hosts was used to separate all of four isomers. Negatively charged sulfated-α-CD at 1.0% (w/v) concentration in 100mM sodium borate buffer (pH 9.5) was capable of separating the isomers with favorable enantiomer migration order and the optimized method was able to determine 0.15% of chiral impurities of tapentadol in the presence of the last migrating clinically important R,R-isomer.

  3. Conjugated linoleic acid isomers: differences in metabolism and biological effects.

    Science.gov (United States)

    Churruca, Itziar; Fernández-Quintela, Alfredo; Portillo, Maria Puy

    2009-01-01

    The term conjugated linoleic acid (CLA) refers to a mixture of linoleic acid positional and geometric isomers, characterized by having conjugated double bonds, not separated by a methylene group as in linoleic acid. CLA isomers appear as a minor component of the lipid fraction, found mainly in meat and dairy products from cows and sheep. The most abundant isomer is cis-9,trans-11, which represents up to 80% of total CLA in food. These isomers are metabolized in the body through different metabolic pathways, but important differences, that can have physiological consequences, are observed between the two main isomers. The trans-10,cis-12 isomer is more efficiently oxidized than the cis-9,trans-11 isomer, due to the position of its double bounds. Interest in CLA arose in its anticarcinogenic action but there is an increasing amount of specific scientific literature concerning the biological effects and properties of CLA. Numerous biological effects of CLA are due to the separate action of the most studied isomers, cis-9,trans-11 and trans-10,cis-12. It is also likely that some effects are induced and/or enhanced by these isomers acting synergistically. Although the cis-9,trans-11 isomer is mainly responsible for the anticarcinogenic effect, the trans-10,cis-12 isomer reduces body fat and it is referred as the most effective isomer affecting blood lipids. As far as insulin function is concerned, both isomers seem to be responsible for insulin resistance in humans. Finally, with regard to the immune system it is not clear whether individual isomers of CLA could act similarly or differently.

  4. Elucidating the Stereochemistry of Enzymatic Benzylsuccinate Synthesis with Chirally Labeled Toluene.

    Science.gov (United States)

    Seyhan, Deniz; Friedrich, Peter; Szaleniec, Maciej; Hilberg, Markus; Buckel, Wolfgang; Golding, Bernard T; Heider, Johann

    2016-09-12

    Benzylsuccinate synthase is a glycyl radical enzyme that initiates anaerobic toluene metabolism by adding fumarate to the methyl group of toluene to yield (R)-benzylsuccinate. To investigate whether the reaction occurs with retention or inversion of configuration at the methyl group of toluene, we synthesized both enantiomers of chiral toluene with all three H isotopes in their methyl groups. The chiral toluenes were converted into benzylsuccinates preferentially containing (2) H and (3) H at their benzylic C atoms, owing to a kinetic isotope effect favoring hydrogen abstraction from the methyl groups. The configuration of the products was analyzed by enzymatic CoA-thioester synthesis and stereospecific oxidation using enzymes involved in benzylsuccinate degradation. Assessment of the configurations of the benzylsuccinate isomers based on loss or retention of tritium showed that inversion of configuration at the methyl group occurs when the chiral toluenes react with fumarate.

  5. Syntheses and fully diastereospecific photochromic reactions of thiophenophan-1-enes with chiral bridges.

    Science.gov (United States)

    Jin-nouchi, Hirotsugu; Takeshita, Michinori

    2012-07-27

    Thiophenophan-1-enes with chiral polyether bridges were prepared and their diastereospecific photochromic reactions were studied. The coupling reaction of substituted dithienylethenes and various chiral synthons afforded thiophenophan-1-enes, namely, bridged dithienylethenes, as single enantiomers without optical resolution, thus indicating that these reactions occurred diastereoselectively. Upon UV irradiation, each optically active thiophenophan-1-ene isomerized to the corresponding enantiomer of the closed form and returned to the initial enantiomer of the open form upon visible irradiation. Because thiophenophan-1-enes never isomerized to other diastereomers even at a high temperature, they underwent diastereospecific photochromic reactions. Large changes were observed in the measurement of the optical rotations of the solutions of thiophenophan-1-enes at 588 nm according to their photochromic reactions. As there was no absorption at this wavelength for both isomers of each thiophenophan-1-enes, the nondestructive readout of the photochromic reaction could be carried out by using these chiral thiophenophan-1-enes.

  6. Astaxanthin alleviates oxidative stress insults-related derangements in human vascular endothelial cells exposed to glucose fluctuations.

    Science.gov (United States)

    Abdelzaher, Lobna A; Imaizumi, Takahiro; Suzuki, Tokiko; Tomita, Kengo; Takashina, Michinori; Hattori, Yuichi

    2016-04-01

    Glycemic fluctuations may play a critical role in the pathogenesis of diabetic complications, such as cardiovascular disease. We investigated whether the oxycarotenoid astaxanthin can reduce the detrimental effects of fluctuating glucose on vascular endothelial cells. Human umbilical venous endothelial cells were incubated for 3 days in media containing 5.5mM glucose, 22 mM glucose, or 5.5mM glucose alternating with 22 mM glucose in the absence or presence of astaxanthin or N-acetyl-L-cysteine (NAC). Constant high glucose increased reactive oxygen species (ROS) generation, but such an effect was more pronounced in fluctuating glucose. This was associated with up-regulated p22(phox) expression and down-regulated peroxisome proliferator activated receptor-γ coactivator (PGC-1α) expression. Astaxanthin inhibited ROS generation, p22(phox) up-regulation, and PGC-1α down-regulation by the stimuli of glucose fluctuation. Fluctuating glucose, but not constant high glucose, significantly decreased the endothelial nitric oxide synthase (eNOS) phosphorylation level at Ser-1177 without affecting total eNOS expression, which was prevented by astaxanthin as well as by the anti-oxidant NAC. Transferase-mediated dUTP nick end labeling (TUNEL) showed increased cell apoptosis in fluctuating glucose. Glucose fluctuation also resulted in up-regulating gene expression of pro-inflammatory mediators, interleukin-6 and intercellular adhesion molecule-1. These adverse changes were subdued by astaxanthin. The phosphorylation levels of c-Jun N-terminal kinase (JNK) and p38 were significantly increased by glucose fluctuations, and astaxanthin significantly inhibited the increase in JNK and p38 phosphorylation. Taken together, our results suggest that astaxanthin can protect vascular endothelial cells against glucose fluctuation by reducing ROS generation.

  7. Characterization of a novel South American population of the astaxanthin producing yeast Xanthophyllomyces dendrorhous (Phaffia rhodozyma).

    Science.gov (United States)

    Libkind, Diego; Moliné, Martín; de García, Virginia; Fontenla, Sonia; van Broock, María

    2008-03-01

    A novel population of the biotechnologically important yeast Xanthophyllomyces dendrorhous, the sexual stage of Phaffia rhodozyma, has been recently isolated for the first time in the southern Hemisphere (Patagonia, Argentina). The aim of the present work was to phenotypically and genotypically characterize two representative strains of this new population, and assess such strains as a potential biotechnological source of astaxanthin, fatty acids and extracellular enzymes. Minor variations were found in physiological tests. PCR fingerprinting studies (MSP-PCR) showed the main differences between X. dendrorhous Patagonian and Type strains. Patagonian strains accumulated a xanthophyll-like pigment, which was identified as astaxanthin. These strains showed low fatty acids content (mainly polyunsaturated fatty acids) and, of a total of six extracellular enzymes tested, only produced amylase. Genetic differences between Patagonian and collection X. dendrorhous strains could be explained by geographic isolation and habitat specificity.

  8. Interweaving Chiral Spirals

    CERN Document Server

    Kojo, Toru; Fukushima, Kenji; McLerran, Larry; Pisarski, Robert D

    2011-01-01

    We elaborate how to construct the interweaving chiral spirals in (2+1) dimensions, that is defined as a superposition of differently oriented chiral spirals. We divide the two-dimensional Fermi sea into distinct wedges characterized by the opening angle 2 Theta and the depth Q \\simeq pF, where pF is the Fermi momentum. Each wedge earns an energy gain by forming a single chiral spiral. The optimal values for Theta and Q are chosen by the balance between this energy gain and the energy costs from the deformed Fermi surface (dominant at large Theta) and patch-patch interactions (dominant at small Theta). We estimate these energy gains and costs by means of the expansions in terms of 1/Nc, Lambda_QCD/Q, and Theta using a non-local four-Fermi interaction model: At small 1/Nc the mass gap (chiral condensate) is large enough and the interaction among quarks and the condensate is local in momentum space thanks to the form factor in our non-local model. The fact that patch-patch interactions lie only near the patch bo...

  9. Simplicial chiral models

    CERN Document Server

    Rossi, P; Rossi, Paolo; Tan, Chung I

    1995-01-01

    Principal chiral models on a d-1 dimensional simplex are introduced and studied analytically in the large N limit. The d = 0 , 2, 4 and \\infty models are explicitly solved. Relationship with standard lattice models and with few-matrix systems in the double scaling limit are discussed.

  10. Crystal Structure of Chiral Acetato-bridged Binuclear Cyclopalladated complex[Pd(μ-O2CM3)(S-C6H4CHMeNH2)]2

    Institute of Scientific and Technical Information of China (English)

    杨帆; 李一平; 聂娟; 汤杰; 何鸣元

    2003-01-01

    Reaction of (S)-α-methylbenzylamine with Pd(OAc)2 in anhydrous HOAc produced the chiral complex[Pd(μ-O2CMe)(S-C6H4CHMeNH2)]2.(1).The complex was characterized by 1H NMR spectroscopy,elemental analysis and a single-crystal Xray analysis.The X-ray crystal structure analysis revealed that complex 1 has four isomers:two outer and two inner isomers.

  11. Chiral magnetic effect without chirality source in asymmetric Weyl semimetals

    CERN Document Server

    Kharzeev, Dmitri; Meyer, Rene

    2016-01-01

    We describe a new type of the Chiral Magnetic Effect (CME) that should occur in Weyl semimetals with an asymmetry in the dispersion relations of the left- and right-handed chiral Weyl fermions. In such materials, time-dependent pumping of electrons from a non-chiral external source generates a non-vanishing chiral chemical potential. This is due to the different capacities of the left- and right-handed (LH and RH) chiral Weyl cones arising from the difference in the density of states in the LH and RH cones. The chiral chemical potential then generates, via the chiral anomaly, a current along the direction of an applied magnetic field even in the absence of an external electric field. The source of chirality imbalance in this new setup is thus due to the band structure of the system and the presence of (non-chiral) electron source, and not due to the parallel electric and magnetic fields. We illustrate the effect by an argument based on the effective field theory, and by the chiral kinetic theory calculation f...

  12. "Glucose and ethanol-dependent transcriptional regulation of the astaxanthin biosynthesis pathway in Xanthophyllomyces dendrorhous"

    OpenAIRE

    Cifuentes Víctor; Baeza Marcelo; Alcaíno Jennifer; Lozano Carla; Wozniak Aniela; Niklitschek Mauricio; Marcoleta Andrés

    2011-01-01

    Abstract Background The yeast Xanthophyllomyces dendrorhous is one of the most promising and economically attractive natural sources of astaxanthin. The biosynthesis of this valuable carotenoid is a complex process for which the regulatory mechanisms remain mostly unknown. Several studies have shown a strong correlation between the carbon source present in the medium and the amount of pigments synthesized. Carotenoid production is especially low when high glucose concentrations are used in th...

  13. Genetic engineering of the complete carotenoid pathway towards enhanced astaxanthin formation in Xanthophyllomyces dendrorhous starting from a high-yield mutant.

    Science.gov (United States)

    Gassel, Sören; Breitenbach, Jürgen; Sandmann, Gerhard

    2014-01-01

    The yeast Xanthophyllomyces dendrorhous is one of the rare organisms which can synthesize the commercially interesting carotenoid astaxanthin. However, astaxanthin yield in wild-type and also in classical mutants is still too low for an attractive bioprocess. Therefore, we combined classical mutagenesis with genetic engineering of the complete pathway covering improved precursor supply for carotenogenesis, enhanced metabolite flow into the pathway, and efficient conversion of intermediates into the desired end product astaxanthin. We also constructed new transformation plasmids for the stepwise expression of the genes of 3-hydroxymethyl-3-glutaryl coenzyme A reductase, geranylgeranyl pyrophosphate synthase, phytoene synthase/lycopene cyclase, and astaxanthin synthase. Starting from two mutants with a 15-fold higher astaxanthin, we obtained transformants with an additional 6-fold increase in the final step of pathway engineering. Thus, a maximum astaxanthin content of almost 9 mg per g dry weight was reached in shaking cultures. Under optimized fermenter conditions, astaxanthin production with these engineered transformants should be comparable to Haematococcus pluvialis, the leading commercial producer of natural astaxanthin.

  14. Quantitative detection of astaxanthin and cantaxanthin in Atlantic salmon by resonance Raman spectroscopy

    Science.gov (United States)

    Ermakov, Igor V.; Ermakova, Maia R.; Gellermann, Werner

    2006-02-01

    Two major carotenoids species found in salmonids muscle tissues are astaxanthin and cantaxanthin. They are taken up from fish food and are responsible for the attractive red-orange color of salmon filet. Since carotenoids are powerful antioxidants and biomarkers of nutrient consumption, they are thought to indicate fish health and resistance to diseases in fish farm environments. Therefore, a rapid, accurate, quantitative optical technique for measuring carotenoid content in salmon tissues is of economic interest. We demonstrate the possibility of using fast, selective, quantitative detection of astaxanthin and cantaxanthin in salmon muscle tissues, employing resonance Raman spectroscopy. Analyzing strong Raman signals originating from the carbon-carbon double bond stretch vibrations of the carotenoid molecules under blue laser excitation, we are able to characterize quantitatively the concentrations of carotenoids in salmon muscle tissue. To validate the technique, we compared Raman data with absorption measurements of carotenoid extracts in acetone. A close correspondence was observed in absorption spectra for tissue extract in acetone and a pure astaxanthin solution. Raman results show a linear dependence between Raman and absorption data. The proposed technique holds promise as a method of rapid screening of carotenoid levels in fish muscle tissues and may be attractive for the fish farm industry to assess the dietary status of salmon, risk for infective diseases, and product quality control.

  15. Photoprotection vs. Photoinhibition of Photosystem II in Transplastomic Lettuce (Lactuca sativa) Dominantly Accumulating Astaxanthin.

    Science.gov (United States)

    Fujii, Ritsuko; Yamano, Nami; Hashimoto, Hideki; Misawa, Norihiko; Ifuku, Kentaro

    2016-07-01

    Transplastomic (chloroplast genome-modified; CGM) lettuce that dominantly accumulates astaxanthin grows similarly to a non-transgenic control with almost no accumulation of naturally occurring photosynthetic carotenoids. In this study, we evaluated the activity and assembly of PSII in CGM lettuce. The maximum quantum yield of PSII in CGM lettuce was lettuce showed a lower ability to induce non-photochemical quenching (NPQ) than the control under various light intensities. The fraction of slowly recovering NPQ in CGM lettuce, which is considered to be photoinhibitory quenching (qI), was less than half that of the control. In fact, (1)O2 generation was lower in CGM than in control leaves under high light intensity. CGM lettuce contained less PSII, accumulated mostly as a monomer in thylakoid membranes. The PSII monomers purified from the CGM thylakoids bound echinenone and canthaxanthin in addition to β-carotene, suggesting that a shortage of β-carotene and/or the binding of carbonyl carotenoids would interfere with the photophysical function as well as normal assembly of PSII. In contrast, high accumulation of astaxanthin and other carbonyl carotenoids was found within the thylakoid membranes. This finding would be associated with the suppression of photo-oxidative stress in the thylakoid membranes. Our observation suggests the importance of a specific balance between photoprotection and photoinhibition that can support normal photosynthesis in CGM lettuce producing astaxanthin.

  16. Detecting the chirality for coupled quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Cao Huijuan [Institute for Condensed Matter Physics, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510631 (China); Hu Lian [Institute for Condensed Matter Physics, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510631 (China)], E-mail: huliancaohj@yahoo.com

    2008-04-21

    We propose a scheme to detect the chirality for a system consisting of three coupled quantum dots. The chirality is found to be determined by the frequency of the transition between chiral states under the chiral symmetry broken perturbation. The results are important to construct quantum gates and to demonstrate chiral entangle states in the triangle spin dots.

  17. Influence of high-pressure homogenization, ultrasonication, and supercritical fluid on free astaxanthin extraction from β-glucanase-treated Phaffia rhodozyma cells.

    Science.gov (United States)

    Hasan, Mojeer; Azhar, Mohd; Nangia, Hina; Bhatt, Prakash Chandra; Panda, Bibhu Prasad

    2016-01-01

    In this study astaxanthin production by Phaffia rhodozyma was enhanced by chemical mutation using ethyl methane sulfonate. The mutant produces a higher amount of astaxanthin than the wild yeast strain. In comparison to supercritical fluid technique, high-pressure homogenization is better for extracting astaxanthin from yeast cells. Ultrasonication of dimethyl sulfoxide, hexane, and acetone-treated cells yielded less astaxanthin than β-glucanase enzyme-treated cells. The combination of ultrasonication with β-glucanase enzyme is found to be the most efficient method of extraction among all the tested physical and chemical extraction methods. It gives a maximum yield of 435.71 ± 6.55 µg free astaxanthin per gram of yeast cell mass.

  18. Methyl jasmonate- or gibberellins A3-induced astaxanthin accumulation is associated with up-regulation of transcription of beta-carotene ketolase genes (bkts) in microalga Haematococcus pluvialis.

    Science.gov (United States)

    Lu, Yandu; Jiang, Peng; Liu, Shaofang; Gan, Qinhua; Cui, Hongli; Qin, Song

    2010-08-01

    The microalga Haematococcus pluvialis accumulates astaxanthin in response to abiotic stresses. Since methyl jasmonate (MJ) and gibberellins A(3) (GA(3)) are involved in the stress responses of plants, the impact of these compounds on astaxanthin metabolism was studied. Alga cells treated separately with MJ and GA(3) accumulated more astaxanthin than the controls. MJ and GA(3) treatment increased the transcription of three beta-carotene ketolase genes (bkts). MJ- and GA(3)-responsive cis-acting elements were identified in the 5'-flanking regions of bkt genes. These results suggest that MJ and GA(3) constitute molecular signals in the network of astaxanthin accumulation. Induction of astaxanthin accumulation by MJ or GA(3) without any other stimuli presents an attractive application potential.

  19. Two-step cultivation for production of astaxanthin in Chlorella zofingiensis using a patented energy-free rotating floating photobioreactor (RFP).

    Science.gov (United States)

    Zhang, Zhao; Huang, Jim Junhui; Sun, Dongzhe; Lee, Yuankun; Chen, Feng

    2017-01-01

    In the present study, high light and nitrogen starvation with glucose-fed to the culture was found efficient to induce astaxanthin accumulation in Chlorella zofingiensis. Therefore, a two-step cultivation strategy including high biomass yield fermentation and outdoor induction with an energy-free RFP was conducted. During the fermentation, the highest cell density of 98.4gL(-1) and astaxanthin yield of 73.3mgL(-1) were achieved, which were higher than those so far reported in C. zofingiensis. During the outdoor induction, astaxanthin content was further increased by 1.5-fold leading to the highest astaxanthin productivity of 5.26mgL(-1)day(-1) under an optimal dilution of 5-fold. Our work thus provided an effective two-step cultivation strategy for production of astaxanthin by C. zofingiensis.

  20. Conversion of β-carotene into astaxanthin: Two separate enzymes or a bifunctional hydroxylase-ketolase protein?

    Directory of Open Access Journals (Sweden)

    Gudiña Eduardo

    2008-02-01

    Full Text Available Abstract Astaxanthin is a xanthophyll of great interest in animal nutrition and human health. The market prospect in the nutraceutics industries for this health-protective molecule is very promising. Astaxanthin is synthesized by several bacteria, algae and plants from β-carotene by the sequential action of two enzymes: a β-carotene, 3,3'-hydroxylase that introduces an hydroxyl group at the 3 (and 3' positions of each of the two β-ionone rings of β-carotene, and a β-carotene ketolase that introduces keto groups at carbons 4 and 4' of the β-ionone rings. Astaxanthin is also produced by the yeast-like basidiomycete Xanthophyllomyces dendrorhous. A gene crtS involved in the conversion of β-carotene to astaxanthin has been cloned simultaneously by two research groups. Complementation studies of X. dendrorhous mutants and expression analysis in Mucor circinelloides reveals that the CrtS enzyme is a β-carotene hydroxylase of the P-450 monooxygenase family that converts β-carotene to the hydroxylated derivatives β-cryptoxanthin and zeaxanthin, but it does not form astaxanthin or the ketolated intermediates in this fungus. A bifunctional β-carotene hydroxylase-ketolase activity has been proposed for the CrtS protein. The evidence for and against this hypothesis is analyzed in detail in this review.

  1. Effects of dietary supplementation with astaxanthin and β-carotene on the semen quality of goldfish (Carassius auratus).

    Science.gov (United States)

    Tizkar, B; Kazemi, R; Alipour, A; Seidavi, A; Naseralavi, G; Ponce-Palafox, J T

    2015-10-15

    This study was conducted to investigate the effects of two carotenoids (astaxanthin and β-carotene) on the sperm quality of goldfish Carassius auratus (Linnaeus, 1758). For this purpose, six diets containing concentrations of 50, 100, and 150 mg/kg of synthetic astaxanthin and β-carotene were added to a basic carp diet. One group of fish was also fed with a control diet (no added carotenoids). Osmolality, spermatocrit value, and sperm concentration significantly increased in the treatment supplemented with 150 mg/kg of astaxanthin (296.6 ± 1.1 mOsm/kg; 29.2 ± 0.6%; 17.2 ± 0.4 × 10(9) cells/mL, respectively) and β-carotene (295.2 ± 2.1 mOsm/kg; 32.5 ± 1.6%; 17.9 ± 0.5 × 10(9) cells/mL, respectively). The highest concentration of astaxanthin (10.4 ± 1.4 mg/kg) was recorded in the treatment of A150 (P astaxanthin improves osmolality, motility, fertilization rate, and sperm concentration.

  2. Enhanced autotrophic astaxanthin production from Haematococcus pluvialis under high temperature via heat stress-driven Haber-Weiss reaction.

    Science.gov (United States)

    Hong, Min-Eui; Hwang, Sung Kwan; Chang, Won Seok; Kim, Byung Woo; Lee, Jeewon; Sim, Sang Jun

    2015-06-01

    High temperatures (30-36 °C) inhibited astaxanthin accumulation in Haematococcus pluvialis under photoautotrophic conditions. The depression of carotenogenesis was primarily attributed to excess intracellular less reactive oxygen species (LROS; O2 (-) and H2O2) levels generated under high temperature conditions. Here, we show that the heat stress-driven inefficient astaxanthin production was improved by accelerating the iron-catalyzed Haber-Weiss reaction to convert LROS into more reactive oxygen species (MROS; O2 and OH·), thereby facilitating lipid peroxidation. As a result, during 18 days of photoautotrophic induction, the astaxanthin concentration of cells cultured in high temperatures in the presence of iron (450 μM) was dramatically increased by 75 % (30 °C) and 133 % (36 °C) compared to that of cells exposed to heat stress alone. The heat stress-driven Haber-Weiss reaction will be useful for economically producing astaxanthin by reducing energy cost and enhancing photoautotrophic astaxanthin production, particularly outdoors utilizing natural solar radiation including heat and light for photo-induction of H. pluvialis.

  3. Modeling of Xanthophyllomyces dendrorhous growth on glucose and overflow metabolism in batch and fed-batch cultures for astaxanthin production.

    Science.gov (United States)

    Liu, Yuan-Shuai; Wu, Jian-Yong

    2008-12-01

    An astaxanthin-producing yeast Xanthophyllomyces dendrorhous ENM5 was cultivated in a liquid medium containing 50 g/L glucose as the major carbon source in stirred fermentors (1.5-L working volume) in fully aerobic conditions. Ethanol was produced during the exponential growth phase as a result of overflow metabolism or fermentative catabolism of glucose by yeast cells. After accumulating to a peak of 3.5 g/L, the ethanol was consumed by yeast cells as a carbon source when glucose in the culture was nearly exhausted. High initial glucose concentrations and ethanol accumulation in the culture had inhibitory effects on cell growth. Astaxanthin production was partially associated with cell growth. Based on these culture characteristics, we constructed a modified Monod kinetic model incorporating substrate (glucose) and product (ethanol) inhibition to describe the relationship of cell growth rate with glucose and ethanol concentrations. This kinetic model, coupled with the Luedeking-Piret equation for the astaxanthin production, gave satisfactory prediction of the biomass production, glucose consumption, ethanol formation and consumption, and astaxanthin production in batch cultures over 25-75 g/L glucose concentration ranges. The model was also applied to fed-batch cultures to predict the optimum feeding scheme (feeding glucose and corn steep liquor) for astaxanthin production, leading to a high volumetric yield (28.6 mg/L) and a high productivity (5.36 mg/L/day).

  4. Astaxanthin, a Carotenoid, Stimulates Immune Responses by Enhancing IFN-γ and IL-2 Secretion in Primary Cultured Lymphocytes in Vitro and ex Vivo.

    Science.gov (United States)

    Lin, Kuan-Hung; Lin, Kao-Chang; Lu, Wan-Jung; Thomas, Philip-Aloysius; Jayakumar, Thanasekaran; Sheu, Joen-Rong

    2015-12-29

    Astaxanthin, a potent antioxidant carotenoid, plays a major role in modulating the immune response. In this study, we examined the immunomodulatory effects of astaxanthin on cytokine production in primary cultured lymphocytes both in vitro and ex vivo. Direct administration of astaxanthin (70-300 nM) did not produce cytotoxicity in lipopolysaccharide (LPS, 100 µg/ mL)- or concanavalin A (Con A, 10 µg/ mL)-activated lymphocytes, whereas astaxanthin alone at 300 nM induced proliferation of splenic lymphocytes (p astaxanthin, alone or with Con A, had no apparent effect on interferon (INF-γ) and interleukin (IL-2) production in primary cultured lymphocytes, it enhanced LPS-induced INF-γ production. In an ex vivo experiment, oral administration of astaxanthin (0.28, 1.4 and 7 mg/kg/day) for 14 days did not cause alterations in the body or spleen weights of mice and also was not toxic to lymphocyte cells derived from the mice. Moreover, treatment with astaxanthin significantly increased LPS-induced lymphocyte proliferation ex vivo but not Con A-stimulated lymphocyte proliferation ex vivo. Enzyme linked immunosorbent assay (ELISA) analysis revealed that administration of astaxanthin significantly enhanced INF-γ production in response to both LPS and Con A stimulation, whereas IL-2 production increased only in response to Con A stimulation. Also, astaxanthin treatment alone significantly increased IL-2 production in lymphocytes derived from mice, but did not significantly change production of INF-γ. These findings suggest that astaxanthin modulates lymphocytic immune responses in vitro, and that it partly exerts its ex vivo immunomodulatory effects by increasing INF-γ and IL-2 production without inducing cytotoxicity.

  5. Soldering Chiralities; 2, Non-Abelian Case

    CERN Document Server

    Wotzasek, C

    1996-01-01

    We study the non-abelian extension of the soldering process of two chiral WZW models of opposite chiralities, resulting in a (non-chiral) WZW model living in a 2D space-time with non trivial Riemanian curvature.

  6. The interstellar chemistry of H2C3O isomers

    Science.gov (United States)

    Loison, Jean-Christophe; Agúndez, Marcelino; Marcelino, Núria; Wakelam, Valentine; Hickson, Kevin M.; Cernicharo, José; Gerin, Maryvonne; Roueff, Evelyne; Guélin, Michel

    2016-01-01

    We present the detection of two H2C3O isomers, propynal and cyclopropenone, toward various starless cores and molecular clouds, together with upper limits for the third isomer propadienone. We review the processes controlling the abundances of H2C3O isomers in interstellar media showing that the reactions involved are gas-phase ones. We show that the abundances of these species are controlled by kinetic rather than thermodynamic effects. PMID:27013768

  7. Spiral Galaxies as Chiral Objects?

    CERN Document Server

    Capozziello, S; Capozziello, Salvatore; Lattanzi, Alessandra

    2005-01-01

    Spiral galaxies show axial symmetry and an intrinsic 2D-chirality. Environmental effects can influence the chirality of originally isolated stellar systems and a progressive loss of chirality can be recognised in the Hubble sequence. We point out a preferential modality for genetic galaxies as in microscopic systems like aminoacids, sugars or neutrinos. This feature could be the remnant of a primordial symmetry breaking characterizing systems at all scales.

  8. Chiral Biomarkers in Meteorites

    Science.gov (United States)

    Hoover, Richard B.

    2010-01-01

    The chirality of organic molecules with the asymmetric location of group radicals was discovered in 1848 by Louis Pasteur during his investigations of the rotation of the plane of polarization of light by crystals of sodium ammonium paratartrate. It is well established that the amino acids in proteins are exclusively Levorotary (L-aminos) and the sugars in DNA and RNA are Dextrorotary (D-sugars). This phenomenon of homochirality of biological polymers is a fundamental property of all life known on Earth. Furthermore, abiotic production mechanisms typically yield recemic mixtures (i.e. equal amounts of the two enantiomers). When amino acids were first detected in carbonaceous meteorites, it was concluded that they were racemates. This conclusion was taken as evidence that they were extraterrestrial and produced by abiologically. Subsequent studies by numerous researchers have revealed that many of the amino acids in carbonaceous meteorites exhibit a significant L-excess. The observed chirality is much greater than that produced by any currently known abiotic processes (e.g. Linearly polarized light from neutron stars; Circularly polarized ultraviolet light from faint stars; optically active quartz powders; inclusion polymerization in clay minerals; Vester-Ulbricht hypothesis of parity violations, etc.). This paper compares the measured chirality detected in the amino acids of carbonaceous meteorites with the effect of these diverse abiotic processes. IT is concluded that the levels observed are inconsistent with post-arrival biological contamination or with any of the currently known abiotic production mechanisms. However, they are consistent with ancient biological processes on the meteorite parent body. This paper will consider these chiral biomarkers in view of the detection of possible microfossils found in the Orgueil and Murchison carbonaceous meteorites. Energy dispersive x-ray spectroscopy (EDS) data obtained on these morphological biomarkers will be

  9. Free-standing chiral plasmonics

    Science.gov (United States)

    Leong, Eunice Sok Ping; Deng, Jie; Wu, Siji; Khoo, Eng Huat; Liu, Yan Jun

    2014-11-01

    Chiral plasmonic nanostructures offer the ability to achieve strong optical circular dichroism (CD) activity over a broad spectral range, which has been challenging for chiral molecules. Chiral plasmonic nanostructures have been extensively studied based on top-down and bottom-up fabrication techniques. Particularly, in the top-down electron-beam lithography, 3D plasmonic nanostructure fabrication involves layer-by-layer patterning and complex alignment, which is time-consuming and causes many defects in the structures. Here, we present a free-standing 3D chiral plamonic nanostructures using the electron-beam lithography technique with much simplified fabrication processes. The 3D chiral plasmonic nanostructures consist of a free-standing ultrathin silicon nitride membrane with well-aligned L-shape metal nanostructures on one side and disk-shape ones on the other side. The free-standing membrane provides an ultra-smooth metal/dielectric interface and uniformly defines the gap between the upper and lower layers in an array of chiral nanostructures. Such free-standing chiral plasmonic nanostructures exhibit strong CD at optical frequencies, which can be engineered by simply changing the disk size on one side of the membrane. Experimental results are in good agreement with the finite-difference time-domain simulations. Such free-standing chiral plasmonics holds great potential for chirality analysis of biomolecules, drugs, and chemicals.

  10. Chiral nuclear thermodynamics

    CERN Document Server

    Fiorilla, Salvatore; Weise, Wolfram

    2011-01-01

    We calculate the equation of state of nuclear matter for arbitrary isospin-asymmetry up to three loop order in the free energy density in the framework of in-medium chiral perturbation theory. In our approach 1\\pi- and 2\\pi-exchange dynamics with the inclusion of the \\Delta-isobar excitation as an explicit degree of freedom, corresponding to the long- and intermediate-range correlations, are treated explicitly. Few contact terms fixed to reproduce selected known properties of nuclear matter encode the short-distance physics. Two-body as well as three-body forces are systematically included. We find a critical temperature of about 15 MeV for symmetric nuclear matter. We investigate the dependence of the liquid-gas first-order phase transition on isospin-asymmetry. In the same chiral framework we calculate the chiral condensate of isospin-symmetric nuclear matter at finite temperatures. The contribution of the \\Delta-isobar excitation is essential for stabilizing the condensate. As a result, we find no indicati...

  11. Generalized simplicial chiral models

    CERN Document Server

    Alimohammadi, M

    2000-01-01

    Using the auxiliary field representation of the simplicial chiral models on a (d-1)-dimensional simplex, we generalize the simplicial chiral models by replacing the term Tr$(AA^{\\d})$ in the Lagrangian of these models, by an arbitrary class function of $AA^{\\d}; V(AA^{\\d})$. This is the same method that has been used in defining the generalized two-dimensional Yang-Mills theories (gYM_2) from ordinary YM_2. We call these models, the " generalized simplicial chiral models ". With the help of the results of one-link integral over a U(N) matrix, we compute the large-N saddle-point equations for eigenvalue density function $\\ro (z)$ in the weak ($\\b >\\b_c$) and strong ($\\b <\\b_c$) regions. In d=2, where the model somehow relates to gYM_2 theory, we solve the saddle-point equations and find $\\ro (z)$ in two region, and calculate the explicit value of critical point $\\b_c$ for $V(B)=TrB^n (B=AA^{\\d})$. For $V(B)=Tr B^2,Tr B^3$ and Tr$B^4$, we study the critical behaviour of the model at d=2, and by calculating t...

  12. Chemical stability of astaxanthin integrated into a food matrix: Effects of food processing and methods for preservation.

    Science.gov (United States)

    Martínez-Delgado, Alejandra Anahí; Khandual, Sanghamitra; Villanueva-Rodríguez, Socorro Josefina

    2017-06-15

    Astaxanthin is a carotenoid pigment found in numerous organisms ranging from bacteria to algae, yeasts, plants, crustaceans and fish such as salmon. Technological importance of this pigment emerged from various studies demonstrating that it is a powerful antioxidant, even with higher activity than alpha-tocopherol and other carotenoids. It has been included in various pharmaceutical products because of several beneficial properties. By its nature, astaxanthin is susceptible to degradation and can undergo chemical changes during food processing. Therefore, different studies have focused on improving the stability of the carotenoid under conditions such as high temperatures, pressures and mechanical force, among others. In this review, common processes involved in food processing and their effect on the stability of astaxanthin, integrated into a food matrix are discussed. Moreover, preservation techniques such as microencapsulation, inclusion in emulsions, suspensions, liposomes, etc., that are being employed to maintain stability of the product are also reviewed.

  13. Technical Report on the Development of Mutant Paracoccus strain and Optimization of Medium Composition for the Mass Production of Astaxanthin

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jong Il; Lee, Ju Woon; Kim, Jae Hun; Song, Beom Seok

    2010-08-15

    Astaxanthin is used to role of provitamin A, and it is stronger antioxidant activity than vitamin E (100-500 times higher activity) and other carotenoids (10-fold). Furthermore, astaxanthin is also used as a nutraceutical and a medicinal ingredient against degenerative diseases such as cancer, heart disease, and skin related illness. The objective of this study was develop a carotenoid-hyperproducing mutant of Paracoccus N81106 using gamma irradiation and optimized medium composition. A mutant of Paracoccus having higher carotenoid content was isolated, and the production medium was optimized using response surface methodology. These results support that astaxanthin with strong antioxidant activity could be economically produced using the mutant and will be helpful for the related industry

  14. Efficient Extraction of Astaxanthin from Phaffia rhodozyma with Polar and Non-polar Solvents after Acid Washing

    Institute of Scientific and Technical Information of China (English)

    YIN Chunhua; YANG Shuzhen; LIU Xiaolu; YAN Hai

    2013-01-01

    method of extracting astaxanthin from Phaffia rhodozyma with various solvents after acid washing was investigated.The extraction efficiency was distinctly increased after acid washing of P.rhodozyma cells.When the concentration of HCl was 0.4 mol·L-,the highest extraction efficiency of astaxanthin was achieved which was about three times higher than the control.Acetone or benzene as single polar or non-polar solvent was the most effective solvent in our research.With a combination of isopropanol and n-hexane (volume ratio of 2 ∶ 1),the maximal extraction efficiency was achieved,approximately 60% higher than that obtained with a single solvent.The liquid-solid ratio and the extracting time were also optimized.Under the optimum extraction conditions,the extraction yield of astaxanthin exceeded 98%.

  15. Separation and purification of astaxanthin from Phaffia rhodozyma by preparative high-speed counter-current chromatography.

    Science.gov (United States)

    Du, Xiping; Dong, Congcong; Wang, Kai; Jiang, Zedong; Chen, Yanhong; Yang, Yuanfan; Chen, Feng; Ni, Hui

    2016-09-01

    An effective high-speed counter-current chromatography (HSCCC) method was established for the preparative isolation and purification of astaxanthin from Phaffia rhodozyma. With a two-phase solvent system composed of n-hexane-acetone-ethanol-water (1:1:1:1, v/v/v/v), 100mg crude extract of P. rhodozyma was separated to yield 20.6mg of astaxanthin at 92.0% purity. By further one step silica gel column chromatography, the purity reached 99.0%. The chemical structure of astaxanthin was confirmed by thin layer chromatography (TLC), UV spectroscopy scanning, high performance liquid chromatography with a ZORBAX SB-C18 column and a Waters Nova-pak C18 column, and ESI/MS/MS.

  16. Astaxanthin hyperproduction by Phaffia rhodozyma (now Xanthophyllomyces dendrorhous) with raw coconut milk as sole source of energy.

    Science.gov (United States)

    Domíguez-Bocanegra, A R; Torres-Muñoz, J A

    2004-12-01

    Natural carbon sources, such as those present in cane sugar molasses and grape juice, promote the synthesis of astaxanthin in different Phaffia rhodozyma yeasts. One of these, coconut milk, has a very rich nutrient composition. The aim of this work was to investigate the utility of coconut milk as sole source of energy for astaxanthin pigment production by P. rhodozyma strains. Currently, coconut pulp is widely used in industrial processes in Mexico for the production of shampoos, candies, food, etc. However, coconut milk is a waste product. We show that coconut milk enhances astaxanthin production. The fermentation yielded 850 microg/g yeast with the NRRL-10921 wild-type strain and 1850 microg/g yeast with the mutated R1 strain. Production was better than reported results employing other natural carbon sources.

  17. Structures and Stability of NHS2 Isomers

    Institute of Scientific and Technical Information of China (English)

    池玉娟; 于海涛; 等

    2002-01-01

    Potential energy surface of HNS2 is investigated by means of second-order Moller-Plesset Perturbation theory(MP2) and QCISD(T) (single-point)methods,At final QCISD (T)/6-311++G(3df,2p)//MP2/6-311+G(d,p),level with zero-point vibrational energies included,cis-NHSS is found to be global minimum on the potential energy sufrace,followed by low-lying trans-HNSS ,HN(S)S(C2v).cis-HSNS,cis-NSSN,trans-HSNS,trans-NSSN,and HN(S)S(Cs) by 13.46,66.92,78.25,80.38,81.22,81.38 and 86.40 kJ/mol,respectively.A new high-lying HS(N)S isomer with Cs symmetry is located on the potential energy surface ,The kinetic stabilities of all isomers are predicted.Comprisons are made for HNS2 with its analogues,NHO2,HPS2 and HPO2,The causes that lead to the differences between HNS2 and its analogues are hypervalent capacity of phosphorus and distinct electronegativities of hydrogen,nitrogen and phosphorus.

  18. Structures and Stability of HNS2 Isomers

    Institute of Scientific and Technical Information of China (English)

    CHI,Yu-Juan(池玉娟); YU,Hai-Tao(于海涛); Fu,Hong-Gang(傅宏刚); HUANG,Xu-Ri(黄旭日); LI,Ze-Sheng(李泽生); SUN,Jia-Zhong(孙家钟)

    2002-01-01

    Potential energy surface of HNS2 is investigated by means of second-order Moller-Plesset perturbation theory (MP2) and QCISD(T) (single-point) methods. At final QCISD (T)/6-311++ G(3df,2p)//MP2/6-311++ G(d,p) level with zero-point vibrational energies included, cis-HNSS is found to be global minimum on the potential energy surface, followed by low-lying trans-HNSS, HN(S)S(C2v), cis-HSNS, cis-HSSN,rans-HSNS, trans-HSSN, and HN(S)S(Cs) by 13.46,66.92, 78.25, 80.38, 81.22, 81.38 and 86.40 kJ/mol, respectively. A new high-lying HS(N)S isomer with Cs symmetry is located on the potential energy surface. The kinetic stabilities of all isomers are predicted. Comparisons are made for HNS2 with its analogues, HNO2, HPS2 and HPO2. The causes that lead to the differences between HNS2 and its analogues are hypervalent capacity of phosphorus and distinct electronegativities of hydrogen, nitrogen and phosphorus.

  19. The effect of gamma irradiation on astaxanthin synthetase encoding gene in two mutant strains of Phaffia rhodozyma.

    Directory of Open Access Journals (Sweden)

    Naeimeh Najafi

    2013-09-01

    Full Text Available Astaxanthin, an orange-red carotenoid pigment, acts as a protective agent against oxidative damage to cells in vivo. The astaxanthin synthetase gene (crtS size consists of 3995 bp. This gene has been suggested to catalyse β-carotene to astaxanthin in Phaffia rhodozyma. The aim of this research was to find any possible changes in this gene in two mutant strains, Gam1 and Gam2 (with high astaxanthin pigment production, previously created by gamma irradiation.The astaxanthin synthetase gene sequence of Phaffia rhodozyma in the NCBI Gene bank was used to design primer. In Gam1, this gene was amplified using primers Asta F1, Asta R2, Asta F3, Asta R4. In Gam2, primers asta F1, asta R4 were used to amplify the gene. The amplified fragments were 8 sequenced using primers Asta F1, Asta R1, Asta F2, Asta R2, Asta F3, Asta R3 and Asta F4, Asta R4. Astaxanthin synthetase gene from two mutant strains, Gam1 and Gam2 were amplified using PCR. The amplified products were sequenced and aligned using the ClustalW software.The comparison of this gene showed 98% and 99% similarities between the reference sequence and Gam1 and Gam2 mutant strains, respectively, whereas the comparison of this gene in Gam1 and Gam2 mutant strains showed 97% similarity. However, the deduced proteins showed 78% and 83% between the reference protein obtained from the wild type and Gam1 and Gam2, respectively. This similarity was 75% between the mutant strains.

  20. Astaxanthin improves behavioral disorder and oxidative stress in prenatal valproic acid-induced mice model of autism.

    Science.gov (United States)

    Al-Amin, Md Mamun; Rahman, Md Mahbubur; Khan, Fazlur Rahman; Zaman, Fahmida; Mahmud Reza, Hasan

    2015-06-01

    Prenatal exposure to valproic acid on gestational day 12.5 may lead to the impaired behavior in the offspring, which is similar to the human autistic symptoms. To the contrary, astaxanthin shows neuroprotective effect by its antioxidant mechanism. We aimed to (i) develop mice model of autism and (ii) investigate the effect of astaxanthin on such model animals. Valproic acid (600 mg/kg) was administered intraperitoneally to the pregnant mice on gestational day 12.5. Prenatal valproic acid-exposed mice were divided into 2 groups on postnatal day 25 and astaxanthin (2mg/kg) was given to the experimental group (VPA_AST, n=10) while saline was given to the control group (VPA, n=10) for 4 weeks. Behavioral test including social interaction, open field and hot-plate were conducted on postnatal day 25 and oxidative stress markers such as lipid peroxidation, advanced protein oxidation product, nitric oxide, glutathione, and activity of superoxide dismutase and catalase were estimated on postnatal day 26 to confirm mice model of autism and on postnatal day 56 to assess the effect of astaxanthin. On postnatal day 25, prenatal valproic acid-exposed mice exhibited (i) delayed eye opening (ii) longer latency to respond painful stimuli, (iii) poor sociability and social novelty and (iv) high level of anxiety. In addition, an increased level of oxidative stress was found by determining different oxidative stress markers. Treatment with astaxanthin significantly (pAstaxanthin improves the impaired behavior in animal model of autism presumably by its antioxidant activity.

  1. Effects of homogenization process parameters on physicochemical properties of astaxanthin nanodispersions prepared using a solvent-diffusion technique

    Directory of Open Access Journals (Sweden)

    Anarjan N

    2015-02-01

    Full Text Available Navideh Anarjan,1 Hoda Jafarizadeh-Malmiri,2 Imededdine Arbi Nehdi,3 Hassen Mohamed Sbihi,3 Saud Ibrahim Al-Resayes,3 Chin Ping Tan4 1Young Researchers And Elite Club, Tabriz Branch, Islamic Azad University, Tabriz, Iran; 2Department of Chemical Engineering, Faculty of Food Engineering, Sahand University of Technology, Tabriz, Iran; 3King Saud University, College of Science, Chemistry Department, Riyadh, Saudi Arabia; 4Department of Food Technology, Faculty of Food Science and Technology, Universiti Putra Malaysia, Selangor, Malaysia Abstract: Nanodispersion systems allow incorporation of lipophilic bioactives, such as astaxanthin (a fat soluble carotenoid into aqueous systems, which can improve their solubility, bioavailability, and stability, and widen their uses in water-based pharmaceutical and food products. In this study, response surface methodology was used to investigate the influences of homogenization time (0.5–20 minutes and speed (1,000–9,000 rpm in the formation of astaxanthin nanodispersions via the solvent-diffusion process. The product was characterized for particle size and astaxanthin concentration using laser diffraction particle size analysis and high performance liquid chromatography, respectively. Relatively high determination coefficients (ranging from 0.896 to 0.969 were obtained for all suggested polynomial regression models. The overall optimal homogenization conditions were determined by multiple response optimization analysis to be 6,000 rpm for 7 minutes. In vitro cellular uptake of astaxanthin from the suggested individual and multiple optimized astaxanthin nanodispersions was also evaluated. The cellular uptake of astaxanthin was found to be considerably increased (by more than five times as it became incorporated into optimum nanodispersion systems. The lack of a significant difference between predicted and experimental values confirms the suitability of the regression equations connecting the response

  2. 虾青素生产方法研究进展%Research Progress of Astaxanthin's Production Process

    Institute of Scientific and Technical Information of China (English)

    肖素荣; 李京东

    2011-01-01

    虾青素作为一种具有特殊生理功效的物质,其抗氧化作用和着色作用在食品、药片、饲料以及化妆品行业有着广阔前景.本文主要论述了虾青素生产方法的研究进展.%Because of its special physiological function antioxidant ability and pigmentation ability, astaxanthin has broad prospects in food industries, medicine, feedstuffs as well as in cosmetics line. This thesis mainly discussed the research progress of astaxanthin's production process.

  3. Enantiomer Identification in Chiral Mixtures with Broadband Microwave Spectroscopy

    Science.gov (United States)

    Shubert, V. Alvin; Schmitz, David; Medcraft, Chris; Patterson, David; Doyle, John M.; Schnell, Melanie

    2014-06-01

    In nature and as products of chemical syntheses, chiral molecules often exist in mixtures with other chiral molecules. The analysis of these complex mixtures to identify the components, determine which enantiomers are present, and to measure the enantiomeric excesses (ee) is still one of the challenging but very important tasks of analytical chemistry. These analyses are required at every step of modern drug development, from candidate searches to production and regulation. We present here a new method of identifying individual enantiomers in mixtures of chiral molecules in the gas phase. It is based on broadband rotational spectroscopy and employs a sum or difference frequency generation three-wave mixing process that involves a closed cycle of three rotational transitions. The phase of the acquired signal bares the signature of the enantiomer (see figure), as it depends upon the combined quantity, μaμbμc, which is of opposite sign between members of an enantiomeric pair. Furthermore, because the signal amplitude is proportional to the ee, this technique allows for both determining which enantiomer is in excess and by how much. The high resolution of our technique allows us to perform molecule specific measurements of mixtures of chiral molecules with μaμbμc ≠ 0, even when the molecules are very similar (e.g. conformational isomers). We introduce the technique and present results on the analysis of mixtures of the terpenes, carvone, menthone, and carvomenthenol. D. Patterson, M. Schnell, J. M. Doyle, Nature. 497, 475-477, 2013 V. A. Shubert, D. Schmitz, D. Patterson, J. M. Doyle, M. Schnell, Ang. Chem. Int. Ed. 53, 1152-1155,2014

  4. Chiral nanophotonics chiral optical properties of plasmonic systems

    CERN Document Server

    Schäferling, Martin

    2017-01-01

    This book describes the physics behind the optical properties of plasmonic nanostructures focusing on chiral aspects. It explains in detail how the geometry determines chiral near-fields and how to tailor their shape and strength. Electromagnetic fields with strong optical chirality interact strongly with chiral molecules and, therefore, can be used for enhancing the sensitivity of chiroptical spectroscopy techniques. Besides a short review of the latest results in the field of plasmonically enhanced enantiomer discrimination, this book introduces the concept of chiral plasmonic near-field sources for enhanced chiroptical spectroscopy. The discussion of the fundamental properties of these light sources provides the theoretical basis for further optimizations and is of interest for researchers at the intersection of nano-optics, plasmonics and stereochemistry. .

  5. Isothermal Titration Calorimetry of Chiral Polymeric Nanoparticles.

    Science.gov (United States)

    Werber, Liora; Preiss, Laura C; Landfester, Katharina; Muñoz-Espí, Rafael; Mastai, Yitzhak

    2015-09-01

    Chiral polymeric nanoparticles are of prime importance, mainly due to their enantioselective potential, for many applications such as catalysis and chiral separation in chromatography. In this article we report on the preparation of chiral polymeric nanoparticles by miniemulsion polymerization. In addition, we describe the use of isothermal titration calorimetry (ITC) to measure the chiral interactions and the energetics of the adsorption of enantiomers from aqueous solutions onto chiral polymeric nanoparticles. The characterization of chirality in nano-systems is a very challenging task; here, we demonstrate that ITC can be used to accurately determine the thermodynamic parameters associated with the chiral interactions of nanoparticles. The use of ITC to measure the energetics of chiral interactions and recognition at the surfaces of chiral nanoparticles can be applied to other nanoscale chiral systems and can provide further insight into the chiral discrimination processes of nanomaterials.

  6. Astaxanthin inhibits JAK/STAT-3 signaling to abrogate cell proliferation, invasion and angiogenesis in a hamster model of oral cancer.

    Science.gov (United States)

    Kowshik, J; Baba, Abdul Basit; Giri, Hemant; Deepak Reddy, G; Dixit, Madhulika; Nagini, Siddavaram

    2014-01-01

    Identifying agents that inhibit STAT-3, a cytosolic transcription factor involved in the activation of various genes implicated in tumour progression is a promising strategy for cancer chemoprevention. In the present study, we investigated the effect of dietary astaxanthin on JAK-2/STAT-3 signaling in the 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis model by examining the mRNA and protein expression of JAK/STAT-3 and its target genes. Quantitative RT-PCR, immunoblotting and immunohistochemical analyses revealed that astaxanthin supplementation inhibits key events in JAK/STAT signaling especially STAT-3 phosphorylation and subsequent nuclear translocation of STAT-3. Furthermore, astaxanthin downregulated the expression of STAT-3 target genes involved in cell proliferation, invasion and angiogenesis, and reduced microvascular density, thereby preventing tumour progression. Molecular docking analysis confirmed inhibitory effects of astaxanthin on STAT signaling and angiogenesis. Cell culture experiments with the endothelial cell line ECV304 substantiated the role of astaxanthin in suppressing angiogenesis. Taken together, our data provide substantial evidence that dietary astaxanthin prevents the development and progression of HBP carcinomas through the inhibition of JAK-2/STAT-3 signaling and its downstream events. Thus, astaxanthin that functions as a potent inhibitor of tumour development and progression by targeting JAK/STAT signaling may be an ideal candidate for cancer chemoprevention.

  7. 雨生红球藻中虾青素的研究进展%Research of Astaxanthin in the Haematococcus pluvialis

    Institute of Scientific and Technical Information of China (English)

    赵晓燕; 朱海涛; 毕玉平; 王兴军

    2016-01-01

    Astaxanthin is a carotenoid and has numerous physiological functions and higher economic value. But the content of astaxanthin is less in nature and no more than 5%in Haematococcus pluvialis which is the best biogenetic source of astaxanthin. And because of the thicker cell wall , astaxanthin can not be extracted sufficiently which cause waste of part of astaxanthin. So how to fully extract astaxanthin has become a hot research topic. In this paper, physiological functions and extract methods of astaxanthin, cell disruption technologies of Haematococcus pluvialis will be discussed.%虾青素是一种具有众多生理功能的类胡萝卜素,经济价值极高,但是在自然界中含量较少,其最佳生物来源-雨生红球藻中含量也不超过5%,且该藻的细胞壁较厚,虾青素提取不充分,造成部分虾青素浪费。因此,如何充分提取雨生红球藻中的虾青素已成为研究热点。就虾青素的生理功能、提取方法、雨生红球藻的破壁方法展开论述。

  8. Cloning of the cytochrome p450 reductase (crtR gene and its involvement in the astaxanthin biosynthesis of Xanthophyllomyces dendrorhous

    Directory of Open Access Journals (Sweden)

    Sepúlveda Dionisia

    2008-10-01

    Full Text Available Abstract Background The yeast Xanthophyllomyces dendrorhous synthesizes astaxanthin, a carotenoid with high commercial interest. The proposed biosynthetic route in this organism is isopentenyl-pyrophosphate (IPP → geranyleranyl pyrophosphate (GGPP → phytoene → lycopene → β-carotene → astaxanthin. Recently, it has been published that the conversion of β-carotene into astaxanthin requires only one enzyme, astaxanthin synthase or CrtS, encoded by crtS gene. This enzyme belongs to the cytochrome P450 protein family. Results In this work, a crtR gene was isolated from X. dendrorhous yeast, which encodes a cytochrome P450 reductase (CPR that provides CrtS with the necessary electrons for substrate oxygenation. We determined the structural organization of the crtR gene and its location in the yeast electrophoretic karyotype. Two transformants, CBSTr and T13, were obtained by deleting the crtR gene and inserting a hygromycin B resistance cassette. The carotenoid composition of the transformants was altered in relation to the wild type strain. CBSTr forms yellow colonies because it is unable to produce astaxanthin, hence accumulating β-carotene. T13 forms pale colonies because its astaxanthin content is reduced and its β-carotene content is increased. Conclusion In addition to the crtS gene, X. dendrorhous requires a novel gene, crtR, for the conversion of β-carotene to astaxanthin.

  9. Chiral effects in adrenocorticolytic action of o,p'-DDD (mitotane) in human adrenal cells.

    Science.gov (United States)

    Asp, V; Cantillana, T; Bergman, A; Brandt, I

    2010-03-01

    Adrenocortical carcinoma (ACC) is a rare malignant disease with poor prognosis. The main pharmacological choice, o,p'-DDD (mitotane), produces severe adverse effects. Since o,p'-DDD is a chiral molecule and stereoisomers frequently possess different pharmacokinetic and/or pharmacodynamic properties, we isolated the two o,p'-DDD enantiomers, (R)-(+)-o,p'-DDD and (S)-(-)-o,p'-DDD, and determined their absolute structures. The effects of each enantiomer on cell viability and on cortisol and dehydroepiandrosterone (DHEA) secretion in the human adrenocortical cell line H295R were assessed. We also assayed the o,p'-DDD racemate and the m,p'- and p,p'-isomers. The results show small but statistically significant differences in activity of the o,p'-DDD enantiomers for all parameters tested. The three DDD isomers were equally potent in decreasing cell viability, but p,p'-DDD affected hormone secretion slightly less than the o,p'- and m,p'-isomers. The small chiral differences in direct effects on target cells alone do not warrant single enantiomer administration, but might reach importance in conjunction with possible stereochemical effects on pharmacokinetic processes in vivo.

  10. Chiral Dynamics 2006

    Science.gov (United States)

    Ahmed, Mohammad W.; Gao, Haiyan; Weller, Henry R.; Holstein, Barry

    2007-10-01

    pt. A. Plenary session. Opening remarks: experimental tests of chiral symmetry breaking / A. M. Bernstein. [Double pie symbols] scattering / H. Leutwyler. Chiral effective field theory in a [Triangle]-resonance region / V. Pascalutsa. Some recent developments in chiral perturbation theory / Ulf-G. Mei ner. Chiral extrapolation and nucleon structure from the lattice / R.D. Young. Recent results from HAPPEX / R. Michaels. Chiral symmetries and low energy searches for new physics / M.J. Ramsey-Musolf. Kaon physics: recent experimental progress / M. Moulson. Status of the Cabibbo angle / V. Cirigliano. Lattice QCD and nucleon spin structure / J.W. Negele. Spin sum rules and polarizabilities: results from Jefferson lab / J-P Chen. Compton scattering and nucleon polarisabilities / Judith A. McGovern. Virtual compton scattering at MIT-bates / R. Miskimen. Physics results from the BLAST detector at the BATES accelerator / R.P. Redwine. The [Pie sympbol]NN system, recent progress / C. Hanhart. Application of chiral nuclear forces to light nuclei / A. Nogga. New results on few-body experiments at low energy / Y. Nagai. Few-body lattice calculations / M.J. Savage. Research opportunities at the upgraded HI?S facility / H.R. Weller -- pt. B. Goldstone boson dynamics. Working group summary: Goldstone Boson dynamics / G. Colangelo and S. Giovannella. Recent results on radiative Kaon decays from NA48 and NA48/2 / S.G. López. Cusps in K-->3 [Pie symbol] decays / B. Kubis. Recent KTeV results on radiative Kaon decays / M.C. Ronquest. The [Double pie symbols] scattering amplitude / J.R. Peláez. Determination of the Regge parameters in the [Double pie symbols] scattering amplitude / I. Caprini. e+e- Hadronic cross section measurement at DA[symbol]NE with the KLOE detector / P. Beltrame. Measurement of the form factors of e+e- -->2([Pie symbol]+[Pie symbol]-), pp and the resonant parameters of the heavy charmonia at BES / H. Hu. Measurement of e+e- multihadronic cross section below 4

  11. Stereospecific Synthesis of the Geometrical Isomers of a Natural Product

    Science.gov (United States)

    Grove, T.; DiLella, D.; Volker, E.

    2006-01-01

    Stereospecific synthesis of a geometrical isomer is not a common topic for the introductory organic chemistry laboratory. We have developed and tested an experiment for the synthesis of (Z) and (E) isomers that has been performed successfully by undergraduate students. The experiment is presented to the students as a puzzle in which they must…

  12. Analysis of Heme oxygenase isomers in rat

    Institute of Scientific and Technical Information of China (English)

    Zhen-Wei Xia; Wen-Jun Cui; Xue-Hong Zhang; Qing-Xiang Shen; Jian Wang; Yun-Zhu Li; Shen-Nian Chen; Shan-Chang Yu

    2002-01-01

    AIM: To purify and identify heme oxygenase (HO) isomers which exist in rat liver, spleen and brain treated with hematin and phenylhydrazine and in untreated rat liver and to investigate the characteristics of HO isomers, to isolate and confirm the rat HO-1 cDNA that actually encodes HO-1 by expressing cDNA in monkey kidney cells (COS-1 cells), to prepare the rat heme oxygenase-1 (HO-1) mutant and to detect inhibition of HO-1 mutated enzyme.METHODS: First, rat liver, spleen and brain microsomal fi-actions were purified by DEAE-Sephacel and hydroxylapatite. The characteristics including activity, immunity and inducibility of two isomers (HO-1 and HO-2), and their apparent molecular weight were measured by detecting enzymatic activities, SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting analysis, respectively. Second, plasmid pcDNA3HO1 containing native rat HO-1 cDNA and pcDNA3HO1D25 carrying mutated rat HO-1 cDNA (His25Ala) were constructed by site-directed mutagenesis. COS-1 cells transfected with pcDNA3HO1 and pcDNA3HO1D25 were collected and disrupted by sonication, the microsomes were prepared by ultracentrifugation. Third, the inhibition of rat HO-1 mutant was analyzed.RESULTS: Two isomers were purified and identified in treated rat liver, spleen, brain and untreated rat liver. HO-1 was the predominant form with a ratio of 2.0:1 and 3.2:1 of HO-1 and HO-2 in liver and spleen, respectively, but only the activity of HO-2 in the brain and untreated liver could be detected. The apparent molecular weights of HO-1 and HO-2 were about Mr 30 000 and Mr 36 000 under reducing conditions, respectively. The antiserum against liver HO-2 was employed in Western blotting analysis, the reactivity of HO-1 in the liver was not observed. The plasmid pcDNA3HO1 was highly expressed in endoplasmic reticulum of transfected COS-1 cells. The specific activity was ≈5-fold higher than that of the control. However, the enzyme activity of mutated HO-1 declined. While

  13. The Structures and Stability of HNOS Isomers

    Institute of Scientific and Technical Information of China (English)

    CHI,Yu-Juan; YU,Hai-Tao; FU,Hong-Gang; XIN,Bai-Fu; LI,Ze-Sheng; SUN,Jia-Zhong

    2003-01-01

    Potential energy surface of HNOS system is investigated by means ofMP2 method with 6-311 ++ G(d, p)basis set. The energyfor each minimum and saddle point on the potential energy surface is corrected at the QCISD(T)/6-311 ++ G(3df, 2p) level of theory with zero-point vibrational energy included. As a result, eighteen isoners are theoretically predicted and cis-HNSO is found to be global minimum on the potential energy surface. Wherein, fourteen isoners are considered as kinetically stable species, and should be experimentally observed. Comparisons are made for HNOS system with its analogues, HNO2 and HNS2. The nature of bonding and isomers' stability of HNOS system are similar to HNS2. The obvious similarities and discrepancies among HNOS, HNO2 and HNS2are attributed to the hypervalent capacity of sulfur, oxygen and nitrogen atoms.

  14. Dileptons and Chiral Symmetry Restoration

    CERN Document Server

    Hohler, P M

    2015-01-01

    We report on recent work relating the medium effects observed in dilepton spectra in heavy-ion collisions to potential signals of chiral symmetry restoration. The key connection remains the approach to spectral function degeneracy between the vector-isovector channel with its chiral partner, the axialvector-isovector channel. Several approaches are discussed to elaborate this connection, namely QCD and Weinberg sum rules with input for chiral order parameters from lattice QCD, and chiral hadronic theory to directly evaluate the medium effects of the axialvector channel and the pertinent pion decay constant as function of temperature. A pattern emerges where the chiral mass splitting between rho and a_1 burns off and is accompanied by a strong broadening of the spectral distributions.

  15. Applications Of Chiral Perturbation Theory

    CERN Document Server

    Mohta, V

    2005-01-01

    Effective field theory techniques are used to describe the spectrum and interactions of hadrons. The mathematics of classical field theory and perturbative quantum field theory are reviewed. The physics of effective field theory and, in particular, of chiral perturbation theory and heavy baryon chiral perturbation theory are also reviewed. The geometry underlying heavy baryon chiral perturbation theory is described in detail. Results by Coleman et. al. in the physics literature are stated precisely and proven. A chiral perturbation theory is developed for a multiplet containing the recently- observed exotic baryons. A small coupling expansion is identified that allows the calculation of self-energy corrections to the exotic baryon masses. Opportunities in lattice calculations are discussed. Chiral perturbation theory is used to study the possibility of two multiplets of exotic baryons mixed by quark masses. A new symmetry constraint on reduced partial widths is identified. Predictions in the literature based ...

  16. Quark structure of chiral solitons

    CERN Document Server

    Diakonov, D

    2004-01-01

    There is a prejudice that the chiral soliton model of baryons is something orthogonal to the good old constituent quark models. In fact, it is the opposite: the spontaneous chiral symmetry breaking in strong interactions explains the appearance of massive constituent quarks of small size thus justifying the constituent quark models, in the first place. Chiral symmetry ensures that constituent quarks interact very strongly with the pseudoscalar fields. The ``chiral soliton'' is another word for the chiral field binding constituent quarks. We show how the old SU(6) quark wave functions follow from the ``soliton'', however, with computable relativistic corrections and additional quark-antiquark pairs. We also find the 5-quark wave function of the exotic baryon Theta+.

  17. Mechanism of radical cation formation from the excited states of zeaxanthin and astaxanthin in chloroform.

    Science.gov (United States)

    Han, Rui-Min; Tian, Yu-Xi; Wu, Yi-Shi; Wang, Peng; Ai, Xi-Cheng; Zhang, Jian-Ping; Skibsted, Leif H

    2006-01-01

    The C-40 xanthophylls zeaxanthin and astaxanthin were confirmed to form radical cations, Car.+, in the electron-accepting solvent chloroform by direct excitation using subpicosecond time-resolved absorption spectroscopy in combination with spectroelectrochemical determination of the near-infrared absorption of Car.+. For the singlets, the S2(1B(u+) state and most likely the S(x)(3A(g)-) state directly eject electrons to chloroform leading to the rapid formation of Car.+ on a timescale of approximately 100 fs; the lowest-lying S1(2A(g)-) state, however, remains inactive. Standard reduction potential for Car.+ was determined by cyclic voltametry to have the value 0.63 V for zeaxanthin and 0.75 V for astaxanthin from which excited state potentials were calculated, which confirmed the reactivity toward radical cation formation. On the other hand, Car.+ formation from the lowest triplet excited state T1 populated through anthracene sensitization is mediated by a precursor suggested to be a solute-solvent complex detected with broad near-infrared absorption to the shorter wavelength side of the characteristic Car.+ absorption. However, ground state carotenoids are able to react with a secondary solvent radical to yield Car.+, a process occurring within 16 micros for zeaxanthin and within 21 mus for astaxanthin. Among the two xanthophylls together with lycopene and beta-carotene, all having 11 conjugated double bonds, zeaxanthin ranks with the highest reactivity in forming Car.+ from either the S2(1B(u+)) or the ground state. The effects of substituent groups on the reactivity are discussed.

  18. Observing Disoriented Chiral Condensates

    CERN Document Server

    Bjorken, James D; Taylor, C C

    1993-01-01

    We speculate that, in very high energy hadronic collisions, large fireballs may be produced with interiors which have anomalous chiral order parameters. Such a process would result in radiation of pions with distinctive momentum and isospin distributions, and may provide an explanation of Centauro and related phenomena in cosmic-ray events. The phenomenology of such events is reviewed, with emphasis on the possibility of observing such phenomena at Fermilab experiment T-864 (MiniMax), or at a Full Acceptance Detector (FAD) at the SSC.

  19. Chiral Nuclear Dynamics II

    CERN Document Server

    Rho, Mannque

    2008-01-01

    This is the sequel to the first volume to treat in one effective field theory framework the physics of strongly interacting matter under extreme conditions. This is vital for understanding the high temperature phenomena taking place in relativistic heavy ion collisions and in the early Universe, as well as the high-density matter predicted to be present in compact stars. The underlying thesis is that what governs hadronic properties in a heat bath and/or a dense medium is hidden local symmetry which emerges from chiral dynamics of light quark systems and from the duality between QCD in 4D and

  20. Quality evaluation of terpinen-4-ol-type Australian tea tree oils and commercial products: an integrated approach using conventional and chiral GC/MS combined with chemometrics.

    Science.gov (United States)

    Wang, Mei; Zhao, Jianping; Avula, Bharathi; Wang, Yan-Hong; Chittiboyina, Amar G; Parcher, Jon F; Khan, Ikhlas A

    2015-03-18

    GC/MS, chiral GC/MS, and chemometric techniques were used to evaluate a large set (n=104) of tea tree oils (TTO) and commercial products purported to contain TTO. Twenty terpenoids were determined in each sample and compared with the standards specified by ISO-4730-2004. Several of the oil samples that were ISO compliant when distilled did not meet the ISO standards in this study primarily due to the presence of excessive p-cymene and/or depletion of terpinenes. Forty-nine percent of the commercial products did not meet the ISO specifications. Four terpenes, viz., α-pinene, limonene, terpinen-4-ol, and α-terpineol, present in TTOs with the (+)-isomer predominant were measured by chiral GC/MS. The results clearly indicated that 28 commercial products contained excessive (+)-isomer or contained the (+)-isomer in concentrations below the norm. Of the 28 outliers, 7 met the ISO standards. There was a substantial subset of commercial products that met ISO standards but displayed unusual enantiomeric+/-ratios. A class predictive model based on the oils that met ISO standards was constructed. The outliers identified by the class predictive model coincided with the samples that displayed an abnormal chiral ratio. Thus, chiral and chemometric analyses could be used to confirm the identification of abnormal commercial products including those that met all of the ISO standards.

  1. Classification of Astaxanthin Colouration of Salmonid Fish using Spectral Imaging and Tricolour Measurement

    DEFF Research Database (Denmark)

    Ljungqvist, Martin Georg; Dissing, Bjørn Skovlund; Nielsen, Michael Engelbrecht

    The goal of this study was to investigate if it is possible to differentiate between rainbow trout (Oncorhynchus mykiss) having been fed with natural or synthetic astaxanthin. Three different techniques were used for visual inspection of the surface colour of the fish meat: multi-spectral image...... capturing, tricolour CIELAB measurement, and manual SalmoFan inspection. Furthermore it was tested whether the best predictions come from measurements of the steak or the fillet of the fish. Methods used for classication were linear discriminant analysis (LDA), quadratic discriminant analysis (QDA......), and sparse linear discriminant analysis (SLDA)....

  2. Studies of astaxanthin biosynthesis in Xanthophyllomyces dendrorhous (Phaffia rhodozyma). Effect of inhibitors and low temperature.

    Science.gov (United States)

    Ducrey Sanpietro, L M; Kula, M R

    1998-08-01

    The effect of nicotine and diphenylamine on astaxanthin biosynthesis in Xanthophyllomyces dendrorhous was studied. The effects were analysed under standard and low temperature conditions. It was found that 10 mM-nicotine inhibits the cyclization of lycopene and de novo protein synthesis was not needed to reverse the inhibition. The oxidation of beta-carotene was irreversibly inhibited by 10 microM-diphenylamine while the dehydrogenation of phytoene was reversibly inhibited by 60 microM-diphenylamine. The simultaneous exposure to low temperature (4 degrees C) overcomes the inhibition of beta-carotene oxidation at low diphenylamine concentration.

  3. Development and Application of Astaxanthin%虾青素的开发与应用

    Institute of Scientific and Technical Information of China (English)

    王进波

    2000-01-01

    @@ 虾青素(astaxanthin),又名虾黄质、龙虾壳色素,其化学名称为3,3'-二羟基-β,β-胡萝卜素-4,4'-二酮,分子式为C40H52O4.它广泛存在于生物界中,特别是水产动物的虾、蟹、鱼和鸟类的羽毛中.

  4. PBPK modeling of the cis- and trans-permethrin isomers and their major urinary metabolites in rats.

    Science.gov (United States)

    Willemin, Marie-Emilie; Desmots, Sophie; Le Grand, Rozenn; Lestremau, François; Zeman, Florence A; Leclerc, Eric; Moesch, Christian; Brochot, Céline

    2016-03-01

    Permethrin, a pyrethroid insecticide, is suspected to induce neuronal and hormonal disturbances in humans. The widespread exposure of the populations has been confirmed by the detection of the urinary metabolites of permethrin in biomonitoring studies. Permethrin is a chiral molecule presenting two forms, the cis and the trans isomers. Because in vitro studies indicated a metabolic interaction between the trans and cis isomers of permethrin, we adapted and calibrated a PBPK model for trans- and cis-permethrin separately in rats. The model also describes the toxicokinetics of three urinary metabolites, cis- and trans-3-(2,2 dichlorovinyl)-2,2-dimethyl-(1-cyclopropane) carboxylic acid (cis- and trans-DCCA), 3-phenoxybenzoic acid (3-PBA) and 4'OH-phenoxybenzoic acid (4'-OH-PBA). In vivo experiments performed in Sprague-Dawley rats were used to calibrate the PBPK model in a Bayesian framework. The model captured well the toxicokinetics of permethrin isomers and their metabolites including the rapid absorption, the accumulation in fat, the extensive metabolism of the parent compounds, and the rapid elimination of metabolites in urine. Average hepatic clearances in rats were estimated to be 2.4 and 5.7 L/h/kg for cis- and trans-permethrin, respectively. High concentrations of the metabolite 4'-OH-PBA were measured in urine compared to cis- and trans-DCCA and 3-PBA. The confidence in the extended PBPK model was then confirmed by good predictions of published experimental data obtained using the isomers mixture. The extended PBPK model could be extrapolated to humans to predict the internal dose of exposure to permethrin from biomonitoring data in urine.

  5. Spontaneous Chiral Symmetry Breaking as Condensation of Dynamical Chirality

    CERN Document Server

    Alexandru, Andrei

    2012-01-01

    The occurrence of spontaneous chiral symmetry breaking (SChSB) is equivalent to sufficient abundance of Dirac near-zeromodes. However, dynamical mechanism leading to breakdown of chiral symmetry should be naturally reflected in chiral properties of the modes. Here we offer such connection, presenting evidence that SChSB in QCD proceeds via the appearance of modes exhibiting dynamical tendency for local chiral polarization. These modes form a band of finite width Lambda_ch (chiral polarization scale) around the surface of otherwise anti--polarized Dirac sea, and condense. Lambda_ch characterizes the dynamics of the breaking phenomenon and can be converted to a quark mass scale, thus offering conceptual means to determine which quarks of nature are governed by broken chiral dynamics. It is proposed that, within the context of SU(3) gauge theories with fundamental Dirac quarks, mode condensation is equivalent to chiral polarization, making Lambda_ch an "order parameter" of SChSB. Several uses of these features, ...

  6. Repulsive Casimir Force in Chiral Metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, R.; Zhou, J.; Koschny, Th.; Economou, E.N.; Soukoulis, C.M.

    2009-09-04

    We demonstrate theoretically that one can obtain repulsive Casimir forces and stable nanolevitations by using chiral metamaterials. By extending the Lifshitz theory to treat chiral metamaterials, we find that a repulsive force and a minimum of the interaction energy possibly exist for strong chirality, under realistic frequency dependencies and correct limiting values (for zero and infinite frequencies) of the permittivity, permeability, and chiral coefficients.

  7. Repulsive Casimir Force in Chiral Metamaterials

    OpenAIRE

    Zhao, R.; J. Zhou; Koschny, Th.; Economou, E. N.; C M Soukoulis

    2009-01-01

    We demonstrate theoretically that one can obtain repulsive Casimir forces and stable nanolevitations by using chiral metamaterials. By extending the Lifshitz theory to treat chiral metamaterials, we find that a repulsive force and a minimum of the interaction energy exist for strong chirality, under realistic frequency dependencies and correct limiting values (for zero and infinite frequencies) of the permittivity, permeability, and chiral coefficients.

  8. Repulsive Casimir Force in Chiral Metamaterials

    Science.gov (United States)

    Zhao, R.; Zhou, J.; Koschny, Th.; Economou, E. N.; Soukoulis, C. M.

    2009-09-01

    We demonstrate theoretically that one can obtain repulsive Casimir forces and stable nanolevitations by using chiral metamaterials. By extending the Lifshitz theory to treat chiral metamaterials, we find that a repulsive force and a minimum of the interaction energy possibly exist for strong chirality, under realistic frequency dependencies and correct limiting values (for zero and infinite frequencies) of the permittivity, permeability, and chiral coefficients.

  9. Nanoscale chirality in metal and semiconductor nanoparticles.

    Science.gov (United States)

    Kumar, Jatish; Thomas, K George; Liz-Marzán, Luis M

    2016-10-18

    The field of chirality has recently seen a rejuvenation due to the observation of chirality in inorganic nanomaterials. The advancements in understanding the origin of nanoscale chirality and the potential applications of chiroptical nanomaterials in the areas of optics, catalysis and biosensing, among others, have opened up new avenues toward new concepts and design of novel materials. In this article, we review the concept of nanoscale chirality in metal nanoclusters and semiconductor quantum dots, then focus on recent experimental and theoretical advances in chiral metal nanoparticles and plasmonic chirality. Selected examples of potential applications and an outlook on the research on chiral nanomaterials are additionally provided.

  10. Nonequilibrium chiral perturbation theory and disoriented chiral condensates

    CERN Document Server

    Nicola, A G

    1999-01-01

    We analyse the extension of Chiral Perturbation Theory to describe a meson gas out of thermal equilibrium. For that purpose, we let the pion decay constant be a time-dependent function and work within the Schwinger-Keldysh contour technique. A useful connection with curved space-time QFT allows to consistently renormalise the model, introducing two new low-energy constants in the chiral limit. We discuss the applicability of our approach within a Relativistic Heavy-Ion Collision environment. In particular, we investigate the formation of Disoriented Chiral Condensate domains in this model, via the parametric resonance mechanism.

  11. Chiral quantum optics.

    Science.gov (United States)

    Lodahl, Peter; Mahmoodian, Sahand; Stobbe, Søren; Rauschenbeutel, Arno; Schneeweiss, Philipp; Volz, Jürgen; Pichler, Hannes; Zoller, Peter

    2017-01-25

    Advanced photonic nanostructures are currently revolutionizing the optics and photonics that underpin applications ranging from light technology to quantum-information processing. The strong light confinement in these structures can lock the local polarization of the light to its propagation direction, leading to propagation-direction-dependent emission, scattering and absorption of photons by quantum emitters. The possibility of such a propagation-direction-dependent, or chiral, light-matter interaction is not accounted for in standard quantum optics and its recent discovery brought about the research field of chiral quantum optics. The latter offers fundamentally new functionalities and applications: it enables the assembly of non-reciprocal single-photon devices that can be operated in a quantum superposition of two or more of their operational states and the realization of deterministic spin-photon interfaces. Moreover, engineered directional photonic reservoirs could lead to the development of complex quantum networks that, for example, could simulate novel classes of quantum many-body systems.

  12. Chiral imbalance in QCD

    Directory of Open Access Journals (Sweden)

    Andrianov Alexander

    2017-01-01

    Full Text Available The chiral imbalance (ChI is given by a difference between the numbers of RH and LH quarks which may occur in the fireball after heavy ion collision. To characterize it adiabatically a quark chiral (axial chemical potential must be introduced taking into account emergence of a ChI in such a phase. In this report the phenomenology of formation of Local spatial Parity Breaking (LPB in the hot and dense baryon matter is discussed and its simulation within a number of QCD-inspired models is outlined. The appearance of new states in the spectra of scalar, pseudoscalar and vector particles in such a matter is elucidated. In particular, from the effective vector meson theory in the presence of Chern-Simons interaction it is demonstrated that the spectrum of massive vector mesons splits into three polarization components with different effective masses. The asymmetry in production of longitudinally and transversely polarized states of ρ and ω mesons for various values of the dilepton invariant mass can serve as a characteristic indication of the LPB in PHENIX, STAR and ALICE experiments.

  13. Chirally extended quantum chromodynamics

    CERN Document Server

    Brower, R C; Tan, C I; Richard C Brower; Yue Shen; Chung-I Tan

    1994-01-01

    We propose an extended Quantum Chromodynamics (XQCD) Lagrangian in which the fermions are coupled to elementary scalar %\\sigma and \\pi fields through a Yukawa coupling which preserves chiral invariance. Our principle motivation is to find a new lattice formulation for QCD which avoids the source of critical slowing down usually encountered as the bare quark mass is tuned to the chiral limit. The phase diagram and the weak coupling limit for XQCD are studied. They suggest a conjecture that the continuum limit of XQCD is the same as the continuum limit of conventional lattice formulation of QCD. As examples of such universality, we present the large N solutions of two prototype models for XQCD, in which the mass of the spurious pion and sigma resonance go to infinity with the cut-off. Even if the universality conjecture turns out to be false, we believe that XQCD will still be useful as a low energy effective action for QCD phenomenology on the lattice. Numerical simulations are recommended to further investiga...

  14. Astaxanthin Attenuates the Apoptosis of Retinal Ganglion Cells in db/db Mice by Inhibition of Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Xiao-Li Kang

    2013-03-01

    Full Text Available Diabetic retinopathy is a common diabetic eye disease caused by changes in retinal ganglion cells (RGCs. It is an ocular manifestation of systemic disease, which affects up to 80% of all patients who have had diabetes for 10 years or more. The genetically diabetic db/db mouse, as a model of type-2 diabetes, shows diabetic retinopathy induced by apoptosis of RGCs. Astaxanthin is a carotenoid with powerful antioxidant properties that exists naturally in various plants, algae and seafood. Here, astaxanthin was shown to reduce the apoptosis of RGCs and improve the levels of oxidative stress markers, including superoxide anion, malondialdehyde (MDA, a marker of lipid peroxidation, 8-hydroxy-2-deoxyguanosine (8-OHdG, indicator of oxidative DNA damage and MnSOD (manganese superoxide dismutase activity in the retinal tissue of db/db mouse. In addition, astaxanthin attenuated hydrogen peroxide(H2O2-induced apoptosis in the transformed rat retinal ganglion cell line RGC-5. Therefore, astaxanthin may be developed as an antioxidant drug to treat diabetic retinopathy.

  15. Differential expression of carotenogenic genes, associated changes on astaxanthin production and photosynthesis features induced by JA in H. pluvialis.

    Directory of Open Access Journals (Sweden)

    Zhengquan Gao

    Full Text Available Haematococcus pluvialis is an organism that under certain conditions can produce astaxanthin, an economically important carotenoid. In this study, the transcriptional expression patterns of eight carotenogenic genes of H. pluvialis in response to jasmonic acid (JA were evaluated using real-time PCR. Astaxanthin accumulation action and photosynthesis flourescence were monitored at the same time. The results showed all eight genes exhibited higher transcriptional expression significantly under JA treatments. JA25 (25 mg/L induction had greater effect (>10-fold up-regulation on the transcriptional expression of pds, crtR-B and lyc than on ipi-1, ipi-2, psy, bkt2, and crtO. JA50 (50 mg/L treatment had greater impact on the transcriptional expression of ipi-1, ipi-2, psy, crtR-B and crtO than on pds, lyc and bkt2. Astaxanthin biosynthesis in the presence of JA appeared to be up-regulated mainly by psy, pds, crtR-B, lyc, bkt2 and crtO at the transcriptional level and ipi-1, ipi-2 at both transcriptional and post-transcriptional levels. Under JA induction, the photosynthetic efficiency [Y (II] and the maximum quantum efficiency of PS II (Fv/Fm decreased significantly, but the non-photochemical quenching of chlorophyll fluorescence (NPQ increased drastically with the accumulation of astaxanthin.

  16. Accumulation of Astaxanthin by a New Haematococcus pluvialis Strain BM1 from the White Sea Coastal Rocks (Russia

    Directory of Open Access Journals (Sweden)

    Konstantin Chekanov

    2014-08-01

    Full Text Available We report on a novel arctic strain BM1 of a carotenogenic chlorophyte from a coastal habitat with harsh environmental conditions (wide variations in solar irradiance, temperature, salinity and nutrient availability identified as Haematococcus pluvialis Flotow. Increased (25‰ salinity exerted no adverse effect on the growth of the green BM1 cells. Under stressful conditions (high light, nitrogen and phosphorus deprivation, green vegetative cells of H. pluvialis BM1 grown in BG11 medium formed non-motile palmelloid cells and, eventually, hematocysts capable of a massive accumulation of the keto-carotenoid astaxanthin with a high nutraceutical and therapeutic potential. Routinely, astaxanthin was accumulated at the level of 4% of the cell dry weight (DW, reaching, under prolonged stress, 5.5% DW. Astaxanthin was predominantly accumulated in the form of mono- and diesters of fatty acids from C16 and C18 families. The palmelloids and hematocysts were characterized by the formation of red-colored cytoplasmic lipid droplets, increasingly large in size and number. The lipid droplets tended to merge and occupied almost the entire volume of the cell at the advanced stages of stress-induced carotenogenesis. The potential application of the new strain for the production of astaxanthin is discussed in comparison with the H. pluvialis strains currently employed in microalgal biotechnology.

  17. Accumulation of astaxanthin by a new Haematococcus pluvialis strain BM1 from the white sea coastal rocks (Russia).

    Science.gov (United States)

    Chekanov, Konstantin; Lobakova, Elena; Selyakh, Irina; Semenova, Larisa; Sidorov, Roman; Solovchenko, Alexei

    2014-08-15

    We report on a novel arctic strain BM1 of a carotenogenic chlorophyte from a coastal habitat with harsh environmental conditions (wide variations in solar irradiance, temperature, salinity and nutrient availability) identified as Haematococcus pluvialis Flotow. Increased (25‰) salinity exerted no adverse effect on the growth of the green BM1 cells. Under stressful conditions (high light, nitrogen and phosphorus deprivation), green vegetative cells of H. pluvialis BM1 grown in BG11 medium formed non-motile palmelloid cells and, eventually, hematocysts capable of a massive accumulation of the keto-carotenoid astaxanthin with a high nutraceutical and therapeutic potential. Routinely, astaxanthin was accumulated at the level of 4% of the cell dry weight (DW), reaching, under prolonged stress, 5.5% DW. Astaxanthin was predominantly accumulated in the form of mono- and diesters of fatty acids from C16 and C18 families. The palmelloids and hematocysts were characterized by the formation of red-colored cytoplasmic lipid droplets, increasingly large in size and number. The lipid droplets tended to merge and occupied almost the entire volume of the cell at the advanced stages of stress-induced carotenogenesis. The potential application of the new strain for the production of astaxanthin is discussed in comparison with the H. pluvialis strains currently employed in microalgal biotechnology.

  18. Production of astaxanthin from corn fiber as a value-added co-product of fuel ethanol fermentation

    Science.gov (United States)

    Five strains of the yeast Phaffia rhodozyma, NRRL Y-17268, NRRL Y-17270, ATCC 96594 (CBS 6938), ATCC 24202 (UCD 67-210), and ATCC 74219 (UBV-AX2) were tested for astaxanthin production using the major sugars derived from corn fiber, a byproduct from the wet milling of corn kernels that contains prim...

  19. Changes of Photosynthetic Behaviors and Photoprotection during Cell Transformation and Astaxanthin Accumulation in Haematococcus pluvialis Grown Outdoors in Tubular Photobioreactors

    Science.gov (United States)

    Zhang, Litao; Su, Fang; Zhang, Chunhui; Gong, Fengying; Liu, Jianguo

    2016-01-01

    The cell transformation from green motile cells to non-motile cells and astaxanthin accumulation can be induced in the green alga Haematococcus pluvialis cultured outdoors. In the initial 3 d of incubation (cell transformation phase), light absorption and photosynthetic electron transport became more efficient. After five days of incubation (astaxanthin accumulation phase), the light absorption per active reaction center (ABS/RC) increased, but the efficiency of electron transport (ψo) and the quantum yield of electron transport (φEo) decreased with increased time, indicating that the capacity of photosynthetic energy utilization decreased significantly during astaxanthin accumulation, leading to an imbalance between photosynthetic light absorption and energy utilization. It would inevitably aggravate photoinhibition under high light, e.g., at midday. However, the level of photoinhibition in H. pluvialis decreased as the incubation time increased, which is reflected by the fact that Fv/Fm determined at midday decreased significantly in the initial 3 d of incubation, but was affected very little after seven days of incubation, compared with that determined at predawn. This might be because the non-photochemical quenching, plastid terminal oxidase, photosystem I cyclic electron transport, defensive enzymes and the accumulated astaxanthin can protect cells against photoinhibition. PMID:28035956

  20. Analysis of Palmitoyl Apo-astaxanthinals, Apo-astaxanthinones, and their Epoxides by UHPLC-PDA-ESI-MS

    NARCIS (Netherlands)

    Weesepoel, Y.J.A.; Gruppen, H.; Bruijn, de W.J.C.; Vincken, J.P.

    2014-01-01

    Food products enriched with fatty acid-esterified xanthophylls may result in deviating dietary apo-carotenoids. Therefore, free astaxanthin and its mono- and dipalmitate esters were subjected to two degradation processes in a methanolic model system: light-accelerated autoxidation and hypochlorous a

  1. Nitrogen-depleted Chlorella zofingiensis produces astaxanthin, ketolutein and their fatty acid esters: a carotenoid metabolism study

    NARCIS (Netherlands)

    Mulders, K.J.M.; Weesepoel, Y.J.A.; Bodenes, C.; Lamers, P.P.; Vincken, J.P.; Martens, D.E.; Gruppen, H.; Wijffels, R.H.

    2015-01-01

    Natural carotenoids such as astaxanthin, ß,ß-carotene and lutein are pigments with a high market value. We studied the effects of nitrogen depletion on the carotenoid metabolism of Chlorella zofingiensis (Chlorophyta) and the subsequent treatment with diphenylamine (DPA), an inhibitor of the biosynt

  2. Study on the interaction of β-carotene and astaxanthin with trypsin and pepsin by spectroscopic techniques.

    Science.gov (United States)

    Li, Xiangrong; Li, Peihong

    2016-05-01

    β-Carotene and astaxanthin are two carotenoids with powerful antioxidant properties, but the binding mechanisms of β-carotene/astaxanthin to proteases remain unclear. In this study, the interaction of these two carotenoids with trypsin and pepsin was investigated using steady-state and time-resolved fluorescence measurements, synchronous fluorescence spectroscopy, UV-vis absorption spectroscopy and circular dichroism (CD) spectroscopy. The experimental results indicated that the quenching mechanisms of trypsin/pepsin by the two carotenoids are static processes. The binding constants of trypsin and pepsin with these two carotenoids are in the following order: astaxanthin-trypsin > astaxanthin-pepsin > β-carotene-trypsin > β-carotene-pepsin, respectively. Thermodynamic investigations revealed that the interaction between the two carotenoids and trypsin/pepsin is synergistically driven by enthalpy and entropy, and hydrophobic forces and electrostatic attraction have a significant role in the reactions. In addition, as shown by synchronous fluorescence spectroscopy, UV-vis absorption spectroscopy and CD, the two carotenoids may induce conformational and microenvironmental changes in trypsin/pepsin. The study provides an accurate and full basic data for clarifying the binding mechanisms of the two carotenoids with trypsin/pepsin and is helpful in understanding their effect on protein function and their biological activity in vivo.

  3. Changes of Photosynthetic Behaviors and Photoprotection during Cell Transformation and Astaxanthin Accumulation in Haematococcus pluvialis Grown Outdoors in Tubular Photobioreactors.

    Science.gov (United States)

    Zhang, Litao; Su, Fang; Zhang, Chunhui; Gong, Fengying; Liu, Jianguo

    2016-12-26

    The cell transformation from green motile cells to non-motile cells and astaxanthin accumulation can be induced in the green alga Haematococcus pluvialis cultured outdoors. In the initial 3 d of incubation (cell transformation phase), light absorption and photosynthetic electron transport became more efficient. After five days of incubation (astaxanthin accumulation phase), the light absorption per active reaction center (ABS/RC) increased, but the efficiency of electron transport (ψo) and the quantum yield of electron transport (φEo) decreased with increased time, indicating that the capacity of photosynthetic energy utilization decreased significantly during astaxanthin accumulation, leading to an imbalance between photosynthetic light absorption and energy utilization. It would inevitably aggravate photoinhibition under high light, e.g., at midday. However, the level of photoinhibition in H. pluvialis decreased as the incubation time increased, which is reflected by the fact that Fv/Fm determined at midday decreased significantly in the initial 3 d of incubation, but was affected very little after seven days of incubation, compared with that determined at predawn. This might be because the non-photochemical quenching, plastid terminal oxidase, photosystem I cyclic electron transport, defensive enzymes and the accumulated astaxanthin can protect cells against photoinhibition.

  4. Changes of Photosynthetic Behaviors and Photoprotection during Cell Transformation and Astaxanthin Accumulation in Haematococcus pluvialis Grown Outdoors in Tubular Photobioreactors

    Directory of Open Access Journals (Sweden)

    Litao Zhang

    2016-12-01

    Full Text Available The cell transformation from green motile cells to non-motile cells and astaxanthin accumulation can be induced in the green alga Haematococcus pluvialis cultured outdoors. In the initial 3 d of incubation (cell transformation phase, light absorption and photosynthetic electron transport became more efficient. After five days of incubation (astaxanthin accumulation phase, the light absorption per active reaction center (ABS/RC increased, but the efficiency of electron transport (ψo and the quantum yield of electron transport (φEo decreased with increased time, indicating that the capacity of photosynthetic energy utilization decreased significantly during astaxanthin accumulation, leading to an imbalance between photosynthetic light absorption and energy utilization. It would inevitably aggravate photoinhibition under high light, e.g., at midday. However, the level of photoinhibition in H. pluvialis decreased as the incubation time increased, which is reflected by the fact that Fv/Fm determined at midday decreased significantly in the initial 3 d of incubation, but was affected very little after seven days of incubation, compared with that determined at predawn. This might be because the non-photochemical quenching, plastid terminal oxidase, photosystem I cyclic electron transport, defensive enzymes and the accumulated astaxanthin can protect cells against photoinhibition.

  5. Self-assembly and energy transfer in artificial light-harvesting complexes of bacteriochlorophyll c with astaxanthin.

    Science.gov (United States)

    Alster, J; Polívka, T; Arellano, J B; Hříbek, P; Vácha, F; Hála, J; Pšenčík, J

    2012-03-01

    Chlorosomes, the light-harvesting antennae of green photosynthetic bacteria, are based on large aggregates of bacteriochlorophyll molecules. Aggregates with similar properties to those in chlorosomes can also be prepared in vitro. Several agents were shown to induce aggregation of bacteriochlorophyll c in aqueous environments, including certain lipids, carotenes, and quinones. A key distinguishing feature of bacteriochlorophyll c aggregates, both in vitro and in chlorosomes, is a large (>60 nm) red shift of their Q(y) absorption band compared with that of the monomers. In this study, we investigate the self-assembly of bacteriochlorophyll c with the xanthophyll astaxanthin, which leads to the formation of a new type of complexes. Our results indicate that, due to its specific structure, astaxanthin molecules competes with bacteriochlorophylls for the bonds involved in the aggregation, thus preventing the formation of any significant red shift compared with pure bacteriochlorophyll c in aqueous buffer. A strong interaction between both the types of pigments in the developed assemblies, is manifested by a rather efficient (~40%) excitation energy transfer from astaxanthin to bacteriochlorophyll c, as revealed by fluorescence excitation spectroscopy. Results of transient absorption spectroscopy show that the energy transfer is very fast (<500 fs) and proceeds through the S(2) state of astaxanthin.

  6. Favored isolation and rapid identification of the astaxanthin-producing yeast Xanthophyllomyces dendrorhous(Phaffia rhodozyma) from environmental samples.

    Science.gov (United States)

    Tognetti, Celia; Moliné, Martín; van Broock, María; Libkind, Diego

    2013-09-01

    Xanthophyllomyces dendrorhous (Phaffia rhodozyma) yeasts are biotechnologically exploited as a natural source of astaxanthin for aquaculture. Based on results of recent studies, it has become clear that this species possesses a greater genetic variability generating the necessity to uncover it and assess its potential for the astaxanthin industry. However, difficulties for the isolation of the X. dendrorhous hinder extensive environmental surveys which need to be carried out to better understand the habitat, distribution and genetic diversity of this species. We extensively searched for distinctive physiological traits of X. dendrorhours by testing phenotypic properties simultaneously with a panel of common sympatric fungi. As a result we obtained a new and innovative strategy for improving X. dendrorhous recovery rate and identification from environmental samples. This strategy involved the use of trehalose-based media, and a rapid X. dendrorhous identification method based on the simultaneous spectrophotometric detection of astaxanthin and UV-absorbing compounds (mycosporines). The proposed procedures proved effective in field trials conducted in natural environments of Patagonia (Argentina) and thus represent an important tool for the discovery of new astaxanthin-producing strains of X. dendrorhous useful for the aquaculture industry.

  7. Optimization of Ultrasound-assisted Extraction Procedure to Determine Astaxanthin in Xanthophyllomyces dendrorhous by Box-Behnken Designn

    Directory of Open Access Journals (Sweden)

    Wei Wu

    2013-11-01

    Full Text Available An ultrasonic-assisted extraction method has been developed for the effective extraction of astaxanthin from Xanthophyllomyces dendrorhous. Single-factor experiment design was employed to optimize the disruption temperature, disruption time, ethanol concentration, extraction time. The ethanol concentration was 60% ethanol in ethyl lactate and temperature for disrupting (40-60°C, time for disrupting extraction time (15-35 min, extraction time (20-40 min were used for further optimization of extraction conditions. The optimal conditions for the ultrasound-assisted extraction of astaxanthin were determined using Response Surface Methodology (RSM by Box-Behnken design. The optimal extraction conditions were that the yeast was disrupted at 49.08°C for 26.09 min under ultrasound irradiation of 200 W and then extracted for 32.43 min. Under optimal conditions, the astaxanthin content was 1472.85±43.64 &mug/g DW. This study introduces a simple, green and highly efficient method for extraction of astaxanthin fromX. dendrorhous

  8. Chiral quantum dot based materials

    Science.gov (United States)

    Govan, Joseph; Loudon, Alexander; Baranov, Alexander V.; Fedorov, Anatoly V.; Gun'ko, Yurii

    2014-05-01

    Recently, the use of stereospecific chiral stabilising molecules has also opened another avenue of interest in the area of quantum dot (QD) research. The main goal of our research is to develop new types of technologically important quantum dot materials containing chiral defects, study their properties and explore their applications. The utilisation of chiral penicillamine stabilisers allowed the preparation of new water soluble white emitting CdS quantum nanostructures which demonstrated circular dichroism in the band-edge region of the spectrum. It was also demonstrated that all three types of QDs (D-, L-, and Rac penicillamine stabilised) show very broad emission bands between 400 and 700 nm due to defects or trap states on the surfaces of the nanocrystals. In this work the chiral CdS based quantum nanostructures have also been doped by copper metal ions and new chiral penicilamine stabilized CuS nanoparticles have been prepared and investigated. It was found that copper doping had a strong effect at low levels in the synthesis of chiral CdS nanostructures. We expect that this research will open new horizons in the chemistry of chiral nanomaterials and their application in biotechnology, sensing and asymmetric synthesis.

  9. Effects of astaxanthin and emodin on the growth, stress resistance and disease resistance of yellow catfish (Pelteobagrus fulvidraco).

    Science.gov (United States)

    Liu, Fei; Shi, Hong-zhuan; Guo, Qiao-sheng; Yu, Ye-bing; Wang, Ai-ming; Lv, Fu; Shen, Wen-biao

    2016-04-01

    Yellow catfish (Pelteobagrus fulvidraco) has become a commercially important fish species in China and eastern Asia. High-density aquaculture has led to congestion and excessive stress and contributed to bacterial infection outbreaks that have caused high mortality. We investigated the effects of dietary supplementation with astaxanthin and emodin alone and in combination on the growth and stress resistance of yellow catfish. After 60 days of feeding, each group of fish (control, astaxanthin, emodin, and astaxanthin plus emodin (combination) groups) was exposed to acute crowding stress for 24 h, and a subsample of fish from the four groups was challenged with the bacterial septicemia pathogen Proteus mirabilis after the end of the crowding stress experiment. Compared with the control, the astaxanthin and emodin groups showed increases in serum total protein (TP), hepatic superoxide dismutase (SOD) activity and hepatic heat shock proteins 70 (HSP70) mRNA levels at 12 and 24 h after the initiation of crowding stress. The combination group exhibited increases in alanine aminotransferase (ALT) activity, aspartate aminotransferase (AST) activity, serum TP, hepatic SOD activity and hepatic HSP70 mRNA levels within 24 h after the initiation of crowding stress. However, decreases relative to the control were observed in the serum cortisol and glucose contents in the three treatment groups at 12 and 24 h after the initiation of crowding stress, in ALT and AST activity in the astaxanthin and emodin group at 24 h after the initiation of crowding stress, and in the serum lysozyme activity, serum alkaline phosphatase (ALP) activity, and hepatic catalase (CAT) and malondialdehyde (MDA) activity in the combination group at 24 h after the initiation of crowding stress. Additionally, the cumulative mortality after P. mirabilis infection was lower in all three treatment groups (57.00%-70.33%) than in the control (77.67%). Dietary supplementation with astaxanthin and emodin decreased

  10. The effect of astaxanthin on resistance of juvenile prawns Macrobrachium nipponense (Decapoda: Palaemonidae) to physical and chemical stress.

    Science.gov (United States)

    Tizkar, Babak; Seidavi, Alireza; Ponce-Palafox, Jesús Trinidad; Pourashoori, Parastoo

    2014-12-01

    In recent years, the use of new scientific techniques has effectively improved aquaculture production processes. Astaxanthin has various properties in aquaculture and its antioxidant benefits have been closely related to stress resistance; besides, it is an essential factor for growth in many crustaceans and fish. The objective of this study was to evaluate the resistance of prawn (Macrobrachium nipponense) fed diets containing different amounts of astaxanthin (AX) to the shock and stress of different physicochemical environments. A 70-day trial was conducted to evaluate the effect of supplementation of a source of astaxanthin (Carophyll Pink, 10% astaxanthin, w/w, Hoffman-La Roche, Switzerland) at various levels in the diet of M. nipponense juveniles. Four dry diets were prepared: AX0 without astaxanthin, AX50 with 50 mg/kg, AX100 with 100 mg/kg, and AX150 with 150 mg/kg astaxanthin. The feeding trial was conducted in a recirculation water system consisting of 12 fiberglass tanks (1000L) used for holding prawns. Three replicate aquaria were initially stocked with 36 org/m2 per tank. During the trial, prawns were maintained on a 12:12-h light:dark photoperiod with an ordinary incandescent lamp, and the water quality parameters were maintained as follows: water temperature, 25-26°C; salinity, 1 g/L; pH, 8.5-8.8; dissolved oxygen, 6.0-6.5 mg/L; and ammonia-nitrogen, 0.05 mg/L. Incorporation of AX, production output, and physiological condition were recorded after 10 weeks of feeding. At the end of the growing period, the prawns were exposed to thermal shock (0°C), ammonia (0.75 mg/L), and reduced oxygen (0.5 mg/L). The time to lethargy and the time to complete death of the prawns were recorded. The results showed that control prawns had the shortest time to lethargy and death compared with prawns subjected to the other treatments. The results of this study have shown that the amount of muscle tissue and gill carotenoids in prawn fed with an AX150 diet showed

  11. Preparation of new hybrid organic/inorganic polymeric chiral stationary phases for ligand-exchange chromatography

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Three new hybrid organic/inorganic polymeric ligand-exchange chiral stationary phases were developed by radical chain transfer reaction and surface grafting on silica gel, and successfully used for the enantioseparations of DL-amino acids and DL-hydroxyl acids. The resolutions were achieved by using water containing 2.0 × 10-4 mol/L of CuAc2 as a mobile phase, column temperature of 40 ℃, flow rate of 1.0 mL/min and detection at UV 254 mn. The elution order of D-isomer before L-isomer was observed for all DL-amino acids resolved except DL-Pro.

  12. Coupling chiral bosons to gravity

    CERN Document Server

    Braga, N R F; Braga, N R F; Wotzasek, C

    1995-01-01

    chiral boson actions of Floreanini and Jackiw (FJ), and of McClain,Wu and Yu (MWY) have been recently shown to be different representations of the same chiral boson theory. MWY displays manifest covariance and also a (gauge) symmetry that is hidden in the FJ side, which, on the other hand, displays the physical spectrum in a simple manner. We make use of the covariance of the MWY representation for the chiral boson to couple it to background gravity showing explicitly the equivalence with the previous results for the FJ representation

  13. Chiral gravity in higher dimensions

    CERN Document Server

    Ootsuka, T; Ura, K; Ootsuka, Takayoshi; Tanaka, Erico; Ura, Kousuke

    2003-01-01

    We construct a chiral theory of gravity in 7 and 8 dimensions, which are equivalent to Einstein-Cartan theory using less variables. In these dimensions, we can construct such higher dimensional chiral gravity because of the existence of gravitational instanton. The octonionic-valued variables in the theory represent the deviation from the gravitational instanton, and from their non-associativity, prevents the theory to be SO(n) gauge invariant. Still the chiral gravity holds G_2 (7-D), and Spin(7) (8-D) gauge symmetry.

  14. Chiral Fermions on the Lattice

    CERN Document Server

    Bietenholz, Wolfgang

    2010-01-01

    In the last century the non-perturbative regularization of chiral fermions was a long-standing problem. We review how this problem was finally overcome by the formulation of a modified but exact form of chiral symmetry on the lattice. This also provides a sound definition of the topological charge of lattice gauge configurations. We illustrate a variety of applications to QCD in the p-, the epsilon- and the delta-regime, where simulation results can now be related to Random Matrix Theory and Chiral Perturbation Theory. The latter contains Low Energy Constants as free parameters, and we comment on their evaluation from first principles of QCD.

  15. Field induced spin chirality and chirality switching in magnetic multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Tartakovskaya, Elena V., E-mail: elena_tartakovskaya@yahoo.com [Institute of Magnetism NAS of Ukraine, Vernadsky blvd 36b, 03142 Kiev (Ukraine); Institute of High Technologies, Taras Shevchenko National University of Kiev, 03022 Kiev (Ukraine)

    2015-05-01

    The physical origin of the field-induced spin chirality experimentally observed in rare earth multilayers is determined. It is shown that the effect is possible due to the interplay between solid-state exchange interactions (the Ruderman–Kittel–Kasuya–Yosida and the Dsyaloshinsky–Moriya interactions), the external magnetic field and a special confinement of magnetic constituents. The presented model describes a certain temperature dependence of the chirality factor in agreement with experimental data and opens a new way to design nanostructured objects with predicted handedness. - Highlights: • Field-induced spin chirality in magnetic multilayers is explained. • The roles of the RKKY, the DM and the Zeeman interactions are clarified. • Theoretical analysis of the chirality factor is in agreement with experimental data.

  16. Chiral Relaxation Time at the Chiral Crossover of Quantum Chromodynamics

    CERN Document Server

    Ruggieri, M; Chernodub, M

    2016-01-01

    We study microscopic processes responsible for chirality flips in the thermal bath of Quantum Chromodynamics at finite temperature and zero baryon chemical potential. We focus on the temperature range where the crossover from chirally broken phase to quark-gluon plasma takes place, namely $T \\simeq (150, 200)$ MeV. The processes we consider are quark-quark scatterings mediated by collective excitations with the quantum number of pions and $\\sigma$-meson, hence we refer to these processes simply as \\sugg{to} one-pion (one-$\\sigma$) exchange\\sugg{s}. We use a Nambu-Jona-Lasinio model to compute equilibrium properties of the thermal bath, as well as the relevant scattering kernel to be used in the collision integral to estimate the chiral relaxation time $\\tau$. We find $\\tau\\simeq 0.1 \\div 1$ fm/c around the chiral crossover.

  17. Consistent chiral kinetic theory in Weyl materials: chiral magnetic plasmons

    CERN Document Server

    Gorbar, E V; Shovkovy, I A; Sukhachov, P O

    2016-01-01

    We argue that the correct definition of the electric current in the chiral kinetic theory for Weyl materials should include the Chern--Simons contribution that makes the theory consistent with the local conservation of the electric charge in electromagnetic and strain-induced pseudoelectromagnetic fields. By making use of such a kinetic theory, we study the plasma frequencies of collective modes in Weyl materials in constant magnetic and pseudomagnetic fields taking into account the effects of dynamical electromagnetism. We show that the collective modes are chiral plasmons. While the plasma frequency of the longitudinal collective mode coincides with the Langmuir one, this mode is unusual because it is characterized not only by oscillations of the electric current density, but also oscillations of the chiral current density. The latter are triggered by a dynamical version of the chiral electric separation effect. We also find that the plasma frequencies of the transverse modes split up in a magnetic field. T...

  18. Application of derivative ratio spectrophotometry for determination of β-carotene and astaxanthin from Phaffia rhodozyma extract

    Institute of Scientific and Technical Information of China (English)

    NI Hui; HE Guo-qing; RUAN Hui; CHEN Qi-he; CHEN Feng

    2005-01-01

    A derivative ratio spectrophotometric method was used for the simultaneous determination of β-carotene and astaxanthin produced from Phaffia rhodozyma. Absorbencies of a series of the standard carotenoids in the range of 441 nm to 490nm demonstrated that their absorptive spectra accorded with Beer's law and that the additivity when the concentrations of β-carotene and astaxanthin and their mixture were within the range of 0 to 5 μg/ml, 0 to 6 μg/ml, and 0 to 6 μg/ml, respectively.When the wavelength interval (△λ) at 2 nm was selected to calculate the first derivative ratio spectra values, the first derivative amplitudes at 461 nm and 466 nm were suitable for quantitatively determining β-carotene and astaxanthin, respectively. Effect of divisor on derivative ratio spectra could be neglected; any concentration used as divisor in range of 1.0 to 4.0 μg/ml is ideal for calculating the derivative ratio spectra values of the two carotenoids. Calibration graphs were established for β-carotene within 0-6.0 μg/ml and for astaxanthin within 0-5.0 μg/ml with their corresponding regressive equations in: y=-0.0082x-0.0002 and y=0.0146x-0.0006, respectively. R-square values in excess of 0.999 indicated the good linearity of the calibration graphs. Sample recovery rates were found satisfactory (>99%) with relative standard deviations (RSD) of less than 5%. This method was successfully applied to simultaneous determination of β-carotene and astaxanthin in the laboratory-prepared mixtures and the extract from the Phaffia rhodozyma culture.

  19. Studies of high-K isomers at TRIUMF-ISAC

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.B. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); Walker, P.M. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); Department of Physics, University of Surrey, Guildford, Surrey (United Kingdom); Chakrawarthy, R.S. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); Austin, R.A.E. [Department of Physics and Astronomy, McMaster University, Hamilton, ON (Canada); Ball, G.C. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); Carroll, J.J. [Department of Physics and Astronomy, Youngstown State University, Ohio (United States); Cunningham, E. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); Finlay, P. [Department of Physics, University of Guelph, Guelph, ON (Canada); Garrett, P.E. [Lawrence Livermore National Laboratory, Livermore, California (United States); Grinyer, G.F. [Department of Physics, University of Guelph, Guelph, ON (Canada); Hackman, G. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); Hyland, B. [Department of Physics, University of Guelph, Guelph, ON (Canada); Koopmans, K. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); Department of Physics and Astronomy, McMaster University, Hamilton, ON (Canada); Kulp, W.D. [School of Physics, Georgia Institute of Technology, Atlanta, Georgia (United States); Leslie, J.R. [Physics Department, Queen' s University, Kingston, ON (Canada); Phillips, A.A. [Department of Physics, University of Guelph, Guelph, ON (Canada); Propri, R. [Department of Physics and Astronomy, Youngstown State University, Ohio (United States); Regan, P.H. [Department of Physics, University of Surrey, Guildford, Surrey (United Kingdom); Sarazin, F. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); Schumaker, M.A. [Department of Physics, University of Guelph, Guelph, ON (Canada); Scraggs, H.C. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada)] [and others

    2004-12-27

    The properties of high-K isomers have been investigated by measuring {gamma} rays from a source of the 31-year {sup 178}Hf{sup m2} isomer and from the decay of implanted {sup 178,179}Lu beams. Low-intensity transitions have been identified in the decay of {sup 178}Hf{sup m2}, demonstrating a consistent extension of K-hindrance systematics to higher multipolarities, and elucidating the spin-dependence of the mixing between the two K{sup {pi}} = 8{sup -} bands. A search is underway for new isomers in {sup 178,179}Lu and the preliminary results of the analysis are reported.

  20. Detection of Actinides via Nuclear Isomer De-Excitation

    Energy Technology Data Exchange (ETDEWEB)

    Francy, Christopher J. [Oregon State Univ., Corvallis, OR (United States)

    2009-07-01

    This dissertation discusses a data collection experiment within the Actinide Isomer Identification project (AID). The AID project is the investigation of an active interrogation technique that utilizes nuclear isomer production, with the goal of assisting in the interdiction of illicit nuclear materials. In an attempt to find and characterize isomers belonging to 235U and its fission fragments, a 232Th target was bombarded with a monoenergetic 6Li ion beam, operating at 45 MeV.

  1. Properties of neutron-rich hafnium high-spin isomers

    CERN Multimedia

    Tungate, G; Walker, P M; Neyens, G; Billowes, J; Flanagan, K; Koester, U H; Litvinov, Y

    It is proposed to study highly-excited multi-quasiparticle isomers in neutron-rich hafnium (Z=72) isotopes. Long half-lives have already been measured for such isomers in the storage ring at GSI, ensuring their accessibility with ISOL production. The present proposal focuses on:\\\\ (i) an on-line experiment to measure isomer properties in $^{183}$Hf and $^{184}$Hf, and\\\\ (ii) an off-line molecular breakup test using REXTRAP, to provide Hf$^{+}$ beams for future laser spectroscopy and greater sensitivity for the future study of more neutron-rich isotopes.

  2. Separation and identification of indene–C70 bisadduct isomers

    Science.gov (United States)

    Zhang, Bolong; Subbiah, Jegadesan; Jones, David J

    2016-01-01

    Summary Following an initial work on the isolation of a single geometric isomer from an indene–C70 bisadduct (IC70BA) mixture, we report the full fractionation and identification of the bisadduct species in the material. Eleven fractions of IC70BA isomers were separated by high-performance liquid chromatography. A number of fractions contained relatively pure isomer species and their configuration were deduced using a variety of analytical techniques including 1H and 13C NMR and UV–vis spectroscopy. The electrochemical properties and the organic solar cell device performance were investigated for fractions where a reasonable quantity of sample could be isolated. PMID:27340480

  3. Astaxanthin Inhibits Acetaldehyde-Induced Cytotoxicity in SH-SY5Y Cells by Modulating Akt/CREB and p38MAPK/ERK Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Tingting Yan

    2016-03-01

    Full Text Available Excessive alcohol consumption can lead to brain tissue damage and cognitive dysfunction. Acetaldehyde, the most toxic metabolite of ethanol, mediates the brain tissue damage and cognitive dysfunction induced by chronic excessive alcohol consumption. In this study, the effect of astaxanthin, a marine bioactive compound, on acetaldehyde-induced cytotoxicity was investigated in SH-SY5Y cells. It was found that astaxanthin protected cells from apoptosis by ameliorating the effect of acetaldehyde on the expression of Bcl-2 family proteins, preventing the reduction of anti-apoptotic protein Bcl-2 and the increase of pro-apoptotic protein Bak induced by acetaldehyde. Further analyses showed that astaxanthin treatment inhibited acetaldehyde-induced reduction of the levels of activated Akt and cyclic AMP-responsive element binding protein (CREB. Astaxanthin treatment also prevented acetaldehyde-induced increase of the level of activated p38 mitogen-activated protein kinase (MAPK and decrease of the level of activated extracellular signal-regulated kinases (ERKs. Activation of Akt/CREB pathway promotes cell survival and is involved in the upregulation of Bcl-2 gene. P38MAPK plays a critical role in apoptotic events while ERKs mediates the inhibition of apoptosis. Thus, astaxanthin may inhibit acetaldehyde-induced apoptosis through promoting the activation of Akt/CREB and ERKs and blocking the activation of p38MAPK. In addition, astaxanthin treatment suppressed the oxidative stress induced by acetaldehyde and restored the antioxidative capacity of SH-SY5Y cells. Therefore, astaxanthin may protect cells against acetaldehyde-induced cytotoxicity through maintaining redox balance and modulating apoptotic and survival signals. The results suggest that astaxanthin treatment may be beneficial for preventing neurotoxicity associated with acetaldehyde and excessive alcohol consumption.

  4. Astaxanthin Inhibits Acetaldehyde-Induced Cytotoxicity in SH-SY5Y Cells by Modulating Akt/CREB and p38MAPK/ERK Signaling Pathways.

    Science.gov (United States)

    Yan, Tingting; Zhao, Yan; Zhang, Xia; Lin, Xiaotong

    2016-03-10

    Excessive alcohol consumption can lead to brain tissue damage and cognitive dysfunction. Acetaldehyde, the most toxic metabolite of ethanol, mediates the brain tissue damage and cognitive dysfunction induced by chronic excessive alcohol consumption. In this study, the effect of astaxanthin, a marine bioactive compound, on acetaldehyde-induced cytotoxicity was investigated in SH-SY5Y cells. It was found that astaxanthin protected cells from apoptosis by ameliorating the effect of acetaldehyde on the expression of Bcl-2 family proteins, preventing the reduction of anti-apoptotic protein Bcl-2 and the increase of pro-apoptotic protein Bak induced by acetaldehyde. Further analyses showed that astaxanthin treatment inhibited acetaldehyde-induced reduction of the levels of activated Akt and cyclic AMP-responsive element binding protein (CREB). Astaxanthin treatment also prevented acetaldehyde-induced increase of the level of activated p38 mitogen-activated protein kinase (MAPK) and decrease of the level of activated extracellular signal-regulated kinases (ERKs). Activation of Akt/CREB pathway promotes cell survival and is involved in the upregulation of Bcl-2 gene. P38MAPK plays a critical role in apoptotic events while ERKs mediates the inhibition of apoptosis. Thus, astaxanthin may inhibit acetaldehyde-induced apoptosis through promoting the activation of Akt/CREB and ERKs and blocking the activation of p38MAPK. In addition, astaxanthin treatment suppressed the oxidative stress induced by acetaldehyde and restored the antioxidative capacity of SH-SY5Y cells. Therefore, astaxanthin may protect cells against acetaldehyde-induced cytotoxicity through maintaining redox balance and modulating apoptotic and survival signals. The results suggest that astaxanthin treatment may be beneficial for preventing neurotoxicity associated with acetaldehyde and excessive alcohol consumption.

  5. Improvement of ISOM by using filter

    Directory of Open Access Journals (Sweden)

    Imen Chaabouni

    2012-05-01

    Full Text Available Image compression helps in storing the transmitted data in proficient way by decreasing its redundancy. This technique helps in transferring more digital or multimedia data over internet as it increases the storage space. It is important to maintain the image quality even if it is compressed to certain extent. Depend upon this the image compression is classified into two categories : lossy and lossless image compression. There are many lossy digital image compression techniques exists. Among this Incremental Self Organizing Map is a familiar one. The good pictures quality can be retrieved if image denoising technique is used for compression and also provides better compression ratio. Image denoising is an important pre-processing step for many image analysis and computer vision system. It refers to the task of recovering a good estimate of the true image from a degraded observation without altering and changing useful structure in the image such as discontinuities and edges. Many approaches have been proposed to remove the noise effectively while preserving the original image details and features as much as possible. This paper proposes a technique for image compression using Incremental Self Organizing Map (ISOM with Discret Wavelet Transform (DWT by applying filtering techniques which play a crucial role in enhancing the quality of a reconstructed image. The experimental result shows that the proposed technique obtained better compression ratio value.

  6. Chirality in photonic systems

    Science.gov (United States)

    Solnyshkov, Dmitry; Malpuech, Guillaume

    2016-10-01

    The optical modes of photonic structures are the so-called TE and TM modes that bring intrinsic spin-orbit coupling and chirality to these systems. This, combined with the unique flexibility of design of the photonic potential, and the possibility to mix photon states with excitonic resonances, sensitive to magnetic field and interactions, allows us to achieve many phenomena, often analogous to other solid-state systems. In this contribution, we review in a qualitative and comprehensive way several of these realizations, namely the optical spin Hall effect, the creation of spin currents protected by a non-trivial geometry, the Berry curvature for photons, and the photonic/polaritonic topological insulator.

  7. Reducible chiral metamaterials

    CERN Document Server

    Ciattoni, Alessandro; Rizza, Carlo

    2016-01-01

    We introduce the concept of 3D reducible metamaterials whose constituent permittivity can be modelled by a factorized profile. The separated cartesian coordinates dependence, easily achieved in all-optical reconfigurable materials, allows to physically regard a reducible metamaterial as a superposition of three fictitious 1D generating media. We prove that, in the long-wavelength limit, the electromagnetic response of reducible metamaterials can be reconstructed from the properties of the 1D generating media whose interplay provides large freedom to control the electromagnetic chirality. Our approach introduces an unprecedented decomposition strategy in metamaterial science which allows the full ab-initio and flexible design of a complex 3D bianisotropic response by using 1D metamaterials as basic building blocks.

  8. Amino Acids and Chirality

    Science.gov (United States)

    Cook, Jamie E.

    2012-01-01

    Amino acids are among the most heavily studied organic compound class in carbonaceous chondrites. The abundance, distributions, enantiomeric compositions, and stable isotopic ratios of amino acids have been determined in carbonaceous chondrites fi'om a range of classes and petrographic types, with interesting correlations observed between these properties and the class and typc of the chondritcs. In particular, isomeric distributions appear to correlate with parent bodies (chondrite class). In addition, certain chiral amino acids are found in enantiomeric excess in some chondrites. The delivery of these enantiomeric excesses to the early Earth may have contributed to the origin of the homochirality that is central to life on Earth today. This talk will explore the amino acids in carbonaceous chondritcs and their relevance to the origin of life.

  9. Chiral Phosphinate Degradation by the Fusarium Species: Scope and Limitation of the Process

    Science.gov (United States)

    Brzezińska-Rodak, Małgorzata

    2013-01-01

    Biodegradable capacities of fungal strains of Fusarium oxysporum (DSMZ 2018) and Fusarium culmorum (DSMZ 1094) were tested towards racemic mixture of chiral 2-hydroxy-2-(ethoxyphenylphosphinyl) acetic acid—a compound with two stereogenic centres. The effectiveness of decomposition was dependent on external factors such as temperature and time of the process. Optimal conditions of complete mineralization were established. Both Fusarium species were able to biodegrade every isomer of tested compound at 30°C, but F. culmorum required 10 days and F. oxysporum 11 days to accomplish the process, which was continuously monitored using the 31P NMR technique. PMID:24324893

  10. Chiral Phosphinate Degradation by the Fusarium Species: Scope and Limitation of the Process

    Directory of Open Access Journals (Sweden)

    Natalia Kmiecik

    2013-01-01

    Full Text Available Biodegradable capacities of fungal strains of Fusarium oxysporum (DSMZ 2018 and Fusarium culmorum (DSMZ 1094 were tested towards racemic mixture of chiral 2-hydroxy-2-(ethoxyphenylphosphinyl acetic acid—a compound with two stereogenic centres. The effectiveness of decomposition was dependent on external factors such as temperature and time of the process. Optimal conditions of complete mineralization were established. Both Fusarium species were able to biodegrade every isomer of tested compound at 30°C, but F. culmorum required 10 days and F. oxysporum 11 days to accomplish the process, which was continuously monitored using the 31P NMR technique.

  11. Domains of Disoriented Chiral Condensate

    CERN Document Server

    Amado, R D; Lu, Yang

    1996-01-01

    The probability distribution of neutral pion fraction from independent domains of disoriented chiral condensate is characterized. The signal for the condensate is clear for a small number of domains but is greatly reduced for more than three.

  12. Review of chiral perturbation theory

    Indian Academy of Sciences (India)

    B Ananthanarayan

    2003-11-01

    A review of chiral perturbation theory and recent developments on the comparison of its predictions with experiment is presented. Some interesting topics with scope for further elaboration are touched upon.

  13. Chiral Dynamics With Wilson Fermions

    CERN Document Server

    Splittorff, K

    2012-01-01

    Close to the continuum the lattice spacing affects the smallest eigenvalues of the Wilson Dirac operator in a very specific manner determined by the way in which the discretization breaks chiral symmetry. These effects can be computed analytically by means of Wilson chiral perturbation theory and Wilson random matrix theory. A number of insights on chiral Dynamics with Wilson fermions can be obtained from the computation of the microscopic spectrum of the Wilson Dirac operator. For example, the unusual volume scaling of the smallest eigenvalues observed in lattice simulations has a natural explanation. The dynamics of the eigenvalues of the Wilson Dirac operator also allow us to determine the additional low energy constants of Wilson chiral perturbation theory and to understand why the Sharpe-Singleton scenario is only realized in unquenched simulations.

  14. Chirally motivated K - nuclear potentials

    Science.gov (United States)

    Cieplý, A.; Friedman, E.; Gal, A.; Gazda, D.; Mareš, J.

    2011-08-01

    In-medium subthreshold Kbar N scattering amplitudes calculated within a chirally motivated meson-baryon coupled-channel model are used self consistently to confront K- atom data across the periodic table. Substantially deeper K- nuclear potentials are obtained compared to the shallow potentials derived in some approaches from threshold Kbar N amplitudes, with Re VK-chiral = - (85 ± 5) MeV at nuclear matter density. When Kbar NN contributions are incorporated phenomenologically, a very deep K- nuclear potential results, Re VK-chiral + phen . = - (180 ± 5) MeV, in agreement with density dependent potentials obtained in purely phenomenological fits to the data. Self consistent dynamical calculations of K--nuclear quasibound states generated by VK-chiral are reported and discussed.

  15. Chiral Quark Model of Mesons

    CERN Document Server

    Wang, X J; Wang, Xiao-Jun; Yan, Mu-Lin

    1999-01-01

    We study SU(3)$_L\\timesSU(3)_R$ chiral quark model of mesons up to next leading order of $1/N_c$ expansion. Composite vector and axial-vector mesons resonances are introduced via non-linear realization of chiral SU(3) and vector meson dominant. Effects of one-loop graphs of pseudoscalar, vector and axial-vector mesons is calculated systematically and the significant results are obtained. Correction of effective gluon interaction is studied too. The light quark masses are introduced via new mechanism which agree with phenomenology and the requirement of chiral symmetry. Up to powers four of derivatives, chiral effective lagrangian of mesons is derived and evaluated to next leading order of $1/N_c$. Low energy limit of the model is examined. Ten low energy coupling constants $L_i(i=1,2,...,10)$ in ChPT are obtained and agree with ChPT well.

  16. Antibacterial adhesion of borneol-based polymer via surface chiral stereochemistry.

    Science.gov (United States)

    Luo, Lingqiong; Li, Guofeng; Luan, Di; Yuan, Qipeng; Wei, Yen; Wang, Xing

    2014-01-01

    During its adhesion on external surfaces, a cell exhibits obvious inclination to different molecular chirality, which encourages us to develop a new type of antibacterial material catering to the "chiral taste" of bacteria. On the basis of the natural product borneol (a camphane-type bicyclic monoterpene), a series of borneol-based polymer, polyborneolacrylate (PBA), was successfully prepared and showed superior antibacterial adhesion properties resulting from the borneol isomers on material surface. The results of this study reveal that bacteria simply dislike this type of stubborn surface of PBA, and the PBA surface stereochemistry contributes to the interfacial antibacterial activities. The PBA polymers were evaluated as noncytotoxic and can be simply synthesized, demonstrating their great potential for biomedical applications.

  17. The determination of botanical origin of honeys based on enantiomer distribution of chiral volatile organic compounds.

    Science.gov (United States)

    Špánik, Ivan; Pažitná, Alexandra; Šiška, Peter; Szolcsányi, Peter

    2014-09-01

    The enantiomer ratios of chiral volatile organic compounds in rapeseed, chestnut, orange, acacia, sunflower and linden honeys were determined by multi-dimensional gas chromatography using solid phase microextraction (SPME) as a sample pre-treatment procedure. Linalool oxides, linalool and hotrienol were present at the highest concentration levels, while significantly lower amounts of α-terpineol, 4-terpineol and all isomers of lilac aldehydes were found in all studied samples. On the other hand, enantiomer distribution of some chiral organic compounds in honey depends on their botanical origin. The significant differences in enantiomer ratio of linalool were observed for rapeseed honey that allows us to distinguish this type of honey from the other ones. The enantiomer ratios of lilac aldehydes were useful for distinguishing of orange and acacia honey from other studied monofloral honeys. Similarly, different enantiomer ratio of 4-terpineol was found for sunflower honeys.

  18. Homogenization of resonant chiral metamaterials

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Menzel, C.; Rockstuhl, Carsten

    2010-01-01

    Homogenization of metamaterials is a crucial issue as it allows to describe their optical response in terms of effective wave parameters as, e.g., propagation constants. In this paper we consider the possible homogenization of chiral metamaterials. We show that for meta-atoms of a certain size...... an analytical criterion for performing the homogenization and a tool to predict the homogenization limit. We show that strong coupling between meta-atoms of chiral metamaterials may prevent their homogenization at all....

  19. Chiral thermodynamics of nuclear matter

    Energy Technology Data Exchange (ETDEWEB)

    Fiorilla, Salvatore

    2012-10-23

    The equation of state of nuclear matter is calculated at finite temperature in the framework of in-medium chiral perturbation theory up to three-loop order. The dependence of its thermodynamic properties on the isospin-asymmetry is investigated. The chiral quark condensate is evaluated for symmetric nuclear matter. Its behaviour as a function of density and temperature sets important nuclear physics constraints for the QCD phase diagram.

  20. Baryon spectrum and chiral dynamics

    CERN Document Server

    Glozman, L Ya

    1995-01-01

    New results on baryon structure and spectrum developed in collaboration with Dan Riska [1-4] are reported. The main idea is that beyond the chiral symmetry spontaneous breaking scale light and strange baryons should be considered as systems of three constituent quarks with an effective confining interaction and a chiral interaction that is mediated by the octet of Goldstone bosons (pseudoscalar mesons) between the constituent quarks.

  1. Protective effects of astaxanthin on ConA-induced autoimmune hepatitis by the JNK/p-JNK pathway-mediated inhibition of autophagy and apoptosis.

    Directory of Open Access Journals (Sweden)

    Jingjing Li

    Full Text Available Astaxanthin, a potent antioxidant, exhibits a wide range of biological activities, including antioxidant, atherosclerosis and antitumor activities. However, its effect on concanavalin A (ConA-induced autoimmune hepatitis remains unclear. The aim of this study was to investigate the protective effects of astaxanthin on ConA-induced hepatitis in mice, and to elucidate the mechanisms of regulation.Autoimmune hepatitis was induced in in Balb/C mice using ConA (25 mg/kg, and astaxanthin was orally administered daily at two doses (20 mg/kg and 40 mg/kg for 14 days before ConA injection. Levels of serum liver enzymes and the histopathology of inflammatory cytokines and other maker proteins were determined at three time points (2, 8 and 24 h. Primary hepatocytes were pretreated with astaxanthin (80 μM in vitro 24 h before stimulation with TNF-α (10 ng/ml. The apoptosis rate and related protein expression were determined 24 h after the administration of TNF-α.Astaxanthin attenuated serum liver enzymes and pathological damage by reducing the release of inflammatory factors. It performed anti-apoptotic effects via the descending phosphorylation of Bcl-2 through the down-regulation of the JNK/p-JNK pathway.This research firstly expounded that astaxanthin reduced immune liver injury in ConA-induced autoimmune hepatitis. The mode of action appears to be downregulation of JNK/p-JNK-mediated apoptosis and autophagy.

  2. Amelioration of capillary regression and atrophy of the soleus muscle in hindlimb-unloaded rats by astaxanthin supplementation and intermittent loading.

    Science.gov (United States)

    Kanazashi, Miho; Tanaka, Masayuki; Murakami, Shinichiro; Kondo, Hiroyo; Nagatomo, Fumiko; Ishihara, Akihiko; Roy, Roland R; Fujino, Hidemi

    2014-08-01

    A chronic decrease in neuromuscular activity (activation and/or loading) results in muscle atrophy and capillary regression that are due, in part, to the overproduction of reactive oxygen species. We have reported that antioxidant treatment with astaxanthin attenuates the overexpression of reactive oxygen species in atrophied muscles that, in turn, ameliorates capillary regression in hindlimb-unloaded rats. Astaxanthin supplementation, however, had little effect on muscle mass and fibre cross-sectional area. In contrast, intermittent loading of the hindlimbs of hindlimb-unloaded rats ameliorates muscle atrophy. Therefore, we hypothesized that the combination of astaxanthin supplementation and intermittent loading would attenuate both muscle atrophy and capillary regression during hindlimb unloading. As expected, 2 weeks of hindlimb unloading resulted in atrophy, a decrease in capillary volume and a shift towards smaller-diameter capillaries in the soleus muscle. Intermittent loading alone (1 h of cage ambulation per day) attenuated atrophy of the soleus, while astaxanthin treatment alone maintained the capillary network to near control levels. The combination of intermittent loading and astaxanthin treatment, however, ameliorated atrophy of the soleus and maintained the capillary volume and luminal diameters and the superoxide dismutase-1 protein levels near control values. These results indicate that intermittent loading combined with astaxanthin supplementation could be an effective therapy for both the muscle atrophy and the capillary regression associated with a chronic decrease in neuromuscular activity.

  3. Carotenoids and Their Isomers: Color Pigments in Fruits and Vegetables

    Directory of Open Access Journals (Sweden)

    Yueming Jiang

    2011-02-01

    Full Text Available Fruits and vegetables are colorful pigment-containing food sources. Owing to their nutritional benefits and phytochemicals, they are considered as ‘functional food ingredients’. Carotenoids are some of the most vital colored phytochemicals, occurring as all-trans and cis-isomers, and accounting for the brilliant colors of a variety of fruits and vegetables. Carotenoids extensively studied in this regard include β-carotene, lycopene, lutein and zeaxanthin. Coloration of fruits and vegetables depends on their growth maturity, concentration of carotenoid isomers, and food processing methods. This article focuses more on several carotenoids and their isomers present in different fruits and vegetables along with their concentrations. Carotenoids and their geometric isomers also play an important role in protecting cells from oxidation and cellular damages.

  4. Reelfoot and Lake Isom National Wildlife Refuges : Wildlife Inventory Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This wildlife inventory plan for Reelfoot and Lake Isom National Wildlife Refuges includes survey procedure forms that represent cost effective inventory of the...

  5. Carotenoids and their isomers: color pigments in fruits and vegetables.

    Science.gov (United States)

    Khoo, Hock-Eng; Prasad, K Nagendra; Kong, Kin-Weng; Jiang, Yueming; Ismail, Amin

    2011-02-18

    Fruits and vegetables are colorful pigment-containing food sources. Owing to their nutritional benefits and phytochemicals, they are considered as 'functional food ingredients'. Carotenoids are some of the most vital colored phytochemicals, occurring as all-trans and cis-isomers, and accounting for the brilliant colors of a variety of fruits and vegetables. Carotenoids extensively studied in this regard include β-carotene, lycopene, lutein and zeaxanthin. Coloration of fruits and vegetables depends on their growth maturity, concentration of carotenoid isomers, and food processing methods. This article focuses more on several carotenoids and their isomers present in different fruits and vegetables along with their concentrations. Carotenoids and their geometric isomers also play an important role in protecting cells from oxidation and cellular damages.

  6. Aromaticity of All Possible C26N2 Isomers

    Institute of Scientific and Technical Information of China (English)

    TANG,Ming-Hui; ABLIKIM,Kerim

    2008-01-01

    The aromaticity of all possible heterofullerenes C26N2 and C28 based on Td symmetry has been studied by means of the topological resonance energy and percentage topological resonance energy methods. The relationship between the aromaticity of the C26N2 isomers and the sites where nitrogen atoms dope at the C28 cage has been discussed. The calculation results show that the most stable isomer of C26N2 derivatives is formed by nitrogen atoms doping at the two tetrahedral vertices. C26N2 isomers are more stable than C28, but the C26N2-2 isomers are less stable than C4-28. The effect of nitrogen substitution on C28 stability was investigated by the topological charge stabilization rule.

  7. Reelfoot/Lake Isom National Wildlife Refuge: Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Reelfoot and Lake Isom NWRs for the next 15 years. This plan outlines the refuges'...

  8. Bottom-up synthesis of chiral covalent organic frameworks and their bound capillaries for chiral separation.

    Science.gov (United States)

    Qian, Hai-Long; Yang, Cheng-Xiong; Yan, Xiu-Ping

    2016-07-12

    Covalent organic frameworks (COFs) are a novel class of porous materials, and offer great potential for various applications. However, the applications of COFs in chiral separation and chiral catalysis are largely underexplored due to the very limited chiral COFs available and their challenging synthesis. Here we show a bottom-up strategy to construct chiral COFs and an in situ growth approach to fabricate chiral COF-bound capillary columns for chiral gas chromatography. We incorporate the chiral centres into one of the organic ligands for the synthesis of the chiral COFs. We subsequently in situ prepare the COF-bound capillary columns. The prepared chiral COFs and their bound capillary columns give high resolution for the separation of enantiomers with excellent repeatability and reproducibility. The proposed strategy provides a promising platform for the synthesis of chiral COFs and their chiral separation application.

  9. Bottom-up synthesis of chiral covalent organic frameworks and their bound capillaries for chiral separation

    Science.gov (United States)

    Qian, Hai-Long; Yang, Cheng-Xiong; Yan, Xiu-Ping

    2016-07-01

    Covalent organic frameworks (COFs) are a novel class of porous materials, and offer great potential for various applications. However, the applications of COFs in chiral separation and chiral catalysis are largely underexplored due to the very limited chiral COFs available and their challenging synthesis. Here we show a bottom-up strategy to construct chiral COFs and an in situ growth approach to fabricate chiral COF-bound capillary columns for chiral gas chromatography. We incorporate the chiral centres into one of the organic ligands for the synthesis of the chiral COFs. We subsequently in situ prepare the COF-bound capillary columns. The prepared chiral COFs and their bound capillary columns give high resolution for the separation of enantiomers with excellent repeatability and reproducibility. The proposed strategy provides a promising platform for the synthesis of chiral COFs and their chiral separation application.

  10. Direct Measurement of the Thermodynamics of Chiral Recognition in Bile Salt Micelles.

    Science.gov (United States)

    Anderson, Shauna L; Rovnyak, David; Strein, Timothy G

    2016-04-01

    Isothermal titration calorimetry (ITC) is shown to be a sensitive reporter of bile salt micellization and chiral recognition. Detailed ITC characterization of bile micelle formation as well as the chiral recognition capabilities of sodium cholate (NaC), deoxycholate (NaDC), and taurodeoxycholate (NaTDC) micelle systems are reported. The ΔH(demic) of these bile salt micelle systems is directly observable and is strongly temperature-dependent, allowing also for the determination of ΔCp(demic). Using the pseudo-phase separation model, ΔG(demic) and TΔS(demic) were also calculated. Chirally selective guest-host binding of model racemic compounds 1,1'-bi-2-napthol (BN) and 1,1'-binaphthyl-2,2'-diylhydrogenphosphate (BNDHP) to bile salt micelles was then investigated. The S-isomer was shown to bind more tightly to the bile salt micelles in all cases. A model was developed that allows for the quantitative determination of the enthalpic difference in binding affinity that corresponds to chiral selectivity, which is on the order of 1 kJ mol(-1).

  11. Using the Chiral Organophosphorus Derivatizing Agents for Determination of the Enantiomeric Composition of Chiral Carboxylic Acids by 31PNMR Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    Chao CHE; Zhong Ning ZHANG; Gui Lan HUANG; Xin Xing WANG; Zhao Hai QIN

    2004-01-01

    The use of chiral organophosphorus derivatizing agents prepared in situ from chiral tartrate or chiral diamine for the 31PNMR determination of the enantiomeric composition of chiral carboxylic acids is described. The method is accurate, reliable and convenient.

  12. Comparative study on pharmacological effects of DM-phencynonate hydrochloride and its optical isomers

    Institute of Scientific and Technical Information of China (English)

    Li-yun WANG; Jian-quan ZHENG; Yun WANG; Bo-hua ZHONG; Jin-xiu RUAN; Ke-liang LIU

    2005-01-01

    Aim: The 3 -azabicyclo(3,3, 1)nonanyl-9-α-yl-α-cyclopentyl-α-phenyl-α-glycolate (DM-phencynonate hydrochloride, DMCPG) is a demethylated metabolite of 3-methyl-3-azabicyclo(3,3,1)nonanyl-9-α-yl-α-cyclopentyl-α-phenyl-α-glycolate (phencynonate hydrochloride, CPG). (±)DMCPG had one chiral center and two enantiomers [R(-) and S(+)DMCPG]. Here we carried out a comparative study of the pharmacological profiles of these optical isomers. Methods: Affinity and relative efficacy were tested using a radioligand-binding assay with muscarinic acetylcholine receptors from the rat cerebral cortex. Pharmacological activity was assessed in three individual experiments: (1) potentiating the effect of a subthreshold hypnotic dose of sodium pentobarbital; (2) inhibiting oxotremorineinduced salivation; and (3) inhibiting the contractile response to carbachol.Results: In the competitive binding assay, R(-)DMCPG (Ki=763.75 nmol/L) was 4-and 2-fold more potent than (±)DMCPG (Ki=3186 nmol/L) and S(+)DMCPG (Ki= 1699 nmol/L) in inhibiting the binding of [3H]QNB. The R(-) and S (+) configurations showed positive cooperation (nH>1) with the muscarinic receptor, whereas (±)DMCPG had a negative cooperation (nH<1) relationship with the muscarinic receptor in a radio-binding assay. Both the R(-) and S(+) configurations could potentiate the effect of sub-threshold hypnotic dose of sodium pentobarbital in a dose-dependent manner (the ED50 values were 2.53 and 18.65 mg/kg, respectively),but (±)DMCPG did not display significant central depressant effects at doses from 10 to 29.15 mg/kg (P>0.05). (±)DMCPG and its optical isomers suppressed the guinea pig ileum contractile response to carbachol. The IC50 values were 7.78×10-9,1.88×10-7, and 1.03× 10-7 nmol/L, respectively. In the anti-salivation study,(±)DMCPG and its enantiomers depressed oxotremorine- induced salivation in a dose-dependent manner, and the order of potency was R(-)DMCPG (ED50=0.44 mg/kg)>(±)DMCPG (ED50

  13. In Vivo Effects of Free Form Astaxanthin Powder on Anti-Oxidation and Lipid Metabolism with High-Cholesterol Diet.

    Science.gov (United States)

    Chen, Yung-Yi; Lee, Pei-Chi; Wu, Yi-Long; Liu, Li-Yun

    2015-01-01

    Astaxanthin extracted from Pomacea canaliculata eggs was made into free-form astaxanthin powder (FFAP) and its effects on lipid metabolism, liver function, antioxidants activities and astaxanthin absorption rate were investigated. 45 hamsters were split into 5 groups and fed with normal diet, high-cholesterol control (0.2% cholesterol), 1.6FFAP (control+1.6% FFAP), 3.2FFAP (control+3.2% FFAP) and 8.0FFAP (control+8.0% FFAP), respectively, for 6 weeks. FFAP diets significantly decreased the liver total cholesterol, triglyceride levels and increased liver fatty acids (C20:5n3; C22:6n3) compositions. It decreased plasma alanine aminotransferase and aspartate aminotransferase. In terms of anti-oxidative activities, we found 8.0 FFAP diet significantly decreased plasma and liver malonaldehyde (4.96±1.96 μg TEP eq./mL and 1.56±0.38 μg TEP eq./g liver) and liver 8-isoprostane levels (41.48±13.69 μg 8-ISOP/g liver). On the other hand, it significantly increased liver catalase activity (149.10±10.76 μmol/min/g liver), Vitamin C (2082.97±142.23 μg/g liver), Vitamin E (411.32±81.67 μg/g liver) contents, and glutathione levels (2.13±0.42 mg GSH eq./g liver). Furthermore, 80% of astaxanthin absorption rates in all FFAP diet groups suggest FFAP is an effective form in astaxanthin absorption. Finally, astaxanthin was found to re-distribute to the liver and eyes in a dose dependent manner. Taken together, our results suggested that the appropriate addition of FFAP into high cholesterol diets increases liver anti-oxidative activity and reduces the concentration of lipid peroxidase and therefore, it may be beneficial as a material in developing healthy food.

  14. In Vivo Effects of Free Form Astaxanthin Powder on Anti-Oxidation and Lipid Metabolism with High-Cholesterol Diet.

    Directory of Open Access Journals (Sweden)

    Yung-Yi Chen

    Full Text Available Astaxanthin extracted from Pomacea canaliculata eggs was made into free-form astaxanthin powder (FFAP and its effects on lipid metabolism, liver function, antioxidants activities and astaxanthin absorption rate were investigated. 45 hamsters were split into 5 groups and fed with normal diet, high-cholesterol control (0.2% cholesterol, 1.6FFAP (control+1.6% FFAP, 3.2FFAP (control+3.2% FFAP and 8.0FFAP (control+8.0% FFAP, respectively, for 6 weeks. FFAP diets significantly decreased the liver total cholesterol, triglyceride levels and increased liver fatty acids (C20:5n3; C22:6n3 compositions. It decreased plasma alanine aminotransferase and aspartate aminotransferase. In terms of anti-oxidative activities, we found 8.0 FFAP diet significantly decreased plasma and liver malonaldehyde (4.96±1.96 μg TEP eq./mL and 1.56±0.38 μg TEP eq./g liver and liver 8-isoprostane levels (41.48±13.69 μg 8-ISOP/g liver. On the other hand, it significantly increased liver catalase activity (149.10±10.76 μmol/min/g liver, Vitamin C (2082.97±142.23 μg/g liver, Vitamin E (411.32±81.67 μg/g liver contents, and glutathione levels (2.13±0.42 mg GSH eq./g liver. Furthermore, 80% of astaxanthin absorption rates in all FFAP diet groups suggest FFAP is an effective form in astaxanthin absorption. Finally, astaxanthin was found to re-distribute to the liver and eyes in a dose dependent manner. Taken together, our results suggested that the appropriate addition of FFAP into high cholesterol diets increases liver anti-oxidative activity and reduces the concentration of lipid peroxidase and therefore, it may be beneficial as a material in developing healthy food.

  15. Consistent Chiral Kinetic Theory in Weyl Materials: Chiral Magnetic Plasmons

    Science.gov (United States)

    Gorbar, E. V.; Miransky, V. A.; Shovkovy, I. A.; Sukhachov, P. O.

    2017-03-01

    We argue that the correct definition of the electric current in the chiral kinetic theory for Weyl materials should include the Chern-Simons contribution that makes the theory consistent with the local conservation of the electric charge in electromagnetic and strain-induced pseudoelectromagnetic fields. By making use of such a kinetic theory, we study the plasma frequencies of collective modes in Weyl materials in constant magnetic and pseudomagnetic fields, taking into account the effects of dynamical electromagnetism. We show that the collective modes are chiral plasmons. While the plasma frequency of the longitudinal collective mode coincides with the Langmuir one, this mode is unusual because it is characterized not only by oscillations of the electric current density, but also by oscillations of the chiral current density. The latter are triggered by a dynamical version of the chiral electric separation effect. We also find that the plasma frequencies of the transverse modes split up in a magnetic field. This finding suggests an efficient means of extracting the chiral shift parameter from the measurement of the plasma frequencies in Weyl materials.

  16. Can a Non-Chiral Object Be Made of Two Identical Chiral Moieties?

    Science.gov (United States)

    LeMarechal, Jean Francois

    2008-01-01

    Several pedagogical objects can be used to discuss chirality. Here, we use the cut of an apple to show that the association of identical chiral moieties can form a non-chiral object. Octahedral chirality is used to find situations equivalent to the cut of the apple. (Contains 5 figures.)

  17. An Inherent Chiral Calix[4]arene Bearing Chiral Groups without Forming Sub-ring

    Institute of Scientific and Technical Information of China (English)

    Xian Xian LIU; Yan Song ZHENG; Wan Ling MO

    2006-01-01

    The NMR spectra revealed that the calixarene frame of 1, 3-disubstituted calix[4]arenes bearing optically active groups is asymmetric, even without the formation of a sub-ring. This inherent chirality arises from the interaction of the two chiral groups, which hinder the substituents' free rotation. Thus, these chiral calix[4]arenes display good chiral recognition ability.

  18. Chaos of chiral condensate

    CERN Document Server

    Hashimoto, Koji; Yoshida, Kentaroh

    2016-01-01

    Assigning a chaos index for vacua of generic quantum field theories is a challenging problem. We find chaotic behavior of chiral condensates of a quantum gauge theory at strong coupling limit, by using the AdS/CFT correspondence. We evaluate the time evolution of homogeneous quark condensates and in an N=2 supersymmetric QCD with the SU(N_c) gauge group at large N_c and at large 't Hooft coupling lambda. At an equivalent classical gravity picture, a Lyapunov exponent is readily defined. We show that the condensates exhibit chaotic behavior for energy density E > (6x10^2) (N_c/lambda^2) (m_q)^4 where m_q is the quark mass. The energy region of the chaotic vacua of the N=2 supersymmetric QCD increases for smaller N_c or larger lambda. The Lyapunov exponent is calculated as a function of the theory (N_c,lambda,E), showing that the N=2 supersymmetric QCD is more chaotic for smaller N_c.

  19. Extraction and purification of high-value metabolites from microalgae: essential lipids, astaxanthin and phycobiliproteins.

    Science.gov (United States)

    Cuellar-Bermudez, Sara P; Aguilar-Hernandez, Iris; Cardenas-Chavez, Diana L; Ornelas-Soto, Nancy; Romero-Ogawa, Miguel A; Parra-Saldivar, Roberto

    2015-03-01

    The marked trend and consumers growing interest in natural and healthy products have forced researches and industry to develop novel products with functional ingredients. Microalgae have been recognized as source of functional ingredients with positive health effects since these microorganisms produce polyunsaturated fatty acids, polysaccharides, natural pigments, essential minerals, vitamins, enzymes and bioactive peptides. For this reason, the manuscript reviews two of the main high-value metabolites which can be obtained from microalgae: pigments and essential lipids. Therefore, the extraction and purification methods for polyunsaturated fatty acids, astaxanthin, phycoerythrin and phycocyanin are described. Also, the effect that environmental growth conditions have in the production of these metabolites is described. This review summarizes the existing methods to extract and purify such metabolites in order to develop a feasible and sustainable algae industry.

  20. Oil bodies as a potential microencapsulation carrier for astaxanthin stabilisation and safe delivery.

    Science.gov (United States)

    Acevedo, Francisca; Rubilar, Mónica; Jofré, Ignacio; Villarroel, Mario; Navarrete, Patricia; Esparza, Magdalena; Romero, Fernando; Vilches, Elías Alberto; Acevedo, Valentina; Shene, Carolina

    2014-01-01

    Astaxanthin (AST) is a valued molecule because of its high antioxidant properties. However, AST is extremely sensitive to oxidation, causing the loss of its bioactive properties. The purposes of this study were to define conditions for microencapsulating AST in oil bodies (OB) from Brassica napus to enhance its oxidative stability, and to test the bioactivity of the microencapsulated AST (AST-M) in cells. Conditions for maximising microencapsulation efficiency (ME) were determined using the Response Surface Methodology, obtaining a high ME (>99%). OB loaded with AST showed a strong electrostatic repulsion in a wide range of pH and ionic strengths. It was found that AST-M exposed to air and light was more stable than free AST. In addition, the protective effect of AST against intracellular ROS production was positively influenced by microencapsulation in OB. These results suggest that OB offer a novel option for stabilising and delivering AST.

  1. Bistable aggregate of all-trans-astaxanthin in an aqueous solution

    Science.gov (United States)

    Mori, Yuso; Yamano, Kuniko; Hashimoto, Hideki

    1996-05-01

    The temperature dependence of the optical absorption spectra for astaxanthin aggregate has been studied between 2 and 32°C. Red-shifted absorption bands as compared to the monomer absorption band are found above 21°C in addition to the blue-shifted band of the aggregate. The spectra suggest that the molecular arrangement in the aggregate is a bistable one consisting of head-to-tail and card-packed arrangements. A diagram describing the bistability together with the monomer state is proposed in the space defined by the free energy and the quantity of Σi = 1 N< θ12 + < σθ12 for the ith molecule in the N-molecule aggregate.

  2. Excited state properties of the astaxanthin radical cation: A quantum chemical study

    Science.gov (United States)

    Dreuw, Andreas; Starcke, Jan Hendrik; Wachtveitl, Josef

    2010-07-01

    Using time-dependent density functional theory, the excited electronic states of the astaxanthin radical cation (AXT rad + ) are investigated. While the optically allowed excited D 1 and D 3 states are typical ππ∗ excited states, the D 2 and D 4 states are nπ∗ states. Special emphasis is put onto the influence of the carbonyl groups onto the excited states. For this objective, the excited states of four hypothetical carotenoids and zeaxanthin have been computed. Addition of a carbonyl group to a conjugated carbon double bond system does essentially not change the vertical excitation energies of the optically allowed ππ∗ states due to two counter-acting effects: the excitation energy should increase due to the -M-effect of the carbonyl group and at the same time decrease owing to the elongation of the conjugated double bond system by the carbonyl group itself.

  3. The Metal Cation Chelating Capacity of Astaxanthin. Does This Have Any Influence on Antiradical Activity?

    Directory of Open Access Journals (Sweden)

    Ana Martínez

    2012-01-01

    Full Text Available In this Density Functional Theory study, it became apparent that astaxanthin (ASTA may form metal ion complexes with metal cations such as Ca+2, Cu+2, Pb+2, Zn+2, Cd+2 and Hg+2. The presence of metal cations induces changes in the maximum absorption bands which are red shifted in all cases. Therefore, in the case of compounds where metal ions are interacting with ASTA, they are redder in color. Moreover, the antiradical capacity of some ASTA-metal cationic complexes was studied by assessing their vertical ionization energy and vertical electron affinity, reaching the conclusion that metal complexes are slightly better electron donors and better electron acceptors than ASTA.

  4. Excited state properties of the astaxanthin radical cation: A quantum chemical study

    Energy Technology Data Exchange (ETDEWEB)

    Dreuw, Andreas, E-mail: andreas.dreuw@theochem.uni-frankfurt.de [Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max von Laue-Str. 7, 60438 Frankfurt am Main (Germany); Starcke, Jan Hendrik; Wachtveitl, Josef [Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max von Laue-Str. 7, 60438 Frankfurt am Main (Germany)

    2010-07-19

    Using time-dependent density functional theory, the excited electronic states of the astaxanthin radical cation (AXT{sup {center_dot}+}) are investigated. While the optically allowed excited D{sub 1} and D{sub 3} states are typical {pi}{pi}* excited states, the D{sub 2} and D{sub 4} states are n{pi}* states. Special emphasis is put onto the influence of the carbonyl groups onto the excited states. For this objective, the excited states of four hypothetical carotenoids and zeaxanthin have been computed. Addition of a carbonyl group to a conjugated carbon double bond system does essentially not change the vertical excitation energies of the optically allowed {pi}{pi}* states due to two counter-acting effects: the excitation energy should increase due to the -M-effect of the carbonyl group and at the same time decrease owing to the elongation of the conjugated double bond system by the carbonyl group itself.

  5. Crystallisation of alpha-crustacyanin, the lobster carapace astaxanthin-protein: results from EURECA

    Science.gov (United States)

    Zagalsky, P. F.; Wright, C. E.; Parsons, M.

    1995-08-01

    Crystallisation of alpha-crustacyanin, the lobster carapace astaxanthin-protein was attempted under microgravity conditions in EURECA satellite using liquid-liquid diffusion with polyethyleneglycol (PEG) as precipitant; in a second reaction chamber phenol and dioxan were used as additives to prevent composite crystal growth. Crystals of alpha-crustacyanin grown under microgravity from PEG were larger than those grown terrestrially in the same apparatus under otherwise identical conditions. On retrieval, the crystals from PEG were shown to be composite and gave a powder diffraction pattern. The second reaction chamber showed leakage on retrieval and had also been subjected to rapid temperature variation during flight. Crystal fragments were nevertheless recovered but showed a powder diffraction pattern. It is concluded, certainly for liquid-liquid diffusion using PEG alone, that, for crustacyanin, although microgravity conditions resulted in an increase in dimensions of crystals, a measurable improvement in molecular ordering was not achieved.

  6. Excited states and electrochromism of radical cation of the carotenoid astaxanthin

    Science.gov (United States)

    Krawczyk, Stanisław

    1998-09-01

    Radical cations of the carotenoid astaxanthin were generated by chemical oxidation with Fe(Cl) 3, and their absorption and electroabsorption (Stark) spectra at temperatures about 150 K were recorded in the spectral range from 5900 to 26000 cm -1 (380 to 1700 nm), covering two absorptive electronic transitions from D 0 (ground) to D 1 and D 2 excited states. The changes in static polarizability are negative and equal -40±10 A 3 for D 0→D 1 and -105±15 A 3 for D 0→D 2, pointing that dominant contribution to polarizabilities results from the coupling of D 1 and D 2 with the ground state. An approximate localization of the next excited state with ground-state parity is estimated based on arguments from perturbation theory.

  7. Extraction and purification of high-value metabolites from microalgae: essential lipids, astaxanthin and phycobiliproteins

    Science.gov (United States)

    Cuellar-Bermudez, Sara P; Aguilar-Hernandez, Iris; Cardenas-Chavez, Diana L; Ornelas-Soto, Nancy; Romero-Ogawa, Miguel A; Parra-Saldivar, Roberto

    2015-01-01

    The marked trend and consumers growing interest in natural and healthy products have forced researches and industry to develop novel products with functional ingredients. Microalgae have been recognized as source of functional ingredients with positive health effects since these microorganisms produce polyunsaturated fatty acids, polysaccharides, natural pigments, essential minerals, vitamins, enzymes and bioactive peptides. For this reason, the manuscript reviews two of the main high-value metabolites which can be obtained from microalgae: pigments and essential lipids. Therefore, the extraction and purification methods for polyunsaturated fatty acids, astaxanthin, phycoerythrin and phycocyanin are described. Also, the effect that environmental growth conditions have in the production of these metabolites is described. This review summarizes the existing methods to extract and purify such metabolites in order to develop a feasible and sustainable algae industry. PMID:25223877

  8. Process design and economic evaluation of green extraction methods for recovery of astaxanthin from shrimp waste

    DEFF Research Database (Denmark)

    Razi Parjikolaei, Behnaz; Errico, Massimiliano; El-Houri, Rime Bahij

    2017-01-01

    Sunflower oil (SF) and its methyl ester as well as supercritical fluid (SC-CO2+ 5 wt% EtOH) have recently been shown as potential green solvents which could substitute traditional organic solvents. This study investigates the economic feasibility of using these green solvents to extract astaxanthin...... (ASX) from shrimp processing waste. The feasibility of commercial use of the green solvents under plausible process conditions is compared to extraction with a mixture of hexane: isopropanol (Hex:IPA). The process flowsheets describing these processes were modelled by means of SuperPro Designer...... with SF and synthetic ASX yielded a shrimp feed production cost comparable to the current market price. The calculated feed price based on the ASX production cost of the other green processes, ME-SF and SCFE, resulted in a significantly higher production cost....

  9. Chiral Thirring–Wess model

    Energy Technology Data Exchange (ETDEWEB)

    Rahaman, Anisur, E-mail: anisur.rahman@saha.ac.in

    2015-10-15

    The vector type of interaction of the Thirring–Wess model was replaced by the chiral type and a new model was presented which was termed as chiral Thirring–Wess model in Rahaman (2015). The model was studied there with a Faddeevian class of regularization. Few ambiguity parameters were allowed there with the apprehension that unitarity might be threatened like the chiral generation of the Schwinger model. In the present work it has been shown that no counter term containing the regularization ambiguity is needed for this model to be physically sensible. So the chiral Thirring–Wess model is studied here without the presence of any ambiguity parameter and it has been found that the model not only remains exactly solvable but also does not lose the unitarity like the chiral generation of the Schwinger model. The phase space structure and the theoretical spectrum of this new model have been determined in the present scenario. The theoretical spectrum is found to contain a massive boson with ambiguity free mass and a massless boson.

  10. Chiral Logs in Quenched QCD

    CERN Document Server

    Dong, S J; Horváth, I; Lee, F X; Liu, K F; Mathur, N; Zhang, J B

    2003-01-01

    The quenched chiral logs are examined on a $16^3 \\times 28$ lattice with Iwasaki gauge action and overlap fermions. The pion decay constant $f_{\\pi}$ is used to set the lattice spacing, $a = 0.200(3)$ fm. With pion mass as low as $\\sim 180 {\\rm MeV}$, we see the quenched chiral logs clearly in $m_{\\pi}^2/m$ and $f_P$, the pseudoscalar decay constant. We analyze the data to determine how low the pion mass needs to be in order for the quenched one-loop chiral perturbation theory ($\\chi$PT) to apply. With the constrained curve fitting, we are able to extract the quenched chiral log parameter $\\delta$ together with the chiral cutoff $\\Lambda_{\\chi}$ and other parameters. Only for $m_{\\pi} \\leq 300 {\\rm MeV}$ do we obtain a consistent and stable fit with a constant $\\delta$ which we determine to be 0.23(2). By comparing to the $12^3 \\times 28$ lattice, we estimate the finite volume effect to be about 1.8% for the smallest pion mass. We also study the quenched non-analytic terms in the nucleon and the $\\rho$ masses...

  11. Orientation-dependent handedness and chiral design

    OpenAIRE

    Efrati, Efi; Irvine, William T. M.

    2013-01-01

    Chirality occupies a central role in fields ranging from biological self-assembly to the design of optical metamaterials. The definition of chirality, as given by Lord Kelvin, associates chirality with the lack of mirror symmetry: the inability to superpose an object on its mirror image. While this definition has guided the classification of chiral objects for over a century, the quantification of handed phenomena based on this definition has proven elusive, if not impossible, as manifest in ...

  12. Chiral Decomposition For Non-Abelian Bosons

    CERN Document Server

    Braga, N R F; Braga, Nelson R. F.; Wotzasek, Clovis

    1996-01-01

    We study the non-abelian extension for the splitting of a scalar field into chiral components. Using this procedure we find a non ambiguous way of coupling a non abelian chiral scalar field to gravity. We start with a (non-chiral) WZW model covariantly coupled to a background metric and, after the splitting, arrive at two chiral Wess-Zumino-Witten (WZW) models coupled to gravity.

  13. Chiral gap effect in curved space

    CERN Document Server

    Flachi, Antonino

    2014-01-01

    We discuss a new type of QCD phenomenon induced in curved space. In the QCD vacuum a mass gap of Dirac fermions is attributed to the spontaneous breaking of chiral symmetry. If the curvature is positive large, the chiral condensate melts but a chiral invariant mass gap can still remain, which we name the chiral gap effect in curved space. This leads to decoupling of quark deconfinement which implies a view of black holes surrounded by a first-order QCD phase transition.

  14. Chirality: a relational geometric-physical property.

    Science.gov (United States)

    Gerlach, Hans

    2013-11-01

    The definition of the term chirality by Lord Kelvin in 1893 and 1904 is analyzed by taking crystallography at that time into account. This shows clearly that chirality is a relational geometric-physical property, i.e., two relations between isometric objects are possible: homochiral or heterochiral. In scientific articles the relational term chirality is often mistaken for the two valued measure for the individual (absolute) sense of chirality, an arbitrary attributive term.

  15. Bifurcated, modular syntheses of chiral annulet triazacyclononanes.

    Science.gov (United States)

    Argouarch, Gilles; Stones, Graham; Gibson, Colin L; Kennedy, Alan R; Sherrington, David C

    2003-12-21

    Three chiral 2,6-disubstituted tri-N-methyl azamacrocycles have been prepared by modular methods. These macrocycles were accessed from three chiral 1,4,7-triazaheptanes intermediates that were prepared by two independent routes. The first of these routes involved the benzylamine opening of chiral tosyl aziridines followed by debenzylation but was problematic on solubility grounds. A second, more effective, route was developed which avoided debenzylation by using ammonia in the nucleophilic opening of chiral tosyl aziridines.

  16. On the Biological Advantage of Chirality

    OpenAIRE

    1999-01-01

    The presence of chirality in the main molecules of life may well be not just a structural artifact, but of pure biological advantage. The possibility of the existence of a phenomenon of a special mode of interaction, labeled as "chiral interaction" (CI), for which structural chirality is a necessary condition, is the main reason for such an advantage. In order to demonstrate such a possibility, macroscopic chiral devices are introduced and presented as analogies for such an interaction. For t...

  17. Astaxanthin from Crayfish (Procambarus clarkii as a Pigmentary Ingredient in the Feed of Laying Hens

    Directory of Open Access Journals (Sweden)

    Garrido-Fernández, J.

    2008-06-01

    Full Text Available Chicken egg yolks generally owe their color to yellow carotenoids. The addition of synthetic red pigments allows changes in color, from the original yellow to red hues which may be more appealing to consumers in certain markets.Our aim has been to test whether ground crayfish shells, which are a rich and natural source of astaxanthin, produce detectable changes in the coloration of egg yolks through the accumulation of this carotenoid. Laying hens were fed with a commercial feed mixed with crayfish powder and the carotenoid profiles of the yolks in the eggs laid during the trial were monitored by HPLC. The analyses showed a progressive increase in the astaxanthin concentration in the egg yolks, reaching similar levels to those obtained for the rest of present carotenoid pigments.La yema de huevo de gallina debe su coloración a la presencia de carotenoides de tonalidad amarilla. La adición de colorantes sintéticos de tonalidades rojas permite modificar e incrementar la coloración de la yema desde el amarillo original a tonos rojos que pueden ser demandados en ciertos mercados según las preferencias del consumidor. El objetivo del trabajo fue probar si un triturado obtenido a partir de caparazones de cangrejo, que es una fuente natural y rica en astaxanteno, produce cambios detectables en la coloración de la yema de huevo por la acumulación de dicho carotenoide. Las gallinas ponedoras se alimentaron con un pienso comercial al que se adicionó triturado de caparazón de cangrejo. Se realizó un seguimiento de los cambios en la composición carotenoide (mediante HPLC de la yema de los huevos puestos durante el periodo de alimentación suplementada. Los análisis mostraron una progresiva incorporación de astaxanteno que alcanzó niveles similares al resto de carotenoides presentes inicialmente en la yema.

  18. Field induced spin chirality and chirality switching in magnetic multilayers

    Science.gov (United States)

    Tartakovskaya, Elena V.

    2015-05-01

    The physical origin of the field-induced spin chirality experimentally observed in rare earth multilayers is determined. It is shown that the effect is possible due to the interplay between solid-state exchange interactions (the Ruderman-Kittel-Kasuya-Yosida and the Dsyaloshinsky-Moriya interactions), the external magnetic field and a special confinement of magnetic constituents. The presented model describes a certain temperature dependence of the chirality factor in agreement with experimental data and opens a new way to design nanostructured objects with predicted handedness.

  19. Chiral dynamics of baryons in the perturbative chiral quark model

    Energy Technology Data Exchange (ETDEWEB)

    Pumsa-ard, K.

    2006-07-01

    In this work we develop and apply variants of a perturbative chiral quark model (PCQM) to the study of baryonic properties dominantly in the low-energy region. In a first step we consider a noncovariant form of the PCQM, where confinement is modelled by a static, effective potential and chiral corrections are treated to second order, in line with similar chiral quark models. We apply the PCQM to the study of the electromagnetic form factors of the baryon octet. We focus in particular on the low-energy observables such as the magnetic moments, the charge and magnetic radii. In addition, the electromagnetic N-delta transition is also studied in the framework of the PCQM. In the chiral loop calculations we consider a quark propagator, which is restricted to the quark ground state, or in hadronic language to nucleon and delta intermediate states, for simplicity. We furthermore include the low-lying excited states to the quark propagator. In particular, the charge radius of the neutron and the transverse helicity amplitudes of the N-delta transition are considerably improved by this additional effect. In a next step we develop a manifestly Lorentz covariant version of the PCQM, where in addition higher order chiral corrections are included. The full chiral quark Lagrangian is motivated by and in analogy to the one of Chiral Perturbation Theory (ChPT). This Lagrangian contains a set of low energy constants (LECs), which are parameters encoding short distance effects and heavy degrees of freedom. We evaluate the chiral Lagrangian to order O(p{sup 4}) and to one loop to generate the dressing of the bare quark operators by pseudoscalar mesons. In addition we include the vector meson degrees of freedom in our study. Projection of the dressed quark operators on the baryonic level serves to calculate the relevant matrix elements. In a first application of this scheme, we resort to a parameterization of the valence quark form factors in the electromagnetic sector. Constraints

  20. Features of Astaxanthin and Its Application Prospects%虾青素的特性及应用前景

    Institute of Scientific and Technical Information of China (English)

    肖素荣; 李京东

    2011-01-01

    As a kind of material with special physiological function, astaxanthin has broad prospects in the industries of food,medicine, and cosmetics due to its antioxidant and pigmentation ability.This paper mainly discussed astaxanthin's structural features,physical and chemical properties, biological functions, and its application prospects.%虾青素作为一种具有特殊生理功效的物质,其抗氧化作用和着色作用在食品、药品、饲料以及化妆品行业具有广阔前景.文章主要论述了虾青素的结构特点、理化特性、生物学功效及应用.

  1. Biological variation of lipid constituents and distribution of tocopherols and astaxanthin in farmed Atlantic salmon (Salmo salar)

    DEFF Research Database (Denmark)

    Refsgaard, Hanne; Brockhoff, Per B; Jensen, Benny

    1998-01-01

    The contents of fat, astaxanthin, and tocogherols and the fatty acid composition of a homogeneous group of 145 farmed Atlantic salmon (Salmo salar) were determined. The analytical variation of the data was stastistically-separated from the biological variation. The fat content in the muscle near....... The concentrations of alpha-, gamma-, and delta-tocopherols were approximately 32, 2.9, and 0.4 mg/kg of muscle, respectively, and the biological standard deviations were 4.5, 0.4, and 0.07 mg/kg (14, 14, and 20%), respectively. in another group of five salmon the distributions throughout the fillet were determined......, longitudinally as well as transversally. The distribution of fat, astaxanthin, and tocopherols varied throughout the salmon. The fatty acid composition varied little between extracts from different locations of the fillet...

  2. Effect of astaxanthin and cholesterol on growth, survival, and pigmentation of adult spiny lobster, Panulirus ornatus (Decapoda, Palinuridae

    Directory of Open Access Journals (Sweden)

    Lai V. Hung

    2010-11-01

    Full Text Available Prior research on the spiny lobster Panulirus ornatus (Fabricius, 1798 determined thatintermediate levels of cholesterol are important in diets, but astaxanthin may not be. Here we examinedhow the growth, survival and coloration of spiny lobster were influenced by the inclusion of bothastaxanthin (50, 60 and 70 mg.kg-1 and cholesterol (0.3, 0.4 and 0.5 % in a two factor experiment.Overall, survival was 84.8% with no significant difference among dietary treatments. Lobsters grew thebest when fed the diet containing the lowest cholesterol and greatest astaxanthin of the levels presented.The results of this study point out the need to examine the effects of dietary component addition acrossa range of inclusion levels simultaneously for multiple nutrients.

  3. Analysis and identification of astaxanthin and its carotenoid precursors from Xanthophyllomyces dendrorhous by high-performance liquid chromatography.

    Science.gov (United States)

    Lu, Mingbo; Zhang, Yang'e; Zhao, Chunfang; Zhou, Pengpeng; Yu, Longjiang

    2010-01-01

    This study presents an HPLC method for simultaneous analysis of astaxanthin and its carotenoid precursors from Xanthophyllomyces dendrorhous. The HPLC method is accomplished by employing a C18 column and the mobile phase methanol/water/acetonitrile/ dichloromethane (70:4:13:13, v/v/v/v). Astaxanthin is quantified by detection at 480 nm. The carotenoid precursors are identified by LC-APCI-MS and UV-vis absorption spectra. Peaks showed in the HPLC chromatogram are identified as carotenoids in the monocyclic biosynthetic pathway or their derivatives. In the monocyclic carotenoid pathway, 3,3'-dihydroxy-beta,psi-carotene-4,4'-dione (DCD) is produced through gamma-carotene and torulene.

  4. Neutrino Oscillation Induced by Chiral Phase Transition

    Institute of Scientific and Technical Information of China (English)

    MU Cheng-Fu; SUN Gao-Feng; ZHUANG Peng-Fei

    2009-01-01

    Electric charge neutrality provides a relationship between chiral dynamics and neutrino propagation in compact stars.Due to the sudden drop of the electron density at the first-order chiral phase transition,the oscillation for low energy neutrinos is significant and can be regarded as a signature of chiral symmetry restoration in the core of compact stars.

  5. Quenched Chiral Perturbation Theory to one loop

    NARCIS (Netherlands)

    Colangelo, G.; Pallante, E.

    1998-01-01

    The divergences of the generating functional of quenched Chiral Perturbation theory (qCHPT) to one loop are computed in closed form. We show how the quenched chiral logarithms can be reabsorbed in the renormalization of the B0 parameter of the leading order Lagrangian. Finally, we do the chiral powe

  6. Shear Viscosity of Turbulent Chiral Plasma

    CERN Document Server

    Kumar, Avdhesh; Das, Amita; Kaw, P K

    2016-01-01

    It is well known that the difference between the chemical potentials of left-handed and right-handed particles in a parity violating (chiral) plasma can lead to an instability. We show that the chiral instability may drive turbulent transport. Further we estimate the anomalous viscosity of chiral plasma arising from the enhanced collisionality due to turbulence.

  7. Exact Chiral Symmetry on the Lattice

    CERN Document Server

    Neuberger, H

    2001-01-01

    Developments during the last eight years have refuted the folklore that chiral symmetries cannot be preserved on the lattice. The mechanism that permits chiral symmetry to coexist with the lattice is quite general and may work in Nature as well. The reconciliation between chiral symmetry and the lattice is likely to revolutionize the field of numerical QCD.

  8. Direct observation of long-lived isomers in $^{212}$Bi

    CERN Document Server

    Chen, L; Geissel, H; Litvinov, Yu A; Beckert, K; Beller, P; Bosch, F; Boutin, D; Caceres, L; Carroll, J J; Cullen, D M; Cullen, I J; Franzke, B; Gerl, J; Górska, M; Jones, G A; Kishada, A; Knöbel, R; Kozhuharov, C; Kurcewicz, J; Litvinov, S A; Liu, Z; Mandal, S; Montes, F; Münzenberg, G; Nolden, F; Ohtsubo, T; Patyk, Z; Plaß, W R; Podolyák, Zs; Rigby, S; Saito, N; Saito, T; Scheidenberger, C; Simpson, E C; Shindo, M; Steck, M; Sun, B; Williams, S J; Weick, H; Winkler, M; Wollersheim, H -J; Yamaguchi, T

    2013-01-01

    Long-lived isomers in 212Bi have been studied following 238U projectile fragmentation at 670 MeV per nucleon. The fragmentation products were injected as highly charged ions into the GSI storage ring, giving access to masses and half-lives. While the excitation energy of the first isomer of 212Bi was confirmed, the second isomer was observed at 1478(30) keV, in contrast to the previously accepted value of >1910 keV. It was also found to have an extended Lorentz-corrected in-ring halflife >30 min, compared to 7.0(3) min for the neutral atom. Both the energy and half-life differences can be understood as being due a substantial, though previously unrecognised, internal decay branch for neutral atoms. Earlier shell-model calculations are now found to give good agreement with the isomer excitation energy. Furthermore, these and new calculations predict the existence of states at slightly higher energy that could facilitate isomer de-excitation studies.

  9. A new high-spin isomer in {sup 195}Bi

    Energy Technology Data Exchange (ETDEWEB)

    Roy, T.; Mukherjee, G.; Rana, T.K.; Bhattacharya, Soumik; Asgar, Md.A.; Bhattacharya, C.; Bhattacharya, S.; Bhattacharyya, S.; Pai, H. [Variable Energy Cyclotron Centre, Kolkata (India); Madhavan, N.; Bala, I.; Gehlot, J.; Gurjar, R.K.; Jhingan, A.; Kumar, R.; Muralithar, S.; Nath, S.; Singh, R.P.; Varughese, T. [Inter University Acclerator Centre, New Delhi (India); Basu, K.; Bhattacharjee, S.S.; Ghugre, S.S.; Raut, R.; Sinha, A.K. [UGC-DAE-CSR Kolkata Centre, Kolkata (India); Palit, R. [Tata Institute of Fundamental Research, Department of Nuclear and Atomic Physics, Mumbai (India)

    2015-11-15

    A new high-spin isomer has been identified in {sup 195}Bi at the focal plane of the HYbrid Recoil mass Analyser (HYRA) used in the gas-filled mode. The fusion evaporation reactions {sup 169}Tm ({sup 30}Si, x n) {sup 193,} {sup 195}Bi were used with the beam energies on targets of 168 and 146MeV for 6n and 4n channels, respectively. The evaporation residues, separated from the fission fragments, and their decays were detected at the focal plane of HYRA using MWPC, Si-Pad and clover HPGe detectors. The half-life of the new isomer in {sup 195}Bi has been measured to be 1.6(1) μs. The configuration of the new isomer has been proposed and compared with the other isomers in this region. The Total Routhian Surface (TRS) calculations for the three-quasiparticle configurations corresponding to the new isomer suggest an oblate deformation for this isomeric state. The same calculations for different configurations in {sup 195}Bi and for the even-even {sup 194}Pb core indicate that the proton i{sub 13/2} orbital has a large shape driving effect towards oblate shape in these nuclei. (orig.)

  10. Effects of temperature on the astaxanthin productivity and light harvesting characteristics of the green alga Haematococcus pluvialis.

    Science.gov (United States)

    Giannelli, Luca; Yamada, Hiroyuki; Katsuda, Tomohisa; Yamaji, Hideki

    2015-03-01

    The green alga Haematococcus pluvialis, which accumulates astaxanthin at an optimal temperature of 20°C, was cultivated under temperatures of 20°C, 23.5°C, 27°C, and 30.5°C, in order to assess the effects on algal metabolism during the growth phase. The culture growth rate declined with above-optimal increases in temperature, and the final maximum cell concentration at 30.5°C reached only 35% of that attained at 20°C. On the contrary, the biomass productivity was increased under all the high-temperature conditions, probably reflecting the metabolism switch from cell duplication to energy accumulation that is typically observed in algal cultures subjected to environmental stress. Moreover, an increase in the light-harvesting capability of the alga was observed by means of the total pigment balance and the photosynthesis-intensity (PI) curve measured under the different cultivation conditions. Cultures kept at higher temperatures were able to better harvest and utilize the impinging light due to photo-acclimation. Finally, the differences in the astaxanthin metabolism were elucidated by subjecting the cultures to nitrogen starvation at 20°C and 27°C. In the culture at 27°C, a 1.4-fold increase in the astaxanthin productivity was observed when compared to that at 20°C, and the latter required almost two-fold more energy for the astaxanthin production compared with the 27°C culture.

  11. Astaxanthin vs placebo on arterial stiffness, oxidative stress and inflammation in renal transplant patients (Xanthin: a randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Robertson Iain K

    2008-12-01

    Full Text Available Abstract Background There is evidence that renal transplant recipients have accelerated atherosclerosis manifest by increased cardiovascular morbidity and mortality. The high incidence of atherosclerosis is, in part, related to increased arterial stiffness, vascular dysfunction, elevated oxidative stress and inflammation associated with immunosuppressive therapy. The dietary supplement astaxanthin has shown promise as an antioxidant and anti-inflammatory therapeutic agent in cardiovascular disease. The aim of this trial is to investigate the effects of astaxanthin supplementation on arterial stiffness, oxidative stress and inflammation in renal transplant patients. Method and Design This is a randomised, placebo controlled clinical trial. A total of 66 renal transplant recipients will be enrolled and allocated to receive either 12 mg/day of astaxanthin or an identical placebo for one-year. Patients will be stratified into four groups according to the type of immunosuppressant therapy they receive: 1 cyclosporine, 2 sirolimus, 3 tacrolimus or 4 prednisolone+/-azathioprine, mycophenolate mofetil or mycophenolate sodium. Primary outcome measures will be changes in 1 arterial stiffness measured by aortic pulse wave velocity (PWV, 2 oxidative stress assessed by plasma isoprostanes and 3 inflammation by plasma pentraxin 3. Secondary outcomes will include changes in vascular function assessed using the brachial artery reactivity (BAR technique, carotid artery intimal medial thickness (CIMT, augmentation index (AIx, left ventricular afterload and additional measures of oxidative stress and inflammation. Patients will undergo these measures at baseline, six and 12 months. Discussion The results of this study will help determine the efficacy of astaxanthin on vascular structure, oxidative stress and inflammation in renal transplant patients. This may lead to a larger intervention trial assessing cardiovascular morbidity and mortality. Trial Registration

  12. Chirality and gravitational parity violation.

    Science.gov (United States)

    Bargueño, Pedro

    2015-06-01

    In this review, parity-violating gravitational potentials are presented as possible sources of both true and false chirality. In particular, whereas phenomenological long-range spin-dependent gravitational potentials contain both truly and falsely chiral terms, it is shown that there are models that extend general relativity including also coupling of fermionic degrees of freedom to gravity in the presence of torsion, which give place to short-range truly chiral interactions similar to that usually considered in molecular physics. Physical mechanisms which give place to gravitational parity violation together with the expected size of the effects and their experimental constraints are discussed. Finally, the possible role of parity-violating gravity in the origin of homochirality and a road map for future research works in quantum chemistry is presented.

  13. Synthetic Applications of Chiral Furanboronate

    Institute of Scientific and Technical Information of China (English)

    CHAN KinFai; WONG Henry N,C.

    2001-01-01

    @@ We recently uncovered that consecutive reactions of chiral furfural-boronate 1 with a lithium alkoxide and a nucleophile led to the formation of alcohols 2 with good diastereoselection in favor of S-configuration at the newly generated chiral carbon. In addition, it was also found that 2a and 2b were chromatographically separable on a silica gel column. This reaction is believed to involve a tetrahedral borate intermediate, as can be substantiated by 11BNMR spectroscopic studies. Chiral furanmethanolboronates 2a(or 2b) underwent a palladium-catalyzed Suzuki coupling to form enantiomerically pure furans 3, which can be further converted to the synthetically useful hydroxypyranones 4.1,2,3 In addition, Mukaiyama reaction of 1 also led to chromatographically separable diastereomeric aldol-products. The scope and limitation of these conversions will be discussed.

  14. Synthetic Applications of Chiral Furanboronate

    Institute of Scientific and Technical Information of China (English)

    CHAN; KinFai

    2001-01-01

    We recently uncovered that consecutive reactions of chiral furfural-boronate 1 with a lithium alkoxide and a nucleophile led to the formation of alcohols 2 with good diastereoselection in favor of S-configuration at the newly generated chiral carbon. In addition, it was also found that 2a and 2b were chromatographically separable on a silica gel column. This reaction is believed to involve a tetrahedral borate intermediate, as can be substantiated by 11BNMR spectroscopic studies. Chiral furanmethanolboronates 2a(or 2b) underwent a palladium-catalyzed Suzuki coupling to form enantiomerically pure furans 3, which can be further converted to the synthetically useful hydroxypyranones 4.1,2,3 In addition, Mukaiyama reaction of 1 also led to chromatographically separable diastereomeric aldol-products. The scope and limitation of these conversions will be discussed.  ……

  15. Chiral separation of agricultural fungicides.

    Science.gov (United States)

    Pérez-Fernández, Virginia; García, Maria Ángeles; Marina, Maria Luisa

    2011-09-23

    Fungicides are very important and diverse environmental and agricultural concern species. Their determination in commercial formulations or environmental matrices, requires highly efficient, selective and sensitive methods. A significant number of these chemicals are chiral with the activity residing usually in one of the enantiomers. The different toxicological and degradation behavior observed in many cases for fungicide enantiomers, results in the need to investigate them separately. For this purpose, separation techniques such as GC, HPLC, supercritical fluid chromatography (SFC) and CE have widely been employed although, at present, HPLC still dominates chromatographic chiral analysis of fungicides. This review covers the literature concerning the enantiomeric separation of fungicides usually employed in agriculture grouping the chiral separation methodologies developed for their analysis in environmental, biological, and food samples.

  16. 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 0.020-0.187 nM and 0.003-0.232 nM with detection limit of 0.00073 nM and 0.00016 nM, 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.

  17. A sub-chronic toxicity evaluation of a natural astaxanthin-rich carotenoid extract of Paracoccus carotinifaciens in rats

    Directory of Open Access Journals (Sweden)

    Toyohisa Katsumata

    2014-01-01

    Full Text Available Astaxanthin is believed to be beneficial to human health because it possesses strong antioxidant properties. A natural astaxanthin-rich carotenoid extract (ARE was produced by a well-controlled fermentation of a natural bacteria Paracoccus carotinifaciens, followed by the extraction and enrichment of the final product comprising mixture of carotenoids that is predominantly astaxanthin. The aim of this study was to evaluate the sub-chronic toxicity of the ARE using 6 week old Sprague-Dawley SPF rats [Crl:CD(SD]. The test article was suspended in olive oil and administered daily to the rats by oral gavage for 13 weeks at doses of 0 (olive oil, 250, 500 or 1000 mg/kg/day. Each group consisted of 10 animals of each sex. No deaths occurred and no treatment-related changes were observed in the detailed clinical observations, manipulative tests, grip strength, motor activity, body weights, food consumption, ophthalmology, urinalysis, hematology, blood chemistry, organ weight, necropsy or histopathology. Dark-red feces were observed throughout the administration period in all treated groups due to excretion of the colored test article. Based on these results, it was concluded that the no observed adverse effect level (NOAEL for ARE was at least 1000 mg/kg/day for male and female rats, respectively.

  18. Optimization and Application of Liquid Chromatography Determination of Dispersive Liquid-liquid Microextraction Purified Astaxanthin in Shrimp Waste

    Institute of Scientific and Technical Information of China (English)

    ZHU Tao; ROW Kyung-ho

    2013-01-01

    A new molecularly imprinted solid-phase extraction(MISPE) monolithic cartridge was synthesized,and MISPE-DLLME(DLLME=dispersive liquid-liquid microextraction) was developed for purification of astaxanthin in shrimp waste.The eluent(methanol) from MISPE was used as the dispersive solvent in subsequent DLLME for further purifying and enriching the analyte prior to high-performance liquid chromatography(HPLC) analysis.The mobile phase was methanol-acetonitrile-water-dichloromethane(85:5:5:5,volume ratio),flow rate was 0.7 mL/min and UV wavelength was 476 nm.Under optimal conditions,good linearity was obtained in a range of 0.2-200.0 μg/mL(r2=0.9998) with a limit of detection(LOD) of 0.08 μg/mL,and the extraction recoveries at three spiked levels ranged from 88.3%-92.5% with a relative standard deviation(RSD) less than 4.3%.Moreover,the mean contents of astaxanthin in the three batches of shrimp waste were 95.9,85.4 and 77.2 μg/g,respectively.This method combining the advantages of MISPE and DLLME results in high selectivity and low cost,which was applied to determining the astaxanthin level in shrimp waste samples.

  19. Astaxanthin and papilioerythrinone in the skin of birds: a chromatic convergence of two metabolic routes with different precursors?

    Science.gov (United States)

    García-de Blas, Esther; Mateo, Rafael; Guzmán Bernardo, Francisco Javier; Rodríguez Martín-Doimeadios, Rosa Carmen; Alonso-Alvarez, Carlos

    2014-05-01

    Carotenoids are organic pigments involved in several important physiological functions and may serve as indicators of individual quality in animals. These pigments are only obtained by animals from the diet, but they can be later transformed into other carotenoids by specific enzymatic reactions. The diet of farm-reared and probably wild red-legged partridges ( Alectoris rufa) is mainly based on cereals that contain high levels of lutein and zeaxanthin. These two carotenoids are also predominant in internal tissues and blood of red-legged partridges. However, in their integuments, astaxanthin and papilioerythrinone (the last one identified in this work) are mainly present in their free form and esterified with fatty acids. According to available literature about carotenoid metabolism in animals, we propose that astaxanthin ( λ max = 478 nm) and papilioerythrinone ( λ max = 452-478 nm) are the result of a chromatic convergence of the transformation of dietary zeaxanthin and lutein, respectively. Moreover, the results obtained in this work provide the first identification by liquid chromatography coupled to accurate mass quadrupole time-of-flight mass spectrometer system of papilioerythrinone ( m/z 581.3989 [M + H]+) in the skin (i.e., not feathers) of a vertebrate. Astaxanthin and papilioerythrinone are very close in terms of chemical structure and coloration, and the combination of these two keto-carotenoids is responsible for the red color of the ornaments in red-legged partridges.

  20. Development and Application of Astaxanthin%虾青素的开发与应用进展

    Institute of Scientific and Technical Information of China (English)

    汪多仁

    2011-01-01

    全文介绍了虾青素的性能,主要生产的技术路线与最佳的操作条件等有关进展情况。对目前工业化采用的主要虾青素生产工艺的技术特点进行了具体的分析和总结,阐述了国内外研究开发的现状与发展趋势。并探讨扩大应用与市场需求。%Advances in and prospect of Astaxanthin manufacturing technology The Progress in Astaxanthin manufacturing technology were reviewed In the paper.The features of technologies for industrial production of high purity glucose were dis cussed and reviewed.processes of Astaxanthin producing and optimum conditions and new development of magnesium borate whisker and their status quo and development trends of sends at home and abroad have been presented in the article for future application are evaluated and marked demand.

  1. Medium optimization to improve astaxanthin production of Xanthophyllomyces dendrorhous mutant W6-8 based on genetic algorithms

    Institute of Scientific and Technical Information of China (English)

    WangWenjun; YuLongjiang; HePu; ZhouPengpeng

    2004-01-01

    Genetic algorithms (GA) based on the principle of mimicing Darwinian evolution and survival of the fittest in a natural environment was used to optimize the medium for astaxanthin production by the mutant strain W6-8 of Xantho-phyllomyces dendrorhous. The 50 concentration levels of 6 medium components were optimized within 50 experiments (full experimental plan: 506 experiments). The results showed that GA could be applied in the medium optimization and better results were obtained. By employing optimized medium components (glucose 39.8 g l-1, yeast extract 4.08 g l-1,(NH4)2SO4 7.36 g l-1, MgSO4 2 g l-1, K2HPO4 2.04 g l-1 and KH2PO4 3.48 g l-1), the highest astaxanthin production was 9.855 mg l-1, approximately 31% higher than that under the initial conditions, and was approximately 15.46% higher than that by orthogonal array but only slightly higher than that by response surface methodology. In the sequent scale-up experiments, the astaxanthin yield was obtained approximately 14.753 mg l-1, employing the optimal medium. The results indicated that GA, as an euiicient method for medium optimization, was superior to other optimal means such as orthogonal array.

  2. Low-cost production of 6G-fructofuranosidase with high value-added astaxanthin by Xanthophyllomyces dendrorhous.

    Science.gov (United States)

    Ning, Yawei; Li, Qiang; Chen, Feng; Yang, Na; Jin, Zhengyu; Xu, Xueming

    2012-01-01

    The effects of medium composition and culture conditions on the production of (6)G-fructofuranosidase with value-added astaxanthin were investigated to reduce the capital cost of neo-fructooligosaccharides (neo-FOS) production by Xanthophyllomyces dendrorhous. The sucrose and corn steep liquor (CSL) were found to be the optimal carbon source and nitrogen source, respectively. CSL and initial pH were selected as the critical factors using Plackett-Burman design. Maximum (6)G-fructofuranosidase 242.57 U/mL with 5.23 mg/L value-added astaxanthin was obtained at CSL 52.5 mL/L and pH 7.89 by central composite design. Neo-FOS yield could reach 238.12 g/L under the optimized medium conditions. Cost analysis suggested 66.3% of substrate cost was reduced compared with that before optimization. These results demonstrated that the optimized medium and culture conditions could significantly enhance the production of (6)G-fructofuranosidase with value-added astaxanthin and remarkably decrease the substrate cost, which opened up possibilities to produce neo-FOS industrially.

  3. Engineering of geranylgeranyl pyrophosphate synthase levels and physiological conditions for enhanced carotenoid and astaxanthin synthesis in Xanthophyllomyces dendrorhous.

    Science.gov (United States)

    Breitenbach, Jürgen; Visser, Hans; Verdoes, Jan C; van Ooyen, Albert J J; Sandmann, Gerhard

    2011-04-01

    The basidiomycetous yeast, Xanthophyllomyces dendrorhous, is one of the very few organisms which can be used for biological production of the carotenoid astaxanthin. crtE cDNA has been cloned from this fungus for engineering of the terpenoid pathway. The function of its gene product as a geranylgeranyl pyrophosphate synthase was established. X. dendrorhous was transformed with the crtE cDNA to divert metabolite flow from the sterol pathway towards carotenoid biosynthesis. Transformants were obtained with increased levels of geranylgeranyl pyrophosphate synthase leading to higher carotenoid levels including astaxanthin. Physiological conditions for maximum carotenoid synthesis for wild type and the CrtE transformant were dim light and extra air supply of the shaking culture. These conditions and the transformation with crtE had additive effects and resulted in an 8-fold higher astaxanthin formation as compared to the initial wild type culture without illumination and extra air supply yielding 451 μg/g dry wt within 4 days of growth.

  4. Novel Chiral Auxiliaries of BIAZOLs

    Institute of Scientific and Technical Information of China (English)

    CHEN; Arh-Hwang

    2001-01-01

    Asymmetric catalysis is one of the most challenging and formidable endeavor in organic synthesis. The development of chiral auxiliaries is a key in the asymmetric catalysis. Azulenoids, a parent structure of bicyclo[5.3.0]decapentaene with 10 πelectrons, are useful as dye materials, medical treatment of inflammation and hypertension, and the development of liquid crystals. In continuing to investigate synthetic application of azulenoids, we have studied to develop novel chiral auxiliaries of BIAZOLs. The BIAZOLs were synthesized from dicyclopentadiene and characterized using spectroscopies.  ……

  5. Novel Chiral Auxiliaries of BIAZOLs

    Institute of Scientific and Technical Information of China (English)

    CHEN Arh-Hwang; YUAN Shou-Bin; CHIU Shu-Ching

    2001-01-01

    @@ Asymmetric catalysis is one of the most challenging and formidable endeavor in organic synthesis. The development of chiral auxiliaries is a key in the asymmetric catalysis. Azulenoids, a parent structure of bicyclo[5.3.0]decapentaene with 10 πelectrons, are useful as dye materials, medical treatment of inflammation and hypertension, and the development of liquid crystals. In continuing to investigate synthetic application of azulenoids, we have studied to develop novel chiral auxiliaries of BIAZOLs. The BIAZOLs were synthesized from dicyclopentadiene and characterized using spectroscopies.

  6. Asymmetric Synthesis via Chiral Aziridines

    DEFF Research Database (Denmark)

    Tanner, David Ackland; Harden, Adrian; Wyatt, Paul

    1996-01-01

    A series of chiral bis(aziridines) has been synthesised and evaluated as chelating ligands for a variety of asymmetric transformations mediated by metals [Os (dihydroxylation), Pd (allylic alkylation) Cu (cyclopropanation and aziridination, Li (1,2-addition of organolithiums to imines)]. In the b......A series of chiral bis(aziridines) has been synthesised and evaluated as chelating ligands for a variety of asymmetric transformations mediated by metals [Os (dihydroxylation), Pd (allylic alkylation) Cu (cyclopropanation and aziridination, Li (1,2-addition of organolithiums to imines...

  7. Collisions in Chiral Kinetic Theory

    CERN Document Server

    Chen, Jing-Yuan; Stephanov, Mikhail A

    2015-01-01

    Using a covariant formalism, we construct a chiral kinetic theory Lorentz invariant to order $\\mathcal O(\\hbar)$ which includes collisions. We find a new contribution to the particle number current due to the side jumps required by the conservation of angular momentum during collisions. We also find a conserved symmetric stress-energy tensor as well as the $H$-function obeying Boltzmann's $H$-theorem. We demonstrate their use by finding a general equilibrium solution and the values of the anomalous transport coefficients characterizing chiral vortical effect.

  8. Strange chiral nucleon form factors

    CERN Document Server

    Hemmert, T R; Meißner, Ulf G; Hemmert, Thomas R.; Kubis, Bastian; Meissner, Ulf-G.

    1999-01-01

    We investigate the strange electric and magnetic form factors of the nucleon in the framework of heavy baryon chiral perturbation theory to third order in the chiral expansion. All counterterms can be fixed from data. In particular, the two unknown singlet couplings can be deduced from the parity-violating electron scattering experiments performed by the SAMPLE and the HAPPEX collaborations. Within the given uncertainties, our analysis leads to a small and positive electric strangeness radius, $ = (0.05 \\pm 0.16) fm^2$. We also deduce the consequences for the upcoming MAMI A4 experiment.

  9. Effects of butanol isomers on dipalmitoylphosphatidylcholine bilayer membranes.

    Science.gov (United States)

    Reeves, Megan D; Schawel, Adam K; Wang, Weidong; Dea, Phoebe

    2007-06-01

    Differential scanning calorimetry and (31)P-NMR were used to study the effects of butanol isomers on the thermotropic phase behavior of dipalmitoylphosphatidylcholine (DPPC) bilayers. The threshold concentration for the onset of interdigitation for each isomer was determined by the disappearance of the pretransition and the onset of a large hysteresis between the heating and cooling scans of the gel-to-liquid main transition. The threshold concentration was found to correlate with increased solubility of the isomers in the aqueous phase, led by tert-butanol. However, as the solution concentration of tert-butanol increased, there was an abrupt shrinking of the hysteresis, initially with well-resolved shoulder peaks indicating mixed phases. The eventual disappearance of the shoulder peaks was correlated with a breakdown of the multilamellar structure identified using (31)P-NMR.

  10. Dynamic chirality, chirality transfer and aggregation behaviour of dithienylethene switches

    NARCIS (Netherlands)

    de Jong, Jaap J. D.; van Rijn, Patrick; Tiemersma-Wegeman, Theodora D.; Lucas, Linda N.; Browne, Wesley R.; Kellogg, Richard M.; Uchida, Kingo; Van Esch, Jan H.; Feringa, Ben L.

    2008-01-01

    The synthesis and characterisation of a series of chiral and achiral low molecular weight organogelators (LMWGs) based on bis-amide substituted dithienylethene photochromic switches is reported. The LMWGs gelate a range of solvents depending on the specific functionalisation of the hydrogen bonding

  11. K stability and stability of chiral ring

    CERN Document Server

    Collins, Tristan C; Yau, Shing-Tung

    2016-01-01

    We define a notion of stability for chiral ring of four dimensional N=1 theory by introducing test chiral rings and generalized a maximization. We conjecture that a chiral ring is the chiral ring of a superconformal field theory if and only if it is stable. We then study N=1 field theory derived from D3 branes probing a three-fold singularity X, and show that the K stability which implies the existence of Ricci-flat conic metric on X is equivalent to the stability of chiral ring of the corresponding field theory.

  12. Dietary values of astaxanthin and canthaxanthin in Penaeus monodon in the presence and absence of cholesterol supplementation: effect on growth, nutrient digestibility and tissue carotenoid composition.

    Science.gov (United States)

    Niu, Jin; Li, Chun-Hou; Liu, Yong-Jian; Tian, Li-Xia; Chen, Xu; Huang, Zhong; Lin, Hei-Zhao

    2012-07-14

    Penaeus monodon (mean initial wet weight 1·19 (SE 0·01) g) were fed seven diets in triplicate: a control diet (D1) without carotenoids; three diets formulated to supply 0·1 % astaxanthin alone (D2), 0·2 % astaxanthin alone (D3), and a combination of 0·1 % astaxanthin and 1 % cholesterol (D4); three diets with 0·07 % canthaxanthin alone (D5), 0·13 % canthaxanthin alone (D6), and a combination of 0·07 % canthaxanthin and 1 % cholesterol (D7). Weight gain (WG, %), specific growth rate (SGR, %/d) and survival were chosen as parameters of shrimp growth performance. Total antioxidant status (TAS), superoxide dismutase (SOD), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were chosen as indices of shrimp plasma antioxidant capacity. Meanwhile, digestibility, retention efficiency and tissue carotenoids were also investigated to determine the additive effect of cholesterol on the efficiency of astaxanthin and canthaxanthin. After 74 d rearing, WG and SGR of shrimp fed D2-D4 and D7 were higher than those of shrimp fed D1 (P astaxanthin in D2-D4 were higher than those of canthaxanthin in D5-D7 (P astaxanthin were quite high (>98 %) in D2-D4 and no differences were found among them (P>0·05), the carotenoid retention efficiencies in the whole body, muscle and shell (D2-D3 treatments) were considerably low; however, cholesterol supplementation significantly improved the carotenoid retention efficiencies in the whole body, muscle and shell (D4 treatment). Accordingly, the addition of cholesterol also significantly enhanced the carotenoid contents of tissues. Shrimp fed supplemented carotenoid diets (D2-D7) had higher TAS and lower SOD, ALT and AST than shrimp fed D1 (P astaxanthin or canthaxanthin was higher than that of shrimp fed D1 during the stress test (P astaxanthin was better than canthaxanthin as the dietary carotenoid source in the commercial diet of P. monodon, and the supplement of cholesterol could positively enhance the efficiency of

  13. Supplementating with dietary astaxanthin combined with collagen hydrolysate improves facial elasticity and decreases matrix metalloproteinase-1 and -12 expression: a comparative study with placebo.

    Science.gov (United States)

    Yoon, Hyun-Sun; Cho, Hyun Hee; Cho, Soyun; Lee, Se-Rah; Shin, Mi-Hee; Chung, Jin Ho

    2014-07-01

    Photoaging accounts for most age-related changes in skin appearance. It has been suggested that both astaxanthin, a potent antioxidant, and collagen hydrolysate can be used as antiaging modalities in photoaged skin. However, there is no clinical study using astaxanthin combined with collagen hydrolysate. We investigated the effects of using a combination of dietary astaxanthin and collagen hydrolysate supplementation on moderately photoaged skin in humans. A total of 44 healthy subjects were recruited and treated with astaxanthin (2 mg/day) combined with collagen hydrolysate (3 g/day) or placebos, which were identical in appearance and taste to the active supplementation for 12 weeks. The elasticity and hydration properties of facial skin were evaluated using noninvasive objective devices. In addition, we also evaluated the expression of procollagen type I, fibrillin-1, matrix metalloproteinase-1 (MMP-1) and -12, and ultraviolet (UV)-induced DNA damage in artificially UV-irradiated buttock skin before and after treatment. The supplement group showed significant improvements in skin elasticity and transepidermal water loss in photoaged facial skin after 12 weeks compared with the placebo group. In the supplement group, expression of procollagen type I mRNA increased and expression of MMP-1 and -12 mRNA decreased compared with those in the placebo group. In contrast, there was no significant difference in UV-induced DNA damage between groups. These results demonstrate that dietary astaxanthin combined with collagen hydrolysate can improve elasticity and barrier integrity in photoaged human facial skin, and such treatment is well tolerated.

  14. Effect of red cyst cell inoculation and iron(II) supplementation on autotrophic astaxanthin production by Haematococcus pluvialis under outdoor summer conditions.

    Science.gov (United States)

    Hong, Min-Eui; Choi, Yoon Young; Sim, Sang Jun

    2016-01-20

    The negative effect of heat stress on the autotrophic astaxanthin production by Haematococcus pluvialis has been observed during outdoor culture in summer. Under the summer conditions, the proliferation of vegetative cells was highly halted in the green stage and the inducibility in the biosynthesis of astaxanthin was partly hindered in the red stage. Herein, under outdoor summer conditions in which variations of the diurnal temperature occur, heat-stress-driven inefficient vegetative growth of H. pluvialis was highly improved by inoculating the red cyst cells; thereby, maintaining relatively moderate intracellular carotenoid levels in the green stage. Subsequently, a remarkably enhanced astaxanthin titer was successfully obtained by supplementing 50 μM iron(II) to induce the heat stress-driven Haber-Weiss reaction in the red stage. As a result, the productivity of astaxanthin in the cells cultured under summer temperature conditions (23.4-33.5 °C) using the two methods of red cell (cyst) inoculation and the iron(Fe(2+)) supplementation was increased by 147% up to 5.53 mg/L day compared with that of the cells cultured under spring temperature conditions (17.5-27.3 °C). Our technical solutions will definitely improve the annual natural astaxanthin productivity in H. pluvialis in locations confronted by hot summer weather, particularly in large-scale closed photobioreactor systems.

  15. Thermal chiral vortical and magnetic waves: new excitation modes in chiral fluids

    CERN Document Server

    Kalaydzhyan, Tigran

    2016-01-01

    In certain circumstances, chiral (parity-violating) medium can be described hydrodynamically as a chiral fluid with microscopic quantum anomalies. Possible examples of such systems include strongly coupled quark-gluon plasma, liquid helium 3He-A, neutron stars and the Early Universe. We study first-order hydrodynamics of a chiral fluid on a vortex background and in a external magnetic field. We show that there are two previously undiscovered modes describing heat waves propagating along the vortex and magnetic field. We call them the Thermal Chiral Vortical Wave and Thermal Chiral Magnetic Wave. We also identify known gapless excitations of density, the chiral vortical and chiral magnetic waves. We demonstrate that the velocity of the chiral vortical wave is zero, when the full hydrodynamic framework is applied, and hence the excitation reduces to a charge diffusion mode or is completely absent. We also correct the dispersion relation for the chiral magnetic wave.

  16. Evidence for the effect of sorption enantioselectivity on the availability of chiral pesticide enantiomers in soil.

    Science.gov (United States)

    Gámiz, Beatriz; Facenda, Gracia; Celis, Rafael

    2016-06-01

    Although enantioselective sorption to soil particles has been proposed as a mechanism that can potentially influence the availability of individual chiral pesticide enantiomers in the environment, environmental fate studies generally overlook this possibility and assume that only biotic processes can be enantioselective, whereas abiotic processes, such as sorption, are non-enantioselective. In this work, we present direct evidence for the effect of the enantioselective sorption of a chiral pesticide in a natural soil on the availability of the single pesticide enantiomers for transport. Batch sorption experiments, with direct determination of the sorbed amounts, combined with column leaching tests confirmed previous observations that from non-racemic aqueous solutions the sorption of the chiral fungicide metalaxyl on the soil appeared to be enantioselective, and further demonstrated that the enantiomer that was sorbed to a greater extent (R-metalaxyl, Kd = 1.73 L/kg) exhibited retarded leaching compared to its optical isomer (S-metalaxyl, Kd = 1.15 L/kg). Interconversion and degradation of the pesticide enantiomers, which are potential experimental artifacts that can lead to erroneous estimates of sorption and its enantioselectivity, were discarded as possible causes of the observed enantioselective behavior. The results presented here may have very important implications for a correct assessment of the environmental fate of chiral pesticides that are incorporated into the environment as non-racemic mixtures, and also of aged chiral pesticide residues that have been transformed from racemic to non-racemic by biologically-mediated processes.

  17. Iterative tandem catalysis of secondary diols and diesters to chiral polyesters.

    Science.gov (United States)

    van As, Bart A C; van Buijtenen, Jeroen; Mes, Tristan; Palmans, Anja R A; Meijer, E W

    2007-01-01

    The well-known dynamic kinetic resolution of secondary alcohols and esters was extended to secondary diols and diesters to afford chiral polyesters. This process is an example of iterative tandem catalysis (ITC), a polymerization method where the concurrent action of two fundamentally different catalysts is required to achieve chain growth. In order to procure chiral polyesters of high enantiomeric excess value (ee) and good molecular weight, the catalysts employed need to be complementary and compatible during the polymerization reaction. We here show that Shvo's catalyst and Novozym 435 fulfil these requirements. The optimal polymerization conditions of 1,1'-(1,3-phenylene) diethanol (1,3-diol) and diisopropyl adipate required 2 mol% Shvo's catalyst and 12 mg Novozym 435 per mmol alcohol group in the presence of 0.5 M 2,4-dimethyl-3-pentanol as the hydrogen donor. With these conditions, chiral polyesters were obtained with peak molecular weights up to 15 kDa, an ee value up to 99% and with 1-3 % ketone end groups. Also with the structural isomer, 1,4-diol, a chiral polyester was obtained, albeit with lower molecular weight (8.3 kDa) and slightly lower ee (94%). Aliphatic secondary diols also resulted in enantio-enriched polymers but at most an ee of 46 % was obtained with molecular weights in the range of 3.3-3.7 kDa. This low ee originates from the intrinsic low enantioselectivity of Novozym 435 for this type of secondary aliphatic diols. The results presented here show that ITC can be applied to procure chiral polyesters with good molecular weight and high ee from optically inactive AA-BB type monomers.

  18. Chiral magnetic plasmons in anomalous relativistic matter

    CERN Document Server

    Gorbar, E V; Shovkovy, I A; Sukhachov, P O

    2016-01-01

    The chiral plasmon modes of relativistic matter in background magnetic and strain-induced pseudomagnetic fields are studied in detail using the consistent chiral kinetic theory. The results reveal a number of anomalous features of these chiral magnetic and pseudomagnetic plasmons that could be used to identify them in experiment. In a system with nonzero electric (chiral) chemical potential, the background magnetic (pseudomagnetic) fields not only modify the values of the plasmon frequencies in the long wavelength limit, but also affect the qualitative dependence on the wave-vector. Similar modifications can be also induced by the chiral shift parameter in Weyl materials. Interestingly, even in the absence of the chiral shift and external fields, the chiral chemical potential alone leads to a splitting of plasmon energies at linear order in the wave vector.

  19. Preparation and application of methylcalix[4]resorcinarene-bonded silica particles as chiral stationary phase in high-performance liquid chromatography.

    Science.gov (United States)

    Tan, Huey Min; Soh, Shu Fang; Zhao, Jia; Yong, E L; Gong, Yinhan

    2011-01-01

    Two new types of methylcalix[4]resorcinarene-bonded stationary phases, (3-(C-methylcalix[4]resorcinarene)-2-hydroxypropoxy)-propylsilyl-appended silica particles (MCR-HPS) and bromoacetate-substituted MCR-HPS particles (BAMCR-HPS), have been synthesized and used as chiral stationary phases for high-performance liquid chromatography (HPLC) for the first time. The synthetic stationary phases are characterized by means of elemental analysis and Fourier-transform infrared spectroscopy. The chromatographic behavior of MCR-HPS and BAMCR-HPS was studied with several disubstituted benzenes and some chiral drug compounds under both normal phase and reversed-phase conditions. The results show that MCR-HPS has excellent selectivity for the separation of aromatic positional isomers and BAMCR-HPS exhibits excellent performance for separation of enantiomers of chiral compounds.

  20. Algebraic study of chiral anomalies

    Indian Academy of Sciences (India)

    Juan Mañes; Raymond Stora; Bruno Zumino

    2012-06-01

    The algebraic structure of chiral anomalies is made globally valid on non-trivial bundles by the introduction of a fixed background connection. Some of the techniques used in the study of the anomaly are improved or generalized, including a systematic way of generating towers of ‘descent equations’.