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Sample records for s-2-3-aminopropylamino ethylphosphorothioic acid

  1. Protective effect of S-2-(3-aminopropylamino)ethylphosphorothioic acid (WR-2721) on irradiation-induced inhibition of intestinal transport function

    International Nuclear Information System (INIS)

    Chen, T.S.; Ando, M.

    1983-01-01

    The purpose of this study was to investigate the protective effect of S-2-(3-aminopropylamino)ethylphosphorothioic acid (WR-2721) on whole-body irradiation-induced inhibition of intestinal transport function. The jejunal transport of fluid and sugars was studied in male Swiss-Webster mice before and 3 days after whole-body irradiation (1000 rads). The rates of glucose and water transport were decreased by 86 and 70%, respectively, in irradiated animals. However, the rate of transport of 3-O-methyl-D-glucose (3MG) was not affected. In mice receiving WR-2721 (500 mg/kg, ip) 15 to 30 min prior to whole-body irradiation, net water flux was unaffected and the rate of D-glucose transport was decreased only 8%. WR-2721 administered alone (500 mg/kg, ip) had no effect on either D-glucose transport or net water flux across the jejunal mucosa. The results suggest that WR-2721 protects against irradiation-induced inhibition of some intestinal transport functions

  2. Bone and parathyroid inhibitory effects of S-2(3-aminopropylamino)ethylphosphorothioic acid. Studies in experimental animals and cultured bone cells

    International Nuclear Information System (INIS)

    Attie, M.F.; Fallon, M.D.; Spar, B.; Wolf, J.S.; Slatopolsky, E.; Goldfarb, S.

    1985-01-01

    S-2-(3-aminopropylamino)ethylphosphorothioic acid (WR 2721) is a radio- and chemoprotective agent which produces hypocalcemia in humans. Intravenous injection of 30 mg/kg WR 2721 in rats and 15 mg/kg in dogs lowers serum calcium by 19 and 25%, respectively. Hypocalcemia in dogs is associated with a fall in serum immunoreactive parathyroid hormone (PTH), which suggests that the mechanism of its hypocalcemic effect is acute hypoparathyroidism. Despite this effect on PTH, in eight chronically parathyroidectomized rats on a low phosphate diet, WR 2721 reduced serum calcium from 9.4 to 7.7 mg/dl at 3 h. Furthermore, in dogs rendered hypercalcemic by continuous infusion of PTH, WR 2721 reduced serum calcium from 11.0 to 10.6 mg/dl. To determine whether WR 2721 causes hypocalcemia by enhancing the exit of calcium from the circulation or inhibiting its entry, the drug was infused 3 h after administration of 45 Ca to rats. WR 2721 did not significantly increase the rate of disappearance of 45 Ca from the circulation even though serum calcium fell by 19%. In incubations with fetal rat long bone labeled in utero with 45 Ca, 10(-3) M WR 2721 inhibited PTH-stimulated, but not base-line release of 45 Ca. Bone resorption by primary culture of chick osteoclasts was inhibited by WR 2721 at concentrations as low as 10(-4) M in the absence of hormonal stimulation. These studies suggest that WR 2721 lowers serum calcium predominantly by blocking calcium release from bone. This acute hypocalcemic effect is at least in part independent of its effect on the parathyroid glands, and is most likely a direct effect of the agent on bone resorption

  3. Protection by S-2-(3-aminopropylamino)ethylphosphorothioic acid against radiation- and cyclophosphamide-induced attenuation in antitumor resistance

    International Nuclear Information System (INIS)

    Milas, L.; McBride, W.H.; Hunter, N.; Ito, H.

    1984-01-01

    Studies were performed to investigate whether S-2-(3-amino-propylamino)ethylphosphorothioic acid (WR-2721) can protect antitumor immune rejection responses against the damaging effects of whole-body irradiation (WBI) and cyclophosphamide (CY). The ability of WR-2721 to protect against WBI -induced decreased radioresponse of solitary tumors was also investigated. All experiments were performed with an immunogenic fibrosarcoma syngeneic to C3Hf/ Kam mice. WR-2721 was given i.p. at a dose of 400 mg/kg 30 min before WBI with gamma-rays or CY injection. WBI with 650 rads reduced the number of tumor cells needed for tumor take in 50% of animals from 5.1 X 10(4) cells in normal mice to 2.0 X 10(2). WR-2721 given before WBI almost entirely abolished the effect of WBI : the number of tumor cells needed for tumor take in 50% of animals was 1.4 X 10(4). Treatment of mice with WBI or CY increased the number of tumor nodules in the lung generated by fibrosarcoma cells injected i.v. 5 days later, in a linear dose response. WR-2721 greatly reduced this metastasis enhancement effect of WBI and CY with protection factors of 2.5 for WBI and 1.8 for CY. Fibrosarcomas of 8 mm in diameter exhibited a decreased radiocurability when growing in WBI mice: the dose of irradiation yielding local tumor control in 50% of animals in these mice was 5950 compared to a dose of irradiation yielding local tumor control in 50% of animals of 4160 rads in normal mice. WR-2721 given before WBI inhibited this effect of WBI : the dose of irradiation yielding local tumor control in 50% of animals was 5210 rads. The proportion of macrophages in tumors growing in WBI mice was significantly reduced, but not when WR-2721 was first given. WR-2721 greatly reduced the damaging effects of WBI and CY on natural killer cell activity

  4. Depletion of glutathione by the radioprotective agent S-2-(3-aminopropylamino)ethyl phosphorothioic acid (WR2721)

    International Nuclear Information System (INIS)

    Schor, N.F.

    1989-01-01

    S-2-(3-Aminopropylamino)ethyl phosphorothioic acid (WR2721) is a free radical scavenger currently in limited clinical use as an adjunct in cancer radio- and chemotherapy. We have previously determined the pharmacokinetics and protein binding characteristics of WR2721 in rabbits and in humans. We have also shown that WR2721 is an effective mucolytic agent in patients with cystic fibrosis. In vivo, WR2721 is converted to its free thiol analogue, N-2-mercaptoethyl-1,3-diaminopropane (MDP), and, as such, reacts with disulfide bonds in the mucin molecule, altering its rheology. In the course of experiments designed to examine the spectrum of its activity as a free radical scavenger, we have observed that WR2721 exacerbates the toxicity of those free radical-generating agents, such as acetaminophen and 6-hydroxydopamine, which depend upon glutathione for their detoxication. For this reason, we examined the glutathione content of the livers of mice treated with WR2721. (author)

  5. Improved HPLC assay for S-2-(3-aminopropylamino)ethyl phosphorothioate (WR-2721) in plasma

    International Nuclear Information System (INIS)

    Swynnerton, N.F.; McGovern, E.P.; Nino, J.A.; Mangold, D.J.

    1984-01-01

    An HPLC assay is presented for the detection and quantitation of the radioprotective drug S-2-(3-aminopropylamino)ethyl phosphorothioate (WR-2721, ethiofos) present in plasma. Improved selectivity and a 40-fold increase in sensitivity have been demonstrated over the method previously reported by this laboratory. Using precolumn derivatization with fluorescamine and S-3-(4-aminobutylamino)propyl phosphorothioate (WR-80855, a homolog of WR-2721) as the internal standard, drug levels of 0.05 to 1000 μg/mL were determined with excellent precision. Detector response was linear over the entire range. The assay uses 150 μL of plasma and requires a total chromatography time of about 50 minutes. The method was found suitable for pharmacokinetic studies in a preliminary experiment with a beagle dog in which no interferences due to plasma constituents or drug metabolites were observed

  6. HPLC assay for 2-(3-aminopropylamino)ethanethiol (WR-1065) in plasma

    International Nuclear Information System (INIS)

    McGovern, E.P.; Swynnerton, N.F.; Steele, P.D.; Mangold, D.J.

    1984-01-01

    A high pressure liquid chromatography (HPLC) plasma assay for WR-1065 is described which is both precise and accurate throughout the concentration range from 1 to 500 μg/mL of plasma. The analyte is separated by HPLC and detected with a thiol specific electrochemical transducer cell. The detector response is linear over the ranges 1 to 10 μg/mL, 10 to 100 μg/mL, and 100 to 500 μg/mL. The absolute retention times for WR-1065 and WT-1729 are 9 and 12 minutes, respectively. The assay uses 100 μL of plasma and requires a total chromatography cycle time of 40 minutes. The method has been found suitable for the determination of WR-1065 in plasma from a beagle dog after i.v. administration of S-2-(3-aminopropylamino)ethyl phosphorothioate (WR-2721)

  7. Phase I clinical studies with WR-2721

    International Nuclear Information System (INIS)

    Kligerman, M.M.; Shaw, M.T.; Slavik, M.; Yuhas, J.M.

    1980-01-01

    Toxicity studies of S-2-(3 aminopropylamino)-ethylphosphorothioic acid (WR-2721) access patients in remission following radiation therapy. The dose has been escalated from 25 to 250 mg/m2 without significant symptoms. Inconsistent variation in the systolic blood pressure in some patients has been observed over an 8-10-point range without producing any symptoms. Combining WR-2721 with conventional radiotherapy is contemplated by intravenous injection the drug 20 to 30 minutes before irradiation. This will start as weekly injections, and the number of weekly injections will be increased progessively. Animal studies suggest that the level already safely reached could give significant protection to the normal tissues without protecting tumor

  8. Radioprotection of salivary glands by S-2-(3-aminopropylamino)-ethylphosphorothioic (amifostine) obtained in a rabbit animal model

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    Bohuslavizki, Karl H; Klutmann, Susanne; Jenicke, Lars; Brenner, Winfried; Feyerabend, Bernd; Henze, Eberhard; Clausen, Malte

    1999-08-01

    Background: Impairment of salivary gland function following high-dose radioiodine treatment (HDRIT) is a well-recognized side effect of the treatment. Because differentiated thyroid cancer has an excellent prognosis, reduction of long-term side-effects is mandatory. Therefore, the aim of this study was to investigate the radioprotective effect of amifostine in a rabbit animal model. Methods: Salivary gland scintigraphy was performed in a total of 16 New Zealand White rabbits. Uptake of {sup 99m}Tc-pertechnetate was calculated in percentage of injected activity as a quantitative measure of both salivary gland and thyroid function. Reproducibility of salivary gland scintigraphy was evaluated in one rabbit without any intervention. Fifteen rabbits were studied prior to and up to 6 months after high-dose radioiodine treatment applying 2 GBq {sup 131}I. Ten animals received 200 mg/kg amifostine prior to high-dose radioiodine therapy, and 5 served as controls. Salivary glands were examined histopathologically. Results: Variation coefficient of parenchymal function was less than 3.8% in salivary glands. Prior to HDRIT, thyroid uptake was 0.417 {+-} 0.373% and 0.421 {+-} 0.241% in control and amifostine-treated rabbits, respectively. Four weeks after HDRIT, complete ablation of the thyroid was achieved in both groups. Prior to HDRIT, uptake of {sup 99m}Tc-pertechnetate in salivary glands of five control rabbits was not significantly different from ten amifostine-treated rabbits. In control rabbits 6 months after HDRIT, parenchymal function was reduced significantly (p < 0.0001) by 75.3 {+-} 5.3% and 53.6 {+-} 17.4% in parotid and submandibular glands, respectively. In contrast, in amifostine-treated rabbits, parenchymal function was reduced by 10.6 {+-} 3.4% and 6.5 {+-} 4.3% (p > 0.05) in parotid and submandibular glands, respectively. Histopathologically, marked lipomatosis was observed in control animals but was negligible in amifostine-treated animals. Conclusion

  9. Opposite effects of WR-2721 and WR-1065 on radiation-induced hypothermia: possible correlation with oxygen uptake

    International Nuclear Information System (INIS)

    Kandasamy, S.B.; Kumar, K.S.; Hunt, W.A.; Weiss, J.F.

    1988-01-01

    Ionizing radiation induces hypothermia in guinea pigs. While systemic injection of the radioprotectant S-2-(3-aminopropylamino)ethylphosphorothioic acid (WR-2721) did not block hyperthermia induced by exposure to 10 Gy of gamma radiation, central administration did attenuate it. The dephosphorylated metabolite of WR-2721, N-(2-mercaptoethyl)-1,3-diaminopropane (WR-1065), accentuated radiation-induced hypothermia by both routes of administration. In brain homogenates, oxygen uptake was inhibited by WR-2721 but elevated by WR-1065. These results suggest that the antagonism of radiation-induced hypothermia found only after central administration of WR-2721 is due to its direct actions and not to its dephosphorylated metabolite and that this effect may be correlated with the inhibition by WR-2721 of oxygen uptake

  10. Radioprotection of salivary glands by S-2-(3-aminopropylamino)-ethylphosphorothioic (amifostine) obtained in a rabbit animal model

    International Nuclear Information System (INIS)

    Bohuslavizki, Karl H.; Klutmann, Susanne; Jenicke, Lars; Brenner, Winfried; Feyerabend, Bernd; Henze, Eberhard; Clausen, Malte

    1999-01-01

    Background: Impairment of salivary gland function following high-dose radioiodine treatment (HDRIT) is a well-recognized side effect of the treatment. Because differentiated thyroid cancer has an excellent prognosis, reduction of long-term side-effects is mandatory. Therefore, the aim of this study was to investigate the radioprotective effect of amifostine in a rabbit animal model. Methods: Salivary gland scintigraphy was performed in a total of 16 New Zealand White rabbits. Uptake of 99m Tc-pertechnetate was calculated in percentage of injected activity as a quantitative measure of both salivary gland and thyroid function. Reproducibility of salivary gland scintigraphy was evaluated in one rabbit without any intervention. Fifteen rabbits were studied prior to and up to 6 months after high-dose radioiodine treatment applying 2 GBq 131 I. Ten animals received 200 mg/kg amifostine prior to high-dose radioiodine therapy, and 5 served as controls. Salivary glands were examined histopathologically. Results: Variation coefficient of parenchymal function was less than 3.8% in salivary glands. Prior to HDRIT, thyroid uptake was 0.417 ± 0.373% and 0.421 ± 0.241% in control and amifostine-treated rabbits, respectively. Four weeks after HDRIT, complete ablation of the thyroid was achieved in both groups. Prior to HDRIT, uptake of 99m Tc-pertechnetate in salivary glands of five control rabbits was not significantly different from ten amifostine-treated rabbits. In control rabbits 6 months after HDRIT, parenchymal function was reduced significantly (p 0.05) in parotid and submandibular glands, respectively. Histopathologically, marked lipomatosis was observed in control animals but was negligible in amifostine-treated animals. Conclusion: Parenchymal damage in salivary glands induced by high-dose radioiodine treatment can be significantly reduced by amifostine in this rabbit animal model. This corresponds to data obtained in patients with differentiated thyroid cancer

  11. Chemoprevention by WR-2721

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    Grdina, D.J. [Argonne National Lab., IL (United States)]|[Chicago Univ., IL (United States). Dept. of Radiation and Cellular Oncology; Carnes, B.A. [Argonne National Lab., IL (United States)

    1993-05-01

    WR-2721 [S-2-(3-aminopropylamino)ethylphosphorothioic acid] is an effective chemopreventive agent. C57BL {times} BALB/c F{sub 1} female mice, were exposed to a single whole-body dose of 206 cGy from a {sup 60}Co photon source. Those groups treated with VATR-2721 (400 mg/kg) were administered the agent i.p. 30 min prior to irradiation. Over 90% of deaths were determined to be due to tumor involvement. WR-2721 afforded significant protection against life shortening due to radiation-induced tumors of connective tissue and epithelial tissue origins. Subsequent survival time in WR-2721-treated and irradiated animals as compared to matched irradiated-only controls was extended up to 59 days. A single exposure of animals to VVR-2721 did not affect the cumulative survival curves for unirradiated mice. WR-2721 possesses chemopreventive properties which can be clinically exploited to reduce the risk to therapy-induced secondary cancers in patients who otherwise would have an excellent prognosis for cure and long-term survival.

  12. Chemoprevention by WR-2721

    Energy Technology Data Exchange (ETDEWEB)

    Grdina, D.J. (Argonne National Lab., IL (United States) Chicago Univ., IL (United States). Dept. of Radiation and Cellular Oncology); Carnes, B.A. (Argonne National Lab., IL (United States))

    1993-01-01

    WR-2721 [S-2-(3-aminopropylamino)ethylphosphorothioic acid] is an effective chemopreventive agent. C57BL [times] BALB/c F[sub 1] female mice, were exposed to a single whole-body dose of 206 cGy from a [sup 60]Co photon source. Those groups treated with VATR-2721 (400 mg/kg) were administered the agent i.p. 30 min prior to irradiation. Over 90% of deaths were determined to be due to tumor involvement. WR-2721 afforded significant protection against life shortening due to radiation-induced tumors of connective tissue and epithelial tissue origins. Subsequent survival time in WR-2721-treated and irradiated animals as compared to matched irradiated-only controls was extended up to 59 days. A single exposure of animals to VVR-2721 did not affect the cumulative survival curves for unirradiated mice. WR-2721 possesses chemopreventive properties which can be clinically exploited to reduce the risk to therapy-induced secondary cancers in patients who otherwise would have an excellent prognosis for cure and long-term survival.

  13. Protection against radiation-induced mutations at the hprt locus by spermine and N,N double-prime-(dithiodi-2,1-ethanediyl)bis-1,3-propanediamine (WR-33278). WR-33278 and spermine protect against mutation induction

    International Nuclear Information System (INIS)

    Grdina, D.J.; Shigematsu, N.; Schwartz, J.L.

    1994-01-01

    The polyamine spermine and the disulfide N,N double-prime-(dithiodi-2,1-ethanediyl)bis-1,3-propanediamine (WR-33278) are structurally similar agents capable of binding to DNA. WR-33278 is the disulfide moiety of the clinically studied radioprotective agent S-2-(3-aminopropylamino)ethylphosphorothioic acid (WR-2721). Because of their reported structural and functional similarities, it was of interest to characterize and compare their radioprotective properties using the endpoints of cell survival and mutation induction at the hypoxanthine-guanine phosphoribosyl transferase (hprt) locus in Chinese hamster AA8 cells. In order to facilitate both the uptake of WR-33278 into cells and the direct comparison between the protective properties of WR-33278 and spermine, these agents (at concentrations of 0.01 mM and 0.001 mM) were electroporated into cells. The exposure of cells to both electroporation and irradiation gave rise to enhanced cell killing and mutation induction, with the sequence of irradiation followed 3 h later by electroporation being the more toxic protocol. Enhanced cell survival was observed following electroporation of 0.01 mM of spermine and WR-33278 30 min prior to irradiation; protection factors (PF) of 1.3 and 1.8, respectively. Neither agent was protective at a concentration of 0.001 mM. Protection against radiation-induced hprt mutations was observed for both spermine and WR-33278 under all experimental conditions tested. These data suggest that the properties of radioprotection and chemoprevention exhibited by the phosphorothioate (WR-2721) and associated aminothiol (WR-1065) and disulfide (WR-33278) metabolites may be mediated via endogenous spermine-like polyamine processes. Such a mechanism would have important implications with respect to the design and development of new generation drugs for use in radioprotection and chemoprevention

  14. Chemoprotection against fractionated radiation exposures with WR-2721: skin injury

    International Nuclear Information System (INIS)

    Echols, F.S.; Yuhas, J.M.

    1976-01-01

    These studies extend the analysis of the potential application of WR-2721 [S-2-(3-aminopropylamino)ethylphosphorothioic acid] to radiation therapy by determining the ability of the drug to protect mice against hair loss induced by multiple exposures to radiation. In the two mouse strains tested, RFM and BALB/c, the relatively low drug dose used (200 mg/kg) protected the mice against hair loss from single exposures by factors of 1.67 and 1.73. The dose necessary to produce a given level of hair loss (ED 50 ) increases with increasing number of fractions. The ED 50 increases as N/sup 0.52/ and N/sup 0.59/ in the two strains of mice when they are not drug-treated, but as N/sup 0.39/ and N/sup 0.50/ in mice that are drug-treated. Thus, the protective effectiveness of WR-2721 decreases with increasing numbers of fractions, but the drug is still able to give a dose-modifying factor of about 1.25 when the total exposure is given as a series of 9 or 10 fractions. WR-2721 appears to offer the possibility of improving the efficiency of radiotherapy under clinical conditions

  15. Dose and time relationships of the radioprotector WR-2721 on locomotor activity in mice

    International Nuclear Information System (INIS)

    Landauer, M.R.; Davis, H.D.; Dominitz, J.A.; Weiss, J.F.

    1987-01-01

    The effects of the radioprotector S-2-(3-aminopropylamino)ethylphosphorothioic acid (WR-2721) on locomotor activity were evaluated in CD2F1 male mice. Separate groups of animals (N = 10/group) received an IP injection of vehicle, 25, 50, 100, 200, or 400 mg/kg of WR-2721 immediately before testing. Horizontal and vertical activity were measured using a Digiscan automated animal activity monitor. The latency to onset and duration of action of each dose of the radioprotector were recorded. For both behavioral measures, a significant reduction was observed in activity at doses of 200 and 400 mg/kg. A dose of 200 mg/kg had a 12- to 14-min latency to onset and significantly reduced behavioral activity for 3 hr. Mice injected with 400 mg/kg exhibited locomotor deficits within 8-10 min and were affected for up to 9 hr. The ED50 for horizontal and vertical activities at 1 hr postinjection were determined to be 271 and 105 mg/kg, respectively. The results demonstrate that significant reductions in locomotor activity are exhibited at doses of 200 mg/kg or more and that vertical activity was more sensitive to the disruptive effects of WR-2721 than was horizontal activity

  16. Inhibition of topoisomerase IIα activity in CHO K1 cells by 2-[(aminopropyl)amino]ethanethiol (WR-1065)

    International Nuclear Information System (INIS)

    Grdina, D.J.

    1993-06-01

    The aminothiol 2-[(aminopropyl)amino]ethanethiol (WR-1065) is the active thiol of the clinically studied radioprotective agent S-2-(3-aminopropylamino)ethylphosphorothioic acid (WR-2721). WR-1065 is an effective radiation protector and antimutagenic agent when it is administered 30 min prior to radiation exposure to Chinese hamster ovary Kl cells at a concentration of 4 mM. Under these exposure conditions, topoisomerase (topo) I and II activities and associated protein contents were measured in the K1 cell line using the DNA relaxation assay, the P4 unknotting assay, and immunoblotting, respectively. WR-1065 was ineffective in modifying topo I activity, but it did reduce topo IIa activity by an average of 50 percent. The magnitude of topo IIa protein content, however, was not affected by these exposure conditions. Cell cycle effects were monitored by the method of flow cytometry. Exposure of cells to 4 mM WR-1065 for a period of up to 6 h resulted in a buildup of cells in the G2 compartment. However, in contrast to topo II inhibitors used in chemotherapy, WR-1065 is an effective radioprotector agent capable of protecting against both radiation-induced cell lethality and mutagenesis. One of several mechanisms of radiation protection attributed to aminothiol compounds such as WR-1065 has been their ability to affect endogenous enzymatic reactions involved in DNA synthesis, repair, and cell cycle progression. These results are consistent with such a proposed mechanism and demonstrate in particular a modifying effect by 2-[(aminopropyl)amino]ethanethiol on type II topoisomerase, which is involved in DNA synthesis

  17. Inhibition of topoisomerase II{alpha} activity in CHO K1 cells by 2-[(aminopropyl)amino]ethanethiol (WR-1065)

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    Grdina, D.J. [Argonne National Lab., IL (United States)]|[Chicago Univ., IL (United States). Dept. of Radiation and Cellular Oncology; Constantinou, A. [Illinois Univ., Chicago, IL (United States). Specialized Cancer Center; Shigematsu, N.; Murley, J.S. [Argonne National Lab., IL (United States)

    1993-06-01

    The aminothiol 2-[(aminopropyl)amino]ethanethiol (WR-1065) is the active thiol of the clinically studied radioprotective agent S-2-(3-aminopropylamino)ethylphosphorothioic acid (WR-2721). WR-1065 is an effective radiation protector and antimutagenic agent when it is administered 30 min prior to radiation exposure to Chinese hamster ovary Kl cells at a concentration of 4 mM. Under these exposure conditions, topoisomerase (topo) I and II activities and associated protein contents were measured in the K1 cell line using the DNA relaxation assay, the P4 unknotting assay, and immunoblotting, respectively. WR-1065 was ineffective in modifying topo I activity, but it did reduce topo IIa activity by an average of 50 percent. The magnitude of topo IIa protein content, however, was not affected by these exposure conditions. Cell cycle effects were monitored by the method of flow cytometry. Exposure of cells to 4 mM WR-1065 for a period of up to 6 h resulted in a buildup of cells in the G2 compartment. However, in contrast to topo II inhibitors used in chemotherapy, WR-1065 is an effective radioprotector agent capable of protecting against both radiation-induced cell lethality and mutagenesis. One of several mechanisms of radiation protection attributed to aminothiol compounds such as WR-1065 has been their ability to affect endogenous enzymatic reactions involved in DNA synthesis, repair, and cell cycle progression. These results are consistent with such a proposed mechanism and demonstrate in particular a modifying effect by 2-[(aminopropyl)amino]ethanethiol on type II topoisomerase, which is involved in DNA synthesis.

  18. Interspecies comparison of the tissue distribution of WR-2721, a radioprotective drug

    International Nuclear Information System (INIS)

    Washburn, L.C.; Rafter, J.J.; Hayes, R.L.; Yuhas, J.M.

    1975-01-01

    Pre-irradiation intravenous administration of the radioprotective drug S-2-[3-aminopropylamino]ethylphosphorothioic acid (WR-2721) has potential value in radiotherapy because it doubles the radiation resistance of normal mouse tissues while affording only minimal protection to tumors. Deficient deposition of WR- 2721 in tumor tissue has recently been demonstrated and this is thought to be a major reason for the preferential protection of normal tissues by the drug. Data originally obtained in studies using the mouse and rat indicated that the tissue distribution of WR-2721 was possibly more closely related to dose per unit surface area than to dose per unit weight. To test this hypothesis an interspecies comparison of the tissue distribution of 35 S-labeled WR-2721 was carried out in normal mice, rats, rabbits, and dogs at 15 and 30 minutes after intravenous administration. Results suggest that the surface area and body weight exert equal effects on the tissue concentration of WR-2721. The results further suggest that lower absolute doses of WR-2721 in the human, possibly as low as 20 mg/kg, may provide a radioprotective effect equivalent to that produced from 100 mg/kg in the mouse, i.e., a 50 to 80 percent increase in radiation resistance (CH)

  19. Comparative study of the radioprotective effects of cysteamine, WR-2721, and WR-1065 in cultured human cells

    International Nuclear Information System (INIS)

    Purdie, J.W.

    1979-01-01

    The compounds, 2-mercaptoethylamine (cysteamine), S-2-(3-aminopropylamino)ethylphosphorothioic acid (WR-2721), and N-(2-mercaptoethyl)-1,3-diaminopropane (WR-1065) were tested for toxicity and radioprotective effect in cultured human cells using viability (reproductive death) as an indicator. WR-2721 and WR-1065 had no harmful effect at concentrations of 4 and 10 mM for periods up to 3 hr whereas cysteamine was toxic if left in contact with the cells for more than 30 min. The response of the cells to radiation was measured after a 30-min treatment with 4 mM of each protective agent. Survival curves were constructed and the following dose reduction factors (DRFs) were calculated: WR-2721, 1.3; cysteamine, 2.3; WR-1065, 2.9. Increasing the concentration of protective agent did not increase the DRF under these conditions except in the case of cysteamine. Extending the period of treatment with drug before irradiation increased the DRF for WR-2721 and WR-1065; values up to 1.8 and 3.4 were obtained with 10 mM WR-2721 and WR-1065, respectively. With these two compounds, the rate of development of protection with time is almost independent of concentration until the maximum is attained; it is probably controlled by the rate of transport across the cell membrane, in the case of WR-1065, and by the rate of hydrolysis of WR-2721

  20. Passive permeability of salicylic acid in renal proximal S2 and S3 tubules

    International Nuclear Information System (INIS)

    Chatton, J.Y.; Roch-Ramel, F.

    1991-01-01

    The role of nonionic diffusion in the transport of salicylic acid across rabbit proximal S2 and S3 segments was investigated using the in vitro isolated perfused tubule technique. The [ 14 C] salicylic acid apparent reabsorptive permeability (P'I-b, 10(-5) cm/s) was measured at 19 degrees C with luminal solutions kept at different pH and bath maintained at pH 7.4. In S2 tubules, P'I-b was 25.0 +/- 3.5 when luminal pH was 6.0; P'I-b decreased to 8.1 +/- 1.4 and to 4.4 +/- 1.2 at a luminal pH of 6.5 and 7.0, respectively. In S3 tubules, P'I-b was 17.6 +/- 2.4, 5.3 +/- 1.1 and 3.4 +/- 1.1 at a luminal pH of 6.0, 6.5 and 7.0, respectively. There was a close correlation between P'I-b and the calculated proportion of nonionized salicylic acid present at each pH, indicating that only the nonionized molecule could diffuse in our conditions. We calculated the apparent permeability of nonionic salicylic acid and found 0.248 +/- 0.032 cm/s for S2 and 0.176 +/- 0.022 cm/s for S3 tubules. These calculated permeabilities were independent of pH

  1. Inhibition of topoisomerase II activity in repair-proficient CHO K1 cells by 2-[(aminopropyl)amino]ethanethiol (WR-1065)

    International Nuclear Information System (INIS)

    Grdina, D.J.; Constantinou, A.; Shigematsu, N.

    1992-09-01

    The aminothiol 2-[(aminopropyl)amino]ethanethiol (WR-1065) is the active thiol of the clinically studied radioprotective agent S-2-(3-aminopropylamino) ethylphosphorothioic acid (WR-2721). WR-1065 is an effective radiation protector under in vitro conditions when it is administered 30 min prior to radiation exposure at a concentration of 4 mM to repair-proficient Chinese hamster ovary Kl cells (i.e., a dose modification factor of 1.4). In contrast, the DNA double-strand break, repair-deficient Chinese hamster ovary xrs-5 cell line is not protected under these conditions (i.e., a dose modification factor of 1.0). Topoisomerase (topo) I and II activities and protein contents were measured in both Kl and xrs-5 cell lines and were found to be similar in magnitude. Neither exposure to radiation, to WR-1065, or to both affected these variables in xrs-5 cells. WR 1065 was effective, however, in reducing topo 11 activity by a factor of 2 in the repair-proficient Kl cell line. Topo II protein content, however, was not affected by these exposure conditions. One of several mechanisms of radiation protection attributed to aminothiol compounds has been their ability to affect enzymatic reactions involved in DNA synthesis, repair, and cell cycle progression. These results demonstrate a modifying effect by 2-[(aminopropyl)amino]ethanethiol on a specific nuclear enzyme (i.e., type H topoisomerase), which is involved in DNA synthesis. These results also suggest that differences do exist between the topo 11 enzymes isolated from the parent repair-proficient Kl and the DNA double-strand break, repair-deficient xrs-5 mutant cell lines

  2. Inhibition of topoisomerase II activity in repair-proficient CHO K1 cells by 2-[(aminopropyl)amino]ethanethiol (WR-1065)

    Energy Technology Data Exchange (ETDEWEB)

    Grdina, D.J.; Constantinou, A.; Shigematsu, N.

    1992-09-01

    The aminothiol 2-[(aminopropyl)amino]ethanethiol (WR-1065) is the active thiol of the clinically studied radioprotective agent S-2-(3-aminopropylamino) ethylphosphorothioic acid (WR-2721). WR-1065 is an effective radiation protector under in vitro conditions when it is administered 30 min prior to radiation exposure at a concentration of 4 mM to repair-proficient Chinese hamster ovary Kl cells (i.e., a dose modification factor of 1.4). In contrast, the DNA double-strand break, repair-deficient Chinese hamster ovary xrs-5 cell line is not protected under these conditions (i.e., a dose modification factor of 1.0). Topoisomerase (topo) I and II activities and protein contents were measured in both Kl and xrs-5 cell lines and were found to be similar in magnitude. Neither exposure to radiation, to WR-1065, or to both affected these variables in xrs-5 cells. WR 1065 was effective, however, in reducing topo 11 activity by a factor of 2 in the repair-proficient Kl cell line. Topo II protein content, however, was not affected by these exposure conditions. One of several mechanisms of radiation protection attributed to aminothiol compounds has been their ability to affect enzymatic reactions involved in DNA synthesis, repair, and cell cycle progression. These results demonstrate a modifying effect by 2-[(aminopropyl)amino]ethanethiol on a specific nuclear enzyme (i.e., type H topoisomerase), which is involved in DNA synthesis. These results also suggest that differences do exist between the topo 11 enzymes isolated from the parent repair-proficient Kl and the DNA double-strand break, repair-deficient xrs-5 mutant cell lines.

  3. The effect of 2-[(aminopropyl)amino] ethanethiol on fission-neutron-induced DNA damage and repair.

    Science.gov (United States)

    Grdina, D. J.; Sigdestad, C. P.; Dale, P. J.; Perrin, J. M.

    1989-01-01

    The effect(s) of the radioprotector 2-[(aminopropyl)amino] ethanethiol (WR 1065) on fission-neutron-induced DNA damage and repair in V79 Chinese hamster cells was determined by using a neutral filter elution procedure (pH 7.2). When required, WR1065, at a final working concentration of 4 mM, was added to the culture medium, either 30 min before and during irradiation with fission spectrum neutrons (beam energy of 0.85 MeV) from the JANUS research reactor, or for selected intervals of time following exposure. The frequency of neutron-induced DNA strand breaks as measured by neutral elution as a function of dose equalled that observed for 60Co gamma-ray-induced damage (relative biological effectiveness of one). In contrast to the protective effect exhibited by WR1065 in reducing 60Co-induced DNA damage, WR1065 was ineffective in reducing or protecting against induction of DNA strand breaks by JANUS neutrons. The kinetics of DNA double-strand rejoining were measured following neutron irradiation. In the absence of WR1065, considerable DNA degradation by cellular enzymes was observed. This process was inhibited when WR1065 was present. These results indicate that, under the conditions used, the quality (i.e. nature), rather than quantity, of DNA lesions (measured by neutral elution) formed by neutrons was significantly different from that formed by gamma-rays. PMID:2667608

  4. The effect of 2-[(aminopropyl)amino] ethanethiol (WR 1065) on radiation-induced DNA damage and repair and cell progression in V79 cells

    International Nuclear Information System (INIS)

    Grdina, D.J.; Nagy, B.

    1986-01-01

    The radioprotector 2-[(aminopropyl)amino] ethanethiol (WR 1065) was investigated with respect to its ability to affect radiation-induced DNA damage and repair in V79 cells. At a concentration of 4mM, WR 1065 protected against the formation of single strand breaks (SSB), when present during irradiation. The protector appeared, however, to inhibit the subsequent postirradiation repair or rejoining of SSB. While repair was complete within 24h, the protector reduced the rate of repair by a factor of 3. This inhibitory effect on the rate of repair did not correlate with either measured differences in cell survival or mutagenesis. WR 1065 present in the growth medium inhibited the progression of cells through S-phase, and cell-doubling time following a 3h exposure to the protector was increased from 11 to 18h. These data are consistent with the property of thiols to inhibit DNA polymerase activity. It was concluded that, while the presence of WR 1065 during irradiation reduced SSB-DNA damage, its effect on the subsequent rejoining of these breaks could not be correlated with its observed effect on protecting against radiation-induced mutagenesis. (author)

  5. Structure-activity relationship of daptomycin analogues with substitution at (2S, 3R) 3-methyl glutamic acid position.

    Science.gov (United States)

    Lin, Du'an; Lam, Hiu Yung; Han, Wenbo; Cotroneo, Nicole; Pandya, Bhaumik A; Li, Xuechen

    2017-02-01

    Daptomycin is a highly effective lipopeptide antibiotic against Gram-positive pathogens. The presence of (2S, 3R) 3-methyl glutamic acid (mGlu) in daptomycin has been found to be important to the antibacterial activity. However the role of (2S, 3R) mGlu is yet to be revealed. Herein, we reported the syntheses of three daptomycin analogues with (2S, 3R) mGlu substituted by (2S, 3R) methyl glutamine (mGln), dimethyl glutamic acid and (2S, 3R) ethyl glutamic acid (eGlu), respectively, and their antibacterial activities. The detailed synthesis of dimethyl glutamic acid was also reported. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Phase I trials of WR2721 in combination with radiation therapy and with the alkylating agents cyclophosphamide and cis-platinum

    Energy Technology Data Exchange (ETDEWEB)

    Kligerman, M.M.; Blumberg, A.L.; Glick, J.H.; Nelson, D.F.; Glover, D.; Yuhas, J.M.; Amols, H.I.; Goodman, R.L.

    Three phase I trials of the radioprotector S-2-(3-aminopropylamino) ethylphosphorothioic acid (WR2721) have accessed 60 patients. Study 1 is devised to determine the maximum tolerated dose (MTD) of a single dose of the protector 15 to 30 minutes before a single radiation treatment of a size used routinely in palliative management. Study 2 plans to determine the MTD for up to 15 daily doses of the drug over 3 weeks during palliative radiotherapy. Also, the multipe-dose study will establish the MTD before palliative irradiation for fewer than five fractions a week. Study 3 uses the existing single-dose MTD determined in Study 1 as pretreatment 15 to 30 minutes before cyclophosphamide or cis-platinum. Toxic symptoms include emesis, hypotension, hypertension, somnolence, and sneezing. Only one serious episode of hypotension, considered idiosyncratic, and one instance of moderate to severe vomiting have occurred. Forty-one patients have been entered in Study 1 and a dose of 600 mg/m2 has been reached. The next step is to proceed to the planned highest level of 740 mg/m2. Of five patients in the multiple-dose study, one has been given, without toxicity, WR2721 at the level of 100 mg/m2 for 15 fractions over 3 weeks. Fourteen patients are accessed to the alkylating agent study. Using protector doses of 450 mg/m2, a cyclophosphamide level of 1500 mg/m2 has been accomplished. However, two of three patients who received 450 mg/m2 of WR2721 before 120 mg/m2 of cis-platinum have shown moderate elevation of the serum creatinine, both of which returned to normal.

  7. Phase I trials of WR2721 in combination with radiation therapy and with the alkylating agents cyclophosphamide and cis-platinum

    International Nuclear Information System (INIS)

    Kligerman, M.M.; Blumberg, A.L.; Glick, J.H.; Nelson, D.F.; Glover, D.; Yuhas, J.M.; Amols, H.I.; Goodman, R.L.

    1981-01-01

    Three phase I trials of the radioprotector S-2-(3-aminopropylamino) ethylphosphorothioic acid (WR2721) have accessed 60 patients. Study 1 is devised to determine the maximum tolerated dose (MTD) of a single dose of the protector 15 to 30 minutes before a single radiation treatment of a size used routinely in palliative management. Study 2 plans to determine the MTD for up to 15 daily doses of the drug over 3 weeks during palliative radiotherapy. Also, the multipe-dose study will establish the MTD before palliative irradiation for fewer than five fractions a week. Study 3 uses the existing single-dose MTD determined in Study 1 as pretreatment 15 to 30 minutes before cyclophosphamide or cis-platinum. Toxic symptoms include emesis, hypotension, hypertension, somnolence, and sneezing. Only one serious episode of hypotension, considered idiosyncratic, and one instance of moderate to severe vomiting have occurred. Forty-one patients have been entered in Study 1 and a dose of 600 mg/m2 has been reached. The next step is to proceed to the planned highest level of 740 mg/m2. Of five patients in the multiple-dose study, one has been given, without toxicity, WR2721 at the level of 100 mg/m2 for 15 fractions over 3 weeks. Fourteen patients are accessed to the alkylating agent study. Using protector doses of 450 mg/m2, a cyclophosphamide level of 1500 mg/m2 has been accomplished. However, two of three patients who received 450 mg/m2 of WR2721 before 120 mg/m2 of cis-platinum have shown moderate elevation of the serum creatinine, both of which returned to normal

  8. Adverse effects of the radioprotector WR2721

    International Nuclear Information System (INIS)

    Cairnie, A.B.

    1983-01-01

    S-2-(3-Aminopropylamino)ethylphosphorothioic acid (WR2721) has radioprotective properties, but it is also toxic - in man it causes nausea and vomiting. Since radiation also causes nausea and vomiting it is important to know whether WR2721 would increase or decrease the likelihood of nausea and vomiting after radiation. This question was investigated in rats using the phenomenon of aversion to the taste of saccharin, which is readily inducible and is understood to be controlled in rats by the same pathways that control nausea and vomiting in man. The taste aversion was induced by giving 0.2 Gy 60 Co γ radiation 30 min after drinking 0.1% saccharin, or WR2721 immediately after the saccharin, or giving both radiation and WR2721. There were appropriate controls. In sham-irradiated rats, WR2721 (40 or 200 mg/kg, but not 8 mg/kg) produced a significant taste aversion. When WR2721 (40 or 200 mg/kg) was given immediately after the saccharin to irradiated rats it increased the taste aversion significantly, but it did not have any effect at 8 mg/kg. It was concluded that at doses which were optimal for radioprotection (approx.200 mg/kg) or lower, WR2721 increased in rats the taste aversion induced by radiation. By inference if conditioned taste aversion is an appropriate paradigm, WR2721 would increase nausea and vomiting in man induced by radiation

  9. The radioprotector WR-2721 reduces neutron-induced mutations at the hypoxanthine-guanine phosphoribosyl transferase locus in mouse splenocytes when administered prior to or following irradiation

    International Nuclear Information System (INIS)

    Grdina, D.J.; Basic, I.

    1992-01-01

    An in vitro T-lymphocyte cloning technique has been applied to study the effects of JANUS fission-spectrum neutron irradiation and the radioprotector S-2-(3-aminopropylamino) ethylphosphorothioic acid (WR-2721) on the subsequent development of somatic mutations at the hypoxanthine-guanine phosphoribosyl transferase (hprt) locus in hybrid B6CF1 male mice. In control studies performed to establish an in vitro cloning technique, the mutant frequencies of splenic T-lymphocytes, as a result of exposure to a 100 cGy dose of neutrons, increased with time from a control level of 9 x 10 -7 to a maximum value of 1.7 x 10 -5 at 56 days following irradiation. Between 56 and 150 days after irradiation, mutant frequencies were observed to plateau and remain stable. All subsequent determinations were performed at 56 days following the experimental treatment of animals. WR-2721 at a dose of 400 mg/kg was effective in protecting against the induction of hprt mutants (i.e. a mutant frequency reduction factor, MFRF) following the largest dose of neutrons used (i.e. 150 cGy). The antimutagenic effectiveness of WR-2721 administered 30 min prior to irradiation was unaffected, even when the dose was reduced to 200 mg/kg. These findings confirm our earlier report using the radioprotector N-(2-mercaptoethyl)-1,2-diaminopropane (WR-1065) under in vitro conditions, and demonstrate that these agents can be used as effective antimutagens even when they are administered up to 3 h following radiation exposure. (Author)

  10. Toxicity studies on the radioprotective agent WR-2721 in CDF1 mice and beagle dogs

    International Nuclear Information System (INIS)

    Palmer, T.E.; Glaza, S.M.; Dickie, B.C.; Weltman, R.H.; Greenspun, K.S.

    1985-01-01

    WR-2721, S-2-(3-aminopropylamino)ethylphosphorothioic acid, is used extensively to protect normal cells during the irradiation of neoplastic cells. Dose levels for human radiotherapy are based on results obtained from laboratory animal lethality and toxicity studies. WR-2721 was administered intravenously to CDF1 mice and beagle dogs. Single dose lethality studies in mice showed the average 1/10 of the lethal dose, the median lethal dose and 9/10 the lethal dose to be 508 (1523 mg/m2), 589 (1766 mg/m2), and 682 mg/kg (2047 mg/m2), respectively. The lethal dose for female mice was lower than that for males. The 1/10 lethal dose in mice was slightly toxic to dogs; 1/10 of that dose was nontoxic. The lethal dose for dogs (6000 mg/m2) was higher than that for mice (2000 mg/m2). Clinical signs of toxicosis in the single-dose mouse toxicity study were evident in the 1st week following treatment and declined during the recovery period; signs of toxicosis were transient in dogs. Acute drug-induced pathologic changes included elevated BUN and SGOT levels, lymphoid necrosis, and renal tubular degeneration in mice. These changes were evident in the 1st week following treatment, but had dissipated by study termination. Generalized vascular changes (congestion, hemorrhage, and edema) and renal tubular degeneration occurred in treated dogs that had died or were killed moribund 7 days postinjection. These findings indicate sex-dependent and interspecies variation in the toxicity of WR-2721 with acute, but reversible, pathologic changes

  11. Structure-Activity Relationship Study of Ionotropic Glutamate Receptor Antagonist (2S,3R)-3-(3-Carboxyphenyl)pyrrolidine-2-carboxylic Acid

    DEFF Research Database (Denmark)

    Krogsgaard-Larsen, Niels; Storgaard, Morten; Møller, Charlotte

    2015-01-01

    Herein we describe the first structure-activity relationship study of the broad-range iGluR antagonist (2S,3R)-3-(3-carboxyphenyl)pyrrolidine-2-carboxylic acid (1) by exploring the pharmacological effect of substituents in the 4, 4', or 5' positions and the bioisosteric substitution of the distal...... carboxylic acid for a phosphonic acid moiety. Of particular interest is a hydroxyl group in the 4' position 2a which induced a preference in binding affinity for homomeric GluK3 over GluK1 (Ki = 0.87 and 4.8 μM, respectively). Two X-ray structures of ligand binding domains were obtained: 2e in GluA2-LBD...... and 2f in GluK1-LBD, both at 1.9 Å resolution. Compound 2e induces a D1-D2 domain opening in GluA2-LBD of 17.3-18.8° and 2f a domain opening in GluK1-LBD of 17.0-17.5° relative to the structures with glutamate. The pyrrolidine-2-carboxylate moiety of 2e and 2f shows a similar binding mode as kainate...

  12. Pharmacology of (S)-homoquisqualic acid and (S)-2-amino-5-phosphonopentanoic acid [(S)-AP5] at cloned metabotropic glutamate receptors

    DEFF Research Database (Denmark)

    Bräuner-Osborne, Hans; Krogsgaard-Larsen, P

    1998-01-01

    1 In this study we have determined the pharmacological profile of (S)-quisqualic acid, (S)-2-amino-4-phosphonobutyric acid ((S)-AP4) and their higher homologues (S)-homoquisqualic acid, (S)-2-amino-5-phosphonopentanoic acid ((S)-AP5), respectively, and (R)-AP5 at subtypes of metabotropic (S)-glutamic...... demonstrate that incorporation of an additional carbon atom into the backbone of (S)-glutamic acid and its analogues, to give the corresponding homologues, and replacement of the terminal carboxyl groups by isosteric acidic groups have profound effects on the pharmacological profiles at mGlu receptor subtypes...... acid (mGlu) receptors expressed in Chinese hamster ovary cells. 2 (S)-Quisqualic acid was a potent mGlu1/mGlu5 agonist (EC50 values of 1.1 microM and 0.055 microM, respectively) showing no activity at mGlu2 and weak agonism at mGlu4 (EC50 approximately 1000 microM). 3 (S)-Homoquisqualic acid displayed...

  13. Stereospecific enzymatic transformation of alpha-ketoglutarate to (2S,3R)-3-methyl glutamate during acidic lipopeptide biosynthesis.

    Science.gov (United States)

    Mahlert, Christoph; Kopp, Florian; Thirlway, Jenny; Micklefield, Jason; Marahiel, Mohamed A

    2007-10-03

    The acidic lipopeptides, including the calcium-dependent antibiotics (CDA), daptomycin, and A54145, are important macrocyclic peptide natural products produced by Streptomyces species. All three compounds contain a 3-methyl glutamate (3-MeGlu) as the penultimate C-terminal residue, which is important for bioactivity. Here, biochemical in vitro reconstitution of the 3-MeGlu biosynthetic pathway is presented, using exclusively enzymes from the CDA producer Streptomyces coelicolor. It is shown that the predicted 3-MeGlu methyltransferase GlmT and its homologues DptI from the daptomycin producer Streptomyces roseosporus and LptI from the A54145 producer Streptomyces fradiae do not methylate free glutamic acid, PCP-bound glutamate, or Glu-containing CDA in vitro. Instead, GlmT, DptI, and LptI are S-adenosyl methionine (SAM)-dependent alpha-ketoglutarate methyltransferases that catalyze the stereospecific methylation of alpha-ketoglutarate (alphaKG) leading to (3R)-3-methyl-2-oxoglutarate. Subsequent enzyme screening identified the branched chain amino acid transaminase IlvE (SCO5523) as an efficient catalyst for the transformation of (3R)-3-methyl-2-oxoglutarate into (2S,3R)-3-MeGlu. Comparison of reversed-phase HPLC retention time of dabsylated 3-MeGlu generated by the coupled enzymatic reaction with dabsylated synthetic standards confirmed complete stereocontrol during enzymatic catalysis. This stereospecific two-step conversion of alphaKG to (2S,3R)-3-MeGlu completes our understanding of the biosynthesis and incorporation of beta-methylated amino acids into the nonribosomal lipopeptides. Finally, understanding this pathway may provide new possibilities for the production of modified peptides in engineered microbes.

  14. Molecular pharmacology of the AMPA agonist, (S)-2-amino-3-(3-hydroxy-5-phenyl-4-isoxazolyl)propionic acid [(S)-APPA] and the AMPA antagonist, (R)-APPA

    DEFF Research Database (Denmark)

    Ebert, B; Madsen, U; Lund, Trine Meldgaard

    1994-01-01

    )-APPA, whereas (R)-APPA is a non-N-methyl-D-aspartic acid (non-NMDA) receptor antagonist showing preferential AMPA blocking effects. In agreement with classical theories for competitive interaction between agonists and antagonists, the efficacy of depolarizations produced by (S)-APPA in the rat cortical wedge......The heterocyclic analogue of (S)-glutamic acid, (S)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid [(S)-AMPA] is a potent and selective AMPA receptor agonist, whereas the enantiomeric compound, (R)-AMPA, is virtually inactive. We have previously characterized (RS)-2-amino-3-(3-hydroxy-5......-phenyl-4-isoxazolyl)propionic acid [(RS)-APPA] as a partial AMPA receptor agonist showing about 60% of the efficacy of (RS)-AMPA. This partial agonism produced by (RS)-APPA is, however, only apparent, since resolution of (RS)-APPA has now been shown to provide the full AMPA receptor agonist, (S...

  15. 2-Amino-3-(3-hydroxy-1,2,5-thiadiazol-4-yl)propionic acid

    DEFF Research Database (Denmark)

    Johansen, Tommy N; Janin, Yves L; Nielsen, Birgitte

    2002-01-01

    In order to identify new subtype-selective (S)-glutamate (Glu) receptor ligands we have synthesized (RS)-2-amino-3-(3-hydroxy-1,2,5-thiadiazol-4-yl)propionic acid [(RS)-TDPA]. Resolution of (RS)-TDPA by chiral chromatography was performed using a Crownpac CR(+) column affording (R)- and (S......)-TDPA of high enantiomeric purity (enantiomeric excess=99.9%). An X-ray crystallographic analysis revealed that the early eluting enantiomer has R-configuration. Both enantiomers showed high affinity as well as high agonist activity at (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA...... a remarkably low AMPA receptor stereoselectivity, (S)-TDPA showing the highest affinity and (R)-TDPA the most potent agonist activity. In addition, (S)-TDPA was shown to interact with synaptosomal Glu uptake sites displacing [(3)H](R)-aspartic acid (IC(50 ) approximately 390 microM). An enantiospecific...

  16. Kinetics of Ni3S2 sulfide dissolution in solutions of sulfuric and hydrochloric acids

    Science.gov (United States)

    Palant, A. A.; Bryukvin, V. A.; Vinetskaya, T. N.; Makarenkova, T. A.

    2008-02-01

    The kinetics of Ni3S2 sulfide (heazlewoodite) dissolution in solutions of hydrochloric and sulfuric acids is studied. The process under study in the temperature range of 30 90°C is found to occur in a kinetic regime and is controlled by the corresponding chemical reactions of the Ni3S2 decomposition by solutions of inorganic acids ( E a = 67 92 kJ/mol, or 16 22 kcal/mol). The only exception is the Ni3S2-HCl system at elevated temperatures (60 90°C). In this case, the apparent activation energy decreases sharply to 8.8 kJ/mol (2.1 kcal/mol), which is explained by the catalytic effect of gaseous chlorine formed under these conditions. The studies performed are related to the physicochemical substantiation of the hydrometallurgical processing of the copper-nickel converter mattes produced in the industrial cycle of the Norilsk Mining Company.

  17. Copper-Assisted Oxidative Trifluoromethylthiolation of 2,3-Allenoic Acids with AgSCF3.

    Science.gov (United States)

    Pan, Shen; Huang, Yangen; Xu, Xiu-Hua; Qing, Feng-Ling

    2017-09-01

    The oxidative trifluoromethylthiolation of 2,3-allenoic acids with AgSCF 3 in the presence of (NH 4 ) 2 S 2 O 8 and catalytic copper salt was investigated. A series of 4-aryl-2,3-allenoic acids underwent radical trifluoromethylthiolation/intramolecular cyclization to afford β-trifluoromethylthiolated butenolides, which were conveniently transformed into trifluoromethylthiolated furan derivatives. In contrast, 2-monosubstituted 2,3-allenoic acids were converted into the corresponding 3,4-bis(trifluoromethylthio)but-2-enoic-acids under similar reaction conditions.

  18. Excitatory amino acid receptor ligands: resolution, absolute stereochemistry, and enantiopharmacology of 2-amino-3-(4-butyl-3-hydroxyisoxazol-5-yl)propionic acid

    DEFF Research Database (Denmark)

    Johansen, T N; Ebert, B; Bräuner-Osborne, Hans

    1998-01-01

    (RS)-2-Amino-3-(4-butyl-3-hydroxyisoxazol-5-yl)propionic acid (Bu-HIBO, 6) has previously been shown to be an agonist at (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) receptors and an inhibitor of CaCl2-dependent [3H]-(S)-glutamic acid binding (J. Med. Chem. 1992, 35, 3512......-3519). To elucidate the pharmacological significance of this latter binding affinity, which is also shown by quisqualic acid (3) but not by AMPA, we have now resolved Bu-HIBO via diastereomeric salt formation using the diprotected Bu-HIBO derivative 11 and the enantiomers of 1-phenylethylamine (PEA). The absolute...... equipotent as inhibitors of CaCl2-dependent [3H]-(S)-glutamic acid binding, neither enantiomer showed significant affinity for the synaptosomal (S)-glutamic acid uptake system(s). AMPA receptor affinity (IC50 = 0.48 microM) and agonism (EC50 = 17 microM) were shown to reside exclusively in the S...

  19. Discovery of a New Class of Ionotropic Glutamate Receptor Antagonists by the Rational Design of (2S,3R)-3-(3-Carboxyphenyl)-pyrrolidine-2-carboxylic Acid

    DEFF Research Database (Denmark)

    Larsen, Ann Møller; Venskutonyte, Raminta; Valadés, Elena Antón

    2011-01-01

    The kainic acid (KA) receptors belong to the class of glutamate (Glu) receptors in the brain and constitute a promising target for the treatment of neurological and/ or psychiatric diseases such as schizophrenia, major depression, and epilepsy. Five KA subtypes have been identified and named GluK1......-5. In this article, we present the discovery of (2S,3R)-3-(3-carboxyphenyl)-pyrrolidine-2-carboxylic acid (1) based on a rational design process. Target compound 1 was synthesized by a stereoselective strategy in 10 steps from commercially available starting materials. Binding affinities of 1 at native ionotropic...

  20. Corrosion inhibitors for aluminium in hydrochloric acid. Vanilline on aluminium 2S, 57S and 65S

    Energy Technology Data Exchange (ETDEWEB)

    Desai, M.N.

    1972-12-01

    So far, the only aldehyde reported in literature for the inhibition of the corrosion of aluminum in hydrochloric acid, is furfuraldehyde. This study reports vanilline as a corrosion inhibitor for aluminum alloys 2S, 57S, and 65S. These specifications for the alloys are listed. The influence of inhibitor concentration and time on inhibitor efficiency is given in tabular data and illustrated graphically. The corrosion of aluminum alloys 2S, 57S, and 65S increases with time and hydrochloric acid concentration. Polarization measurements indicate that the corrosion of aluminum alloys in hydrochloric acid is cathodically controlled. The behavior of vanilline as a corrosion inhibitor is very interesting. In 2.0N solution of hydrochloric acid, vanilline affords nearly complete protection (97 to 99%) to all the 3 aluminum alloys investigated up to 60 min. However, in 1.0N solutions of hydrochloric acid, the corrosion of aluminum 2S is severely accelerated by vanilline.

  1. Rational design and enantioselective synthesis of (1R,4S,5R,6S)-3-azabicyclo[3.3.0]octane-4,6-dicarboxylic acid - a novel inhibitor at human glutamate transporter subtypes 1, 2, and 3

    DEFF Research Database (Denmark)

    Bunch, Lennart; Nielsen, Birgitte; Jensen, Anders A.

    2006-01-01

    The natural product kainic acid is used as template for the rational design of a novel conformationally restricted (S)-glutamic acid (Glu) analogue, (1R,4S,5R,6S)-3-azabicyclo[3.3.0]octane-4,6-dicarboxylic acid (1a). The target structure 1a was synthesized from commercially available (S)-pyroglut......The natural product kainic acid is used as template for the rational design of a novel conformationally restricted (S)-glutamic acid (Glu) analogue, (1R,4S,5R,6S)-3-azabicyclo[3.3.0]octane-4,6-dicarboxylic acid (1a). The target structure 1a was synthesized from commercially available (S...

  2. Developmental Toxicity of (4S-2- (4-hydroxy-3-methoxyphenyl thiazolidine-4-carboxylic acid in Zebrafish ( Danio rerio

    Directory of Open Access Journals (Sweden)

    Cansu Akbulut

    2017-08-01

    Full Text Available ABSTRACT (4S-2-(4-hydroxy-3-methoxyphenylthiazolidine-4-carboxylic acid is new synthesized substance obtained from cysteine and valine. Thiazolidine derivates have important biological responses so scientists work intensively on these compounds in recent years. It is obvious that thiazolidine contained compounds will be used in future in the pharmaceutical industry to treat important diseases. Median lethal concentrations (LC50 for 48 h and 96 h were found as 1.106±0.052 mM and 0.804mM ± 0.102 respectively. According to LC50, exposure doses were determined as control, 0.4 mM, 0.2 mM and 0.1 mM (4S-2-(4-hydroxy-3-methoxyphenylthiazolidine-4-carboxylic acid. Developmental toxicity and apoptotic features on zebrafish development were evaluated in this study. The results of this study indicate that (4S-2-(4-hydroxy-3-methoxyphenylthiazolidine-4-carboxylic acid exposure cause developmental defects like pericardial edema, bent spine, tail malformation, blood accumulation, yolk sac edema but on the other hand concentration-dependent decrease in apoptotic rate. Likewise, concentration-dependent decrease in hatching and increase in mortality of embryos were also detected.

  3. 40 CFR 180.1281 - S-Abscisic Acid, (S)-5-(1-hydroxy-2,6,6-trimethyl-4-oxo-1-cyclohex-2-enyl)-3-methyl-penta-(2Z,4E...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false S-Abscisic Acid, (S)-5-(1-hydroxy-2,6... Exemptions From Tolerances § 180.1281 S-Abscisic Acid, (S)-5-(1-hydroxy-2,6,6-trimethyl-4-oxo-1-cyclohex-2... from the requirement of a tolerance is established for residues of S-Abscisic Acid in or on all food...

  4. Effects of daily treatment with a radioprotector WR-2721 on Ehrlich's ascites tumors in mice

    International Nuclear Information System (INIS)

    Ikebuchi, Makoto; Shinohara, Shigeo; Kimura, Hiroshi; Morimoto, Kunio; Shima, Akihiro

    1981-01-01

    Mice were injected daily with a radioprotector WR-2721 (S-2-[3-aminopropyl-amino]ethylphosphorothioic acid) after inoculation with Ehrlich's ascites tumor cells. Increases in weight of mice, volume of ascitic fluid and number of ascitic cells per mouse were reduced by the daily administration of 5 mg/mouse of the drug, indicating a suppressive effect of WR-2721 on growth of ascitic cells. But daily treatment with 5 mg/mouse of WR-2721 caused earlier death of tumor-bearing mice. (author)

  5. 4,4′-Bipyridine–3-(thiophen-3-ylacrylic acid (1/2

    Directory of Open Access Journals (Sweden)

    Malaichamy Sathiyendiran

    2011-10-01

    Full Text Available In the title 1/2 adduct, C10H8N2·2C7H6O2S, the dihedral angle between the pyridine rings is 18.41 (11°. In the thiopheneacrylic acid molecules, the dihedral angles between the respective thiophene and acrylic acid units are 5.52 (17° and 23.92 (9°. In the crystal, the components are linked via O—H...N hydrogen-bonding interactions, forming units of two 3-thiopheneacrylic acid molecules and one 4,4′-bipyridine molecule.

  6. The glutamate receptor GluR5 agonist (S)-2-amino-3-(3-hydroxy-7,8-dihydro-6H-cyclohepta[d]isoxazol-4-yl)propionic acid and the 8-methyl analogue

    DEFF Research Database (Denmark)

    Clausen, Rasmus Prætorius; Naur, Peter; Kristensen, Anders Skov

    2009-01-01

    The design, synthesis, and pharmacological characterization of a highly potent and selective glutamate GluR5 agonist is reported. (S)-2-Amino-3-((RS)-3-hydroxy-8-methyl-7,8-dihydro-6H-cyclohepta[d]isoxazol-4-yl)propionic acid (5) is the 8-methyl analogue of (S)-2-amino-3-(3-hydroxy-7,8-dihydro-6H......-cyclohepta[d]isoxazol-4-yl)propionic acid ((S)-4-AHCP, 4). Compound 5 displays an improved selectivity profile compared to 4. A versatile stereoselective synthetic route for this class of compounds is presented along with the characterization of the binding affinity of 5 to ionotropic glutamate receptors (i......GluRs). Functional characterization of 5 at cloned iGluRs using a calcium imaging assay and voltage-clamp recordings show a different activation of GluR5 compared to (S)-glutamic acid (Glu), kainic acid (KA, 1), and (S)-2-amino-3-(3-hydroxy-5-tert-butyl-4-isoxazolyl)propionic acid ((S)-ATPA, 3) as previously...

  7. S3b amino acid substitutions and ancillary subunits alter the affinity of Heteropoda venatoria toxin 2 for Kv4.3.

    Science.gov (United States)

    DeSimone, Christopher V; Lu, YiChun; Bondarenko, Vladimir E; Morales, Michael J

    2009-07-01

    Heteropoda venatoria toxin 2 (HpTx2) is an inhibitor cystine knot (ICK)-gating modifier toxin that selectively inhibits Kv4 channels. To characterize the molecular determinants of interaction, we performed alanine scanning of the Kv4.3 S3b region. HpTx2-Kv4.3 interaction had an apparent K(d) value of 2.3 microM. Two alanine mutants in Kv4.3 increased K(d) values to 6.4 microM for V276A and 25 microM for L275A. Simultaneous mutation of both amino acids to alanine nearly eliminated toxin interaction. Unlike Hanatoxin and other well characterized ICK toxins, HpTx2 binding does not require a charged amino acid for interaction. To determine whether the identity of the S3b binding site amino acids altered HpTx2 specificity, we constructed Kv4.3 [LV275IF]. This mutation decreased the K(d) value to 0.54 microM, suggesting that the hydrophobic character of the putative binding site is the most important property for interaction with HpTx2. One mutant, N280A, caused stronger interaction of HpTx2 with Kv4.3; the K(d) value for Kv4.3 [N280A] was 0.26 microM. To understand Kv4.3-based transient outward currents in native tissues, we tested the affinity of HpTx2 for Kv4.3 coexpressed with KChIP2b. The toxin's K(d) value for Kv4.3 + KChIP2b was 0.95 microM. KChIP2b stabilizes the closed state of Kv4.3, suggesting that the increased toxin affinity is due to increased stabilization of the closed state. These data show that HpTx2 binding to Kv4.3 has aspects in common with other ICK gating modifier toxins but that the interventions that increase toxin affinity suggest flexibility toward channel binding that belies its unusual specificity for Kv4 channels.

  8. Selective agonists at group II metabotropic glutamate receptors: synthesis, stereochemistry, and molecular pharmacology of (S)- and (R)-2-amino-4-(4-hydroxy[1,2,5]thiadiazol-3-yl)butyric acid

    DEFF Research Database (Denmark)

    Clausen, Rasmus P; Bräuner-Osborne, Hans; Greenwood, Jeremy R

    2002-01-01

    Homologation of analogues of the central excitatory neurotransmitter glutamic acid (Glu), in which the distal carboxy group has been bioisosterically replaced by acidic heterocyclic units, has previously provided subtype selective ligands for metabotropic Glu receptors (mGluRs). The (S......)-form of the 1,2,5-thiadiazol-3-ol Glu analogue, 2-amino-3-(4-hydroxy[1,2,5]thiadiazol-3-yl)propionic acid (TDPA, 6), is an 2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) receptor agonist, which in addition stereospecifically activates group I mGluRs. We have now synthesized the (S)- and (R......)-forms of 2-amino-4-(4-hydroxy[1,2,5]thiadiazol-3-yl)butyric acid (homo-TDPA, 7) and shown that whereas neither enantiomer interacts with AMPA receptors, (S)- and (R)-7 appear to be selective and equipotent agonists at group II mGluRs as represented by the mGluR2 subtype. The activities of (S)- and (R)-7...

  9. HPLC Determination of α-Keto Acids from Human Serum Using 2, 3-Diamino-2, 3- Dimethyl Butane as Derivatizing Reagent

    International Nuclear Information System (INIS)

    Mahar, K.P.; Shar, G.Q.; Khuhawar, M.Y.; Abbasi, K.U.; Azmat, R.; Jameel Ahmed Biag, J.A.

    2013-01-01

    Seven α-keto acids, pyruvic acid (PYR), 2-oxobutyric acid (KB), 3-methyl-2-oxobutyric acid (MKBA), 3-methyl-2-oxovaleric acid (K3MVA), 4-methyl-2-oxovaleric acid (K4MVA), 2-oxoglutaric acid (KG) and Phenyl pyruvic acid (PPY) as derivatives of 2,3-diamino-2,3-dimethybutane (DDB) were separated by HPLC column Zorbax C-18 (4.6x150 mm-id). The compounds were eluted with methanol-water-acetonitrile (40:58:2 V/V/V) with flow rate 1 ml/min. UV detection was carried out by photodiode array at 255 nm. Linear calibration plots were obtained with 0.1 to 60 μg/ml with limits of detection (LoD) within 0.04-0.4 μg/ml. The method was applied for the analysis of α-keto acids from serum of diabetic patients with blood glucose level 430-458 mg/dl and healthy volunteers. The amounts of α-keto acids observed 3.24-9.71 μg/ml with RSD 1.1-1.9 percentage in diabetic patients were higher than healthy volunteer's 0.11-1.3 μg/ml with RSD 0.9-2.6 percentage. (author)

  10. Synthesis of 2-phenyl- and 2,3-diphenyl-quinolin-4-carboxylic acid derivatives

    International Nuclear Information System (INIS)

    Elhadi, S. A.

    2004-09-01

    Quinolin derivatives are a group of compounds known to possess a wide range of biological activities. The chemistry of quinolines together with their corresponding aldehydes were dealt with in chapter one of this study. Special emphasis was given to the chemistry of benzaldehyde. Twenty five 2-phenyl- and 2,3-diphenyl-quinolin-4-carboxylic acid derivatives together with their corresponding intermediates were prepared in this work. Basically, the synthetic design of these compounds arise from the appropriate disconnections of the target 2-phenyl and 2,3-diphenyl-quinolin-4-carboxylic acids. The retro synthesis analysis of these compounds reveals pyruvic acid, aromatic amine and benzaldehyde or phenyl pyruvic acid, aromatic amine and benzaldehyde as possible logical precursors for 2-phenyl-and 2,3-diphenyl- quinoline-4-carboxylic acids respectively. The purity and identities of the synthesized compounds were elucidated through chromatographic and spectroscopic techniques. The compounds were heavily subjected to spectroscopic analysis (UV, IR, GC/MS, 1 H-and 13 C- NMR). The appropriate disconnections and the mechanisms of the corresponding reactions were given and discussed in chapter three. The spectral data were interpreted and correlated with the target structures. The prepared 2-phenyl- and 2,3-diphenyl-quinoline-4-carboxylic acid derivatives were screened for their antibacterial activity. The compounds were tested against the standard bacterial organisms B. subtilis, S. aureus, E. coli and P. vulgaris. Some of these compounds were devoid of antibacterial activity against S. aureus and P. vulgaris, while others showed moderate activity. All of the tested compounds showed an activity against B. subtilis and E. coli. 2,3-diphenyl -6-sulphanilamide-quinolin-4-carboxylic acid showed the highest activity against the four standard tested organisms.(Author)

  11. Synthesis of 2-phenyl- and 2,3-diphenyl-quinolin-4-carboxylic acid derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Elhadi, S A [Department of Chemistry, Faculty of Education, University of Khartoum, Khartoum (Sudan)

    2004-09-01

    Quinolin derivatives are a group of compounds known to possess a wide range of biological activities. The chemistry of quinolines together with their corresponding aldehydes were dealt with in chapter one of this study. Special emphasis was given to the chemistry of benzaldehyde. Twenty five 2-phenyl- and 2,3-diphenyl-quinolin-4-carboxylic acid derivatives together with their corresponding intermediates were prepared in this work. Basically, the synthetic design of these compounds arise from the appropriate disconnections of the target 2-phenyl and 2,3-diphenyl-quinolin-4-carboxylic acids. The retro synthesis analysis of these compounds reveals pyruvic acid, aromatic amine and benzaldehyde or phenyl pyruvic acid, aromatic amine and benzaldehyde as possible logical precursors for 2-phenyl-and 2,3-diphenyl- quinoline-4-carboxylic acids respectively. The purity and identities of the synthesized compounds were elucidated through chromatographic and spectroscopic techniques. The compounds were heavily subjected to spectroscopic analysis (UV, IR, GC/MS, {sup 1}H-and {sup 13}C- NMR). The appropriate disconnections and the mechanisms of the corresponding reactions were given and discussed in chapter three. The spectral data were interpreted and correlated with the target structures. The prepared 2-phenyl- and 2,3-diphenyl-quinoline-4-carboxylic acid derivatives were screened for their antibacterial activity. The compounds were tested against the standard bacterial organisms B. subtilis, S. aureus, E. coli and P. vulgaris. Some of these compounds were devoid of antibacterial activity against S. aureus and P. vulgaris, while others showed moderate activity. All of the tested compounds showed an activity against B. subtilis and E. coli. 2,3-diphenyl -6-sulphanilamide-quinolin-4-carboxylic acid showed the highest activity against the four standard tested organisms.(Author)

  12. Methods of using (1S,3S)-3-amino-4-difluoromethylenyl-1-cyclopentanoic acid

    Energy Technology Data Exchange (ETDEWEB)

    Silverman, Richard B; Dewey, Stephen L; Miller, Steven

    2015-03-03

    (1S,3S)-3-amino-4-difluoromethylenyl-1-cyclopentanoic acid also known as CPP-115 or its pharmaceutically acceptable salts can be used to treat addiction and neurological disorders such as epilepsy without side effects such as visual field defects caused by vigabatrin (Sabril).

  13. Enhanced Synthesis of Alkyl Amino Acids in Miller's 1958 H2S Experiment

    Science.gov (United States)

    Parker, Eric T.; Cleaves, H. James; Callahan, Michael P.; Dworkin, James P.; Glavin, Daniel P.; Lazcano, Antonio; Bada, Jeffrey L.

    2011-01-01

    Stanley Miller's 1958 H2S-containing experiment, which included a simulated prebiotic atmosphere of methane (CH4), ammonia (NH3), carbon dioxide (CO2), and hydrogen sulfide (H2S) produced several alkyl amino acids, including the alpha-, beta-, and gamma-isomers of aminobutyric acid (ABA) in greater relative yields than had previously been reported from his spark discharge experiments. In the presence of H2S, aspariic and glutamic acids could yield alkyl amino acids via the formation of thioimide intermediates. Radical chemistry initiated by passing H2S through a spark discharge could have also enhanced alkyl amino acid synthesis by generating alkyl radicals that can help form the aldehyde and ketone precursors to these amino acids. We propose mechanisms that may have influenced the synthesis of certain amino acids in localized environments rich in H2S and lightning discharges, similar to conditions near volcanic systems on the early Earth, thus contributing to the prebiotic chemical inventory of the primordial Earth.

  14. Toxicological evaluation of the flavour ingredient 4-amino-5-(3-(isopropylamino-2,2-dimethyl-3-oxopropoxy-2-methylquinoline-3-carboxylic acid

    Directory of Open Access Journals (Sweden)

    Amy J. Arthur

    2015-01-01

    Full Text Available A toxicological evaluation of 4-amino-5-(3-(isopropylamino-2,2-dimethyl-3-oxopropoxy-2-methylquinoline-3-carboxylic acid(S9632; CAS 1359963-68-0, a flavour with modifying properties,was completed for the purpose of assessing its safety for use in food and beverage applications. No Phase I biotransformations of S9632 were observed in rat or human microsomes in vitro, and in rat pharmacokinetic studies, the compound was poorly orally bioavailable and rapidly eliminated. S9632 was not found to be mutagenic or clastogenic in vitro, and did not induce micronuclei or indicate interactions with the mitotic spindle in an in vivo mouse micronucleus assay at oral doses up to 2000 mg/kg. In subchronic oral toxicity studies in rats, the NOEL was 100 mg/kg/day (highest dose tested for S9632 when administered as a food ad-mix for 90 consecutive days. Furthermore, S9632 demonstrated a lack of maternal toxicity, as well as adverse effects on fetal morphology at the highest dose tested, providing a NOEL of 1000 mg/kg/day for both maternal toxicity and embryo/fetal development when administered orally during gestation to pregnant rats.

  15. Genotoxicity of meso-2,3-dimercapto succinic acid-coated silver sulfide quantum dot

    Directory of Open Access Journals (Sweden)

    Deniz Özkan Vardar

    2015-06-01

    Full Text Available Nanotecnology products have been used in wide applications in chemistry, electronics, energy generation, and medicine. Despite significant interest in developing quantum dots (QDs for biomedical applications, many researchers are convinced that QDs will never be used for the treatment of patients because of their potential toxicity. In various in vitro cell culture studies, the cytotoxic properties of some QD have been demonstrated and they have been suggested to be toxic in humans. In this study, the cytotoxic properties of Ag2S-(Meso-2,3-Dimercapto Succinic acid nanomaterials in V79 cells (Chinese lung fibroblast cell line were determined by MTT assay. The genotoxic effects of Ag2S-(Meso-2,3-Dimercapto Succinic acid were evaluated by the alkaline single cell gel electrophoresis. The cells were treated with Ag2S-(Meso-2,3-Dimercapto Succinic acid at the concentrations of 5- 2000 µg/ml. No cytotoxic effect of Ag2S-(Meso-2,3-Dimercapto Succinic acid at all concentrations studied was observed. No significant increases in DNA damage were found at the studied concentrations when compared to negative control in V79 cells. In conclusion, further in vitro and in vivo studies are required to determine the safety doses of Ag2S-(Meso-2,3-Dimercapto Succinic acid.

  16. HISTOPATHOLOGICAL EFFECTS OF (4S)-2-(4-HYDROXY-3-METHOXYPHENYL) THIAZOLIDINE-4-CARBOXYLIC ACID ON ZEBRAFISH (Danio rerio) HEART TISSUE

    OpenAIRE

    YÖN, Nazan Deniz; ÖZTÜRK, Burcu; ZENGİN, Mustafa; AKBULUT, Cansu

    2018-01-01

    Examination thehistopathological effects of (4s)-2-(4-hydroxy-3-methoxyphenyl) thiazolidine-4-carboxylicacid on heart tissue of zebrafish were aimed.Introduction:(4S)-2-(4-hydroxy-3-methoxyphenyl) thiazolidine-4-carboxylic acid is newsynthesized substance which obtained from cysteine and valine. Because ofthiazolidine derivates have important biological responses scientist workintensively on these compounds recent years. It is obvious that thiazolidinecontained compounds will be used in futur...

  17. Enhanced visible-light photocatalytic decomposition of 2,4-dichlorophenoxyacetic acid over ZnIn_2S_4/g-C_3N_4 photocatalyst

    International Nuclear Information System (INIS)

    Qiu, Pengxiang; Yao, Jinhua; Chen, Huan; Jiang, Fang; Xie, Xianchuan

    2016-01-01

    Highlights: • A novel flower-on-sheet ZnIn_2S_4/g-C_3N_4 nanocomposite was synthesized. • ZnIn_2S_4/g-C_3N_4 showed high visible light catalytic activity for 2,4-D degradation. • The photocatalytic degradation pathway of 2,4-D was investigated. - Abstract: ZnIn_2S_4/g-C_3N_4 heterojunction photocatalyst was successfully synthesized via a simple hydrothermal method and applied to visible-light photocatalytic decomposition of 2,4-dichlorophenoxyacetic acid (2,4-D) from aqueous phase. The flower-like ZnIn_2S_4 particles were dispersed on the surface of g-C_3N_4 nanosheets in the ZnIn_2S_4/g-C_3N_4 composite. The composite showed higher separation rate of electron-hole pairs as compared to ZnIn_2S_4 and g-C_3N_4. Consequently, the ZnIn_2S_4/g-C_3N_4 composite exhibited enhanced visible light photocatalytic decomposition efficiency of 2,4-D, within 20% ZnIn_2S_4/g-C_3N_4 composite owning the highest photocatalytic efficiency and initial rate. The initial rates of 2,4-D degradation on g-C_3N_4, ZnIn_2S_4, and 20% ZnIn_2S_4/g-C_3N_4 were 1.23, 0.57 and 3.69 mmol/(g_c_a_t h), respectively. The h"+ and O_2"·"− were found to be the dominant active species for 2,4-D decomposition. The photocatalytic degradation pathways of 2,4-D by ZnIn_2S_4/g-C_3N_4 under visible light irradiation were explored. The ZnIn_2S_4/g-C_3N_4 composite displayed high photostability in recycling tests, reflecting its promising potential as an effective visible light photocatalyst for 2,4-D treatment.

  18. Study into non-quasibinary sections of Pr2S3-Bi2S3-Pr2O3 triple system (Bi2S3)0. 45(Pr2O3)0. 55 - (Bi2S3)0. 45(Pr2S3)0. 55 and (Bi2S3)0. 75 (Pr2S3)0. 25 - (Bi2S3)0. 75(Pr2O3)0. 25

    OpenAIRE

    НЕЙМАТОВА А.В.; МАМЕДОВ Ф.М.; БАХТИЯРЛЫ И.Б.

    2016-01-01

    Методами дифференциальнo-термическoго (ДТ), рентгенофазового (РФ), микроструктурного (МС) методов анализа исследованы неквазибинарные разрезы (Bi2S3)0.45(Pr2O3)0.55 (Bi2S3)0.45(Pr2S3)0.55 и (Bi2S3)0.75 (Pr2S3)0.25 (Bi2S3)0.75(Pr2O3)0.25 тройной системы Pr2S3-Bi2S3-Pr2O3 построена диаграмма состояния, определены координанты нони моновариантныхравновесий....

  19. 2-Aminopyrimidine-3,3,3-triphenylpropanoic acid (1/1).

    Science.gov (United States)

    Serafin, Mateusz F; Wheeler, Kraig A

    2007-11-01

    The title bimolecular compound, C(4)H(5)N(3).C(21)H(18)O(2), constructed from 2-aminopyrimidine and 3,3,3-triphenylpropanoic acid, forms a tetramolecular hydrogen-bonded motif via O-H...N, N-H...O and N-H...N contacts. This aggregate organizes to give crystal-packing motifs with hydrophilic and hydrophobic regions.

  20. 2-(3-Hydroxybenzylaminoacetic acid

    Directory of Open Access Journals (Sweden)

    Li-Hua Zhi

    2011-07-01

    Full Text Available There are two independent 2-(3-hydroxybenzylaminoacetic acid molecules, C9H11NO3, in the asymmetric unit of the title compound. The dihedral angle between the benzene rings of the two independent molecules is 58.12 (4°. The crystal packing is stablized by intermolecular O—H...O and N—H...O hydrogen bonds.

  1. Mechanism of inactivation of γ-aminobutyric acid aminotransferase by (1S,3S)-3-amino-4-difluoromethylene-1-cyclopentanoic acid (CPP-115).

    Science.gov (United States)

    Lee, Hyunbeom; Doud, Emma H; Wu, Rui; Sanishvili, Ruslan; Juncosa, Jose I; Liu, Dali; Kelleher, Neil L; Silverman, Richard B

    2015-02-25

    γ-Aminobutyric acid aminotransferase (GABA-AT) is a pyridoxal 5'-phosphate (PLP)-dependent enzyme that degrades GABA, the principal inhibitory neurotransmitter in mammalian cells. When the concentration of GABA falls below a threshold level, convulsions can occur. Inhibition of GABA-AT raises GABA levels in the brain, which can terminate seizures as well as have potential therapeutic applications in treating other neurological disorders, including drug addiction. Among the analogues that we previously developed, (1S,3S)-3-amino-4-difluoromethylene-1-cyclopentanoic acid (CPP-115) showed 187 times greater potency than that of vigabatrin, a known inactivator of GABA-AT and approved drug (Sabril) for the treatment of infantile spasms and refractory adult epilepsy. Recently, CPP-115 was shown to have no adverse effects in a Phase I clinical trial. Here we report a novel inactivation mechanism for CPP-115, a mechanism-based inactivator that undergoes GABA-AT-catalyzed hydrolysis of the difluoromethylene group to a carboxylic acid with concomitant loss of two fluoride ions and coenzyme conversion to pyridoxamine 5'-phosphate (PMP). The partition ratio for CPP-115 with GABA-AT is about 2000, releasing cyclopentanone-2,4-dicarboxylate (22) and two other precursors of this compound (20 and 21). Time-dependent inactivation occurs by a conformational change induced by the formation of the aldimine of 4-aminocyclopentane-1,3-dicarboxylic acid and PMP (20), which disrupts an electrostatic interaction between Glu270 and Arg445 to form an electrostatic interaction between Arg445 and the newly formed carboxylate produced by hydrolysis of the difluoromethylene group in CPP-115, resulting in a noncovalent, tightly bound complex. This represents a novel mechanism for inactivation of GABA-AT and a new approach for the design of mechanism-based inactivators in general.

  2. Chemo-enzymatic synthesis of (2S,4R)-2-amino-4-(3-(2,2-diphenylethylamino)-3-oxopropyl)pentanedioic acid

    DEFF Research Database (Denmark)

    Sagot, Emanuelle; Jensen, Anders A.; Pickering, Darryl S

    2008-01-01

    In the mammalian central nervous system (CNS), the action of sodium dependent excitatory amino acid transporters (EAATs) is responsible for termination of glutamatergic neurotransmission by reuptake of ( S) -glutamate (Glu) from the synaptic cleft. Five EAAT subtypes have been identified, of which...

  3. [(2S-2-(3,5-Dichloro-2-oxidobenzylideneamino-3-(4-hydroxyphenylpropionato-κ3O,N,O′](dimethylformamide-κOcopper(II

    Directory of Open Access Journals (Sweden)

    Hong Liang

    2008-04-01

    Full Text Available In the title complex, [Cu(C16H11Cl2NO4(C3H7NO] , the CuII atom is coordinated by two O atoms and one N atom from the tridentate ligand L2− {LH2 = (2S-[2-(3,5-dichloro-2-hydroxybenzylideneimino]-3-(4-hydroxyphenylpropionic acid} and one O atom from a dimethylformamide molecule, resulting in a slightly distorted square-planar geometry. The structure forms a one-dimensional chain through weak coordination bonds [Cu...O 3.080 (1, Cu...Cl 3.269 (1 Å] and a three-dimensional network through O—H...O and C—H...O hydrogen bonds.

  4. (3aS,7aS-5-[(S-3,3,3-Trifluoro-2-methoxy-2-phenylpropanoyl]-2,3,4,5,6,7-hexahydro-1H-pyrrolo[3,4-c]pyridin-3(2H-one monohydrate

    Directory of Open Access Journals (Sweden)

    Huichun Zhu

    2010-01-01

    Full Text Available rac-Benzyl 3-oxohexahydro-1H-pyrrolo[3,4-c]pyridine-5(6H-carboxylate was separated by chiral chromatography, and one of the enantiomers ([α]22D = +10° was hydrogenated in the presence of Pd/C in methanol, producing octahydro-3H-pyrrolo[3,4-c]pyridin-3-one. The latter was reacted with (2R-3,3,3-trifluoro-2-methoxy-2-phenylpropanoyl chloride [(R-(−-Mosher acid chloride], giving rise to the title compound, C17H19F3N2O3·H2O. The present structure established the absolute configuration of the pyrrolopiperidine fragment based on the known configuration of the (R-Mosher acid chloride. The piperidine ring has a somewhat distorted chair conformation and is cis-fused with the five-membered envelope-shaped ring; the plane of the exocyclic amide bond is approximately orthogonal to the plane of the phenyl ring, making a dihedral angle of 82.31 (3°. The water molecule acts as an acceptor to the proton of the amino group in an N—H...O interaction, and as a double proton donor in O—H...O hydrogen bonds, generating infinite bands along the a axis.

  5. Methods for the analysis of SO/sub 2/, SO/sub 3/ and H/sub 2/S in flue gas and the calculation of the acid dew point

    Energy Technology Data Exchange (ETDEWEB)

    Albertyn, C.H.

    1986-02-01

    Methods are given for the analysis of SO/sub 2/, SO/sub 3/, and H/sub 2/S in flue gas. Two methods are described for the determination of SO/sub 2/. The method to be used depends on whether or not H/sub 2/S is present in the gas stream. An equation for the calculation of acid dew point is given as well.

  6. Evidence of site-specific fragmentation on thioacetic acid, CH3C(O)SH, irradiated with synchrotron radiation around the S 2p and O 1s regions.

    Science.gov (United States)

    Erben, Mauricio F; Geronés, Mariana; Romano, Rosana M; Della Védova, Carlos O

    2006-01-26

    Site-specific fragmentations following S 2p and O 1s photoexcitation of thioacetic acid, CH3C(O)SH, have been studied by means of synchrotron radiation. Total ion yield (TIY) spectra were measured and multicoincidence techniques, which include photoelectron-photoion coincidence (PEPICO) and photoelectron-photoion-photoion coincidence (PEPIPICO) time-of-flight mass spectrometry, were applied. The equivalent-core approximation was employed in order to estimate ionization transition values, and the observed peaks were tentatively assigned. A site-specific fragmentation is moderately observed by comparing the mass spectra collected at resonant energies around the inner and shallow inner shell S 2p and O 1s ionization edges. Beside H+ ion, the most abundant ions observed at the S 2p edge excitation were CH3CO+, SH+, S+, and CH3+. At the O 1s region the large CH3CO+ fragment was depressed, and small CHx+ (x = 0, 1, 2, 3), S+, and SH+ fragments were dominant. The dissociation dynamic for the main ion-pair production has been discussed. Two- and three-body dissociation channels have been observed in the PEPIPICO spectra, and the dissociation mechanisms were proposed.

  7. Rational design, synthesis, and pharmacological evaluation of 2-azanorbornane-3-exo,5-endo-dicarboxylic acid

    DEFF Research Database (Denmark)

    Bunch, Lennart; Liljefors, Tommy; Greenwood, Jeremy R

    2003-01-01

    conformationally restricted (S)-glutamic acid (Glu) analogue intended as a mimic of the folded Glu conformation. The synthesis of 1 was completed in its racemic form in eight steps from commercially available starting materials. As a key step, the first facially selective hydroboration of a 5-methylidene[2......The design and synthesis of conformationally restricted analogues of alpha-amino acids is an often used strategy in medicinal chemistry research. Here we present the rational design, synthesis, and pharmacological evaluation of 2-azanorbornane-3-exo,5-endo-dicarboxylic acid (1), a novel...... studies on native 2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) (IC(50) > 300 microM, [(3)H]AMPA) or kainic acid (IC(50) > 160 microM, [(3)H]kainic acid) receptors nor in binding studies on the cloned iGluR5,6 subtypes (IC(50) > 300 microM, [(3)H]kainic acid)....

  8. Synthesis and optical resolution of the neurotoxin 2-amino-3-([15N]-methylamino)propanoic acid (BMAA)

    International Nuclear Information System (INIS)

    Yulin Hu; Ziffer, H.

    1990-01-01

    The synthesis of 2-amino-3-([ 15 N]-methylamino)propanoic acid (synonyms, BMAA, β-N-mehylamino-alanine) from α-acetamidoacrylic acid and [ 15 N]-methylamine is described. Enantioselective hydrolysis of the acetamide group, mediated by the enzyme Acylase 1 (EC 3.5.1.14), yielded (R)-BMAA and the (S)-α-acetamido derivative. Acid hydrolysis of the latter compound yielded (S)-BMAA. (author)

  9. Formation of uniform carrot-like Cu31S16-CuInS2 heteronanostructures assisted by citric acid at the oil/aqueous interface.

    Science.gov (United States)

    Li, Yongjie; Tang, Aiwei; Liu, Zhenyang; Peng, Lan; Yuan, Yi; Shi, Xifeng; Yang, Chunhe; Teng, Feng

    2018-01-07

    A simple two-phase strategy was developed to prepare Cu 31 S 16 -CuInS 2 heterostructures (HNS) at the oil/aqueous interface, in which the In(OH) 3 phase was often obtained in the products due to the reaction between indium ions and hydroxyl ions in the aqueous phase. To prevent the formation of the In(OH) 3 phase, citric acid was incorporated into the aqueous phase to assist in the synthesis of uniform carrot-like Cu 31 S 16 -CuInS 2 semiconductor HNS at the oil/aqueous interface for the first time. By manipulating the dosage of citric acid and Cu/In precursor ratios, the morphology of the Cu 31 S 16 -CuInS 2 HNS could be tailored from mushroom to carrot-like, and the presence of citric acid played a critical role in the synthesis of high-quality Cu 31 S 16 -CuInS 2 HNS, which inhibited the formation of the In(OH) 3 phase due to the formation of the indium(iii)-citric acid complex. The formation mechanism was studied by monitoring the morphology and phase evolution of the Cu 31 S 16 -CuInS 2 HNS with reaction time, which revealed that the Cu 31 S 16 seeds were first formed and then the cation-exchange reaction directed the subsequent anisotropic growth of the Cu 31 S 16 -CuInS 2 HNS.

  10. Easy method for the preparation of L (+) 2-amino 3-sulfino propionic acid (cysteine sulfinic acid)

    International Nuclear Information System (INIS)

    Emiliozzi, Romeo; Pichat, Louis

    1960-01-01

    Description of a new method of preparing cystine disulphoxide by oxidising cystine hydrochloride with a mixture of formic acid and hydrogen peroxide. Yield; 85 per cent. The disproportionation of cystine disulphoxide by ammonia gives 2-amino 3-sulfino propionic acid with a yield of 93 per cent. The method had been applied to the preparation of 35 S DL cysteine sulfinic acid. Reprint of a paper published in Bulletin de la Societe Chimique de France, no. 2653, 4. quarter 1959, p. 1887-1888 [fr

  11. (S)-2-Amino-3-(3-hydroxy-7,8-dihydro-6H-cyclohepta[d]isoxazol-4-yl)propionic acid, a potent and selective agonist at the GluR5 subtype of ionotropic glutamate receptors. Synthesis, modeling, and molecular pharmacology

    DEFF Research Database (Denmark)

    Brehm, Lotte; Greenwood, Jeremy R; Hansen, Kasper B

    2003-01-01

    )propionic acid (AMPA) but inactive at NMDA receptors. However, 4-AHCP was found to be much weaker than AMPA as an inhibitor of [(3)H]AMPA binding and to have limited effect in a [(3)H]kainic acid binding assay using rat cortical membranes. To shed light on the mechanism(s) underlying this quite enigmatic......, activated cloned AMPA receptor subunits GluR1o, GluR3o, and GluR4o with EC(50) values in the range 4.5-15 microM and the coexpressed kainate-preferring subunits GluR6 + KA2 (EC(50) = 6.4 microM). Compound 6, but not 7, proved to be a very potent agonist (EC(50) = 0.13 microM) at the kainate-preferring GluR5...... subunit, equipotent with (S)-2-amino-3-(5-tert-butyl-3-hydroxyisothiazol-4-yl)propionic acid [(S)-Thio-ATPA, 4] and almost 4 times more potent than (S)-2-amino-3-(5-tert-butyl-3-hydroxyisoxazol-4-yl)propionic acid [(S)-ATPA, 3]. Compound 6 thus represents a new structural class of GluR5 agonists...

  12. Synthesis of specifically 2H-labeled reserpines, 3,4,5-trimethoxybenzoic acids, and syringic acid

    International Nuclear Information System (INIS)

    Roth, R.W.; Fischer, D.L.; Pachta, J.M.; Althaus, J.F.

    1982-01-01

    3,4,5-Trimethoxy- 2 H 9 -, 4-methoxy-3,5-dimethoxy- 2 H 6 , and 4-hydroxyl-3,5-dimethoxy- 2 H 6 -benzoic acids were prepared from n-propyl 3,4,5-trihydroxybenzoate (n-propyl gallate) by means of appropriate alkylation-hydrolysis sequences employing iodomethane- 2 H 3 or dimethyl- 2 H 6 -sulfate as the deuterium source. 4-Methoxy- 2 H 3 -3,5-dimethoxybenzoic acid was similarly prepared from ethyl 4-hydroxy-3,5-dimethoxybenzoate. The labeled trimethoxybenzoic acids were converted to the corresponding 2 H-labeled reserpines by condensation of the acid chlorides with methyl reserpate in pyridine according to the classical procedure. The labeled reserpine analog methyl 18-0-(4-hydroxy-3,5-dimethoxy- 2 H 6 )benzoyl reserpate was likewise prepared from 4-hydroxy-3,5-dimethoxy- 2 H 6 -benzoic acid via the intermediate methyl 18-0-(4-ethoxycarbonyloxy-3,5-dimethoxy- 2 H 6 -benzoyl)reserpate (syrosingopine- 2 H 6 ). The isotopic purity of each compound exceeded 99 atom percent 2 H. (author)

  13. Enhanced visible-light photocatalytic decomposition of 2,4-dichlorophenoxyacetic acid over ZnIn{sub 2}S{sub 4}/g-C{sub 3}N{sub 4} photocatalyst

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Pengxiang; Yao, Jinhua [Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, Engineering Research Center for Chemical Pollution Control, Ministry of Education, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Chen, Huan, E-mail: hchen404@njust.edu.cn [Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, Engineering Research Center for Chemical Pollution Control, Ministry of Education, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Jiang, Fang, E-mail: fjiang@njust.edu.cn [Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, Engineering Research Center for Chemical Pollution Control, Ministry of Education, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Xie, Xianchuan [State Key Laboratory of Pollution Control and Resource Reuse, Center for Hydrosciences Research, School of the Environment, Nanjing University, Nanjing 210094 (China)

    2016-11-05

    Highlights: • A novel flower-on-sheet ZnIn{sub 2}S{sub 4}/g-C{sub 3}N{sub 4} nanocomposite was synthesized. • ZnIn{sub 2}S{sub 4}/g-C{sub 3}N{sub 4} showed high visible light catalytic activity for 2,4-D degradation. • The photocatalytic degradation pathway of 2,4-D was investigated. - Abstract: ZnIn{sub 2}S{sub 4}/g-C{sub 3}N{sub 4} heterojunction photocatalyst was successfully synthesized via a simple hydrothermal method and applied to visible-light photocatalytic decomposition of 2,4-dichlorophenoxyacetic acid (2,4-D) from aqueous phase. The flower-like ZnIn{sub 2}S{sub 4} particles were dispersed on the surface of g-C{sub 3}N{sub 4} nanosheets in the ZnIn{sub 2}S{sub 4}/g-C{sub 3}N{sub 4} composite. The composite showed higher separation rate of electron-hole pairs as compared to ZnIn{sub 2}S{sub 4} and g-C{sub 3}N{sub 4}. Consequently, the ZnIn{sub 2}S{sub 4}/g-C{sub 3}N{sub 4} composite exhibited enhanced visible light photocatalytic decomposition efficiency of 2,4-D, within 20% ZnIn{sub 2}S{sub 4}/g-C{sub 3}N{sub 4} composite owning the highest photocatalytic efficiency and initial rate. The initial rates of 2,4-D degradation on g-C{sub 3}N{sub 4}, ZnIn{sub 2}S{sub 4}, and 20% ZnIn{sub 2}S{sub 4}/g-C{sub 3}N{sub 4} were 1.23, 0.57 and 3.69 mmol/(g{sub cat} h), respectively. The h{sup +} and O{sub 2}{sup ·−} were found to be the dominant active species for 2,4-D decomposition. The photocatalytic degradation pathways of 2,4-D by ZnIn{sub 2}S{sub 4}/g-C{sub 3}N{sub 4} under visible light irradiation were explored. The ZnIn{sub 2}S{sub 4}/g-C{sub 3}N{sub 4} composite displayed high photostability in recycling tests, reflecting its promising potential as an effective visible light photocatalyst for 2,4-D treatment.

  14. Microtropins A-I: 6'-O-(2S,3″R)-2″-ethyl-2″,3″-dihydroxybutyrates of aliphatic alcohol β-D-glucopyranosides from the branches of Microtropis japonica.

    Science.gov (United States)

    Uemura, Yuka; Sugimoto, Sachiko; Matsunami, Katsuyoshi; Otsuka, Hideaki; Takeda, Yoshio; Kawahata, Masatoshi; Yamaguchi, Kentaro

    2013-03-01

    From the branches of Microtropis japonica (Celastraceae), nine aliphatic glucosides, named microtropins A-I, were isolated. The 6-position of glucose was esterified with (2S,3R)-2-ethyl-2,3-dihydroxybutyric acid. Microtropins A-D contained a rare natured product nitrile functional group in their aglycones. The absolute structures of the (2S,3R)-2-ethyl-2,3-dihydroxybutyric acid moiety and aglycone of microtropin A were determined by an X-ray crystallographic method. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Multidrug Resistance Proteins and the Renal Elimination of Inorganic Mercury Mediated by 2,3-Dimercaptopropane-1-Sulfonic Acid and Meso-2,3-dimercaptosuccinic Acid

    Science.gov (United States)

    Bridges, Christy C.; Joshee, Lucy; Zalups, Rudolfs K.

    2008-01-01

    Current therapies for inorganic mercury (Hg2+) intoxication include administration of a metal chelator, either 2,3-dimercaptopropane-1-sulfonic acid (DMPS) or meso-2,3-dimercaptosuccinic acid (DMSA). After exposure to either chelator, Hg2+ is rapidly eliminated from the kidneys and excreted in the urine, presumably as an S-conjugate of DMPS or DMSA. The multidrug resistance protein 2 (Mrp2) has been implicated in this process. We hypothesize that Mrp2 mediates the secretion of DMPS- or DMSA-S-conjugates of Hg2+ from proximal tubular cells. To test this hypothesis, the disposition of Hg2+ was examined in control and Mrp2-deficient TR− rats. Rats were injected i.v. with 0.5 μmol/kg HgCl2 containing 203Hg2+. Twenty-four and 28 h later, rats were injected with saline, DMPS, or DMSA. Tissues were harvested 48 h after HgCl2 exposure. The renal and hepatic burden of Hg2+ in the saline-injected TR− rats was greater than that of controls. In contrast, the amount of Hg2+ excreted in urine and feces of TR− rats was less than that of controls. DMPS, but not DMSA, significantly reduced the renal and hepatic content of Hg2+ in both groups of rats, with the greatest reduction in controls. A significant increase in urinary and fecal excretion of Hg2+, which was greater in the controls, was also observed following DMPS treatment. Experiments utilizing inside-out membrane vesicles expressing MRP2 support these observations by demonstrating that DMPS- and DMSA-S-conjugates of Hg2+ are transportable substrates of MRP2. Collectively, these data support a role for Mrp2 in the DMPS- and DMSA-mediated elimination of Hg2+ from the kidney. PMID:17940195

  16. Properties of TiO2 prepared by acid treatment of BaTiO3

    International Nuclear Information System (INIS)

    Okada, Kiyoshi; Yanagisawa, Tomoki; Kameshima, Yoshikazu; Nakajima, Akira

    2007-01-01

    TiO 3 powders were prepared by acid treatment of BaTiO 3 and their properties were investigated. The BaTiO 3 powder was subjected to HNO 3 in concentrations ranging from 10 -3 to 8 M at 90 deg. C for 0.5-6 h. Dissolution of BaTiO 3 and precipitation of TiO 2 occurred at acid concentrations of 2-5 M. BaTiO 3 dissolves completely to form a clear solution at reaction times of 0.5-1 h, but a rutile precipitate is formed after 2 h of acid treatment. By contrast, anatase is precipitated by adjusting the pH of the clear solution to 2-3 using NaOH or NH 4 OH solution. The rutile crystals were small and rod-shaped, consisting of many small coherent domains connected by grain boundaries with small inclination angles and edge dislocations, giving them a high specific surface area (S BET ). With increasing HNO 3 concentration, the S BET value increased from 100 to 170 m 2 /g while the crystallite size decreased from 25 to 11 nm. The anatase crystals obtained here were very small equi-axial particles with a smaller crystallite size than the rutile and S BET values of about 270 m 2 /g (higher than the rutile samples). The photocatalytic activity of these TiO 2 was determined from the decomposition rate of Methylene Blue under ultraviolet irradiation. Higher decomposition rates were obtained with larger crystallite sizes resulting from heat treatment. The maximum decomposition rates were obtained in samples heated at 500-600 deg. C. The photocatalytic activity of the TiO 2 was found to depend more strongly on the sample crystallite size than on S BET

  17. Crystal structure of rac-3-[2,3-bis(phenylsulfanyl-3H-indol-3-yl]propanoic acid

    Directory of Open Access Journals (Sweden)

    Wayland E. Noland

    2015-11-01

    Full Text Available The title compound, C23H19NO2S2, was obtained as an unexpected regioisomer from an attempted synthesis of an intermediate for a substituent-effect study on ergot alkaloids. This is the first report of a 1H-indole monothioating at the 2- and 3-positions to give a 3H-indole. In the crystal, the acid H atom is twisted roughly 180° from the typical carboxy conformation and forms centrosymmetric O—H...N hydrogen-bonded dimers with the indole N atom of an inversion-related molecule. Together with a weak C—H...O hydrogen bond involving the carbonyl O atom, chains are formed along [100].

  18. Apports spontanés en acides gras oméga 3 chez des diabétiques de type 2 tunisiens

    Directory of Open Access Journals (Sweden)

    Jamoussi Henda

    2014-09-01

    Full Text Available Il est admis à l’unanimité que les acides gras oméga 3 ont de multiples bénéfices pour la santé et plus précisément des effets protecteurs contre les maladies cardiovasculaires et neurodégénératives. L’objectif de ce travail était d’estimer les apports spontanés en acides alphalinolénique (ALA, docosahexaénoïque (DHA, éicosapentaénoïque (EPA et linoléique (LA. Cette étude d’observation a été réalisée auprès de 42 diabétiques de type 2 (21 hommes et 21 femmes âgés de 30 à 75 ans. L’estimation des apports en acides gras a été réalisée en utilisant la méthode d’enregistrement sur sept jours. Les résultats ont montré que l’apport moyen en ALA était de 0,99 ± 0,40 g/j soit 0,42 ± 0,13 % de l’apport énergétique total (AET. Aucun de nos patients n’avait un apport suffisant en ALA. Les apports quotidiens moyens en DHA et en EPA étaient respectivement de 90,0 ± 85 mg/j et de 83,5 ± 80 mg/j. Quant à la contribution des aliments aux apports en EPA et en DHA, les poissons et les fruits de mer représentaient la part la plus importante (57 % de ces deux acides gras. Nos résultats appellent à renforcer l’éducation nutritionnelle des diabétiques afin d’augmenter les apports en acides gras oméga 3 et d’assurer un rapport LA/ALA optimal qui contribuerait à la prévention des maladies cardiovasculaires.

  19. Copper diffusion in In2S3 and charge separation at In2S3/CuSCN and TiO2/In2S3 interfaces

    International Nuclear Information System (INIS)

    Juma, Albert Owino

    2013-01-01

    The concept of inorganic nanostructured solar cells consists of a very thin absorber layer sandwiched between highly structured electron and hole conductors. When a TiO 2 /In 2 S 3 /CuSCN nanocomposite heterostructure is illuminated with light, photo-generated electrons in In 2 S 3 can be injected into the conduction band of TiO 2 and holes into the valence band of CuSCN. Charge transfer at the interfaces is limited by the deposition parameters, band alignment and diffusion of Cu from CuSCN into In 2 S 3 , which was the focus of this work. TiO 2 nanoparticles were screen printed onto SnO 2 :F (FTO)-coated glass substrates to give a layer of nanoporous (np) TiO 2 . In 2 S 3 layers were deposited by thermal evaporation or ion layer gas reaction (ILGAR) methods producing Cl-free (In(acac) 3 precursor) and Cl-containing (InCl 3 precursor) layers. A spray-spin method was developed for deposition of CuSCN onto In 2 S 3 . Diffusion of Cu into In 2 S 3 layers was investigated by Rutherford backscattering spectrometry (RBS) while charge transport mechanisms were studied with surface photovoltage (SPV) technique in the fixed capacitor configuration. The activation energy (Ea) for Cu diffusion in thermally evaporated and Cl-free ILGAR In 2 S 3 layers was 0.30 and 0.24 eV, respectively but increased to between 0.72 and 0.78 eV for Cl-containing In 2 S 3 with residual Cl concentrations of 7.8 - 13.8 at.%. The diffusion prefactor (D 0 ) was six orders of magnitude higher for Cl-containing compared to Cl-free layers. The relationship between E a and D 0 was described by the Meyer-Neldel rule with a Meyer-Neldel energy of 40 meV. The presence of Cl has no significant influence on the structural properties of In 2 S 3 but resulted in a modified diffusion mechanism for Cu diffusion. The photovoltage of In 2 S 3 /CuSCN samples decreased after annealing for longer than 2 min at 200 C. A defect band was formed near the interface where holes accumulated and electrons tunneled through

  20. Resolution, configurational assignment, and enantiopharmacology at glutamate receptors of 2-amino-3-(3-carboxy-5-methyl-4-isoxazolyl)propionic acid (ACPA) and demethyl-ACPA

    DEFF Research Database (Denmark)

    Johansen, T N; Stensbøl, T B; Nielsen, B

    2001-01-01

    We have previously described (RS)-2-amino-3-(3-carboxy-5-methyl-4-isoxazolyl)propionic acid (ACPA) as a potent agonist at the (RS)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) receptor subtype of (S)-glutamic acid (Glu) receptors. We now report the chromatographic resolution...... of ACPA and (RS)-2-amino-3-(3-carboxy-4-isoxazolyl)propionic acid (demethyl-ACPA) using a Sumichiral OA-5000 column. The configuration of the enantiomers of both compounds have been assigned based on X-ray crystallographic analyses, supported by circular dichroism spectra and elution orders on chiral HPLC...... columns. Furthermore, the enantiopharmacology of ACPA and demethyl-ACPA was investigated using radioligand binding and cortical wedge electrophysiological assay systems and cloned metabotropic Glu receptors. (S)-ACPA showed high affinity in AMPA binding (IC(50) = 0.025 microM), low affinity in kainic acid...

  1. Mechanism of Inactivation of γ-Aminobutyric Acid Aminotransferase by (1 S ,3 S )-3-Amino-4-difluoromethylene-1-cyclopentanoic Acid (CPP-115)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyunbeom [Department; Doud, Emma H. [Department; Department; Wu, Rui [Department; Sanishvili, Ruslan [X-ray; Juncosa, Jose I. [Department; Liu, Dali [Department; Kelleher, Neil L. [Department; Department; Silverman, Richard B. [Department; Department

    2015-02-10

    gamma-Aminobutyric acid aminotransferase (GABA-AT) is a pyridoxal 5'-phosphate (PLP)-dependent enzyme that degrades GABA, the principal inhibitory neurotransmitter in mammalian cells. When the concentration of GABA falls below a threshold level, convulsions can occur. Inhibition of GABA-AT raises GABA levels in the brain, which can terminate seizures as well as have potential therapeutic applications in treating other neurological disorders, including drug addiction. Among the analogues that we previously developed, (1S,3S)-3-amino-4-difluoromethylene-1-cyclopentanoic acid (CPP-115) showed 187 times greater potency than that of vigabatrin, a known inactivator of GABA-AT and approved drug (Sabril) for the treatment of infantile spasms and refractory adult epilepsy. Recently, CPP-115 was shown to have no adverse effects in a Phase I clinical trial. Here we report a novel inactivation mechanism for CPP-115, a mechanism-based inactivator that undergoes GABA-AT-catalyzed hydrolysis of the difluoromethylene group to a carboxylic acid with concomitant loss of two fluoride ions and coenzyme conversion to pyridoxamine 5'-phosphate (PMP). The partition ratio for CPP-115 with GABA-AT is about 2000, releasing cyclopentanone-2,4-dicarboxylate (22) and two other precursors of this compound (20 and 21). Time-dependent inactivation occurs by a conformational change induced by the formation of the aldimine of 4-aminocyclopentane-1,3-dicarboxylic acid and PMP (20), which disrupts an electrostatic interaction between Glu270 and Arg445 to form an electrostatic interaction between Arg445 and the newly formed carboxylate produced by hydrolysis of the difluoromethylene group in CPP-115, resulting in a noncovalent, tightly bound complex. This represents a novel mechanism for inactivation of GABA-AT and a new approach for the design of mechanism-based inactivators in general.

  2. Anticonvulsant activity of a mGlu(4alpha) receptor selective agonist, (1S,3R,4S)-1-aminocyclopentane-1,2,4-tricarboxylic acid.

    Science.gov (United States)

    Chapman, A G; Talebi, A; Yip, P K; Meldrum, B S

    2001-07-20

    The metabotropic Group III agonist, (1S,3R,4S)-1-aminocyclopentane-1,2,4-tricarboxylic acid (ACPT-1), selective for the mGlu(4alpha) receptor, suppresses sound-induced seizures in DBA/2 mice following its intracerebroventricular (i.c.v.) administration (ED(50) 5.6 [2.9-10.7], nmol i.c.v., 15 min, clonic phase) and in genetically epilepsy-prone (GEP) rats following focal administration into the inferior colliculus (ED(50) 0.08 [0.01-0.50], nmol, 60 min, clonic phase). ACPT-1 also protects against clonic seizures induced in DBA/2 mice by the Group I agonist, (RS)-3,5-dihydroxyphenylglycine (3,5-DHPG) (ED(50) 0.60 [0.29-1.2], nmol i.c.v.) and by the Group III antagonist, (RS)-alpha-methylserine-O-phosphate (MSOP) (ED(50) 49.3 [37.9-64.1], nmol i.c.v.). Another Group III agonist, (RS)-4-phosphonophenyl-glycine (PPG), preferentially activating the mGlu(8) receptor, previously shown to protect against sound-induced seizures in DBA/2 mice and GEP rats, also protects against seizures induced in DBA/2 by 3,5-DHPG (ED(50) 3.7 [2.4-5.7], nmol i.c.v.) and by the Group III antagonist, MSOP (ED(50) 40.2 [21.0-77.0], nmol i.c.v.). At very high doses (500 nmol i.c.v. and above), Group III antagonists have pro-convulsant and convulsant activity. The anticonvulsant protection against sound-induced seizures in DBA/2 mice provided by a fully protective dose (20 nmol, i.c.v.) of the mGlu(4) receptor agonist ACPT-1, is partially reversed by the co-administration of the Group III antagonists, MSOP, (RS)-alpha-methyl-4-phosphonophenylglycine (MPPG) or (S)-2-amino-2-methyl-4-phosphonobutanoic acid (MAP4), in the 20-50 nmol dose range. At doses of 50-200 nmol, MPPG and MAP4 cause further reversal of the ACPT-1 anticonvulsant protection, while the MSOP effect on ACPT-1 protection is abolished at higher doses. In contrast, the anticonvulsant protection against sound-induced seizures in DBA/2 mice provided by a fully protective dose (20 nmol, i.c.v.) of the mGlu(8) receptor agonist PPG, is not

  3. Electron Excitation Cross Sections for the S II Transitions: 3s(exp 2)3p(exp 3) 4S(exp o) approaches 3s(exp 2)3p(exp 3) 2D(exp o), 2P(exp o), and 3s3p(exp 4) 4P

    Science.gov (United States)

    Liao, C.; Chutjian, A.; Hitz, D.; Tayal, S. S.

    1997-01-01

    Experimental and theoretical collisional excitation cross sections are reported for the transitions 3s(exp 2)3p(exp 3)4S(exp o) approaches 3s(exp 2)3p(exp 3) 2D(exp o), 2P(exp o), and 3s3P(exp 4) 4P in S II. The transition wavelengths (energies) are 6716 A (1.85 eV), 4069 A (3.05 eV), and 1256 A (9.87 eV), respectively. In the experiments, use is made of the energy-loss merged-beams method. The metastable fraction of the S II beam was assessed and minimized. The contribution of elastically scattered electrons was reduced by the use of a lowered solenoidal magnetic field and a modulated radio-frequency voltage on the analyzing plates and by retarding grids to reject the elastically scattered electrons with larger Larmor radii. For each transition, comparisons are made among experiments, the new 19 state R-matrix calculation, and three other close-coupling calculations.

  4. [Enhanced electro-chemical oxidation of Acid Red 3R solution with phosphotungstic acid supported on gamma-Al2O3].

    Science.gov (United States)

    Yue, Lin; Wang, Kai-Hong; Guo, Jian-Bo; Yang, Jing-Liang; Liu, Bao-You; Lian, Jing; Wang, Tao

    2013-03-01

    Supported phosphotungstic acid catalysts on gamma-Al2O3 (HPW/gamma-Al2O3) were prepared by solution impregnation and characterized by FTIR, XRD, TG-DTA and SEM. The heteropolyanion shows a Keggin structure. Electro-chemical oxidation of Acid Red 3R was investigated in the presence of HPW supported on gamma-Al2O3 as packing materials in the reactor. The results show that HPW/gamma-Al2O3 has a good catalytic activity for decolorization of Acid Red 3R. When HPW loading was 4.6%, pH value of Acid Red 3R was 3, the voltage was 25.0 V, air-flow was 0.04 m3 x h(-1), and electrode span was 3.0 cm, the decolorization efficiency of Acid Red 3R can reach 97.6%. The removal rate of color had still about 80% in this electro-chemical oxidation system, after HPW/gamma-Al2O3 was used for 10 times, but active component loss existed. The interim product was analyzed by means of Vis-UV absorption spectrum. It shows that the conjugated structure of dye is destroyed primarily.

  5. Enhanced photovoltaic performance of Sb2S3-sensitized solar cells through surface treatments

    Science.gov (United States)

    Ye, Qing; Xu, Yafeng; Chen, Wenyong; Yang, Shangfeng; Zhu, Jun; Weng, Jian

    2018-05-01

    Efficient antimony sulfide (Sb2S3)-sensitized solar cells were obtained by a sequential treatment with thioacetamide (TA) and 1-decylphosphonic acid (DPA). Compared with the untreated Sb2S3-sensitized solar cells, the power conversion efficiency of the treated Sb2S3 solar cells was improved by 1.80% to 3.23%. The TA treatment improved the Sb2S3 films by reducing impurities and decreasing the film's surface defects, which inhibited the emergence of recombination centers. The DPA treatment reduced the recombination between hole transport materials (HTMs) and the Sb2S3. Therefore, we have presented an efficient strategy to improve the performance of Sb2S3-sensitized solar cells.

  6. Electrolytic nature of aqueous sulfuric acid. 2. Acidity.

    Science.gov (United States)

    Fraenkel, Dan

    2012-09-27

    In part 1 of this study, I reported that the Debye-Hückel limiting law and the smaller-ion shell (SiS) model of strong electrolyte solutions fit nicely with the experimental mean ionic activity coefficient (γ(±)) of aqueous sulfuric acid as a function of concentration and of temperature when the acid is assumed to be a strong 1-3 electrolyte. Here, I report that the SiS-derived activity coefficient of H(+), γ(H(+)), of the 1-3 acid is comparable to that of aqueous HCl. This agrees with titration curves showing, as well-known, that sulfuric acid in water is parallel in strength to aqueous HCl. The calculated pH is in good accord with the Hammett acidity function, H(0), of aqueous sulfuric acid at low concentration, and differences between the two functions at high concentration are discussed and explained. This pH-H(0) relation is consistent with the literature showing that the H(0) of sulfuric acid (in the 1-9 M range) is similar to those of HCl and the other strong mineral monoprotic acids. The titration of aqueous sulfuric acid with NaOH does not agree with the known second dissociation constant of 0.010 23; rather, the constant is found to be ~0.32 and the acid behaves upon neutralization as a strong diprotic acid practically dissociating in one step. A plausible reaction pathway is offered to explain how the acid may transform, upon base neutralization, from a dissociated H(4)SO(5) (as 3H(+) and HSO(5)(3-)) to a dissociated H(2)SO(4) even though the equilibrium constant of the reaction H(+) + HSO(5)(3-) ↔ SO(4)(2-) + H(2)O, at 25 °C, is 10(-37) (part 1).

  7. New fluorescent bile acids: synthesis, chemical characterization, and disastereoselective uptake by Caco-2 cells of 3-deoxy 3-NBD-amino deoxycholic and ursodeoxycholic acid.

    Science.gov (United States)

    Májer, Ferenc; Salomon, Johanna J; Sharma, Ruchika; Etzbach, Simona V; Najib, Mohd Nadzri Mohd; Keaveny, Ray; Long, Aideen; Wang, Jun; Ehrhardt, Carsten; Gilmer, John F

    2012-03-01

    Deoxycholic acid (DCA), a secondary bile acid (BA), and ursodeoxycholic acid (UDCA), a tertiary BA, cause opposing effects in vivo and in cell suspensions. Fluorescent analogues of DCA and UDCA could help investigate important questions about their cellular interactions and distribution. We have prepared a set of isomeric 3α- and 3β-amino analogues of UDCA and DCA and derivatised these with the discrete fluorophore, 4-nitrobenzo-2-oxa-1,3-diazol (NBD), forming the corresponding four fluorescent adducts. These absorb in the range 465-470 nm and fluoresce at approx. 535 nm. In order to determine the ability of the new fluorescent bile acids to mimic the parents, their uptake was studied using monolayers of Caco-2 cells, which are known to express multiple proteins of the organic anion-transporting peptide (OATP) subfamily of transporters. Cellular uptake was monitored over time at 4 and 37°C to distinguish between passive and active transport. All four BA analogues were taken up but in a strikingly stereo- and structure-specific manner, suggesting highly discriminatory interactions with transporter protein(s). The α-analogues of DCA and to a lesser extent UDCA were actively transported, whereas the β-analogues were not. The active transport process was saturable, with Michaelis-Menten constants for 3α-NBD DCA (5) being K(m)=42.27±12.98 μM and V(max)=2.8 ± 0.4 nmol/(mg protein*min) and for 3α-NBD UDCA (3) K(m)=28.20 ± 7.45 μM and V(max)=1.8 ± 0.2 nmol/(mg protein*min). These fluorescent bile acids are promising agents for investigating questions of bile acid biology and for detection of bile acids and related organic anion transport processes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. 40 CFR 721.3031 - Boric acid (H3BO3), zinc salt (2=3).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Boric acid (H3BO3), zinc salt (2=3). 721.3031 Section 721.3031 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.3031 Boric acid (H3BO...

  9. Metabolic solutions to the biosynthesis of some diaminomonocarboxylic acids in nature: Formation in cyanobacteria of the neurotoxins 3-N-methyl-2,3-diaminopropanoic acid (BMAA) and 2,4-diaminobutanoic acid (2,4-DAB).

    Science.gov (United States)

    Nunn, Peter B; Codd, Geoffrey A

    2017-12-01

    The non-encoded diaminomonocarboxylic acids, 3-N-methyl-2,3-diaminopropanoic acid (syn: α-amino-β-methylaminopropionic acid, MeDAP; β-N-methylaminoalanine, BMAA) and 2,4-diaminobutanoic acid (2,4-DAB), are distributed widely in cyanobacterial species in free and bound forms. Both amino acids are neurotoxic in whole animal and cell-based bioassays. The biosynthetic pathway to 2,4-DAB is well documented in bacteria and in one higher plant species, but has not been confirmed in cyanobacteria. The biosynthetic pathway to BMAA is unknown. This review considers possible metabolic routes, by analogy with reactions used in other species, by which these amino acids might be biosynthesised by cyanobacteria, which are a widespread potential environmental source of these neurotoxins. Where possible, the gene expression that might be implicated in these biosyntheses is discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Figure S1 Figure S2

    Indian Academy of Sciences (India)

    WINTEC

    6.8. 7.0. 7.2. 7.4. 7.6. 7.8. 8.0. 8.2. 8.4. 8.6. 8.8 ppm. 0.0. 1.8. 9.7. 5.4. 6.9. 8.1. 9.0. 10.8. 3.2. 10.3. Figure S3. NMR titration of DAN-Ia acid with NDI at 30% MeOH in CDCl3. The numbers represent the mole ratios of the DAN-acid to the repeat unit.

  11. 1,3,5-Triazine-2,4,6-triyltrisulfamic acid (TTSA)

    Indian Academy of Sciences (India)

    Melamine reacted with chlorosufonic acid (ClSO3H) to form a new sulfamic-type acid, 1,3,5-triazine-2,4,6-triyltrisulfamic acid (TTSA). Both nitrosation of secondary amines and oxidation of urazoles were accomplished by using TTSA/NaNO2 system under mild and heterogeneous conditions with good to excellent yields.

  12. H2S and volatile fatty acids elimination by biofiltration: clean-up process for biogas potential use.

    Science.gov (United States)

    Ramírez-Sáenz, D; Zarate-Segura, P B; Guerrero-Barajas, C; García-Peña, E I

    2009-04-30

    In the present work, the main objective was to evaluate a biofiltration system for removing hydrogen sulfide (H(2)S) and volatile fatty acids (VFAs) contained in a gaseous stream from an anaerobic digestor (AD). The elimination of these compounds allowed the potential use of biogas while maintaining the methane (CH(4)) content throughout the process. The biodegradation of H(2)S was determined in the lava rock biofilter under two different empty bed residence times (EBRT). Inlet loadings lower than 200 g/m(3)h at an EBRT of 81 s yielded a complete removal, attaining an elimination capacity (EC) of 142 g/m(3)h, whereas at an EBRT of 31 s, a critical EC of 200 g/m(3)h was reached and the EC obtained exhibited a maximum value of 232 g/m(3)h. For 1500 ppmv of H(2)S, 99% removal was maintained during 90 days and complete biodegradation of VFAs was observed. A recovery of 60% as sulfate was obtained due to the constant excess of O(2) concentration in the system. Acetic and propionic acids as a sole source of carbon were also evaluated in the bioreactor at different inlet loadings (0-120 g/m(3)h) obtaining a complete removal (99%) for both. Microcosms biodegradation experiments conducted with VFAs demonstrated that acetic acid provided the highest biodegradation rate.

  13. Novel 2D or 3D alkaline-earth metal sulfonate-phosphonates based on [O 3S-C 2H 4-PO 3H] 2- ligand

    Science.gov (United States)

    Du, Zi-Yi; Wen, He-Rui; Xie, Yong-Rong

    2008-11-01

    Three novel alkaline-earth metal sulfonate-phosphonates based on [O 3S-C 2H 4-PO 3H] 2- ligand, namely, [Ca(O 3SC 2H 4PO 3H)(H 2O) 2] ( 1), [Sr(O 3SC 2H 4PO 3H)] ( 2) and [Ba 2(O 3SC 2H 4PO 3H) 2] ( 3), have been synthesized by hydrothermal reactions. They represent the first structurally characterized alkaline-earth metal complexes of phosphonic acid attached with a sulfonate group. The structure of compound 1 features a 2D layer based on 1D chains of [Ca 2(PO 3) 2] bridged by -CH 2-CH 2-SO 3- groups. Compounds 2 and 3 show pillar-layer architecture based on two different inorganic layers linked by -CH 2-CH 2- groups. The inorganic layer in compound 2 features a 1D chain of edge-sharing SrO 8 polyhedra whereas that in compound 3 features an edge-sharing Ba 2O 14 di-polyhedral unit which is further corner-shared with four neighboring ones. The [O 3S-C 2H 4-PO 3H] 2- ligand shows diverse coordination modes in the three alkaline-earth metal sulfonate-phosphonates.

  14. Incorporation of 2(S)-methylbutanoic acid-1-14C into the structure of mevinolin

    International Nuclear Information System (INIS)

    Willard, A.K.; Smith, R.L.

    1982-01-01

    A route to mevinolin approximately equal to (1) bearing (S)-2-methylbutanoic acid -1- 14 C as the ester side chain has been developed. The structure of mevinolin approximately equal to (1) was degraded and selectively protected to provide the alcohol approximately equal to 3 in three steps. Incorporation of 14 C was accomplished by acylation of alcohol approximately equal to 3 with (R,S)-2-methylbutyryl chloride-1- 14 C. Cleavage of the silyl ether protecting group in the resulting mixture of esters approximately equal to 4 provided the two diastereoisomers approximately equal to 5 and approximately equal to 6 which were separated by reverse-phase liquid chromatography. Mevinolin - 14 C approximately equal to (5) was also converted to the ammonium salt approximately equal to 7 of the corresponding dihydroxy acid. (author)

  15. Roles of phospholipase A2 isoforms in swelling- and melittin-induced arachidonic acid release and taurine efflux in NIH3T3 fibroblasts

    DEFF Research Database (Denmark)

    Pedersen, Stine Helene Falsig; Poulsen, Kristian Arild; Lambert, Ian H.

    2006-01-01

    Osmotic swelling of NIH3T3 mouse fibroblasts activates a bromoenol lactone (BEL)-sensitive taurine efflux, pointing to the involvement of a Ca2+-independent phospholipase A2 (iPLA2) (Lambert IH. J Membr Biol 192: 19-32, 2003). We report that taurine efflux from NIH3T3 cells was not only increased...... by cell swelling but also decreased by cell shrinkage. Arachidonic acid release to the cell exterior was similarly decreased by shrinkage yet not detectably increased by swelling. NIH3T3 cells were found to express cytosolic calcium-dependent cPLA2-IVA, cPLA2-IVB, cPLA2-IVC, iPLA2-VIA, iPLA2-VIB......, and secretory sPLA2-V. Arachidonic acid release from swollen cells was partially inhibited by BEL and by the sPLA2-inhibitor manoalide. Cell swelling elicited BEL-sensitive arachidonic acid release from the nucleus, to which iPLA2-VIA localized. Exposure to the bee venom peptide melittin, to increase PLA2...

  16. IR, FT-ICR-MS studies on (1'S, 6'S)-1-cyclopropyl-7-(2,8-diazabicyclo[4.3.0] non-8-yl)-6-fluoro-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid hydrochloride salt.

    Science.gov (United States)

    Lin, Zhiwei

    2014-01-01

    The infrared spectra of (1'S, 6'S)-1-cyclopropyl-7-(2,8-diazabicyclo[4.3.0] non-8-yl)-6-fluoro-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid hydrochloride salt (CLF-HCl) were studied and compared with free base. Their fragmentation pathways were investigated using tandem mass spectrometric (MS/MS) techniques on Fourier-transform ion cyclotron resonance spectrum, and many characteristic fragment ions were found. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Pharmacokinetic analysis of trichloroethylene metabolism in male B6C3F1 mice: Formation and disposition of trichloroacetic acid, dichloroacetic acid, S-(1,2-dichlorovinyl)glutathione and S-(1,2-dichlorovinyl)-L-cysteine

    Science.gov (United States)

    Kim, Sungkyoon; Kim, David; Pollack, Gary M.; Collins, Leonard B.; Rusyn, Ivan

    2009-01-01

    Trichloroethylene (TCE) is a well-known carcinogen in rodents and concerns exist regarding its potential carcinogenicity in humans. Oxidative metabolites of TCE, such as dichloroacetic acid (DCA) and trichloroacetic acid (TCA), are thought to be hepatotoxic and carcinogenic in mice. The reactive products of glutathione conjugation, such as S-(1,2-dichlorovinyl)-L-cysteine (DCVC), and S-(1,2-dichlorovinyl) glutathione (DCVG), are associated with renal toxicity in rats. Recently, we developed a new analytical method for simultaneous assessment of these TCE metabolites in small-volume biological samples. Since important gaps remain in our understanding of the pharmacokinetics of TCE and its metabolites, we studied a time-course of DCA, TCA, DCVG and DCVG formation and elimination after a single oral dose of 2100 mg/kg TCE in male B6C3F1 mice. Based on systemic concentration-time data, we constructed multi-compartment models to explore the kinetic properties of the formation and disposition of TCE metabolites, as well as the source of DCA formation. We conclude that TCE-oxide is the most likely source of DCA. According to the best-fit model, bioavailability of oral TCE was ~74%, and the half-life and clearance of each metabolite in the mouse were as follows: DCA: 0.6 hr, 0.081 ml/hr; TCA: 12 hr, 3.80 ml/hr; DCVG: 1.4 hr, 16.8 ml/hr; DCVC: 1.2 hr, 176 ml/hr. In B6C3F1 mice, oxidative metabolites are formed in much greater quantities (~3600 fold difference) than glutathione-conjugative metabolites. In addition, DCA is produced to a very limited extent relative to TCA, while most of DCVG is converted into DCVC. These pharmacokinetic studies provide insight into the kinetic properties of four key biomarkers of TCE toxicity in the mouse, representing novel information that can be used in risk assessment. PMID:19409406

  18. Pharmacokinetic analysis of trichloroethylene metabolism in male B6C3F1 mice: Formation and disposition of trichloroacetic acid, dichloroacetic acid, S-(1,2-dichlorovinyl)glutathione and S-(1,2-dichlorovinyl)-L-cysteine

    International Nuclear Information System (INIS)

    Kim, Sungkyoon; Kim, David; Pollack, Gary M.; Collins, Leonard B.; Rusyn, Ivan

    2009-01-01

    Trichloroethylene (TCE) is a well-known carcinogen in rodents and concerns exist regarding its potential carcinogenicity in humans. Oxidative metabolites of TCE, such as dichloroacetic acid (DCA) and trichloroacetic acid (TCA), are thought to be hepatotoxic and carcinogenic in mice. The reactive products of glutathione conjugation, such as S-(1,2-dichlorovinyl)-L-cysteine (DCVC), and S-(1,2-dichlorovinyl) glutathione (DCVG), are associated with renal toxicity in rats. Recently, we developed a new analytical method for simultaneous assessment of these TCE metabolites in small-volume biological samples. Since important gaps remain in our understanding of the pharmacokinetics of TCE and its metabolites, we studied a time-course of DCA, TCA, DCVG and DCVG formation and elimination after a single oral dose of 2100 mg/kg TCE in male B6C3F1 mice. Based on systemic concentration-time data, we constructed multi-compartment models to explore the kinetic properties of the formation and disposition of TCE metabolites, as well as the source of DCA formation. We conclude that TCE-oxide is the most likely source of DCA. According to the best-fit model, bioavailability of oral TCE was ∼ 74%, and the half-life and clearance of each metabolite in the mouse were as follows: DCA: 0.6 h, 0.081 ml/h; TCA: 12 h, 3.80 ml/h; DCVG: 1.4 h, 16.8 ml/h; DCVC: 1.2 h, 176 ml/h. In B6C3F1 mice, oxidative metabolites are formed in much greater quantities (∼ 3600 fold difference) than glutathione-conjugative metabolites. In addition, DCA is produced to a very limited extent relative to TCA, while most of DCVG is converted into DCVC. These pharmacokinetic studies provide insight into the kinetic properties of four key biomarkers of TCE toxicity in the mouse, representing novel information that can be used in risk assessment.

  19. Thermochemistry of 1,3-diethylbarbituric and 1,3-diethyl-2-thiobarbituric acids: Experimental and computational study

    International Nuclear Information System (INIS)

    Notario, Rafael; Roux, María Victoria; Ros, Francisco; Emel’yanenko, Vladimir N.; Zaitsau, Dzmitry H.; Verevkin, Sergey P.

    2014-01-01

    Highlights: • Enthalpies of formation in condensed phase have been obtained. • Enthalpy of vaporization of 1,3-diethylbarbituric acid has been determined. • Enthalpy of sublimation of 1,3-diethyl-2-thiobarbituric acid has been determined. • Gas-phase enthalpies of formation have been obtained. • Gas-phase enthalpies of formation have been calculated at G3 and G4 levels. - Abstract: This paper reports an experimental and computational thermochemical study on two barbituric acid derivatives, viz. 1,3-diethylbarbituric acid and 1,3-diethyl-2-thiobarbituric acid. Values of standard molar enthalpies of formation in the gas phase at T = 298.15 K have been derived from experiment. Energies of combustion were measured by the static bomb combustion calorimetry in the case of 1,3-diethylbarbituric acid, and the rotating-bomb combustion calorimetry in the case of 1,3-diethyl-2-thiobarbituric acid. From the combustion energies, standard molar enthalpies of formation in the crystalline state at T = 298.15 K were calculated. The enthalpy of vaporization of 1,3-diethylbarbituric acid and enthalpy of sublimation of 1,3-diethyl-2-thiobarbituric acid were determined using the transpiration method. Combining calorimetric and transpiration results, values of −(611.9 ± 2.0) kJ · mol −1 and −(343.8 ± 2.2) kJ · mol −1 for the gas-phase enthalpies of formation at T = 298.15 K of 1,3-diethylbarbituric and 1,3-diethyl-2-thiobarbituric acids, respectively, were derived. Theoretical calculations at the G3 and G4 levels were performed, and a study of the molecular structure of the compounds has been carried out. Calculated enthalpies of formation were in very good agreement with the experimental values

  20. A new highly selective metabotropic excitatory amino acid agonist: 2-amino-4-(3-hydroxy-5-methylisoxazol-4-yl)butyric acid

    DEFF Research Database (Denmark)

    Bräuner-Osborne, Hans; Sløk, F A; Skjaerbaek, N

    1996-01-01

    The homologous series of acidic amino acids, ranging from aspartic acid (1) to 2-aminosuberic acid (5), and the corresponding series of 3-isoxazolol bioisosteres of these amino acids, ranging from (RS)-2-amino-2-(3-hydroxy-5-methylisoxazol-4-yl)acetic acid (AMAA, 6) to (RS)-2-amino-6-(3-hydroxy-5......-methylisoxazol-4-yl)hexanoic acid (10), were tested as ligands for metabotropic excitatory amino acid receptors (mGlu1 alpha, mGlu2, mGlu4a, and mGlu6). Whereas AMAA (6) and (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propinoic acid (AMPA, 7) are potent and highly selective agonists at N......-methyl-D-aspartic acid (NMDA) and AMPA receptors, respectively, the higher homologue of AMPA (7), (RS)-2-amino-4-(3-hydroxy-5-methylisoxazol-4-yl)butyric acid (homo-AMPA, 8), is inactive at ionotropic excitatory amino acid receptors. Homo-AMPA (8), which is a 3-isoxazolol bioisostere of 2-aminoadipic acid (3), was...

  1. The role of salicylic acid, L-ascorbic acid and oxalic acid in promoting the oxidation of alkenes with H(2)O(2) catalysed by [Mn(IV) (2)(O)(3)(tmtacn)(2)](2+)

    NARCIS (Netherlands)

    de Boer, Johannes W.; Alsters, Paul L.; Meetsma, Auke; Hage, Ronald; Browne, Wesley R.; Feringa, Ben L.

    2008-01-01

    The role played by the additives salicylic acid, L-ascorbic acid and oxalic acid in promoting the catalytic activity of [Mn(IV) (2)(O)(3)(tmtacn)(2)](PF(6))(2) {1(PF(6))(2), where tmtacn = N, N ', N ''-trimethyl-1,4,7-triazacyclononane} in the epoxidation and cis-dihydroxylation of alkenes with

  2. Omega-3 fatty acids: potential role in the management of early Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Gregory A Jicha

    2010-03-01

    Full Text Available Gregory A Jicha, William R MarkesberyUniversity of Kentucky Alzheimer’s Disease Center and the Sanders-Brown Center on Aging University of Kentucky College of Medicine, Lexington, KY, USAbstract: Omega-3 fatty acids are essential for brain growth and development. They play an important role throughout life, as critical modulators of neuronal function and regulation of oxidative stress mechanisms, in brain health and disease. Docosahexanoic acid (DHA, the major omega-3 fatty acid found in neurons, has taken on a central role as a target for therapeutic intervention in Alzheimer’s disease (AD. A plethora of in vitro, animal model, and human data, gathered over the past decade, highlight the important role DHA may play in the development of a variety of neurological and psychiatric disorders, including AD. Cross sectional and prospective cohort data have demonstrated that reduced dietary intake or low brain levels of DHA are associated with accelerated cognitive decline or the development of incipient dementia, including AD. Several clinical trials investigating the effects of omega-3 fatty acid supplementation in AD have been completed and all failed to demonstrate its efficacy in the treatment of AD. However, these trials produced intriguing data suggesting that the beneficial effects of omega-3 fatty acid supplementation may depend on the stage of disease, other dietary mediators, and apolipoprotein E status.Keywords: Alzheimer’s disease, omega-3 fatty acids, oxidative stress, clinical studies, treatment

  3. Tunable surface wettability and water adhesion of Sb2S3 micro-/nanorod films

    International Nuclear Information System (INIS)

    Zhong, Xin; Zhao, Huiping; Yang, Hao; Liu, Yunling; Yan, Guoping; Chen, Rong

    2014-01-01

    Antimony sulfide (Sb 2 S 3 ) films were successfully prepared by spin coating Sb 2 S 3 micro-/nanorods with different sizes on glass slides, which was synthesized via a facile and rapid microwave irradiation method. The prepared Sb 2 S 3 micro-/nanorods and films were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and water contact angle (CA). The as-prepared Sb 2 S 3 films exhibited different surface wettabilities ranging from superhydrophilicity to superhydrophobicity, which was strongly dependent on the diameter of Sb 2 S 3 micro-/nanorod. Sb 2 S 3 film made by nanorods possessed superhydrophobic surface and high water adhesive property. After surface modification with stearic acid, the superhydrophobic surface exhibited an excellent self-cleaning property owing to its low adhesive force. The clarification of three possible states including Wenzel's state, “Gecko” state and Cassie's state for Sb 2 S 3 film surfaces was also proposed to provide a better understanding of interesting surface phenomena on Sb 2 S 3 films.

  4. Maslinic acid modulates secreted phospholipase A2-IIA (sPLA2-IIA ...

    Indian Academy of Sciences (India)

    Wei Hsum Yap

    2018-03-29

    Mar 29, 2018 ... Further analysis revealed that sPLA2-IIA only induced modest LDL oxidation and that inhibitory .... COX-2, was also reduced in primary human chondrocyte, primary rat .... oxidation (4.34 nmol MDA/mg protein) compared to native ..... rheumatoid fibroblast-like synoviocyte arachidonic acid meta- bolism.

  5. Characterization of an Indole-3-Acetamide Hydrolase from Alcaligenes faecalis subsp. parafaecalis and Its Application in Efficient Preparation of Both Enantiomers of Chiral Building Block 2,3-Dihydro-1,4-Benzodioxin-2-Carboxylic Acid.

    Directory of Open Access Journals (Sweden)

    Pradeep Mishra

    Full Text Available Both the enantiomers of 2,3-dihydro-1,4-benzodioxin-2-carboxylic acid are valuable chiral synthons for enantiospecific synthesis of therapeutic agents such as (S-doxazosin mesylate, WB 4101, MKC 242, 2,3-dihydro-2-hydroxymethyl-1,4-benzodioxin, and N-[2,4-oxo-1,3-thiazolidin-3-yl]-2,3-dihydro-1,4-benzodioxin-2-carboxamide. Pharmaceutical applications require these enantiomers in optically pure form. However, currently available methods suffer from one drawback or other, such as low efficiency, uncommon and not so easily accessible chiral resolving agent and less than optimal enantiomeric purity. Our interest in finding a biocatalyst for efficient production of enantiomerically pure 2,3-dihydro-1,4-benzodioxin-2-carboxylic acid lead us to discover an amidase activity from Alcaligenes faecalis subsp. parafaecalis, which was able to kinetically resolve 2,3-dihydro-1,4-benzodioxin-2-carboxyamide with E value of >200. Thus, at about 50% conversion, (R-2,3-dihydro-1,4-benzodioxin-2-carboxylic acid was produced in >99% e.e. The remaining amide had (S-configuration and 99% e.e. The amide and acid were easily separated by aqueous (alkaline-organic two phase extraction method. The same amidase was able to catalyse, albeit at much lower rate the hydrolysis of (S-amide to (S-acid without loss of e.e. The amidase activity was identified as indole-3-acetamide hydrolase (IaaH. IaaH is known to catalyse conversion of indole-3-acetamide (IAM to indole-3-acetic acid (IAA, which is phytohormone of auxin class and is widespread among plants and bacteria that inhabit plant rhizosphere. IaaH exhibited high activity for 2,3-dihydro-1,4-benzodioxin-2-carboxamide, which was about 65% compared to its natural substrate, indole-3-acetamide. The natural substrate for IaaH indole-3-acetamide shared, at least in part a similar bicyclic structure with 2,3-dihydro-1,4-benzodioxin-2-carboxamide, which may account for high activity of enzyme towards this un-natural substrate. To

  6. Characterization of an Indole-3-Acetamide Hydrolase from Alcaligenes faecalis subsp. parafaecalis and Its Application in Efficient Preparation of Both Enantiomers of Chiral Building Block 2,3-Dihydro-1,4-Benzodioxin-2-Carboxylic Acid.

    Science.gov (United States)

    Mishra, Pradeep; Kaur, Suneet; Sharma, Amar Nath; Jolly, Ravinder S

    2016-01-01

    Both the enantiomers of 2,3-dihydro-1,4-benzodioxin-2-carboxylic acid are valuable chiral synthons for enantiospecific synthesis of therapeutic agents such as (S)-doxazosin mesylate, WB 4101, MKC 242, 2,3-dihydro-2-hydroxymethyl-1,4-benzodioxin, and N-[2,4-oxo-1,3-thiazolidin-3-yl]-2,3-dihydro-1,4-benzodioxin-2-carboxamide. Pharmaceutical applications require these enantiomers in optically pure form. However, currently available methods suffer from one drawback or other, such as low efficiency, uncommon and not so easily accessible chiral resolving agent and less than optimal enantiomeric purity. Our interest in finding a biocatalyst for efficient production of enantiomerically pure 2,3-dihydro-1,4-benzodioxin-2-carboxylic acid lead us to discover an amidase activity from Alcaligenes faecalis subsp. parafaecalis, which was able to kinetically resolve 2,3-dihydro-1,4-benzodioxin-2-carboxyamide with E value of >200. Thus, at about 50% conversion, (R)-2,3-dihydro-1,4-benzodioxin-2-carboxylic acid was produced in >99% e.e. The remaining amide had (S)-configuration and 99% e.e. The amide and acid were easily separated by aqueous (alkaline)-organic two phase extraction method. The same amidase was able to catalyse, albeit at much lower rate the hydrolysis of (S)-amide to (S)-acid without loss of e.e. The amidase activity was identified as indole-3-acetamide hydrolase (IaaH). IaaH is known to catalyse conversion of indole-3-acetamide (IAM) to indole-3-acetic acid (IAA), which is phytohormone of auxin class and is widespread among plants and bacteria that inhabit plant rhizosphere. IaaH exhibited high activity for 2,3-dihydro-1,4-benzodioxin-2-carboxamide, which was about 65% compared to its natural substrate, indole-3-acetamide. The natural substrate for IaaH indole-3-acetamide shared, at least in part a similar bicyclic structure with 2,3-dihydro-1,4-benzodioxin-2-carboxamide, which may account for high activity of enzyme towards this un-natural substrate. To the best of

  7. Occurrence and metabolism of 7-hydroxy-2-indolinone-3-acetic acid in Zea mays

    Science.gov (United States)

    Lewer, P.; Bandurski, R. S.

    1987-01-01

    7-Hydroxy-2-indolinone-3-acetic acid was identified as a catabolite of indole-3-acetic acid in germinating kernels of Zea mays and found to be present in amounts of ca 3.1 nmol/kernel. 7-Hydroxy-2-indolinone-3-acetic acid was shown to be a biosynthetic intermediate between 2-indolinone-3-acetic acid and 7-hydroxy-2-indolinone-3-acetic acid-7'-O-glucoside in both kernels and roots of Zea mays. Further metabolism of 7-hydroxy-2-[5-3H]-indolinone-3-acetic acid-7'-O-glucoside occurred to yield tritiated water plus, as yet, uncharacterized products.

  8. 40 CFR 721.3032 - Boric acid (H3BO2), zinc salt.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Boric acid (H3BO2), zinc salt. 721... Substances § 721.3032 Boric acid (H3BO2), zinc salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as boric acid (H3BO2), zinc salt (PMN P-97-553...

  9. 3-pyrazolone analogues of the 3-isoxazolol metabotropic excitatory amino acid receptor agonist homo-AMPA. Synthesis and pharmacological testing

    DEFF Research Database (Denmark)

    Zimmermann, D.; Janin, Y.L.; Brehm, L.

    1999-01-01

    the terminal carboxyl group has been replaced by various bioisosteric groups, such as phosphonic acid or 3-isoxazolol groups, have been shown to interact selectively with different subtypes of mGlu receptors. In this paper we report the synthesis of the 3-pyrazolone bioisosteres of a-AA, compounds (RS)-2-amino......-4-(1,2-dihydro-5-methyl-3-oxo-3H-pyrazol-4-yl)butyric acid (1) and (RS)-2-amino-4-(1,2-dihydro-1,5-dimethyl-3-oxo-3H-pyrazol-4-yl)butyric acid (2). At a number of steps in the reaction sequences used, the reactions took unexpected courses and provided products which could not be transformed......We have previously shown that the higher homologue of (S)-glutamic acid [(S)-Glu], (S)-a-aminoadipic acid [(S)-a-AA] is selectively recognized by the mGlu and mGlu subtypes of the family of metabotropic glutamic acid (mGlu) receptors. Furthermore, a number of analogues of (S)-a-AA, in which...

  10. Synthesis, spectroscopic, structural and optical studies of Ru2S3 nanoparticles prepared from single-source molecular precursors

    Science.gov (United States)

    Mbese, Johannes Z.; Ajibade, Peter A.

    2017-09-01

    Homonuclear tris-dithiocarbamato ruthenium(III) complexes, [Ru(S2CNR2)3] were prepared and characterized by spectroscopic techniques and thermogravimetric analyses. The thermogravimetric analyses (TGA) of the ruthenium complexes showed that the complexes decompose to ruthenium(III) sulfide nanoparticles. The ruthenium(III) complexes were dispersed in oleic acid and thermolysed in hexadecylamine to prepared oleic acid/hexadecylamine capped Ru2S3 nanoparticles. FTIR revealed that Ru2S3 nanoparticles are capped through the interaction of the -NH2 group of hexadecylamine HDA adsorbed on the surfaces of nanoparticles and it also showed that oleic acid (OA) is acting as both coordinating stabilizing surfactant and capping agent. EDS spectra revealed that the prepared nanoparticles are mainly composed of Ru and S, confirming the formation of Ru2S3 nanoparticles. Powder XRD confirms that the nanoparticles are in cubic phase. The inner morphology of nanoparticles obtained from transmission electron microscopy (TEM) showed nanoparticles with narrow particle size distributions characterized by an average diameter of 8.45 nm with a standard deviation of 1.6 nm. The optical band gap (Eg) determined from Tauc plot are in the range 3.44-4.18 eV.

  11. A New Method for the Synthesis of 2,3-Aziridino-2,3-dideoxyhexonamides and Their Conversion into 3-Amoni-2,3-dideoxyhexonic Acids

    DEFF Research Database (Denmark)

    Jørgensen, Christel Thea; Pedersen, Christian; Søtofte, Inger

    1998-01-01

    The new 2,3-Aziridino-2,3-dideoxyhexonamides 3 and 11 were prepared by a three-step procedure from commercially available D-glucono-1,5-lactone and D-gulono-1,4-lactone, respectively. The lactones were converted into methyl 3,4;5,6-di-O-isopropylidene-2-Omesyl esters 2 and 10, which upon treatmen...... with ammonia formed the title aziridino compounds. These were reductively cleaved by hydrazine to give 3-amino-2,3-dideoxyhexonic hydrazides 13 and 15, which were easily converted into corresponding lactone 14 and acid 16, respectively....

  12. Crystal Structures of KPC-2[beta]-Lactamase in Complex with 3-Nitrophenyl Boronic Acid and the Penam Sulfone PSR-3-226

    Energy Technology Data Exchange (ETDEWEB)

    Ke, Wei; Bethel, Christopher R.; Papp-Wallace, Krisztina M.; Pagadala, Sundar Ram Reddy; Nottingham, Micheal; Fernandez, Daniel; Buynak, John D.; Bonomo, Robert A.; van den Akker, Focco (Case Western); (Stokes); (SMU)

    2012-08-01

    Class A carbapenemases are a major threat to the potency of carbapenem antibiotics. A widespread carbapenemase, KPC-2, is not easily inhibited by {beta}-lactamase inhibitors (i.e., clavulanic acid, sulbactam, and tazobactam). To explore different mechanisms of inhibition of KPC-2, we determined the crystal structures of KPC-2 with two {beta}-lactamase inhibitors that follow different inactivation pathways and kinetics. The first complex is that of a small boronic acid compound, 3-nitrophenyl boronic acid (3-NPBA), bound to KPC-2 with 1.62-{angstrom} resolution. 3-NPBA demonstrated a Km value of 1.0 {+-} 0.1 {micro}M (mean {+-} standard error) for KPC-2 and blocks the active site by making a reversible covalent interaction with the catalytic S70 residue. The two boron hydroxyl atoms of 3-NPBA are positioned in the oxyanion hole and the deacylation water pocket, respectively. In addition, the aromatic ring of 3-NPBA provides an edge-to-face interaction with W105 in the active site. The structure of KPC-2 with the penam sulfone PSR-3-226 was determined at 1.26-{angstrom} resolution. PSR-3-226 displayed a K{sub m} value of 3.8 {+-} 0.4 {micro}M for KPC-2, and the inactivation rate constant (kinact) was 0.034 {+-} 0.003 s{sup -1}. When covalently bound to S70, PSR-3-226 forms a trans-enamine intermediate in the KPC-2 active site. The predominant active site interactions are generated via the carbonyl oxygen, which resides in the oxyanion hole, and the carboxyl moiety of PSR-3-226, which interacts with N132, N170, and E166. 3-NPBA and PSR-3-226 are the first {beta}-lactamase inhibitors to be trapped as an acyl-enzyme complex with KPC-2. The structural and inhibitory insights gained here could aid in the design of potent KPC-2 inhibitors.

  13. Improved wavelengths for the 1s2s3S1-1s2p3P0,2 transitions in helium-like Si12+

    International Nuclear Information System (INIS)

    Armour, I.A.; Myers, E.G.; Silver, J.D.; Traebert, E.; Oxford Univ.

    1979-01-01

    The wavelengths of the 1s2s 3 S 1 -1s2p 3 P 0 , 2 transitions in He-like Si 12+ have been remaesured to be 87.86 +- 0.01 nm and 81.48 +- 0.01 nm. The use of Rydberg lines for the calibration of fast beam spectra is discussed. (orig.)

  14. Synthesis of (3R)-3-(4-fluorophenylsulfonamido)-1,2,3,4-tetra-hydro-9-[4-3H] carbazolepropanoic acid

    International Nuclear Information System (INIS)

    Pleiss, Ulrich; Radtke, Martin; Schmitt, Peter

    1990-01-01

    (3R)-3-(4-Fluorophenylsulfonamido)-1,2,3,4-tetrahydro-9-[4- 3 H]carbazolepropanoic acid ( [ 3 H]BAY u 3405) (5) was synthesized by catalytic reduction of (3R)-3-(4-fluorophenylsulfonamido)-4-oxo-1,2,3,4-tetrahydro-9-carbazolepropanoic acid (4) with tritium. The precursor (4) was prepared by esterification and following oxidation of BAY u 3405 with 2,3-dichloro-5,6-dicyano-p-benzoquinone. 3 H NMR analysis of the final product showed the formation of [4α- 3 H]BAY us 3405 and [4β- 3 H]BAY u 3405 in a ratio of 1:1. (author)

  15. Studies on radiolysis of amino acids, (3)

    International Nuclear Information System (INIS)

    Oku, Tadatake

    1978-01-01

    For the purpose of investigating the radiolysis of amino acids and the safeness to radiation, the radiolytic mechanism and radio-sensitivity of sulfur-containing amino acids in aqueous solution in the presence of air or in the atmosphere of nitrogen were studied. Aqueous solutions of L-methionine, cysteine (both 1mM) and L-cystine (0.3mM) were irradiated with γ-ray of 60 Co at the dose of 4.2 - 2,640 x 10 3 rad. The amino acids and the radiolytic products were determined with an amino acid analyzer. The volatile sulfur compounds formed from γ-irradiated methionine were estimated by a flame photometric detector-gas chromatograph. From the results obtained, G values of the radiolysis of sulfur-containing amino acids and the products were calculated, and the radiolytic mechanisms of methionine, cysteine and cystine were proposed. The radio-sensitivity of sulfur-containing amino acids was shown as follows: cysteine (C3-SH) > methionine (C5, -SCH 3 ) > cystine (C 6 , -S-S-). Off-flavor development from γ-irradiated methionine when oxidizing agent was added was less than that when reducing agent was added. (Kobatake, H.)

  16. 3-[(E-(2,4-Dichloropbenzylideneamino]benzoic acid

    Directory of Open Access Journals (Sweden)

    Adnan Ashraf

    2011-01-01

    Full Text Available In the crystal of the title compound, C14H9Cl2NO2, inversion-related dimers with R22(8 ring motifs are formed by intermolecular O—H...O hydrogen bonding. The 3-aminobenzoic acid group and the 2,4-dichlobenzaldehyde moiety subtend a dihedral angle of 55.10 (2°. The H atom of the carboxyl group is disordered over two sites with equal occupancies.

  17. Tungsten phosphanylarylthiolato complexes [W{PhP(2-SC6H4)2-kappa3S,S',P} 2] and [W{P(2-SC6H4)3-kappa4S,S',S",P}2]: synthesis, structures and redox chemistry.

    Science.gov (United States)

    Hildebrand, Alexandra; Lönnecke, Peter; Silaghi-Dumitrescu, Luminita; Hey-Hawkins, Evamarie

    2008-09-14

    PhP(2-SHC6H4)2 (PS2H2) reacts with WCl6 with reduction of tungsten to give the air-sensitive tungsten(IV) complex [W{PhP(2-SC6H4)2-kappa(3)S,S',P}2] (1). 1 is oxidised in air to [WO{PhPO(2-SC6H4)2-kappa(3)S,S',O}{PhP(2-SC6H4)2-kappa(3)S,S',P}] (2). The attempted synthesis of 2 by reaction of 1 with iodosobenzene as oxidising agent was unsuccessful. [W{P(2-SC6H4)3-kappa(4)S,S',S",P}2] (3) was formed in the reaction of P(2-SHC6H4)3 (PS3H3) with WCl6. The W(VI) complex 3 contains two PS3(3-) ligands, each coordinated in a tetradentate fashion resulting in a tungsten coordination number of eight. The reaction of 3 with AgBF4 yields the dinuclear tungsten complex [W2{P(2-SC6H4)3-kappa(4)S,S',S",P}3]BF4 (4). Complexes 1-4 were characterised by spectral methods and X-ray structure determination.

  18. Synthesis and Transformations of di-endo-3-Aminobicyclo-[2.2.2]oct-5-ene-2-carboxylic Acid Derivatives

    Directory of Open Access Journals (Sweden)

    Márta Palkó

    2011-09-01

    Full Text Available all-endo-3-amino-5-hydroxybicyclo[2.2.2]octane-2-carboxylic acid (13 and all-endo-5-amino-6-(hydroxymethylbicyclo[2.2.2]octan-2-ol (10 were prepared via dihydro-1,3-oxazine or g-lactone intermediates by the stereoselective functionalization of an N-protected derivative of endo-3-aminobicyclo[2.2.2]oct-5-ene-2-carboxylic acid (2. Ring closure of b-amino ester 4 resulted in tricyclic pyrimidinones 15 and 16. The structures, stereochemistry and relative configurations of the synthesized compounds were determined by IR and NMR.

  19. Electron excitation cross sections for the 2s(2)2p(3)4S(O) -- 2s(2)2p(3)2D(O) (forbidden) and 4S(O) -- 2s2p(4) 4P (resonance) transitions in O II

    Science.gov (United States)

    Zuo, M.; Smith, Steven J.; Chutjian, A.; Williams, I. D.; Tayal, S. S.; Mclaughlin, Brendan M.

    1995-01-01

    Experimental and theoretical excitation cross sections are reported for the first forbidden transition 4S(O) -- 2S(2)2p(3) 2D(O) (lambda-lambda 3726, 3729) and the first allowed (resonance) transition 4S(O) -- 2s2p(4) 4P(lambda-833) in O II. Use is made of electron energy loss and merged-beams methods. The electron energy range covered is 3.33 (threshold) to 15 eV for the S -- D transition, and 14.9 (threshold) to 40 eV for the S -- P transition. Care was taken to assess and minimize the metastable fraction of the O II beam. An electron mirror was designed and tested to reflect inelastically backscattered electrons into the forward direction to account for the full range of polar scattering angles. Comparisons are made between present experiments and 11-state R-matrix calculations. Calculations are also presented for the 4S(O) -- 2s(2)2p(3)2P(O) (lambda-2470) transition.

  20. Characterization of Cu3SbS3 thin films grown by thermally diffusing Cu2S and Sb2S3 layers

    OpenAIRE

    Hussain, Arshad; Ahmed, Rashid; Ali, N.; Shaari, A.; Luo, Jing-Ting; Fu, Yong Qing

    2017-01-01

    Copper antimony sulphide (Cu3SbS3) with a p-type conductivity and optical band gaps in the range of 1.38 to 1.84 eV is considered to be a promising solar harvesting material with non-toxic and economical elements. In this study, we reported the fabrication of Cu3SbS3 thin films using successive thermal evaporation of Cu2S and Sb2S3 layers followed by annealing in an argon atmosphere at a temperature range of 300-375°C. The structural and optical properties of the as-deposited and annealed fil...

  1. Stereospecific ligands and their complexes. VI. The crystal structure of (S,S-ethylenediamine-N,N’-di-2-propanoic acid hydrochloride, (S,S-H2eddp•HCl

    Directory of Open Access Journals (Sweden)

    VERICA V. GLODJOVIĆ

    2011-07-01

    Full Text Available (S,S-Ethylenediamine-N,N’-di-2-propanoic acid hydrochloride, (S,S-H2eddp·HCl, was prepared and its crystal structure determined. The compound was characterized by infrared and 1H- and 13C-NMR spectroscopy. It forms P1 in the space group of a triclinic crystal system with a = 5.3902(2 Å, b = 5.8967(2 Å, c = 10.3319(2 Å, a = 99.625(2°, b = 91.645(2°, g = 109.995(2° and Z = 1.

  2. Random poly(amino acid)s synthesized by ring opening polymerization as additives in the biomimetic mineralization of CaCO3

    NARCIS (Netherlands)

    Dmitrovic, V.; Habraken, G.J.M.; Hendrix, M.M.R.M.; Habraken, W.J.E.M.; Heise, A.; With, de G.; Sommerdijk, N.A.J.M.

    2012-01-01

    Biominerals such as bones, teeth and seashells, very often have advanced material properties and are a source of inspiration for material chemists. As in biological systems acidic proteins play an important role in regulating the formation of CaCO3 biominerals, we employ poly(amino acid)s to mimic

  3. Apports spontanés en acides gras oméga 3 chez des diabétiques de type 2 tunisiens

    OpenAIRE

    Jamoussi Henda; Chaabouni Salma; Gammoudi Amel; Mahjoub Faten; Ounaissa Kamilia; Berriche Olfa; Amrouche Chiraz; Blouza Samira

    2014-01-01

    Il est admis à l’unanimité que les acides gras oméga 3 ont de multiples bénéfices pour la santé et plus précisément des effets protecteurs contre les maladies cardiovasculaires et neurodégénératives. L’objectif de ce travail était d’estimer les apports spontanés en acides alphalinolénique (ALA), docosahexaénoïque (DHA), éicosapentaénoïque (EPA) et linoléique (LA). Cette étude d’observation a été réalisée auprès de 42 diabétiques de type ...

  4. Z-2-(β-D-glucopyranosyloxy)-3-phenylpropenoic acid, an α-hydroxy acid from rooibos (Aspalathus linearis) with hypoglycemic activity

    DEFF Research Database (Denmark)

    Muller, C.J.F.; Joubert, Elizabeth; Pheiffer, Carmen

    2013-01-01

    Scope: The rare enolic phenylpyruvic acid glucoside, Z-2-(β-D-glucopyranosyloxy)-3-phenylpropenoic acid (PPAG) is one of the major constituents of fermented rooibos infusions. 3-Phenylpyruvic acid (2-oxo-3-phenylpropanoic acid) (PPA), without the sugar moiety and with a keto instead of enolic arr...

  5. Ultraviolet emission from low resistance Cu2SnS3/SnO2 and CuInS2/Sn:In2O3 nanowires

    Directory of Open Access Journals (Sweden)

    E. Karageorgou

    2014-11-01

    Full Text Available SnO2 and Sn:In2O3 nanowires were grown on Si(001, and p-n junctions were fabricated in contact with p-type Cu2S which exhibited rectifying current–voltage characteristics. Core-shell Cu2SnS3/SnO2 and CuInS2/Sn:In2O3 nanowires were obtained by depositing copper and post-growth processing under H2S between 100 and 500 °C. These consist mainly of tetragonal rutile SnO2 and cubic bixbyite In2O3. We observe photoluminescence at 3.65 eV corresponding to band edge emission from SnO2 quantum dots in the Cu2SnS3/SnO2 nanowires due to electrostatic confinement. The Cu2SnS3/SnO2 nanowires assemblies had resistances of 100 Ω similar to CuInS2/In2O3 nanowires which exhibited photoluminescence at 3.0 eV.

  6. Substituted thiobenzoic acid S-benzyl esters as potential inhibitors of a snake venom phospholipase A2: Synthesis, spectroscopic and computational studies

    Science.gov (United States)

    Henao Castañeda, I. C.; Pereañez, J. A.; Jios, J. L.

    2012-11-01

    4-Chlorothiobenzoic acid S-benzyl ester (I), 3-nitrothiobenzoic acid S-benzyl ester (II), 4-nitrothiobenzoic acid S-benzyl ester (III) and 4-methylthiobenzoic acid S-benzyl ester (IV) were prepared and characterized by 1H and 13C NMR, Mass spectrometry and IR spectroscopy. Quantum chemical calculations were performed with Gaussian 09 to calculate the geometric parameters and vibrational spectra. Phospholipase A2 (PLA2) was purified from Crotalus durissus cumanensis venom by molecular exclusion chromatography, followed by reverse phase-high performance liquid chromatography. Two studies of the inhibition of phospholipase A2 activity were performed using phosphatidilcholine and 4-nitro-3-octanoyloxybenzoic acid as substrates, in both cases compound II showed the best inhibitory ability, with 74.89% and 69.91% of inhibition, respectively. Average percentage of inhibition was 52.49%. Molecular docking was carried out with Autodock Vina using as ligands the minimized structures of compounds (I-IV) and as protein PLA2 (PDB code 2QOG). The results suggest that compounds I-IV could interact with His48 at the active site of PLA2. In addition, all compounds showed Van der Waals interactions with residues from hydrophobic channel of the enzyme. This interaction would impede normal catalysis cycle of the PLA2.

  7. Sulfuric acid baking and leaching of spent Co-Mo/Al2O3 catalyst.

    Science.gov (United States)

    Kim, Hong-In; Park, Kyung-Ho; Mishra, Devabrata

    2009-07-30

    Dissolution of metals from a pre-oxidized refinery plant spent Co-Mo/Al(2)O(3) catalyst have been tried through low temperature (200-450 degrees C) sulfuric acid baking followed by mild leaching process. Direct sulfuric acid leaching of the same sample, resulted poor Al and Mo recoveries, whereas leaching after sulfuric acid baking significantly improved the recoveries of above two metals. The pre-oxidized spent catalyst, obtained from a Korean refinery plant found to contain 40% Al, 9.92% Mo, 2.28% Co, 2.5% C and trace amount of other elements such as Fe, Ni, S and P. XRD results indicated the host matrix to be poorly crystalline gamma- Al(2)O(3). The effect of various baking parameters such as catalyst-to-acid ratio, baking temperature and baking time on percentage dissolutions of metals has been studied. It was observed that, metals dissolution increases with increase in the baking temperature up to 300 degrees C, then decreases with further increase in the baking temperature. Under optimum baking condition more than 90% Co and Mo, and 93% Al could be dissolved from the spent catalyst with the following leaching condition: H(2)SO(4)=2% (v/v), temperature=95 degrees C, time=60 min and Pulp density=5%.

  8. 3H-1,2-Benzodithiole-3-thione

    Directory of Open Access Journals (Sweden)

    Khaled Boukebbous

    2016-10-01

    Full Text Available The almost planar (r.m.s. deviation = 0.034 Å title compound, C7H4S3, was synthesized by reacting 2,2-dithiodibenzoic acid with phosphorus pentasulfide in xylene solution. In the crystal, short S...S [3.3727 (14, 3.3765 (13 and 3.4284 (13 Å] contacts and aromatic π–π stacking [shortest centroid–centroid separation = 3.618 (2 Å] are observed.

  9. Omega-3 fatty acids (image)

    Science.gov (United States)

    Omega-3 fatty acids are a form of polyunsaturated fat that the body derives from food. Omega-3s (and omega-6s) are known as essential fatty acids (EFAs) because they are important for good health. ...

  10. Specific non-bonding contacts in the crystal structure of [Mo33-S)(μ-S2)3(S2CNEt2)3]Cl0.53Br0.47 solid solution

    International Nuclear Information System (INIS)

    Virovets, A.V.; Volkov, O.V.

    2000-01-01

    Solid solution [Mo 3 S 7 (dtc) 3 ]Cl 0.53 Br 0.47 (dtc diethyl-dithiocarbamate) featuring the following parameters of monoclinic all: a = 14.541(2), b = 12.407(2), c = 18.117(2) A, β = 90.032(9) deg, sp.gr. P2 1 /n, Z = 4, d cal = 2.107 g/cm 3 , was studied by the method of X-ray diffraction analysis. Formation of ionic pairs with axial contact 3S ax ...Br, its length 3.028-3.105 A, in the compound structure was ascertained. For compounds [Mo 3 S 7 (dtc) 3 ] Hal (Hal = Cl, Br, I) a regular growth in S...Hal distances in the series Cl-Br-I was pointed out, meanwhile the distances remained shorted than the van-der-Waals sums of sulfur and halogen radii [ru

  11. Experimental and theoretical study of pure and doped crystals: Gd2O2S, Gd2O2S:Eu3+ and Gd2O2S:Tb3+

    Science.gov (United States)

    Wang, Fei; Chen, Xiumin; Liu, Dachun; Yang, Bin; Dai, Yongnian

    2012-08-01

    Quantum chemistry and experimental method were used to study on pure and doped Gd2O2S crystals in this paper. The band structure and DOS diagrams of pure and doped Gd2O2S crystals which calculated by using DFT (Density Functional Theory) method were illustrated to explain the luminescent properties of impurities in crystals. The calculations of the crystal structure were finished by using the program of CASTEP (Cambridge Sequential Total Energy Package). The samples showed the characteristic emissions of Tb3+ ions with 5D4-7FJ transitions and Eu3+ ions with 5D0-7FJ transitions which emit pure green luminescence and red luminescence respectively. The experimental excitation spectra of Tb3+ and Eu3+ doped Gd2O2S are in agreement of the DOS diagrams over the explored energy range, which has allowed a better understanding of different luminescence mechanisms of Tb3+ and Eu3+ in Gd2O2S crystals.

  12. [(4S,5S-2,2-Dimethyl-1,3-dioxolane-4,5-diyl]bis[N-(thiophen-2-ylmethylidenemethanamine

    Directory of Open Access Journals (Sweden)

    Yan Jiang

    2012-02-01

    Full Text Available In the title compound, C17H20N2O2S2, the five-membered heterocycle exhibits an envelope conformation and the molecular chirality and configuration are well preserved from l-tartaric acid. The dihedral angle between the two thiophene rings is 17.0 (2°. In the crystal, molecules are linked by C—H...O and C—H...S hydrogen interactions, which are effective in the stabilization of the crystal structure.

  13. S-Alkylated/aralkylated 2-(1H-indol-3-yl-methyl)-1,3,4- oxadiazole-5 ...

    African Journals Online (AJOL)

    ylmethyl)-1,3,4- oxadiazole-5-thiol derivatives. Methods: 2-(1H-indol-3-yl)acetic acid (1) was reacted with absolute ethanol and catalytic amount of sulfuric acid to form ethyl 2-(1H-indol-3-yl)acetate (2) which was transformed to 2-(1H-indol-3- ...

  14. The synthesis of [2-3H2] taurine and [2-3H2] hypotaurine

    International Nuclear Information System (INIS)

    Fellman, J.H.

    1981-01-01

    The synthesis of [2- 3 H 2 ]-2-aminoethanesulfonate [2- 3 H]-taurine by the reduction of cyanomethanesulfonic acid with tritium gas is described. The conversion of [2- 3 H]-taurine and its 14 C and 35 S isotopic forms to 2-aminoethanesulfinate (hypotaurine) was accomplished by converting taurine to its corresponding sulfonyl chloride and reducing the latter with metallic zinc. (author)

  15. The elusive 2s3s1S level in B II

    International Nuclear Information System (INIS)

    Martinson, I; Awaya, Y; Ekberg, J O; Kink, I; Mannervik, S; Ryabtsev, A N

    2003-01-01

    It has been known for nearly 30 years that the theoretical and experimental values for the energy of the 2s3s 1 S level in singly ionized boron, B II, differ strongly. Since there is much better agreement for other B II levels, it has been concluded that the experimental value for 2s3s 1 S must be revised. Despite a number of recordings over the years of sliding-spark, hollow cathode and beam-foil spectra, this level has not been located. We have now performed another beam-foil experiment, using higher resolution and sensitivity than in most previous studies. By combining these new data with previous results, we have identified transitions from the 2s4p, 2s5p and 2p3s 1 P levels to 2s3s 1 S, the excitation energy (137 622 ± 3 cm -1 ) of which is now well established and in excellent agreement with theoretical predictions

  16. Synthesis, antimicrobial, and anti-inflammatory activities of novel 2-[3-(1-adamantyl)-4-substituted-5-thioxo-1,2,4-triazolin-1-yl] acetic acids, 2-[3-(1-adamantyl)-4-substituted-5-thioxo-1,2,4-triazolin-1-yl]propionic acids and related derivatives.

    Science.gov (United States)

    Al-Deeb, Omar A; Al-Omar, Mohamed A; El-Brollosy, Nasser R; Habib, Elsayed E; Ibrahim, Tarek M; El-Emam, Ali A

    2006-01-01

    The reaction of 3-(1-adamantyl)-4-substituted-1,2,4-triazoline-5-thiones 3a-g with sodium chloroacetate, in ethanolic sodium hydroxide yielded the corresponding N1-acetic acid derivatives 4a-g. The interaction of 3a-g with ethyl 2-bromopropionate in acetone, in the presence of potassium carbonate, yielded the corresponding N1-ethyl propionate derivatives 5a-g, which upon hydrolysis with aqueous sodium hydroxide afforded the corresponding propionic acid derivatives 6a-g. Similarly, the reaction of 3-(1-adamantyl)-4-amino-1,2,4-triazoline-5-thione 7 with sodium chloroacetate in ethanolic sodium hydroxide yielded the corresponding N1-acetic acid derivative 8. On the other hand, the reaction of 2-(1-adamantyl)-1,3,4-oxadiazoline-5-thione 9 with sodium chloroacetate yielded the corresponding S-acetic acid derivative 10. Compounds 4a-g, 5b, 5c, 5g, 6a-g, 8 and 10 were tested for in vitro activities against a panel of Gram-positive and Gram-negative bacteria and the yeast-like pathogenic fungus Candida albicans. Several derivatives produced good or moderate activities particularly against Bacillus subtilis. In addition, the in vivo anti-inflammatory activities of these compounds were determined using the carrageenin-induced paw oedema method in rats. Compounds 4a, 4b, 4e, 4f, 6f, 6g and 10 produced good dose-dependent anti-inflammatory activities.

  17. Primordial Synthesis of Amines and Amino Acids in a 1958 Miller H2S-Rich Spark Discharge Experiment

    Science.gov (United States)

    Parker, Eric T.; Cleaves, Henderson J.; Dworkin, Jason P.; Glavin, Daniel P.; Callahan, Michael; Aubrey, Andrew; Lazcano, Antonio; Bada, Jeffrey L.

    2011-01-01

    Archived samples from a previously unreported 1958 Stanley Miller electric discharge experiment containing hydrogen sulfide (H2S) were recently discovered and analyzed using high-performance liquid chromatography and time-of-flight mass spectrometry. We report here the detection and quantification of primary amine-containing compounds in the original sample residues, which were produced via spark discharge using a gaseous mixture of H2S, CH4, NH3, and CO2. A total of 23 amino acids and 4 amines, including 7 organosulfur compounds, were detected in these samples. The major amino acids with chiral centers are racemic within the accuracy of the measurements, indicating that they are not contaminants introduced during sample storage. This experiment marks the first synthesis of sulfur amino acids from spark discharge experiments designed to imitate primordia! environments. The relative yield of some amino acids, in particular the isomers of aminobutyric acid, are the highest ever found in a spark discharge experiment. The simulated primordial conditions used by Miller may serve as a model for early volcanic plume chemistry and provide insight to the possible roles such plumes may have played in abiotic organic synthesis. Additionally, the overall abundances of the synthesized amino acids in the presence of H2S are very similar to the abundances found in some carbonaceous meteorites, suggesting that H2S may have played an important role in prebiotic reactions in early solar system environments.

  18. Benzoate Acid-Dependent Lattice Dimension of Co-MOFs and MOF-Derived CoS2@CNTs with Tunable Pore Diameters for Supercapacitors.

    Science.gov (United States)

    Zou, Kang-Yu; Liu, Yi-Chen; Jiang, Yi-Fan; Yu, Cheng-Yan; Yue, Man-Li; Li, Zuo-Xi

    2017-06-05

    Herein three novel cobalt metal-organic frameworks (Co-MOFs) with similar ingredients, [Co(bib)(o-bdc)] ∞ (1), [Co 2 (bib) 2 (m-bdc) 2 ] ∞ (2), and {[Co(bib)(p-bdc)(H 2 O)](H 2 O) 0.5 } ∞ (3), have been synthesized from the reaction of cobalt nitrate with 1,4-bis(imidazol-1-yl)benzene (bib) and structure-related aromatic acids (1,2-benzenedicarboxylic acid = o-bdc, 1,3-benzenedicarboxylic acid = m-bdc, and 1,4-benzenedicarboxylic acid = p-bdc) by the solvothermal method. It is aimed to perform systematic research on the relationship among the conformation of benzoate acid, lattice dimension of Co-MOF, and pore diameter of MOF-derived carbon composite. Through the precursor strategy, Co-MOFs 1-3 have been utilized to synthesize porous cobalt@carbon nanotube composites (Co@CNTs). After the in situ gas-sulfurization, secondary composites CoS 2 @CNTs were successfully obtained, which kept similar morphologies of corresponding Co@CNTs without destroying previous highly dispersed structures. Co-MOFs and two series of composites (Co@CNTs and CoS 2 @CNTs) have been well characterized. Topology and Brunauer-Emmett-Teller analyses elucidate that the bdc 2- ion could control the pore diameters of MOF-derived carbon composites by adjusting the lattice dimension of Co-MOFs. The systematic studies on electrochemical properties demonstrate that (p)-CoS 2 @CNT possesses hierarchical morphology, moderate specific surface area, proper pore diameter distribution, and high graphitization, which lead to remarkable specific capacitances (839 F g -1 at 5 mV s -1 and 825 F g -1 at 0.5 A g -1 ) in 2 M potassium hydroxide solution. In addition, the (p)-CoS 2 @CNT electrode exhibits good electrochemical stability and still retains 82.9% of initial specific capacitance at the current density of 1 A g -1 after 5000 cycles.

  19. Synthesis and pharmacology of 3-isoxazolol amino acids as selective antagonists at group I metabotropic glutamic acid receptors

    DEFF Research Database (Denmark)

    Madsen, U; Bräuner-Osborne, H; Frydenvang, Karla Andrea

    2001-01-01

    Using ibotenic acid (2) as a lead, two series of 3-isoxazolol amino acid ligands for (S)-glutamic acid (Glu, 1) receptors have been developed. Whereas analogues of (RS)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid [AMPA, (RS)-3] interact selectively with ionotropic Glu receptors (i......GluRs), the few analogues of (RS)-2-amino-3-(3-hydroxy-5-isoxazolyl)propionic acid [HIBO, (RS)-4] so far known typically interact with iGluRs as well as metabotropic Glu receptors (mGluRs). We here report the synthesis and pharmacology of a series of 4-substituted analogues of HIBO. The hexyl analogue 9 was shown...... to originate in (S)-11 (EC(50) = 395 microM, K(b) = 86 and 90 microM, respectively). Compound 9, administered icv, but not sc, was shown to protect mice against convulsions induced by N-methyl-D-aspartic acid (NMDA). Compounds 9 and 11 were resolved using chiral HPLC, and the configurational assignments...

  20. 2-(5-Fluoro-3-isopropylsulfanyl-1-benzofuran-2-ylacetic acid

    Directory of Open Access Journals (Sweden)

    Pil Ja Seo

    2011-11-01

    Full Text Available The title compound, C13H13FO3S, was prepared by alkaline hydrolysis of ethyl 2-(5-fluoro-3-isopropylsulfanyl-1-benzofuran-2-ylacetate. In the crystal, the carboxy groups are involved in intermolecular O—H...O hydrogen bonds, which link the molecules into centrosymmetric dimers. These dimers are further packed into stacks along the b axis by a slipped π–π interaction between the furan and benzene rings of neighbouring molecules [centroid–centroid distance = 3.727 (2 Å, interplanar distance = 3.465 (2 Å and slippage = 1.373 (2 Å]. The crystal structure also exhibits a short S...O contact [S...O = 3.219 (2 Å].

  1. A simple synthesis of L-[35S]cysteine sulfinic acid

    International Nuclear Information System (INIS)

    Spears, R.M.; Martin, D.L.

    1981-01-01

    The synthesis of L-[ 35 S]cysteine sulfinic acid (L-2-amino-3-[ 35 S]sulfino-propanoic acid) in 65% yield from S-[ 35 S]cystine is described. The procedure was designed for use with milligram quantities of starting material and requires no purification of intermediates. L-[ 35 S]Cystine was converted first to its thiosulfonate. Subsequent reaction of the thiosulfonate with ammonium hydroxide generated L-[ 35 S]cysteine sulfinic acid and L-[ 35 S]cystine as the major products. The L-[ 35 S]cystine was recovered and reprocessed thereby increasing the yield. (author)

  2. Structure and properties of GeS2-Ga2S3-CdI2 chalcohalide glasses

    International Nuclear Information System (INIS)

    Guo Haitao; Zhai Yanbo; Tao Haizheng; Dong Guoping; Zhao Xiujian

    2007-01-01

    Chalcohalide glasses in the GeS 2 -Ga 2 S 3 -CdI 2 pseudo-ternary system were prepared by 3-5N pure raw materials. Structures of these glasses were studied with Raman spectroscopy. Several properties, namely, glass transition temperature, optical transmission, density and microhardness have also been measured. Based on the Raman spectra, it can be speculated that the glass network is mainly constituted by [GeS 4 ], [GaS 4 ] tetrahedra with some mixed-anion tetrahedra [S 3 GeI], [S 2 GeI 2 ] and [S 3 GaI], which are interconnected by bridging sulfurs and/or short S-S chains. In the glasses with little CdI 2 , some part of Ge(Ga) exists in the forms of the ethane-like units [S 3 (Ga)Ge-Ge(Ga)S 3 ] because of the lack of sulfur, but the amount of these units will decrease with the addition of CdI 2 . Additionally, in the glasses with high content of CdI 2 , some [CdI n ] structural units (s.u.) will be formed and dispersed homogenously in glass network. These novel glasses have relatively high glass transition temperatures (T g ranges from 512 to 670 K), good thermal stabilities (the maximum of difference between T x and T g is 185 K) and UV-vis optical transmission, large densities (d ranges from 3.162 to 3.863 g/cm 3 ) and microhardness (large than 150 kg/mm 2 generally). All properties evolutions follow the structural variations

  3. Synthesis of novel 2,5-disubstituted-1,3,4-selenadiazoles from fatty acid hydrazides

    Directory of Open Access Journals (Sweden)

    Himani Varshney

    2018-01-01

    Full Text Available A series of novel unsaturated hydroxy and non-hydroxy fatty acid residue substituted 1,3,4-selenadiazoles were described here. These derivatives were synthesized from the reaction of fatty acid hydrazide 1(a–d with acetyl chloride in the presence of anhydrous sodium carbonate in tetrahydrofuran and water at 0 °C, to form N′-acetyl undec-10-enoic hydrazide 2a, N′-acetyl-(9Z-octadec-9-enoic hydrazide 2b, N′-acetyl-(9Z, 12R-12-hydroxy-9-enoic hydrazide 2c, and N′-acetyl-(9R, 12Z-9-hydroxy-12-enoic hydrazide 2d. Then these hydrazines (dicarbonyl compound on reaction with Woollin’s reagent (WR in toluene led to the corresponding 2-(dec-9′-enyl-5-methyl-1,3,4-selenadiazole 3a, 2-[(8′Z-heptadec-8′-enyl]-5-methyl-1,3,4-selenadiazole 3b, 2-[(8′Z, 11′R-11′-hydroxy-octadec-8′-enyl]-5-methyl-1,3,4-selenadiazole 3c, and 2-[(8′R, 11′Z-8′-hydroxy-octadec-11′-enyl]-5-methyl-1,3,4-selenadiazole 3d, respectively. These synthesized compounds were characterized on the basis of IR, 1H NMR, 13C NMR, mass spectra and elemental analysis results.

  4. On the “compositional threshold“ in GeS2-Sb2S3, GeSe2-Sb2Se3 and GeS2-Bi2S3 glasses

    Czech Academy of Sciences Publication Activity Database

    Tichý, Ladislav; Tichá, H.

    2015-01-01

    Roč. 152, 15 February (2015), s. 1-3 ISSN 0254-0584 Institutional support: RVO:61389013 Keywords : chalcogenide glasses * hetero three atom linkages * eutectic compositon Subject RIV: CA - Inorganic Chemistry Impact factor: 2.101, year: 2015

  5. Insight into a conformation of the PNA-PNA duplex with (2‧R,4‧R)- and (2‧R,4‧S)-prolyl-(1S,2S)-2-aminocyclopentanecarboxylic acid backbones

    Science.gov (United States)

    Maitarad, Amphawan; Poomsuk, Nattawee; Vilaivan, Chotima; Vilaivan, Tirayut; Siriwong, Khatcharin

    2018-04-01

    Suitable conformations for peptide nucleic acid (PNA) self-hybrids with (2‧R,4‧R)- and (2‧R,4‧S)-prolyl-(1S,2S)-2-aminocyclopentanecarboxylic acid backbones (namely, acpcPNA and epi-acpcPNA, respectively) were investigated based on molecular dynamics simulations. The results revealed that hybridization of the acpcPNA was observed only in the parallel direction, with a conformation close to the P-type structure. In contrast, self-hybrids of the epi-acpcPNA were formed in the antiparallel and parallel directions; the antiparallel duplex adopted the B-form conformation, and the parallel duplex was between B- and P-forms. The calculated binding energies and the experimental data indicate that the antiparallel epi-acpcPNA self-hybrid was more stable than the parallel duplex.

  6. Beneficial effect(s) of n-3 fatty acids in cardiovascular diseases: but, why and how?

    Science.gov (United States)

    Das, U N

    2000-12-01

    Low rates of coronary heart disease was found in Greenland Eskimos and Japanese who are exposed to a diet rich in fish oil. Suggested mechanisms for this cardio-protective effect focused on the effects of n-3 fatty acids on eicosanoid metabolism, inflammation, beta oxidation, endothelial dysfunction, cytokine growth factors, and gene expression of adhesion molecules; But, none of these mechanisms could adequately explain the beneficial actions of n-3 fatty acids. One attractive suggestion is a direct cardiac effect of n-3 fatty acids on arrhythmogenesis. N-3 fatty acids can modify Na+ channels by directly binding to the channel proteins and thus, prevent ischemia-induced ventricular fibrillation and sudden cardiac death. Though this is an attractive explanation, there could be other actions as well. N-3 fatty acids can inhibit the synthesis and release of pro-inflammatory cytokines such as tumor necrosis factoralpha (TNFalpha) and interleukin-1 (IL-1) and IL-2 that are released during the early course of ischemic heart disease. These cytokines decrease myocardial contractility and induce myocardial damage, enhance the production of free radicals, which can also suppress myocardial function. Further, n-3 fatty acids can increase parasympathetic tone leading to an increase in heart rate variability and thus, protect the myocardium against ventricular arrhythmias. Increased parasympathetic tone and acetylcholine, the principle vagal neurotransmitter, significantly attenuate the release of TNF, IL-1beta, IL-6 and IL-18. Exercise enhances parasympathetic tone, and the production of anti-inflammatory cytokine IL-10 which may explain the beneficial action of exercise in the prevention of cardiovascular diseases and diabetes mellitus. TNFalpha has neurotoxic actions, where as n-3 fatty acids are potent neuroprotectors and brain is rich in these fatty acids. Based on this, it is suggested that the principle mechanism of cardioprotective and neuroprotective action(s) of n-3

  7. [Shikimic acid inhibits the degranulation and histamine release in RBL-2H3 cells].

    Science.gov (United States)

    Chen, Xianyong; Zheng, Qianqian; Liu, Wei; Yu, Lingling; Wang, Jinling; Li, Shigang

    2017-05-01

    Objective To study the effects of shikimic acid on the proliferation of rat RBL-2H3 cells and the degranulation of the cells induced by C48/80 and its mechanism. Methods MTT assay was performed to measure the proliferation of RBL-2H3 cells treated with 3, 10, 30 μg/mL shikimic acid. Toluidine blue staining was used to observe the degranulation of RBL-2H3 cells. The release of β-hexosaminidase from RBL-2H3 cells treated with 0, 12.5, 25, 50, 80, 100 μg/mL C48/80 was determined by substrate assay. ELISA was used to detect the histamine content in the supernatant of each treated group. Results Shikimic acid at 3, 10, 300 μg/mL had no obvious inhibitory effect on the proliferation of RBL-2H3 cells. There was a dose-effect relationship between the degranulation of RBL-2H3 cells and C48/80 concentration. Shikimic acid inhibited the degranulation of RBL-2H3 cells compared with the positive control group, the β-hexosaminidase release rate and histamine release were significantly reduced in RBL-2H3 cells treated with shikimic acid and C48/80. Conclusion Shikimic acid can inhibit the degranulation of RBL-2H3 cells and reduce histamine release.

  8. Tunable surface wettability and water adhesion of Sb{sub 2}S{sub 3} micro-/nanorod films

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Xin; Zhao, Huiping [Key Laboratory for Green Chemical Process of Ministry of Education and Hubei Novel Reactor and Green Chemical Technology Key Laboratory, Wuhan Institute of Technology, Xiongchu Street, Wuhan 430073 (China); Yang, Hao, E-mail: hyangwit@hotmail.com [Key Laboratory for Green Chemical Process of Ministry of Education and Hubei Novel Reactor and Green Chemical Technology Key Laboratory, Wuhan Institute of Technology, Xiongchu Street, Wuhan 430073 (China); Liu, Yunling [State Key laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012 (China); Yan, Guoping [Key Laboratory for Green Chemical Process of Ministry of Education and Hubei Novel Reactor and Green Chemical Technology Key Laboratory, Wuhan Institute of Technology, Xiongchu Street, Wuhan 430073 (China); Chen, Rong, E-mail: rchenhku@hotmail.com [Key Laboratory for Green Chemical Process of Ministry of Education and Hubei Novel Reactor and Green Chemical Technology Key Laboratory, Wuhan Institute of Technology, Xiongchu Street, Wuhan 430073 (China)

    2014-01-15

    Antimony sulfide (Sb{sub 2}S{sub 3}) films were successfully prepared by spin coating Sb{sub 2}S{sub 3} micro-/nanorods with different sizes on glass slides, which was synthesized via a facile and rapid microwave irradiation method. The prepared Sb{sub 2}S{sub 3} micro-/nanorods and films were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and water contact angle (CA). The as-prepared Sb{sub 2}S{sub 3} films exhibited different surface wettabilities ranging from superhydrophilicity to superhydrophobicity, which was strongly dependent on the diameter of Sb{sub 2}S{sub 3} micro-/nanorod. Sb{sub 2}S{sub 3} film made by nanorods possessed superhydrophobic surface and high water adhesive property. After surface modification with stearic acid, the superhydrophobic surface exhibited an excellent self-cleaning property owing to its low adhesive force. The clarification of three possible states including Wenzel's state, “Gecko” state and Cassie's state for Sb{sub 2}S{sub 3} film surfaces was also proposed to provide a better understanding of interesting surface phenomena on Sb{sub 2}S{sub 3} films.

  9. Towards the chiral metabolomics: Liquid chromatography–mass spectrometry based DL-amino acid analysis after labeling with a new chiral reagent, (S)-2,5-dioxopyrrolidin-1-yl-1-(4,6-dimethoxy-1,3,5-triazin-2-yl) pyrrolidine-2-carboxylate, and the application to saliva of healthy volunteers

    Energy Technology Data Exchange (ETDEWEB)

    Mochizuki, Toshiki; Takayama, Takahiro; Todoroki, Kenichiro; Inoue, Koichi; Min, Jun Zhe; Toyo’oka, Toshimasa, E-mail: toyooka@u-shizuoka-ken.ac.jp

    2015-05-22

    Highlights: • A novel chiral labeling reagent was synthesized. • Analysis of DL-amino acids was performed by UPLC–ESI-MS/MS. • Efficient enantioseparation and detection of DL-amino acids were performed. • DL-Amino acid in saliva was successfully determined under mild conditions. - Abstract: A novel triazine-type chiral derivatization reagent, i.e., (S)-2,5-dioxopyrrolidin-1-yl-1-(4,6-dimethoxy-1,3,5-triazin-2-yl) pyrrolidine-2-carboxylate (DMT-(S)-Pro-OSu), was developed for the highly sensitive and selective detection of chiral amines and amino acids by UPLC–MS/MS analysis. The enantiomers of amino acids were easily labeled with the reagents at room temperature within 40 min in an alkaline medium containing triethylamine. The diastereomers derived from proteolytic amino acids, except serine, were well separated under isocratic elution conditions by reversed-phase chromatography using an ODS column (R{sub s} = 1.2–9.0). DL-Serine was separated by use of an ADME column which has relatively higher polar surface than the conventional ODS column. The characteristic product ions, i.e., m/z 195.3 and m/z 209.3, were detected from all the diastereomers by the collision-induced dissociation of the protonated molecule. A highly sensitive detection on the amol–fmol level was obtained from the selected reaction monitoring (SRM) chromatogram. The chiral amines (e.g., adrenaline and noradrenaline) labeled with DMT-(S)-Pro-OSu were also well separated and sensitively detected by the present procedure. The method using DMT-(S)-Pro-OSu was used for the determination of DL-amino acids in the human saliva from healthy volunteers. Various L-amino acids were identified in the saliva. Furthermore, D-alanine (D-Ala) and D-proline (D-Pro) were also detected in relatively high concentrations (>5%). The ratio was higher in male saliva than in female saliva. However, the difference in the ratio of D-Ala for one day was not very high and the effect of foods and beverage

  10. 4-({(Z-5-[(Z-3-Ethoxy-4-hydroxybenzylidene]-3-methyl-4-oxo-1,3-thiazolidin-2-ylidene}aminobenzoic acid dimethylformamide monosolvate

    Directory of Open Access Journals (Sweden)

    Paul Kosma

    2012-12-01

    Full Text Available The molecular structure of the title compound, C20H18N2O5S·C3H7NO, represents an essentially planar 5-benzylidene-thiazolidine moiety (r.m.s. deviation from planarity without ring substituents = 0.095 Å to which the 4-aminobenzoic acid fragment is inclined at 76.23 (1°. In the crystal, the benzoic acid molecules are arranged in layers parallel to [001] which are built up from inversion dimers held together by head-to-tail phenol–carboxy O—H...O hydrogen bonds and head-to-tail π–π stacking interactions between the 5-benzylidene-thiazolidine moieties (ring centroid distance = 3.579 Å. These layers are separated by the dimethylformamide solvent molecules which are firmly anchored via a short O—H...O hydrogen bond [O...O = 2.5529 (10 Å] donated by the –COOH group.

  11. Calculations of resonances parameters for the ((2s2) 1Se, (2s2p) 1,3P0) and ((3s2) 1Se, (3s3p) 1,3P0) doubly excited states of helium-like ions with Z≤10 using a complex rotation method implemented in Scilab

    Science.gov (United States)

    Gning, Youssou; Sow, Malick; Traoré, Alassane; Dieng, Matabara; Diakhate, Babacar; Biaye, Mamadi; Wagué, Ahmadou

    2015-01-01

    In the present work a special computational program Scilab (Scientific Laboratory) in the complex rotation method has been used to calculate resonance parameters of ((2s2) 1Se, (2s2p) 1,3P0) and ((3s2) 1Se, (3s3p) 1,3P0) states of helium-like ions with Z≤10. The purpose of this study required a mathematical development of the Hamiltonian applied to Hylleraas wave function for intrashell states, leading to analytical expressions which are carried out under Scilab computational program. Results are in compliance with recent theoretical calculations.

  12. Transition probabilities for the 3s2 3p(2P0)-3s3p2(4P) intersystem lines of Si II

    Science.gov (United States)

    Calamai, Anthony G.; Smith, Peter L.; Bergeson, S. D.

    1993-01-01

    Intensity ratios of lines of the spin-changing 'intersystem' multiplet of S II (4P yields 2P0) at 234 nm have been used to determine electron densities and temperatures in a variety of astrophysical environments. However, the accuracy of these diagnostic calculations have been limited by uncertainties associated with the available atomic data. We report the first laboratory measurement, using an ion-trapping technique, of the radiative lifetimes of the three metastable levels of the 3s3p2 4P term of Si II. Our results are 104 +/- 16, 406 +/- 33, and 811 +/- 77 micro-s for lifetimes of the J = 1/2, 5/2, and 3/2 levels, respectively. A-values were derived from our lifetimes by use of measured branching fractions. Our A-values, which differ from calculated values by 30 percent or more, should give better agreement between modeled and observed Si II line ratios.

  13. Development of atmospheric acid deposition in China from the 1990s to the 2010s

    International Nuclear Information System (INIS)

    Yu, Haili; He, Nianpeng; Wang, Qiufeng; Zhu, Jianxing; Gao, Yang; Zhang, Yunhai; Jia, Yanlong; Yu, Guirui

    2017-01-01

    Atmospheric acid deposition is a global environmental issue. China has been experiencing serious acid deposition, which is anticipated to become more severe with the country's economic development and increasing consumption of fossil fuels in recent decades. We explored the spatiotemporal variations of acid deposition (wet acid deposition) and its influencing factors by collecting nationwide data on pH and concentrations of sulfate (SO 4 2− ) and nitrate (NO 3 − ) in precipitation between 1980 and 2014 in China. Our results showed that average precipitation pH values were 4.59 and 4.70 in the 1990s and 2010s, respectively, suggesting that precipitation acid deposition in China has not seriously worsened. Average SO 4 2− deposition declined from 40.54 to 34.87 kg S ha −1 yr −1 but average NO 3 − deposition increased from 4.44 to 7.73 kg N ha −1 yr −1 . Specifically, the area of severe precipitation acid deposition in southern China has shrunk to some extent as a result of controlling the pollutant emissions; but the area of moderate precipitation acid deposition has expanded in northern China, associated with rapid industrial and transportation development. Furthermore, we found significant positive correlations between precipitation acid deposition, energy consumption, and rainfall. Our findings provide a relatively comprehensive evaluation of the spatiotemporal dynamics of precipitation acid deposition in China over past three decades, and confirm the idea that strategies implemented to save energy and control pollutant emissions in China have been effective in alleviating precipitation acid deposition. These findings might be used to demonstrate how developing countries could achieve economic development and environmental protection through the implementation of advanced technologies to reduce pollutant emissions. - Highlights: • Explore spatial and temporal dynamics of wet acid deposition during three decades in China. • Acid

  14. Hydrothermal synthesis of Fe2O3/graphene nanocomposite for selective determination of ascorbic acid in the presence of uric acid

    International Nuclear Information System (INIS)

    Yu, Zhiyuan; Li, Hejun; Lu, Jinhua; Zhang, Xinmeng; Liu, Ningkun; Zhang, Xu

    2015-01-01

    In this study, we had demonstrated a hydrothermal method to prepare Fe 2 O 3 /graphene (RG) nanocomposite for the determination of ascorbic acid (AA) in the presence of uric acid (UA). The synthesized materials were characterized by scanning electron microscopy (SEM), X-ray diffraction measurements (XRD), transmission electron microscopy (TEM) and inductively coupled plasma atomic emission spectrometry (ICP-AES). As a sensor, the Fe 2 O 3 /RG nanocomposite modified electrode exhibited synergistic effects which not only improved the electrochemical catalytic oxidation of AA, but also resolved the overlapping anodic peaks of AA and UA. And the results showed that Fe 2 O 3 /RG could be used for the determination of AA in the presence of low concentration of UA. Using the modified electrode with different concentrations of AA, the linear response range for the determination of AA in the presence UA was 0.57–3.97 mM (R = 0.9994). The detection limit (S/N = 3) was found to be 0.543 μM for the determination of AA. The results suggested that the Fe 2 O 3 /RG nanocomposite had the advantages of simplicity, high sensitivity and good selectivity for determination of AA

  15. Combinations of mutant FAD2 and FAD3 genes to produce high oleic acid and low linolenic acid soybean oil.

    Science.gov (United States)

    Pham, Anh-Tung; Shannon, J Grover; Bilyeu, Kristin D

    2012-08-01

    High oleic acid soybeans were produced by combining mutant FAD2-1A and FAD2-1B genes. Despite having a high oleic acid content, the linolenic acid content of these soybeans was in the range of 4-6 %, which may be high enough to cause oxidative instability of the oil. Therefore, a study was conducted to incorporate one or two mutant FAD3 genes into the high oleic acid background to further reduce the linolenic acid content. As a result, soybean lines with high oleic acid and low linolenic acid (HOLL) content were produced using different sources of mutant FAD2-1A genes. While oleic acid content of these HOLL lines was stable across two testing environments, the reduction of linolenic acid content varied depending on the number of mutant FAD3 genes combined with mutant FAD2-1 genes, on the severity of mutation in the FAD2-1A gene, and on the testing environment. Combination of two mutant FAD2-1 genes and one mutant FAD3 gene resulted in less than 2 % linolenic acid content in Portageville, Missouri (MO) while four mutant genes were needed to achieve the same linolenic acid in Columbia, MO. This study generated non-transgenic soybeans with the highest oleic acid content and lowest linolenic acid content reported to date, offering a unique alternative to produce a fatty acid profile similar to olive oil.

  16. Synthesis of 14C-labeled 3-{[1-ethoxycarbonyl-3-phenyl-(1S)-propyl]amino}-2,3,4,5-tetrahydro-2-oxo -1H-1-(3S)-benzazepine-1-acetic acid hydrochloride ([14C]CGS 14824A)

    International Nuclear Information System (INIS)

    Chaudhuri, N.K.; Patera, R.; Markus, B.; Mingsang Sung

    1987-01-01

    The title compound, CGS 14824A, was synthesized with a 14 C-label in the azepine ring in 14 steps starting with 1-bromo-3-phenylpropane (1) and K 14 CN in an overall yield of 1.31%. The reaction of 1 with K 14 CN yielded the nitrile 2 which upon hydrolysis followed by ring closure gave α-tetralone-1- 14 C (4). Bromination of 4 followed by oxime formation gave the bromo oxime 5, which upon Beckmann rearrangement by acid treatment yielded the ring expansion product 6. The bromine atom of 6 was then replaced by an azido group, and an acetic ester side chain was introduced at the nitrogen atom. Catalytic reduction of the azido compound 8 gave a mixture of epimeric amino esters which was resolved by salt formation with L-tartaric acid. The negatively rotating isomer was then reacted with 4-phenyl-2-oxo-butanoate in presence of sodium cyanoborohydride to give a mixture of diastereoisomers which were separated as their benzyl esters by chromatography. The major isomer was then converted to labeled CGS 14824A. (author)

  17. Calculations of resonances parameters for the ((2s2) 1Se, (2s2p) 1,3P0) and ((3s2) 1Se, (3s3p) 1,3P0) doubly excited states of helium-like ions with Z≤10 using a complex rotation method implemented in Scilab

    International Nuclear Information System (INIS)

    Gning, Youssou; Sow, Malick; Traoré, Alassane; Dieng, Matabara; Diakhate, Babacar; Biaye, Mamadi; Wagué, Ahmadou

    2015-01-01

    In the present work a special computational program Scilab (Scientific Laboratory) in the complex rotation method has been used to calculate resonance parameters of ((2s 2 ) 1 S e , (2s2p) 1,3 P 0 ) and ((3s 2 ) 1 S e , (3s3p) 1,3 P 0 ) states of helium-like ions with Z≤10. The purpose of this study required a mathematical development of the Hamiltonian applied to Hylleraas wave function for intrashell states, leading to analytical expressions which are carried out under Scilab computational program. Results are in compliance with recent theoretical calculations. - Highlights: • Resonance energy and widths computed for doubly excited states of helium-like ions. • Well-comparable results to the theoretical literature values up to Z=10. • Satisfactory agreements with theoretical calculations for widths

  18. Electron-impact excitation of multiply-charged ions using energy loss in merged beams: e + Si3+(3s2S1/2) → e + Si3+(3p2P1/2,3/2)

    International Nuclear Information System (INIS)

    Wahlin, E.K.; Thompson, J.S.; Dunn, G.H.; Phaneuf, R.A.; Gregory, D.C.; Smith, A.C.H.

    1990-01-01

    For the first time absolute total cross sections for electron-impact excitation of a multiply-charged ion have been measured using an electron-energy-loss technique. Measurements were made near threshold for the process e + Si 3+ (3s 2 S 1/2 ) → e + Si 3+ (3p 2 P 1/2 , 3/2 ) -- 8.88 eV. The 10 -15 cm 2 measured cross section agrees with results of 7-state close coupling calculations to better than the ±20% (90% CL) total uncertainty of the measurements. Convoluting the theoretical curve with a Gaussian energy distribution indicates an energy width of 0.15 approx-lt ΔE approx-lt 0.20 eV. 12 refs., 2 figs

  19. Thioglycolic acid-capped CuInS2/ZnS quantum dots as fluorescent probe for cobalt ion detection

    International Nuclear Information System (INIS)

    Zi, Lili; Huang, Yu; Yan, Zhengyu; Liao, Shenghua

    2014-01-01

    A novel sensing fluorescent probe based on the fluorescence quenching of the thioglycolic acid-capped CuInS 2 /ZnS quantum dots (CuInS 2 /ZnS/TGA QDs) was established for cobalt ions detection. The fluorescence quenching of CuInS 2 /ZnS/TGA QDs was due to the increasing surface deficiency and the inner-filter effect, which were attributed to the reaction between Co 2+ and sulfur bonds on the surface of QDs. The quenching curve could be fitted by a typical Stern–Volmer-type equation, with a linear relationship between the quenching efficiency and the concentration of cobalt ions in the range of 0.3012–90.36 μmol L −1 . And the detection limit (S/N=3) for Co 2+ was 0.16 μmol L −1 . Therefore, the established probe provided a simple, rapid, cheap and sensitive method for Co 2+ detection. In a word, this method can be used to detect Co 2+ in the environment. -- Highlights: • The CuInS2/ZnS QDs were used for the first time as a fluorescent probe for Co 2+ detection. • The dramatic color change could be observed when Co 2+ was added into the QDs solution. • The quenching of QDs was due to the increasing surface deficiency and the inner-filter effect. • This rapid, cheap and sensitive method was applied to the detection of Co 2+ in simulated water

  20. Synthesis, photostability and bioactivity of 2,3-cyclopropanated abscisic acid.

    Science.gov (United States)

    Wenjian, Liu; Xiaoqiang, Han; Yumei, Xiao; Jinlong, Fan; Yuanzhi, Zhang; Huizhe, Lu; Mingan, Wang; Zhaohai, Qin

    2013-12-01

    The plant hormone abscisic acid (ABA) plays a central role in the regulation of plant development and adaptation to environmental stress. The isomerization of ABA to the biologically inactive 2E-isomer by light considerably limits its applications in agricultural fields. To overcome this shortcoming, an ABA analogue, cis-2,3-cyclopropanated ABA, was synthesized, and its photostability and biological activities were investigated. This compound showed high photostability under UV light exposure, which was 4-fold higher than that of (±)-ABA. cis-2,3-cyclopropanated ABA exhibited high ABA-like activity, including the ability to effectively inhibit seed germination, seedling growth and stomatal movements of Arabidopsis. In some cases, its bioactivity approaches that of (±)-ABA. trans-2,3-cyclopropanated abscisic acid was also prepared, an isomer that was more photostable but which showed weak ABA-like activity. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  1. Rho Kinase ROCK2 Mediates Acid-Induced NADPH Oxidase NOX5-S Expression in Human Esophageal Adenocarcinoma Cells.

    Directory of Open Access Journals (Sweden)

    Jie Hong

    Full Text Available Mechanisms of the progression from Barrett's esophagus (BE to esophageal adenocarcinoma (EA are not fully understood. We have shown that NOX5-S may be involved in this progression. However, how acid upregulates NOX5-S is not well known. We found that acid-induced increase in NOX5-S expression was significantly decreased by the Rho kinase (ROCK inhibitor Y27632 in BE mucosal biopsies and FLO-1 EA cells. In addition, acid treatment significantly increased the Rho kinase activity in FLO-1 cells. The acid-induced increase in NOX5-S expression and H2O2 production was significantly decreased by knockdown of Rho kinase ROCK2, but not by knockdown of ROCK1. Conversely, the overexpression of the constitutively active ROCK2, but not the constitutively active ROCK1, significantly enhanced the NOX5-S expression and H2O2 production. Moreover, the acid-induced increase in Rho kinase activity and in NOX5-S mRNA expression was blocked by the removal of calcium in both FLO-1 and OE33 cells. The calcium ionophore A23187 significantly increased the Rho kinase activity and NOX5-S mRNA expression. We conclude that acid-induced increase in NOX5-S expression and H2O2 production may depend on the activation of ROCK2, but not ROCK1, in EA cells. The acid-induced activation of Rho kinase may be mediated by the intracellular calcium increase. It is possible that persistent acid reflux present in BE patients may increase the intracellular calcium, activate ROCK2 and thereby upregulate NOX5-S. High levels of reactive oxygen species derived from NOX5-S may cause DNA damage and thereby contribute to the progression from BE to EA.

  2. Local motifs in GeS{sub 2}–Ga{sub 2}S{sub 3} glasses

    Energy Technology Data Exchange (ETDEWEB)

    Pethes, I., E-mail: pethes.ildiko@wigner.mta.hu [Wigner Research Centre for Physics, Hungarian Academy of Sciences, H-1525 Budapest, P.O. 49 (Hungary); Nazabal, V.; Chahal, R.; Bureau, B. [Institut Sciences Chimiques de Rennes, UMR-CNRS 6226, Campus de Beaulieu, Université de Rennes 1, 35042 Rennes, Cedex (France); Kaban, I. [IFW Dresden, Institute for Complex Materials, Helmholtzstr. 20, 01069 Dresden (Germany); Belin, S. [Synchrotron SOLEIL, L' Orme des Merisiers, Saint Aubin, 91192 Gif sur Yvette (France); Jóvári, P. [Wigner Research Centre for Physics, Hungarian Academy of Sciences, H-1525 Budapest, P.O. 49 (Hungary)

    2016-07-15

    The structure of (GeS{sub 2}){sub 0.75}(Ga{sub 2}S{sub 3}){sub 0.25} and (GeS{sub 2}){sub 0.83}(Ga{sub 2}S{sub 3}){sub 0.17} glasses was investigated by Raman scattering, high energy X-ray diffraction and extended X-ray absorption fine structure (EXAFS) measurements at the Ga and Ge K-edges. The reverse Monte Carlo simulation technique (RMC) was used to obtain structural models compatible with diffraction and EXAFS datasets. It was found that the coordination number of Ga is close to four. While Ge atoms have only S neighbors, Ga binds to S as well as to Ga atoms showing a violation of chemical ordering in GeS{sub 2}–Ga{sub 2}S{sub 3} glasses. Analysis of the corner- and edge-sharing between [GeS{sub 4/2}] units revealed that about 30% of germanium atoms participate in the edge-shared tetrahedra. - Highlights: • Structural models of GeS{sub 2}–Ga{sub 2}S{sub 3} glasses consistent with XRD + EXAFS data are created. • Chemical order is respected but Ga–Ga bonds are present caused by S-deficiency. • The coordination number of Ga is 3.7 ± 0.3. • The frequency and geometry of corner/edge-sharing [GeS{sub 4/2}] units were determined.

  3. Thermochemical study of 2,5-dimethyl-3-furancarboxylic acid, 4,5-dimethyl-2-furaldehyde, and 3-acetyl-2,5-dimethylfuran

    International Nuclear Information System (INIS)

    Ribeiro da Silva, Manuel A.V.; Amaral, Luisa M.P.F.

    2011-01-01

    The standard (p o = 0.1 MPa) molar enthalpies of formation, in the gaseous state, at T = 298.15 K, for 2,5-dimethyl-3-furancarboxylic acid, 3-acetyl-2,5-dimethylfuran, and 4,5-dimethyl-2-furaldehyde were derived from the values of the standard molar enthalpies of formation, in the condensed phase, and the standard molar enthalpies of phase transition from the condensed to the gaseous state. The values of the standard molar enthalpies of formation of the compounds in the condensed phases were calculated from the measurements of the standard massic energies of combustion obtained by static bomb combustion calorimetry. The enthalpies of vaporization/sublimation were measured by Calvet high temperature microcalorimetry. For 2,5-dimethyl-3-furancarboxylic acid the standard enthalpy of sublimation was also calculated, by the application of the Clausius-Clapeyron equation, to the temperature dependence of the vapor pressures measured by the Knudsen effusion technique. (table)

  4. Temperature behaviour of optical parameters in (Ag3AsS3)0.3(As2S3)0.7 thin films

    Science.gov (United States)

    Kutsyk, Mykhailo M.; Ráti, Yosyp Y.; Izai, Vitalii Y.; Makauz, Ivan I.; Studenyak, Ihor P.; Kökényesi, Sandor; Komada, Paweł; Zhailaubayev, Yerkin; Smailov, Nurzhigit

    2015-12-01

    (Ag3AsS3)0.3(As2S3)0.7 thin films were deposited onto a quartz substrate by rapid thermal evaporation. The optical transmission spectra of thin films were measured in the temperature range 77-300 K. It is shown that the absorption edge spectra are described by the Urbach rule. The temperature behaviour of absorption spectra was studied, the temperature dependences of energy position of absorption edge and Urbach energy were investigated. The influence of transition from three-dimensional glass to the two-dimensional thin film as well as influence of Ag3AsS3 introduction into As2S3 on the optical parameters of (Ag3AsS3)0.3(As2S3)0.7 were analysed. The spectral and temperature behaviour or refractive index for (Ag3AsS3)0.3(As2S3)0.7 thin film were studied.

  5. Large-scale synthesis of double cauliflower-like Sb2S3 microcrystallines by hydrothermal method

    International Nuclear Information System (INIS)

    Wu, Lei; Xu, Hanyue; Han, Qiaofeng; Wang, Xin

    2013-01-01

    Highlights: •Highly uniform double cauliflower-like Sb 2 S 3 particles were synthesized via hydrothermal method. •Influence of reaction conditions on the morphology of the products was discussed. •Double cauliflower-like Sb 2 S 3 superstructures revealed broad spectrum response. -- Abstract: The double cauliflower-like Sb 2 S 3 superstructures assembled by nanorods were prepared using SbCl 3 and Na 2 S⋅9H 2 O as raw materials, dodecyltrimethylammonium bromide (DTAB, C 15 H 31 BrN) as surfactant under acidic condition at 180 °C for 30 h. The structure, morphology and composition of the product were characterized by X-ray diffraction pattern (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and energy diffraction spectroscopy (EDS). The effect of reaction conditions including temperature, reaction time and surfactants on the sample morphology was discussed and a possible mechanism for the formation of cauliflower-like Sb 2 S 3 was proposed. The cauliflower-like Sb 2 S 3 microcrystallines revealed broad spectrum response, which may have a good application prospect in solar energy utilization and photoelectric conversion fields

  6. Synthesis and Biological Activity of 2',3'-iso-Aryl-abscisic Acid Analogs.

    Science.gov (United States)

    Wan, Chuan; Wang, Mingan; Yang, Dongyan; Han, Xiaoqiang; Che, Chuanliang; Ding, Shanshan; Xiao, Yumei; Qin, Zhaohai

    2017-12-15

    2',3'- iso -Benzoabscisic acid ( iso -PhABA), an excellent selective abscisic acid (ABA) analog, was developed in our previous work. In order to find its more structure-activity information, some structural modifications were completed in this paper, including the substitution of phenyl ring and replacing the ring with heterocycles. Thus, 16 novel analogs of iso -PhABA were synthesized and screened with three bioassays, Arabidopsis and lettuce seed germination and rice seedling elongation. Some of them, i.e., 2',3'- iso -pyridoabscisic acid ( iso -PyABA) and 2',3'- iso -franoabscisic acid ( iso -FrABA), displayed good bioactivities that closed to iso -PhABA and natural (+)-ABA. Some others, for instance, substituted- iso -PhABA, exhibited certain selectivity to different physiological process when compared to iso -PhABA or (+)-ABA. These analogs not only provided new candidates of ABA-like synthetic plant growth regulators (PGRs) for practical application, but also new potential selective agonist/antagonist for probing the specific function of ABA receptors.

  7. N-(3-Chlorophenylmaleamic acid

    Directory of Open Access Journals (Sweden)

    B. Thimme Gowda

    2010-07-01

    Full Text Available In the title compound, C10H8ClNO3, the molecular conformation is stabilized by two intramolecular hydrogen bonds. The first is a short O—H...O hydrogen bond within the maleamic acid unit and the second is a C—H...O hydrogen bond which connects the amide group with the phenyl ring. The maleamic acid unit is essentially planar, with an r.m.s. deviation of 0.044 Å, and makes a dihedral angle of 15.2 (1° with the phenyl ring. In the crystal, intermolecular N—H...O hydrogen bonds link the molecules into C(7 chains running [010].

  8. Development of nitric oxide catalytic coatings by conjugating 3,3-disulfodipropionic acid and 3,3-diselenodipropionic acid for improving hemocompatibility.

    Science.gov (United States)

    Yang, Ying; Li, Yalong; Li, Xiangyang; Qi, Pengkai; Tu, Qiufen; Yang, Zhilu; Huang, Nan

    2015-12-02

    Nitric oxide (NO), discovered as an endothelium-derived relaxing factor, has been found to have multiple intracellular effects in vascular diseases including vasorelaxation regulation, endothelial regeneration, inhibition of leukocyte chemotaxis, and platelet activation. In the work described here, the authors have developed a NO-catalytic bioactive coating for improving hemocompatibility. The authors first prepared a dopamine and hexamethylendiamine (PDAM/HD) amine-rich adherent copolymer coating to introduce amine groups onto 316L stainless steel, followed by covalently conjugating 3,3-disulfodipropionic acid (S-S) and 3,3-diselenodipropionic acid (Se-Se), which mimic glutathione peroxidase-like catalytic production of NO. S-S and Se-Se were immobilized on the PDAM/HD surface via carbodiimide coupling chemistry. X-ray photoelectron spectroscopy analysis revealed clear S2p and Se3d signals, confirming the immobilization of S-S and Se-Se on the PDAM/HD surface. The NO release behavior of different samples was investigated. In detail, two species of thionitrites (RSNO), S-nitrosoglutathione (GSNO, endogenous NO donors) and S-nitrosoacetylpenicillamine (SNAP) were chosen as NO donors to investigate the NO catalytic properties of S-S and Se-Se modified PDAM/HD surfaces. Not only Se-Se@PDAM/HD but also S-S@PDAM/HD coatings showed the ability to continuously catalyze RSNO to generate NO in the presence of proper thiol reducing agent. For the Se-Se@PDAM/HD coating, the NO release amount and rate were greater than S-S@PDAM/HD in both GSNO and SNAP conditions. The results showed that organosulfide species possesses NO catalytic ability as well as organoselenium species. The authors demonstrated that both S-S@PDAM/HD and Se-Se@PDAM/HD coatings exhibited outstanding inhibition effect on platelet adhesion, aggregation and activation via the cyclic guanylate monophosphate signal pathway. Thus these results suggested that NO catalytic coatings based on organoselenium and

  9. Lineshape of Ne 1s photoionization satellite [1s2s]({sup 3}S)3s and its valence Auger decay spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Yarzhemsky, V.G.; Amusia, M.Ya.; Chernysheva, L.V

    2002-12-15

    Lineshape of Ne1s photoionization satellite [1s2s]({sup 3}S)3s({sup 2}S) and lineshapes of corresponding low-energy Auger spectra are calculated using the Many-Body Perturbation Theory. The results obtained reproduce the experimentally observed asymmetrical lineshape of photoelectron satellite and its intensity.

  10. Acides gras polyinsaturés trans : aspects métaboliques

    Directory of Open Access Journals (Sweden)

    Sebedio Jean-Louis

    2000-01-01

    Full Text Available Les acides gras trans polyinsaturés sont formés à partir des acides gras indispensables (acides linoléique et a-linolénique au cours des traitements technologiques comme par exemple le raffinage des huiles ou la friture [1, 2]. L’acide linolénique est plus sensible à l’isomérisation que l’acide linoléique. En effet, comme l’a montré Wolff dans une revue récente [3], le degré d’isomérisation de l’acide linolénique peut atteindre 30 à 35 %. On retrouve également ces pourcentages dans les formules infantiles et le lait de femme [1]. Les principaux isomères formés sont les composés monotrans, à savoir les 18 :2-9trans,12cis, 18 :2-9cis,12trans, 18 :3-9trans,12cis,15cis, et le 18 :3-9cis,12cis,15-trans. Cependant, une température de désodorisation supérieure à 220 °C entraîne la formation d’isomères di-trans [4]. À titre d’exemple, nous avons représenté dans le tableau le contenu de quelques huiles végétales en isomères des acides linoléique et a-linolénique. Compte tenu de leur présence dans l’alimentation, on peut s’interroger sur les conséquences nutritionnelles et biochimiques de leur ingestion.

  11. Metabolism of polyunsaturated (n-3) fatty acids by monkey seminal vesicles: isolation and biosynthesis of omega-3 epoxides.

    Science.gov (United States)

    Oliw, E H; Sprecher, H W

    1991-11-27

    Monooxygenases of monkey seminal vesicles can metabolize arachidonic acid (20:4(n-6)) by w3-hydroxylation to 18(R)-hydroxyeicosatetraenoic acid (18(R)-HETE) and eicosapentaenoic acid (20:5(n-3)) to 17,18-dihydroxyeicosatetraenoic acid (Oliw, E.H. (1989) J. Biol. Chem. 264, 17845-17853). The present study aimed to further characterize the oxygenation of (n-3) polyunsaturated fatty acids. 14C-Labelled 22:6(n-3), 20:5(n-3), 20:4-(n-3) and 18:3(n-3) were incubated with microsomes of seminal vesicles of the cynomolgus monkey, NADPH and a cyclooxygenase inhibitor, diclofenac, and the main metabolites were identified by capillary gas chromatography-mass spectrometry. 22:6(n-3) was slowly metabolized to 19,20-dihydroxy-4,7,10,13,16-docosapentaenoic acid, while 20:5(n-3), 20:4(n-3) and 18:3(n-3) were metabolized more efficiently to the corresponding w4,w3-diols. The w3 epoxides, which were obtained from 20:5(n-3) and 18:3(n-3), were isolated in the presence of an epoxide hydrolase inhibitor, 1(2)epoxy-3,3,3-trichloropropane, and the geometry of the epoxides was determined to be 17S, 18R and 15S, 16R, respectively. While 20:5(n-3) was metabolized almost exclusively to the epoxide and diol pair of metabolites, 18:3(n-3) was metabolized not only to the w3 epoxide and the corresponding diol, but also to the w2 alcohol, 17(R)-hydroxy-9,12,15-octadecatrienoic acid. 22:6(n-3) and 5,8,11,14-eicosatetraynoic acid inhibited the biosynthesis of 18(R)-HETE from arachidonic acid (IC50 0.16 and 0.14 mM, respectively). In comparison with 20:4 or 18:3(n-3), 18:1(n-9) and 22:5(n-6) appeared to be slowly metabolized by seminal monooxygenases, while 18:2(n-6) was converted to the w3 alcohol and to smaller amounts of the w2 alcohol (4:1). Together, the results indicate that the w3-hydroxylase and w3-epoxygenase enzyme(s) metabolize 20:4(n-6) and 20:5(n-3) almost exclusively to the w3(R) alcohol and the w3(R, S) epoxide, respectively, while longer and shorter fatty acids either are poor

  12. Elevated Plasma Levels of 3-Hydroxyisobutyric Acid Are Associated With Incident Type 2 Diabetes

    OpenAIRE

    Mardinoglu A; Gogg S; Lotta LA; Stancáková A; Nerstedt A; Boren J; Blüher M; Ferrannini E; Langenberg C; Wareham NJ; Laakso M; Smith U

    2018-01-01

    Branched-chain amino acids (BCAAs) metabolite, 3-Hydroxyisobutyric acid (3-HIB) has been identified as a secreted mediator of endothelial cell fatty acid transport and insulin resistance (IR) using animal models. To identify if 3-HIB is a marker of human IR and future risk of developing Type 2 diabetes (T2D), we measured plasma levels of 3-HIB and associated metabolites in around 10,000 extensively phenotyped individuals. The levels of 3-HIB were increased in obesity but not robustly associat...

  13. Synthesis and Biological Evaluation of (S)-Amino-2-methyl-4-[(76)Br]bromo-3-(E)-butenoic Acid (BrVAIB) for Brain Tumor Imaging.

    Science.gov (United States)

    Burkemper, Jennifer L; Huang, Chaofeng; Li, Aixiao; Yuan, Liya; Rich, Keith; McConathy, Jonathan; Lapi, Suzanne E

    2015-11-12

    The novel compound, (S)-amino-2-methyl-4-[(76)Br]bromo-3-(E)-butenoic acid (BrVAIB, [(76)Br]5), was characterized against the known system A tracer, IVAIB ([(123)I]8). [(76)Br]5 was prepared in a 51% ± 19% radiochemical yield with high radiochemical purity (≥98%). The biological properties of [(76)Br]5 were compared with those of [(123)I]8. Results showed that [(76)Br]5 undergoes mixed amino acid transport by system A and system L transport, while [(123)I]8 had less uptake by system L. [(76)Br]5 demonstrated higher uptake than [(123)I]8 in DBT tumors 1 h after injection (3.7 ± 0.4% ID/g vs 1.5 ± 0.3% ID/g) and also showed higher uptake vs [(123)I]8 in normal brain. Small animal PET studies with [(76)Br]5 demonstrated good tumor visualization of intracranial DBTs up to 24 h with clearance from normal tissues. These results indicate that [(76)Br]5 is a promising PET tracer for brain tumor imaging and lead compound for a mixed system A and system L transport substrate.

  14. Evaluation of model parameters for growth, tannic acid utilization and tannase production in Bacillus gottheilii M2S2 using polyurethane foam blocks as support.

    Science.gov (United States)

    Selvaraj, Subbalaxmi; Vytla, Ramachandra Murty

    2017-10-01

    Production of tannase from B. gottheilii M2S2 was studied under solid-state fermentation with an optimized medium consisting of polyurethane foam matrix of dimension 40 × 40 × 5 mm, impregnated with a liquid medium comprising (w/v): 4% tannic acid; 2% NH 4 NO 3 ; 0.1% KH 2 PO 4 ; 0.2% MgSO 4 ; 0.1% NaCl and 0.05% CaCl 2 ·2H 2 O in distilled water, having a pH of 4.7. Maximum tannase production of 56.87 U/L was obtained after 32 h of fermentation at 32 °C in static condition. This study deals with the evaluation of unstructured kinetic models to understand the behavior of biomass, tannase production and tannic acid degradation, with the fermentation time. The growth rate of B. gottheilii M2S2 was 0.0703 h -1 at 32 h of fermentation. Product ( Y x/s ) and biomass yield ( Y p/s ) coefficients were estimated as 1.77 U/g of tannic acid and 0.276 g of biomass/g of tannic acid. All the kinetic constants µ , α , β , m and n were evaluated using MATLAB 2015Rb program. The experimental and model-generated data showed a good correlation, which indicated that these models will describe tannase production and fermentation process.

  15. Carcinogenic 3-nitrobenzanthrone but not 2-nitrobenzanthrone is metabolised to an unusual mercapturic acid in rats.

    Science.gov (United States)

    Linhart, Igor; Mráz, Jaroslav; Hanzlíková, Iveta; Silhánková, Alexandra; Frantík, Emil; Himl, Michal

    2012-02-05

    3-Nitrobenzanthrone (3-NBA) is an extremely potent mutagen and suspect human carcinogen found in diesel exhaust. Its isomer 2-nitrobenzanthrone (2-NBA) has also been found in ambient air. These isomers differ in mutagenicity in Salmonella by 2-3 orders of magnitude. To identify their urinary metabolites and also to assess the assumed differences in their excretion, rats were dosed orally with 2mg/kg b.w. of either 2-NBA or 3-NBA. Their urine was collected for two consecutive days after dosage. Both LC-ESI-MS and GC-MS confirmed formation of the corresponding aminobenzanthrones (ABA). Excretion of these metabolites within the first day after dosing with 2- and 3-ABA amounted to 0.32±0.06 and 0.83±0.40% of the doses, respectively, while the excretion within the second day was by one order of magnitude lower. A novel mercapturic acid metabolite of 3-NBA was identified in urine by LC-ESI-MS as N-acetyl-S-(3-aminobenzanthron-2-yl)cysteine (3-ABA-MA) by comparison with the authentic standard. Its excretion amounted to 0.49±0.15 and 0.02±0.01% of dose within the first and second day after dosing, respectively. In contrast, no mercapturic acid was detected in the urine of rats dosed with 2-NBA. Observed difference in the mercapturic acid formation between 2- and 3-NBA is a new distinctive feature reflecting differences in the critical step of their metabolism, i.e., benzanthronylnitrenium ion formation that is intrinsically associated with biological activities of these two isomers. Moreover, 3-ABA-MA is a promising candidate biomarker of exposure to the carcinogenic 3-NBA. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  16. Synthesis of (R,S)-[2,3-13C2]-1-(1'-methyl-2'-pyrrolidinyl)propan-2-one; {(R,S)-[2',3'-13C2]hygrinePound right bracePound

    International Nuclear Information System (INIS)

    Abraham, T.W.; Leete, Edward

    1996-01-01

    2-Ethoxy-1-methyl-5-pyrrolidinone (1) was reacted with ethyl [3,4- 13 C 2 ]-acetoacetate (2) in the presence of TiCl 4 to give ethyl [3,4- 13 C 2 ]-2-(1'-methyl-5'-oxo-2'-pyrrolidinyl)-3-oxobutanoate (3) in 85% yield. Decarboethoxylation of ethyl [3,4- 13 C 2 ]-2-(1'-methyl-5'-oxo-2'-pyrrolidinyl)-3-oxobutan-oate (3) was accomplished using NaCl and H 2 O in DMSO to give (R,S)-[2,3- 13 C 2 ]-1-(1'-methyl-5'-oxo-2'-pyrrolidinyl)propan-2-o ne (4) in 91% yield. Protection of the ketone as a ketal (ethylene glycol, H + ), followed by reduction of the amide to the amine using LiAlH 4 and subsequent deprotection of the ketal gave (R,S)-[2,3- 13 C 2 ]-1-(1'-methyl-2'-pyrrolidinyl)propan-2-one ((R,s)-[2', 3'- 13 C 2 ]Hygrine) (8) in 78% yield. (61% overall yield from ethyl [3,4- 13 C 2 ]acetoacetate). (Author)

  17. Voltammetric Determination of Tumor Biomarkers for Neuroblastoma (Homovanillic Acid, Vanillylmandelic Acid, and 5-Hydroxyindole-3-acetic Acid) at Screen-printed Carbon Electrodes

    Czech Academy of Sciences Publication Activity Database

    Makrlíková, Anna; Ktena, E.; Economou, A.; Fischer, J.; Navrátil, Tomáš; Barek, J.; Vyskočil, V.

    2017-01-01

    Roč. 29, č. 1 (2017), s. 146-153 ISSN 1040-0397 Institutional support: RVO:61388955 Keywords : Homovanillic acid * Vanillylmandelic acid * 5-Hydroxyindole-3-acetic acid Subject RIV: CG - Electrochemistry OBOR OECD: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis) Impact factor: 2.851, year: 2016

  18. A new structural class of subtype-selective inhibitor of cloned excitatory amino acid transporter, EAAT2

    DEFF Research Database (Denmark)

    Bräuner-Osborne, Hans; Hermit, M B; Nielsen, B

    2000-01-01

    We have studied the pharmacological effects of (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) and the enantiomers of (RS)-2-amino-3-(3-hydroxy-1,2, 5-thiadiazol-4-yl)propionic acid (TDPA) on cloned human excitatory amino acid transporter subtypes 1, 2 and 3 (EAAT1......-3) expressed in Cos-7 cells. Whereas AMPA and (R)-TDPA were both inactive as inhibitors of [3H]-(R)-aspartic acid uptake on all three EAAT subtypes, (S)-TDPA was shown to selectively inhibit uptake by EAAT2 with a potency equal to that of the endogenous ligand (S)-glutamic acid. (S)-TDPA thus represents a new...

  19. Controlled synthesis of novel 3D dendritic Bi2S3 /cross-linked poly(vinyl alcohol) nanocomposites

    International Nuclear Information System (INIS)

    Wu, W-T; Shi Lei; Pang Wenmin; Wang Yusong; Zhu Qingren; Xu Guoyong

    2006-01-01

    Novel spherical three-dimensional (3D) dendritic Bi 2 S 3 /cross-linked poly(vinyl alcohol) (PVA) nanocomposites were successfully synthesized in aqueous solution of amphiphilic polyvinylacetone (PVKA) (ketalization degree D H = 0.549), via one-step in situ decomposition of the complex [Bi(Tu) x ] 3+ under γ-ray irradiation, utilizing the controllable hydrolysis property of PVKA in acidic solution. Herein, PVA chains are obtained from the hydrolysed PVKA. These uniform 3D spherical nanocomposites have a structure similar to that found in the natural lotus leaf, where every microscale papilla on the leaf surface is covered by nanoscale papillae

  20. Synthesis, physical and chemical properties of 2-((5-(hydroxy(phenylmethyl-4R-4H-1,2,4-triazole-3-ylthioacetic acids and its salts

    Directory of Open Access Journals (Sweden)

    A. M. Rud

    2018-02-01

    Full Text Available Today’s a creation of new domestic medicines is very important problem for pharmacy and medicine. Therefore, it is relevant to synthesize new domestic biologically active compounds. It is known that a large number of new 3-thio and 4-amino derivatives on the basis of 1,2,4-triazole have recently been synthesized, among which compounds with high pharmacological activity have been found. Based on the experience of previous studies and with the aim of creating new original drugs, our goal was to synthesize 2-((5-(hydroxy(phenylmethyl-4-R-4H-1,2,4-triazole-3-ylthioacetic acids series and to obtain salts on its basis, which have high indicators of pharmacological activity based on the literature data. The goal of the work is a targeted synthesis of potential low-toxic and highly effective compounds with a wide spectrum of pharmacological activity among 5-(hydroxy(phenylmethyl-4-R-4H-1,2,4-triazole-3-thione derivatives, confirmation of their individuality and structure, as well as the study of physical-chemical properties, for the further pharmacological screening. Materials and methods. 2-((5-(hydroxy(phenylmethyl-4-R-4H-1,2,4-triazole-3-ylthioacetic acids were prepared by heating 5- (hydroxy(phenylmethyl-4-R-4H-1,2,4-triazol-3-thiones with chloroacetic acid. Subsequently, the synthesized thioacetic acids were subject for modification. Salts of 2-((5-(hydroxy(phenylmethyl-4-R-4H-1,2,4-triazole-3-ylthioacetic acids were obtained by reacting thioacetic acids with equivalents of sodium or potassium hydroxides. To obtain Iron(II, Copper(II or Zinc(II salts, half-molar amounts of the appropriate sulfates were added to the obtained solutions. Salts of 2-((5-(hydroxy(phenylmethyl-4-R-4H-1,2,4-triazole-3-ylthioacetic acids with organic bases were obtained by the reaction of acids with piperidine or morpholine in ethanol medium. Results. During the synthetic studies, 13 previously undescribed new compounds were obtained. The individuality of 2-((5-(hydroxy

  1. Characterisation of (R-2-(2-Fluorobiphenyl-4-yl-N-(3-Methylpyridin-2-ylPropanamide as a Dual Fatty Acid Amide Hydrolase: Cyclooxygenase Inhibitor.

    Directory of Open Access Journals (Sweden)

    Sandra Gouveia-Figueira

    Full Text Available Increased endocannabinoid tonus by dual-action fatty acid amide hydrolase (FAAH and substrate selective cyclooxygenase (COX-2 inhibitors is a promising approach for pain-relief. One such compound with this profile is 2-(2-fluorobiphenyl-4-yl-N-(3-methylpyridin-2-ylpropanamide (Flu-AM1. These activities are shown by Flu-AM1 racemate, but it is not known whether its two single enantiomers behave differently, as is the case towards COX-2 for the parent flurbiprofen enantiomers. Further, the effects of the compound upon COX-2-derived lipids in intact cells are not known.COX inhibition was determined using an oxygraphic method with arachidonic acid and 2-arachidonoylglycerol (2-AG as substrates. FAAH was assayed in mouse brain homogenates using anandamide (AEA as substrate. Lipidomic analysis was conducted in unstimulated and lipopolysaccharide + interferon γ- stimulated RAW 264.7 macrophage cells. Both enantiomers inhibited COX-2 in a substrate-selective and time-dependent manner, with IC50 values in the absence of a preincubation phase of: (R-Flu-AM1, COX-1 (arachidonic acid 6 μM; COX-2 (arachidonic acid 20 μM; COX-2 (2-AG 1 μM; (S-Flu-AM1, COX-1 (arachidonic acid 3 μM; COX-2 (arachidonic acid 10 μM; COX-2 (2-AG 0.7 μM. The compounds showed no enantiomeric selectivity in their FAAH inhibitory properties. (R-Flu-AM1 (10 μM greatly inhibited the production of prostaglandin D2 and E2 in both unstimulated and lipopolysaccharide + interferon γ- stimulated RAW 264.7 macrophage cells. Levels of 2-AG were not affected either by (R-Flu-AM1 or by 10 μM flurbiprofen, either alone or in combination with the FAAH inhibitor URB597 (1 μM.Both enantiomers of Flu-AM1 are more potent inhibitors of 2-AG compared to arachidonic acid oxygenation by COX-2. Inhibition of COX in lipopolysaccharide + interferon γ- stimulated RAW 264.7 cells is insufficient to affect 2-AG levels despite the large induction of COX-2 produced by this treatment.

  2. New compounds bearing [M(S_2O_7)_3]"2"- anions (M = Si, Ge, Sn): Syntheses and characterization of A_2[Si(S_2O_7)_3] (A = Na, K, Rb), A_2[Ge(S_2O_7)_3] (A = Li, Na, K, Rb, Cs), A_2[Sn(S_2O_7)_3] (A = Na, K), and the unique germanate Hg_2[Ge(S_2O_7)_3]Cl_2 with cationic "1_∞[HgCl_2_/_2]"+ chains

    International Nuclear Information System (INIS)

    Logemann, Christian; Witt, Julia; Wickleder, Mathias S.; Gunzelmann, Daniel; Senker, Juergen

    2012-01-01

    The reaction of the group 14 tetrachlorides MCl_4 (M = Si, Ge, Sn) with oleum (65 % SO_3) at elevated temperatures led to the unique anionic complexes [M(S_2O_7)_3]"2"- that show the central M atoms in coordination of three chelating S_2O_7"2"- groups. The mean distances M-O within the complexes increase from 175 pm (M = Si) via 186 pm (M = Ge) up to 200 pm (M = Sn). The charge balance for the [M(S_2O_7)_3]"2"- anions is achieved by alkaline metal ions A"+ (A = Li, Na, K, Rb, Cs) which were implemented in the syntheses in form of their sulfates. The size of the A"+ ions, i.e. their coordination requirement causes the crystallographic differences in the crystal structures, while the structure of the complex [M(S_2O_7)_3]"2"- anions remains essentially unaffected. Furthermore, we were able to characterize the unique germanate Hg_2[Ge(S_2O_7)_3]Cl_2 which forms when HgCl_2 is added as a source for the counter cation. The Hg"2"+ and the Cl"- ions form infinite cationic chains according to "1_∞[HgCl_2_/_2]"+ which take care for the charge compensation. For selected examples of the compounds the thermal behavior has been monitored by means of thermal analyses and X-ray powder diffraction. For A being an alkaline metal the decomposition product is a mixture of the sulfates A_2SO_4 and the dioxides MO_2, whereas Hg_2[Ge(S_2O_7)_3]Cl_2 shows a more complicated decomposition. The tris-(disulfato)-silicate Na_2[Si(S_2O_7)_3] has additionally been examined by solid state "2"9Si and "2"3Na NMR spectroscopic measurements. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Chemically deposited In2S3–Ag2S layers to obtain AgInS2 thin films by thermal annealing

    International Nuclear Information System (INIS)

    Lugo, S.; Peña, Y.; Calixto-Rodriguez, M.; López-Mata, C.; Ramón, M.L.; Gómez, I.; Acosta, A.

    2012-01-01

    Highlights: ► We obtained polycrystalline silver indium sulfide thin films through the annealing of chemically deposited In 2 S 3 –Ag 2 S films. ► According to XRD chalcopyrite structure of AgInS 2 was obtained. ► AgInS 2 thin film has a band gap of 1.86 eV and a conductivity value of 1.2 × 10 −3 (Ω cm) −1 . - Abstract: AgInS 2 thin films were obtained by the annealing of chemical bath deposited In 2 S 3 –Ag 2 S layers at 400 °C in N 2 for 1 h. According to the XRD and EDX results the chalcopyrite structure of AgInS 2 has been obtained. These films have an optical band gap, E g , of 1.86 eV and an electrical conductivity value of 1.2 × 10 −3 (Ω cm) −1 .

  4. Luminescence of Y2O2S-Eu3+ and Ln2O2S-Tb3+ films grown by the method of photostimulated epitaxy

    International Nuclear Information System (INIS)

    Maksimovskij, S.N.; Sidorov, P.P.; Sluch, M.I.

    1990-01-01

    Study of luminescence of Y 2 O 2 S-Eu 3+ (1) and La 2 O 2 S-Tb 3+ (2) films, grown from vapor phase by photostimulated epitaxy method is carried out. Spectroscopic analysis data showed that films(1) spectra contain narrow lines, relating to C 3V symmetry centre, and wider lines, relating to C S symmetry centre. Films(2) possess intensive luminescence in green spectral region, but luminescence lines are wider due to higher number of defects. As to production of film luminescent screens the method is shown to be promising

  5. Structure and optical properties of thin As{sub 2}S{sub 3}-In{sub 2}S{sub 3} films

    Energy Technology Data Exchange (ETDEWEB)

    Todorov, R; Pirov, J; Petkov, K [Institute of Optical Materials and Technologies ' Acad. J. Malinowski' , Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl.109, 1113 Sofia (Bulgaria); Tsankov, D, E-mail: rossen@clf.bas.bg [Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev St. bl.9, 1113 Sofia (Bulgaria)

    2011-08-03

    This paper deals with the optical properties of thin As{sub 2}S{sub 3}-In{sub 2}S{sub 3} films. The thin layers were deposited by thermal co-evaporation of As{sub 2}S{sub 3} and In{sub 2}S{sub 3}. The composition of the coatings was controlled by x-ray microanalysis; it was found to be close to the expected one. The refractive index n and optical band gap E{sub g}{sup opt} were calculated from the transmittance and reflectance spectra. The results showed that the refractive index of thin As-S films is not affected by the addition of 1 at% indium and it increases from 2.46 to 2.58 for thin film with 13 at% In. A decrease in the changes in the refractive index, {Delta}n, after exposure to light or annealing with addition of indium in arsenic sulfide is observed. To explain the influence of the indium on the photoinduced changes in the optical properties of thin As-S-In films, the glass structure was investigated by infrared spectroscopy. The calculated values of the optical constants were compared with those obtained from ellipsometric measurements.

  6. 2-Chloro-1,3-propanediol (2-MCPD) and its fatty acid esters: cytotoxicity, metabolism, and transport by human intestinal Caco-2 cells.

    Science.gov (United States)

    Buhrke, Thorsten; Frenzel, Falko; Kuhlmann, Jan; Lampen, Alfonso

    2015-12-01

    The food contaminants 3-chloro-1,2-propanediol (3-MCPD) and 3-MCPD fatty acid esters have attracted considerable attention in the past few years due to their toxic properties and their occurrence in numerous foods. Recently, significant amounts of the isomeric compounds 2-chloro-1,3-propanediol (2-MCPD) fatty acid esters have been detected in refined oils. Beside the interrogation which toxic effects might be related to the core compound 2-MCPD, the key question from the risk assessment perspective is again-as it was discussed for 3-MCPD fatty acid esters before-to which degree these esters are hydrolyzed in the gut, thereby releasing free 2-MCPD. Here, we show that free 2-MCPD but not 2-MCPD fatty acid esters were able to cross a monolayer of differentiated Caco-2 cells as an in vitro model for the human intestinal barrier. Instead, the esters were hydrolyzed by the cells, thereby releasing free 2-MCPD which was neither absorbed nor metabolized by the cells. Cytotoxicity assays revealed that free 2-MCPD as well as free 3-MCPD was not toxic to Caco-2 cells up to a level of 1 mM, whereas cellular viability was slightly decreased in the presence of a few 2-MCPD and 3-MCPD fatty acid esters at concentrations above 10 µM. The observed cytotoxic effects correlated well with the induction of caspase activity and might be attributed to the induction of apoptosis by free fatty acids which were released from the esters in the presence of Caco-2 cells.

  7. Combined intervention with pioglitazone and n-3 fatty acids in metformin-treated type 2 diabetic patients: improvement of lipid metabolism

    Czech Academy of Sciences Publication Activity Database

    Veleba, J.; Kopecký Jr., J.; Janovská, Petra; Kuda, Ondřej; Horáková, Olga; Malínská, H.; Kazdová, L.; Oliyarnyk, O.; Škop, V.; Trnovská, J.; Hájek, M.; Škoch, A.; Flachs, Pavel; Bardová, Kristina; Rossmeisl, Martin; Olza, J.; de Castro, S. G.; Calder, P. C.; Gardlo, Alžběta; Fišerová, E.; Jensen, J.; Bryhn, M.; Kopecký, Jan; Pelikánová, T.

    2015-01-01

    Roč. 12, Dec 2 (2015), s. 52 ISSN 1743-7075 R&D Projects: GA MZd(CZ) NT13763 Institutional support: RVO:67985823 Keywords : eicosapentaenoic acid * docosahexaenoic acid * indirect calorimetry * meal test * humans * hyperinsulinemic-euglycemic clamp Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 3.280, year: 2015

  8. Elevated Plasma Levels of 3-Hydroxyisobutyric Acid Are Associated With Incident Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Adil Mardinoglu

    2018-01-01

    Full Text Available Branched-chain amino acids (BCAAs metabolite, 3-Hydroxyisobutyric acid (3-HIB has been identified as a secreted mediator of endothelial cell fatty acid transport and insulin resistance (IR using animal models. To identify if 3-HIB is a marker of human IR and future risk of developing Type 2 diabetes (T2D, we measured plasma levels of 3-HIB and associated metabolites in around 10,000 extensively phenotyped individuals. The levels of 3-HIB were increased in obesity but not robustly associated with degree of IR after adjusting for BMI. Nevertheless, also after adjusting for obesity and plasma BCAA, 3-HIB levels were associated with future risk of incident T2D. We also examined the effect of 3-HIB on fatty acid uptake in human cells and found that both HUVEC and human cardiac endothelial cells respond to 3-HIB whereas human adipose tissue-derived endothelial cells do not respond to 3-HIB. In conclusion, we found that increased plasma level of 3-HIB is a marker of future risk of T2D and 3-HIB may be important for the regulation of metabolic flexibility in heart and muscles.

  9. Crystal structure of (1S,3R,8R,9R-2,2-dichloro-3,7,7-trimethyl-10-methylenetricyclo[6.4.0.01,3]dodecan-9-ol

    Directory of Open Access Journals (Sweden)

    Ahmed Benzalim

    2016-08-01

    Full Text Available The title compound, C16H24Cl2O, was synthesized by treating (1S,3R,8S,9R,10S-2,2-dichloro-3,7,7,10-tetramethyl-9,10-epoxytricyclo[6.4.0.01,3]dodecane with a concentrated solution of hydrobromic acid. It is built up from three fused rings: a cycloheptane ring, a cyclohexyl ring bearing alkene and hydroxy substituents, and a cyclopropane ring bearing two chlorine atoms. The asymmetric unit contains two molecules linked by an O—H...O hydrogen bond. In the crystal, further O—H...O hydrogen bonds build up an R44(8 cyclic tetramer. One of the molecules presents disorder that affects the seven-membered ring. In both molecules, the six-membered rings display a chair conformation, whereas the seven-membered rings display conformations intermediate between boat and twist-boat for the non-disordered molecule and either a chair or boat and twist-boat for the disordered molecule owing to the disorder. The absolute configuration for both molecules is 1S,3R,8R,9R and was deduced from the chemical pathway and further confirmed by the X-ray structural analysis.

  10. (S,Z-3-Phenyl-2-[(1,1,1-trichloro-7-methoxy-2,7-dioxohept-3-en-4-ylamino]propanoic acid monohydrate

    Directory of Open Access Journals (Sweden)

    Alex Fabiani Claro Flores

    2014-02-01

    Full Text Available In the title compound, C17H18Cl3NO5·H2O, intramolecular N—H...O and C—H...Cl hydrogen bonds form S(6 and S(5 ring motifs, respectively. The chiral organic molecule is connected to the solvent water molecule by a short O—H...O hydrogen bond. In the crystal, a weak C—H...Cl interaction connects the organic molecules along [100] while the water molecules act as bridges between the organic molecules in both the [100] and [010] directions, generating layers parallel to the ab plane.

  11. 2s 2p 3P10 → 2s21S0 intercombination line in beryllium-like krypton, molybdenum and tungsten

    International Nuclear Information System (INIS)

    Glass, R.

    1979-01-01

    Transition probabilities are evaluated for the 2s 2p 3 P 1 0 → 2s 2 1 S 0 transition in beryllium-like ions for krypton, molybdenum and tungsten, using configuration-interaction wavefunctions. The importance of the 2s 3p 1 P 1 0 configuration is considered

  12. Dimethyl 2,2′-[Carbonylbis(azanediyl](2S,2S-bis[3-(4-hydroxyphenylpropanoate

    Directory of Open Access Journals (Sweden)

    Raffaella Mancuso

    2018-02-01

    Full Text Available The thus-far unknown ureic derivative dimethyl 2,2′-[carbonylbis(azanediyl](2S,2S-bis[3-(4-hydroxyphenylpropanoate] has been efficiently synthesized by enantiospecific oxidative carbonylation of readily available l-tyrosine methyl ester, using a very simple catalytic system (PdI2 in conjunction with KI under relatively mild conditions (100 °C for 5 h in DME as the solvent and under 20 atm of a 4:1 mixture CO-air.

  13. Formic Acid Modified Co3O4-CeO2 Catalysts for CO Oxidation

    Directory of Open Access Journals (Sweden)

    Ruishu Shang

    2016-03-01

    Full Text Available A formic acid modified catalyst, Co3O4-CeO2, was prepared via facile urea-hydrothermal method and applied in CO oxidation. The Co3O4-CeO2-0.5 catalyst, treated by formic acid at 0.5 mol/L, performed better in CO oxidation with T50 obtained at 69.5 °C and T100 obtained at 150 °C, respectively. The characterization results indicate that after treating with formic acid, there is a more porous structure within the Co3O4-CeO2 catalyst; meanwhile, despite of the slightly decreased content of Co, there are more adsorption sites exposed by acid treatment, as suggested by CO-TPD and H2-TPD, which explains the improvement of catalytic performance.

  14. 15-Lipoxygenase metabolites of α-linolenic acid, [13-(S)-HPOTrE and 13-(S)-HOTrE], mediate anti-inflammatory effects by inactivating NLRP3 inflammasome

    Science.gov (United States)

    Kumar, Naresh; Gupta, Geetika; Anilkumar, Kotha; Fatima, Naireen; Karnati, Roy; Reddy, Gorla Venkateswara; Giri, Priyanka Voori; Reddanna, Pallu

    2016-01-01

    The ratio of ω-6 to ω-3 polyunsaturated fatty acids (PUFAs) appears to be critical in the regulation of various pathophysiological processes and to maintain cellular homeostasis. While a high proportion of dietary intake of ω-6 PUFAs is associated with various inflammatory disorders, higher intake of ω-3 PUFAs is known to offer protection. It is now well established that beneficial effects of ω-3 PUFAs are mediated in part by their oxygenated metabolites mainly via the lipoxygenase (LOX) and cyclooxygenase (COX) pathways. However, the down-stream signaling pathways that are involved in these anti-inflammatory effects of ω-3 PUFAs have not been elucidated. The present study evaluates the effects of 15-LOX metabolites of α-linolenic acid (ALA, ω-3 PUFA) on lipopolysaccharide (LPS) induced inflammation in RAW 264.7 cells and peritoneal macrophages. Further, the effect of these metabolites on the survival of BALB/c mice in LPS mediated septic shock and also polymicrobial sepsis in Cecal Ligation and Puncture (CLP) mouse model was studied. These studies reveal the anti-inflammatory effects of 13-(S)-hydroperoxyoctadecatrienoic acid [13-(S)-HPOTrE] and 13-(S)-hydroxyoctadecatrienoic acid [13-(S)-HOTrE] by inactivating NLRP3 inflammasome complex through the PPAR-γ pathway. Additionally, both metabolites also deactivated autophagy and induced apoptosis. In mediating all these effects 13-(S)-HPOTrE was more potent than 13-(S)-HOTrE. PMID:27535180

  15. Electrical conductivity studies in (Ag3AsS3)x(As2S3)1-x superionic glasses and composites

    Science.gov (United States)

    Studenyak, I. P.; Neimet, Yu. Yu.; Kranjčec, M.; Solomon, A. M.; Orliukas, A. F.; Kežionis, A.; Kazakevičius, E.; Šalkus, T.

    2014-01-01

    Compositional, frequency, and temperature studies of impedance and electrical conductivity in (Ag3AsS3)x(As2S3)1-x superionic glasses and composites were performed. Frequency range from 10 Hz to 3 × 109 Hz and temperature interval 300-400 K were used for the measurements. Compositional dependences of electrical conductivity and activation energy are analyzed; the most substantial changes are observed with the transition from (Ag3AsS3)0.4(As2S3)0.6 glass to (Ag3AsS3)0.5(As2S3)0.5 composite. With increase of Ag3AsS3 content, the investigated materials are found to have crystalline inclusions and show the two-phase composite nature. Addition of Ag3AsS3 leads to the increase of electrical conductivity whereas the activation energy decreases.

  16. Thioglycolic acid-capped CuInS{sub 2}/ZnS quantum dots as fluorescent probe for cobalt ion detection

    Energy Technology Data Exchange (ETDEWEB)

    Zi, Lili; Huang, Yu [Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, 4 Tongjia Lane, Gulou District, Nanjing 210009 (China); Department of Analytical Chemistry, China Pharmaceutical University, 24 Tongjia Lane, Gulou District, Nanjing 210009 (China); Yan, Zhengyu, E-mail: yanzhengyujiang@126.com [Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, 4 Tongjia Lane, Gulou District, Nanjing 210009 (China); Department of Analytical Chemistry, China Pharmaceutical University, 24 Tongjia Lane, Gulou District, Nanjing 210009 (China); Liao, Shenghua, E-mail: liaoshenghuacpu@hotmail.com [Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, 4 Tongjia Lane, Gulou District, Nanjing 210009 (China); Department of Analytical Chemistry, China Pharmaceutical University, 24 Tongjia Lane, Gulou District, Nanjing 210009 (China)

    2014-04-15

    A novel sensing fluorescent probe based on the fluorescence quenching of the thioglycolic acid-capped CuInS{sub 2}/ZnS quantum dots (CuInS{sub 2}/ZnS/TGA QDs) was established for cobalt ions detection. The fluorescence quenching of CuInS{sub 2}/ZnS/TGA QDs was due to the increasing surface deficiency and the inner-filter effect, which were attributed to the reaction between Co{sup 2+} and sulfur bonds on the surface of QDs. The quenching curve could be fitted by a typical Stern–Volmer-type equation, with a linear relationship between the quenching efficiency and the concentration of cobalt ions in the range of 0.3012–90.36 μmol L{sup −1}. And the detection limit (S/N=3) for Co{sup 2+} was 0.16 μmol L{sup −1}. Therefore, the established probe provided a simple, rapid, cheap and sensitive method for Co{sup 2+} detection. In a word, this method can be used to detect Co{sup 2+} in the environment. -- Highlights: • The CuInS2/ZnS QDs were used for the first time as a fluorescent probe for Co{sup 2+} detection. • The dramatic color change could be observed when Co{sup 2+} was added into the QDs solution. • The quenching of QDs was due to the increasing surface deficiency and the inner-filter effect. • This rapid, cheap and sensitive method was applied to the detection of Co{sup 2+} in simulated water.

  17. Oxidation of SO2 by stabilized Criegee intermediate (sCI radicals as a crucial source for atmospheric sulfuric acid concentrations

    Directory of Open Access Journals (Sweden)

    M. Boy

    2013-04-01

    Full Text Available The effect of increased reaction rates of stabilized Criegee intermediates (sCIs with SO2 to produce sulfuric acid is investigated using data from two different locations, SMEAR II, Hyytiälä, Finland, and Hohenpeissenberg, Germany. Results from MALTE, a zero-dimensional model, show that using previous values for the rate coefficients of sCI + SO2, the model underestimates gas phase H2SO4 by up to a factor of two when compared to measurements. Using the rate coefficients recently calculated by Mauldin et al. (2012 increases sulfuric acid by 30–40%. Increasing the rate coefficient for formaldehyde oxide (CH2OO with SO2 according to the values recommended by Welz et al. (2012 increases the H2SO4 yield by 3–6%. Taken together, these increases lead to the conclusion that, depending on their concentrations, the reaction of stabilized Criegee intermediates with SO2 could contribute as much as 33–46% to atmospheric sulfuric acid gas phase concentrations at ground level. Using the SMEAR II data, results from SOSA, a one-dimensional model, show that the contribution from sCI reactions to sulfuric acid production is most important in the canopy, where the concentrations of organic compounds are the highest, but can have significant effects on sulfuric acid concentrations up to 100 m. The recent findings that the reaction of sCI + SO2 is much faster than previously thought together with these results show that the inclusion of this new oxidation mechanism could be crucial in regional as well as global models.

  18. Metabolic engineering of cyanobacteria for photosynthetic 3-hydroxypropionic acid production from CO2 using Synechococcus elongatus PCC 7942.

    Science.gov (United States)

    Lan, Ethan I; Chuang, Derrick S; Shen, Claire R; Lee, Annabel M; Ro, Soo Y; Liao, James C

    2015-09-01

    Photosynthetic conversion of CO2 to chemicals using cyanobacteria is an attractive approach for direct recycling of CO2 to useful products. 3-Hydroxypropionic acid (3 HP) is a valuable chemical for the synthesis of polymers and serves as a precursor to many other chemicals such as acrylic acid. 3 HP is naturally produced through glycerol metabolism. However, cyanobacteria do not possess pathways for synthesizing glycerol and converting glycerol to 3 HP. Furthermore, the latter pathway requires coenzyme B12, or an oxygen sensitive, coenzyme B12-independent enzyme. These characteristics present major challenges for production of 3 HP using cyanobacteria. To overcome such difficulties, we constructed two alternative pathways in Synechococcus elongatus PCC 7942: a malonyl-CoA dependent pathway and a β-alanine dependent pathway. Expression of the malonyl-CoA dependent pathway genes (malonyl-CoA reductase and malonate semialdehyde reductase) enabled S. elongatus to synthesize 3 HP to a final titer of 665 mg/L. β-Alanine dependent pathway expressing S. elongatus produced 3H P to final titer of 186 mg/L. These results demonstrated the feasibility of converting CO2 into 3 HP using cyanobacteria. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  19. The system Sb2Te3-InS

    International Nuclear Information System (INIS)

    Safarov, M.G.; Gamidov, R.S.; Poladov, P.M.

    1991-01-01

    The system Sb 2 Te 3 -InS was investigated by the methods of physicochemical analysis. Its state diagram was constructed. It represents the stable diagonal of the mutual ternary system InTe-Sb 2 Te 3 -Sb 2 S 3 -InS. It was established that limited regions of α- and β-solid solutions on the basis of Sb 2 Te 3 and InS, achieving 15.5 and 8 mol.% respectively, formed in the system. Lattice periods of α- and β-solid solutions, their lattice volumes, number of atoms in them and densities were calculated

  20. Sb2S3:C/CdS p-n junction by laser irradiation

    International Nuclear Information System (INIS)

    Arato, A.; Cardenas, E.; Shaji, S.; O'Brien, J.J.; Liu, J.; Castillo, G. Alan; Das Roy, T.K.; Krishnan, B.

    2009-01-01

    In this paper, we report laser irradiated carbon doping of Sb 2 S 3 thin films and formation of a p-n junction photovoltaic structure using these films. A very thin carbon layer was evaporated on to chemical bath deposited Sb 2 S 3 thin films of approximately 0.5 μm in thickness. Sb 2 S 3 thin films were prepared from a solution containing SbCl 3 and Na 2 S 2 O 3 at 27 deg. C for 5 h and the films obtained were highly resistive. These C/Sb 2 S 3 thin films were irradiated by an expanded laser beam of diameter approximately 0.5 cm (5 W power, 532 nm Verdi laser), for 2 min at ambient atmosphere. Morphology and composition of these films were analyzed. These films showed p-type conductivity due to carbon diffusion (Sb 2 S 3 :C) by the thermal energy generated by the absorption of laser radiation. In addition, these thin films were incorporated in a photovoltaic structure Ag/Sb 2 S 3 :C/CdS/ITO/Glass. For this, CdS thin film of 50 nm in thickness was deposited on a commercially available ITO coated glass substrate from a chemical bath containing CdCl 2 , sodium citrate, NH 4 OH and thiourea at 70 deg. C . On the CdS film, Sb 2 S 3 /C layers were deposited. This multilayer structure was subjected to the laser irradiation, C/Sb 2 S 3 side facing the beam. The p-n junction formed by p-Sb 2 S 3 :C and n-type CdS showed V oc = 500 mV and J sc = 0.5 mA/cm 2 under illumination by a tungsten halogen lamp. This work opens up a new method to produce solar cell structures by laser assisted material processing

  1. Rational synthesis of high nuclearity Mo/Fe/S clusters: the reductive coupling approach in the convenient synthesis of (Cl(4)-cat)(2)Mo(2)Fe(6)S(8)(PR(3))(6) [R = Et, (n)Pr, (n)Bu] and the new [(Cl(4)-cat)(2)Mo(2)Fe(2)S(3)O(PEt(3))(3)Cl]-1/2(Fe(PEt(3))(2)(MeCN)(4)) and (Cl(4)-cat)(2)Mo(2)Fe(3)S(5)(PEt(3))(5) clusters.

    Science.gov (United States)

    Han, J; Koutmos, M; Ahmad, S A; Coucouvanis, D

    2001-11-05

    A general method for the synthesis of high nuclearity Mo/Fe/S clusters is presented and involves the reductive coupling of the (Et(4)N)(2)[(Cl(4)-cat)MoOFeS(2)Cl(2)] (I) and (Et(4)N)(2)[Fe(2)S(2)Cl(4)] (II) clusters. The reaction of I and II with Fe(PR(3))(2)Cl(2) or sodium salts of noncoordinating anions such as NaPF(6) or NaBPh(4) in the presence of PR(3) (R = Et, (n)Pr, or (n)Bu) affords (Cl(4)-cat)(2)Mo(2)Fe(6)S(8)(PR(3))(6) [R = Et (IIIa), (n)Pr (IIIb), (n)Bu (IIIc)], Fe(6)S(6)(PEt(3))(4)Cl(2) (IV) and (PF(6))[Fe(6)S(8)(P(n)Pr(3))(6)] (V) as byproducts. The isolation of (Et(4)N)[Fe(PEt(3))Cl(3)] (VI), NaCl, and SPEt(3) supports a reductive coupling mechanism. Cluster IV and V also have been synthesized by the reductive self-coupling of compound II. The reductive coupling reaction between I and II by PEt(3) and NaPF(6) in a 1:1 ratio produces the (Et(4)N)(2)[(Cl(4)-cat)Mo(L)Fe(3)S(4)Cl(3)] clusters [L = MeCN (VIIa), THF (VIIb)]. The hitherto unknown [(Cl(4)-cat)(2)Mo(2)Fe(2)S(3)O(PEt(3))(3)Cl](+) cluster (VIII) has been isolated as the 2:1 salt of the (Fe(PEt(3))(2)(MeCN)(4))(2+) cation after the reductive self-coupling reaction of I in the presence of Fe(PEt(3))(2)Cl(2). Cluster VIII crystallizes in the monoclinic space group P2(1)/c with a = 11.098(3) A, b = 22.827(6) A, c = 25.855(6) A, beta = 91.680(4) degrees, and Z = 4. The formal oxidation states of metal atoms in VIII have been assigned as Mo(III), Mo(IV), Fe(II), and Fe(III) on the basis of zero-field Mössbauer spectra. The Fe(PEt(3))(2)(MeCN)(4) cation of VIII is also synthesized independently, isolated as the BPh(4)(-) salt (IX), and has been structurally characterized. The reductive coupling of compound I also affords in low yield the new (Cl(4)-cat)(2)Mo(2)Fe(3)S(5)(PEt(3))(5) cluster (X) as a byproduct. Cluster X crystallizes in the monoclinic space group P2(1)/n with a = 14.811(3) A, b = 22.188(4) A, c = 21.864(4) A, beta = 100.124(3) degrees, and Z = 4 and the structure shows very short Mo

  2. Highly efficient hydrogen evolution based on Ni3S4@MoS2 hybrids supported on N-doped reduced graphene oxide

    Science.gov (United States)

    Xu, Xiaobing; Zhong, Wei; Wu, Liqian; Sun, Yuan; Wang, Tingting; Wang, Yuanqi; Du, Youwei

    2018-01-01

    Hydrogen evolution reaction (HER) through water splitting at low overpotential is an appealing technology to produce renewable energy, wherein the design of stable electrocatalysts is very critical. To achieve optimal electrochemical performance, a highly efficient and stable noble-metal-free HER catalyst is synthesized by means of a facile hydrothermal co-synthesis. It consists of Ni3S4 nanosheets and MoS2 nanolayers supported on N-doped reduced graphene oxide (Ni3S4/MoS2@N-rGO). The optimized sample provides a large amount of active sites that benefit electron transfer in 3D conductive networks. Thanks to the strong synergistic effect in the catalyst network, we achieved a low overpotential of 94 mV, a small Tafel slope of 56 mV/dec and remarkable durability in an acidic medium.

  3. Determination of indole-3-acetic acid and indole-3-butyric acid in mung bean sprouts using high performance liquid chromatography with immobilized Ru(bpy)3(2+)-KMnO4 chemiluminescence detection.

    Science.gov (United States)

    Xi, Zhijun; Zhang, Zhujun; Sun, Yonghua; Shi, Zuolong; Tian, Wei

    2009-07-15

    A novel method for determination of indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) in an extract from mung bean sprouts using high performance liquid chromatography (HPLC) with chemiluminescence (CL) detection is described. The method is based on the CL reaction of auxin (indole-3-acetic acid and indole-3-butyric acid) with acidic potassium permanganate (KMnO(4)) and tris(2,2'-bipyridyl)ruthenium(II), which was immobilized on the cationic ion-exchange resin. The chromatographic separation was performed on a Nucleosil RP-C18 column (i.d.: 250 mm x 4.6 mm, particle size: 5 microm, pore size: 100) with an isocratic mobile phase consisting of methanol-water-acetic acid (45:55:1, v/v/v). At a flow rate of 1.0 mL min(-1), the total run time was 20 min. Under the optimal conditions, the linear ranges were 5.0x10(-8) to 5.0x10(-6)g mL(-1) and 5.0x10(-7) to 1.0x10(-5)g mL(-1) for IAA and IBA, respectively. The detection limits were 2.0x10(-8)g mL(-1) and 2.0x10(-7)g mL(-1) for IAA and IBA, respectively. The relative standard deviation (RSD) of intra-day were 3.1% and 2.3% (n=11) for 2x10(-6)g mL(-1) IAA and 2x10(-6)g mL(-1) IBA; The relative standard deviations of inter-day precision were 6.9% and 4.9% for 2x10(-6)g mL(-1) IAA and 2x10(-6)g mL(-1) IBA. The proposed method had been successfully applied to the determination of auxin in mung bean sprouts.

  4. Synthesis of (1R,2S)-1-amino-2-vinylcyclopropanecarboxylic acid vinyl-ACCA) derivatives: key intermediates for the preparation of inhibitors of the hepatitis C virus NS3 protease.

    Science.gov (United States)

    Beaulieu, Pierre L; Gillard, James; Bailey, Murray D; Boucher, Colette; Duceppe, Jean-Simon; Simoneau, Bruno; Wang, Xiao-Jun; Zhang, Li; Grozinger, Karl; Houpis, Ioannis; Farina, Vittorio; Heimroth, Heidi; Krueger, Thomas; Schnaubelt, Jürgen

    2005-07-22

    (1R,2S)-1-Amino-2-vinylcyclopropanecarboxylic acid (vinyl-ACCA) is a key building block in the synthesis of potent inhibitors of the hepatitis C virus NS3 protease such as BILN 2061, which was recently shown to dramatically reduce viral load after administration to patients infected with HCV genotype 1. We have developed a scalable process that delivers derivatives of this unusual amino acid in >99% ee. The strategy was based on the dialkylation of a glycine Schiff base using trans-1,4-dibromo-2-butene as an electrophile to produce racemic vinyl-ACCA, which was subsequently resolved using a readily available, inexpensive esterase enzyme (Alcalase 2.4L). Factors that affect diastereoselection in the initial dialkylation steps were examined and the conditions optimized to deliver the desired diastereomer selectively. Product inhibition, which was encountered during the enzymatic resolution step, initially resulted in prolonged cycle times. Enrichment of racemic vinyl-ACCA through a chemical resolution via diastereomeric salt formation or the use of forcing conditions in the enzymatic reaction both led to improvements in throughput and the development of a viable process. The chemistry described herein was scaled up to produce multikilogram quantities of this building block.

  5. Synthesis of a new intercalating nucleic acid 6H-INDOLO[2,3-b] quinoxaline oligonucleotides to improve thermal stability of Hoogsteen-type triplexes

    DEFF Research Database (Denmark)

    Osman, Amany M A; Pedersen, Erik Bjerregaard; Bergman, Jan

    2013-01-01

    A new intercalating nucleic acid monomer X was obtained in high yield starting from alkylation of 4-iodophenol with (S)-(+)-2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethanol under Mitsunobu conditions followed by hydrolysis with 80% aqueous acetic acid to give a diol which was coupled under Sonogashira c...

  6. The omega-6/omega-3 fatty acid ratio: health implications

    Directory of Open Access Journals (Sweden)

    Simopoulos Artemis P.

    2010-09-01

    Full Text Available Today, Western diets are characterized by a higher omega-6 and a lower omega-3 fatty acid intake, whereas during the Paleolithic period when human’s genetic profile was established, there was a balance between omega-6 and omega-3 fatty acids. Their balance is an important determinant for brain development and in decreasing the risk for coronary heart disease (CHD, hypertension, cancer, diabetes, arthritis, and other autoimmune and possibly neurodegenerative diseases. Both omega-6 and omega-3 fatty acids influence gene expression. Because of single nucleotide polymorphisms (SNPs in their metabolic pathways, blood levels of omega-6 and omega-3 fatty acids are determined by both endogenous metabolism and dietary intake making the need of balanced dietary intake essential for health and disease prevention. Whether an omega-6/omega-3 ratio of 3:1 to 4:1 could prevent the pathogenesis of many diseases induced by today’s Western diets (AFSSA, 2010, a target of 1:1 to 2:1 appears to be consistent with studies on evolutionary aspects of diet, neurodevelopment, and genetics. A target of omega-6/omega-3 fatty acid ratio of 1:1 to 2:1 appears to be consistent with studies on evolutionary aspects of diet, neurodevelopment and genetics. A balanced ratio of omega-6/omega-3 fatty acids is important for health and in the prevention of CHD and possibly other chronic diseases.

  7. {μ-2-[4-(1,3-Benzothiazol-2-ylphenyl]-2-azapropane-1,3-dithiolato-κ4S,S′:S,S′}bis[tricarbonyliron(I

    Directory of Open Access Journals (Sweden)

    Da-yong Jiang

    2012-03-01

    Full Text Available The title compound, [Fe2(C15H12N2S3(CO6], was prepared as an azadithiolatodiiron model for the active site of [FeFe]-hydrogenase. The Fe2S2 core adopts a butterfly shape, with each metal having a pseudo square-pyramidal geometry. The N-substituted azadithiolate is μ2-κ4S,S′:S,S′-coordinated to the Fe(CO3 moieties to form two fused six-membered rings with different conformations. The sum of the C—N—C angles around the N atom [356.85 (15°] indicates a flattening of the trigonal–pyramidal geometry about the N atom and an increase in the degree of sp2-hybridization.

  8. Fluorescence properties of 3-amino phenylboronic acid and its interaction with glucose and ZnS:Cu quantum dots.

    Science.gov (United States)

    Kur-Kowalska, Karolina; Przybyt, Małgorzata; Ziółczyk, Paulina; Sowiński, Przemysław; Miller, Ewa

    2014-08-14

    Preliminary results of a study of the interaction between 3-amino phenylboronic acid and glucose or ZnS:Cu quantum dots are presented in this paper. ZnS:Cu quantum dots with mercaptopropionic acid as a capping agent were obtained and characterized. Quenching of 3-amino phenylboronic acid fluorescence was studied by steady-state and timeresolved measurements. For fluorescence quenching with glucose the results of steady-state measurements fulfill Stern-Volmer equation. The quenching constants are increasing with growing pH. The decay of fluorescence is monoexponential with lifetime about 8.4 ns, which does not depend on pH and glucose concentration indicating static quenching. The quenching constant can be interpreted as apparent equilibrium constant of estrification of boronic group with diol. Quantum dots are also quenching 3-amino phenylboronic acid fluorescence. Fluorescence lifetime, in this case, is slightly decreasing with increasing concentration of quantum dots. The quenching constants are increasing slightly with pH's growth. Quenching mechanism of 3-amino phenylboronic acid fluorescence by quantum dots needs further experiments to be fully explained. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. 2D double-layer-tube-shaped structure Bi2S3/ZnS heterojunction with enhanced photocatalytic activities

    International Nuclear Information System (INIS)

    Gao, Xiaoming; Wang, Zihang; Fu, Feng; Li, Xiang; Li, Wenhong

    2015-01-01

    Bi 2 S 3 /ZnS heterojunction with 2D double-layer-tube-shaped structures was prepared by the facile synthesis method. The corresponding relationship was obtained among loaded content to phase, morphology, and optical absorption property of Bi 2 S 3 /ZnS composite. The results shown that Bi 2 S 3 loaded could evidently change the crystallinity of ZnS, enhance the optical absorption ability for visible light of ZnS, and improve the morphologies and microstructure of ZnS. The photocatalytic activities of the Bi 2 S 3 /ZnS sample were evaluated for the photodegradation of phenol and desulfurization of thiophene under visible light irradiation. The results showed that Bi 2 S 3 loaded greatly improved the photocatalytic activity of ZnS, and the content of loaded Bi 2 S 3 had an impact on the catalytic activity of ZnS. Moreover, the mechanism of enhanced photocatalytic activity was also investigated by analysis of relative band positions of Bi 2 S 3 and ZnS, and photo-generated hole was main active radicals during photocatalytic oxidation process

  10. 2D double-layer-tube-shaped structure Bi2S3/ZnS heterojunction with enhanced photocatalytic activities

    Science.gov (United States)

    Gao, Xiaoming; Wang, Zihang; Fu, Feng; Li, Xiang; Li, Wenhong

    2015-10-01

    Bi2S3/ZnS heterojunction with 2D double-layer-tube-shaped structures was prepared by the facile synthesis method. The corresponding relationship was obtained among loaded content to phase, morphology, and optical absorption property of Bi2S3/ZnS composite. The results shown that Bi2S3 loaded could evidently change the crystallinity of ZnS, enhance the optical absorption ability for visible light of ZnS, and improve the morphologies and microstructure of ZnS. The photocatalytic activities of the Bi2S3/ZnS sample were evaluated for the photodegradation of phenol and desulfurization of thiophene under visible light irradiation. The results showed that Bi2S3 loaded greatly improved the photocatalytic activity of ZnS, and the content of loaded Bi2S3 had an impact on the catalytic activity of ZnS. Moreover, the mechanism of enhanced photocatalytic activity was also investigated by analysis of relative band positions of Bi2S3 and ZnS, and photo-generated hole was main active radicals during photocatalytic oxidation process.

  11. Synthesis and pharmacology of 3-hydroxy-delta2-isoxazoline-cyclopentane analogues of glutamic acid

    DEFF Research Database (Denmark)

    Conti, P; De Amici, M; Bräuner-Osborne, Hans

    2002-01-01

    The synthesis and pharmacology of two potential glutamic acid receptor ligands are described. Preparation of the bicyclic 3-hydroxy-delta2-isoxazoline-cyclopentane derivatives (+/-)-7 and (+/-)-8 was accomplished via 1,3-dipolar cycloaddition of bromonitrile oxide to suitably protected 1-amino......-cyclopent-3-enecarboxylic acids. Their structure was established using a combination of 1H NMR spectroscopy and molecular mechanics calculations carried out on the intermediate cycloadducts (+/-)-11 and (+/-)-12. Amino acid derivatives (+/-)-7 and (+/-)-8 were assayed at ionotropic and metabotropic glutamic...... acid receptor subtypes and their activity compared with that of trans-ACPD and cis-ACPD. The results show that the replacement of the omega-carboxylic group of the model compounds with the 3-hydroxy-delta2-isoxazoline moiety abolishes or reduces drastically the activity at the metabotropic glutamate...

  12. Absorption and metabolism of the food contaminant 3-chloro-1,2-propanediol (3-MCPD) and its fatty acid esters by human intestinal Caco-2 cells.

    Science.gov (United States)

    Buhrke, Thorsten; Weisshaar, Rüdiger; Lampen, Alfonso

    2011-10-01

    3-Chloro-1,2-propanediol (3-MCPD) fatty acid esters are formed upon thermal processing of fat-containing foods in the presence of chloride ions. Upon hydrolytic cleavage, these substances could release free 3-MCPD. This compound is toxicologically well characterised and displayed cancerogenic potential in rodent models. Recently, serious contaminations of different food products with 3-MCPD fatty acid esters have been reported. In regard to a risk assessment, the key question is to which degree these 3-MCPD fatty acid esters are hydrolysed in the human gut. Therefore, the aim of the present project was to examine the hydrolysis of 3-MCPD fatty acid esters and the resulting release of free 3-MCPD by using differentiated Caco-2 cells, a cellular in vitro model for the human intestinal barrier. Here, we show that 3-MCPD fatty acid esters at a concentration of 100 μM were neither absorbed by the cells nor the esters were transported via a Caco-2 monolayer. 3-MCPD-1-monoesters were hydrolysed in the presence of Caco-2 cells. In contrast, a 3-MCPD-1,2-diester used in this study was obviously absorbed and metabolised by the cells. Free 3-MCPD was not absorbed by the cells, but the substance migrated through a Caco-2 monolayer by paracellular diffusion. From these in vitro studies, we conclude that 3-MCPD-1-monoesters are likely to be hydrolysed in the human intestine, thereby increasing the burden with free 3-MCPD. In contrast, intestinal cells seem to have the capacity to metabolise 3-MCPD diesters, thereby detoxifying the 3-MCPD moiety.

  13. Mean life of the 2p4(1S)3s 2S state in fluorine

    International Nuclear Information System (INIS)

    Cheng, K.T.; Chen, M.H.

    1985-01-01

    In this work, we calculate the radiationless as well as the radiative decay rates for the 2p 4 ( 1 S)3s 2 S state. For comparison purposes, we also make similar calculations for the 2p 4 ( 1 D)4s 2 D state. Our calculation is based on the multi-configuration Dirac-Fock (MCDF) method. As spin-orbit interaction is built in, this method is capable of studying LS forbidden Auger transitions. Details of the Auger transition calculations have been given before. 9 refs

  14. H3PO4/Al2O3 catalysts: characterization and catalytic evaluation of oleic acid conversion to biofuels and biolubricant

    Directory of Open Access Journals (Sweden)

    Lucia Regina Raddi de Araujo

    2006-06-01

    Full Text Available Al2O3 and H3PO4/Al2O3 catalysts were investigated in the conversion of oleic acid to biofuels and biolubricant at 1 atm and at 623 K. The catalytic tests were performed in a fixed bed and continuous flow reactor, using an oleic acid-catalyst ratio of 4 and N2 as the carrier gas. The reaction products were analyzed by gas chromatography and acidity measurements. N2 adsorption-desorption, X ray diffraction, 31P nuclear magnetic resonance and FT-IR spectroscopy were also employed to evaluate the textural, structural and acidic properties of the catalysts. The results showed that phosphoric acid impregnation improved the alumina decarboxylation activities, generating hydrocarbons in the range of gasoline, diesel oil and lubricant oil. The best catalytic performance was achieved with the highest surface area alumina impregnated with H3PO4, which was the solid that allied high total acidity with a large quantity of mesopores.

  15. Effect of Enriched Feed by n-3 fatty acids and 2% of n-6 fatty acid on Danio rerio Reproduction

    Directory of Open Access Journals (Sweden)

    N.B.P Utomo

    2007-07-01

    Full Text Available This experiment was conducted to determine the optimum n-3 fatty acid level in the diet containing 2 % of n-6 fatty acid on the reproductive performance of zebra fish (Danio rerio. There experimental diets containing 0.0; 1.0; 1.5 % n-3 fatty acid with 2.0 % n-6 fatty acid was fed to the fish, three times daily, at satiation, for two months. In order to evaluate the gonadal development of the broodstock, two gonads og fish was used for histologis preparation in every 7 days. At the end of the second month, reproductive performance was evaluated through parameters of gonad somato indeks, fecundity, fertilization rate, hatching rate, yolk egg absorbtion rate, survival rate of 3 days old larvae. Sample of fish also was taken for proximate composition as the end of this experiment. Results shows that at the fifth weeks of this experiment, gonad of fish fed on 1.0 % of n-3 fatty acid and 2.0 % n-6 fatty acid already produce eggs with the some size, while others. Still produce small size of eggs. It was found also that the whole body of fish fed an diet with 1.0% n-3 fatty acid contain the highest protein level compare to two other diets. Based on the evaluation of reproduction performance parameters, it was concluded that the optimum dietary level of n-3 fatty acid with 2.0 % n-6 fatty acid for Danio rerio was 0.81 - 0.90 %. Keywords: essential fatty, acids, reproduction, zebra fish, Danio rerio   ABSTRAK Penelitian ini bertujuan untuk menentukan kadar asam lemak n-3 optimum dalam pakan yang mempunyai kadar asam lemak n-6 tetap. Tiga macam pakan dengan kadar asam lemak n-3 berbeda yaitu 0.0; 1.0; dan 2.0 % diberikan pada ikan dengan bobot rata-rata 0.12 g. Pakan diberikan secara at satiation, 4 kali sehari selama 60 hari. Setiap 7 hari sekali diambil sampel ikan untuk pembentukan preparat histologi gonad dengan tujuan untuk mengevaluasi perkembangan gonad. Pada akhir penelitian, induk dipijahkan dan dievaluasi performan reproduksi berdasarkan

  16. SYNTHESIS AND CHARACTERISTIC OF 2-HYDROXYPROPYLENE- 1,3-DIAMINETETRAACETOGERMANATES OF SOME s-METALS

    Directory of Open Access Journals (Sweden)

    E. E. Marzinko

    2014-12-01

    Full Text Available Differentmetal complexes of germanium (IV and s-metals (Mg, Ca, Sr, Ba with 2-hydroxypropylene-1,3-diamino-N,N,NI,NI-tetraacetic acid (Н5 Hpdta are obtained for the first time and characterized by methods of elementary and X-Ray powder diffraction analysis, thermogravimetry, IR-specroscopy. By results of research by set of physical and chemical methods it is established, that obtained 2-hydroxypropylene-1,3-diaminetetraacetogermanates are complexes of cationic-anionic type: M[Ge(Hpdta(ОН(Н2О]·nH2O, where M = Mg, n=9 (I; Ca, n=7 (II, Sr, n=7 (III; Ba, n=8 (IV. The scheme of structure of compounds I-IV is offered.

  17. Antioxidant activity of salts of 2-(5-R-4-amino-1,2,4-triazole-3-ylthioacetic acid

    Directory of Open Access Journals (Sweden)

    Ye. S. Pruglo

    2017-12-01

    Full Text Available Antioxidants are chemical structures that prevent the oxidation of other chemicals. They protect key cell components by neutralizing the harmful effect of free radicals which are natural products of cell metabolism. Oxidative stress leads to serious cell damage which results in various human diseases such as Alzheimer's disease, Parkinson's disease, atherosclerosis, cancer, arthritis, neurodegenerative disorders etc. The deficiency of antioxidants in food also leads to oxidative stress, which indicates a lack of antioxidant substances consumed by humans. Therefore, the search of substances that could not only prevent but also increase the resistance of the human body to active forms of oxygen or nitrogen and interfere with the processes of oxidative stress is an important task of medicine and pharmacy. The purpose of this work was to study the antioxidant activity (AOA of salts of 2-(5-R-4-R-4H-1,2,4-triazole-3-ylthioacetic acids with non-enzymatic initiation of free radical oxidation and to establish laws concerning chemical structure and biological effects of the studied substances. Materials and methods. Original derivatives of 1,2,4-triazole were used in the series of screening studies. The antioxidant activity of the compounds in vitro was determined according to the methodical recommendations of the State Pharmacological Center MoH Ukraine using the method of non-enzymatic initiation of lipid peroxide oxidation. Results. Dimethylammonium salt of 2-(4-amino-5-(2-bromophenyl-1,2,4-triazole-3-ylthioacetic acid (3c possessed with a high AOA which reduced the content of TBK-AP by 54,95% ( р˂0,001. Derivatives of 4-amino-1,2,4-triazole had the most distinct AOA containing С5 carbon atoms 2-bromophenyl substituent. Thus, methylammonium salt 3b reduced the TBK-AP content by 80,31 (p˂0,001 which exceeds the reference ascorbic acid by 45,05% and the prototype thiotriazoline by 36,64%. Considering the data of experimental studies it was found

  18. ASPECTS NUTRITIONNELS DES ACIDES GRAS POLYINSATURES n-3 Augmentation sélective de la sensibilité des tumeurs à la chimiothérapie par les acides gras polyinsaturés n-3

    Directory of Open Access Journals (Sweden)

    Bougnoux Philippe

    2000-01-01

    Full Text Available L’alimentation intervient à différents niveaux dans le déroulement de la maladie cancéreuse : au niveau du risque [1] et au niveau de l’évolution en modifiant le risque de survenue des métastases. L’alimentation influence-t-elle aussi la réponse aux traitements anticancéreux ? À l’appui de cette hypothèse viennent deux observations indirectes réalisées dans le cancer du sein : nos données [2, 3] ainsi que les observations épidémiologiques provenant d’autres travaux [4] ont apporté des arguments supportant l’hypothèse que les lipides alimentaires peuvent influencer la réponse des tumeurs mammaires aux traitements. On sait que la composition des lipides membranaires n’est pas génétiquement déterminée, mais qu’elle dépend des acides gras disponibles aux tissus périphériques. Le type d’acides gras disponibles est influencé par les apports alimentaires. Comme les tumeurs incorporent dans leurs lipides les acides gras disponibles de façon similaire aux autres tissus [5], il est plausible que les habitudes alimentaires (apports alimentaires en acides gras polyinsaturés, vitamines anti ou pro-oxydantes puissent influencer leur chimiosensibilité en apportant aux cellules tumorales des substrats de peroxydation.

  19. F-theory and AdS3/CFT2 (2, 0)

    Science.gov (United States)

    Couzens, Christopher; Martelli, Dario; Schäfer-Nameki, Sakura

    2018-06-01

    We continue to develop the program initiated in [1] of studying supersymmetric AdS3 backgrounds of F-theory and their holographic dual 2d superconformal field theories, which are dimensional reductions of theories with varying coupling. Imposing 2d N=(0,2) supersymmetry,wederivethegeneralconditionsonthegeometryforTypeIIB AdS3 solutions with varying axio-dilaton and five-form flux. Locally the compact part of spacetime takes the form of a circle fibration over an eight-fold Y_8^{τ } , which is elliptically fibered over a base \\tilde{M}_6 . We construct two classes of solutions given in terms of a product ansatz \\tilde{M}_6}=Σ × {M}_4 , where Σ is a complex curve and \\tilde{M}_4 is locally a Kähler surface. In the first class \\tilde{M}_4 is globally a Kähler surface and we take the elliptic fibration to vary non-trivially over either of these two factors, where in both cases the metrics on the total space of the elliptic fibrations are not Ricci-flat. In the second class the metric on the total space of the elliptic fibration over either curve or surface are Ricci-flat. This results in solutions of the type AdS3 × K3 × ℳ 5 τ , dual to 2d (0, 2) SCFTs, and AdS3 × S 3/Γ × CY 3, dual to 2d (0, 4) SCFTs, respectively. In all cases we compute the charges for the dual field theories with varying coupling and find agreement with the holographic results. We also show that solutions with enhanced 2d N=(2,2) supersymmetry must have constant axio-dilaton. Allowing the internal geometry to be non-compact leads to the most general class of Type IIB AdS5 solutions with varying axio-dilaton, i.e. F-theoretic solutions, that are dual to 4d N=1 SCFTs.

  20. Standard molar enthalpies of formation of 2-, 3- and 4-cyanobenzoic acids

    International Nuclear Information System (INIS)

    Ribeiro da Silva, Manuel A.V.; Amaral, Luisa M.P.F.; Boaventura, Cristina R.P.; Gomes, Jose R.B.

    2008-01-01

    The standard (p 0 = 0.1 MPa) molar enthalpies of formation of 2-, 3- and 4-cyanobenzoic acids were derived from their standard molar energies of combustion, in oxygen, at T = 298.15 K, measured by static bomb combustion calorimetry. The Calvet high temperature vacuum sublimation technique was used to measure the enthalpies of sublimation of 2- and 3-cyanobenzoic acids. The standard molar enthalpies of formation of the three compounds, in the gaseous phase, at T = 298.15 K, have been derived from the corresponding standard molar enthalpies of formation in the condensed phase and standard molar enthalpies for phase transition. The results obtained are -(150.7 ± 2.0) kJ . mol -1 , -(153.6 ± 1.7) kJ . mol -1 and -(157.1 ± 1.4) kJ . mol -1 for 2-cyano, 3-cyano and 4-cyanobenzoic acids, respectively. Standard molar enthalpies of formation were also estimated by employing two different methodologies: one based on the Cox scheme and the other one based on several different computational approaches. The calculated values show a good agreement with the experimental values obtained in this work

  1. 2-(5-Bromo-3-isopropylsulfanyl-1-benzofuran-2-ylacetic acid

    Directory of Open Access Journals (Sweden)

    Pil Ja Seo

    2012-01-01

    Full Text Available The title compound, C13H13BrO3S, was prepared by alkaline hydrolysis of ethyl 2-(5-bromo-3-isopropylsulfanyl-1-benzofuran-2-ylacetate. In the crystal, the carboxyl groups are involved in intermolecular O—H...O hydrogen bonds, which link the molecules into dimers. These dimers are further packed into stacks along the c axis by intermolecular C—H...π interactions, and by slipped π–π interactions between the furan rings of adjacent molecules [centroid–centroid distance = 3.472 (2 Å, interplanar distance = 3.398 (2 Å and slippage = 0.713 (2 Å].

  2. Formation of copper nanoparticles in mordenite s with variable SiO{sub 2}/Al{sub 2}O{sub 3} molar ratios under redox treatments

    Energy Technology Data Exchange (ETDEWEB)

    Petranovskii, V.; Avalos, M. [UNAM, Centro de Nanociencias y Nanotecnologia, Km 107 Carretera Tijuana-Ensenada, 22800 Ensenada, Baja California (Mexico); Stoyanov, E. [University of California, Department of Chemistry, Riverside, 92521 California (United States); Gurin, V. [Belarusian State University, Research Institute for Physical Chemical Problems, Minsk 220080 (Belarus); Katada, N. [Tottori University, Department of Chemistry and Biotechnology, Tottori 680-8552 (Japan); Hernandez, M. A. [Benemerita Universidad Autonoma de Puebla, Departamento de Investigacion en Zeolitas, Ciudad Universitaria, Puebla (Mexico); Pestryakov, A. [Tomsk Polytechnic University, Tomsk 634050 (Russian Federation); Chavez R, F.; Zamorano U, R. [IPN, Escuela Superior de Fisica y Matematicas, Departamento de Fisica, Zacatenco, 07738 Mexico D. F. (Mexico); Portillo, R., E-mail: vitalii@cnyn.unam.mx [Benemerita Universidad Autonoma de Puebla, Facultad de Ciencias Quimicas, Ciudad Universitaria, Puebla (Mexico)

    2013-05-01

    A series of protonated copper-containing mordenite s with different SiO{sub 2}/Al{sub 2}O{sub 3} molar ratios (MR) in the range of 10{<=}MR{<=}206 was prepared by ion exchange in copper nitrate aqueous solution. The electron paramagnetic resonance of hydrated copper Mordenite s series testifies of several Cu{sup 2+} ion sites. Hydrogen reduction of copper ions incorporated into the mordenite s was shown to lead to different reduced copper species including small metallic particles inter alia. The structural properties and acidity of mordenite s were characterized. The optical appearance of the copper particles showed strong but nonmonotonic dependence on the MR value, in line with the variation in acidity of this series of mordenite s. Correlations between mordenite properties and the formation of different reduced copper species are discussed. (Author)

  3. Resolution of TBP-H/sub 2/MBP-HDBP-H/sub 3/PO/sub 4/. Application to UO/sub 2/(NO/sub 3/)/sub 2/-TBP, Th(NO/sub 3/)/sub 4/-TBP, and ZrO(NO/sub 3/)/sub 2/-TBP systems. [Separation of dibutyl phosphoric acid, monobutylphosphoric acid and orthophosphoric acid from tri-butylphosphate

    Energy Technology Data Exchange (ETDEWEB)

    Pires, M A.F.; Abrao, A

    1981-04-01

    Several schemes for the separation of dibutylphosphoric acid (HDBP), monobutylphosphoric acid (H/sub 2/MBP) and orthophosphoric acid (H/sub 3/PO/sub 4/) as hydrolytic and radiolytic degradation products from tri-n-butylphosphate (TBP) were studied. For the resolution of a HDBP, H/sub 2/MPB and H/sub 3/PO/sub 4/ mixture in TBP-diluent, or in TBP-diluent-heavy metal nitrate (U-VI, Th-IV or Zr-IV), techniques such as ion exchange chromatography, ion chromatography and separation onto a chromatographic alumina column were investigated. For the identification, determination and analytical resolution following up for the several systems studied, techniques such as refraction index measurement, electrical conductivity measurement, molecular spectrophotometry and gas chromatography were applied. Special emphasis was given to the separation using alumina column where the HDBP acid was retained and eluted selectively for its separation from TBP-varsol-uranyl nitrate mixtures. This analytical procedure was applied to the samples coming from the Uranium Purification Pilot Plant in operation at the Centro de Engenharia Quimica (IPEN).

  4. 1,2,3-triazolyl amino acids as AMPA receptor ligands

    DEFF Research Database (Denmark)

    Stanley, Nathan J.; Pedersen, Daniel Sejer; Nielsen, Birgitte

    2010-01-01

    The central nervous system glutamate receptors are an important target for drug discovery. Herein we report initial investigations into the synthesis and glutamate receptor activity of 1,2,3-triazolyl amino acids. Two compounds were found to be selective AMPA receptor ligands, which warrant further...

  5. Thermochemical study of 2,4-, 2,6- and 3,4-dihydroxybenzoic acids in the liquid phase using a TG apparatus

    International Nuclear Information System (INIS)

    Vecchio, Stefano; Brunetti, Bruno

    2011-01-01

    Research highlights: → Vapor pressures of solid and liquid 2,4- 2,6- and 3,4-dihydroxybenzoic acids, that don't decompose appreciably in the temperature range considered, were determined by torsion-effusion technique and thermogravimetry, respectively. → Agreement between the experimental sublimation vapor pressures and literature data recently published is good for all the three isomers. → From the temperature dependence of vapor pressure the molar enthalpies of sublimation and vaporization were determined at the middle of the respective experimental temperature intervals. → For validation of TG pressure data, the TG vapor pressures of solid ferrocene and 1,2-dihydroxybenzoic acid were successfully compared with the corresponding literature values. → The following increasing-order of volatility can be established: 2,6-dihydroxybenzoic acid l g H m o ( ) were determined, respectively, at the middle of the respective temperature intervals. The melting temperatures and the molar enthalpies of fusion of these compounds were measured by d.s.c. The vapor pressures of these compounds in the solid state, measured by torsion-effusion technique, were compared with recently published data, while the corresponding molar sublimation enthalpies were determined. In order to validate the vapor pressure results determined by TG, the experimental vapor pressure data regarding solid ferrocene and 1,2-dihydroxybenzoic acid were successfully compared with literature values in the range 20-200 Pa. In addition, the experimental molar enthalpies of fusion were compared with those calculated by subtracting the molar vaporization enthalpies to the sublimation ones, both adjusted to their respective melting temperatures. Finally, the standard (p o = 0.1 MPa) molar enthalpies, entropies and Gibbs energies of sublimation, corrected at the reference temperature of 298.15 K, have been calculated using the estimated heat capacity differences between gas and liquid for vaporization

  6. Dicyclohexylammonium (S-2-azido-3-phenylpropanoate

    Directory of Open Access Journals (Sweden)

    Sebastian J. Petrik

    2012-07-01

    Full Text Available The asymmetric unit of the title compound, C12H24N+·C9H8N3O2−, consists of two dicyclohexylammonium cations linked to two (S-2-azido-3-phenylpropanoate anions by four short N—H...O hydrogen bonds with N...O distances in the range 2.712 (32.765 (3 Å. The dicyclohexylammonium cations and the aryl and carboxylate groups of the anion are related by a pseudo-inversion centre, with overall crystallographic inversion symmetry for the structure broken by the chirality of the α-C atoms of the anions.

  7. High-pressure polymorphism of As2S3 and new AsS2 modification with layered structure

    Science.gov (United States)

    Bolotina, N. B.; Brazhkin, V. V.; Dyuzheva, T. I.; Katayama, Y.; Kulikova, L. F.; Lityagina, L. V.; Nikolaev, N. A.

    2014-01-01

    At normal pressure, the As2S3 compound is the most stable equilibrium modification with unique layered structure. The possibility of high-pressure polymorphism of this substance remains questionable. Our research showed that the As2S3 substance was metastable under pressures P > 6 GPa decomposing into two high-pressure phases: As2S3 → AsS2 + AsS. New AsS2 phase can be conserved in the single crystalline form in metastable state at room pressure up to its melting temperature (470 K). This modification has the layered structure with P1211 monoclinic symmetry group; the unit-cell values are a = 7.916(2) Å, b = 9.937(2) Å, c = 7.118(1) Å, β = 106.41° ( Z = 8, density 3.44 g/cm3). Along with the recently studied AsS high-pressure modification, the new AsS2 phase suggests that high pressure polymorphism is a very powerful tool to create new layered-structure phases with "wrong" stoichiometry.

  8. 5-[3-(2,5-Dimethoxyphenylprop-2-enylidene]-1,3-diethyl-2-thioxohexahydropyrimidine-4,6-dione

    Directory of Open Access Journals (Sweden)

    Abdullah Mohamed Asiri

    2009-08-01

    Full Text Available 1,3-Diethyl-2-thiobarbituric acid reacts with 2,5-dimethoxybenzaldehyde to form the title Knoevenagel product, C19H22N2O4S. In the compound, the two six-membered rings at either end of the three-membered –CHCHCH– chain are nearly coplanar with this fragment (r.m.s. deviation of the two six-membered rings and the three chain atoms = 0.08 Å.

  9. The Usability of Boric Acid as an Alternative Foaming Agent on the Fabrication of Al/Al2O3 Composite Foams

    Science.gov (United States)

    Yaman, Bilge; Onuklu, Eren; Korpe, Nese O.

    2017-09-01

    Pure Al and alumina (2, 5, 10 wt.% Al2O3)-added Al composite foams were fabricated through powder metallurgy technique, where boric acid (H3BO3) is employed as a new alternative foaming agent. It is aimed to determine the effects of boric acid on the foaming behavior and cellular structure and also purposed to develop the mechanical properties of Al foams by addition of Al2O3. Al and Al composite foams with porosity fraction in the range of 46-53% were achieved by sintering at 620 °C for 2 h. Cell morphology was characterized using a combination of stereomicroscope equipped with image analyzer and scanning electron microscopy. Microhardness values were measured via using Vickers indentation technique. Quasi-static compression tests were performed at strain rate of 10-3 s-1. Compressive strength and energy absorption of the composite foams enhanced not only by the increasing weight fraction of alumina, but also by the usage of boric acid which leads to formation of boron oxide (B2O3) acting as a binder in obtaining dense cell walls. The results revealed that the boric acid has outstanding potential as foaming agent in the fabrication of Al and Al composite foams by providing improved mechanical properties.

  10. Low irradiances affect abscisic acid, indole-3-acidic acid, and cytokinin levels of wheat (Triticum aestivum L.) tissues

    Science.gov (United States)

    Nan, R.; Carman, J. G.; Salisbury, F. B.

    1999-01-01

    Wheat (Triticum aestivum L.) plants were grown under four irradiance levels: 1,400, 400, 200, and 100 micromol m-2 s-1. Leaves and roots were sampled before, during, and after the boot stage, and levels of abscisic acid (ABA), indole-3-acetic acid (IAA), zeatin, zeatin riboside, dihydrozeatin, dihydrozeatin riboside, isopentenyl adenine, and isopentenyl adenosine were quantified using noncompetitive indirect ELISA systems. Levels of IAA in leaves and roots of plants exposed to 100 micromol m-2 s-1 of irradiance were 0.7 and 2.9 micromol kg-1 dry mass (DM), respectively. These levels were 0.2 and 1.0 micromol kg-1 DM, respectively, when plants were exposed to 1,400 micromol m-2 s-1. Levels of ABA in leaves and roots of plants exposed to 100 micromol m-2 s-1 were 0.65 and 0.55 micromol kg-1 DM, respectively. They were 0.24 micromol kg-1 DM (both leaves and roots) when plants were exposed to 1,400 micromol m-2 s-1. Levels of isopentenyl adenosine in leaves (24.3 nmol kg-1 DM) and roots (29.9 nmol kg-1 DM) were not affected by differences in the irradiance regime. Similar values were obtained in a second experiment. Other cytokinins could not be detected (<10 nmol kg 1 DM) in either experiment with the sample sizes used (150-600 mg DM for roots and shoots, respectively).

  11. Saccharomyces boulardii expresses neuraminidase activity selective for α2,3-linked sialic acid that decreases Helicobacter pylori adhesion to host cells.

    Science.gov (United States)

    Sakarya, Serhan; Gunay, Necati

    2014-10-01

    Helicobacter pylori is a major causative agent of gastritis and peptic ulcer disease and is an established risk factor for gastric malignancy. Antibiotic combination therapy can eradicate H. pylori. As these same regimens can evoke adverse effects and resistance, new alternative therapies or adjunctive treatments are needed. A probiotic approach may provide a novel strategy for H. pylori treatment. In the current study, two probiotic bacteria, Lactobacillus acidophilus and Lactobacillus reuteri, and a probiotic yeast, Saccharomyces boulardii, were evaluated for their ability to influence H. pylori viability, adherence to gastric and duodenal cells, as well as the effect of S. boulardii on cell surface expression of sialic acid. Our results indicate that S. boulardii contains neuraminidase activity selective for α(2-3)-linked sialic acid. This neuraminidase activity removes surface α(2-3)-linked sialic acid, the ligand for the sialic acid-binding H. pylori adhesin, which in turn, inhibits H. pylori adherence to duodenal epithelial cells. © 2014 APMIS. Published by John Wiley & Sons Ltd.

  12. Identification of new derivatives of 2-S-glutathionylcaftaric acid in aged white wines by HPLC-DAD-ESI-MS(n).

    Science.gov (United States)

    Cejudo-Bastante, María Jesús; Pérez-Coello, María Soledad; Hermosín-Gutiérrez, Isidro

    2010-11-10

    Glutathione, a natural occurring antioxidant, is a thiol-containing peptide present in grape must and wine. It is able to regenerate the o-diphenol group of enzymatically oxidized trans-caftaric acid, giving rise to 2-S-glutathionyl-trans-caftaric acid (also known as grape reaction product, GRP) and thus inhibiting the browning of wine. The amount of GRP present in a wine provides information on the oxidation history of the wine over its elaboration and aging. GRP has been proved to suffer hydrolysis in model solutions and wines. To know the actual content of glutathione involved in white wine browning inhibition as GRP, the GRP-derived products have been studied in 1-year-aged white wines by HPLC-DAD-ESI-MS(n). Online UV-vis spectra and pseudomolecular ions [(M + H)(+)] obtained by LC-MS supported the formation of some of the expected GRP hydrolysis products, mainly 2-S-glutathionyl-trans-caffeic acid (trans-GSCf), together with minor 2-S-(cysteinylglycyl)-trans-caftaric acid, 2-S-(γ-glutamylcysteinyl)-trans-caftaric acid, and 2-S-cysteinyl-trans-caftaric acid. On the basis of UV-vis and LC-MS(2) spectra, new GRP derivatives in aged white wines have been tentatively characterized for the first time as three monoethyl esters of GRP (GRP-Et) and also the cis isomers of GRP, GSCf, and some of the GRP-Et.

  13. Synthesis, characterization and crystal structure of (2RS,4R)-2-(2-hydroxy-3-methoxyphenyl)thiazolidine-4-carboxylic acid

    Science.gov (United States)

    Muche, Simon; Müller, Matthias; Hołyńska, Małgorzata

    2018-03-01

    The condensation reaction of ortho-vanillin and L-cysteine leads to formation of a racemic mixture of (2RS,4R)-2-(2-hydroxy-3-methoxyphenyl)thiazolidine-4-carboxylic acid and not, as reported in the available literature, to a Schiff base. The racemic mixture was fully characterized by 1D and 2D NMR techniques, ESI-MS and X-ray diffraction. Addition of ZnCl2 led to formation of crystals in form of colorless needles, suitable for X-ray diffraction studies. The measured crystals were identified as the diastereomer (2R,4R)-2-(2-hydroxy-3-methoxyphenyl)thiazolidine-4-carboxylic acid 1. The bulk material is racemic. Thiazolidine exists as zwitterion in solid state, as indicated by the crystal structure.

  14. (3R,6S,7aS-3-Phenyl-6-(phenylsulfanylperhydropyrrolo[1,2-c]oxazol-5-one

    Directory of Open Access Journals (Sweden)

    Anthony D. Woolhouse

    2009-05-01

    Full Text Available Molecules of the title compound [systematic name: (2R,5S,7S-2-phenyl-7-phenylsulfanyl-1-aza-3-oxabicyclo[3.3.0]octan-8-one], C18H17NO2S, form high quality crystals even though they are only packed using C—H...O(carbonyl and weak C—H...S interactions. The dihedral angle between the aromatic rings is 85.53 (5°. The fused rings adopt envelope and twist conformations.

  15. Synthesis and Characterization of Mixed Chalcogen Triangular Complexes with New Mo-3(mu(3)-S)(mu(2)-Se-2)(3)(4+) and M-3(mu(3)-S)mu(2)-Se)(3)(4+) (M = Mo, W) Cluster Cores

    DEFF Research Database (Denmark)

    Gushchin, Artem; Ooi, Bee Lean; Harris, Pernille

    2009-01-01

    In our pursuit of mixed chalcogen-bridged cluster complexes, solids of the compositions Mo3SSe6Br4 and W3SSe6Br4 were prepared using high-temperature synthesis from the elements. Treatment of Mo3SSe6Br4 with Bu4NBr in a vibration mill yielded (Bu4N)(3)([Mo-3(mu(3)-S)(mu(2)-Se-2)(3)Br-6]Br} (I). Its......), was isolated and its structure determined using X-ray crystallography. W3SSe6Br4 upon reaction with H3PO2 gave a mixture of all of the [W3SxSe4-x(H2O)(9)](4+) species. After repeated chromatography, crystals of {[W-3(mu(3)-S)(mu(2)-Se)(3)(H2O)(7)Cl--(2)](2)CB[6]}Cl-4 center dot 12H(2)O (IV) were crystallized...

  16. Enantioselective recognition of mandelic acid by a 3,6-dithiophen-2-yl-9H-carbazole-based chiral fluorescent bisboronic acid sensor.

    Science.gov (United States)

    Wu, Yubo; Guo, Huimin; James, Tony D; Zhao, Jianzhang

    2011-07-15

    We have prepared chiral fluorescent bisboronic acid sensors with 3,6-dithiophen-2-yl-9H-carbazole as the fluorophore. The thiophene moiety was used to extend the π-conjugation framework of the fluorophore in order to red-shift the fluorescence emission and, at the same time, to enhance the novel process where the fluorophore serves as the electron donor of the photoinduced electron transfer process (d-PET) of the boronic acid sensors; i.e., the background fluorescence of the sensor 1 at acidic pH is weaker compared to that at neutral or basic pH, in stark contrast to the typical a-PET boronic acid sensors (where the fluorophore serves as the electron acceptor of the photoinduced electron transfer process). The benefit of the d-PET boronic acid sensors is that the recognition of the hydroxylic acids can be achieved at acidic pH. We found that the thiophene moiety is an efficient π-conjugation linker and electron donor; as a result, the d-PET contrast ratio of the sensors upon variation of the pH is improved 10-fold when compared to the previously reported d-PET sensors without the thiophene moiety. Enantioselective recognition of tartaric acid was achieved at acid pH, and the enantioselectivity (total response K(D)I(F)(D)/K(L)I(F)(L)) is 3.3. The fluorescence enhancement (I(F)(Sample)/I(F)(Blank)) of sensor 1 upon binding with tartaric acid is 3.5-fold at pH 3.0. With the fluorescent bisboronic acid sensor 1, enantioselective recognition of mandelic acid was achieved for the first time. To the best of our knowledge, this is the first time that the mandelic acid has been enantioselectively recognized using a chiral fluorescent boronic acid sensor. Chiral monoboronic acid sensor 2 and bisboronic acid sensor 3 without the thiophene moiety failed to enantioselectively recognize mandelic acid. Our findings with the thiophene-incorporated boronic acid sensors will be important for the design of d-PET fluorescent sensors for the enantioselective recognition of

  17. First-principles study of low Miller index Ni3S2 surfaces in hydrotreating conditions.

    Science.gov (United States)

    Aray, Yosslen; Vega, David; Rodriguez, Jesus; Vidal, Alba B; Grillo, Maria Elena; Coll, Santiago

    2009-03-12

    Density functional theory (DFT) calculations combined with surface thermodynamic arguments and the Gibbs-Curie-Wulff equilibrium morphology formalism have been employed to explore the effect of the reaction conditions, temperature (T), and gas-phase partial pressures (PH2 and PH2S) on the stability of nickel sulfide (Ni3S2) surfaces. Furthermore, the strength and nature of chemical bonds for selected Ni3S2 surface cuts were investigated with the quantum theory of atoms in molecules methodology. A particular analysis of the electrostatic potential within this theoretical framework is performed to study the potential activity of nickel sulfide nanoparticles as hydrodesulfurization (HDS) catalysts. The calculated thermodynamic surface stabilities and the resulting equilibrium morphology model suggest that unsupported Ni3S2 nanoparticles mainly expose (111) and (111) type surface faces in HDS conditions. Analysis of the electrostatic potential mapped onto a selected electron density isocontour (0.001 au) on those expose surface reveals a poor potential reactivity toward electron-donating reagents (i.e., low Lewis acidity). Consequently, a very low attraction between coordinatively unsaturated active sites (Lewis sites) exposed at the catalytic particles and the S atoms coming from reagent polluting molecules does inactive these kinds of particles for HDS.

  18. Large-scale synthesis of double cauliflower-like Sb{sub 2}S{sub 3} microcrystallines by hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Lei [Key Laboratory for Soft Chemistry and Functional Materials, Ministry of Education (China); Xu, Hanyue [School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Han, Qiaofeng, E-mail: hanqiaofeng@njust.edu.cn [Key Laboratory for Soft Chemistry and Functional Materials, Ministry of Education (China); Wang, Xin [Key Laboratory for Soft Chemistry and Functional Materials, Ministry of Education (China)

    2013-09-25

    Highlights: •Highly uniform double cauliflower-like Sb{sub 2}S{sub 3} particles were synthesized via hydrothermal method. •Influence of reaction conditions on the morphology of the products was discussed. •Double cauliflower-like Sb{sub 2}S{sub 3} superstructures revealed broad spectrum response. -- Abstract: The double cauliflower-like Sb{sub 2}S{sub 3} superstructures assembled by nanorods were prepared using SbCl{sub 3} and Na{sub 2}S⋅9H{sub 2}O as raw materials, dodecyltrimethylammonium bromide (DTAB, C{sub 15}H{sub 31}BrN) as surfactant under acidic condition at 180 °C for 30 h. The structure, morphology and composition of the product were characterized by X-ray diffraction pattern (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and energy diffraction spectroscopy (EDS). The effect of reaction conditions including temperature, reaction time and surfactants on the sample morphology was discussed and a possible mechanism for the formation of cauliflower-like Sb{sub 2}S{sub 3} was proposed. The cauliflower-like Sb{sub 2}S{sub 3} microcrystallines revealed broad spectrum response, which may have a good application prospect in solar energy utilization and photoelectric conversion fields.

  19. Anthraquinone-2-sulfonic acid (AQ2S) is A Novel Neurotherapeutic Agent

    Science.gov (United States)

    Jackson, T C; Verrier, J D; Kochanek, P M

    2013-01-01

    Anthraquinone derivatives such as emodin have recently been shown to protect in models of beta amyloid β (Aβ) and tau aggregation-induced cell death. The mechanisms of action possibly involve preconditioning effects, anti-aggregation properties, and/or enhancing the phosphatidylinositol-3-kinase (PI3K)/AKT survival mechanism. We studied several natural (emodin, rhein, and aloin) and synthetic (AQ2S) anthraquinones, to screen for post-treatment therapeutic benefit in two models of neuronal death, namely hydrogen peroxide (H2O2) and staurosporine (STS)-induced injury. Treatment with emodin, rhein, or aloin failed to reduce H2O2 injury. Moreover, consistent with emodin behaving like a mild toxin, it exacerbated oxidative injury at the highest concentration used (50 μM) in our post-treatment paradigm, and potently inhibited AKT. In contrast, AQ2S was neuroprotective. It reduced H2O2 injury at 50 and 75 μM. In addition, AQ2S potently inhibited staurosporine (STS)-induced injury. The mechanisms of action involve caspase inhibition and AKT activation. However, blockade of AKT signaling with LY294002 failed to abolish AQ2S-mediated protection on the STS assay. This is the first study to report that AQ2S is a new neuroprotective compound and a novel caspase inhibitor. PMID:23303125

  20. Regioselective intramolecular ring closure of 2-amino-6-bromo-2,6-dideoxyhexono-1,4-lactones to 5- or 6-membered iminuronic acid analogues:synthesis of 1-deoxymannojirimycin and 2,5-dideoxy-2,5-imino-D-glucitol

    DEFF Research Database (Denmark)

    Malle, Birgitte Mølholm; Lundt, Inge; Wrodnigg, Tanja M.

    2008-01-01

    closure took place by 5-exo attack on the 5,6-epoxide leading to 2,5-dideoxy-2,5-imino-L-gulonic acid (9b), which was reduced to 2,5-dideoxy-2,5-imino-D-glucitol (9c). The method was further applied to 2-amino-6-bromo-2,6-dideoxy-D-galacto- as well as D-talo-1,4-lactones (14 and 15). However, only......-galacto- as well as L-talo-2-amino-6-bromo-2,6-dideoxy-1,4-lactones ent-14 and ent-15, reacted accordingly to give the D-galacto- and L-altro-1,5-iminuronic acid mimetics, (2S,3S,4R,5S)-3,4,5-trihydroxypipecolic acid (2,6-dideoxy-2,6-imino-L-galactonic acid, ent-16) and (2R,3S,4R,5S)-3,4,5-trihydroxypipecolic...

  1. Synthesis and crystal structures of two α-bromoamides, (2'R,1S,2S)-N(2-bromopropanoyl)-2-amino-1-phenylpropane-1,3-diol and (2'S,5S,6S)-N(2-bromopropanoyl)-5-amino-6-phenyl-2-oxo-1,3,2-dioxathiane

    International Nuclear Information System (INIS)

    English, R.B.; Liddell, R.J.; Whiteley, C.G.

    1987-01-01

    One pair of diastereomeric bromoamides, (2'R,1S,2S)- and (2'S,1S,2S)-N(2-bromopropanoyl)-2-amino-1-phenylpropane-1,3-diol have been synthesized from ethyl 2-bromopropionate and an optically active amino-diol. The crystal structures of both were determined from single-crystal X-ray analyses. Both compounds are orthorhombic with space group P2 1 2 1 2 1 with Z = 4 in a unit cell of dimensions a 22,124(5),b 12,812(5), and c 4,886(5)A and a 15,510(5), b 9,707(5), and c 9,457(5)A. The proton chemical shifts of the groups attached to the asymmetric centre C(2'), and consequently, the identification of the configuration of the molecules, were resolved with the help of high-resolution nuclear magnetic resonance

  2. Synthesis, physical and chemical properties of 2-((4-R-3-(morfolinomethylen-4H-1,2,4-triazole-5-ylthioacetic acid salts

    Directory of Open Access Journals (Sweden)

    R. О. Shcherbyna

    2017-04-01

    Full Text Available Today’s medicine and pharmacy undoubtedly need new and effective drugs. The 1,2,4-triazole derivatives occupy a special place among the wide variety of active organic compounds. This interest is caused primarily by high biological activity of these derivatives, low toxicity and high accessibility in terms of synthesis. Thus, drugs from 1,2,4-triazoles are known and are used extensively in medicine. It is important that a sufficiently large number of scientists-synthetics are paying attention on the heterocyclic system. Although a huge amount of information in the scientific literature is devoted to the 1,2,4-triazole derivatives, the 2-((4-R-3-(morfolinometylen-4H-1,2,4-triazole-5-ylthioacetic acid salts are virtually unexplored. The purpose of the work. Synthesis and establishing of the physical and chemical parameters of new 2-((4-R-3-(morfolinometylen-4H-1,2,4-triazole-5-ylthioacetic acid salts. Materials and methods. The study of physical and chemical properties of the obtained compounds was conducted by the methods that are listed in the State Pharmacopoeia of Ukraine 2.0. The melting point was defined on the device which determines the melting point MPA100. The elemental composition of the compounds was found on the analyzer Elementar Vario ЕL cube (CHNS . 1H NMR specters of obtained compounds were recorded by using a spectrometer Varian Mercury VX-200 (1H, 200 MHz and decrypted by a computer program SpinWorks 3.1.8. Chromatography-mass spectral studies were conducted on the gas-liquid chromatograph Agilent 1260 Infinity HPLC equipped with a mass spectrometer Agilent 6120 (ionization in electrospray (ESI. Results and discussion. As the source (starting compounds 2-((4-R-3-(morfolinometylen-4H-1,2,4-triazole-5-ylthioacetic acids (where, R = H, CH3, C2H5, C6H5, NH2 were taken. Further, by the action of ammonia hydroxide, sodium and potassium hidrogen carbonates, piperidine, morpholine, methylamine, monoethanolamine and tributylamine in

  3. The role of leucine in isoprenoid metabolism. Incorporation of [3-13C]leucine and of [2-3H,4-14C]-β,β-dimethyl-acrylic acid into phytosterols by tissue cultures of Andrographis paniculata

    International Nuclear Information System (INIS)

    Anastasis, P.; Freer, I.; Overton, K.; Rycroft, D.; Singh, S.B.

    1985-01-01

    [3- 13 C]Leucine is incorporated into phytosterols by tissue cultures of Andrographis paniculata by breakdown to acetyl-CoA and its subsequent incorporation via (3S)-3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) and mevalonic acid; [2- 3 H,4- 14 C]-β,β-dimethylacrylic acid also is not incorporated intact. (author)

  4. MLS/Aura Level 2 Nitric Acid (HNO3) Mixing Ratio V003 (ML2HNO3) at GES DISC

    Data.gov (United States)

    National Aeronautics and Space Administration — ML2HNO3 is the EOS Aura Microwave Limb Sounder (MLS) standard product for nitric acid derived from radiances measured by the 240 GHz radiometer at and below 10 hPa,...

  5. MLS/Aura Level 2 Nitric Acid (HNO3) Mixing Ratio V004 (ML2HNO3) at GES DISC

    Data.gov (United States)

    National Aeronautics and Space Administration — ML2HNO3 is the EOS Aura Microwave Limb Sounder (MLS) standard product for nitric acid derived from radiances measured by the 240 GHz radiometer at and below 10 hPa,...

  6. A new and concise strategy to the enantioselective synthesis of (S)-2-amino-4-oxo-4-(pyridine-2-yl) butanoic acid from aspartic acid

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Evanoel Crizanto de; Souza, Carolina C. de; Maior, Marta C.L.S.; Costa, Paulo R.R., E-mail: prrcosta@ism.com.b [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Centro de Ciencias da Saude. Nucleo de Pesquisas de Produtos Naturais; Lima, Paulo G. de [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica; Dias, Ayres G. [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. de Quimica

    2010-07-01

    The alpha-amino acid (S)-5 was synthesized using in the key step a chemoselective nucleophilic substitution between a diester derived from L-aspartic acid and 2-lithium pyridine. The overall yield (13%, 5 steps) was similar to those previously described by our group for the R isomer (the first exogen full agonist of the NMDA receptors) from D-mannitol (12%, 10 steps) and by Lovey and Copper for the racemic synthesis (17%, 5 steps). (author)

  7. Validation of a multi-analyte HPLC-DAD method for determination of uric acid, creatinine, homovanillic acid, niacinamide, hippuric acid, indole-3-acetic acid and 2-methylhippuric acid in human urine.

    Science.gov (United States)

    Remane, Daniela; Grunwald, Soeren; Hoeke, Henrike; Mueller, Andrea; Roeder, Stefan; von Bergen, Martin; Wissenbach, Dirk K

    2015-08-15

    During the last decades exposure sciences and epidemiological studies attracts more attention to unravel the mechanisms for the development of chronic diseases. According to this an existing HPLC-DAD method for determination of creatinine in urine samples was expended for seven analytes and validated. Creatinine, uric acid, homovanillic acid, niacinamide, hippuric acid, indole-3-acetic acid, and 2-methylhippuric acid were separated by gradient elution (formate buffer/methanol) using an Eclipse Plus C18 Rapid Resolution column (4.6mm×100mm). No interfering signals were detected in mobile phase. After injection of blank urine samples signals for the endogenous compounds but no interferences were detected. All analytes were linear in the selected calibration range and a non weighted calibration model was chosen. Bias, intra-day and inter-day precision for all analytes were below 20% for quality control (QC) low and below 10% for QC medium and high. The limits of quantification in mobile phase were in line with reported reference values but had to be adjusted in urine for homovanillic acid (45mg/L), niacinamide 58.5(mg/L), and indole-3-acetic acid (63mg/L). Comparison of creatinine data obtained by the existing method with those of the developed method showing differences from -120mg/L to +110mg/L with a mean of differences of 29.0mg/L for 50 authentic urine samples. Analyzing 50 authentic urine samples, uric acid, creatinine, hippuric acid, and 2-methylhippuric acid were detected in (nearly) all samples. However, homovanillic acid was detected in 40%, niacinamide in 4% and indole-3-acetic acid was never detected within the selected samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Comparative acute nephrotoxicity of salicylic acid, 2,3-dihydroxybenzoic acid, and 2,5-dihydroxybenzoic acid in young and middle aged Fischer 344 rats.

    Science.gov (United States)

    McMahon, T F; Stefanski, S A; Wilson, R E; Blair, P C; Clark, A M; Birnbaum, L S

    1991-03-11

    Experimental evidence suggests that the oxidative metabolites 2,3- and 2,5-dihydroxybenzoic acid (DIOH) may be responsible for the nephrotoxicity of salicylic acid (SAL). In the present study, enzymuria in conjunction with glucose (GLU) and protein (PRO) excretion were used as endpoints to compare the relative nephrotoxicity of SAL with 2,3- and 2,5-DIOH. In addition, the effect of age on enzymuria and GLU and PRO excretion following treatment with SAL or 2,3- and 2,5-DIOH was investigated because the elderly are at greater risk for SAL-induced nephrotoxicity. Three and 12-month male Fischer 344 rats were administered either no treatment, vehicle, SAL, 2,3-DIOH, or 2,5-DIOH at 500 mg/kg p.o. in 5 ml/kg corn oil/DMSO (5:1). Effects of these treatments on functional integrity of renal tissue was assessed from 0--72 h after dosing by measurement of urinary creatinine, GLU, and PRO, as well as excretion of proximal and distal tubular renal enzymes. Enzymes measured as indicators of proximal tubular damage were N-acetyl-beta-glucosaminidase (NAG), gamma glutamyltransferase (GGT), alanine aminotransferase (ALT), and alkaline phosphatase (AP), while urinary lactate dehydrogenase (LD) and aspartate aminotransferase (AST) were measured as indicators of distal tubular damage. In comparison to 3-month vehicle-treated rats, 2,3- and 2,5-DIOH caused a significant increase between 0-8 h in excretion of urinary GLU and activities of AST, NAG, and LD, with peak effects occurring between 4-8 h. Toxic effects of either metabolite were not evident beyond 24 h, and toxicity of 2,5-DIOH was significantly greater in comparison to 2,3-DIOH. SAL treatment resulted in similar effects on enzymuria as well as GLU and PRO excretion, but peak effects did not occur until 16-24 h, and often persisted until 72 h after dosing. Maximal enzymuria in response to SAL treatment was significantly greater in 12- vs. 3-month rats for AST, NAG, and LD. In response to 2,3-DIOH treatment, the maximal

  9. NMR Spectroscopic Characterization of Methylcobalt(III) Compounds with Classical Ligands. Crystal Structures of [Co(NH(3))(5)(CH(3))]S(2)O(6), trans-[Co(en)(2)(NH(3))(CH(3))]S(2)O(6) (en = 1,2-Ethanediamine), and [Co(NH(3))(6)]-mer,trans-[Co(NO(2))(3)(NH(

    DEFF Research Database (Denmark)

    Kofod, Pauli; Harris, Pernille; Larsen, Sine

    1997-01-01

    magnetic resonance spectroscopy and by absorption spectroscopy. Single-crystal X-ray structure determinations at 122.0(5) K were performed on [Co(NH(3))(5)(CH(3))]S(2)O(6) (1), trans-[Co(en)(2)(NH(3))(CH(3))]S(2)O(6) (2), and [Co(NH(3))(6)]-mer,trans-[Co(NO(2))(3)(NH(3))(2)(CH(3))](2)-trans-[Co(NO(2...

  10. Oral omega-3 fatty acids treatment in computer vision syndrome related dry eye.

    Science.gov (United States)

    Bhargava, Rahul; Kumar, Prachi; Phogat, Hemant; Kaur, Avinash; Kumar, Manjushri

    2015-06-01

    To assess the efficacy of dietary consumption of omega-3 fatty acids (O3FAs) on dry eye symptoms, Schirmer test, tear film break up time (TBUT) and conjunctival impression cytology (CIC) in patients with computer vision syndrome. Interventional, randomized, double blind, multi-centric study. Four hundred and seventy eight symptomatic patients using computers for more than 3h per day for minimum 1 year were randomized into two groups: 220 patients received two capsules of omega-3 fatty acids each containing 180mg eicosapentaenoic acid (EPA) and 120mg docosahexaenoic acid (DHA) daily (O3FA group) and 236 patients received two capsules of a placebo containing olive oil daily for 3 months (placebo group). The primary outcome measure was improvement in dry eye symptoms and secondary outcome measures were improvement in Nelson grade and an increase in Schirmer and TBUT scores at 3 months. In the placebo group, before dietary intervention, the mean symptom score, Schirmer, TBUT and CIC scores were 7.5±2, 19.9±4.7mm, 11.5±2s and 1±0.9 respectively, and 3 months later were 6.8±2.2, 20.5±4.7mm, 12±2.2s and 0.9±0.9 respectively. In the O3FA group, these values were 8.0±2.6, 20.1±4.2mm, 11.7±1.6s and 1.2±0.8 before dietary intervention and 3.9±2.2, 21.4±4mm, 15±1.7s, 0.5±0.6 after 3 months of intervention, respectively. This study demonstrates the beneficial effect of orally administered O3FAs in alleviating dry eye symptoms, decreasing tear evaporation rate and improving Nelson grade in patients suffering from computer vision syndrome related dry eye. Copyright © 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  11. Slc3a2 Mediates Branched-Chain Amino-Acid-Dependent Maintenance of Regulatory T Cells

    Directory of Open Access Journals (Sweden)

    Kayo Ikeda

    2017-11-01

    Full Text Available Summary: Foxp3+ regulatory T (Treg cells, which suppress immune responses, are highly proliferative in vivo. However, it remains unclear how the active replication of Treg cells is maintained in vivo. Here, we show that branched-chain amino acids (BCAAs, including isoleucine, are required for maintenance of the proliferative state of Treg cells via the amino acid transporter Slc3a2-dependent metabolic reprogramming. Mice fed BCAA-reduced diets showed decreased numbers of Foxp3+ Treg cells with defective in vivo proliferative capacity. Mice lacking Slc3a2 specifically in Foxp3+ Treg cells showed impaired in vivo replication and decreased numbers of Treg cells. Slc3a2-deficient Treg cells showed impaired isoleucine-induced activation of the mTORC1 pathway and an altered metabolic state. Slc3a2 mutant mice did not show an isoleucine-induced increase of Treg cells in vivo and exhibited multi-organ inflammation. Taken together, these findings demonstrate that BCAA controls Treg cell maintenance via Slc3a2-dependent metabolic regulation. : Treg cells regulate excess immune responses and are highly proliferative in vivo. Ikeda et al. find that branched-chain amino acids (BCAAs are essentially required to maintain expansion and the suppressive capacity of Treg cells via Slc3a2 and mTORC1. Keywords: Treg cells, amino acids, immunometabolism, immune regulation, transporter

  12. Attempts to Synthesize 3-acyl-4-hydroxycoumarins from Meldrum’s acid -- and Related Chemistry

    OpenAIRE

    Ye, Fengbin; Tropp, Kristin; Yu, Yiting

    2007-01-01

    We start our synthetic work with the acylation of Meldrum’s acid to get three different 5-acyl Meldrum’s acids. These compounds are attacked by various nucleophiles containing different hetero atoms to obtain β-ketoesters, β-ketoamides and the corresponding β-keto-phosphorus compounds respectively. New β-ketoamides could be synthesized and characterized. The reaction of acylated Meldrum’s acid and diphenylphosphine did not lead to the expected β-keto-phosphide compound, but the resulting prod...

  13. 2-(3-Methylsulfanyl-5-propyl-1-benzofuran-2-ylacetic acid

    Directory of Open Access Journals (Sweden)

    Uk Lee

    2009-05-01

    Full Text Available The title compound, C14H16O3S, was prepared by alkaline hydrolysis of ethyl 2-(3-methylsulfanyl-5-propyl-1-benzofuran-2-ylacetate. In the crystal structure, the carboxyl groups are involved in intermolecular O—H...O hydrogen bonds, which link the molecules into centrosymmetric dimers. These dimers are further packed into stacks along the a axis by weak C—H...π interactions.

  14. Technetium(V)-nitrido complexes of dithiocarbazic acid derivatives. Reactivity of [Tc≡N]2+ core towards Schiff bases derived from S-methyl dithiocarbazate. Crystal structures of [S-methyl 3-(2-hydroxyphenyl-methylene) dithiocarbazato]intrido(triphenylphosphine)technetium(V) and bis(S-methyl 3-isopropylidenedithiocarbazato)nitridotechnetium(V)

    International Nuclear Information System (INIS)

    Marchi, A.; Duatti, A.; Rossi, R.; Magon, L.; Bertolasi, V.; Ferretti, V.; Gilli, G.; Pasqualini, R.

    1988-01-01

    As a potential alternative approach to lipophilic square-pyramidal technetium complexes, we investigate here the synthesis of new Tcsup(V) complexes, containing the [Tc''ident to''N] 2+ core, with bi- and tri-dentate Schiff bases derived from S-methyl dithiocarbazate, NH 2 NHC(=S)SCH 3 . Square-pyramidal complexes having an apical Tcsup(V) ≡ N group, with bis(quinoline-8-thiolato), [TcN(C 9 H 6 NS) 2 ], and bis(diethyldithiocarbamate), [TcN(S 2 CNEt 2 ) 2 ], have been reported. In this paper, we report the synthesis and characterization of a series of technetium(V)-nitrido complexes with the ligands illustrated, obtained by reduction of the technetium(VI) complex [TcNCl 4 ] - or by ligand substitution of the Tcsup(V) complex [TcNCl 2 (PPh 3 ) 2 ]. We discuss also the crystal structures of the complexes [TcNL 1 (PPh 3 )] [H 2 L 1 = S-methyl 3-(2-hydroxy-phenylmethylene)dithiocarbazate] and [TcN(L 12 ) 2 ] (HL 12 S-methyl 3-isopropylidenedithiocarbazate. (author)

  15. Mechanochemical synthesis of ultrafine Ce2S3 powder

    International Nuclear Information System (INIS)

    Tsuzuki, T.; McCormick, P.G.

    1998-01-01

    Full text: Rare earth sulphides have been receiving an increasing attraction for various applications including infrared window materials and magneto-optical devices. In particular, Ce 2 S 3 has been under intensive study for use as a red pigment to replace toxic cadmium sulfoselenide. The conventional method for synthesising Ce 2 S 3 is the sulphidization of the element or sesquioxide with hydrogen sulphide gas. However, the method usually requires a high-temperature process (>1000 deg C), and hence coarse particles larger than the optimal size of ∼ 2 S 3 powder by mechanochemical processing using X-ray diffraction spectroscopy, BET surface area analysis and transmission electron microscopy. Mechanical milling of the mixture of a cerium salt and an alkali/alkali-earth sulphide powders led to a solid state displacement reaction in a steady-state manner, forming Ce 2 S 3 nanoparticles in a salt by-product matrix. After a simple washing process to remove the salt by-product, ultrafine Ce 2 S 3 particles with sizes of 20 - 200 nm having an orthorhombic structure were obtained. Using a diluent and mechanically alloyed CaS nanoparticles in the starting powder, particles of only a cubic γ-Ce 2 S 3 phase with sizes of 10 - 80 nm were formed

  16. Supersymmetric AdS3, AdS2 and bubble solutions

    International Nuclear Information System (INIS)

    Gauntlett, Jerome P.; Waldram, Daniel; Kim, Nakwoo

    2007-01-01

    We present new supersymmetric AdS 3 solutions of type IIB supergravity and AdS 2 solutions of D = 11 supergravity. The former are dual to conformal field theories in two dimensions with N = (0, 2) supersymmetry while the latter are dual to conformal quantum mechanics with two supercharges. Our construction also includes AdS 2 solutions of D = 11 supergravity that have non-compact internal spaces which are dual to three-dimensional N = 2 superconformal field theories coupled to point-like defects. We also present some new bubble-type solutions, corresponding to BPS states in conformal theories, that preserve four supersymmetries

  17. Fabrication of In2O3@In2S3 core-shell nanocubes for enhanced photoelectrochemical performance

    Science.gov (United States)

    Li, Haohua; Chen, Cong; Huang, Xinyou; Leng, Yang; Hou, Mengnan; Xiao, Xiaogu; Bao, Jie; You, Jiali; Zhang, Wenwen; Wang, Yukun; Song, Juan; Wang, Yaping; Liu, Qinqin; Hope, Gregory A.

    2014-02-01

    Herein, we report the facile synthesis of In2O3@In2S3 core-shell nanocubes and their improved photoelectrochemical property. In2O3@In2S3 core-shell nanocubes are grown on a F-doped SnO2 (FTO) glass substrate by a two-step process, which involves the electrodeposition of In2O3 nanocubes and a subsequent ion-exchange treatment. The improved light-harvesting ability and the suitable band alignment of the In2O3@In2S3 core-shell nanocubes generate a remarkable photocurrent density of 6.19 mA cm-2 (at 0 V vs. Ag/AgCl), which is substantially higher than the pristine In2O3 nanocubes. These results provide a new insight into the design of a high-performance photoanode for photoelectrochemical water splitting.

  18. Nitric acid titration in the presence of UO2(NO3)2, Th(NO3)4, U(NO3)4 or Zr(NO3)4

    International Nuclear Information System (INIS)

    Nakashima, T.; Lieser, K.H.

    1986-01-01

    Procedures are described for titration of HNO 3 in presence of UO 2 2+ , Th 4+ , U 4+ and Zr 4+ without formation of interfering precipitates. In the first step the hydrolysable ions are masked by addition of complexing agents and in the second step the acid is titrated by NaOH as usual. (orig.)

  19. Facile fabrication of Bi_2S_3/SnS_2 heterojunction photocatalysts with efficient photocatalytic activity under visible light

    International Nuclear Information System (INIS)

    Gao, Xiaomin; Huang, Guanbo; Gao, Haihuan; Pan, Cheng; Wang, Huan; Yan, Jing; Liu, Yu; Qiu, Haixia; Ma, Ning; Gao, Jianping

    2016-01-01

    In this work, Bi_2S_3/SnS_2 heterojunction photocatalysts were prepared by combining a hydrothermal technique and a facile in situ growth method. The nanocomposites were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, inductively coupled plasma spectroscopy, X-ray photoelectron spectroscopy, UV–Vis diffusion reflectance spectroscopy and room-temperature photoluminescence spectra. Their photocatalytic performances were evaluated by degrading methyl orange (MO) in aqueous solution (50 mg/L) under visible light (λ > 420 nm) irradiation. It was found that when the mass percentage of Bi_2S_3 in Bi_2S_3/SnS_2 was 7.95 wt%, the as-prepared Bi_2S_3/SnS_2 nanocomposite showed the best photocatalytic activity for the degradation of MO. The highly improved performance of the Bi_2S_3/SnS_2 nanocomposite was mainly ascribed to the efficient charge separation. - Highlights: • Facile fabrication of novel Bi_2S_3/SnS_2 heterojunction photocatalysts. • High-performance photocatalyst for the degradation of organic pollutants. • Good recyclability of catalyst without photo-corrosion. • The photocatalytic mechanism was proposed.

  20. Chemically deposited In{sub 2}S{sub 3}-Ag{sub 2}S layers to obtain AgInS{sub 2} thin films by thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Lugo, S. [Universidad Autonoma de Nuevo Leon, UANL, Fac. de Ciencias Quimicas, Av. Universidad S/N Ciudad Universitaria San Nicolas de Los Garza Nuevo Leon, C.P. 66451 (Mexico); Pena, Y., E-mail: yolapm@gmail.com [Universidad Autonoma de Nuevo Leon, UANL, Fac. de Ciencias Quimicas, Av. Universidad S/N Ciudad Universitaria San Nicolas de Los Garza Nuevo Leon, C.P. 66451 (Mexico); Calixto-Rodriguez, M. [Centro de Investigacion en Energia-Universidad Nacional Autonoma de Mexico, 62580, Temixco, Morelos (Mexico); Lopez-Mata, C. [Instituto Tecnologico de Chetumal, Av. Insurgentes No. 330, C.P. 77013, Col. David Gustavo Gtz., Chetumal, Quintana Roo (Mexico); Ramon, M.L. [Centro de Investigacion en Energia-Universidad Nacional Autonoma de Mexico, 62580, Temixco, Morelos (Mexico); Gomez, I.; Acosta, A. [Universidad Autonoma de Nuevo Leon, UANL, Fac. de Ciencias Quimicas, Av. Universidad S/N Ciudad Universitaria San Nicolas de Los Garza Nuevo Leon, C.P. 66451 (Mexico)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer We obtained polycrystalline silver indium sulfide thin films through the annealing of chemically deposited In{sub 2}S{sub 3}-Ag{sub 2}S films. Black-Right-Pointing-Pointer According to XRD chalcopyrite structure of AgInS{sub 2} was obtained. Black-Right-Pointing-Pointer AgInS{sub 2} thin film has a band gap of 1.86 eV and a conductivity value of 1.2 Multiplication-Sign 10{sup -3} ({Omega} cm){sup -1}. - Abstract: AgInS{sub 2} thin films were obtained by the annealing of chemical bath deposited In{sub 2}S{sub 3}-Ag{sub 2}S layers at 400 Degree-Sign C in N{sub 2} for 1 h. According to the XRD and EDX results the chalcopyrite structure of AgInS{sub 2} has been obtained. These films have an optical band gap, E{sub g}, of 1.86 eV and an electrical conductivity value of 1.2 Multiplication-Sign 10{sup -3} ({Omega} cm){sup -1}.

  1. Synthesis and conformational analysis of hybrid α/β-dipeptides incorporating S-glycosyl-β(2,2)-amino acids.

    Science.gov (United States)

    García-González, Iván; Mata, Lara; Corzana, Francisco; Jiménez-Osés, Gonzalo; Avenoza, Alberto; Busto, Jesús H; Peregrina, Jesús M

    2015-01-12

    We synthesized and carried out the conformational analysis of several hybrid dipeptides consisting of an α-amino acid attached to a quaternary glyco-β-amino acid. In particular, we combined a S-glycosylated β(2,2)-amino acid and two different types of α-amino acid, namely, aliphatic (alanine) and aromatic (phenylalanine and tryptophan) in the sequence of hybrid α/β-dipeptides. The key step in the synthesis involved the ring-opening reaction of a chiral cyclic sulfamidate, inserted in the peptidic sequence, with a sulfur-containing nucleophile by using 1-thio-β-D-glucopyranose derivatives. This reaction of glycosylation occurred with inversion of configuration at the quaternary center. The conformational behavior in aqueous solution of the peptide backbone and the glycosidic linkage for all synthesized hybrid glycopeptides was analyzed by using a protocol that combined NMR experiments and molecular dynamics with time-averaged restraints (MD-tar). Interestingly, the presence of the sulfur heteroatom at the quaternary center of the β-amino acid induced θ torsional angles close to 180° (anti). Notably, this value changed to 60° (gauche) when the peptidic sequence displayed aromatic α-amino acids due to the presence of CH-π interactions between the phenyl or indole ring and the methyl groups of the β-amino acid unit. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. 2-(5-Fluoro-3-methylsulfanyl-1-benzofuran-2-ylacetic acid

    Directory of Open Access Journals (Sweden)

    Hong Dae Choi

    2009-08-01

    Full Text Available The title compound, C11H9FO3S, was prepared by alkaline hydrolysis of ethyl 2-(5-fluoro-3-methylsulfanyl-1-benzofuran-2-ylacetate. In the crystal structure, the carboxyl groups are involved in intermolecular O—H...O hydrogen bonds, which link the molecules into centrosymmetric dimers. These dimers are further packed into stacks along the b axis by intermolecular C—H...O and C—H...F interactions.

  3. Free radicals in dicarboxylic acids: an e.s.r. study of radical conversions in γ-irradiated single crystals of glutaric acid and glutaric-2,2,4,4-d4 acid

    International Nuclear Information System (INIS)

    Bergene, R.; Minegishi, A.; Riesz, P.

    1980-01-01

    The γ-radiation-induced free radicals in single crystals of glutaric acid and glutaric-2,2,4,4-d 4 acid were studied in the temperature range 77-300 K by e.s.r. techniques. At 77 K the decarboxylation radical and the anion are stabilized. At higher temperatures the decarboxylation radical is found to be converted into a hydrogen abstraction radical with an activation energy of 6.3 +- 0.5 kcal/mole for the non-deuterated crystal. This radical is stable at room temperature. The anion seems to be converted to a unidentified intermediate radical which in turn is converted to the σ-acyl radical. An analysis of the g-value anisotropy and of the 13 C hyperfine splitting variation for this radical in the deuterated crystal is consistent with the assigned radical structure. By heat treatment the σ-acyl radical is converted to another form of the hydrogen abstraction radical with an activation energy of 9.6 +- 0.6 kcal/mole in the deuterated crystal. U.V.-light (lambda= 254 nm) transforms one of the room temperature radicals into the other. (author)

  4. Acetylsalicylic Acid Daily vs Acetylsalicylic Acid Every 3 Days in Healthy Volunteers: Effect on Platelet Aggregation, Gastric Mucosa, and Prostaglandin E2 Synthesis.

    Science.gov (United States)

    Ferreira, Plinio Minghin Freitas; Gagliano-Jucá, Thiago; Zaminelli, Tiago; Sampaio, Marinalva Ferreira; Blackler, Rory Willian; Trevisan, Miriam da Silva; Novaes Magalhães, Antônio Frederico; De Nucci, Gilberto

    2016-07-01

    Substantial platelet inhibition was observed 3 days after a single administration of acetylsalicylic acid 81 mg to healthy volunteers. Here we investigate prostaglandin E2 (PGE2 ) antrum concentrations and gastrointestinal symptoms in two treatment groups: one receiving losartan and acetylsalicylic acid every day and the other receiving losartan every day and acetylsalicylic acid every 3 days. Twenty-eight healthy volunteers from both sexes received either 50 mg losartan and acetylsalicylic acid 81 mg daily or 50 mg losartan and acetylsalicylic acid 81 every 3 days with placebo on the other days. Therapy was delivered for 30 days for both groups. Gastric endoscopy was performed before and after treatment period. Biopsies were collected for PGE2 quantification. Platelet function tests were carried out before and during treatment and TXB2 release on platelet rich plasma was measured. The every 3 day low-dose acetylsalicylic acid regimen produced complete inhibition of platelet aggregation compared to the daily treatment. Thromboxane B2 release was substantially abolished for both groups during treatment. There was no significant difference on the endoscopic score of both treatment groups after the 30-day treatment (P = .215). There was over 50% suppression of antrum PGE2 content on volunteers receiving acetylsalicylic acid daily (P = .0016), while for the every 3 day dose regimen there was no significant difference between pre and post-treatment antrum PGE2 dosages (P = .4193). Since PGE2 is involved in gastric healing, we understand that this new approach could be safer and as efficient as the standard daily therapy on a long-term basis. © 2015, The American College of Clinical Pharmacology.

  5. Crystal structure of the mixed-metal trisulfide BaCu1/3Ta2/3S3

    Directory of Open Access Journals (Sweden)

    Kejun Bu

    2017-05-01

    Full Text Available The mixed-metal title compound, BaCu1/3Ta2/3S3 [barium copper(II tantalum(V trisulfide], was prepared through solid-state reactions. The crystal structure adopts the BaTaS3 structure type and consists of face-sharing [MS6] (M = Ta,Cu octahedra (point-group symmetry -3m. that are condensed into infinite chains along [001]. Adjacent chains are linked through the barium cations (site symmetry -6m2, which exhibit a coordination number of twelve. The M site is occupied by 2/3 of TaV and 1/3 of CuII, whereby the average M—S distances are slightly longer than those of ordered BaTaS3. The classical charge balance of the title compound can be represented by [Ba2+] [(Ta/Cu4+] [S2−]3.

  6. Electron Excitation Rate Coefficients for Transitions from the IS21S Ground State to the 1S2S1,3S and 1S2P1,3P0 Excited States of Helium

    Science.gov (United States)

    Aggarwal, K. M.; Kingston, A. E.; McDowell, M. R. C.

    1984-03-01

    The available experimental and theoretical electron impact excitation cross section data for the transitions from the 1s2 1S ground state to the 1s2s 1,3S and 1s2p 1,3P0 excited states of helium are assessed. Based on this assessed data, excitation rate coefficients are calculated over a wide electron temperature range below 3.0×106K. A comparison with other published results suggests that the rates used should be lower by a factor of 2 or more.

  7. Modification of Turen Bentonite with AlCl3 for Esterification of Palmitic Acid

    Directory of Open Access Journals (Sweden)

    Abdulloh Abdulloh

    2014-03-01

    Full Text Available Natural Turen bentonite has been modified and applied as catalyst for palmitic acid esterification. Modification of natural Turen bentonite was conducted by cation exchange method using AlCl3 solution. Catalyst characterization was performed on X-ray Fluoroscence, X-ray Diffraction, nitrogen adsorption-desorption and infrared spectroscopy techniques. The catalytic activity test in the esterification reaction of palmitic acid with methanol was conducted by bath at 65 °C with a variation of reaction time of 1, 2, 3, 4 and 5 h. Catalytic activity has been observed qualitatively using GC-MS and quantitatively by changes in acid number. The analysis showed the formation of Al3+-bentonite. Observation on the elements has shown that the presence of calcium decreased from 10.2% to 4.17%, with an increase of aluminium content from 9.9% to 13%. Diffraction line at 2θ 5.7379º became 5.6489º, along with changes in d-spacing of 15.3895 Å to 15.6319 Å. The surface area increased from 83.78 m2/g to 91.26 m2/g, while Brönsted acid sites increased from 10.2 µmol/g to 67.5 µmol/g and Lewis acid sites increased from 94.9 µmol/g to 132 µmol/g. Furthermore, Al3+-bentonite has showed as active catalyst in the esterification reaction of palmitic acid with palmitic acid with conversion of 78.78% for 5 h. © 2014 BCREC UNDIP. All rights reservedReceived: 24th September 2013; Revised: 31st December 2013; Accepted: 26th January 2014[How to Cite: Abdulloh, A., Maryam, S., Aminah, N.S., Triyono, T., Trisunaryanti, W., Mudasir, M., Prasetyoko, D. (2014. Modification of Turen’s Bentonite with AlCl3 for Esterification of Palmitic Acid. Bulletin of Chemical Reaction Engineering & Catalysis, 9 (1: 66-73. (doi:10.9767/bcrec.9.1.5513.66-73][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.9.1.5513.66-73

  8. Mid-infrared emissions of Pr{sup 3+}-doped GeS{sub 2}–Ga{sub 2}S{sub 3}–CdI{sub 2} chalcohalide glasses

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Chunfeng [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and precision Mechanics, Chinese Academy of Science (CAS), Xi’an, Shaanxi 710119 (China); Guo, Haitao, E-mail: guoht_001@opt.ac.cn [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and precision Mechanics, Chinese Academy of Science (CAS), Xi’an, Shaanxi 710119 (China); Xu, Yantao; Hou, Chaoqi; Lu, Min [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and precision Mechanics, Chinese Academy of Science (CAS), Xi’an, Shaanxi 710119 (China); He, Xin [School of Applied Physics and Materials, Wuyi University, Jiangmen, Guangdong 529020 (China); Wang, Pengfei; Li, Weinan [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and precision Mechanics, Chinese Academy of Science (CAS), Xi’an, Shaanxi 710119 (China); Peng, Bo, E-mail: bpeng@opt.ac.cn [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and precision Mechanics, Chinese Academy of Science (CAS), Xi’an, Shaanxi 710119 (China)

    2014-12-15

    Graphical abstract: ∼4.6 μm mid-infrared fluorescence emission from Pr{sup 3+} in the sulfide glass is successfully observed at room temperature excited by a 2.01 μm Tm{sup 3+}:YAG ceramic laser system. - Highlights: • Serial Pr{sup 3+}-doped GeS{sub 2}–Ga{sub 2}S{sub 3}–CdI{sub 2} chalcohalide glasses were synthesized. • ∼4.6 μm mid-infrared fluorescence from Pr{sup 3+} was observed at room temperature. • The compositional dependence of luminescence properties was studied. • Radiative properties have been determined using the Judd–Ofelt theory. - Abstract: For elucidation of the glass composition’s influence on the spectroscopic properties in the chalcohalide system and the discovery of a new material for applications in mid-infrared fiber-lasers, a serial Pr{sup 3+}-doped (100 − x)(0.8GeS{sub 2}·0.2Ga{sub 2}S{sub 3})xCdI{sub 2} (x = 5, 10, 15 and 20) chalcohalide glasses were prepared. ∼4.6 μm mid-infrared fluorescence emission from Pr{sup 3+} in the sulfide glass is successfully observed at room temperature excited by a 2.01 μm Tm{sup 3+}:YAG ceramic laser system, and the effective line-width of fluorescence band is 106–227 nm. Intense compositional dependence of mid-infrared emissions is found. The radiative rates of Pr{sup 3+} ions in these glasses were calculated by using the Judd–Ofelt theory.

  9. Mass spectrometric study of Nd2S3 vaporization

    International Nuclear Information System (INIS)

    Fenochka, B.V.

    1987-01-01

    The authors conduct a mass-spectrometric study of neodymium(III) sulfide vaporization. The chemical composition of the samples was stoichiometric and the samples were vaporized from tantalum effusion cells. When the vapor over Nd 2 S 3 is ionized by electrons the mass spectra shows monovalent cations of Nd, S, NdS, and NdO. The enthalpy of vaporization if Nd atoms from Nd 2 S 3 at average experimental temperatures and the standard enthalpy of reaction is shown. Also presented is the enthalpy of vaporization of NdS molecules from Nd 2 S 3 at average experimental temperatures and the standard enthalpy of reaction

  10. O(αs2) and O(αs3) heavy flavor contributions to transversity at Q2 >> m2

    International Nuclear Information System (INIS)

    Bluemlein, Johannes; Klein, Sebastian; Toedtli, Beat

    2009-09-01

    In deep-inelastic processes the heavy flavor Wilson coefficients factorize for Q 2 >>m 2 into the light flavor Wilson coefficients of the corresponding process and the massive operator matrix elements (OMEs). We calculate the O(α s 2 ) and O(α s 3 ) massive OME for the flavor non-singlet transversity distribution. At O(α s 2 ) the OME is obtained for general values of the Mellin variable N, while at O(α s 3 ) the moments N=1 to 13 are computed. The terms ∝ T F of the 3.loop transversity anomalous dimension are obtained and results in the literature are confirmed. We discuss the relation of these contributions to the Soffer bound for transversity. (orig.)

  11. Influence of hydroxybenzoic acids on the adsorption of Eu(III) onto α,γ-Al_2O_3 particles in mildly acidic conditions: A macroscopic and spectroscopic study

    International Nuclear Information System (INIS)

    Moreau, Pauline; Colette-Maatouk, Sonia; Gareil, Pierre; Reiller, Pascal E.

    2016-01-01

    The influence of hydroxybenzoic acids (HAH_n), namely p-hydroxybenzoic acid (4-hydroxybenzoic acid, HPhbH) and protocatechuic acid (3,4-dihydroxybenzoic acid, HProtoH_2), on the adsorption of europium(III) onto α,γ-Al_2O_3 particles is studied as a function of acid concentration. After measuring the adsorption edge of the Eu(III)/α,γ-Al_2O_3 binary system, and using the previously studied binary component system Eu(III)/HAH_n—Moreau et al. (2015) Inorg. Chim. Acta432, 81—, and HAH_n/α,γ-Al_2O_3—Moreau et al. (2013) Colloids Surf. A435, 97—, it is evidenced that HPhbH does not enhance Eu(III) adsorption onto α,γ-Al_2O_3 in the Eu(III)/HPhbH/α,γ-Al_2O_3 ternary system. Conversely, HProtoH_2 enhances Eu(III) adsorption onto α,γ-Al_2O_3 in the Eu(III)/HProtoH_2/α,γ-Al_2O_3 ternary system. Adsorption of the acids are also found higher in the Eu(III)/acid/α,γ-Al_2O_3 ternary systems as compared with the corresponding binary systems assessing synergetic effects. For high HPhbH concentrations, a ternary surface species involving ≡AlOH surface sites, Eu(III), and PhbH"– is evidenced by time-resolved luminescence spectroscopy (TRLS). However, in the Eu(III)/HProtoH_2/α,γ-Al_2O_3 ternary system, chemical environment of Eu(III) is found to be very close to that in the Eu(III)/HProtoH_2 binary system. Ternary surface species could not be evidenced in the Eu(III)/HProtoH_2/α,γ-Al_2O_3 ternary system with TRLS because of the very short decay time of Eu(III) in the presence of protocatechuic acid. - Highlights: • Adsorption in the Eu(III) – hydroxybenzoic acid – alumina system is studied. • Adsorption is quantified and luminescence parameters are obtained independently. • Synergistic effect of organic acids adsorption are evidenced in the ternary systems. • A ternary species is clearly shown for the p-hydrobenzoic acid.

  12. Synthesis of Li(x)Na(2-x)Mn2S3 and LiNaMnS2 through redox-induced ion exchange reactions

    International Nuclear Information System (INIS)

    Luthy, Joshua A.; Goodman, Phillip L.; Martin, Benjamin R.

    2009-01-01

    Na 2 Mn 2 S 3 was oxidatively deintercalated using iodine in acetonitrile to yield Na 1.3 Mn 2 S 3 , with lattice constants nearly identical to that of the reactant. Lithium was then reductively intercalated into the oxidized product to yield Li 0.7 Na 1.3 Mn 2 S 3 . When heated, this metastable compound decomposed to form a new crystalline compound, LiNaMnS 2 , along with MnS and residual Na 2 Mn 2 S 3 . Single crystal X-ray diffraction structural analysis of LiNaMnS 2 revealed that this compound crystallizes in P-3m1 with cell parameters a=4.0479(6) A, c=6.7759(14) A, V=96.15(3) A 3 (Z=1, wR2=0.0367) in the NaLiCdS 2 structure-type. - Graphical abstract: Structure of LiNaMnS 2 . Li and Mn are statistically distributed in edge-shared tetrahedral environments linked into infinite planes. Sodium ions occupy interlayer sites

  13. [Effect of acetic acid, furfural and 5-hydroxymethylfurfural on production of 2,3-butanediol by Klebsiella oxytoca].

    Science.gov (United States)

    Wu, Jing; Cheng, Keke; Li, Wenying; Feng, Jie; Zhang, Jian'an

    2013-03-01

    To get the tolerability and consumption of Klebsiella oxytoca on major inhibitors in lignocelluloses hydrolysate, we studied the effect of acetic acid, furfural and 5-hydroxymethylfurfural on production of 2,3-butanediol by Klebsiella oxytoca. The metabolites of furfural and 5-hydroxymethylfurfural were measured. The results show that when acetic acid, furfural and 5-hydroxymethylfurfural was individually added, tolerance threshold for Klebsiella oxytoca was 30 g/L, 4 g/L and 5 g/L, respectively. Acetic acid was likely used as substrate to produce 2,3-butanediol. The yield of 2,3-butanediol increased when acetic acid concentration was lower than 30 g/L. In the fermentation, more than 70% 5-hydroxymethylfurfural was converted to 2,5-furandimethanol. All furfural and the rest of 5-hydroxymethylfurfural were metabolized by Klebsiella oxytoca. It showed that in the detoxification process of 2,3-butanediol production using lignocelluloses hydrolysate, furfural should be given priority to remove and a certain concentration of acetic acid is not need to removal.

  14. Molecular Structure of WlbB, a Bacterial N-Acetyltransferase Involved in the Biosynthesis of 2,3-Diacetamido-2,3-dideoxy-d-mannuronic Acid

    Energy Technology Data Exchange (ETDEWEB)

    Thoden, James B.; Holden, Hazel M. (UW)

    2010-09-08

    The pathogenic bacteria Pseudomonas aeruginosa and Bordetella pertussis contain in their outer membranes the rare sugar 2,3-diacetamido-2,3-dideoxy-D-mannuronic acid. Five enzymes are required for the biosynthesis of this sugar starting from UDP-N-acetylglucosamine. One of these, referred to as WlbB, is an N-acetyltransferase that converts UDP-2-acetamido-3-amino-2,3-dideoxy-D-glucuronic acid (UDP-GlcNAc3NA) to UDP-2,3-diacetamido-2,3-dideoxy-D-glucuronic acid (UDP-GlcNAc3NAcA). Here we report the three-dimensional structure of WlbB from Bordetella petrii. For this analysis, two ternary structures were determined to 1.43 {angstrom} resolution: one in which the protein was complexed with acetyl-CoA and UDP and the second in which the protein contained bound CoA and UDP-GlcNAc3NA. WlbB adopts a trimeric quaternary structure and belongs to the L{beta}H superfamily of N-acyltransferases. Each subunit contains 27 {beta}-strands, 23 of which form the canonical left-handed {beta}-helix. There are only two hydrogen bonds that occur between the protein and the GlcNAc3NA moiety, one between O{sup {delta}1} of Asn 84 and the sugar C-3{prime} amino group and the second between the backbone amide group of Arg 94 and the sugar C-5{prime} carboxylate. The sugar C-3{prime} amino group is ideally positioned in the active site to attack the si face of acetyl-CoA. Given that there are no protein side chains that can function as general bases within the GlcNAc3NA binding pocket, a reaction mechanism is proposed for WlbB whereby the sulfur of CoA ultimately functions as the proton acceptor required for catalysis.

  15. Theoretical insight into the effect of collision energy on the S(3P) + SH( X 2∏) → S2( X 3∑g -) + H(2S) reaction

    Science.gov (United States)

    Shoubao, Gao; Guomeng, Chen; Yuzhi, Song; Qingtian, Meng; Qing, Xu

    2018-01-01

    In this work, the dynamics of reaction S(3P) + SH( X 2∏) → S2( X 3∑g -) + H(2S) has been investigated using quasi-classical trajectories method on a newly constructed accurate double many-body expansion potential energy surface of Song et al. [J. Phys. Chem. A 115, 5274 (2011)]. The integral cross section and the rate constant are obtained. Furthermore, the distribution reflecting vector correlation and the polarization-dependent differential cross section are investigated. The results show a decreasing behavior of the integral cross section as the increasing of the collision energy, and dominate complex forming mechanism at lower energies, as well as the stripping mechanism at higher energies. Those results indicate that the product S2 is sensitively affected by the collision energy.

  16. GPR41/FFAR3 and GPR43/FFAR2 as Cosensors for Short-Chain Fatty Acids in Enteroendocrine Cells vs FFAR3 in Enteric Neurons and FFAR2 in Enteric Leukocytes

    DEFF Research Database (Denmark)

    Nøhr, Mark K; Pedersen, Maria H; Gille, Andreas

    2013-01-01

    The expression of short-chain fatty acid receptors GPR41/FFAR3 and GPR43/ free fatty acid receptor 2 (FFAR2) was studied in the gastrointestinal tract of transgenic monomeric red fluorescent protein (mRFP) reporter mice. In the stomach free fatty acid receptor 3 (FFAR3)-mRFP was expressed...... for the majority of enteroendocrine cells of the small and large intestine and that FFAR3 and FFAR2 both act as sensors for short-chain fatty acids in enteroendocrine cells, whereas FFAR3 apparently has this role alone in enteric neurons and FFAR2 in enteric leukocytes....

  17. Regulation of Auxin Homeostasis and Gradients in Arabidopsis Roots through the Formation of the Indole-3-Acetic Acid Catabolite 2-Oxindole-3-Acetic Acid

    Czech Academy of Sciences Publication Activity Database

    Pěnčík, A.; Simonovik, B.; Petersson, S.V.; Hényková, Eva; Simon, Sibu; Greenham, K.; Zhang, Y.; Kowalczyk, M.; Estelle, M.; Zažímalová, Eva; Novák, Ondřej; Sandberg, G.; Ljung, K.

    2013-01-01

    Roč. 25, č. 10 (2013), s. 3858-3870 ISSN 1040-4651 R&D Projects: GA ČR(CZ) GAP305/11/0797 Institutional research plan: CEZ:AV0Z50380511 Keywords : BOX PROTEIN TIR1 * PLANT DEVELOPMENT * OXINDOLE-3-ACETIC ACID Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 9.575, year: 2013

  18. [Synthesis and biological activity of 2,3-secotriterpene acid mono- and diamides].

    Science.gov (United States)

    Tolmacheva, I A; Igosheva, E V; Vikharev, Iu B; Grishko, V V; Savinova, O V; Boreko, E I; Eremin, V F

    2013-01-01

    Four types of amide (C3; C28; C3-C28) conjugates based on 2,3-seco-18alphaH-oleanane and 2,3-secolupane mono- and dicarboxylic acids were synthesized. The range of diamide derivatives was supplemented with C3-C3' and C28-C28' dicondensed amides with two A-secotriterpene backbones educed by reacting monocarboxylic A-secoacids with biogenic amino acid lysine. Compounds with inhibitory action against herpes virus reproduction (EC50 8.7 and 4.1 McM) were found among the synthesized mono- and diamide derivatives containing an ethyl-beta-alaninate fragment. It has been ascertained that diamide with ethyl-beta-alaninate fragment combines anti-herpes virus properties and anti-HIV activity (EC50 5.1 McM). For active compounds, the maximum non-toxic concentration (MNTC)/EC50 ratios ranges from 9.7 to 40.8. The synthesized amide conjugates do not exhibit any marked cytotoxic effects against human tumor cell lines rabdomiosarcoma RD TE32, A549 lung carcinoma and melanoma MS.

  19. Deoxygenation of palm kernel oil to jet fuel-like hydrocarbons using Ni-MoS_2/γ-Al_2O_3 catalysts

    International Nuclear Information System (INIS)

    Itthibenchapong, Vorranutch; Srifa, Atthapon; Kaewmeesri, Rungnapa; Kidkhunthod, Pinit; Faungnawakij, Kajornsak

    2017-01-01

    Highlights: • The Ni-MoS_2/γ-Al_2O_3 catalysts synthesized using thiourea solution processing. • The Ni-MoS_2 showed semi-amorphous crystallinity with crystallite size of 5–10 nm. • The Ni K-edge XANES and EXAFS indicated the Ni substitution in MoS_2 structure. • A high yield of jet fuel-like hydrocarbon (>90%) from the palm kernel oil feedstock. • The HDO pathway was highly selective, while the DCO_2 and DCO pathways were minor. - Abstract: In the current study, palm kernel oil was used as a renewable feedstock for production of jet fuel-like hydrocarbons via the deoxygenation over the Ni-MoS_2/γ-Al_2O_3 catalyst. The dominant C12 fatty acid content in palm kernel oil makes it promising for jet fuel application. Synthesized by a liquid processing method with thiourea organosulfur agent, the catalyst revealed MoS_2 structure with low stacking, while Ni substitution in the MoS_2 structure and interaction with the Al_2O_3 support were determined based on the Ni K-edge XANES and EXAFS results. A high hydrodeoxygenation (HDO) activity, which as the major pathway in the deoxygenation, was observed upon application of a H_2 pressure of 30–50 bar over Ni-MoS_2/γ-Al_2O_3. The optimum product yield of approximately 92% was obtained mainly from the HDO pathway (∼60%) with 58% selectivity to C10–C12 jet fuel hydrocarbons. The flow property of the jet fuel-like hydrocarbons was more desirable than those obtained from palm olein oil-derived fuel.

  20. (1S,3S,4S-tert-Butyl N-[1-benzyl-3-hydroxy-5-phenyl-4-(picolinamidopentyl]carbamate

    Directory of Open Access Journals (Sweden)

    Jian-Feng Zheng

    2008-07-01

    Full Text Available The title compound, C29H35N3O4, was obtained by the reaction of (2S,4S,5S-tert-butyl N-(4-amino-1-benzyl-3-hydroxy-5-phenylpentylcarbamate and picolinic acid using oxalyl chloride as a chlorinating reagent to activate the carboxyl group. In the crystal structure there are two molecules in the asymmetric unit, which are aligned edge-to-face. In one molecule, the pyridyl ring forms a dihedral angle of 22.0 (1° with the phenyl ring of the terminal benzyl group and 14.3 (1° with the other phenyl ring; in the other molecule, the corresponding angles are 12.1 (1 and 10.6 (1°, respectively. The packing is stabilized by intermolecular hydrogen bonds and C—H...π interactions.

  1. Deracemization of Racemic Amino Acids Using (R)- and (S)-Alanine Racemase Chiral Analogues as Chiral Converters

    International Nuclear Information System (INIS)

    Paik, Manjeong; Jeon, So Hee; Lee, Wonjae; Kang, Jong Seong; Kim, Kwan Mook

    2014-01-01

    Our findings show that both (R)- and (S)-ARCA can be practical chiral converters for L- and D-amino acids, respectively, in the deracemization of racemic amino acids. The overall stereoselectivities of both chiral converters are generally greater than 90%. In addition, we developed chiral and achiral HPLC methods for the analysis of stereoselectivity determination. This chromatographic method proved much more accurate and convenient at determining both enantiomer and diastereomer purity than did those previously reported. Deracemization is the stereoselective process of converting a racemate into either a pure enantiomer or a mixture in which one enantiomer is present in excess.1 Previous studies have shown that (S)-alanine racemase chiral analogue (ARCA) [(S)-2-hydroxy-2'-(3-phenyluryl-benzyl)-1,1'-binaphthyl-3-carboxaldehyde], developed as a chiral convertor compound that imitates the function of alanine racemase, plays an essential role in the stereoselective conversion of amino acid. Since (S)-ARCA showed a higher stability with D-amino acids than with L-amino acids, several L-amino acids were preferentially converted to D-amino acids via (S)-ARCA/D-amino acid imine diastereomer formation. For the deracemization process undertaken in this study, we utilized both (R)-ARCA and (S)-ARCA as chiral converters, which were expected to generate L- and D-amino acids, respectively, from the starting racemic mixtures

  2. Reaction kinetics of nitrous acid with acetohydroxamic acid in HClO4 and HNO3 medium

    International Nuclear Information System (INIS)

    Zheng Weifang; Yan Taihong; Bian Xiaoyan; Zhang Yu

    2007-01-01

    The presence of nitrous acid in feed solution of PUREX process is unavoidable. Owing to its effect on the valence of plutonium and other nuclides, nitrous acid should be scavenged. The kinetics of reaction of AHA with nitrous acid was studied in HClO 4 and HNO 3 medium. The reaction rate equation in HClO 4 and HNO 3 medium is obtained as. --dc(HNO 2 )/dr= k·c(HNO 2 ) 1 ·c(AHA) 0.75 ·c(HClO 4 ) 0.5 and --dc(HNO 2 )/dt=k·c(HNO 2 ) 1 ·c(AHA) 0.25 .· c(HNO 3 ) 1 , respectively. In HClO 4 medium, the reaction rate constant (k) is found to be (2.37±0.21) L 1.25 /(mol 1.25 ·s) at θ=5 degree C, I=0.5 mol/kg. Reaction rate constant is increased slightly with the increased ion strength in the range of 0.5-2.0 mol/kg. In HNO 3 medium, the reaction rate constant (k) is found to be (0.482±0.048) L 1.25 /(mol 1.25 ·s) at θ=10 degree C and I= 0.5 mol/kg. Reaction rate constant is also increased slightly with the increased ion strength in the range of 0.5-3.0 mol/kg. The effect of temperature to the reaction rate is also studied. The results show that with the increase of temperature, the reaction rate increases quickly. And the activation energy is found to be 99.0 kJ/mol and 46.9 kJ/mol respectively in HNO 3 . (authors)

  3. Deuterium incorporation experiments from (3R)- and (3S)-[3-2H]leucine into characteristic isoprenoidal lipid-core of halophilic archaea suggests the involvement of isovaleryl-CoA dehydrogenase.

    Science.gov (United States)

    Yamauchi, Noriaki; Tanoue, Ryo

    2017-11-01

    The stereochemical reaction course for the two C-3 hydrogens of leucine to produce a characteristic isoprenoidal lipid in halophilic archaea was observed using incubation experiments with whole cell Halobacterium salinarum. Deuterium-labeled (3R)- and (3S)-[3- 2 H]leucine were freshly prepared as substrates from 2,3-epoxy-4-methyl-1-pentanol. Incorporation of deuterium from (3S)-[3- 2 H]leucine and loss of deuterium from (3R)-[3- 2 H]leucine in the lipid-core of H. salinarum was observed. Taken together with the results of our previous report, involving the incubation of chiral-labeled [5- 2 H]leucine, these results strongly suggested an involvement of isovaleryl-CoA dehydrogenase in leucine conversion to isoprenoid lipid in halophilic archaea. The stereochemical course of the reaction (anti-elimination) might have been the same as that previously reported for mammalian enzyme reactions. Thus, these results suggested that branched amino acids were metabolized to mevalonate in archaea in a manner similar to other organisms.

  4. Safety demonstration test (SR-3/S1C-3/S2C-3/SF-2) plan using the HTTR. Contract research

    International Nuclear Information System (INIS)

    Nakagawa, Shigeaki; Sakaba, Nariaki; Takamatsu, Kuniyoshi; Takada, Eiji; Tochio, Daisuke; Ohwada, Hiroyuki

    2005-03-01

    Safety demonstration tests using the HTTR are to be conducted from the FY2002 to verify the inherent safety features and to improve the safety design and evaluation technologies for HTGRs, as well as to contribute to not only the commercial HTGRs but also the research and development for the VHTR that is one of the Generation IV reactor candidates. This paper describes the reactivity insertion test (SR-3), the coolant flow reduction test by tripping of gas circulators (S1C-3, S2C-3), and the partial flow loss of coolant test (SF-2) planned in March 2005 with their detailed test method, procedure and results of pre-test analysis. From the analytical results, it was verified that the negative reactivity feedback effect of the core brings the reactor power safely to a stable level without a reactor scram. (author)

  5. Sb{sub 2}S{sub 3}:C/CdS p-n junction by laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Arato, A. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon (Mexico); Centro de Innovacion, Investigacion y Desarrollo en Ingenieria y Tecnologia-Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico); Cardenas, E. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon (Mexico); Shaji, S. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon (Mexico); Centro de Innovacion, Investigacion y Desarrollo en Ingenieria y Tecnologia-Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico); O' Brien, J.J.; Liu, J. [Center for Nanoscience, University of Missouri-St. Louis, One University Boulevard, St. Louis, Missouri-63121 (United States); Department of Chemistry and Biochemistry, University of Missouri-St. Louis, One University Boulevard, St. Louis, Missouri-63121 (United States); Castillo, G. Alan; Das Roy, T.K. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon (Mexico); Krishnan, B. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon (Mexico); Centro de Innovacion, Investigacion y Desarrollo en Ingenieria y Tecnologia-Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico)], E-mail: bkrishnan@fime.uanl.mx

    2009-02-02

    In this paper, we report laser irradiated carbon doping of Sb{sub 2}S{sub 3} thin films and formation of a p-n junction photovoltaic structure using these films. A very thin carbon layer was evaporated on to chemical bath deposited Sb{sub 2}S{sub 3} thin films of approximately 0.5 {mu}m in thickness. Sb{sub 2}S{sub 3} thin films were prepared from a solution containing SbCl{sub 3} and Na{sub 2}S{sub 2}O{sub 3} at 27 deg. C for 5 h and the films obtained were highly resistive. These C/Sb{sub 2}S{sub 3} thin films were irradiated by an expanded laser beam of diameter approximately 0.5 cm (5 W power, 532 nm Verdi laser), for 2 min at ambient atmosphere. Morphology and composition of these films were analyzed. These films showed p-type conductivity due to carbon diffusion (Sb{sub 2} S{sub 3}:C) by the thermal energy generated by the absorption of laser radiation. In addition, these thin films were incorporated in a photovoltaic structure Ag/Sb{sub 2}S{sub 3}:C/CdS/ITO/Glass. For this, CdS thin film of 50 nm in thickness was deposited on a commercially available ITO coated glass substrate from a chemical bath containing CdCl{sub 2}, sodium citrate, NH{sub 4}OH and thiourea at 70 deg. C . On the CdS film, Sb{sub 2}S{sub 3}/C layers were deposited. This multilayer structure was subjected to the laser irradiation, C/Sb{sub 2}S{sub 3} side facing the beam. The p-n junction formed by p-Sb{sub 2}S{sub 3}:C and n-type CdS showed V{sub oc} = 500 mV and J{sub sc} = 0.5 mA/cm{sup 2} under illumination by a tungsten halogen lamp. This work opens up a new method to produce solar cell structures by laser assisted material processing.

  6. Total synthesis of leopolic acid A, a natural 2,3-pyrrolidinedione with antimicrobial activity

    Directory of Open Access Journals (Sweden)

    Atul A. Dhavan

    2016-07-01

    Full Text Available The first total synthesis of leopolic acid A, a fungal metabolite with a rare 2,3-pyrrolidinedione nucleus linked to an ureido dipeptide, was designed and carried out. Crucial steps for the strategy include a Dieckmann cyclization to obtain the 2,3-pyrrolidinedione ring and a Wittig olefination to install the polymethylene chain. An oxazolidinone-containing leopolic acid A analogue was also synthesized. The antibacterial activity showed by both compounds suggests that they could be considered as promising candidates for future developments.

  7. Laser spectroscopy of the 4s4p(3) P-2-4s3d(1) D-2 transition on magnetically trapped calcium atoms

    NARCIS (Netherlands)

    Dammalapati, U.; Norris, I.; Burrows, C.; Riis, E.

    2011-01-01

    Laser excitation of the 4s4p(3) P-2-4s3d(1) D-2 transition in atomic calcium has been observed and the wavelength determined to 1530.5298(6) nm. The metastable 4s4p(3) P-2 atoms were magnetically trapped in the quadrupole magnetic field of a magneto-optical trap. This state represents the only

  8. Antiviral activity of 3(2H- and 6-chloro-3(2H-isoflavenes against highly diverged, neurovirulent vaccine-derived, type2 poliovirus sewage isolates.

    Directory of Open Access Journals (Sweden)

    Lester M Shulman

    Full Text Available BACKGROUND: Substituted flavanoids interfere with uncoating of Enteroviruses including Sabin-2 polio vaccine strains. However flavanoid resistant and dependent, type-2 polio vaccine strains (minimally-diverged, emerged during in vitro infections. Between 1998-2009, highly-diverged (8 to >15% type-2, aVDPV(2s, from two unrelated persistent infections were periodically isolated from Israeli sewage. AIM: To determine whether highly evolved aVDPV(2s derived from persistent infections retained sensitivity to isoflavenes. METHODS: Sabin-2 and ten aVDPV(2 isolates from two independent Israeli sources were titered on HEp2C cells in the presence and absence of 3(2H- Isoflavene and 6-chloro-3(2H-Isoflavene. Neurovirulence of nine aVDPV(2s was measured in PVR-Tg-21 transgenic mice. Differences were related to unique amino acid substitutions within capsid proteins. PRINCIPAL FINDINGS: The presence of either flavanoid inhibited viral titers of Sabin-2 and nine of ten aVDPV(2s by one to two log(10. The tenth aVDPV(2, which had unique amino acid substitution distant from the isoflavene-binding pocket but clustered at the three- and five-fold axies of symmetry between capsomeres, was unaffected by both flavanoids. Genotypic neurovirulence attenuation sites in the 5'UTR and VP1 reverted in all aVDPV(2s and all reacquired a full neurovirulent phenotype except one with amino acid substitutions flanking the VP1 site. CONCLUSION: Both isoflavenes worked equally well against Sabin 2 and most of the highly-diverged, Israeli, aVDPV(2s isolates. Thus, functionality of the hydrophobic pocket may be unaffected by selective pressures exerted during persistent poliovirus infections. Amino acid substitutions at sites remote from the drug-binding pocket and adjacent to a neurovirulence attenuation site may influence flavanoid antiviral activity, and neurovirulence, respectively.

  9. Calorimetric determination of enthalpy changes for the proton ionization of 3-[N-morpholino]propanesulfonic acid (MOPS), 4-[N-morpholino]butanesulfonic acid (MOBS) and 3-[N-morpholino]-2-hydroxypropanesulfonic acid (MOPSO) in water-methanol mixtures

    International Nuclear Information System (INIS)

    Jumean, F.H.; Abdo, N.M.; Khamis, M.I.

    2011-01-01

    Highlights: → Two-stage proton ionizations for three N-substituted sulfonic acid derivatives of morpholine. → ΔH 1 and ΔH 2 in x methanol = 0-0.360 measured for MOPS, MOBS and MOPSO. → In water, ΔH 1 = ±1.2 kJ mol -1 , ΔH 2 range 20.7-26.3 kJ mol -1 . → Methanol addition had little effect on ΔH 1 but ΔH 2 rose steadily to 32.2 kJ mol -1 . → Results related to molecular and solvent parameters. - Abstract: Proton ionization enthalpies for three structurally related biological buffers, each with two ionizable protons, were determined using solution calorimetry. These buffers are 3-[N-morpholino]propanesulfonic acid (MOPS), 4-[N-morpholino]butanesulfonic acid (MOBS) and 3-[N-morpholino]-2-hydroxypropanesulfonic acid (MOPSO). Enthalpies were obtained in water-methanol mixtures with methanol mole fraction (X m ) from 0 to 0.360. The first ionization enthalpy (ΔH 1 ) of all buffers was small (±1.2 kJ mol -1 ) at all solvent compositions. The second ionization enthalpy (ΔH 2 ) increased steadily with X m , rising from 20.7 to 25.6 kJ mol -1 for MOPS, 26.3-31.0 kJ mol -1 for MOBS and 23.5-32.2 kJ mol -1 for MOPSO. The results were compared to those for related biological buffers. The observed variations were interpreted in terms of solvent-solvent and solvent-solute interactions.

  10. Role of leucine in isoprenoid metabolism. Incorporation of (3-/sup 13/C)leucine and of (2-/sup 3/H,4-/sup 14/C)-. beta. ,. beta. -dimethyl-acrylic acid into phytosterols by tissue cultures of Andrographis paniculata

    Energy Technology Data Exchange (ETDEWEB)

    Anastasis, P; Freer, I; Overton, K; Rycroft, D; Singh, S B [Glasgow Univ. (UK). Dept. of Chemistry

    1985-02-01

    (3-/sup 13/C)Leucine is incorporated into phytosterols by tissue cultures of Andrographis paniculata by breakdown to acetyl-CoA and its subsequent incorporation via (3S)-3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) and mevalonic acid; (2-/sup 3/H,4-/sup 14/C)-..beta..,..beta..-dimethylacrylic acid also is not incorporated intact.

  11. Folic acid: a marker of endothelial function in type 2 diabetes?

    Directory of Open Access Journals (Sweden)

    Arduino A Mangoni

    2005-04-01

    Full Text Available Arduino A Mangoni1, Roy A Sherwood2, Belinda Asonganyi2, Emma L Ouldred3, Stephen Thomas4, Stephen HD Jackson31Department of Clinical Pharmacology, Centre for Neuroscience, School of Medicine, Flinders University, Adelaide, SA, Australia; 2Clinical Biochemistry, King’s College Hospital, London, UK; 3Department of Health Care of the Elderly, Guy’s, King’s, and St Thomas’ School of Medicine, King’s College, London, UK; 4Department of Diabetic Medicine, King’s College Hospital, London, UKObjectives: Endothelial dysfunction is a common feature of type 2 diabetes. Recent studies suggest that the B-vitamin folic acid exerts direct beneficial effects on endothelial function, beyond the well known homocysteine lowering effects. Therefore, folic acid might represent a novel “biomarker” of endothelial function. We sought to determine whether plasma levels of folic acid determine endothelial-dependent vasodilation in patients with type 2 diabetes.Methods: Forearm arterial blood flow (FABF was measured at baseline and during intrabrachial infusion of the endothelial-dependent vasodilator acetylcholine (15 µg/min and the endothelial-independent vasodilator sodium nitroprusside (2 µg/min in 26 type 2 diabetic patients (age 56.5 ± 0.9 years, means ± SEM with no history of cardiovascular disease.Results: FABF ratio (ie, the ratio between the infused and control forearm FABF significantly increased during acetylcholine (1.10 ± 0.04 vs 1.52 ± 0.07, p < 0.001 and sodium nitroprusside (1.12 ± 0.11 vs 1.62 ± 0.06, p < 0.001 infusions. After correcting for age, gender, diabetes duration, smoking, hypertension, body mass index, microalbuminuria, glycated hemoglobin, low-density lipoprotein cholesterol, and homocysteine, multiple regression analysis showed that plasma folic acid concentration was the only independent determinant (p = 0.037, R2 = 0.22 of acetylcholine-mediated, but not sodium nitroprusside-mediated, vasodilatation

  12. Metabolism of 7-14C-2,3,5 triodobenzoic acid (TIBA) in soybeans plant (Glycine max)

    International Nuclear Information System (INIS)

    Sant'Anna, R.; Ohlrogge, A.J.; Christian, J.E.

    1975-01-01

    A metabolic study was done in mature seeds of field grown soybeans sprayed with 7- 14 C-2,3,5 triiodobenzoic acid (TIBA) at the onset of flowering. Seed extraction with 95% alcohol yielded only 65% of the total radioactivity present. No further studies were performed on the ethanol insoluble fraction. Upon acid base purification of the 14 C seed extracts, the ether phase (pH 9,0) contained about 70% of the activity suggesting the existence of a low polarity compound(s). Acid hydrolysis of the alcoholic extracts increased the radioactivity in the ether soluble fraction, while the basic treatment decreased it about the same level as for free TIBA. The latter behaviour seemed to indicate hydrolysis of a conjugation product(s). Alumina column chromatography was unsuccessful for separating the oil-activity combination; however, three radioactive peaks were obtained. The first two peaks degrated to form the last one, which coincided with the TIBA peak. When the alcoholic extracts were run in a Sephadex LH-20 column, oils, proteins and pigments separated from the radioactivity. Two main peaks appeared for the 14 C seeds extracts. Peak I was essentially unaltered when it was co-cromatographed with the standard 14 C-TIBA, peak II was indistinguishable from the TIBA peak. Although the work did not reach the final stage of caracterization, postulation was made for a conjugate nature of the ester type for peak I and the correspondence of peak II with free TIBA or TIBA in mixture with related compounds, such as 2,5 DIBA and 3,5 DIBA, products of its deiodination [pt

  13. 2-{[4-(1,3-Benzothiazol-2-ylphenyl](methylamino}acetic acid

    Directory of Open Access Journals (Sweden)

    Yong Zhang

    2009-11-01

    Full Text Available In the title compound, C16H14N2O2S, the dihedral angle between the benzothiazole ring system and benzene ring is 3.11 (2°. In the crystal structure, intermolecular O—H...N hydrogen bonds link molecules into chains along [100] and these chains are, in turn, linked into a three-dimensional network via weak intermolecular C—H...O hydrogen bonds.

  14. (S-Methyl 2-benzamido-3-(3,4-dimethoxyphenylpropanoate

    Directory of Open Access Journals (Sweden)

    Tricia Naicker

    2012-01-01

    Full Text Available The dimethoxypbenzene ring in the title compound, C19H21NO5, is gauche to the amide group and anti to the ester group. The chirality was confirmed to be S from two-dimensional NMR spectroscopy. In the crystal, N—H...O and C—H...O hydrogen bonds and several short-contact interactions (2.07–3.45 Å create chains parallel to [110]. The phenyl ring is disordered over two orientations in a 0.54 (2:0.46 (2 ratio.

  15. Preparation and characterization Al3+-bentonite Turen Malang for esterification fatty acid (palmitic acid, oleic acid and linoleic acid)

    Science.gov (United States)

    Abdulloh, Abdulloh; Aminah, Nanik Siti; Triyono, Mudasir, Trisunaryanti, Wega

    2016-03-01

    Catalyst preparation and characterization of Al3+-bentonite for esterification of palmitic acid, oleic acid and linoleic acid has been done. Al3+-bentonite catalyst was prepared from natural bentonite of Turen Malang through cation exchange reaction using AlCl3 solution. The catalysts obtained were characterized by XRD, XRF, pyridine-FTIR and surface area analyser using the BET method. Catalyst activity test of Al3+-bentonite for esterification reaction was done at 65°C using molar ratio of metanol-fatty acid of 30:1 and 0.25 g of Al3+-bentonite catalyst for the period of ½, 1, 2, 3, 4 and 5 hours. Based on the characterization results, the Al3+-bentonite Turen Malang catalyst has a d-spacing of 15.63 Ǻ, acid sites of Brönsted and Lewis respectively of 230.79 µmol/g and 99.39 µmol/g, surface area of 507.3 m2/g and the average of radius pore of 20.09 Å. GC-MS analysis results of the oil phase after esterification reaction showed the formation of biodiesel (FAME: Fatty acid methyl ester), namely methyl palmitate, methyl oleate and methyl linoleate. The number of conversions resulted in esterification reaction using Al3+-bentonite Turen Malang catalyst was 74.61%, 37.75%, and 20, 93% for the esterification of palmitic acid, oleic acid and linoleic acid respectively.

  16. Spectral characteristics of 2-(4'-amino-3-pyridyl)benzimidazole: Effects of solvent and acid or base concentration

    International Nuclear Information System (INIS)

    Dogra, Sneh K.

    2006-01-01

    Spectral characteristics of 2-(4'-amino-3-pyridyl)benzimidazole (4-A3PyBI) have been studied in different solvents, as well as at different acid or base concentrations using absorption, fluorescence excitation and fluorescence spectroscopy. Excited singlet state (S 1 ) lifetimes for each species were measured using nanosecond time-dependent spectrofluorimeter. AM1 semi-empirical and density functional theoretical (DFT) calculations were performed on each species for the spectral assignment. From the above results it is concluded that 4-A3PyBI exists only in the amine form. First protonation occurs at pyridine=N- atom and second protonation at the benzimidazole (BI)=N- atom. When dication (DC) species is excited, two emission bands are observed, having the same fluorescence excitation spectra, suggesting the same ground state (S ) precursor. Short wavelength (SW) emission band is assigned to the π-π* transition and long wavelength (LW) emission to the charge transfer transition. First deprotonation in S state occurs from >N-H moiety, whereas in S 1 state it is from -NH 2 group. Monoanion (MA) so formed in S 1 state is non-fluorescent. Dianion (DA) is formed by further deprotonating >N-H moiety in S 1 state and it is fluorescent. pK a values were determined and discussed

  17. Interaction of La3+, Ce3+, Pr3+ and Sm3+ with DL-aspartic acid in dimethyl sulphoxide

    International Nuclear Information System (INIS)

    Saxena, M.C.; Saxena, R.S.

    1980-01-01

    La(III), Ce(III), Pr(III) and Sm(III) form 1:1 and 1:2 complexes with DL-aspartic acid in 20% aq. dimethyl sulphoxide at μ = 0.1M (NaClO 4 ) as revealed by pH-metric and conductometric titrations. Stabilities of the complexes follow the order: La 3+ 3+ 3+ 3+ . The overall changes in ΔG, ΔH and ΔS for the metal-ligand interaction have also been reported at 30deg C. (auth.)

  18. One step hydrothermal synthesis of 3D CoS2@MoS2-NG for high performance supercapacitors.

    Science.gov (United States)

    Meng, Qi; Chen, Yizhi; Zhu, Wenkun; Zhang, Ling; Yang, Xiaoyong; Duan, Tao

    2018-05-03

    A three-dimensional (3D) MoS 2 coated CoS 2 -nitrogen doped graphene (NG) (CoS 2 @MoS 2 -NG) hybrid has been synthesized by a one step hydrothermal method as supercapacitor (SC) electrode material for the first time. Such a composite consists of NG embedded with stacked CoS 2 @MoS 2 sheets. With a 3D skeleton, it prevents the agglomeration of CoS 2 @MoS 2 nanoparticles, resulting in sound conductivity, rich porous structures and a large surface area. The results indicate that CoS 2 @MoS 2 -NG has higher specific capacitance (198 F g -1 at 1 A g -1 ), better rate performance (with about 56.57% from 1 to 16 A g -1 ) and an improved cycle stability (with about 96.97% after 1000 cycles). It is an ideal candidate for SC electrode materials.

  19. Synthesis of (R,S)-[2,3-{sup 13}C{sub 2}]-1-(1`-methyl-2`-pyrrolidinyl)propan-2-one; {l_brace}(R,S)-[2`,3`-{sup 13}C{sub 2}]hygrinePound right bracePound

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, T.W.; Leete, Edward [Minnesota Univ., Minneapolis, MN (United States). Dept. of Chemistry

    1996-05-01

    2-Ethoxy-1-methyl-5-pyrrolidinone (1) was reacted with ethyl [3,4-{sup 13}C{sub 2}]-acetoacetate (2) in the presence of TiCl{sub 4} to give ethyl [3,4-{sup 13}C{sub 2}]-2-(1`-methyl-5`-oxo-2`-pyrrolidinyl)-3-oxobutanoate (3) in 85% yield. Decarboethoxylation of ethyl [3,4-{sup 13}C{sub 2}]-2-(1`-methyl-5`-oxo-2`-pyrrolidinyl)-3-oxobutan-oate (3) was accomplished using NaCl and H{sub 2}O in DMSO to give (R,S)-[2,3-{sup 13}C{sub 2}]-1-(1`-methyl-5`-oxo-2`-pyrrolidinyl)propan-2-o ne (4) in 91% yield. Protection of the ketone as a ketal (ethylene glycol, H{sup +}), followed by reduction of the amide to the amine using LiAlH{sub 4} and subsequent deprotection of the ketal gave (R,S)-[2,3-{sup 13}C{sub 2}]-1-(1`-methyl-2`-pyrrolidinyl)propan-2-one ((R,s)-[2`, 3`-{sup 13}C{sub 2}]Hygrine) (8) in 78% yield. (61% overall yield from ethyl [3,4-{sup 13}C{sub 2}]acetoacetate). (Author).

  20. Synthesis, physical and chemical properties of 2-((4-(R-amino-5-(thiophen-2-ylmethyl-4H-1,2,4-triazol-3-ylthioacetic acids salts

    Directory of Open Access Journals (Sweden)

    А.А. Safonov

    2017-12-01

    Full Text Available Thanks to the rapid development of science, humanity has achieved remarkable success in various fields. This also applies to the synthesis of biological compounds. Over the centuries, scientists have invented many methods and drugs that are being actively used to date. Derivatives of 1,2,4-triazole can be the foundation for the manufacture of new native drugs that will compete with foreign ones. The aim of work was synthesis and confirmation the structure of 2-((4-(R-amino-5-(thiophen-2-ylmethyl-4H-1,2,4-triazol-3-ylthioacetate acids salts. Materials and methods. As starting substances we used 2-((4-(R-amino-5-(thiophen-2-ylmethyl-4H-1,2,4-triazol-3-ylthioacetic acids, which were synthesized by previously described methods. The structure of synthesized compounds was confirmed by the complex use of modern physical-chemical methods of analysis: elemental analysis, 1H-NMR spectroscopy, HPLC-MS. Results. Salts of 2-((4-(R-amino-5-(thiophen-2-ylmethyl-4H-1,2,4-triazol-3-ylthioacetic acids were synthesized by the interaction of the appropriate acids with organic (morpholin, methanamin, 2-hydroxyethanamin, inorganic basics (aqueous ammonia solution, sodium hydroxide and salts (zinc sulfate, ferrum (III chloride, magnesium sulfate, copper (II sulfate in alcoholic or aqueous media. Conclusions. A series of novel 2-((4-(R-amino-5-(thiophen-2-ylmethyl-4H-1,2,4-triazol-3-ylthioacetic acids salts were synthesized. The structure of synthesized compounds is established using modern physical-chemical methods of analysis.

  1. Anticonvulsant and neuroprotective effect of (S)-3,4-dicarboxyphenylglycine against seizures induced in immature rats by homocysteic acid

    Czech Academy of Sciences Publication Activity Database

    Folbergrová, Jaroslava; Druga, Rastislav; Haugvicová, Renata; Mareš, Pavel; Otáhal, Jakub

    2008-01-01

    Roč. 54, č. 4 (2008), s. 665-675 ISSN 0028-3908 R&D Projects: GA ČR GA309/02/1238; GA ČR(CZ) GA309/05/2015 Institutional research plan: CEZ:AV0Z50110509 Keywords : DL-homocysteic acid induced seizures * mGluR8 agonist (S)-3,4-DCPG * protection Subject RIV: FH - Neurology Impact factor: 3.383, year: 2008

  2. Synthesis and Biological Activity of 3-[Phenyl(1,3-thiazol-2-yl-amino]propanoic Acids and Their Derivatives

    Directory of Open Access Journals (Sweden)

    Vytautas Mickevičius

    2013-12-01

    Full Text Available New N,N-disubstituted β-amino acids and their derivatives with thiazole, aromatic, and heterocyclic substituents were synthesized from N-phenyl-N-thiocarbamoyl-β-alanine by the Hantzsch method; derivatives with hydrazone fragments were also obtained. Some of the synthesized compounds exhibited discrete antimicrobial activity, and 3-[(4-oxo-4,5-dihydro-1,3-thiazol-2-yl(phenylamino]propanoic acid was found to promote rapeseed growth and to increase seed yield and oil content.

  3. Acid phosphomonoesterase (E.C. 3.1.3.2) location in soil

    Czech Academy of Sciences Publication Activity Database

    Rejšek, K.; Vránová, V.; Pavelka, Marian; Formánek, P.

    2012-01-01

    Roč. 175, č. 5 (2012), s. 196-211 ISSN 1436-8730 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073; GA MŠk(CZ) LM2010007 Institutional research plan: CEZ:AV0Z60870520 Keywords : acid phosphomonoesterase * soil * roots * mycorrhizal fungi * location * extraction Subject RIV: EH - Ecology, Behaviour Impact factor: 1.380, year: 2012

  4. The oxanorbornene approach to 3-hydroxy, 3,4-dihydroxy and 3,4,5-trihydroxy derivatives of 2-aminocyclohexanecarboxylic acid

    Directory of Open Access Journals (Sweden)

    Howard Judith AK

    2006-05-01

    Full Text Available Abstract The nitro oxanorbornene adduct derived from the Diels-Alder reaction of ethyl (E-3-nitroacrylate and furan provides a versatile template for the stereoselective synthesis of hydroxylated derivatives of 2-aminocyclohexanecarboxylic acid (ACHC.

  5. Introducing ionic and/or hydrogen bonds into the SAM//Ga2O3 top-interface of Ag(TS)/S(CH2)nT//Ga2O3/EGaIn junctions.

    Science.gov (United States)

    Bowers, Carleen M; Liao, Kung-Ching; Yoon, Hyo Jae; Rappoport, Dmitrij; Baghbanzadeh, Mostafa; Simeone, Felice C; Whitesides, George M

    2014-06-11

    Junctions with the structure Ag(TS)/S(CH2)nT//Ga2O3/EGaIn (where S(CH2)nT is a self-assembled monolayer, SAM, of n-alkanethiolate bearing a terminal functional group T) make it possible to examine the response of rates of charge transport by tunneling to changes in the strength of the interaction between T and Ga2O3. Introducing a series of Lewis acidic/basic functional groups (T = -OH, -SH, -CO2H, -CONH2, and -PO3H) at the terminus of the SAM gave values for the tunneling current density, J(V) in A/cm(2), that were indistinguishable (i.e., differed by less than a factor of 3) from the values observed with n-alkanethiolates of equivalent length. The insensitivity of the rate of tunneling to changes in the terminal functional group implies that replacing weak van der Waals contact interactions with stronger hydrogen- or ionic bonds at the T//Ga2O3 interface does not change the shape (i.e., the height or width) of the tunneling barrier enough to affect rates of charge transport. A comparison of the injection current, J0, for T = -CO2H, and T = -CH2CH3--two groups having similar extended lengths (in Å, or in numbers of non-hydrogen atoms)--suggests that both groups make indistinguishable contributions to the height of the tunneling barrier.

  6. Indirect approach to C-3 branched 1,2-cis-glycofuranosides: synthesis of aceric acid glycoside analogues.

    Science.gov (United States)

    de Oliveira, Marcelo T; Hughes, David L; Nepogodiev, Sergey A; Field, Robert A

    2008-02-04

    Aceric acid (3-C-carboxy-5-deoxy-alpha-l-xylofuranose) residues are present in pectic polysaccharide rhamnogalacturonan II (RG II) in the form of synthetically challenging 1,2-cis-glycofuranosides. To access synthetic fragments of RG II incorporating aceric acid, a four-step procedure based on C-2 epimerisation of initially prepared 1,2-trans-glycofuranoside was developed. Readily available derivatives of branched-chain l-lyxofuranose bearing a 3-C-vinyl group as a masked 3-C-carboxyl group were investigated as potential precursors of aceric acid units. In the first step of the procedure, installation of a participating group at C-2 of the furanose ring ensured stereocontrol of the O-glycosylation, which was carried out with the thioglycoside of 2-O-acetyl-3,5-di-O-benzyl-3-C-vinyl-L-lyxofuranose. After the glycosylation step, the 2-O-acetyl group was removed, the free 2-OH group was oxidised and the resulting ketone was finally reduced to form the C-3-vinyl-L-xylofuranoside. The use of L-Selectride in the key reduction reaction was essential to achieve the required stereoselectivity to generate 1,2-cis-furanoside.

  7. Convenient enzymatic resolution of (R,S)-2-methylbutyric acid catalyzed by immobilized lipases.

    Science.gov (United States)

    Mittersteiner, Mateus; Linshalm, Bruna Luiza; Vieira, Ana Paula Furlan; Brondani, Patrícia Bulegon; Scharf, Dilamara Riva; de Jesus, Paulo Cesar

    2018-01-01

    The application of several immobilized lipases has been explored in the enantioselective esterification of (R,S)-2-methylbutyric acid, an insect pheromone precursor. With the use of Candida antarctica B, using hexane as solvent, (R)-pentyl 2-methylbutyrate was prepared in 2 h with c 40%, ee p 90%, and E = 35, while Thermomyces lanuginosus leads to c 18%, ee p 91%, and E = 26. The (S)-enantiomer was obtained by the use of Candida rugosa or Rhizopus oryzae (2-h reaction, c 34% and 35%, ee p 75 and 49%, and E = 10 and 4, respectively). Under optimal conditions, the effect of the solvent, the molar ratio, and the nucleophile were evaluated. © 2017 Wiley Periodicals, Inc.

  8. Structural analysis of co-evaporated In{sub 2}S{sub 3} and In{sub 2}S{sub 3}:V for solar cell absorber applications

    Energy Technology Data Exchange (ETDEWEB)

    Waegele, Leonard A.; Rata, Diana; Scheer, Roland [Institute of Physics, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 3, 06120 Halle (Saale) (Germany); Gurieva, Galina [Department Structure and Dynamics of Energy Materials, Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, 14109 Berlin (Germany)

    2017-06-15

    In this study we use co-evaporation to grow In{sub 2}S{sub 3} thin films on glass substrates and X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) to analyse the structural properties of annealed In{sub 2}S{sub 3} and V-doped In{sub 2}S{sub 3} for intermediate band solar cell application. We find co-evaporated In{sub 2}S{sub 3} to be polycrystalline on float glass and with improved crystallinity after annealing in S-atmosphere. We confirm that excessive incorporation of vanadium into the host structure is possible without formation of secondary crystalline phases. The analysis indicates a reduced crystalline quality after V doping. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Serum n-3 Tetracosapentaenoic Acid and Tetracosahexaenoic Acid Increase Following Higher Dietary α-Linolenic Acid but not Docosahexaenoic Acid.

    Science.gov (United States)

    Metherel, Adam H; Domenichiello, Anthony F; Kitson, Alex P; Lin, Yu-Hong; Bazinet, Richard P

    2017-02-01

    n-3 Tetracosapentaenoic acid (24:5n-3, TPAn-3) and tetracosahexaenoic acid (24:6n-3, THA) are believed to be important intermediates to docosahexaenoic acid (DHA, 22:6n-3) synthesis. The purpose of this study is to report for the first time serum concentrations of TPAn-3 and THA and their response to changing dietary α-linolenic acid (18:3n-3, ALA) and DHA. The responses will then be used in an attempt to predict the location of these fatty acids in relation to DHA in the biosynthetic pathway. Male Long Evans rats (n = 6 per group) were fed either a low (0.1% of total fatty acids), medium (3%) or high (10%) ALA diet with no added DHA, or a low (0%), medium (0.2%) or high (2%) DHA diet with a background of 2% ALA for 8 weeks post-weaning. Serum n-3 and n-6 polyunsaturated fatty acid (PUFA) concentrations (nmol/mL ± SEM) were determined by gas chromatography-mass spectrometry. Serum THA increases from low (0.3 ± 0.1) to medium (5.8 ± 0.7) but not from medium to high (4.6 ± 0.9) dietary ALA, while serum TPAn-3 increases with increasing dietary ALA from 0.09 ± 0.04 to 0.70 ± 0.09 to 1.23 ± 0.14 nmol/mL. Following DHA feeding, neither TPAn-3 or THA change across all dietary DHA intake levels. Serum TPAn-3 demonstrates a similar response to dietary DHA. In conclusion, this is the first study to demonstrate that increases in dietary ALA but not DHA increase serum TPAn-3 and THA in rats, suggesting that both fatty acids are precursors to DHA in the biosynthetic pathway.

  10. MLS/Aura L2 Nitric Acid (HNO3) Mixing Ratio V003

    Data.gov (United States)

    National Aeronautics and Space Administration — ML2HNO3 is the EOS Aura Microwave Limb Sounder (MLS) standard product for nitric acid derived from radiances measured by the 240 GHz radiometer at and below 10 hPa,...

  11. MLS/Aura Level 2 Nitric Acid (HNO3) Mixing Ratio V004

    Data.gov (United States)

    National Aeronautics and Space Administration — ML2HNO3 is the EOS Aura Microwave Limb Sounder (MLS) standard product for nitric acid derived from radiances measured by the 240 GHz radiometer at and below 10 hPa,...

  12. MLS/Aura L2 Nitric Acid (HNO3) Mixing Ratio V002

    Data.gov (United States)

    National Aeronautics and Space Administration — ML2HNO3 is the EOS Aura Microwave Limb Sounder (MLS) standard product for nitric acid derived from radiances measured by the 240 GHz radiometer at and below 10 hPa,...

  13. Determination of the 1s2{\\ell }2{{\\ell }}^{\\prime } state production ratios {{}^{4}P}^{o}/{}^{2}P, {}^{2}D/{}^{2}P and {{}^{2}P}_{+}/{{}^{2}P}_{-} from fast (1{s}^{2},1s2s\\,{}^{3}S) mixed-state He-like ion beams in collisions with H2 targets

    Science.gov (United States)

    Benis, E. P.; Zouros, T. J. M.

    2016-12-01

    New results are presented on the ratio {R}m={σ }{T2p}( {}4P)/{σ }{T2p}({}2P) concerning the production cross sections of Li-like 1s2s2p quartet and doublet P states formed in energetic ion-atom collisions by single 2p electron transfer to the metastable 1s2s {}3S component of the He-like ion beam. Spin statistics predict a value of R m = 2 independent of the collision system in disagreement with most reported measurements of {R}m≃ 1{--}9. A new experimental approach is presented for the evaluation of R m having some practical advantages over earlier approaches. It also allows for the determination of the separate contributions of ground- and metastable-state beam components to the measured spectra. Applying our technique to zero-degree Auger projectile spectra from 4.5 MeV {{{B}}}3+ (Benis et al 2002 Phys. Rev. A 65 064701) and 25.3 MeV {{{F}}}7+ (Zamkov et al 2002 Phys. Rev. A 65 062706) mixed state (1{s}2 {}1S,1s2s {}3S) He-like ion collisions with H2 targets, we report new values of {R}m=3.5+/- 0.4 for boron and {R}m=1.8+/- 0.3 for fluorine. In addition, the ratios of {}2D/{}2P and {{}2P}+/{{}2P}- populations from either the metastable and/or ground state beam component, also relevant to this analysis, are evaluated and compared to previously reported results for carbon collisions on helium (Strohschein et al 2008 Phys. Rev. A 77 022706) including a critical comparison to theory.

  14. 2-(5,7-Dimethyl-3-methylsulfanyl-1-benzofuran-2-ylacetic acid

    Directory of Open Access Journals (Sweden)

    Hong Dae Choi

    2008-08-01

    Full Text Available The title compound, C13H14O3S, was prepared by alkaline hydrolysis of ethyl 2-(5,7-dimethyl-3-methylsulfanyl-1-benzofuran-2-ylacetate. In the crystal structure, the carboxyl groups are involved in intermolecular O—H...O hydrogen bonds, which link the molecules into centrosymmetric dimers. These dimers are further packed into stacks along the a axis by weak C—H...π interactions.

  15. Characterization of Meldrum's acid derivative 5-(5-Ethyl-1,3,4-thiadiazol-2-ylamino)methylene-2,2-dimethyl-1,3-dioxane-4,6-dione by Raman and FT-IR spectroscopy and DFT calculations

    Science.gov (United States)

    de Toledo, T. A.; da Silva, L. E.; Teixeira, A. M. R.; Freire, P. T. C.; Pizani, P. S.

    2015-07-01

    In this study, the structural and vibrational properties of Meldrum's acid derivative 5-(5-Ethyl-1,3,4-thiadiazol-2-ylamino)methylene-2,2-dimethyl-1,3-dioxane-4,6-dione, C11H13N3O4S were studied combining experimental techniques such as Raman and FT-IR spectroscopy and density functional theory (DFT) calculations. The Raman and FT-IR spectra were recorded at room conditions in the regions from 80 to 3400 cm-1 and 400 to 4000 cm-1, respectively. Vibrational wavenumbers were predicted using DFT calculations with the hybrid functional B3LYP and basis set 6-31G(d,p). A comparison between experimental and theoretical data is provided for the Raman and FT-IR spectra. The descriptions of the normal modes were carried by means of potential energy distribution (PED).

  16. 2-arylureidobenzoic acids

    DEFF Research Database (Denmark)

    Valgeirsson, Jon; Nielsen, Elsebet Ø; Peters, Dan

    2003-01-01

    A series of 2-arylureidobenzoic acids (AUBAs) was prepared by a short and effective synthesis, and the pharmacological activity at glutamate receptors was evaluated in vitro and in vivo. The compounds showed noncompetitive antagonistic activity at the kainate receptor subtype GluR5. The most potent...... on the benzoic acid moiety (ring A), whereas ring B tolerated a variety of substituents, but with a preference for lipophilic substituents. The most potent compounds had a 4-chloro substituent on ring A and 3-chlorobenzene (6b), 2-naphthalene (8h), or 2-indole (8k) as ring B and had IC(50) values of 1.3, 1...

  17. The respective N-hydroxypyrazole analogues of the classical glutamate receptor ligands ibotenic acid and (RS)-2-amino-2-(3-hydroxy-5-methyl-4-isoxazolyl)acetic acid

    DEFF Research Database (Denmark)

    Clausen, Rasmus P; Hansen, Kasper B; Calí, Patrizia

    2004-01-01

    We have determined the pharmacological activity of N-hydroxypyrazole analogues (3a and 4a) of the classical glutamate receptor ligands ibotenic acid and (RS)-2-amino-2-(3-hydroxy-5-methyl-4-isoxazolyl)acetic acid (AMAA), as well as substituted derivatives of these two compounds. The pharmacological...... partial agonism to antagonism with increasing substituent size, substitution abolishes affinity for mglu1 and mglu4 receptors. Ligand- and receptor-based modelling approaches assist in explaining these pharmacological trends among the metabotropic receptors and suggest a mechanism of partial agonism...

  18. Stability Investigation of Ligand-Exchanged CdSe/ZnS-Y (Y = 3-Mercaptopropionic Acid or Mercaptosuccinic Acid through Zeta Potential Measurements

    Directory of Open Access Journals (Sweden)

    Ngoc Thuy Vo

    2016-01-01

    Full Text Available Quantum dots have been considered to be promising candidates for bioapplications because of their high sensitivity, rapid response, and reliability. The synthesis of high-quality quantum dots that can be dissolved in water and other biological media is a crucial step toward their further application in biology. Starting with a one-pot reaction and the successive ionic layer adsorption and reaction (SILAR method, we produced the CdSe/ZnS core/shell structure. Through a ligand-exchange mechanism, we coated the as-made CdSe/ZnS structure with 3-mercaptopropionic acid (MPA or mercaptosuccinic acid (MSA. Various techniques, including photoluminescence (PL, ultraviolet-visible (UV-Vis spectroscopy, transmission electron microscopy (TEM, X-ray diffraction (XRD, and Fourier transform infrared (FTIR spectroscopy, were utilized to characterize the ligand-coated CdSe/ZnS structure. The results show enhanced luminescence intensity, CdSe surface passivation by ZnS, and successful coating with MPA and MSA. The stability of quantum dots in solutions with different pH values was investigated by performing zeta potential measurements. The results revealed that the quantum dots shifted from displaying hydrophobic to hydrophilic behavior and could be connected with bioagents.

  19. Sensitization to heat by the polyamines and their analogs

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, D.J.; Gerner, E.W.

    1983-07-01

    The polyamines putrescine, spermidine, and spermine have been shown to sensitize Chinese hamster ovary (CHO) cells to the cytotoxic effects of elevated temperatures. This sensitization occurs in the order spermine greater than spermidine greater than putrescine. A series of homologs of the diamine putrescine demonstrated little variance in the degree of potentiation until a chain length equivalent to that of spermidine was employed (1,8-diaminooctane). Two compounds bearing structural similarities to spermidine gave rather different results when combined with heat. Methylglyoxal bis(guanylhydrazone) (MGBG), an antiproliferative drug, sensitized cells to heat, while S-2-(3-aminopropylamino)-ethyl phosphoric acid (WR-2721), a radioprotector, had no measureable effect on 43 degrees C-induced cytotoxicity. Together, these results point out the primary importance of two terminal amino groups separated by either carbon, or carbon and nitrogen, atoms in an aliphatic chain in the observed sensitization of heat-induced cytotoxicity by polyamines. These data suggest specific dimensional characteristics of the presumed negatively charged structure(s) with which the polyamines are interacting to elicit this effect.

  20. 4-Methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylic Acid. Peculiarities of Preparation, Structure, and Biological Properties

    Directory of Open Access Journals (Sweden)

    Igor V. Ukrainets

    2018-03-01

    Full Text Available In order to determine the regularities of the structure–analgesic activity relationship, the peculiarities of obtaining, the spatial structure, and biological properties of 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylic acid and some of its derivatives have been studied. Using nuclear magnetic resonance (NMR spectroscopy and X-ray diffraction analysis, it has been proven that varying the reaction conditions using alkaline hydrolysis of methyl 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylate makes it possible to successfully synthesize a monohydrate of the target acid, its sodium salt, or 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine. The derivatographic study of the thermal stability of 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylic acid monohydrate has been carried out; based on this study, the optimal conditions completely eliminating the possibility of unwanted decomposition have been proposed for obtaining its anhydrous form. It has been shown that 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine is easily formed during the decarboxylation of not only 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylic acid, but also its sodium salt, which is capable of losing СО2 both in rather soft conditions of boiling in an aqueous solution, and in more rigid conditions of dry heating. The NMR spectra of the compounds synthesized are given; their spatial structure is discussed. To study the biological properties of 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylic acid and its sodium salt, the experimental model of inflammation caused by subplantar introduction of the carrageenan solution in one of the hind limbs of white rats was used. The anti-inflammatory activity and analgesic effect were assessed by the degree of edema reduction and the ability to affect the pain response compared to the animals of control groups. According to the results of the tests performed, it has been found that after intraperitoneal injection

  1. One-electron capture into Li-like autoionising N4+ (1s2ln'l') configurations by metastable N5+ (1s2s3S) multicharged ions in collisions with He and H2, observed by electron spectrometry at 3.4 keV amu-1

    International Nuclear Information System (INIS)

    Bordenave-Montesquieu, A.; Benoit-Cattin, P.; Gleizes, A.

    1985-01-01

    One-electron capture into N 4+ (1s2ln'l') configurations, with n'=2 to 4, has been observed by electron spectrometry when a N 5+ (1s2s 3 S) multicharged ion beam encounters an He or H 2 target, at low collision velocity (upsilon=0.37 au) within single-collision conditions. Contributions of other 1s2l metastable states and of the 1s 2 ground state may be disregarded. A small indication of two-electron capture by 1s2s 3 S ions into (1s2s 3 S)3l3l' configurations is also seen. (author)

  2. Synthesis and Characterization of Ferroelectric Liquid Crystalline Organosiloxanes Containing 4-(4-undecanyloxy bi-phenyl-1-carboxyloxyphenyl (2S,3S-2-chloro-3-methylvalerate and 4-(4-undecanyloxybenzoyloxybiphenyl (2S,3S-2-chloro-3-methylvalerate

    Directory of Open Access Journals (Sweden)

    Chih-Hung Lin

    2013-10-01

    Full Text Available A series of new organosiloxane ferroelectric liquid crystalline (FLC materials have been synthesized, and their mesomorphic and physical properties have been characterized. Four new disiloxanes and trisiloxanes, containing biphenyl 4-hydroxybenzoate and phenyl 4-hydroxybiphenylcarboxylate as mesogenic units and eleven methylene unit as spacers and (2S,3S-2-chloro-3-methylvalerate unit as chiral end groups. The molecule, using three phenyl ring as a mesogenic unit, formulates much wider liquid crystalline phase temperature ranges than that of a two phenyl ring unit. The phenyl arrangement differences of mesogenic unit result in the greater differences of the liquid crystal phase formation. The siloxane molecule induction is helpful to the more regular smectic phase formation and smectic phase stabilization, such as chiral SC (SC* and SB phases. The siloxane molecule is helpful to reduce the phase transition temperature and broaden the liquid crystal temperature range of the SC* phase and, simultaneously, it will not induce chain crystallization phenomenon and dilute the Ps value. The synthesis and characterization of the new FLCs materials, which exhibit a room temperature SC* phase and higher spontaneous polarization are presented.

  3. Investigations with beagles about toxicity and radioprotective effect of the chemical radioprotection substance WR 2721

    International Nuclear Information System (INIS)

    Wagner, M.; Sedlmeier, H.; Wustrow, T.; Messerschmidt, O.

    1980-01-01

    The toxicity of the chemical radioprotection substance WR 2721 (S-2-(3-aminopropylamino)ethyl-thiophosphate) was examined in 25 beagles. The study showed that the toxicity of the substance increases as the dose gets higher. Between the doses 200 and 250 mg/kg of body weight, the increase of toxicity was significantly greater than could be expected on the basis of the dose difference. Until a dose of 200 mg/kg, the authors found no side effects which would have disturbed vital functions, but higher doses led to marked symptoms of intoxication. (orig.) [de

  4. Monooxygenase system in Guerin’s carcinoma of rats under conditions of ω-3 polyunsaturated fatty acids administration

    Directory of Open Access Journals (Sweden)

    M. M. Marchenko

    2016-08-01

    Full Text Available The aim of the study was to determine the variations of function in components of monooxygenase system (MOS of rat Guerin’s carcinoma under ω-3 polyunsaturated fatty acids (PUFAs administration. The activity of Guerin’s carcinoma microsomal NADH-cytochrome b5 reductase, the content and the rate of cytochrome b5 oxidation-reduction, the content and the rate of cytochrome Р450 oxidation-reduction have been investigated in rats with tumor under conditions of ω-3 PUFAs administration. ω-3 PUFAs supplementation before and after transplantation of Guerin’s carcinoma resulted in the increase of NADH-cytochrome b5 reductase activity and decrease of cytochrome b5 level in the Guerin’s carcinoma microsomal fraction in the logarithmic phases of carcinogenesis as compared to the tumor-bearing rats. Increased activity of NADH-cytochrome b5 reductase facilitates higher electron flow in redox-chain of MOS. Under decreased cytochrome b5 levels the electrons are transferred to oxygen, which leads to heightened generation of superoxide (O2•- in comparison to control. It was shown, that the decrease of cytochrome P450 level in the Guerin’s carcinoma microsomal fraction in the logarithmic phases of oncogenesis under ω-3 PUFAs administration may be associated with its transition into an inactive form – cytochrome P420. This decrease in cytochrome P450 coincides with increased generation of superoxide by MOS oxygenase chain.

  5. SL(2, Z) invariant rotating (m, n) strings in AdS_3 x S"3 with mixed flux

    International Nuclear Information System (INIS)

    Barik, M.S.P.; Panigrahi, Kamal L.; Khouchen, Malak; Kluson, Josef

    2017-01-01

    We study rigidly rotating and pulsating (m, n) strings in AdS_3 x S"3 with mixed three form flux. The AdS_3 x S"3 background with mixed three form flux is obtained in the near horizon limit of SL(2, Z)-transformed solution, corresponding to the bound state of NS5-branes and fundamental strings. We study the probe (m, n)-string in this background by solving the manifest SL(2, Z)-covariant form of the action. We find the dyonic giant magnon and single spike solutions corresponding to the equations of motion of a probe string in this background and find various relationships among the conserved charges. We further study a class of pulsating (m, n) string in AdS_3 with mixed three form flux. (orig.)

  6. Kinetics and Mechanism of Bioactivation via S-Oxygenation of Anti-Tubercular Agent Ethionamide by Peracetic Acid.

    Science.gov (United States)

    Chipiso, Kudzanai; Logan, Isabelle E; Eskew, Matthew W; Omondi, Benard; Simoyi, Reuben H

    2016-10-11

    The kinetics and mechanism of the oxidation of the important antitubercular agent, ethionamide, ETA (2-ethylthioisonicotinamide), by peracetic acid (PAA) have been studied. It is effectively a biphasic reaction with an initial rapid first phase of the reaction which is over in about 5 s and a second slower phase of the reaction which can run up to an hour. The first phase involves the addition of a single oxygen atom to ethionamide to form the S-oxide. The second phase involves further oxidation of the S-oxide to desulfurization of ETA to give 2-ethylisonicotinamide. In contrast to the stability of most organosulfur compounds, the S-oxide of ETA is relatively stable and can be isolated. In conditions of excess ETA, the stoichiometry of the reaction was strictly 1:1: CH 3 CO 3 H + Et(C 5 H 4 )C(═S)NH 2 → CH 3 CO 2 H + Et(C 5 H 4 )C(═NH)SOH. In this oxidation, it was apparent that only the sulfur center was the reactive site. Though ETA was ultimately desulfurized, only the S-oxide was stable. Electrospray ionization (ESI) spectral analysis did not detect any substantial formation of the sulfinic and sulfonic acids. This suggests that cleavage of the carbon-sulfur bond occurs at the sulfenic acid stage, resulting in the formation of an unstable sulfur species that can react further to form more stable sulfur species. In this oxidation, no sulfate formation was observed. ESI spectral analysis data showed a final sulfur species in the form of a dimeric sulfur monoxide species, H 3 S 2 O 2 . We derived a bimolecular rate constant for the formation of the S-oxide of (3.08 ± 0.72) × 10 2 M -1 s -1 . Oxidation of the S-oxide further to give 2-ethylisonicotinamide gave zero order kinetics.

  7. Ca and S K-edge XANES studies of calcite-acid mine water interactions

    International Nuclear Information System (INIS)

    Myneni, S.C.B.; Perera, R.C.C.

    1997-01-01

    Heavy metal-rich acidic waters (SO 4 2- , AsO 4 3- , SeO 4 2- , Fe 2+ , Fe 3+ , Al 3+ , Cu 2+ , Zn 2+ , Cd 2+ ) and related ochreous coatings are common around abandoned sulfide and coal mine sites. This is mainly caused by the natural weathering of pyrite (FeS 2 ), arsenopyrite (FeAsS), and other metal sulfide containing shales. Acid generation in the case of pyrite can be explained by a general reaction: FeS 2 + 3.5 O 2 + H 2 O ↔ Fe 2+ + SO 4 2- + 2H + . Also, these low pH waters interact with the soils, and mobilize their soluble elements. One of the common remediation strategies is to allow these acid waters to react with limestone (CaCO 3 -rich rock) and neutralize the pH and precipitate out soluble metals. Yet, the associated problem is the precipitation of Fe and Al oxides and hydroxy sulfate coatings on limestone surfaces, which block calcite reactive sites, and make them ineffective a few hours after initiation of treatment. The main objectives of this research are to examine: (1) the chemistry of limestone surface coatings, and (2) their toxic metal uptake and the conditions that inhibit their formation. Previous molecular studies using X-ray diffraction, and vibrational spectroscopy on limestone surface coatings (sampled from Athens, OH) indicate that the surface-most layer (the layer in contact with water) is composed of schwertmannite (Fe(III)-hydroxy sulfate) like phases. However, white, X-ray amorphous; Al-, sulfate- and carbonate-rich; and Ca-poor phases appeared at the interface between the limestone and the iron oxide coatings. The structure, morphology, and coordination chemistry of component major and trace elements of these white precipitate phases have not previously been examined

  8. Boosted surface acidity in TiO{sub 2} and Al{sub 2}O{sub 3}-TiO{sub 2} nanotubes as catalytic supports

    Energy Technology Data Exchange (ETDEWEB)

    Camposeco, R. [Molecular Engineering Program, Mexican Institute of Petroleum, 07730, México, D.F. (Mexico); Department of Chemistry, UAM-A, 55534, México, D.F. (Mexico); Castillo, S., E-mail: scastill@imp.mx [Molecular Engineering Program, Mexican Institute of Petroleum, 07730, México, D.F. (Mexico); Department of Chemical Engineering, ESIQIE-IPN, 75876, México, D.F. (Mexico); Mejía-Centeno, Isidro; Navarrete, J.; Nava, N. [Molecular Engineering Program, Mexican Institute of Petroleum, 07730, México, D.F. (Mexico)

    2015-11-30

    Graphical abstract: - Highlights: • Surface acidity of NTs was modified by adding alumina. • Brönsted acid sites remain constant but Lewis acid sites are increased remarkably. • IR characterization by lutidine and pyridine confirms the surface acidity of NTs. • 98% of NO conversion was reached between 380 and 480 °C on NT-5Al. • The boosted surface acidity of NT-Al improves the catalytic activity for SCR-NO. - Abstract: In this study, titanate nanotubes (NT) and titanate nanotubes with alumina (NT-Al) were studied as solid acid catalytic supports to show the relationship between the kind of acidity and catalytic activity. The supports were characterized by XRD, TEM, FTIR, XPS, and tested in the SCR-NO with NH{sub 3}. It was found that the amount of Brönsted acid sites was maintained and the Lewis acid sites were significantly affected by the addition of alumina (1, 3, 5 and 10 wt.%); such acidity was higher than that of the titanate nanotubes (NT) by two-fold. To confirm the formation of titanate nanotubes and titanate nanotubes with alumina, transmission electron microscopy (TEM) was used. X-ray diffraction (XRD) revealed the formation of the H{sub 2}Ti{sub 4}O{sub 9}·H{sub 2}O phase. All NT and NT-Al supports presented catalytic activity to remove NO with NH{sub 3} under lean conditions, confirming the presence of an important amount of Brönsted and Lewis acid sites in both NT and NT-Al supports.

  9. Two novel penetrating coordination polymers based on flexible S-containing dicarboxylate acid with sensing properties towards Fe3+ and Cr2O72- ions

    Science.gov (United States)

    Chen, Zhiwei; Mi, Xiuna; Wang, Suna; Lu, Jing; Li, Yunwu; Li, Dacheng; Dou, Jianmin

    2018-05-01

    Two new coordination polymers (CPs), namely, {[Zn(L)(bpp)]·DMF}n (1) and {[Zn(L)(bpe)]·DMF}n (2) (L = 2,2'-[benzene-1,3-diylbis(methanediylsulfanediyl)]dibenzoic acid, bpp= 1,3-bis(4-pyridyl)propane, bpe = 1,2-Bis(4-pyridyl)ethylene, DMF = N,N-Dimethylformamide), have been solvothermally synthesized and fully characterized. Complex 1 displays a 2D→2D three-fold"false" interpenetrating structure while complex 2 possesses a novel 3-D 4-connected structure with fascinating self-penetrating moieties. The luminescence studies reveal that these complexes exhibited excellent selectivity for Fe3+ and Cr2O72- ions in DMF. The sensing mechanism was investigated through PXRD, XPS , EDS mapping measurements, and discussed in details.

  10. Synthesis and pharmacological characterization of the selective GluK1 radioligand (S)-2-amino-3-(6-[3H]-2,4-dioxo-3,4-dihydrothieno.3,2-d] pyrimidin1(2H)- yl) propanoic acid ([3H]-NF608)

    DEFF Research Database (Denmark)

    Alcaide, Anna; Marconi, Laura; Marek, Ales

    2016-01-01

    The kainic acid receptors belong to the class of ionotropic glutamate receptors and comprise five subunits named GluK1-5. Radioligands are essential tools for use in binding assays aimed at ligand-receptor structure-activity-relationship studies. Previous work has led to the synthesis of GluK1...... radioligands [H-3]SYM2081, [H-3]-UBP310 and [H-3]-ATPA, however all strategies were work-intensive and thus not attractive. Herein, we report the synthesis of [H-3]-NF608 and subsequent pharmacological evaluation at homomeric recombinant rat GluK1 receptors. Binding affinities of a series of standard GluK1...... ligands were shown to be in line with previously reported affinities obtained by use of already reported radioligands....

  11. One-step preparation of [2,3-{sup 3}H]1-aminocyclo-propanecarboxylic acid: a useful ligand for strychnine-insensitive glycine receptors

    Energy Technology Data Exchange (ETDEWEB)

    Lewin, A.H.; Lamb, P.B. [Research Triangle Inst., Research Triangle Park, NC (United States); Popik, P.; Skolnick, P. [National Insts. of Health, Bethesda, MD (United States)

    1994-11-01

    Catalytic hydrogenation of 1-aminocyclopropenecarboxylic acid under tritium gas afforded [2,3-{sup 3}H]1-aminocyclopropanecarboxylic acid with specific activity 26 Ci/mmol, determined by a combination of {sup 1}H and {sup 3}H NMR. Pilot radioligand binding assays indicate this compound will be a useful prove for the NMDA receptor-associated strychnine-insensitive glycine receptor. (author).

  12. The study of antimicrobial activity of 2-((4-R-3-(morpholinomethylene-4H-1,2,4-triazole-5-ylthioacetic acid salts

    Directory of Open Access Journals (Sweden)

    R. О. Shcherbyna

    2016-08-01

    Full Text Available The purpose of the work was to study the antimicrobial activity of 2-((4-R-3-(morfolinomethylene-4H-1,2,4-triazole-5-ylthio acetic acid salts by "hanging drop" and “serial dilution” methods in broth (limiting concentration option and establish some patterns of "structure – action" depending. Materials and methods. The objects of research were 9 new compounds of 2-((4-R-3-(morfolinomethylene-4H-1,2,4-triazole-5-ylthio acetic acid salts. These compounds are the crystal substances which are odorless, soluble in water and organic solvents. To achieve a more objective picture of the research we applied two methods: "hanging drop" and “serial dilution” in broth (limiting concentration option. To study the effectiveness of substances we used the test cultures of E. coli, Salmonella typhymurium, Staphylococcus epidermidis, P. aeruginosa. Results and discussion. In the study we have found that 2-((4-R-3-(morfolinomethylene-4H-1,2,4-triazole-5-ylthio acetic acid salts can differently inhibit the growth of test cultures. The results show that the data obtained by two methods correlated with each other. Thus, the 2-((4-R-3-(morfolinomethylene-4H-1,2,4-triazole-5-ylthio acetic acid salts are active against most strains of E. Coli. and Salmonella typhymurium. Analyzing the impact of 2-((4-R-3-(morfolinomethylene-4H-1,2,4-triazole-5-ylthio acetic acid salts we have noted that the replacement of the phenyl radical (PKR-135, 139 on the free amino group at N4 nitrogen of 1,2,4- triazole cycle (PKR-173, 177 leads to the disappearance of antimicrobial activity against the studied strains. It was established that the transition from morfolin cation (PKR-133 to the piperydyn cation (PKR-134 in the molecules of 2-((4-phenyl-3-(morfolinometylen-4H-1,2,4-triazole-5-yl thio acetic acid is accompanied by a significant increase in antimicrobial effect. It was interesting that among all the cations in the molecules of 2-((4-amino-3-(morfolinometylen-4H-1,2

  13. Neutral Guest Capture via Lewis Acid/Base Molecular Square Receptors. X-ray Crystal Structure of {Cyclobis[(cis-(dppp)Pt(4-ethynylpyridyl)(2))(cis- (PEt(3))(2)Pt)]Ag(2)}(+6)(phenazine)- ((-)OSO(2)CF(3))(6).

    Science.gov (United States)

    Whiteford, Jeffery A.; Stang, Peter J.; Huang, Songping D.

    1998-10-19

    Interaction of {cyclobis[(cis-(dppp)Pt(4-ethynylpyridyl)(2))(cis-(L)M)]Ag(2)}(+6)((-)OSO(2)CF(3))(6), where M = Pt(II) or Pd(II) and L = dppp or 2PEt(3), with pyridine, pyrazine, phenazine, or 4,4'-dipyridyl ketone results in coordination Lewis acid/base host-guest assemblies via the "pi-tweezer effect" and mono or bis neutral guest coordination. All host-guest complexes are air stable microcrystalline solids with decomposition points greater than 170 degrees C. The homometallic Pt(II) receptors are more stable than the heteroaromatic Pt(II)-Pd(II) receptors toward heteratom-containing aromatic guests. The X-ray crystal structure of the host-guest complex {cyclobis[(cis-(dppp)Pt(4-ethynylpyridyl)(2))(cis-(PEt(3))(2)Pt)]Ag(2)}(+6)(phenazine)((-)OSO(2)CF(3))(6) is reported. The crystals with the empirical formula C(62)H(68)AgF(9)N(3)O(9)P(4)Pt(2)S(3) are triclinic P&onemacr; with a = 12.3919(8) Å, b = 17.160(1) Å, c = 18.932(1) Å, alpha = 90.892(1) degrees, beta = 97.127(1) degrees, gamma = 89.969(1) degrees, and Z = 2.

  14. Heterocycles [h]-Fused Onto 4-Oxoquinoline-3-Carboxylic Acid, Part VIII [1]. Convenient Synthesis and Antimicrobial Properties of Substituted Hexahydro[1,4]diazepino[2,3-h]quinoline-9-carboxylic acid and Its Tetrahydroquino[7,8-b]benzodiazepine Analog

    Directory of Open Access Journals (Sweden)

    Yusuf M. Al-Hiari

    2008-11-01

    Full Text Available [1,4]Diazepino[2,3-h]quinolone carboxylic acid 3 and its benzo-homolog tetrahydroquino[7,8-b]benzodiazepine-3-carboxylic acid 5 were prepared via PPAcatalyzed thermal lactamization of the respective 8-amino-7-substituted-1,4-dihydroquinoline-3-carboxylic acid derivatives 8, 10. The latter compounds were obtained by reduction of their 8-nitro-7-substituted-1,4-dihydroquinoline-3-carboxylic acid precursors 7, 9 which, in turn, were prepared by reaction of 7-chloro-1-cyclopropyl-6-fluoro-8-nitro-1,4-dihydroquinoline-3-carboxylic acid (6 with each of β-alanine and anthranilic acid. All intermediates and target compounds were characterized using elemental analysis, NMR, IR and MS spectral data. The prepared targets and the intermediates have shown interesting antibacterial activity mainly against Gram positive strains. In particular, compound 8 showed good activity against S. aureus (MIC = 0.39 μg/mL and B. subtilis (MIC = 0.78 μg/mL. Compounds 5a and 9 have also displayed good antifungal activity against C. albicans (MIC = 1.56 μg/mL and 0.78 μg/mL, respectively. None of the compounds tested showed any anticancer activity against solid breast cancer cell line MCF-7 cells or a human breast adenocarcinoma cell line.

  15. Synthesis of 1-Methyl-3-oxo-7-oxabicyclo[2.2.1]hept-5-ene-2-carboxylic Acid Methyl Ester

    Directory of Open Access Journals (Sweden)

    Gil Valdo José da Silva

    2005-11-01

    Full Text Available A simple and efficient method for the preparation of 1-methyl-3-oxo-7- oxabicyclo[2.2.1]hept-5-en-2-carboxylic acid methyl ester (1 is described. The first step is a highly regioselective Diels-Alder reaction between 2-methylfuran and methyl-3-bromo- propiolate. A remarkably difficult ketal hydrolysis reaction was effected by treatment with HCl, a simple reagent that was shown to be more efficient, in this case, than commonly used more elaborate methods.

  16. Electronic structure of shandite Co3Sn2S2

    Science.gov (United States)

    Dedkov, Y. S.; Holder, M.; Molodtsov, S. L.; Rosner, H.

    2008-03-01

    The electronic structure of shandite Co3Sn2S2 was determined by photoelectron spectroscopy and compared with ab initio band structure calculations. Presented results give evidence that this compound has half-metallic ferromagnetic properties.

  17. CuInS2 thin films obtained through the annealing of chemically deposited In2S3-CuS thin films

    International Nuclear Information System (INIS)

    Pena, Y.; Lugo, S.; Calixto-Rodriguez, M.; Vazquez, A.; Gomez, I.; Elizondo, P.

    2011-01-01

    In this work, we report the formation of CuInS 2 thin films on glass substrates by heating chemically deposited multilayers of copper sulfide (CuS) and indium sulfide (In 2 S 3 ) at 300 and 350 deg. C in nitrogen atmosphere at 10 Torr. CIS thin films were prepared by varying the CuS layer thickness in the multilayers with indium sulfide. The XRD analysis showed that the crystallographic structure of the CuInS 2 (JCPDS 27-0159) is present on the deposited films. From the optical analysis it was estimated the band gap value for the CIS film (1.49 eV). The electrical conductivity varies from 3 x 10 -8 to 3 Ω -1 cm -1 depending on the thickness of the CuS film. CIS films showed p-type conductivity.

  18. Omega-3 polyunsaturated fatty acid has an anti-oxidant effect via the Nrf-2/HO-1 pathway in 3T3-L1 adipocytes

    International Nuclear Information System (INIS)

    Kusunoki, Chisato; Yang, Liu; Yoshizaki, Takeshi; Nakagawa, Fumiyuki; Ishikado, Atsushi; Kondo, Motoyuki; Morino, Katsutaro; Sekine, Osamu; Ugi, Satoshi; Nishio, Yoshihiko; Kashiwagi, Atsunori; Maegawa, Hiroshi

    2013-01-01

    Highlights: ► Omega-3 PUFA has a direct anti-oxidant effect in adipocytes. ► EPA and DHA induce HO-1 expression in 3T3-L1 adipocytes. ► Omega-3 PUFA and its end-product, 4-HHE, activates the Nrf-2/HO-1 pathway. ► Omega-3 PUFA protects against oxidative stress-induced cytotoxicity. -- Abstract: Oxidative stress is produced in adipose tissue of obese subjects and has been associated with obesity-related disorders. Recent studies have shown that omega-3 polyunsaturated fatty acid3-PUFA) has beneficial effects in preventing atherosclerotic diseases and insulin resistance in adipose tissue. However, the role of ω3-PUFA on adipocytes has not been elucidated. In this study, 3T3-L1 adipocytes were treated with ω3-PUFA and its metabolites, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), or 4-hydroxy hexenal (4-HHE). ω3-PUFA and its metabolites dose-dependently increased mRNA and protein levels of the anti-oxidative enzyme, heme oxygenase-1 (HO-1); whereas no changes in the well-known anti-oxidant molecules, superoxide dismutase, catalase, and glutathione peroxidase, were observed. Knockdown of nuclear factor erythroid 2-related factor 2 (Nrf-2) significantly reduced EPA, DHA or 4-HHE-induced HO-1 mRNA and protein expression. Also, pretreatment with ω3-PUFA prevented H 2 O 2 -induced cytotoxicity in a HO-1 dependent manner. In conclusion, treatment with EPA and DHA induced HO-1 through the activation of Nrf-2 and prevented oxidative stress in 3T3-L1 adipocytes. This anti-oxidant defense may be of high therapeutic value for clinical conditions associated with systemic oxidative stress.

  19. Role of protein-glutathione contacts in defining glutaredoxin-3 [2Fe-2S] cluster chirality, ligand exchange and transfer chemistry.

    Science.gov (United States)

    Sen, Sambuddha; Cowan, J A

    2017-10-01

    Monothiol glutaredoxins (Grx) serve as intermediate cluster carriers in iron-sulfur cluster trafficking. The [2Fe-2S]-bound holo forms of Grx proteins display cysteinyl coordination from exogenous glutathione (GSH), in addition to contact from protein-derived Cys. Herein, we report mechanistic studies that investigate the role of exogenous glutathione in defining cluster chirality, ligand exchange, and the cluster transfer chemistry of Saccharomyces cerevisiae Grx3. Systematic perturbations were introduced to the glutathione-binding site by substitution of conserved charged amino acids that form crucial electrostatic contacts with the glutathione molecule. Native Grx3 could also be reconstituted in the absence of glutathione, with either DTT, BME or free L-cysteine as the source of the exogenous Fe-S ligand contact, while retaining full functional reactivity. The delivery of the [2Fe-2S] cluster to Grx3 from cluster donor proteins such as Isa, Nfu, and a [2Fe-2S](GS) 4 complex, revealed that electrostatic contacts are of key importance for positioning the exogenous glutathione that in turn influences the chiral environment of the cluster. All Grx3 derivatives were reconstituted by standard chemical reconstitution protocols and found to transfer cluster to apo ferredoxin 1 (Fdx1) at rates comparable to native protein, even when using DTT, BME or free L-cysteine as a thiol source in place of GSH during reconstitution. Kinetic analysis of cluster transfer from holo derivatives to apo Fdx1 has led to a mechanistic model for cluster transfer chemistry of native holo Grx3, and identification of the likely rate-limiting step for the reaction.

  20. Synthesis and some properties of hydrogen phosphites M3(H2PO3)3, where M = Ga, V, Fe, or In

    International Nuclear Information System (INIS)

    Zakharova, B.S.; Tarnopol'skij, V.A.; Chudinova, N.N.

    2001-01-01

    The conditions on production and the properties of the acid phosphites M 3 (H 2 PO 3 ) 3 (M = Ga, V, Fe, In) are demonstrated. The compounds were investigated by X-ray diffraction, thermal gravimetric analysis, IR spectroscopy and conductometry. Interaction of M 2 O 3 (M = Ga, V, Fe, In) with the melt of phosphorous acid was studied in the P : M = 1. 5 : 1 - 10 : 1 interval of compositions. The lattice parameters are given, the hypothesis on the available of superstructure in the M 3 (H 2 PO 3 ) 3 compounds is corroborated. From the measurements the proton conductivity in vanadium and indium phosphites is comprised of 2.5 x 10 -5 and 1.9 x 10 8- S/cm correspondingly. Acid vanadium and indium phosphites are behaved similarly during heating. The limit of thermal stability of the acid phosphites V(H 2 PO 3 ) 3 , V(H 2 PO 3 ) 3 grows [ru

  1. Detection of endogenous DNA adducts, O-carboxymethyl-2'-deoxyguanosine and 3-ethanesulfonic acid-2'-deoxycytidine, in the rat stomach after duodenal reflux.

    Science.gov (United States)

    Terasaki, Masaru; Totsuka, Yukari; Nishimura, Koichi; Mukaisho, Ken-Ichi; Chen, Kuan-Hao; Hattori, Takanori; Takamura-Enya, Takeji; Sugimura, Takashi; Wakabayashi, Keiji

    2008-09-01

    The endogenous DNA adducts O(6)-carboxymethyl-deoxyguanosine (O(6)-CM-dG) and 3-ethanesulfonic acid-deoxycytidine (3-ESA-dC) are produced from N-nitroso bile acid conjugates, such as N-nitrosoglycocholic acid (NO-GCA) and N-nitrosotaurocholic acid (NO-TCA), respectively. Formation of these DNA adducts in vivo was here analyzed by 32P-postlabeling in the glandular stomach of rats subjected to duodenal content reflux surgery. In this model, all duodenal contents, including bile acid conjugates, flow back from the jejunum into the gastric corpus. The levels of O(6)-CM-dG found at 4 and 8 weeks after surgery were 40.9 +/- 9.4 and 56.3 +/- 3.2 per 10(8) nucleotides, respectively, whereas the sham operation groups had values of 5.8 +/- 2.3 and 5.9 +/- 0.5 per 10(8) nucleotides. Moreover, adduct spots corresponding to 3-ESA-dC were detected in both duodenal reflux and sham operation groups and levels in the duodenal reflux groups were around four-fold elevated at 11.2 +/- 1.0 and 8.9 +/- 1.0 per 10(8) nucleotides after 4 and 8 weeks, respectively. When the duodenal reflux animals were treated with a nitrite trapping agent, thiazolidine- 4-carboxylic acid (thioproline, TPRO), the levels of O(6)-CM-dG and 3-ESA-dC were reduced to the same levels as in the sham operation animals. These observations suggest that NO-TCA and NO-GCA are formed by nitrosation of glycocholic acid and taurocholic acid, respectively, and these nitroso compounds produce DNA adducts in the glandular stomach of rats subjected to duodenal content reflux surgery.

  2. (S-2-(4-Chlorobenzoyl-1,2,3,4-tetrahydrobenzo[e]pyrazino[1,2-a][1,4]diazepine-6,12(11H,12aH-dione—Synthesis and Crystallographic Studies

    Directory of Open Access Journals (Sweden)

    Adam Mieczkowski

    2017-10-01

    Full Text Available (S-2-(4-Chlorobenzoyl-1,2,3,4-tetrahydrobenzo[e]pyrazino[1,2-a][1,4]diazepine-6,12(11H,12aH-dione was obtained in a three-step, one-pot synthesis, starting from optically pure (S-2-piperazine carboxylic acid dihydrochloride. Selective acylation of the β-nitrogen atom followed by condensation with isatoic anhydride and cyclization with HATU/DIPEA to a seven-member benzodiazepine ring, led to the tricyclic benzodiazepine derivative. Crystallographic studies and initial biological screening were performed for the title compound.

  3. Synthesis and physicochemical properties of the furan dicarboxylic acid, 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid, an inhibitor of plasma protein binding in uraemia.

    Science.gov (United States)

    Costigan, M G; Gilchrist, T L; Lindup, W E

    1996-06-01

    The furan dicarboxylic acid, 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid (5-propyl FPA) accumulates in the plasma of patients with chronic renal failure and is a major contributor to the drug binding defect of uraemic plasma. This acid has also been implicated in several other aspects of the uraemic syndrome: anaemia, irregularities of thyroid function, neurological symptoms and inhibition of active tubular secretion. The acid is not commercially available and its synthesis, starting with Meldrum's acid and methyl succinyl chloride, is described. The pKa values were measured by titration and values of 3.2 and 3.6 respectively were assigned to the carboxylic acid groups attached directly to the ring at position 3 and at position 2 (on the side-chain). The partition coefficient (log P) between hydrochloric acid and octanol was 1.2 and the distribution coefficient (log D; octanol-phosphate buffer pH 7.4) was -0.59. The pKa values and the degree of hydrophobic character of 5-propyl FPA are consistent with those of other protein-bound acids which undergo active tubular secretion by the kidney and this substance may serve as an endogenous marker for the effects of drugs and disease on this process.

  4. Solution-Processed hybrid Sb2 S3 planar heterojunction solar cell

    Science.gov (United States)

    Huang, Wenxiao; Borazan, Ismail; Carroll, David

    Thin-film solar cells based on inorganic absorbers permit a high efficiency and stability. Among or those absorber candidates, recently Sb2S3 has attracted extensive attention because of its suitable band gap (1.5eV ~1.7 eV) , strong optical absorption, low-cost and earth-abundant constituents. Currently high-efficiency Sb2S3 solar cells have absorber layer deposited on nanostructured TiO2 electrodes in combination with organic hole transport material (HTM) on top. However it's challenging to fill the nanostructured TiO2 layer with Sb2S3 and subsequently by HTM, this leads to uncovered surface permits charge recombination. And the existing of Sb2S3/TiO2/HTM triple interface will enhance the recombination due to the surface trap state. Therefore, a planar junction cell would not only have simpler structure with less steps to fabricate but also ideally also have a higher open circuit voltage because of less interface carrier recombination. By far there is limited research focusing on planar Sb2S3 solar cell, so the feasibility is still unclear. Here, we developed a low-toxic solution method to fabricate Sb2S3 thin film solar cell, then we studied the morphology of the Sb2S3 layer and its impact to the device performance. The best device with a structure of FTO/TiO2/Sb2S3/P3HT/Ag has PCE over 5% which is similar or higher than yet the best nanostructure devices with the same HTM. Furthermore, based on solution engineering and surface modification, we improved the Sb2S3 film quality and achieved a record PCE. .

  5. 2-(5-Fluoro-3-isopropylsulfanyl-7-methyl-1-benzofuran-2-ylacetic acid

    Directory of Open Access Journals (Sweden)

    Hong Dae Choi

    2012-04-01

    Full Text Available The title compound, C14H15FO3S, was prepared by alkaline hydrolysis of ethyl 2-(5-fluoro-3-isopropylsulfanyl-7-methyl-1-benzofuran-2-ylacetate. In the crystal, molecules are linked via pairs of O—H...O hydrogen bonds, forming inversion dimers. These dimers are connected by weak C—H...O hydrogen bonds.

  6. 5-Acetamido-3,5-dideoxy-L-glycero-L-manno-non-2-ulosonic acid-containing O-polysaccharide from marine bacterium Pseudomonas glareae KMM 9500T.

    Science.gov (United States)

    Kokoulin, Maxim S; Kalinovsky, Anatoly I; Romanenko, Lyudmila A; Mikhailov, Valery V

    2018-05-22

    The O-polysaccharide was isolated from the lipopolysaccharide of a marine bacterium Pseudomonas glareae KMM 9500 T and studied by chemical methods along with 1D and 2D 1 H and 13 C NMR spectroscopy including 1 H, 1 H-TOCSY, 1 H, 1 H-COSY, 1 H, 1 H-ROESY, 1 H, 13 C-HSQC and 1 H, 13 C-HMBC experiments. The O-polysaccharide was found to consist of linear tetrasaccharide repeating units constituted by D-glucuronic acid (D-GlcA), L-rhamnose (L-Rha), D-glucose (D-Glc) and 5-acetamido-7,9-O-[(S)-1-carboxyethylidene]-3,5-dideoxy-L-glycero-L-manno-non-2-ulosonic acid (Sug7,9(S-Pyr)), partially O-acetylated at position 8 (∼70%): →4)-α-D-GlcpA-(1→3)-β-L-Rhap-(1→4)-β-D-Glcp-(1→4)-β-Sugp8Ac(∼70%)7,9(S-Pyr)-(2→. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Synthesis, Antibacterial and Antitubercular Activities of Some 5H-Thiazolo[3,2-a]pyrimidin-5-ones and Sulfonic Acid Derivatives

    Directory of Open Access Journals (Sweden)

    Dong Cai

    2015-09-01

    Full Text Available A series of 5H-thiazolo[3,2-a]pyrimidin-5-ones were synthesized by the cyclization reactions of S-alkylated derivatives in concentrated H2SO4. Upon treatment of S-alkylated derivatives at different temperatures, intramolecular cyclization to 7-(substituted phenylamino-5H-thiazolo[3,2-a]pyrimidin-5-ones or sulfonation of cyclized products to sulfonic acid derivatives occurred. The structures of the target compounds were confirmed by IR, 1H-NMR, 13C-NMR and HRMS studies. The compounds were evaluated for their preliminary in vitro antibacterial activity against some Gram-positive and Gram-negative bacteria and screened for antitubercular activity against Mycobacterium tuberculosis by the broth dilution assay method. Some compounds showed good antibacterial and antitubercular activities.

  8. Isolation of 3-amino-4-nitrobenzyl acetate: evidence of an undisclosed impurity in 5-amino-2-nitrobenzoic acid

    Directory of Open Access Journals (Sweden)

    Brandon Quillian

    2015-06-01

    Full Text Available Yellow crystals of the title compound 3-amino-4-nitrobenzyl acetate, C9H10N2O4, were isolated from the reaction of acetic anhydride with (5-amino-2-nitrophenylmethanol, prepared from reduction of commerically available 5-amino-2-nitrobenzoic acid with borane–THF. The molecule is essentially planar (r.m.s. deviation = 0.028 Å. The molecules are linked by intermolecular N—H...O hydrogen-bonding interactions between the carbonyl and amine groups, forming a zigzag chain along the b-axis direction lying in a plane parallel to (-102. The chains are stacked along the c axis by π–π interactions [centroid–centroid distances = 3.6240 (3 and 3.5855 (4 Å]. A strong intramolecular N—H...O hydrogen-bonding interaction is observed between the nitro group and the amine group [2.660 (2 Å].

  9. Convenient hydrothermal decomposition process for preparation of nanocrystalline mineral Cu3BiS3 and Pb1-xBi2x/3S

    International Nuclear Information System (INIS)

    Hu Junqing; Deng Bin; Wang Chunrui; Tang Kaibin; Qian Yitai

    2003-01-01

    Mineral nanocrystalline Cu 3 BiS 3 and Pb 1-x Bi 2x/3 S (or Bi 0.22 Pb 0.89 S 1.22 ) have been prepared at low synthetic temperature of 100-150 deg. C by convenient hydrothermal decomposition process. X-ray powder diffraction, transmission electron microscopy, X-ray photoelectron spectra, and element analysis were used to characterize and measure the samples. The as-prepared Cu 3 BiS 3 sample consisted of whisker-like particles with an average size of 50x10 nm 2 and the Pb 1-x Bi 2x/3 S sample displayed aggregative particles with size in the range of 30-50 nm. Preliminary results showed that the prepared precursors, reaction temperature and time played a role in the formation of the final products. A possible reaction mechanism was also discussed briefly

  10. Room temperature synthesis of crystalline Sb2S3 for SnO2 ...

    Indian Academy of Sciences (India)

    attention of researchers owing to their low cost, simple fabrication technique and .... The typical SEM images of as-deposited Sb2S3 in figure 3a show the .... reduce back the excited Sb2S3 to its ground state and to set the system for next ...

  11. A study of the Ne 2s2p{sup 5}({sup 3}P)3s and 3p correlation satellites up to 75 eV above threshold

    Energy Technology Data Exchange (ETDEWEB)

    Yarzhemsky, V G [RAS Kurnakov Institute of General and Inorganic Chemistry, Moscow (Russian Federation); Amusia, M Ya [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel); Bolognesi, P; Avaldi, L, E-mail: lorenzo.avaldi@imip.cnr.i [CNR-Istituto di Metodologie Inorganiche e dei Plasmi, Area della Ricerca di Roma 1, CP 10, 00016 Monterotondo Scalo (Italy)

    2010-09-28

    The 2s2p{sup 5}({sup 3}P)3s {sup 2}P, 3p {sup 2}D and {sup 2}S satellite states of neon have been studied at several energies from 5 to 75 eV above their respective thresholds. The relative intensities of the satellite states with respect to their main lines shed light on the nature of the many-electron correlations leading to the formation of these satellites. The experimental results are compared with a calculation which makes use of a random phase approximation with exchange (RPAE) cross sections, and takes into account the shake-up and direct knock-out channels as well as their interference.

  12. Synthesis, β-haematin inhibition, and in vitro antimalarial testing of isocryptolepine analogues: SAR study of indolo[3,2-c]quinolines with various substituents at C2, C6, and N11.

    Science.gov (United States)

    Wang, Ning; Wicht, Kathryn J; Imai, Kento; Wang, Ming-Qi; Anh Ngoc, Tran; Kiguchi, Ryo; Kaiser, Marcel; Egan, Timothy J; Inokuchi, Tsutomu

    2014-05-01

    A series of indolo[3,2-c]quinolines were synthesized by modifying the side chains of the ω-aminoalkylamines at the C6 position and introducing substituents at the C2 position, such as F, Cl, Br, Me, MeO and NO2, and a methyl group at the N11 position for an SAR study. The in vitro antiplasmodial activities of the derivative agents against two different strains (CQS: NF54 and CQR: K1) and the cytotoxic activity against normal L6 cells were evaluated. The test results showed that compounds 6k and 6l containing the branched methyl groups of 3-aminopropylamino at C6 with a Cl atom at C2 exhibited a very low cytotoxicity with IC50 values above 4000 nM, high antimalarial activities with IC50 values of about 11 nM for CQS (NF54), IC50 values of about 17 nM for CQR (K1), and RI resistance indices of 1.6. Furthermore, the compounds were tested for β-haematic inhibition, and QSAR revealed an interesting linear correlation between the biological activity of CQS (NF54) and three contributing factors, namely solubility, hydrophilic surface area, and β-haematin inhibition for this series. In vivo testing of 6l showed a reduction in parasitaemia on day 4 with an activity of 38%. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Disposable biosensor based on cathodic electrochemiluminescence of tris(2,2-bipyridine)ruthenium(II) for uric acid determination

    International Nuclear Information System (INIS)

    Ballesta-Claver, J.; Rodríguez-Gómez, R.; Capitán-Vallvey, L.F.

    2013-01-01

    Highlights: ► Cathodic ECL offers conventional and non-aggressive analysis conditions. ► The ECL hydrogen peroxide/ruthenium complex system for uric acid determination is novel. ► The ruthenium complex is electrochemically immobilized on graphite screen-printed electrodes. ► The quantification of the uric acid is based on a Stern–Volmer type equation. ► The use of the cathodic ECL working methodology reduces interferences during analysis. -- Abstract: A new method for uric acid (UA) determination based on the quenching of the cathodic ECL of the tris(2,2-bipyridine)ruthenium(II)–uricase system is described. The biosensor is based on a double-layer design containing first tris(2,2-bipyridine)ruthenium(II) (Ru(bpy) 3 2+ ) electrochemically immobilized on graphite screen-printed cells and uricase in chitosan as a second layer. The uric acid biosensing is based on the ECL quenching produced by uric acid over the cathodic ECL caused by immobilized Ru(bpy) 3 2+ in the presence of uricase. The use of a −1.1 V pulse for 1 s with a dwelling time of 10 s makes it possible to estimate the initial enzymatic rate, which is used as the analytical signal. The Stern–Volmer type calibration function shows a dynamic range from 1.0 × 10 −5 to 1.0 × 10 −3 M with a limit of detection of 3.1 × 10 −6 M and an accuracy of 13.6% (1.0 × 10 −4 M, n = 5) as relative standard deviation. Satisfactory results were obtained for urine samples, creating an affordable alternative for uric acid determination

  14. Thermoelectric properties of Bi2Te3 base solid solutions in the Bi2Te3-InS system

    International Nuclear Information System (INIS)

    Safarov, M.G.; Rustamov, P.G.; Alidzhanov, M.A.

    1979-01-01

    The rich Bi 2 Te 3 part ot the Bi 2 Te 3 -InS constitutional diagram has been studied with a view to produce new Bi 2 Te 3 -based solid solutions and to establish the maximum solubility of InS in Bi 2 Te 3 . The methods of differential-thermal, X-ray phase and microstructural analysis have been used. The alloys microhardness, density and thermal electric properties have been measured. A large region of Bi 2 Te 3 -based restricted solid solutions has been detected; it reaches 14.0 mol.% InS at room temperature. Studied have been the thermoelectromotive forces, electric and thermal conductivity of the alloys, containing up to 5 mol.% InS in the 300-700 K temperature range

  15. Study of the pseudo-ternary Ag2SAs2S3HgI2 vitreous system

    Science.gov (United States)

    Boidin, R.; Le Coq, D.; Cuisset, A.; Hindle, F.; Brubach, J.-B.; Michel, K.; Bychkov, E.

    2013-03-01

    Chalcogenide alloys in the Ag2SAs2S3HgI2 pseudo-ternary system were synthesized and their vitreous nature was verified by X-ray diffraction. The glass transition and crystallization temperatures (Tg and Tc), the density (d), and the total electrical conductivity (σ) were measured for all samples of three series, A, B, and C corresponding to (Ag2S)50-x/2(As2S3)50-x/2(HgI2)x, (Ag2S)y(As2S3)80-y(HgI2)20 and (Ag2S)z(As2S3)50(HgI2)50-z, respectively. The maximum of Tg was approximately 160 °C for glasses with low HgI2 content whereas the maximum of density (5.75 g cm-3) was obtained for the sample in the B-series with the highest Ag2S concentration (z=60 mol%). This composition also possesses the highest conductivity at 298 K (σ298 K≈10-3 S cm-1). Unexpectedly the conductivity of the A-series samples was observed to decrease as a function of the Ag2S content. The far-infrared transmission in the 100-600 cm-1 window range (3.3-18.2 THz, 100-16.6 μm) was also given for a few glass compositions highlighting the strong influence of the HgI2 content.

  16. Omega-3 polyunsaturated fatty acid has an anti-oxidant effect via the Nrf-2/HO-1 pathway in 3T3-L1 adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Kusunoki, Chisato, E-mail: yosizaki@belle.shiga-med.ac.jp [Department of Medicine, Shiga University of Medical Science, Seta Tsukinowa-Cho, Otsu, Shiga 520-2192 (Japan); Yang, Liu; Yoshizaki, Takeshi; Nakagawa, Fumiyuki; Ishikado, Atsushi; Kondo, Motoyuki; Morino, Katsutaro; Sekine, Osamu; Ugi, Satoshi [Department of Medicine, Shiga University of Medical Science, Seta Tsukinowa-Cho, Otsu, Shiga 520-2192 (Japan); Nishio, Yoshihiko [Division of Diabetes, Metabolism and Endocrinology, Department of Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8544 (Japan); Kashiwagi, Atsunori; Maegawa, Hiroshi [Department of Medicine, Shiga University of Medical Science, Seta Tsukinowa-Cho, Otsu, Shiga 520-2192 (Japan)

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer Omega-3 PUFA has a direct anti-oxidant effect in adipocytes. Black-Right-Pointing-Pointer EPA and DHA induce HO-1 expression in 3T3-L1 adipocytes. Black-Right-Pointing-Pointer Omega-3 PUFA and its end-product, 4-HHE, activates the Nrf-2/HO-1 pathway. Black-Right-Pointing-Pointer Omega-3 PUFA protects against oxidative stress-induced cytotoxicity. -- Abstract: Oxidative stress is produced in adipose tissue of obese subjects and has been associated with obesity-related disorders. Recent studies have shown that omega-3 polyunsaturated fatty acid ({omega}3-PUFA) has beneficial effects in preventing atherosclerotic diseases and insulin resistance in adipose tissue. However, the role of {omega}3-PUFA on adipocytes has not been elucidated. In this study, 3T3-L1 adipocytes were treated with {omega}3-PUFA and its metabolites, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), or 4-hydroxy hexenal (4-HHE). {omega}3-PUFA and its metabolites dose-dependently increased mRNA and protein levels of the anti-oxidative enzyme, heme oxygenase-1 (HO-1); whereas no changes in the well-known anti-oxidant molecules, superoxide dismutase, catalase, and glutathione peroxidase, were observed. Knockdown of nuclear factor erythroid 2-related factor 2 (Nrf-2) significantly reduced EPA, DHA or 4-HHE-induced HO-1 mRNA and protein expression. Also, pretreatment with {omega}3-PUFA prevented H{sub 2}O{sub 2}-induced cytotoxicity in a HO-1 dependent manner. In conclusion, treatment with EPA and DHA induced HO-1 through the activation of Nrf-2 and prevented oxidative stress in 3T3-L1 adipocytes. This anti-oxidant defense may be of high therapeutic value for clinical conditions associated with systemic oxidative stress.

  17. The borosulfates K{sub 4}[BS{sub 4}O{sub 15}(OH)], Ba[B{sub 2}S{sub 3}O{sub 13}], and Gd{sub 2}[B{sub 2}S{sub 6}O{sub 24}

    Energy Technology Data Exchange (ETDEWEB)

    Gross, Peter; Kirchhain, Arno; Hoeppe, Henning A. [Universitaet Augsburg, Institut fuer Physik (Germany)

    2016-03-18

    K{sub 4}[BS{sub 4}O{sub 15}(OH)], Ba[B{sub 2}S{sub 3}O{sub 13}], and Gd{sub 2}[B{sub 2}S{sub 6}O{sub 24}] were obtained by a new synthetic approach. The strategy involves initially synthesizing the complex acid H[B(HSO{sub 4}){sub 4}] which is subsequently reacted in an open system with anhydrous chlorides of K, Ba, and Gd to the respective borosulfates and a volatile molecule (HCl). Furthermore, protonated borosulfates should be accessible by appropriate stoichiometry of the starting materials, particularly in closed systems, which inhibit deprotonation of H[B(HSO{sub 4}){sub 4}] via condensation and dehydration. This approach led to the successful synthesis of the first divalent and trivalent metal borosulfates (Ba[B{sub 2}S{sub 3}O{sub 13}] with band-silicate topology and Gd{sub 2}[B{sub 2}S{sub 6}O{sub 24}] with cyclosilicate topology) and the first hydrogen borosulfate K{sub 4}[BS{sub 4}O{sub 15}(OH)]. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Korean Red Ginseng Extract Attenuates 3-Nitropropionic Acid-Induced Huntington’s-Like Symptoms

    Directory of Open Access Journals (Sweden)

    Minhee Jang

    2013-01-01

    Full Text Available Korean red ginseng (KRG possesses neuroprotective activity. However, the potential neuroprotective value of KRG for the striatal toxicity is largely unknown. We investigated whether KRG extract (KRGE could have a neuroprotective effect in a 3-nitropropionic acid- (3-NP induced (i.p. Huntington’s disease (HD model. KRGE (50, 100, and 250 mg/kg/day, p.o. was administrated 10 days before 3-NP injection (pre-administration, from the same time with 3-NP injection (co-administration, or from the peak point of neurological impairment by 3-NP injection (post-administration. Pre-administration of KRGE produced the greatest neuroprotective effect in this model. Pre-administration of KRGE significantly decreased 3-NP-induced neurological impairment, lethality, lesion area, and neuronal loss in the 3-NP-injected striatum. KRGE attenuated microglial activation and phosphorylation of mitogen-activated protein kinases (MAPKs and nuclear factor-kappa B (NF-κB signal pathway. KRGE also reduced the level of mRNA expression of tumor necrosis factor-alpha, interleukin- (IL- 1β, IL-6, inducible nitric oxide synthase, and OX-42. Interestingly, the intrathecal administration of SB203580 (a p38 inhibitor or PD98059 (an inhibitor of MAPK Kinase, MEK increased the survival rate in the 3-NP-induced HD model. Pre-administration of KRGE may effectively inhibit 3-NP-induced striatal toxicity via the inhibition of the phosphorylation of MAPKs and NF-κB pathways, indicating its therapeutic potential for suppressing Huntington’s-like symptoms.

  19. Benthic fauna of extremely acidic lakes (pH 2-3)

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, G G

    2001-07-01

    The structure of the benthic invertebrate communities were investigated in terms of composition, abundance, and biomass from extremely acidic lakes with pH values from 2 to 3 in areas where coal was intensively mined in the Lusatian region in the eastern region of Germany. Benthic invertebrates colonisation on leaves and the breakdown rate processing of the three deciduous leaf: Betula pendula (birch), Fraxinus excelsior (ash), and Juglans regia (walnut) were investigated. Also, the main key-species of these acidic environments were investigated, in terms of description of pupal exuviae of Chironomus crassimanus and the feeding habit of this acid-resistant species through analysis of their gut content. The benthic food web in extremely acidic mining Lusatian lakes is very short in terms of species richness, trophic relationship, guilds and functional feeding groups. Collector-filters and scraper-grazers were absent in extremely acidic mining lakes (AML 107, AML 111 and AML 117). Shredders as Limnophyes minimus (Diptera, Chironomidae, Orthocladiinae) and Hydrozetes lacustris (Acari, Hydrozetidae) occurred in low abundance in AML 107 and AML 111, and it may be in response to slow leaf breakdown process in these ecosystems, except in AML 117 where the H. lacustris contributed most to ecosystems functioning via the processing of litter. Aquatic insects as Sialis lutaria (Megaloptera, Sialidae), Orectochilus villosus (Coleoptera, Gyrinidae), Coenagrion mercuriale (Odonata, Coenagrionidae), and Phryganeidae (Trichoptera) are the top-predators of these ecosystems. They did not depend on the level of pH in the lakes, but on the availability of food resources. (orig.)

  20. Molecular Characterization of the Llamas (Lama glama) Casein Cluster Genes Transcripts (CSN1S1, CSN2, CSN1S2, CSN3) and Regulatory Regions

    Science.gov (United States)

    Pauciullo, Alfredo; Erhardt, Georg

    2015-01-01

    In the present paper, we report for the first time the characterization of llama (Lama glama) caseins at transcriptomic and genetic level. A total of 288 casein clones transcripts were analysed from two lactating llamas. The most represented mRNA populations were those correctly assembled (85.07%) and they encoded for mature proteins of 215, 217, 187 and 162 amino acids respectively for the CSN1S1, CSN2, CSN1S2 and CSN3 genes. The exonic subdivision evidenced a structure made of 21, 9, 17 and 6 exons for the αs1-, β-, αs2- and κ-casein genes respectively. Exon skipping and duplication events were evidenced. Two variants A and B were identified in the αs1-casein gene as result of the alternative out-splicing of the exon 18. An additional exon coding for a novel esapeptide was found to be cryptic in the κ-casein gene, whereas one extra exon was found in the αs2-casein gene by the comparison with the Camelus dromedaries sequence. A total of 28 putative phosphorylated motifs highlighted a complex heterogeneity and a potential variable degree of post-translational modifications. Ninety-six polymorphic sites were found through the comparison of the lama casein cDNAs with the homologous camel sequences, whereas the first description and characterization of the 5’- and 3’-regulatory regions allowed to identify the main putative consensus sequences involved in the casein genes expression, thus opening the way to new investigations -so far- never achieved in this species. PMID:25923814

  1. Molecular Characterization of the Llamas (Lama glama) Casein Cluster Genes Transcripts (CSN1S1, CSN2, CSN1S2, CSN3) and Regulatory Regions.

    Science.gov (United States)

    Pauciullo, Alfredo; Erhardt, Georg

    2015-01-01

    In the present paper, we report for the first time the characterization of llama (Lama glama) caseins at transcriptomic and genetic level. A total of 288 casein clones transcripts were analysed from two lactating llamas. The most represented mRNA populations were those correctly assembled (85.07%) and they encoded for mature proteins of 215, 217, 187 and 162 amino acids respectively for the CSN1S1, CSN2, CSN1S2 and CSN3 genes. The exonic subdivision evidenced a structure made of 21, 9, 17 and 6 exons for the αs1-, β-, αs2- and κ-casein genes respectively. Exon skipping and duplication events were evidenced. Two variants A and B were identified in the αs1-casein gene as result of the alternative out-splicing of the exon 18. An additional exon coding for a novel esapeptide was found to be cryptic in the κ-casein gene, whereas one extra exon was found in the αs2-casein gene by the comparison with the Camelus dromedaries sequence. A total of 28 putative phosphorylated motifs highlighted a complex heterogeneity and a potential variable degree of post-translational modifications. Ninety-six polymorphic sites were found through the comparison of the lama casein cDNAs with the homologous camel sequences, whereas the first description and characterization of the 5'- and 3'-regulatory regions allowed to identify the main putative consensus sequences involved in the casein genes expression, thus opening the way to new investigations -so far- never achieved in this species.

  2. [3H]-labelling of hydroxyethyl groups - synthesis of S-(2-hydroxy [2-3H] ethyl) glutathione and of [3H]-melphalan

    International Nuclear Information System (INIS)

    Verny, M.; Nicolas, C.

    1988-01-01

    The easy preparation of 2-bromo [1- 3 H] ethanol allows the tritium labelling of molecules bearing S- or N-hydroxyethyl groups. Thus S-(2-hydroxy [2- 3 H] ethyl) glutathione and [ 3 H]-Melphalan were synthesised with specific radioactivities of around 10 mCi/mmol (370 MBq/mmol). These values could be theoretically raised to 10 Ci/mmol (370 GBq/mmol), according to the specific activity of the labelling precursor, sodium [ 3 H] borohydride. (author)

  3. Acid indium strontium phosphate SrIn2[PO3(OH)]4: synthesis and crystal structure

    International Nuclear Information System (INIS)

    Rusakov, D.A.; Bobylev, A.P.; Komissarova, L.N.; Filaretov, A.A.; Danilov, V.P.

    2007-01-01

    Acid indium-strontium phosphate SrIn 2 [PO 3 (OH)] 4 is synthesized and characterized. Crystal structure and lattice parameters ate determined. In atoms in SrIn 2 [PO 3 (OH)] 4 structure are in distorted InO 6 octahedrons and form with PO 3 (OH) tetrahedrons mixed paraskeleton {In 2 [PO 3 (OH)] 4 } 32- with emptinesses occupied by big Sr 2+ cations. The compound is thermally stable up to 400 Deg C [ru

  4. 7-{[2-(4-Hydroxyphenylmethylidene]amino}-1,3-thiazol-4-yl-2-(methoxyiminoacetyl]amino}-3-{[(2-methyl-5,6-dioxo-1,2,5,6-tetrahydro-1,2,4-triazin-3-ylsulfanyl]methyl}-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic Acid

    Directory of Open Access Journals (Sweden)

    Ghulam Fareed

    2012-05-01

    Full Text Available Novel 7-{[2-(4-hydroxyphenylmethylidene]amino}-1,3-thiazol-4-yl-2-(methoxyiminoacetyl]amino}-3-{[(2-methyl-5,6-dioxo-1,2,5,6-tetrahydro-1,2,4-triazin-3-ylsulfanyl]methyl}-8-oxo-5-thia-1azabicyclo [4.2.0]oct-2-ene-2-carboxylic acid was prepared by condensation of ceftriaxone disodium (1 with 4-hydroxybenzaldehyde (2 in ethanol under reflux conditions for 3–4 h. The structure of synthesized compound was elucidated using LCMS, 1H-NMR, and CHN techniques.

  5. Resolution of 1-n-butyl-3-methyl-3-phospholene 1-oxide with TADDOL derivatives and calcium salts of O,O'-Dibenzoyl-(2R,3R)- or O,O'-di-p-toluoyl-(2R,3R)-tartaric acid.

    Science.gov (United States)

    Bagi, Péter; Fekete, András; Kállay, Mihály; Hessz, Dóra; Kubinyi, Miklós; Holczbauer, Tamás; Czugler, Mátyás; Fogassy, Elemér; Keglevich, György

    2014-03-01

    The resolution methods applying (-)-(4R,5R)-4,5-bis(diphenylhydroxymethyl)-2,2-dimethyldioxolane ("TADDOL"), (-)-(2R,3R)-α,α,α',α'-tetraphenyl-1,4-dioxaspiro[4.5]decan-2,3-dimethanol ("spiro-TADDOL"), as well as the acidic and neutral Ca(2+) salts of (-)-O,O'-dibenzoyl- and (-)-O,O'-di-p-toluoyl-(2R,3R)-tartaric acid were extended for the preparation of 1-n-butyl-3-methyl-3-phospholene 1-oxide in optically active form. In one case, the intermediate diastereomeric complex could be identified by single-crystal X-ray analysis. The absolute P-configuration of the enantiomers of the phospholene oxide was also determined by comparing the experimentally obtained and calculated CD spectra. © 2014 Wiley Periodicals, Inc.

  6. Cisplatin neuropathy. Risk factors, prognosis, and protection by WR-2721

    International Nuclear Information System (INIS)

    Mollman, J.E.; Glover, D.J.; Hogan, W.M.; Furman, R.E.

    1988-01-01

    A prospective study of patients receiving cis-diaminedichloroplatin II (DDP) was carried out to determine if risk factors could be identified related to the patient's living habits or past medical history that would predict in which patients DDP neuropathy might develop. Sixty-nine patients receiving six different combinations of chemotherapeutic agents, including DDP were examined. Twenty-eight of these patients received DDP in combination with the radioprotective agent S-2-(3-aminopropylamino)-ethylphosporothioic acid (WR 2721). No risk factors were identified relating to personal habits or past medical history of the patients. However, patients receiving DDP (40 mg/m2) on 5 consecutive days had a significantly higher incidence of neuropathy. Patients receiving DDP in combination with WR 2721 had a significantly lower incidence of neuropathy, and the mean dose at onset was significantly higher than the mean dose at onset of neuropathy for all other groups. In addition, five of six patients who were available for long-term follow-up demonstrated nearly complete reversal of the signs and symptoms of neuropathy

  7. Lewis acid catalyzed [3 + 2] annulation of ketenimines with donor-acceptor cyclopropanes: an approach to 2-alkylidenepyrrolidine derivatives.

    Science.gov (United States)

    Alajarin, Mateo; Egea, Adrian; Orenes, Raul-Angel; Vidal, Angel

    2016-11-02

    The [3 + 2] annulation reaction of C,C,N-trisubstituted ketenimines with donor-acceptor cyclopropanes bearing aryl, styryl and vinyl substituents at the C2 position, triggered by the Lewis acid Sc(OTf) 3 , supplies highly substituted pyrrolidines. Activated cyclopropanes fused to naphthalene and [1]benzopyrane nuclei are also suitable substrates in similar transformations, yielding partially saturated benz[g]indoles and [1]benzopyran[4,3-b]pyrroles. An intramolecular version of this ketenimine/cyclopropane [3 + 2] annulation has also been developed leading to the pyrrolo[2,1-a]isoindole framework.

  8. Synthesis and physical-chemical properties of 2-((4-R-3-(morpholinomethylen-4H-1,2,4-triazole-5ylthioacetic acid

    Directory of Open Access Journals (Sweden)

    R. О. Shcherbyna

    2014-12-01

    Full Text Available The creation and improvement of the original domestic medicines is anactual problem of medical and pharmaceutical industries. Chemistry of heterocyclicsystems attracts scientists all over the world, as it is associated with a number of properties of this class of compounds which allow to use them for various purposes. It is known that the morpholine salts of 2-((4-R-5-R1-4H-1,2,4-triazoles-3-ylthioacetic acids exhibit low toxicity and pronounced pharmacological effect. The additional morpholine moiety in the 1,2,4-triazole’s nucleusshould lead to compounds with high biological activity. The aim of researchis the synthesis of 2-((4-R-3-(morpholinomethylen-4H-1,2,4-triazole-5-ylthioaceticacidsand determination of its physical-chemical properties. Materials and methods.The determinationof physical-chemical propertiesof the obtained compounds has been carried out according to the methods listed in the State Pharmacopoeia of Ukraine. The determinationof melting temperature has been performed for the synthesized compounds (device OptiMelt Stanford Research Systems MPA100. The structure of the compoundshas been confirmed by 1H NMR spectroscopy (Mercury 400, chromatography-mass spectrometry (Agilent 1260 Infinity device with mass detector Agilent 6120 LC / MS and elemental analysis (ElementarVario L cube. Results.14 new synthesized compounds, namely isopropyl 2-morpholinoacetate, 2-morpholinoacetohydrazide, N-R-2-(2-morpholinoacetylhydrazinecarbothioamides, 2-(2-morpholinoacetyl-hydrazinecarbothioamide, 3-(morpholinomethyl-4-R-4H-1,2,4-triazole-5-thiolesand2-((4-R-3-(morpholinomethylen-4H-1,2,4-triazole-5-ylthioaceticacid(where, R=H, CH3, C2H5,C6H5 have been studied.The fragmentation of 2-((4-ethyl-3-(morpholinomethyl-4H-1,2,4-triazol-5-ylthioacetic acid has been carried out usingmethod of LC/MS and fragment ions have been identified. The structure of the synthesized compounds in all cases has been confirmed by modern instrumental methods of analysis

  9. Acid-base properties of the surface of the α-Al2O3 suspension

    Science.gov (United States)

    Ryazanov, M. A.; Dudkin, B. N.

    2009-12-01

    The distribution of the acid-base centers on the surface of α-Al2O3 suspension particles was studied by potentiometric titration, and the corresponding p K spectra were constructed. It was inferred that the double electric layer created by the supporting electrolyte substantially affected the screening of the acid-base centers on the particle surface of the suspension.

  10. Advanced asymmetric synthesis of (1R,2S)-1-amino-2-vinylcyclopropanecarboxylic acid by alkylation/cyclization of newly designed axially chiral Ni(II) complex of glycine Schiff base.

    Science.gov (United States)

    Kawashima, Aki; Shu, Shuangjie; Takeda, Ryosuke; Kawamura, Akie; Sato, Tatsunori; Moriwaki, Hiroki; Wang, Jiang; Izawa, Kunisuke; Aceña, José Luis; Soloshonok, Vadim A; Liu, Hong

    2016-04-01

    Asymmetric synthesis of (1R,2S)-1-amino-2-vinylcyclopropanecarboxylic acid (vinyl-ACCA) is in extremely high demand due to the pharmaceutical importance of this tailor-made, sterically constrained α-amino acid. Here we report the development of an advanced procedure for preparation of the target amino acid via two-step SN2 and SN2' alkylation of novel axially chiral nucleophilic glycine equivalent. Excellent yields and diastereoselectivity coupled with reliable and easy scalability render this method of immediate use for practical synthesis of (1R,2S)-vinyl-ACCA.

  11. Topological surface Fermi arcs in magnetic Weyl semimetal Co$_3$Sn$_2$S$_2$

    OpenAIRE

    Xu, Qiunan; Liu, Enke; Shi, Wujun; Muechler, Lukas; Felser, Claudia; Sun, Yan

    2017-01-01

    Very recently, the half-metallic compound Co$_3$Sn$_2$S$_2$ was predicted to be a magnetic WSM with Weyl points only 60 meV above the Fermi level ($E_F$). Owing to the low charge carrier density and large Berry curvature induced, Co$_3$Sn$_2$S$_2$ possesses both a large anomalous Hall conductivity (AHC) and a large anomalous Hall angle (AHA), which provide strong evidence for the existence of Weyl points in Co$_3$Sn$_2$S$_2$. In this work, we theoretically studied the surface topological feat...

  12. Secreted Frizzled-related protein-2 (sFRP2) augments canonical Wnt3a-induced signaling

    Energy Technology Data Exchange (ETDEWEB)

    Marschall, Zofia von [Craniofacial and Skeletal Diseases Branch, NIDCR, NIH, DHHS, Bethesda, MD (United States); Fisher, Larry W., E-mail: lfisher@dir.nidcr.nih.gov [Craniofacial and Skeletal Diseases Branch, NIDCR, NIH, DHHS, Bethesda, MD (United States)

    2010-09-24

    Research highlights: {yields} sFRP2 enhances the Wnt3a-induced {beta}-catenin stabilization and its nuclear translocation. {yields} sFRP2 enhances LRP6 phosphorylation and Wnt3a/{beta}-catenin transcriptional reporter activity. {yields} Dickkopf-1 (DKK1) fully antagonizes both Wnt3a/sFRP2-induced LRP6 phosphorylation and transcriptional activity. {yields} sFRP2 enhances expression of genes known to be regulated by Wnt3a signaling. -- Abstract: Secreted Frizzled-related proteins (sFRP) are involved in embryonic development as well as pathological conditions including bone and myocardial disorders and cancer. Because of their sequence homology with the Wnt-binding domain of Frizzled, they have generally been considered antagonists of canonical Wnt signaling. However, additional activities of various sFRPs including both synergism and mimicry of Wnt signaling as well as functions other than modulation of Wnt signaling have been reported. Using human embryonic kidney cells (HEK293A), we found that sFRP2 enhanced Wnt3a-dependent phosphorylation of LRP6 as well as both cytosolic {beta}-catenin levels and its nuclear translocation. While addition of recombinant sFRP2 had no activity by itself, Top/Fop luciferase reporter assays showed a dose-dependent increase of Wnt3a-mediated transcriptional activity. sFRP2 enhancement of Wnt3a signaling was abolished by treatment with the Wnt antagonist, Dickkopf-1 (DKK1). Wnt-signaling pathway qPCR arrays showed that sFRP2 enhanced the Wnt3a-mediated transcriptional up-regulation of several genes regulated by Wnt3a including its antagonists, DKK1, and Naked cuticle-1 homolog (NKD1). These results support sFRP2's role as an enhancer of Wnt/{beta}-catenin signaling, a result with biological impact for both normal development and diverse pathologies such as tumorigenesis.

  13. Secreted Frizzled-related protein-2 (sFRP2) augments canonical Wnt3a-induced signaling

    International Nuclear Information System (INIS)

    Marschall, Zofia von; Fisher, Larry W.

    2010-01-01

    Research highlights: → sFRP2 enhances the Wnt3a-induced β-catenin stabilization and its nuclear translocation. → sFRP2 enhances LRP6 phosphorylation and Wnt3a/β-catenin transcriptional reporter activity. → Dickkopf-1 (DKK1) fully antagonizes both Wnt3a/sFRP2-induced LRP6 phosphorylation and transcriptional activity. → sFRP2 enhances expression of genes known to be regulated by Wnt3a signaling. -- Abstract: Secreted Frizzled-related proteins (sFRP) are involved in embryonic development as well as pathological conditions including bone and myocardial disorders and cancer. Because of their sequence homology with the Wnt-binding domain of Frizzled, they have generally been considered antagonists of canonical Wnt signaling. However, additional activities of various sFRPs including both synergism and mimicry of Wnt signaling as well as functions other than modulation of Wnt signaling have been reported. Using human embryonic kidney cells (HEK293A), we found that sFRP2 enhanced Wnt3a-dependent phosphorylation of LRP6 as well as both cytosolic β-catenin levels and its nuclear translocation. While addition of recombinant sFRP2 had no activity by itself, Top/Fop luciferase reporter assays showed a dose-dependent increase of Wnt3a-mediated transcriptional activity. sFRP2 enhancement of Wnt3a signaling was abolished by treatment with the Wnt antagonist, Dickkopf-1 (DKK1). Wnt-signaling pathway qPCR arrays showed that sFRP2 enhanced the Wnt3a-mediated transcriptional up-regulation of several genes regulated by Wnt3a including its antagonists, DKK1, and Naked cuticle-1 homolog (NKD1). These results support sFRP2's role as an enhancer of Wnt/β-catenin signaling, a result with biological impact for both normal development and diverse pathologies such as tumorigenesis.

  14. Production of 3-Oxo-2-(2'-pentenyl)-cyclopentane-1-octanoic Acid in the Fungus Aspergillus oryzae: A Step Towards Heterologous Production of Pyrethrins in Fungi.

    Science.gov (United States)

    Mohamed, Maged E; Pahirulzaman, Khomaizon A K; Lazarus, Colin M

    2016-03-01

    Pyrethrins are natural insecticides, which accumulate to high concentrations in pyrethrum (Chrysanthemum cinerariaefolium) flowers. Synthetic pyrethroids are more stable, more efficacious and cheaper, but contemporary requirements for safe and environmentally friendly pesticides encourage a return to the use of natural pyrethrins, and this would be favoured by development of an efficient route to their production by microbial fermentation. The biosynthesis of pyrethrins involves ester linkage between an acid moiety (chrysanthemoyl or pyrethroyl, synthesised via the mevalonic acid pathway from glucose), and an alcohol (pyrethrolone). Pyrethrolone is generated from 3-oxo-2-(2'-pentenyl)-cyclopentane-1-octanoic acid, which originates from α-linolenic acid via the jasmonic acid biosynthetic cascade. The first four genes in this cascade, encoding lipoxygenase 2, allene-oxide synthase, allene-oxide cyclase 2 and 12-oxophytodienoic acid reductase 3, were amplified from an Arabidopsis thaliana cDNA library, cloned in a purpose-built fungal multigene expression vector and expressed in Aspergillus oryzae. HPLC-MS analysis of the transgenic fungus homogenate gave good evidence for the presence of 3-oxo-2-(2'-pentenyl)-cyclopentane-1-octanoic acid.

  15. Molecular pharmacology of 4-substituted glutamic acid analogues at ionotropic and metabotropic excitatory amino acid receptors

    DEFF Research Database (Denmark)

    Bräuner-Osborne, Hans; Nielsen, B; Stensbøl, T B

    1997-01-01

    (subtypes 1alpha and 2), respectively, whereas (S)-4-methyleneglutamic acid showed high but rather non-selective affinity for the (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA), kainic acid, NMDA and mGlu receptors (subtypes 1alpha and 2). Although none of the compounds were specific......The pharmacology of (2S,4R)-4-methylglutamic acid, (2S,4S)-4-methylglutamic acid and (S)- and (R)-4-methyleneglutamic acids (obtained in high chemical and enantiomeric purity from racemic 4-methyleneglutamic acid by chiral HPLC using a Crownpak CR(+) column), was examined in binding experiments...... using rat brain ionotropic glutamate receptors, and in functional assays using cloned metabotropic glutamate (mGlu) receptors. As a notable result of these studies, (2S,4R)-4-methylglutamic acid and (2S,4S)-4-methylglutamic acid were shown to be selective for kainic acid receptors and mGlu receptors...

  16. PROPERTIES OF NEW SALTS OF 2-(5-(ADAMANTANE-1-YL-4-R-1,2,4-TRIAZOLE-3-YLTIOACETIC ACIDS IN THE GLUCOSE TOLERANCE TEST

    Directory of Open Access Journals (Sweden)

    V. M. Odyntsova

    2015-04-01

    Full Text Available The concentration of glucose in the blood is one of the integral indicators of the internal environment that reflects the metabolism of carbohydrates, proteins and fats in the body. Glucose is a key component of human metabolism. The level of blood sugar is one of the most important controlled constants of body that defines homeostasis and displays the status of carbohydrate metabolism. Low blood sugar (hypoglycemia is a dangerous condition when blood glucose is critically low. The aim of research. The aim of our study was pharmacological screening of the effects of the newly synthesized salts of 2-(5-adamantane-1-yl-4-R-1,2,4-tirazol-3-yltioacetic acids on glucose blood level in experimental animals. Materials and methods. The compounds have been synthesized at the Department of Inorganic Chemistry and Toxicology of Zaporozhye State Medical University (the Head of the chair, Professor Panasenko O.I.. Blood glucose levels of saults of2-(5-adamantane-1-yl-4-R-1,2,4-tirazol-3-yltioacetic acids in rats have been evaluated by intraperitoneal glucose tolerance test (IGTT. IGTT was reproduced by glucose load on animals in a dose of 2 g / kg of rat’s body weight. White nonlinear rats weighing 160-230 g were involved in experiments. Animals were divided into 13 groups of 7 animals in each group: the 1st is intact one; the 2nd is control one with glycemia (untreated, the 3rd group of the animals received glibenclamide in the dose of 1 mg / kg; the groups 3-13 received 1,2,4-triazole derivatives. The compounds were dissolved in purified water at the rate of 1 ml per 100 g of animals’ weight and were injected intraperitoneally. Glucose content in blood has been measured by glucosidase method using glucometer «Accu Chek Active» in 30 minutes from the load moment. The research results have been processed by modern statistical methods of analysis on a personal computer using a standard software package Microsoft Office 2010 (Microsoft Excel and

  17. AdS3 xw (S3 x S3 x S1) solutions of type IIB string theory

    International Nuclear Information System (INIS)

    Donos, Aristomenis; Gauntlett, Jerome P.; Imperial College, London; Sparks, James

    2008-10-01

    We analyse a recently constructed class of local solutions of type IIB supergravity that consist of a warped product of AdS 3 with a sevendimensional internal space. In one duality frame the only other nonvanishing fields are the NS three-form and the dilaton. We analyse in detail how these local solutions can be extended to globally well-defined solutions of type IIB string theory, with the internal space having topology S 3 x S 3 x S 1 and with properly quantised three-form flux. We show that many of the dual (0,2) SCFTs are exactly marginal deformations of the (0,2) SCFTs whose holographic duals are warped products of AdS 3 with seven-dimensional manifolds of topology S 3 x S 2 x T 2 . (orig.)

  18. One-pot syntheses of Li3V2(PO4)3/C cathode material for lithium ion batteries via ascorbic acid reduction approach

    International Nuclear Information System (INIS)

    Huang, J.S.; Yang, L.; Liu, K.Y.

    2011-01-01

    Highlights: → Ascorbic acid (C 6 H 8 O 6 ) was used as reducing agent and organic carbon source. → The strategy shortened the period of material preparation and lowered energy cost. → Li 3 V 2 (PO 4 ) 3 /C was obtained with enhanced electrochemical performance. → Effects of reagents on electrochemical performance of Li 3 V 2 (PO 4 ) 3 were evaluated. - Abstract: Monoclinic Li 3 V 2 (PO 4 ) 3 /C composite synthesized by ascorbic acid reduction method is examined as a cathode material for Li-ion batteries. Transmission electron microscopy (TEM) images show that the nano-size particles are obtained. The reversible capacity of Li 3 V 2 (PO 4 ) 3 /C prepared with LiOH and H 3 PO 4 is 141.2 mAh g -1 after 100 cycles at 1C discharge rate between 3 V and 4.8 V, and the retention rates of discharge capacity is 93.4%. Ascorbic acid plays not only as reduction reagent, but also as carbon sources. This strategy shortens the time of solid state reaction and facilitates the procedure of synthesis. Effects of different precursors materials on the performance of the Li 3 V 2 (PO 4 ) 3 /C are investigated.

  19. Photoacoustic spectroscopy of thin films of As2S3, As2Se3 and GeSe2

    Indian Academy of Sciences (India)

    Photoacoustic spectroscopy (PAS) is one of the important branches of spectroscopy, which enables one to detect light-induced heat production following the absorption of pulsed radiation by the sample. As2S3, As2Se3 and GeSe2 exhibit a wide variety of photo-induced phenomena that enable them to be used as optical ...

  20. H2S-induced HCO3- secretion in the rat stomach--involvement of nitric oxide, prostaglandins, and capsaicin-sensitive sensory neurons.

    Science.gov (United States)

    Takeuchi, Koji; Ise, Fumitaka; Takahashi, Kento; Aihara, Eitaro; Hayashi, Shusaku

    2015-04-30

    Hydrogen sulfide (H2S) is known to be an important gaseous mediator that affects various functions under physiological and pathological conditions. We examined the effects of NaHS, a H2S donor, on HCO3(-) secretion in rat stomachs and investigated the mechanism involved in this response. Under urethane anesthesia, rat stomachs were mounted on an ex vivo chamber and perfused with saline. Acid secretion had been inhibited by omeprazole. The secretion of HCO3(-) was measured at pH 7.0 using a pH-stat method and by the addition of 10 mM HCl. NaHS (0.5-10 mM) was perfused in the stomach for 5 min. Indomethacin or L-NAME was administered s.c. before NaHS treatment, while glibenclamide (a KATP channel blocker), ONO-8711 (an EP1 antagonist), or propargylglycine (a cystathionine γ-lyase inhibitor) was given i.p. before. The mucosal perfusion of NaHS dose-dependently increased the secretion of HCO3(-), and this effect was significantly attenuated by indomethacin, L-NAME, and sensory deafferentation, but not by glibenclamide or ONO-8711. The luminal output of nitric oxide, but not the mucosal production of prostaglandin E2, was increased by the perfusion of NaHS. Mucosal acidification stimulated HCO3(-) secretion, and this response was inhibited by sensory deafferentation, indomethacin, L-NAME, and ONO-8711, but not by propargylglycine. These results suggested that H2S increased HCO3(-) secretion in the stomach, and this effect was mediated by capsaicin-sensitive afferent neurons and dependent on nitric oxide and prostaglandins, but not ATP-sensitive K(+) channels. Further study is needed to define the role of endogenous H2S in the mechanism underlying acid-induced gastric HCO3(-) secretion. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Chemo-Enzymatic Synthesis of Chiral Epoxides Ethyl and Methyl (S-3-(Oxiran-2-ylpropanoates from Renewable Levoglucosenone: An Access to Enantiopure (S-Dairy Lactone

    Directory of Open Access Journals (Sweden)

    Aurélien A. M. Peru

    2016-07-01

    Full Text Available Chiral epoxides—such as ethyl and methyl (S-3-(oxiran-2-ylpropanoates ((S-1a/1b—are valuable precursors in many chemical syntheses. Until recently, these compounds were synthesized from glutamic acid in four steps (deamination, reduction, tosylation and epoxide formation in low to moderate overall yield (20%–50%. Moreover, this procedure requires some harmful reagents such as sodium nitrite ((ecotoxic and borane (carcinogen. Herein, starting from levoglucosenone (LGO, a biobased chiral compound obtained through the flash pyrolysis of acidified cellulose, we propose a safer and more sustainable chemo-enzymatic synthetic pathway involving lipase-mediated Baeyer-Villiger oxidation, palladium-catalyzed hydrogenation, tosylation and treatment with sodium ethoxide/methoxide as key steps. This route afforded ethyl and methyl (S-3-(oxiran-2-ylpropanoates in 57% overall yield, respectively. To demonstrate the potentiality of this new synthetic pathway from LGO, the synthesis of high value-added (S-dairy lactone was undertaken from these epoxides and provided the target in 37% overall yield from LGO.

  2. l-2-Nitrimino-1,3-diazepane-4-carboxylic acid

    Directory of Open Access Journals (Sweden)

    Harutyun A. Karapetyan

    2008-05-01

    Full Text Available The cyclic form of l-nitroarginine, C6H10N4O4, crystallizes with two independent molecules in the asymmetric unit. According to the geometrical parameters, similar in both molecules, the structure corresponds to that of l-2-nitrimino-1,3-diazepane-4-carboxylic acid; there are, however, conformational differences between the independent molecules, one of them being close to a twisted chair while the other might be described as a rather flattened boat. All six active H atoms in the two molecules are involved in hydrogen bonds, two of which are intramolecular and four intermolecular, forming an infinite chain of molecules along the b axis.

  3. Measurement of the spin-forbidden decay rate (3s3d)1D2¿(3s3p)3 P2,1 in 24Mg

    DEFF Research Database (Denmark)

    Therkildsen, K. T.; Jensen, Brian Bak; Ryder, C. P.

    2009-01-01

    We have measured the spin-forbidden decay rate from (3s3d)D12¿(3s3p)P32,1 in M24g atoms trapped in a magneto-optical trap. The total decay rate, summing up both exit channels (3s3p)P31 and (3s3p)P32 , yields 196±10s-1 in excellent agreement with resent relativistic many-body calculations of Porse...

  4. High efficient conversion of furfural to 2-methylfuran over Ni-Cu/Al2O3 catalyst with formic acid as a hydrogen donor

    DEFF Research Database (Denmark)

    Fu, Zhaolin; Wang, Ze; Lin, Weigang

    2017-01-01

    Conversion of furfural to 2-methylfuran over Cu/Al2O3, Ni/Al2O3 and Ni-Cu/Al2O3 catalysts were investigated with formic acid as a hydrogen donor. Ni/Al2O3 showed a high catalytic activity but a moderate selectivity to 2-methylfuran. Contrarily, Cu/Al2O3 showed a low catalytic activity but a high...... selectivity for carbonyl reduction. Over the bimetallic catalysts Ni-10%Cu/Al2O3, by increasing Ni content, more furfural was converted with the reduction of carbonyl primarily. The effect of reaction solvent and the fraction of formic acid were also studied. The result showed that isopropanol solvent could...

  5. Electronic and structural properties of B i2S e3:Cu

    Science.gov (United States)

    Sobczak, Kamil; Strak, Pawel; Kempisty, Pawel; Wolos, Agnieszka; Hruban, Andrzej; Materna, Andrzej; Borysiuk, Jolanta

    2018-04-01

    Electronic and structural properties of B i2S e3 and its extension to copper doped B i2S e3:Cu were studied using combined ab initio simulations and transmission electron microscopy based techniques, including electron energy loss spectroscopy, energy filtered transmission electron microscopy, and energy dispersive x-ray spectroscopy. The stability of the mixed phases was investigated for substitutional and intercalation changes of basic B i2S e3 structure. Four systems were compared: B i2S e3 , structures obtaining by Cu intercalation of the van der Waals gap, by substitution of Bi by Cu in quintuple layers, and C u2Se . The structures were identified and their electronic properties were obtained. Transmission electron microscopy measurements of B i2S e3 and the B i2S e3:Cu system identified the first structure as uniform and the second as composite, consisting of a nonuniform lower-Cu-content matrix and randomly distributed high-Cu-concentration precipitates. Critical comparison of the ab initio and experimental data identified the matrix as having a B i2S e3 dominant part with randomly distributed Cu-intercalated regions having 1Cu-B i2S e3 structure. The precipitates were determined to have 3Cu-B i2S e3 structure.

  6. SYNTHESIS, CHARACTERIZATION AND ANTITUMOR ACTIVITY OF A Ca (II COORDINATION POLYMER BASED ON 3-AMINO-2-PYRAZINECARBOXYLIC ACID

    Directory of Open Access Journals (Sweden)

    XI-SHI TAI

    2015-10-01

    Full Text Available A new Ca(II coordination polymer has been obtained by reaction of Ca(ClO42·H2O with 3-amino-2-pyrazinecarboxylic acid in CH3CH2OH/H2O. It was characterized by IR, 1HNMR, thermal analysis and X-ray single crystal diffraction analysis. X-ray analysis reveals that each Ca(II center is seven-coordination with a N2O5 distorted pentagonal bipyramidal coordination environment. The Ca(II ions are linked through the O atoms of 3-amino-2-pyrazinecarboxylic acid ligands to form 1D chain structure. And then a 3D network structure is constructed by hydrogen bonds and π-π stacking. The antitumor activity of 3-amino-2-pyrazinecarboxylic acid ligand and its Ca(II coordination polymer against human intestinal adenocarcinoma HCT-8 cells, lung adenocarcinoma HCT-116 cells and human lung adenocarcinoma A549 cells line have been investigated.

  7. 3-Monochloropropane-1,2-diol fatty acid esters in commercial deep-fat fried foods.

    Science.gov (United States)

    Arisseto, Adriana Pavesi; Marcolino, Priscila Francisca Corrêa; Vicente, Eduardo

    2015-01-01

    Levels of 3-monochloropropane-1,2-diol (3-MCPD) fatty acid esters were evaluated in commercial deep-fat fried foods from the Brazilian market using a GC-MS method preceded by acid-catalysed methanolysis. A limit of detection of 0.04 mg kg(-1), a limit of quantitation of 0.08 mg kg(-1), mean recoveries varying from 82% to 92%, and coefficients of variation ranging from 2.5% to 5.0% for repeatability and from 3.6% to 6.5% for within-laboratory reproducibility were obtained during in-house validation. The levels of the compounds in the evaluated samples, expressed as free 3-MCPD equivalent, ranged from not detected to 0.99 mg kg(-)(1), and the highest concentrations were observed in samples of chopped onion and garlic. A preliminary estimation of 3-MCPD intake using these occurrence data suggested low risks to human health, but a potential concern may arise in particular cases of consumers of fried food.

  8. Disposable biosensor based on cathodic electrochemiluminescence of tris(2,2-bipyridine)ruthenium(II) for uric acid determination

    Energy Technology Data Exchange (ETDEWEB)

    Ballesta-Claver, J.; Rodríguez-Gómez, R. [ECsens, Department of Analytical Chemistry, Campus Fuentenueva, Faculty of Sciences, University of Granada, E-18071 Granada (Spain); Capitán-Vallvey, L.F., E-mail: lcapitan@ugr.es [ECsens, Department of Analytical Chemistry, Campus Fuentenueva, Faculty of Sciences, University of Granada, E-18071 Granada (Spain)

    2013-04-03

    Highlights: ► Cathodic ECL offers conventional and non-aggressive analysis conditions. ► The ECL hydrogen peroxide/ruthenium complex system for uric acid determination is novel. ► The ruthenium complex is electrochemically immobilized on graphite screen-printed electrodes. ► The quantification of the uric acid is based on a Stern–Volmer type equation. ► The use of the cathodic ECL working methodology reduces interferences during analysis. -- Abstract: A new method for uric acid (UA) determination based on the quenching of the cathodic ECL of the tris(2,2-bipyridine)ruthenium(II)–uricase system is described. The biosensor is based on a double-layer design containing first tris(2,2-bipyridine)ruthenium(II) (Ru(bpy){sub 3}{sup 2+}) electrochemically immobilized on graphite screen-printed cells and uricase in chitosan as a second layer. The uric acid biosensing is based on the ECL quenching produced by uric acid over the cathodic ECL caused by immobilized Ru(bpy){sub 3}{sup 2+} in the presence of uricase. The use of a −1.1 V pulse for 1 s with a dwelling time of 10 s makes it possible to estimate the initial enzymatic rate, which is used as the analytical signal. The Stern–Volmer type calibration function shows a dynamic range from 1.0 × 10{sup −5} to 1.0 × 10{sup −3} M with a limit of detection of 3.1 × 10{sup −6} M and an accuracy of 13.6% (1.0 × 10{sup −4} M, n = 5) as relative standard deviation. Satisfactory results were obtained for urine samples, creating an affordable alternative for uric acid determination.

  9. Solvothermal Synthesis, Crystal Structure, and Magnetic Properties of [Co3(SDA)3(DMF)2]: 2-D Layered Metal-organic Framework Derived from 4,4'-Stilbenedicarboxylic Acid (H2SDA)

    International Nuclear Information System (INIS)

    Park, Gyung Se; Kim, Hyun Uk; Kim, Ki Moon; Lee, Gang Ho; Park, Sang Kyu

    2006-01-01

    A new 2-D coordination polymer has been synthesized and characterized by using a novel 4,4'-stilbene dicarboxylic acid and Co(ClO 4 ) 2 ·6H 2 O. The title complex has an unique Co 3 pin-wheel cluster in which central Co has octahedral geometry and two surrounding Co have tetrahedral geometry. The Co 3 pin-wheel clusters, the building unit, are linked through carboxylate oxygens to generate a 2-D layered coordination polymer in ABCABC packing mode. Variable-temperature magnetic susceptibility data of the title compound confirms the high spin splitting of Co with S=3/2. Syntheses of MOF by using SDA and other transition metal ions, Zn, Cd, and Mn, are on progress in this lab. Metal-organic frameworks (MOF) have attracted much more attention in the past decade owing to their various intriguing framework topologies and potential applications as functional materials in gas storage, separation, and catalysis. Because high framework stability is fundamental and essential property for many practical applications, multi-dentate linkers such as carboxylates have been extensively investigated for the formation of more rigid frameworks due to their ability to aggregate metal ions into M-O-C clusters called secondary building units (SBUs) rather than N-bound organic linkers such as 4,4-bipyridine (bipy)

  10. Crystal structures of 2-(N,N-dimethylaminoalkyl)ferroceneboronic acids and their diol derivatives. The quest for a B-N intramolecular bond in the solid state

    DEFF Research Database (Denmark)

    Norrild, Jens Chr.; Søtofte, Inger

    2001-01-01

    The crystal structures of (S,S)-2-(N,N-dimethyl-1-aminoethyl)ferroceneboronic acid (2), (S,S)-1-(N,N-dimethyl-1-aminoethyl)-2-(4,4,5,5-tetraphenyl-1,3,2-dioxaborolan-2-yl)ferrocene (3), rac-2-(N,N-dimethylaminomethyl)-ferroceneboronic acid (rac-4), (S)-[(1S,2S,3R,5S)-pinane-1,2-diyl] 2-(N...

  11. Constitutive ω-3 fatty acid production in fat-1 transgenic mice and docosahexaenoic acid administration to wild type mice protect against 2,4,6-trinitrobenzene sulfonic acid-induced colitis.

    Science.gov (United States)

    Yum, Hye-Won; Kang, Jing X; Hahm, Ki Baik; Surh, Young-Joon

    2017-06-10

    Omega-3 (ω-3) polyunsaturated fatty acids (PUFAs) are known to have strong anti-inflammatory effects. In the present study, we investigated the protective effects of ω-3 PUFAs on experimentally induced murine colitis. Intrarectal administration of 2.5% 2,4,6-trinitrobenzene sulfonic acid (TNBS) caused inflammation in the colon of wild type mice, but this was less severe in fat-1 transgenic mice that constitutively produce ω-3 PUFAs from ω-6 PUFAs. The intraperitoneal administration of docosahexaenoic acid (DHA), a representative ω-3 PUFA, was also protective against TNBS-induced murine colitis. In addition, endogenously formed and exogenously introduced ω-3 PUFAs attenuated the production of malondialdehyde and 4-hydroxynonenal in the colon of TNBS-treated mice. The effective protection against inflammatory and oxidative colonic tissue damages in fat-1 and DHA-treated mice was associated with suppression of NF-κB activation and cyclooxygenase-2 expression and with elevated activation of Nrf2 and upregulation of its target gene, heme oxygenase-1. Taken together, these results provide mechanistic basis of protective action of ω-3 fatty PUFAs against experimental colitis. Copyright © 2017. Published by Elsevier Inc.

  12. Ca and S K-edge XANES studies of calcite-acid mine water interactions

    Energy Technology Data Exchange (ETDEWEB)

    Myneni, S.C.B.; Perera, R.C.C. [Lawrence Berkeley National Lab., CA (United States)

    1997-04-01

    Heavy metal-rich acidic waters (SO{sub 4}{sup 2{minus}}, AsO{sub 4}{sup 3{minus}}, SeO{sub 4}{sup 2{minus}}, Fe{sup 2+}, Fe{sup 3+}, Al{sup 3+}, Cu{sup 2+}, Zn{sup 2+}, Cd{sup 2+}) and related ochreous coatings are common around abandoned sulfide and coal mine sites. This is mainly caused by the natural weathering of pyrite (FeS{sub 2}), arsenopyrite (FeAsS), and other metal sulfide containing shales. Acid generation in the case of pyrite can be explained by a general reaction: FeS{sub 2} + 3.5 O{sub 2} + H{sub 2}O {leftrightarrow} Fe{sup 2+} + SO{sub 4}{sup 2{minus}} + 2H{sup +}. Also, these low pH waters interact with the soils, and mobilize their soluble elements. One of the common remediation strategies is to allow these acid waters to react with limestone (CaCO{sub 3}-rich rock) and neutralize the pH and precipitate out soluble metals. Yet, the associated problem is the precipitation of Fe and Al oxides and hydroxy sulfate coatings on limestone surfaces, which block calcite reactive sites, and make them ineffective a few hours after initiation of treatment. The main objectives of this research are to examine: (1) the chemistry of limestone surface coatings, and (2) their toxic metal uptake and the conditions that inhibit their formation. Previous molecular studies using X-ray diffraction, and vibrational spectroscopy on limestone surface coatings (sampled from Athens, OH) indicate that the surface-most layer (the layer in contact with water) is composed of schwertmannite (Fe(III)-hydroxy sulfate) like phases. However, white, X-ray amorphous; Al-, sulfate- and carbonate-rich; and Ca-poor phases appeared at the interface between the limestone and the iron oxide coatings. The structure, morphology, and coordination chemistry of component major and trace elements of these white precipitate phases have not previously been examined.

  13. Optoelectronic characterizations of vacuum evaporated Cu 2 SnS 3 ...

    African Journals Online (AJOL)

    ... of non-toxic, cheap earthly abundant, ternary compound of Cu2SnS3 thin film. ... film were investigated by X-Ray Diffraction and Scanning Electron Microscope. ... to determine the electrical properties of the deposited Cu2SnS3 ternary films.

  14. Chiral gels derived from secondary ammonium salts of (1R,3S-(+-camphoric acid

    Directory of Open Access Journals (Sweden)

    Tapas Kumar Adalder

    2010-09-01

    Full Text Available In order to have access to chiral gels, a series of salts derived from (1R,3S-(+-camphoric acid and various secondary amines were prepared based on supramolecular synthon rationale. Out of seven salts prepared, two showed moderate gelation abilities. The gels were characterized by differential scanning calorimetry, table top rheology, scanning electron microscopy, single crystal and powder X-ray diffraction. Structure property correlation based on X-ray diffraction techniques remain inconclusive indicating that some of the integrated part associated with the gelation phenomena requires a better understanding.

  15. Human procaspase-2 phosphorylation at both S139 and S164 is required for 14-3-3 binding

    Czech Academy of Sciences Publication Activity Database

    Kalábová, Dana; Šmídová, Aneta; Petrvalská, Olivia; Alblová, Miroslava; Košek, Dalibor; Man, Petr; Obšil, Tomáš; Obšilová, Veronika

    2017-01-01

    Roč. 493, č. 2 (2017), s. 940-945 ISSN 0006-291X R&D Projects: GA ČR(CZ) GA17-00726S; GA MŠk(CZ) LQ1604; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:67985823 ; RVO:61388971 Keywords : procaspase-2 * 14-3-3 * protein-protein interaction * phosphorylation * caspase-2 Subject RIV: EB - Genetics ; Molecular Biology; CE - Biochemistry (MBU-M) OBOR OECD: Biochemistry and molecular biology; Biochemistry and molecular biology (MBU-M) Impact factor: 2.466, year: 2016

  16. Synthesis of 3-O-propargylated betulinic acid and its 1,2,3-triazoles as potential apoptotic agents

    DEFF Research Database (Denmark)

    Majeed, Rabiya; Sangwan, Payare L; Chinthakindi, Praveen K

    2013-01-01

    Cytotoxic agents from nature are presently the mainstay of anticancer chemotherapy, and the need to reinforce the arsenal of anticancer agents is highly desired. Chemical transformation studies carried out on betulinic acid, through concise 1,2,3-triazole synthesis via click chemistry approach at...

  17. Thermochemistry of aqueous pyridine-3-carboxylic acid (nicotinic acid)

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Elsa M. [Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade de Lisboa, 1749-016 Lisboa (Portugal); Instituto Politecnico de Setubal, ESTBarreiro, Rua Americo da Silva Marinho, 2839-001 Lavradio (Portugal); Rego, Talita S. [Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade de Lisboa, 1749-016 Lisboa (Portugal); Minas da Piedade, Manuel E., E-mail: memp@fc.ul.p [Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade de Lisboa, 1749-016 Lisboa (Portugal)

    2011-06-15

    Research highlights: {yields} We determined the {Delta}{sub sol}H{sub m} of solid nicotinic acid (NA) in water by solution calorimetry. {yields} We determined {Delta}{sub dil}H{sub m} of an aqueous nicotinic acid solution by flow calorimetry. {yields} We determined (aq, {infinity}) for the 3 NA species involved in acid/base equilibria. {yields} We determined the enthalpy of formation of NA(aq) under saturation conditions.. - Abstract: The molar enthalpy of solution of solid nicotinic acid (NA) at T = 298.15 K, to give an aqueous solution of molality m = 3.748 . 10{sup -3} mol {center_dot} kg{sup -1}, was determined as {Delta}{sub sol}H{sub m} = (19,927 {+-} 48) J {center_dot} mol{sup -1}, by solution calorimetry. Enthalpies of dilution, {Delta}{sub dil}H{sub m}, of 0.1005 mol {center_dot} kg{sup -1} aqueous nicotinic acid to yield final solutions with molality in the approximate range (0.03 to 0.09) mol {center_dot} kg{sup -1} were also measured by flow calorimetry. Combining the two sets of data and the results of pH measurements, with values of proton dissociation enthalpies and {Delta}{sub f}H{sub m}{sup 0}(NA, cr) selected from the literature, it was possible to derive the standard molar enthalpies of formation of the three nicotinic acid species involved in protonation/deprotonation equilibria, at infinite dilution: {Delta}{sub f}H{sub m}{sup 0}(HN{sup +}C{sub 5}H{sub 4}COOH.{infinity}H{sub 2}O,aq) = (328.2 {+-} 1.2) kJ {center_dot} mol{sup -1}, {Delta}{sub f}H{sub m}{sup 0}(HN{sup +}C{sub 5}H{sub 4}COO{sup -}.{infinity}H{sub 2}O,aq) = (325.0 {+-} 1.2) kJ {center_dot} mol{sup -1}, and {Delta}{sub f}H{sub m}{sup 0}(NC{sub 5}H{sub 4}COO{sup -}.{infinity}H{sub 2}O,aq) = (313.7 {+-} 1.2) kJ {center_dot} mol{sup -1}. Finally, the enthalpy of solution of nicotinic acid at T = 298.15 K, under saturation conditions (m = 0.138 mol {center_dot} kg{sup -1}), and the standard molar enthalpy of formation of the corresponding solution could also be obtained as {Delta

  18. Dietary exposure of Hong Kong adults to fatty acid esters of 3-monochloropropane-1,2-diol.

    Science.gov (United States)

    Chung, H Y; Chung, Stephen W C; Chan, B T P; Ho, Yuk Yin; Xiao, Ying

    2013-01-01

    A total of 290 individual food samples were collected in Hong Kong, China, for 3-monochloropropane-1,2-diol (3-MCPD) fatty acid esters analysis. Most samples were processed food and in ready-to-eat form. The results show that the levels of 3-MCPD fatty acid esters were high in biscuits, fats and oils, snacks and Chinese pastry with mean bound 3-MCPD levels of 440, 390, 270 and 270 μg kg⁻¹, respectively. The dietary exposures to bound 3-MCPD of average and high adult consumers were estimated to be 0.20 and 0.53 μg kg bw⁻¹ day⁻¹, respectively. The primary toxicological concern of 3-MCPD fatty acid esters is its potential to release 3-MCPD in vivo during digestion in the gastrointestinal tract. 3-MCPD would affect the kidney, the central nervous system and the male reproductive system of rats. Assuming that 100% of the 3-MCPD was released from 3-MCPD fatty acid esters by hydrolysis in the digestive system, the dietary exposures to 3-MCPD for average and high adult consumers were only 10% and 26% of the provisional maximum tolerable daily intake (PMTDI) of 3-MCPD established by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA) (2 μg kg bw⁻¹ day⁻¹), respectively. The results suggest that both average and high adult consumers are unlikely to experience major toxicological effects of 3-MCPD.

  19. 2,4,6-Tri-amino-1,3,5-triazin-1-ium 3-(prop-2-eno-yloxy)propano-ate acrylic acid monosolvate monohydrate.

    Science.gov (United States)

    Sangeetha, V; Kanagathara, N; Chakkaravarthi, G; Marchewka, M K; Anbalagan, G

    2013-05-01

    The asymmetric unit of the title salt, C3H7N6 (+)·C6H7O4 (-)·C3H4O2·H2O, contains a 2,4,6-tri-amino-1,3,5-triazin-1-ium cation, a 3-(prop-2-eno-yloxy)propano-ate anion and acrylic acid and water solvent mol-ecules in a 1:1:1:1 ratio and with each species in a general position. In the crystal, the components are linked into a supra-molecular layer in the bc plane via a combination of O-H⋯O, N-H⋯N and N-H⋯O hydrogen bonding. The crystal studied was a non-merohedral twin, the minor component contribution being approximately 26%.

  20. PLA2 - a major regulator of volume-sensitive taurine release in NIH3T3 fibroblasts

    DEFF Research Database (Denmark)

    Lambert, I. H.

    2006-01-01

    -lipoxygenase (5-LO) system is prevented by the 5-LO inhibitor ETH 615-139 and is reduced under hypertonic conditions. Exposure to the amphiphilic bee venom peptide melittin, which has no effect on the kinetic properties of PLA2 but promotes substrate replenishment, induces release of arachidonic acid...... conditions but has only a minor effect on the melittin-induced taurine efflux under hypertonic conditions. Bromoenol lactone and manoalide, known inhibitors of Ca2+-independent phospholipase A2 (iPLA2) and secretory phospholipase A2 (sPLA2), respectively, reduce arachidonic acid and taurine release from NIH3......T3 cells under hypotonic conditions and following addition of melittin. It is suggested that iPLA2/sPLA2 activity is responsible for the volume-sensitivity of taurine release in NIH3T3 mouse fibroblasts....

  1. (Carbonyl-1κC)bis-[2,3(η)-cyclo-penta-dien-yl][μ(3)-(S-methyl trithio-carbonato)methylidyne-1:2:3κC,S'':C:C](triphenyl-phosphine-1κP)(μ(3)-sulfido-1:2:3κS)dicobalt(II)iron(II) trifluoro-methane-sulfonate.

    Science.gov (United States)

    Manning, Anthony R; McAdam, C John; Palmer, Anthony J; Simpson, Jim

    2008-04-10

    The asymmetric unit of the title compound, [FeCo(2)(C(5)H(5))(2)(C(3)H(3)S(3))S(C(18)H(15)P)(CO)]CF(3)SO(3), consists of a triangular irondicobalt cluster cation and a trifluoro-methane-sulfonate anion. In the cation, the FeCo(2) triangle is symmetrically capped on one face by an S atom and on the other by a C atom linked to a methyl trithio-carbonate residue that bridges the Fe-C bond. Each Co atom carries a cyclo-penta-dienyl ligand while the Fe atom coordinates to one carbonyl and one triphenyl-phosphine ligand. In the crystal structure, the cation is linked to the anion by a number of weak non-classical C-H⋯O and C-H⋯F hydrogen bonds and weak S⋯O (3.317 Å) and S⋯F (3.198 Å) inter-actions. The structure is further stabilized by additional inter-molecular C-H⋯O, C-H⋯F and O⋯O (2.942 Å) contacts, together with an unusual S⋯π(Cp) inter-action (S⋯centroid distance = 3.385 Å), generating an extended network.

  2. Facile fabrication of Bi{sub 2}S{sub 3}/SnS{sub 2} heterojunction photocatalysts with efficient photocatalytic activity under visible light

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Xiaomin; Huang, Guanbo [Department of Chemistry, School of Science, Tianjin University, Tianjin 300072 (China); Gao, Haihuan [Tianjin Fourth Middle School, Tianjin 300021 (China); Pan, Cheng; Wang, Huan [Department of Chemistry, School of Science, Tianjin University, Tianjin 300072 (China); Yan, Jing, E-mail: yanjingls2012@163.com [Department of Chemistry, School of Science, Tianjin University, Tianjin 300072 (China); Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072 (China); Liu, Yu [Department of Chemistry, School of Science, Tianjin University, Tianjin 300072 (China); Qiu, Haixia [Department of Chemistry, School of Science, Tianjin University, Tianjin 300072 (China); Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072 (China); Ma, Ning [Department of Chemistry, School of Science, Tianjin University, Tianjin 300072 (China); Gao, Jianping [Department of Chemistry, School of Science, Tianjin University, Tianjin 300072 (China); Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072 (China)

    2016-07-25

    In this work, Bi{sub 2}S{sub 3}/SnS{sub 2} heterojunction photocatalysts were prepared by combining a hydrothermal technique and a facile in situ growth method. The nanocomposites were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, inductively coupled plasma spectroscopy, X-ray photoelectron spectroscopy, UV–Vis diffusion reflectance spectroscopy and room-temperature photoluminescence spectra. Their photocatalytic performances were evaluated by degrading methyl orange (MO) in aqueous solution (50 mg/L) under visible light (λ > 420 nm) irradiation. It was found that when the mass percentage of Bi{sub 2}S{sub 3} in Bi{sub 2}S{sub 3}/SnS{sub 2} was 7.95 wt%, the as-prepared Bi{sub 2}S{sub 3}/SnS{sub 2} nanocomposite showed the best photocatalytic activity for the degradation of MO. The highly improved performance of the Bi{sub 2}S{sub 3}/SnS{sub 2} nanocomposite was mainly ascribed to the efficient charge separation. - Highlights: • Facile fabrication of novel Bi{sub 2}S{sub 3}/SnS{sub 2} heterojunction photocatalysts. • High-performance photocatalyst for the degradation of organic pollutants. • Good recyclability of catalyst without photo-corrosion. • The photocatalytic mechanism was proposed.

  3. Niflumic acid alters gating of HCN2 pacemaker channels by interaction with the outer region of S4 voltage sensing domains.

    Science.gov (United States)

    Cheng, Lan; Sanguinetti, Michael C

    2009-05-01

    Niflumic acid, 2-[[3-(trifluoromethyl)phenyl]amino]pyridine-3-carboxylic acid (NFA), is a nonsteroidal anti-inflammatory drug that also blocks or modifies the gating of many ion channels. Here, we investigated the effects of NFA on hyperpolarization-activated cyclic nucleotide-gated cation (HCN) pacemaker channels expressed in X. laevis oocytes using site-directed mutagenesis and the two-electrode voltage-clamp technique. Extracellular NFA acted rapidly and caused a slowing of activation and deactivation and a hyperpolarizing shift in the voltage dependence of HCN2 channel activation (-24.5 +/- 1.2 mV at 1 mM). Slowed channel gating and reduction of current magnitude was marked in oocytes treated with NFA, while clamped at 0 mV but minimal in oocytes clamped at -100 mV, indicating the drug preferentially interacts with channels in the closed state. NFA at 0.1 to 3 mM shifted the half-point for channel activation in a concentration-dependent manner, with an EC(50) of 0.54 +/- 0.068 mM and a predicted maximum shift of -38 mV. NFA at 1 mM also reduced maximum HCN2 conductance by approximately 20%, presumably by direct block of the pore. The rapid onset and state-dependence of NFA-induced changes in channel gating suggests an interaction with the extracellular region of the S4 transmembrane helix, the primary voltage-sensing domain of HCN2. Neutralization (by mutation to Gln) of any three of the outer four basic charged residues in S4, but not single mutations, abrogated the NFA-induced shift in channel activation. We conclude that NFA alters HCN2 gating by interacting with the extracellular end of the S4 voltage sensor domains.

  4. Synthesis, characterization and biocidal activity of new organotin complexes of 2-(3-oxocyclohex-1-enyl)benzoic acid.

    Science.gov (United States)

    Vieira, Flaviana T; de Lima, Geraldo M; Maia, José R da S; Speziali, Nivaldo L; Ardisson, José D; Rodrigues, Leonardo; Correa, Ary; Romero, Oscar B

    2010-03-01

    The reaction of 1,3-cyclohexadione with 2-aminobenzoic acid has produced the 2-(3-oxocyclohex-1-enyl)benzoic acid (HOBz). Subsequent reactions of the ligand with organotin chlorides led to [Me(2)Sn(OBz)O](2) (1), [Bu(2)Sn(OBz)O](2) (2), [Ph(2)Sn(OBz)O](2) (3), [Me(3)Sn(OBz)] (4), [Bu(3)Sn(OBz)] (5) and [Ph(3)Sn(OBz)] (6). All complexes have been fully characterized. In addition the structure of complexes (2) and (4) have been authenticated by X-ray crystallography. The biological activity of all derivatives has been screened against Cryptococcus neoformans and Candida albicans. In addition we have performed toxicological testes employing human kidney cell. The complexes (3), (5) and (6) displayed the best values of inhibition of the fungus growing, superior to ketoconazole. Compound (5) presented promising results in view of the antifungal and cytotoxicity assays. Copyright (c) 2009 Elsevier Masson SAS. All rights reserved.

  5. Study of the interactions between Eu(III) and Al2O3 particles in the presence of phenolic acids

    International Nuclear Information System (INIS)

    Moreau, P.

    2012-01-01

    In the framework of environmental pollution by radionuclides, this work was focused on the interactions occurring in systems containing europium(III) - as a chemical analogue for the actinides Am(III) and Cm(III) -, phenolic acids - lignin degradation products and anti-fungi, naturally occurring in soils, and alumina - representative of sorption sites found in the environment. This study was conducted at different scales of description: the macroscopic scale - to quantify Eu(III) and/or phenolic acids adsorption onto the mineral surface -, and the microscopic scale - to study the chemical environment of Eu(III) using Time-Resolved Luminescence Spectroscopy (TRLS). First, the binary systems, i.e. systems containing only two entities among the three previously cited, were characterized. Complexation constants of Eu(III) by three phenolic acids (4-hydroxybenzoic, 3,4-dihydroxybenzoic, and 3,4,5-trihydroxybenzoic acids) were determined and quantum calculations (DFT) were carried out on La(III)-acid complex analogues. Sorption of the acids onto aluminol sites was modelled using surface complexation concepts. Analyses of two ternary systems (containing 4-hydroxybenzoic and 3,4-dihydroxybenzoic acids) revealed synergistic processes for Eu(III) and phenolic acids sorption onto Al 2 O 3 . A spectral fingerprint of ternary complex involving Eu(III)/4-hydroxybenzoic acid/Al 2 O 3 surface sites was evidenced. (author) [fr

  6. Anodic Aluminum Oxide Membrane-Assisted Fabrication of ?-In2S3Nanowires

    OpenAIRE

    Shi, Jen-Bin; Chen, Chih-Jung; Lin, Ya-Ting; Hsu, Wen-Chia; Chen, Yu-Cheng; Wu, Po-Feng

    2009-01-01

    Abstract In this study, β-In2S3nanowires were first synthesized by sulfurizing the pure Indium (In) nanowires in an AAO membrane. As FE-SEM results, β-In2S3nanowires are highly ordered, arranged tightly corresponding to the high porosity of the AAO membrane used. The diameter of the β-In2S3nanowires is about 60 nm with the length of about 6–8 μm. Moreover, the aspect ratio of β-In2S3nanowires is up to 117. An EDS analysis revealed the β-In2S3nanowires with ...

  7. The crystal structure of Cs{sub 2}S{sub 2}O{sub 3}.H{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Winkler, Verena; Schlosser, Marc; Pfitzner, Arno [Regensburg Univ. (Germany). Inst. fuer Anorganische Chemie

    2016-08-01

    A reinvestigation of the alkali metal thiosulfates has led to the new phase Cs{sub 2}S{sub 2}O{sub 3}.H{sub 2}O. At first cesium thiosulfate monohydrate was obtained as a byproduct of the synthesis of Cs{sub 4}In{sub 2}S{sub 5}. Further investigations were carried out using the traditional synthesis reported by J. Meyer and H. Eggeling. Cs{sub 2}S{sub 2}O{sub 3}.H{sub 2}O crystallizes in transparent, colorless needles. The crystal structure of the title compound was determined by single crystal X-ray diffraction at room temperature: space group C2/m (No. 12), unit cell dimensions: a = 11.229(4), b = 5.851(2), c = 11.260(5) Aa, β = 95.89(2) , with Z = 4 and a cell volume of V = 735.9(5) Aa{sup 3}. The positions of all atoms including the hydrogen atoms were located in the structure refinement. Cs{sub 2}S{sub 2}O{sub 3}.H{sub 2}O is isotypic with Rb{sub 2}S{sub 2}O{sub 3}.H{sub 2}O. Isolated tetrahedra [S{sub 2}O{sub 3}]{sup 2-} are coordinated by the alkali metal cations, and in addition they serve as acceptors for hydrogen bonding. For both Cs atoms the shortest distances are observed to oxygen atoms of the S{sub 2}O{sub 3}{sup 2-} anions whereas the terminating sulfur atom has its shortest contacts to the water hydrogen atoms. Thus, an extended hydrogen bonding network is formed. The title compound has also been characterized by IR spectroscopy. IR spectroscopy reveals the vibrational bands of the water molecules at 3385 cm{sup -1}. They show a red shift in the OH stretching and bending modes as compared to free water. This is due both to the S..H hydrogen bonding and to the coordination of H{sub 2}O molecules to the cesium atoms.

  8. 3-[(3-(Trimethoxysilylpropylthio]propane-1-oxy-sulfonic acid: An efficient recyclable heterogeneous catalyst for the synthesis of 3,4-dihydropyrimidin-2(1H-ones/thiones

    Directory of Open Access Journals (Sweden)

    Srinivasa Rao Jetti

    2017-05-01

    Full Text Available An efficient method for the synthesis of 3,4-dihydropyrimidin-2(1H-ones and thiones through one-pot three-component reaction of ethyl acetoacetate, aryl aldehyde and urea or thiourea in ethanol using 3-[(3-(trimethoxysilylpropylthio]propane-1-oxy-sulfonic acid as catalyst is described. The use of 3-[(3-(trimethoxysilylpropylthio]propane-1-oxy-sulfonic acid as a catalyst offers several advantages such as high yields, short reaction times, mild reaction condition and a recyclable catalyst with a very easy work up.

  9. Synthesis, physical-chemical properties of 2-((5-(adamantan-1-yl-4-R-4H-1,2,4-triazole-3-ylthioacetic acid esters

    Directory of Open Access Journals (Sweden)

    V. M. Odyntsova

    2017-04-01

    Full Text Available The nitrogen-containing heterocyclic systems from the class of 1,2,4-triazole derivatives, which exhibit wide range of actions, occupy special place among the variety of heterocyclic compounds. Derived biologically active substances are actively introduced into practice as new original and effective drugs. We were interested in esters of 2-((5-(adamantan-1-yl-4-R-4H-1,2,4-triazole-3-ylthioacetic acids, which exhibit high biological activity and can be intermediates for the synthesis of amides, hydrazides, ylidenderivatives of corresponding acids. The aim of this work is the synthesis of new esters of 2-((5-(adamantan-1-yl-4-R-4H-1,2,4-triazole-3-ylthioacetic acids and the establishment of their physical-chemical properties. Materials and methods. Melting point was determined by open capillary method on the device OptiMelt MPA100. The elemental composition of the synthesized compounds was determined on the universal analyzer ElementarVario ЕL cube (CHNS (standard – sulfanilamide. 1H NMR spectra were recorded on spectrometer Varian Mercury VX-200 (1H, 200 MHz in the solvent dimethyl sulfoxide-d6 (tetramethylsilane internal standard and decoded using a program ADVASP(tm Analyzer program (Umatek International Inc.. Chromato-mass-spectral studies were performed on hazarding chromatograph Agilent 1260 Infinity HPLC equipped with mass spectrometer Agilent 6120 (ionization electro-spray (ESI. The results and discussion. Synthesis of 11 new compounds, namely esters of 2-((5-(adamantan-1-yl-4-R-4H-1,2,4-triazole-3-ylthioacetic acids was carried out by two methods. According to the A method the alkylation of previously synthesized 3-(adamantan-1-yl-1H-1,2,4-triazole-5-thiol was performed with the use of corresponding methyl ester of 2-chloroacetic acid and the presence of equivalent amount of sodium hydroxide. The B method involves the etherification of 2-((5-(adamantan-1-yl-4-R-4H-1,2,4-triazole-3-ylthioacetic acid with the use of methyl, ethyl, i

  10. 2-([1,2,4]triazolo[1,5-c]quinazolin-2-yl-alkyl-(alkaryl-, aryl--amines and their derivatives. (3Н-quinazolin-4-ylidenhydrazides (1,3-dioxo-1,3-dihydro-2H-isoindol-2-ylalkyl-(alkaryl-, aryl-carboxylic acids: features of synthesis, modification and ant

    Directory of Open Access Journals (Sweden)

    Yu. V. Martynenko

    2016-08-01

    Full Text Available The combination of different «pharmacophore» components in one structure connected via «linker» functional groups is one of the major and justified approaches for the synthesis of new biologically active substances. In this area (3Н-quinazoline-4-ylidenhydrazides (1,3-dioxo-1,3-dihydro-2H-іsoindol-2-yl-alkyl-(aralkyl-, aryl-carboxylic acids are the most interesting compounds. They contain quinazoline and іsoindole fragments united through аlkyl, аlkaryl and аryl groups and furthermore can be used for the synthesis of new heterocycles. Aim: The purpose of this work is to find antimicrobial and antifungal agents among (3H-quinazolin-4-ylidenehydrazides (1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl-alkyl-(alkaryl-, aryl-carboxylic acids and their fused derivatives and to establish physical-chemical properties of these compounds and to correlate «structure – activity relationship» for structure optimization. Methods and results. The study of microbiological activity was conducted by disco-diffusion method on Mueller-Hinton agar on the following strains of microorganisms: gram-positive cocci (Staphylococcus aureus ATCC 25923, Enterococcus aeruginosa, E. faecalis ATCC 29212, gram-negative bacteria (Pseudomonas aeruginosa PSS27853, Escherichia coli ATCC 25922, facultative anaerobic gram-negative bacteria (Klebsiella pneumoniaе and fungi (Candida albicans ATCC 885653. Conclusion. The protected aminoacids were used to synthesize unknown (3H-quinazolin-4-ylidenehydrazides (1,3-dioxo-1,3-dihydroisoindolo-2-yl-alkyl-(alkaryl-, aryl-carboxylic acids in the reactions of nucleophilic substitution for the first time. While new [1,2,4]triazolo[1,5-c]quinazolin-2-yl-alkyl-(alkaryl-, aryl-- isoindol-1,3(2H-diones were received by heterocyclization of the last. Structure and identity have been confirmed by elemental analysis, physical and chemical methods (1H NMR spectroscopy, mass-spectrometry. Analysis of the results of microbiological study shows, that

  11. Rational Design, Synthesis and Pharmacological Evaluation of the (2R)- and (2S)-Stereoisomers of 3-(2-Carboxypyrrolidinyl)-2-methyl Acetic Acid as Ligands for the Ionotropic Glutamate Receptors

    DEFF Research Database (Denmark)

    Rasmussen, Julie; Storgaard, Morten; Pickering, Darryl S

    2011-01-01

    In this paper we describe the rational design, synthesis and pharmacological evaluation of two new stereoisomeric (S)-glutamate (Glu) analogues. The rational design was based on hybrid structures of the natural product kainic acid, a synthetic analogue CPAA and the high-affinity Glu analogue SYM...

  12. Expanding atmospheric acid deposition in China from the 1990s to the 2010s

    Science.gov (United States)

    Yu, Haili; Wang, Qiufeng

    2017-04-01

    Atmospheric acid deposition is considered a global environmental issue. China has been experiencing serious acid deposition, which is anticipated to be more serious with the country's economic development and increasing consumption of fossil fuels in recent decades. By collecting nationwide data on pH and concentrations of sulfate (SO42-) and nitrate (NO3-) in precipitation between 1980 and 2014 in China, we explored the spatiotemporal variations of precipitation acid deposition (bulk deposition) and their influencing factors. Our results showed that average precipitation pH values were 4.86 and 4.84 in the 1990s and 2010s, respectively. This suggests that precipitation acid deposition in China has not seriously changes. Average SO42- deposition declined from 30.73 to 28.61 kg S ha-1 yr-1 but average NO3- deposition increased from 4.02 to 6.79 kg N ha-1 yr-1. Specifically, the area of severe precipitation acid deposition in southern China has shrunk to some extent as a result of decreasing pollutant emissions, whereas the area of moderate precipitation acid deposition has expanded in northern China, associated with rapid industrial and transportation development. Significant positive correlations have been found between precipitation acid deposition, energy consumption, and rainfall. Our findings provide a comprehensive evaluation of the spatiotemporal dynamics of precipitation acid deposition in China over past three decades, and confirm the idea that strategies implemented to save energy and reduce pollutant emissions in China have been effective in alleviating precipitation acid deposition. These findings might be used to demonstrate how developing countries could achieve economic development and environmental protection through the implementation of advanced technologies to reduce pollutant emissions.

  13. (2Alpha,3beta)-2,3-dihydroxyolean-12-en-28-oic acid, a new natural triterpene from Olea europea, induces caspase dependent apoptosis selectively in colon adenocarcinoma cells.

    Science.gov (United States)

    Reyes, Fernando J; Centelles, Josep J; Lupiáñez, José A; Cascante, Marta

    2006-11-27

    Triterpenoids are known to induce apoptosis and to be anti-tumoural. Maslinic acid, a pentacyclic triterpene, is present in high concentrations in olive pomace. This study examines the response of HT29 and Caco-2 colon-cancer cell lines to maslinic-acid treatment. At concentrations inhibiting cell growth by 50-80% (IC50HT29=61+/-1 microM, IC80HT29=76+/-1 microM and IC50Caco-2=85+/-5 microM, IC80Caco-2=116+/-5 microM), maslinic acid induced strong G0/G1 cell-cycle arrest and DNA fragmentation, and increased caspase-3 activity. However, maslinic acid did not alter the cell cycle or induce apoptosis in the non-tumoural intestine cell lines IEC-6 and IEC-18. Moreover, maslinic acid induced cell differentiation in colon adenocarcinoma cells. These findings support a role for maslinic acid as a tumour suppressant and as a possible new therapeutic tool for aberrant cell proliferation in the colon. In this report, we demonstrate for the first time that, in tumoural cancer cells, maslinic acid exerts a significant anti-proliferation effect by inducing an apoptotic process characterized by caspase-3 activation by a p53-independent mechanism, which occurs via mitochondrial disturbances and cytochrome c release.

  14. Pr{sub 3}S{sub 2}Cl{sub 2}[AsS{sub 3}]: a praseodymium(III) sulfide chloride thioarsenate(III) with double chains of condensed [SPr{sub 4}]{sup 10+} tetrahedra

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Dong-Hee [Institute for Inorganic Chemistry, University of Stuttgart (Germany); Department of Chemistry, University of Waterloo, ON (Canada); Korea Research Institute of Standards and Science (KRISS), Daejeon (Korea, Republic of); Ledderboge, Florian; Schleid, Thomas [Institute for Inorganic Chemistry, University of Stuttgart (Germany); Kleinke, Holger [Department of Chemistry, University of Waterloo, ON (Canada)

    2015-02-15

    Single crystals of Pr{sub 3}S{sub 2}Cl{sub 2}[AsS{sub 3}] were obtained by reacting praseodymium sesquisulfide and trichloride with arsenic and sulfur (molar ratio: 7:4:6:9) in torch-sealed evacuated silica ampoules at 850 C for a week and subsequent slow cooling to room temperature. The transparent, pale yellowish green platelets crystallize monoclinically (Pr{sub 3}S{sub 2}Cl{sub 2}[AsS{sub 3}]: a = 2190.96(9) pm, b = 685.49(3) pm, c = 701.87(3) pm, β = 98.752(3) ) in the non-centrosymmetric space group Cc with Z = 4. The crystal structure of Pr{sub 3}S{sub 2}Cl{sub 2}[AsS{sub 3}] comprises three crystallographically different Pr{sup 3+} cations. (Pr1){sup 3+} and (Pr2){sup 3+} exhibit bicapped trigonal prismatic environments of five sulfur and three chlorine atoms (C.N. = 8) each, whereas only seven sulfur atoms arranged as capped trigonal prism (C.N. = 7) are present in the case of (Pr3){sup 3+}. Two of the five crystallographically different sulfur atoms (S1 and S2) are coordinated by four Pr{sup 3+} cations, each in the shape of slightly distorted [SPr{sub 4}]{sup 10+} tetrahedra (d(S-Pr) = 278-294 pm). Hence, the crystal structure of Pr{sub 3}S{sub 2}Cl{sub 2}[AsS{sub 3}] contains double chains with the composition {sup 1}{sub ∞}{[S_2Pr_3]"5"+}, consisting of two parallel edge-fused chains of anti-SiS{sub 2}-analogous single strands {sup 1}{sub ∞}{[SPr_2]"4"+}, formed by trans-edge sharing [SPr{sub 4}]{sup 10+} tetrahedra. The arrangement of the {sup 1}{sub ∞}{[S_2Pr_3]"5"+} double chains running along [001] can be described as a hexagonal rod-packing. Chloride anions (Cl1 and Cl2) as well as the isolated, ψ{sup 1}-tetrahedral thioarsenate(III) groups [AsS{sub 3}]{sup 3-} (d(As-S) = 228-229 pm) consisting of three sulfur atoms (S3, S4, and S5) and an As{sup 3+} cation carrying a stereochemically active non-bonding electron pair take care of the three-dimensional interconnection and the charge balance of the {sup 1}{sub ∞}{[S_2Pr_3]"5"+} double

  15. Pr4N2S3 and Pr4N2Se3: two non-isostructural praseodymium(iii) nitride chalcogenides

    International Nuclear Information System (INIS)

    Lissner, Falk; Schleid, Thomas

    2005-01-01

    The non-isostructural nitride chalcogenides of praseodymium, Pr 4 N 2 S 3 and Pr 4 N 2 Se 3 , are formed by the reaction of the praseodymium metal with sodium azide (NaN 3 ), praseodymium trihalide (PrX 3 ; X = Cl, Br, I) and the respective chalcogen (sulfur or selenium) at 900 C in evacuated silica ampoules after seven days. Both crystallize monoclinically in space group C2/c (Pr 4 N 2 S 3 : a = 1788.57(9), b = 986.04(5), c = 1266.49(6) pm, β = 134.546(7) , Z = 8; Pr 4 N 2 Se 3 : a = 1311.76(7), b = 1017.03(5), c = 650.42(3) pm, β = 90.114(6) , Z = 4). The crystal structures of both compounds show a layered construction, dominated by N 3- -centred (Pr 3+ ) 4 tetrahedra which share a common edge first. Continuing linkage of the so resulting bitetrahedral [N 2 Pr 6 ] 12+ units via the non-connected vertices to layers according to [stack ∞ 2 ]{[N(Pr) 2/2 e (Pr') 2/2 v ] 3+ } forms different kinds of tetrahedral nets which can be described as layers consisting of ''four- and eight-rings'' for Pr 4 N 2 S 3 and as layers of ''six-rings'' for Pr 4 N 2 Se 3 . Whereas the crystal structure of Pr 4 N 2 S 3 exhibits four different Pr 3+ cations with coordination numbers of six (2 x) and seven (2 x) against N 3- and S 2- , the number of cations in the nitride selenide (Pr 4 N 2 Se 3 ) is reduced to half (Pr1 and Pr2) also having six- and sevenfold anionic coordination spheres. Further motifs for the connection of [NM 4 ] 9+ tetrahedra in crystal structures of nitride chalcogenides and halides of the rare-earth elements with ratios of N: M = 1: 2 are presented and discussed. (Abstract Copyright [2005], Wiley Periodicals, Inc.) [de

  16. Sulfur-containing constituents and one 1H-pyrrole-2-carboxylic acid derivative from pineapple [Ananas comosus (L.) Merr.] fruit.

    Science.gov (United States)

    Zheng, Zong-Ping; Ma, Jinyu; Cheng, Ka-Wing; Chao, Jianfei; Zhu, Qin; Chang, Raymond Chuen-Chung; Zhao, Ming; Lin, Zhi-Xiu; Wang, Mingfu

    2010-12-01

    Two sulfur-containing compounds, (S)-2-amino-5-((R)-1-carboxy-2-((E)-3-(4-hydroxy-3-methoxyphenyl)allylthio)ethyl-amino)-5-oxopentanoic acid (1) and (S)-2-amino-5-((R)-1-(carboxymethylamino)-3-((E)-3-(4-hydroxyphenyl)allylthio)-1-oxopropan-2-ylamino)-5-oxopentanoic acid (2), and one 1H-pyrrole-2-carboxylic acid derivative, 6-(3-(1H-pyrrole-2-carbonyloxy)-2-hydroxypropoxy)-3,4,5-trihydroxy-tetrahydro-2H-pyran-2-carboxylic acid (3), together with eighteen known phenolic compounds, were isolated from the fruits of pineapple. Their structures were elucidated by a combination of spectroscopic analyses. Some of these compounds showed inhibitory activities against tyrosinase. The half maximal inhibitory concentration values of compounds 1, 4, 5, 6, 7 are lower than 1 mM. These compounds may contribute to the well-known anti-browning effect of pineapple juice and be potential skin whitening agents in cosmetic applications. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. Acid Gas to Syngas (AG2S™) technology applied to solid fuel gasification: Cutting H_2S and CO_2 emissions by improving syngas production

    International Nuclear Information System (INIS)

    Bassani, Andrea; Pirola, Carlo; Maggio, Enrico; Pettinau, Alberto; Frau, Caterina; Bozzano, Giulia; Pierucci, Sauro; Ranzi, Eliseo; Manenti, Flavio

    2016-01-01

    Highlights: • Coal gasification with improved yield and reduced emissions. • AG2S™ process converts H_2S and CO_2 into syngas, elemental sulfur and water. • Techno-economic simulation of AG2S™ process is carried out. • Industrial case-study on the Sotacarbo S.p.A. gasification pilot plant is proposed. - Abstract: The paper deals with the application of the novel Acid Gas To Syngas (AG2S™) technology to the gasification of solid fuels. The AG2S technology is a completely new effective route of processing acid gases: H_2S and CO_2 are converted into syngas (CO and H_2) by means of a regenerative thermal reactor. To show the application of the AG2S technology, modeling and simulation advances for gasification systems are initially discussed. The multi-scale, multi-phase, and multi-component coal gasification system is described by means of detailed kinetic mechanisms for coal pyrolysis, char heterogeneous reactions and for successive gas-phase reactions. These kinetic mechanisms are then coupled with transport resistances resulting in first-principles dynamic modeling of non-ideal reactors of different types (e.g., downdraft, updraft, traveling grate), also including the catalytic effect of ashes. The generalized approach pursued in developing the model allows characterizing the main phenomena involved in the coal gasification process, including the formation of secondary species (e.g., COS, CS_2). This tool is here further validated on literature data and, then, adopted to demonstrate the AG2S effectiveness, where H_2S and CO_2 emissions are reduced with an increase of syngas production. The resulting process solution is more economically appealing with respect to the traditional Claus process and finds several application areas.

  18. Molecular pharmacology of homologues of ibotenic acid at cloned metabotropic glutamic acid receptors

    DEFF Research Database (Denmark)

    Bräuner-Osborne, Hans; Nielsen, B; Krogsgaard-Larsen, P

    1998-01-01

    We have studied the effects of the enantiomers of 2-amino-3-(3-hydroxyisoxazol-5-yl)propionic acid (homoibotenic acid, HIBO) and analogues substituted with a methyl, bromo or butyl group in the four position of the ring at cloned metabotropic glutamate (mGlu) receptors expressed in Chinese hamster...... ovary (CHO) cells. In contrast to the parent compound ibotenic acid, which is a potent group I and II agonist, the (S)-forms of homoibotenic acid and its analogues are selective and potent group I antagonists whereas the (R)-forms are inactive both as agonists and antagonists at group I, II, and III m......Glu receptors. Interestingly, (S)-homoibotenic acid and the analogues display equal potency at both mGlu1alpha and mGlu5a with Ki values in the range of 97 to 490 microM, (S)-homoibotenic acid and (S)-2-amino-3-(4-butyl-3-hydroxyisoxazol-5-yl)propionic acid [(S)-4-butylhomoibotenic acid] displaying the lowest...

  19. The role of adrenal hormones in the activation of tryptophan 2,3-dioxygenase by nicotinic acid in rat liver.

    Science.gov (United States)

    Sainio, E L

    1997-09-01

    In this study, our previous finding that nicotinic acid activates tryptophan 2,3-dioxygenase as strongly as tryptophan was investigated in further detail. This study focused on the role of the adrenals in the activation process. Adrenalectomy abolished the activation due to nicotinic acid, but not the activation caused by tryptophan. The role of corticoids and/or adrenomedullary hormones in the enzyme activation was studied, by supplementing these hormones in adrenalectomized rats using minipumps implanted under the skin. The results showed that the enhanced activity of tryptophan 2,3-dioxygenase caused by nicotinic acid was partly restored by adrenaline following adrenalectomy but not by corticosterone supplementation. The results were supported by further experiments in which the rats were treated with adrenaline or corticosterone intraperitoneally before nicotinic acid administration. The conclusion that adrenaline participates in the regulation of tryptophan 2,3-dioxygenase should promote further study to determine whether adrenaline is a general modulator of this enzyme. This experimental model generated new information on the activation mechanism of tryptophan 2,3-dioxygenase by nicotinic acid.

  20. Permutation-symmetric three-particle hyper-spherical harmonics based on the S3⊗SO(3rot⊂O(2⊗SO(3rot⊂U(3S2⊂O(6 subgroup chain

    Directory of Open Access Journals (Sweden)

    Igor Salom

    2017-07-01

    Full Text Available We construct the three-body permutation symmetric hyperspherical harmonics to be used in the non-relativistic three-body Schrödinger equation in three spatial dimensions (3D. We label the state vectors according to the S3⊗SO(3rot⊂O(2⊗SO(3rot⊂U(3S2⊂O(6 subgroup chain, where S3 is the three-body permutation group and S2 is its two element subgroup containing transposition of first two particles, O(2 is the “democracy transformation”, or “kinematic rotation” group for three particles; SO(3rot is the 3D rotation group, and U(3,O(6 are the usual Lie groups. We discuss the good quantum numbers implied by the above chain of algebras, as well as their relation to the S3 permutation properties of the harmonics, particularly in view of the SO(3rot⊂SU(3 degeneracy. We provide a definite, practically implementable algorithm for the calculation of harmonics with arbitrary finite integer values of the hyper angular momentum K, and show an explicit example of this construction in a specific case with degeneracy, as well as tables of K≤6 harmonics. All harmonics are expressed as homogeneous polynomials in the Jacobi vectors (λ,ρ with coefficients given as algebraic numbers unless the “operator method” is chosen for the lifting of the SO(3rot⊂SU(3 multiplicity and the dimension of the degenerate subspace is greater than four – in which case one must resort to numerical diagonalization; the latter condition is not met by any K≤15 harmonic, or by any L≤7 harmonic with arbitrary K. We also calculate a certain type of matrix elements (the Gaunt integrals of products of three harmonics in two ways: 1 by explicit evaluation of integrals and 2 by reduction to known SU(3 Clebsch–Gordan coefficients. In this way we complete the calculation of the ingredients sufficient for the solution to the quantum-mechanical three-body bound state problem.

  1. Effects of Gibberellic acid and 2,4-Dichlorophenoxy Acetic Acid ...

    African Journals Online (AJOL)

    dichlorophenoxyacetic acid (2,4-D) and gibberellic acid (GA3) spray on vegetative and reproductive growth components of tomato. The experiment consists of two tomato varieties, one processing (Roma VF) and one fresh market (Fetan), three levels of 2,4-D (0, ...

  2. THE INFLUENCE OF THIOSEMICARBAZONE 2,3-DIHYDROXYBENZALDEHYDE ON CATALYTIC CURRENTS IN THE SYSTEM MOLYBDENUM (VI – POTASSIUM CHLORATE IN ACID SULFATE SOLUTIONS

    Directory of Open Access Journals (Sweden)

    Ludmila Chiriac

    2011-06-01

    Full Text Available The polarographic catalytic current in acid solutions of Mo(VI, thiosemicarbazone 2,3-dihydroxybenzaldehyde (TSC 2,3-DHBA and chlorate ions has been investigated. The scheme of reactions, taking place in the solutions and on the electrode, has been proposed. The increase of the catalytic current is explained by the formation of an active intermediate complex [Mo(V×TSC 2,3-DHBA (ClO-3]. The rate constant of this complex formation K = 2.56 × 106 mol-1×dm3×s-1, the activation energy Ea = 15.9 kcal×mol-1 and the reaction activation entropy ∆Sa¹ = -23.5 e.u. have been calculated.

  3. (R-(+-α-Lipoic acid protected NG108-15 cells against H2O2-induced cell death through PI3K-Akt/GSK-3β pathway and suppression of NF-κβ-cytokines

    Directory of Open Access Journals (Sweden)

    Kamarudin MNA

    2014-10-01

    Full Text Available Muhamad Noor Alfarizal Kamarudin, Nur Afiqah Mohd Raflee, Sharifah Salwa Syed Hussein, Jia Ye Lo, Hadi Supriady, Habsah Abdul KadirInstitute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, MalaysiaAbstract: Alpha-lipoic acid, a potent antioxidant with multifarious pharmacological benefits has been reported to be neuroprotective in several neuronal models and used to treat neurological disorders such as Alzheimer’s disease. Nonetheless, conclusive mechanisms of alpha-lipoic acid for its protective effects particularly in NG108-15 cells have never been investigated. In this study, the intricate neuroprotective molecular mechanisms by (R-(+-alpha-lipoic acid (R-LA against H2O2-induced cell death in an in vitro model of neurodegeneration were elucidated. Pretreatment with R-LA (2 hours significantly increased NG108-15 cell viability as compared to H2O2-treated cells and mitigated the induction of apoptosis as evidenced by Hoechst 33342/propidium iodide staining. R-LA (12.5–50 µM aggrandized the reduced glutathione over glutathione disulfide ratio followed by a reduction in the intracellular reactive oxygen species level and an increase in mitochondrial membrane potential following H2O2 exposure. Moreover, pretreatment with R-LA stimulated the activation of PI3K-Akt through mTORC1 and mTORC2 components (mTOR, rictor and raptor and production of antiinflammatory cytokine, IL-10 which led to the inactivation of glycogen synthase kinase-3β (GSK-3β and reduction of both Bax/Bcl2 and Bax/Bcl-xL ratios, accompanied by inhibition of the cleaved caspase-3. Additionally, this observation was preceded by the suppression of NF-κβ p65 translocation and production of proinflammatory cytokines (IL-6 and TNF-α. The current findings accentuate new mechanistic insight of R-LA against apoptogenic and brain inflammatory factors in a neuronal model. These results further advocate the therapeutic potential of R-LA for

  4. 3-(1H-Indol-3-yl-2-(2-nitrobenzenesulfonamidopropanoic acid including an unknown solvate

    Directory of Open Access Journals (Sweden)

    Islam Ullah Khan

    2012-07-01

    Full Text Available In the title compound, C17H15N3O6S, which crystallized with highly disordered methanol and/or water solvent molecules, the dihedral angle between the the indole and benzene ring systems is 5.3 (2°, which allows for the formation of intramolecular π–π stacking interactions [centroid–centroid separations = 3.641 (3 and 3.694 (3 Å] and an approximate overall U-shape for the molecule. In the crystal, dimers linked by pairs of Ns—H...Oc (s = sulfonamide and c = carboxylate hydrogen bonds generate R22(10 loops, whereas Ni—H...π (i = indole interactions lead to chains propagating in [100] or [010]. Together, these lead to a three-dimensional network in which the solvent voids are present as intersecting (two-dimensional systems of [100] and [010] channels. The title compound was found to contain a heavily disordered solvent molecule, which could be methanol or water or a mixture of the two. Due to its uncertain nature and the unresolvable disorder, the data were processed with the SQUEEZE option in PLATON [Spek (2009. Acta Cryst. D65, 148–155], which revealed 877.8 Å3 of solvent-accessible volume per unit cell and 126 electron-units of scattering density or 109.7 Å3 (16 electron units per organic molecule.. This was not included in the calculations of overall formula weight, density and absorption coefficient.

  5. Tellurium sulfates from reactions in oleum and sulfur trioxide: syntheses and crystal structures of TeO(SO_4), Te_4O_3(SO_4)_5, and Te(S_2O_7)_2

    International Nuclear Information System (INIS)

    Logemann, Christian; Bruns, Joern; Schindler, Lisa Verena; Zimmermann, Vanessa; Wickleder, Mathias S.

    2015-01-01

    The reaction of K_2TeO_4 with fuming sulfuric acid (65 % SO_3) in sealed glass ampoules at 250 C led to colorless single crystals of TeO(SO_4) [triclinic, P anti 1, Z = 8, a = 819.89(3) pm, b = 836.95(4) pm, c = 1179.12(5) pm, α = 82.820(2) , β = 70.645(2) , γ = 81.897(2) , V = 753.11(6) x 10"6 pm"3]. A horseshoe type [Te_4O_3] fragment is the basic motif in the layer structure of the compound. The [Te_4O_3] moieties are linked to infinite chains by further oxide ions. Monomeric [Te_4O_3] horseshoes are found in the crystal structure of Te_4O_3(SO_4)_5 [trigonal, P3_221, Z = 3, a = 859.05(2) pm, c = 2230.66(7) pm, V = 1425.61(6) x 10"6 pm"3], which was obtained from TeO_2 and fuming sulfuric acid (65 % SO_3) at 200 C as colorless single crystals. By switching to neat SO_3 as reaction medium colorless crystals of Te(S_2O_7)_2 [P2_1/n, Z = 4, a = 1065.25(3) pm, b = 818.50(2) pm, c = 1206.27(3) pm, β = 102.097(1) , V = 1028.40(5) x 10"6 pm"3] form when ortho-telluric acid, H_6TeO_6, is used as the tellurium source. The compound was reported previously, however, obviously with a wrong crystallographic description. In the crystal structure the tellurium atoms are coordinated by two chelating disulfate ions. Further Te-O contacts link the [Te(S_2O_7)_2] units to an extended network. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Synthesis and structure-activity studies on acidic amino acids and related diacids as NMDA receptor ligands

    DEFF Research Database (Denmark)

    Johansen, T N; Frydenvang, Karla Andrea; Ebert, B

    1994-01-01

    The 3-isoxazolol amino acids (S)-2-amino-3-(3-hydroxy-5-methyl-4- isoxazolyl)propionic acid [(S)-AMPA, 2] and (R,S)-2-amino-2-(3-hydroxy-5-methyl-4-isoxazolyl)acetic acid (AMAA, 5a) (Figure 1) are potent and specific agonists at the AMPA and N-methyl-D-aspartic acid (NMDA) subtypes, respectively......, of (S)-glutamic acid (1) receptors. A number of amino acids and diacids structurally related to AMAA were synthesized and tested electrophysiologically and in receptor-binding assays. The hydroxymethyl analogue 7c of AMAA was an NMDA agonist approximately equipotent with AMAA in the [3H...... by molecular mechanics calculations. Compound 7a possesses extra steric bulk and shows significant restriction of conformational flexibility compared to AMAA and 7c, which may be determining factors for the observed differences in biological activity. Although the nitrogen atom of quinolinic acid (6) has very...

  7. (1S,3S,8R,9S,10R-9,10-Epoxy-3,7,7,10-tetramethyltricyclo[6.4.0.01,3]dodecane

    Directory of Open Access Journals (Sweden)

    Abdoullah Bimoussa

    2014-04-01

    Full Text Available The title compound, C16H26O, was synthesized by treating (1S,3S,8R-3,7,7,10-tetramethyltricyclo[6.4.0.01,3]dodec-9-ene with metachloroperbenzoic acid. The molecule is built up from two fused six- and seven-membered rings. The six-membered ring has a half-chair conformation, whereas the seven-membered ring displays a boat conformation. In the crystal, there are no significant intermolecular interactions present.

  8. Degradation of 3-phenoxybenzoic acid by a Bacillus sp.

    Directory of Open Access Journals (Sweden)

    Shaohua Chen

    Full Text Available 3-Phenoxybenzoic acid (3-PBA is of great environmental concern with regards to endocrine disrupting activity and widespread occurrence in water and soil, yet little is known about microbial degradation in contaminated regions. We report here that a new bacterial strain isolated from soil, designated DG-02, was shown to degrade 95.6% of 50 mg·L(-1 3-PBA within 72 h in mineral salt medium (MSM. Strain DG-02 was identified as Bacillus sp. based on the morphology, physio-biochemical tests and 16S rRNA sequence. The optimum conditions for 3-PBA degradation were determined to be 30.9°C and pH 7.7 using response surface methodology (RSM. The isolate converted 3-PBA to produce 3-(2-methoxyphenoxy benzoic acid, protocatechuate, phenol, and 3,4-dihydroxy phenol, and subsequently transformed these compounds with a q(max, K(s and K(i of 0.8615 h(-1, 626.7842 mg·L(-1 and 6.7586 mg·L(-1, respectively. A novel microbial metabolic pathway for 3-PBA was proposed on the basis of these metabolites. Inoculation of strain DG-02 resulted in a higher degradation rate on 3-PBA than that observed in the non-inoculated soil. Moreover, the degradation process followed the first-order kinetics, and the half-life (t(1/2 for 3-PBA was greatly reduced as compared to the non-inoculated control. This study highlights an important potential application of strain DG-02 for the in situ bioremediation of 3-PBA contaminated environments.

  9. Synthesis and structure of PbBipy2(1-B10H9S(CH3)2)2

    International Nuclear Information System (INIS)

    Orlova, A.M.; Sivaev, I.B.; Lagun, V.L.; Katser, S.B.; Solntsev, K.A.; Kuznetsov, N.T.

    1993-01-01

    Lead complex with B 10 H 9 S(CH 3 ) 2 - anion and 2,2'-bipyridine was synthesized and characterized. According to the data of X-ray diffraction analysis the crystals belong to monoclinic crystal system, sp. gr. P2 1 /a: a = 9.940(4), b 31.568(4), c = 13.458(2) A, β = 111.09(2) deg, V = 3940(2) A 3 , Z = 4. The structure consists of monomer units PbBipy 2 (1-B 10 H 9 S(CH 3 ) 2 ) 2 . The Pb-B distances are within 3.24-3.55 A. 15 refs., 1 fig., 2 tabs

  10. Electrodeposited CuInS2 Using Dodecylbenzene Sulphonic Acid As a Suspending Agent for Thin Film Solar Cell

    Directory of Open Access Journals (Sweden)

    Shaker Ebrahim

    2012-01-01

    Full Text Available CulnS2 thin films were electrochemically deposited onto fluoride-doped tin oxide (FTO substrate in presence of dodecylbenzene sulphonic acid to adjust pH of the solution and as a suspending agent for the sulfur. Cyclic voltammetry and chronoamperometry were carried out to determine the optimum pH. The composition, crystallinity, and optical properties of the compounds synthesized were studied by energy dispersive X-ray (EDX, X-ray diffraction, and UV-Visible spectra. It was found that the increasing of pH shifts the electrodeposited voltage toward more negative and lowers the deposition current. It was concluded that CuInS2 with atomic stoichiometric ratio was prepared at pH equal to 1.5 and 150 ml of 0.1 M sodium thiosulphate, 5 ml of 0.1 M indium chloride, and 5 ml of 0.1 M cupper chloride. The energy gaps were calculated to be 1.95 and 2.2 eV for CuInS2 prepared at 1.5 and 2.5 of pH, respectively. It was found that sc, oc, and are 1.02×10−4 A/cm2, 0.52 V, and 1.3×10−2%, respectively, for FTO/CuInS2/ZnO/FTO heterojunction solar cell.

  11. Nitric Acid and Water Extraction by T2EHDGA in n -Dodecane

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Emily L. [Pacific Northwest National Laboratory, Richland, Washington, USA; Chemistry Department, Washington State University, Pullman, Washington, USA; Holfeltz, Vanessa E. [Pacific Northwest National Laboratory, Richland, Washington, USA; School of Nuclear Science and Engineering, Oregon State University, Corvallis, OR; Hall, Gabriel B. [Pacific Northwest National Laboratory, Richland, Washington, USA; Nash, Kenneth L. [Chemistry Department, Washington State University, Pullman, Washington, USA; Lumetta, Gregg J. [Pacific Northwest National Laboratory, Richland, Washington, USA; Levitskaia, Tatiana G. [Pacific Northwest National Laboratory, Richland, Washington, USA

    2017-11-10

    Liquid-liquid distribution behavior of nitric acid (HNO3) and water by a diglycolamide ligand, N,N,N',N'-tetra-2-ethylhexyldiglycolamide (T2EHDGA) into n-dodecane diluent was investigated. Spectroscopic FTIR and NMR characterization of the organic extraction solutions indicate T2EHDGA carbonyl coordinates HNO3 and progressively aggregates at high acid conditions. Water extraction increases in the presence of HNO3. The experimentally observed distribution of HNO3 was modeled using the computer program, SXLSQI. The results indicated that the formation of two organic phase species—HNO3·T2EHDGA and (HNO3)2·T2EHDGA—satisfactory describes the acid transport behavior. Temperature dependent solvent extraction studies allowed for determination of thermodynamic extraction constants and ΔH and ΔS parameters for the corresponding extractive processes.

  12. Structure of trihydrated rare-earth acid diphosphates LnHP2O7·3H2O (Ln=La, Er)

    International Nuclear Information System (INIS)

    Ben Moussa, S.; Ventemillas, S.; Cabeza, A.; Gutierrez-Puebla, E.; Sanz, J.

    2004-01-01

    In trihydrated lanthanum acid-diphosphates LnHP 2 O 7 ·3H 2 O, prepared from acid LnCl 3 and Na 4 P 2 O 7 solutions (pH=1), two crystal forms were obtained. Layered structures of two representative members of this family have been determined by single-crystal X-ray diffraction (XRD) technique. In the case of orthorhombic LaHP 2 O 7 ·3H 2 O (type I), lanthanum cations are ninefold coordinated and diphosphate groups adopt a staggered (alternated) configuration. In the case of triclinic ErHP 2 O 7 ·3H 2 O (type II), erbium cations are eightfold coordinated and diphosphate groups adopt an eclipsed configuration. In agreement with Infrared (IR) spectroscopic data, a bended configuration for diphosphate groups has been deduced. In both structures, one-dimensional chains of edge-sharing rare-earth polyhedra are linked together by diphosphate groups to form the phosphate layers. In both diphosphates, PO 4 and HPO 4 environments have been identified by 31 P MAS-NMR technique. In the two compounds, OH groups of HPO 4 tetrahedra point out of diphosphate planes interacting with adjacent layers. In La-diphosphate, the interaction between HPO 4 groups and water molecules of adjacent layers is favored; however, in Er-diphosphate, the interaction between phosphate acid groups of contiguous layers is produced. Based on structural information deduced, differences detected in IR and NMR spectra of two disphosphates are discussed

  13. Synthesis and Characterisation of Tris(1-carboxyl-2-phenyl-1,2-ethyl eno dithiol enic-S,S') Tungsten Complex as Photo catalyst for Photolysis of H2O Molecules

    International Nuclear Information System (INIS)

    Fadhli Hadana Rahman; Rusli Daik; Mohammad Kassim; Khuzaimah; Wan Ramli Wan Daud

    2008-01-01

    Tris(1-carboxyl-2-phenyl-1,2-ethylenodithiolenic-S,S ' ) tungsten complex is one of the most promising photo catalyst to be used in photolysis of water to produce hydrogen. The first step of the synthesis involves a metathesis reaction of tetrapropylammonium bromide [((C 3 H 7 ) 4 N)Br] and ammonium tetrathiotungstate [(NH 4 ) 2 WS 4 ] to form a tetrapropylammonium tetrathiotungstate [((C 3 H 7 ) 4 N) 2 WS 4 ] (precursor). Then, the precursor was reacted with phenyl acetylenecarboxylic acid (C 9 H 6 O 2 ) to form tris(1-carboxyl-2-phenyl-1,2-ethylenodithiolenic-S,S ' ) tungsten complex (C 27 H 18 O 2 S 6 W). The infra-red, ultra violet/ visible (UV/ Vis) spectrum, nuclear magnetic resonance (NMR) and elemental micro-analysis of C, H, N and S agreed with the characteristic of the tris(1-carboxyl-2-phenyl-1,2-ethylenodithiolenic-S,S ' ) tungsten complex. The (W-S), (C-S) and (C=O) stretching frequencies were detected at 511, (1470 and 1035) and 1655 cm -1 , respectively. The 1 H NMR spectrum showed six protons in the complex. The 13 C NMR showed only 7 signals for carbon atom in the benzene ring, ethylene groups and carboxylic acid pendant group due to the symmetry of the molecules. The reaction yield was about 50 percent. Photolysis of acetone spiked H 2 O showed that the catalyst was able to produced 1.8 μmol/ h hydrogen. (author)

  14. Phenylpropanoid 2,3-dioxygenase involved in the cleavage of the ferulic acid side chain to form vanillin and glyoxylic acid in Vanilla planifolia.

    Science.gov (United States)

    Negishi, Osamu; Negishi, Yukiko

    2017-09-01

    Enzyme catalyzing the cleavage of the phenylpropanoid side chain was partially purified by ion exchange and gel filtration column chromatography after (NH 4 ) 2 SO 4 precipitation. Enzyme activities were dependent on the concentration of dithiothreitol (DTT) or glutathione (GSH) and activated by addition of 0.5 mM Fe 2+ . Enzyme activity for ferulic acid was as high as for 4-coumaric acid in the presence of GSH, suggesting that GSH acts as an endogenous reductant in vanillin biosynthesis. Analyses of the enzymatic reaction products with quantitative NMR (qNMR) indicated that an amount of glyoxylic acid (GA) proportional to vanillin was released from ferulic acid by the enzymatic reaction. These results suggest that phenylpropanoid 2,3-dioxygenase is involved in the cleavage of the ferulic acid side chain to form vanillin and GA in Vanilla planifolia.

  15. Biotransformation of 2,3,3,3-tetrafluoropropene (HFO-1234yf)

    International Nuclear Information System (INIS)

    Schuster, Paul; Bertermann, Ruediger; Snow, Timothy A.; Han Xing; Rusch, George M.; Jepson, Gary W.; Dekant, Wolfgang

    2008-01-01

    2,3,3,3-Tetrafluoropropene (HFO-1234yf) is a non-ozone-depleting fluorocarbon replacement with a low global warming potential which has been developed as refrigerant. The biotransformation of HFO-1234yf was investigated after inhalation exposure. Male Sprague-Dawley rats were exposed to air containing 2000, 10,000, or 50,000 ppm HFO-1234yf for 6 h and male B6C3F1 mice were exposed to 50,000 ppm HFO-1234yf for 3.5 h in a dynamic exposure chamber (n = 5/concentration). After the end of the exposure, animals were individually housed in metabolic cages and urines were collected at 6 or 12-hour intervals for 48 h. For metabolite identification, urine samples were analyzed by 1 H-coupled and decoupled 19 F-NMR and by LC/MS-MS or GC/MS. Metabolites were identified by 19 F-NMR chemical shifts, signal multiplicity, 1 H- 19 F coupling constants and by comparison with synthetic reference compounds. In all urine samples, the predominant metabolites were two diastereomers of N-acetyl-S-(3,3,3-trifluoro-2-hydroxy-propyl)-L-cysteine. In 19 F-NMR, the signal intensity of these metabolites represented more than 85% (50,000 ppm) of total 19 F related signals in the urine samples. Trifluoroacetic acid, 3,3,3-trifluorolactic acid, 3,3,3-trifluoro-1-hydroxyacetone, 3,3,3-trifluoroacetone and 3,3,3-trifluoro-1,2-dihydroxypropane were present as minor metabolites. Quantification of N-acetyl-S-(3,3,3-trifluoro-2-hydroxy-propyl)-L-cysteine by LC/MS-MS showed that most of this metabolite (90%) was excreted within 18 h after the end of exposure (t 1/2 app. 6 h). In rats, the recovery of N-acetyl-S-(3,3,3-trifluoro-2-hydroxy-propyl)-L-cysteine excreted within 48 h in urine was determined as 0.30 ± 0.03, 0.63 ± 0.16, and 2.43 ± 0.86 μmol at 2000, 10,000 and 50,000 ppm, respectively suggesting only a low extent (<< 1% of dose received) of biotransformation of HFO-1234yf. In mice, the recovery of this metabolite was 1.774 ± 0.4 μmol. Metabolites identified after in vitro incubations of HFO

  16. A novel ascorbic acid sensor based on the Fe3+/Fe2+ modulated photoluminescence of CdTe quantum dots@SiO2 nanobeads.

    Science.gov (United States)

    Ma, Qiang; Li, Yang; Lin, Zi-Han; Tang, Guangchao; Su, Xing-Guang

    2013-10-21

    In this paper, CdTe quantum dot (QD)@silica nanobeads were used as modulated photoluminescence (PL) sensors for the sensing of ascorbic acid in aqueous solution for the first time. The sensor was developed based on the different quenching effects of Fe(2+) and Fe(3+) on the PL intensity of the CdTe QD@ silica nanobeads. Firstly, the PL intensity of the CdTe QDs was quenched in the presence of Fe(3+). Although both Fe(2+) and Fe(3+) could quench the PL intensity of the CdTe QDs, the quenching efficiency were quite different for Fe(2+) and Fe(3+). The PL intensity of the CdTe QD@silica nanobeads can be quenched by about 15% after the addition of Fe(3+) (60 μmol L(-1)), while the PL intensity of the CdTe QD@silica nanobeads can be quenched about 49% after the addition of Fe(2+) (60 μmol L(-1)). Therefore, the PL intensity of the CdTe QD@silica nanobeads decreased significantly when Fe(3+) was reduced to Fe(2+) by ascorbic acid. To confirm the strategy of PL modulation in this sensing system, trace H2O2 was introduced to oxidize Fe(2+) to Fe(3+). As a result, the PL intensity of the CdTe QD@silica nanobeads was partly recovered. The proposed sensor could be used for ascorbic acid sensing in the concentration range of 3.33-400 μmol L(-1), with a detection limit (3σ) of 1.25 μmol L(-1) The feasibility of the proposed sensor for ascorbic acid determination in tablet samples was also studied, and satisfactory results were obtained.

  17. [Composition diversity of lactic acid bacteria (LAB) community Al2 used for alfalfa silage].

    Science.gov (United States)

    Wang, Xiao-Fen; Gao, Li-Juan; Yang, Hong-Yan; Wang, Wei-Dong; Cui, Zong-Jun

    2006-10-01

    Alfalfa is the most important forage grass that is difficult to ensile for good quality. Using silage inoculants are the important way for preservation of alfalfa silage. Through continuous restricted subcultivation, a lactic acid bacteria (LAB) community Al2 was selected from well-fermented alfalfa silage. Plate isolation and Denaturing Gradient Gel Electrophoresis (DGGE), construction of 16S rDNA clone library were used to identify the composition diversity of Al2 community, with 7 strains detected, and they were all belonged to Lactobacillus. The composition ratios of the 7 strains were 55.21%, 19.79%, 14.58%, 3.13%, 3.13%, 3.13%, 1.03% according to 16S rDNA clone library. Al2-1i, Al2-2i, Al2-3i, corresponding to L. plantarum (99.9%), L. kimchii (99.4%), L. farciminis (100%) were detected by plate isolation. Among 3 isolates, Al2-1i had the highest ability of dropping pH and producing lactic acid, and the amount of lactic acid was reach to 18g/L at 24h cultivated in MRS media. The ability of dropping pH and producing lactic acid of Al2-3i was the lowest. From DGGE profiles, the dominant strains in Al2 community were L. plantarum and L. kimchii. L. plantarum was detected during the whole process, and L. kimchii was detected in the later phase.

  18. Acid-deposition research program. Volume 2. Effects of acid-forming emissions on soil microorganisms and microbially-mediated processes

    Energy Technology Data Exchange (ETDEWEB)

    Visser, S.; Danielson, R.M.; Parr, J.F.

    1987-02-01

    The interactions of soil physical, chemical, and biological processes are ultimately expressed in a soil's fertility and its capacity for plant production. Consequently, much of the research conducted to date regarding the impact of acid-forming pollutants on soil properties has been geared towards possible effects on plant productivity. This trend continues in this paper where the effects of acidic deposition on microbial communities are reviewed in relation to potential impact on plant growth. The objectives of the review are to discuss: (1) The effects of acid-forming emissions (primarily S-containing pollutants) on microbial community structure with emphasis on qualitative and quantitative aspects; (2) The effects of acidic deposition on microbially mediated processes (i.e., community functions); (3) Acidification effects of pollutants on symbiotic and disease-causing microorganisms. The symbionts discussed include ectomycorrhizal fungi, vesicular-arbuscular mycorrhizal fungi, and N/sub 2/-fixing bacteria, particularly Rhizobium, while the disease-causing microorganisms will include those responsible for foliage, stem, and root diseases.

  19. 2-Aminobenzoic acid–4-(pyridin-4-yldisulfanyl)pyridine (1/1)

    OpenAIRE

    Hadi D. Arman; Trupta Kaulgud; Edward R. T. Tiekink

    2011-01-01

    The title 1:1 co-crystal, C7H7NO2·C10H8N2S2, features a highly twisted 4-(pyridin-4-yldisulfanyl)pyridine molecule [dihedral angle between the pyridine rings = 89.06 (10)°]. A small twist is evident in the 2-aminobenzoic acid molecule, with the C—C—C—O torsion angle being −7.7 (3)°. An N—H...O hydrogen bond occurs in the 2-aminobenzoic acid molecule. In the crystal, molecules are linked by O&#...

  20. Efficacy of In2S3 interfacial recombination barrier layer in PbS quantum-dot-sensitized solar cells

    International Nuclear Information System (INIS)

    Basit, Muhammad Abdul; Abbas, Muhammad Awais; Bang, Jin Ho; Park, Tae Joo

    2015-01-01

    In 2 S 3 interfacial recombination barrier layer (IBL) via successive ionic layer adsorption and reaction (SILAR) was successfully employed between PbS quantum dots and mesoporous TiO 2 in quantum-dot-sensitized solar cells (QDSSCs). In 2 S 3 IBL significantly increased the resistance against back electron transfer from TiO 2 , resulting an increment in the photocurrent density (J SC ) for the cell with single SILAR cycle of In 2 S 3 IBL. Further increase in the number of SILAR cycles of In 2 S 3 IBL deteriorated the J SC , whereas open-circuit voltage sustained the increasing trend. Therefore, an optimal photo-conversion efficiency of ∼2.2% was obtained for the cell with 2 SILAR cycles of In 2 S 3 IBL, which strategically reached a value of ∼2.70% after annealing (increased by 40% compared to the control cell without IBL). In 2 S 3 IBL not only improved the recombination resistance and electron life time of the cells, but it also enhanced the photostability of the cells. - Highlights: • In 2 S 3 interfacial recombination barrier layer was deposited on TiO 2 photoanode via SILAR process. • Resistance against back electron transfer from TiO 2 (recombination) increased notably. • Fabricated PbS-QDSSCs were characterized using IPCE, OCVD and EIS techniques. • In 2 S 3 IBL improved chemical capacitance, electron life time and photostability of modified cells. • 2In 2 S 3 IBL showed optimal performance, yielding 40% improvement in PCE after heat treatment.

  1. Near-threshold electron-impact excitation of the (2p53s2)2P3/2,1/2 autoionizing states in sodium

    International Nuclear Information System (INIS)

    Borovik, A; Zatsarinny, O; Bartschat, K

    2008-01-01

    The ejected-electron excitation functions of the J = 3/2, 1/2 components of the (2p 5 3s 2 ) 2 P leading autoionizing doublet in sodium atoms were measured at an incident electron energy resolution of 0.25 eV over the incident electron energy range from the lowest excitation threshold up to 36 eV. On the basis of 56-state R-matrix (close-coupling) calculations, the observed strong near-threshold structures were classified as negative-ion resonances with likely configurations 2p 5 3s 2 3p and 2p 5 3s3p 2

  2. 40 CFR 721.5252 - 2-Naphthalenecarboxylic acid, 4,4′-methylenebis [3-hydroxy-, zinc salt.

    Science.gov (United States)

    2010-07-01

    ...-methylenebis [3-hydroxy-, zinc salt. 721.5252 Section 721.5252 Protection of Environment ENVIRONMENTAL...′-methylenebis [3-hydroxy-, zinc salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 2-Naphthalenecarboxylic acid, 4,4′-methylenebis [3-hydroxy-, zinc...

  3. Switchable Synthesis of 4,5-Functionalized 1,2,3-Thiadiazoles and 1,2,3-Triazoles from 2-Cyanothioacetamides under Diazo Group Transfer Conditions.

    Science.gov (United States)

    Filimonov, Valeriy O; Dianova, Lidia N; Galata, Kristina A; Beryozkina, Tetyana V; Novikov, Mikhail S; Berseneva, Vera S; Eltsov, Oleg S; Lebedev, Albert T; Slepukhin, Pavel A; Bakulev, Vasiliy A

    2017-04-21

    High yield solvent-base-controlled, transition metal-free synthesis of 4,5-functionalized 1,2,3-thiadiazoles and 1,2,3-triazoles from 2-cyanothioacetamides and sulfonyl azides is described. Under diazo transfer conditions in the presence of a base in an aprotic solvent 2-cyanothioacetamides operating as C-C-S building blocks produce 5-amino-4-cyano-1,2,3-thiadiazoles exclusively. The use of alkoxide/alcohol system completely switches the reaction course due to the change of one of the reaction centers in the 2-cyanothioacetamide (C-C-N building block) resulting in the formation of 5-sulfonamido-1,2,3-triazole-4-carbothioamide sodium salts as the only products. The latter serve as good precursors for 5-amino-1,2,3-thiadiazole-4-carboximidamides, the products of Cornforth-type rearrangement occurring in neutral protic medium or under acid conditions. According to DFT calculations (B3LYP/6-311+G(d,p)) the rearrangement proceeds via intermediate formation of a diazo compound, and can be catalyzed by acids via the protonation of oxygen atom of the sulfonamide group.

  4. Construction of Eu3+ Ion-Selective Electrode Based on 1,2-Diaminopropane-N,N,N',N'-tetraacetic acid

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Abedi

    2011-01-01

    Full Text Available A new Eu3+ PVC membrane electrode based on 1,2-diaminopropane-N, N,N',N'-tetraacetic acid (DAPTA as a suitable ionophore has been prepared and studied. The electrode shows a good selectivity for Eu(III ion with respect to most common cations including alkali, alkaline earth, transition and heavy metal ions. This electrode has a wide linear dynamic range from 1.0×10-6 to 1.0×10-2 M with a Nernstian slope of 19.7±0.5 mV per decade and a low detection limit of 7.2×10-7 M in the pH range of 2.5–9.1, while the response time was rapid (<10 s. The practical utility of the electrodes has been demonstratedby their use as indicator electrodes in the potentiometric titration of Eu3+ ions with EDTA and for the determination of Eu3+ in some water sample solutions.

  5. Folic Acid Reduces Tau Phosphorylation by Regulating PP2A Methylation in Streptozotocin-Induced Diabetic Mice

    Science.gov (United States)

    Zheng, Miaoyan; Zou, Chen; Li, Mengyue; Huang, Guowei; Gao, Yuxia; Liu, Huan

    2017-01-01

    High incidence rate of Alzheimer’s disease (AD) is observed in patients with type 2 diabetes. Aggregated β-amyloid (Aβ) and hyperphosphorylated tau are the hallmarks of AD. Hyperphosphorylated tau has been detected in diabetic animals as well as in diabetic patients. Folates mediate the transfer of one carbon unit, required in various biochemical reactions. The effect of folate on tau phosphorylation in diabetic models still remains unknown. In this study, we investigated the effect and mechanism of folic acid on hyperphosphorylation of tau in streptozotocin (STZ)-induced diabetic mice. Diabetic mice induced by STZ, at the age of 10 weeks, were administered with three levels of folic acid: folic acid-deficient diet, diet with normal folic acid content, and 120 μg/kg folic acid diet for 8 weeks. Levels of serum folate and blood glucose were monitored. Tau phosphorylation, protein phosphatase 2A (PP2A) methylation, and Glycogen synthase kinase 3β (GSK-3β) phosphorylation were detected using Western blot. The S-adenosyl methionine:S-adenosyl homocysteine ratio (SAM:SAH) in brain tissues was also determined. DNA methyltransferase (DNMT) mRNA expression levels were detected using real-time PCR. Folic acid reduced tau hyperphosphorylation at Ser396 in the brain of diabetes mellitus (DM) mice. In addition, PP2A methylation and DNMT1 mRNA expression were significantly increased in DM mice post folic acid treatment. GSK-3β phosphorylation was not regulated by folic acid administration. Folic acid can reduce tau phosphorylation by regulating PP2A methylation in diabetic mice. These results support that folic acid can serve as a multitarget neuronal therapeutic agent for treating diabetes-associated cognitive dysfunction. PMID:28422052

  6. Carbon-free H2 production from ammonia triggered at room temperature with an acidic RuO2/γ-Al2O3 catalyst.

    Science.gov (United States)

    Nagaoka, Katsutoshi; Eboshi, Takaaki; Takeishi, Yuma; Tasaki, Ryo; Honda, Kyoko; Imamura, Kazuya; Sato, Katsutoshi

    2017-04-01

    Ammonia has been suggested as a carbon-free hydrogen source, but a convenient method for producing hydrogen from ammonia with rapid initiation has not been developed. Ideally, this method would require no external energy input. We demonstrate hydrogen production by exposing ammonia and O 2 at room temperature to an acidic RuO 2 /γ-Al 2 O 3 catalyst. Because adsorption of ammonia onto the catalyst is exothermic, the catalyst bed is rapidly heated to the catalytic ammonia autoignition temperature, and subsequent oxidative decomposition of ammonia produces hydrogen. A differential calorimeter combined with a volumetric gas adsorption analyzer revealed a large quantity of heat evolved both with chemisorption of ammonia onto RuO 2 and acidic sites on the γ-Al 2 O 3 and with physisorption of multiple ammonia molecules.

  7. Group I mGlu receptors potentiate synaptosomal [3H]glutamate release independently of exogenously applied arachidonic acid

    International Nuclear Information System (INIS)

    Reid, M.E.; Toms, N.J.; Bedingfield, J.S.; Roberts, P.J.

    1999-01-01

    In the current study, we have characterized group I metabotropic glutamate (mGlu) receptor enhancement of 4-aminopyridine (4AP)-evoked [ 3 H]glutamate release from rat cerebrocortical synaptosomes. The broad spectrum mGlu receptor agonist (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid ((1S,3R)-ACPD, 10 μM) increased 4AP-evoked [ 3 H]glutamate release (143.32±2.73% control) only in the presence of exogenously applied arachidonic acid; an effect reversed by the inclusion of bovine serum albumin (BSA, fatty acid free). In contrast, the selective group I mGlu receptor agonist (S)-3,5-dihydroxyphenylglycine (DHPG) potentiated (EC 50 =1.60±0.25 μM; E max =147.61±10.96% control) 4AP-evoked [ 3 H]glutamate release, in the absence of arachidonic acid. This potentiation could be abolished by either the selective mGlu 1 receptor antagonist (R,S)-1-aminoindan-1,5-dicarboxylic acid (AIDA, 1 mM) or the selective PKC inhibitor (Ro 31-8220, 10 μM) and was BSA-insensitive. The selective mGlu 5 receptor agonist (R,S)-2-chloro-5-hydroxyphenylglycine (CHPG, 300μM) was without effect. DHPG (100 μM) also potentiated both 30 mM and 50 mM K + -evoked [ 3 H]glutamate release (121.60±12.77% and 121.50±4.45% control, respectively). DHPG (100 μM) failed to influence both 4AP-stimulated 45 Ca 2+ influx and 50 mM K + -induced changes in synaptosomal membrane potential. Possible group I mGlu receptor suppression of tonic adenosine A 1 receptor, group II/III mGlu receptors or GABA B receptor activity is unlikely since 4AP-evoked [ 3 H]glutamate release was insensitive to the selective inhibitory receptor antagonists 8-cyclopentyl-1,3-dimethylxanthine, (R,S)-α-cyclopropyl-4-phosphonophenylglycine or CGP55845A, respectively. These data suggest an 'mGlu 1 receptor-like' receptor potentiates [ 3 H]glutamate release from cerebrocortical synaptosomes in the absence of exogenously applied arachidonic acid. This PKC dependent effect is unlikely to be via modulation of synaptosomal membrane

  8. Stereoselective synthesis of functionalized cyclic amino acid derivatives via a [2,3]-Stevens rearrangement and ring-closing metathesis.

    Science.gov (United States)

    Nash, Aaron; Soheili, Arash; Tambar, Uttam K

    2013-09-20

    Unnatural cyclic amino acids are valuable tools in biomedical research and drug discovery. A two-step stereoselective strategy for converting simple glycine-derived aminoesters into unnatural cyclic amino acid derivatives has been developed. The process includes a palladium-catalyzed tandem allylic amination/[2,3]-Stevens rearrangement followed by a ruthenium-catalyzed ring-closing metathesis. The [2,3]-rearrangement proceeds with high diastereoselectivity through an exo transition state. Oppolzer's chiral auxiliary was utilized to access an enantiopure cyclic amino acid by this approach, which will enable future biological applications.

  9. Measurement of the Absolute Raman Cross Sections of Diethyl Phthalate, Dimethyl Phthalate, Ethyl Cinnamate, Propylene Carbonate, Tripropyl Phosphate, 1,3-Cyclohexanedione, 3’-Aminoacetophenone, 3’-Hydroxyacetophenone, Diethyl Acetamidomalonate, Isovanillin, Lactide, Meldrum’s Acid, p-Tolyl Sulfoxide, and Vanillin

    Science.gov (United States)

    2013-09-13

    Lactide, Meldrum’s Acid , p-Tolyl Sulfoxide, and Vanillin R.L. Aggarwal L.W. Farrar B.G. Saar T.H. Jeys R.B. Goodman 13 September 2013...Aminoacetophenone, 3’-Hydroxyacetophenone, Diethyl Acetamidomalonate, Isovanillin, Lactide, Meldrum’s Acid , p-Tolyl Sulfoxide, and Vanillin R.L...hydroxyacetophenone (HOAP), diethyl acetamidomalonate (DEAM), isovanillin (ISOV), lactide (DODO), Meldrum’s acid (MA), p-tolyl sulfoxide (PTSO), and vanillin

  10. SL(2, Z) invariant rotating (m, n) strings in AdS{sub 3} x S{sup 3} with mixed flux

    Energy Technology Data Exchange (ETDEWEB)

    Barik, M.S.P.; Panigrahi, Kamal L. [Indian Institute of Technology Kharagpur, Department of Physics, Kharagpur (India); Khouchen, Malak; Kluson, Josef [Masaryk University, Department of Theoretical Physics and Astrophysics, Faculty of Science, Brno (Czech Republic)

    2017-05-15

    We study rigidly rotating and pulsating (m, n) strings in AdS{sub 3} x S{sup 3} with mixed three form flux. The AdS{sub 3} x S{sup 3} background with mixed three form flux is obtained in the near horizon limit of SL(2, Z)-transformed solution, corresponding to the bound state of NS5-branes and fundamental strings. We study the probe (m, n)-string in this background by solving the manifest SL(2, Z)-covariant form of the action. We find the dyonic giant magnon and single spike solutions corresponding to the equations of motion of a probe string in this background and find various relationships among the conserved charges. We further study a class of pulsating (m, n) string in AdS{sub 3} with mixed three form flux. (orig.)

  11. Isoelectronic comparison of the Al-like 3s23p 2P-3s3p24P transitions in the ions P III-Mo XXX

    International Nuclear Information System (INIS)

    Jupen, C.; Curtis, L.J.

    1996-01-01

    New observations of the 3s 2 3p 2 P-3s3p 2 4 P intercombination transitions in Al-like ions have been made for Cl V from spark spectra recorded at Lund and for Kr XXIV and Mo XXX from spectra obtained at the JET tokamak. The new results have been combined with other identifications of these transitions along the sequence and empirically systematized and compared with theoretical calculations. A set of smoothed and interpolated values for the excitation energies of the 3s3p 2 4 P levels in P III-Mo XXX is presented. (orig.)

  12. Inactivation of the glutamine/amino acid transporter ASCT2 by 1,2,3-dithiazoles: proteoliposomes as a tool to gain insights in the molecular mechanism of action and of antitumor activity

    Energy Technology Data Exchange (ETDEWEB)

    Oppedisano, Francesca [Dipartimento di Biologia Cellulare Università della Calabria, via P. Bucci 4 c, 87036 Arcavacata di Rende (CS) (Italy); Catto, Marco [Dipartimento Farmaco-Chimico, Università degli Studi “Aldo Moro,”, via Orabona 4, 70125 Bari (Italy); Koutentis, Panayiotis A. [Department of Chemistry, University of Cyprus, P.O. Box 20537, 1678 Nicosia (Cyprus); Nicolotti, Orazio [Dipartimento Farmaco-Chimico, Università degli Studi “Aldo Moro,”, via Orabona 4, 70125 Bari (Italy); Pochini, Lorena [Dipartimento di Biologia Cellulare Università della Calabria, via P. Bucci 4 c, 87036 Arcavacata di Rende (CS) (Italy); Koyioni, Maria [Department of Chemistry, University of Cyprus, P.O. Box 20537, 1678 Nicosia (Cyprus); Introcaso, Antonellina [Dipartimento Farmaco-Chimico, Università degli Studi “Aldo Moro,”, via Orabona 4, 70125 Bari (Italy); Michaelidou, Sophia S. [Department of Chemistry, University of Cyprus, P.O. Box 20537, 1678 Nicosia (Cyprus); Carotti, Angelo, E-mail: carotti@farmchim.uniba.it [Dipartimento Farmaco-Chimico, Università degli Studi “Aldo Moro,”, via Orabona 4, 70125 Bari (Italy); Indiveri, Cesare, E-mail: indiveri@unical.it [Dipartimento di Biologia Cellulare Università della Calabria, via P. Bucci 4 c, 87036 Arcavacata di Rende (CS) (Italy)

    2012-11-15

    The ASCT2 transport system catalyses a sodium-dependent antiport of glutamine and other neutral amino acids which is involved in amino acid metabolism. A library of 1,2,3-dithiazoles was designed, synthesized and evaluated as inhibitors of the glutamine/amino acid ASCT2 transporter in the model system of proteoliposomes reconstituted with the rat liver transporter. Fifteen of the tested compounds at concentration of 20 μM or below, inhibited more than 50% the glutamine/glutamine antiport catalysed by the reconstituted transporter. These good inhibitors bear a phenyl ring with electron withdrawing substituents. The inhibition was reversed by 1,4-dithioerythritol indicating that the effect was likely owed to the formation of mixed sulfides with the protein's Cys residue(s). A dose–response analysis of the most active compounds gave IC{sub 50} values in the range of 3–30 μM. Kinetic inhibition studies indicated a non-competitive inhibition, presumably because of a potential covalent interaction of the dithiazoles with cysteine thiol groups that are not located at the substrate binding site. Indeed, computational studies using a homology structural model of ASCT2 transporter, suggested as possible binding targets, Cys-207 or Cys-210, that belong to the CXXC motif of the protein. -- Highlights: ► Non‐competitive inhibition of ASCT2 by 1,2,3-dithiazoles was studied in proteoliposomes. ► Different 1,2,3-dithiazoles were synthesized and evaluated as transporter inhibitors. ► Many compounds potently inhibited the glutamine/glutamine antiport catalyzed by ASCT2. ► The inhibition was reversed by DTE indicating reaction with protein Cys. ► The most active compounds gave IC{sub 50} in the range of 3–30 μM.

  13. A Study of Acid-Base Equilibria in Acetonitrile Systems of 2-Halo(Cl,Br,I-4-nitropicoline(3,5,6 N-oxides

    Directory of Open Access Journals (Sweden)

    Lech Chmurzynski

    1999-03-01

    Full Text Available An attempt has been made to determine potentiometrically (1 acid dissociation constants of cations obtained by protonation of nine trisubstituted pyridine N-oxides, namely 2-halo(Cl, Br and I-4-nitropicoline N-oxides with the methyl group at positions 3, 5, and 6, as well as (2 the cationic homoconjugation constants of these cationic acids with conjugated N-oxides in acetonitrile. On the basis of the substitution effect, variations of the acid dissociation constants of the trisubstituted pyridine N-oxide cations are discussed. The determined pKa values of the protonated 2-halo-4-nitropicoline N-oxides are compared with the previously determined equilibrium constants of the cationic acids conjugated with the mono- and disubstituted pyridine N-oxides in acetonitrile. Further, based on the pKa values of the protonated 2-halo-4-nitropicoline N-oxides in acetonitrile, supplemented with correlations between pKa’s of the protonated mono- and disubstituted pyridine N-oxides in acetonitrile and water, the pKa's of the acids conjugated with the trisubstituted N-oxides studied in aqueous solutions have been estimated. Moreover, it has been concluded that the cationic homoconjugation constants cannot be determined by potentiometric titration in acetonitrile solutions of the 2-halo-4-nitropicoline N-oxide systems.

  14. Electrochemiluminescent graphene quantum dots enhanced by MoS2 as sensing platform: a novel molecularly imprinted electrochemiluminescence sensor for 2-methyl-4-chlorophenoxyacetic acid assay

    International Nuclear Information System (INIS)

    Yang, Yukun; Fang, Guozhen; Wang, Xiaomin; Zhang, Fuyuan; Liu, Jingmin; Zheng, Wenjie; Wang, Shuo

    2017-01-01

    Highlights: • Electrochemiluminescent MoS 2 -GQDs nanocomposite was fabricated for the first time. • MoS 2 -GQDs hybrid nanocomposite was used as ECL sensing platform. • Molecularly imprinted ECL sensor was fabricated for the determination of MCPA. • MoS 2 -GQDs nanocomposite may advance the developments of ECL sensor. - Abstract: The ECL properties and application of a novel luminescent material molybdenum disulfide-graphene quantum dots (MoS 2 -GQDs) hybrid nanocomposite was reported for the first time. The hybridization of MoS 2 and GQDs endowed nanocomposite with structural and compositional advantages for boosting the ECL performance of GQDs. Impressively, the ECL could be remarkable enhanced using MoS 2 -GQDs hybrid nanocomposite, which was ∼13, ∼185 and ∼596-folds larger than the ECL intensity of GQDs, MoS 2 modified electrodes and bare electrode, respectively. Subsequently, as a sensing platform, the MoS 2 -GQDs hybrid nanocomposite was applied to fabricate molecularly imprinted electrochemiluminescence sensor for the ultrasensitive and selective determination of 2-methyl-4-chlorophenoxyacetic acid. Under optimal conditions, the detection limit of the prepared sensor was 5.5 pmol L −1 (S/N = 3) within a linear concentration range of 10 pmol L −1 –0.1 μmol L −1 . The developped sensor exhibited high sensitivity, good selectivity, reproducibility and stability, suggesting the potential for detecting pesticides and veterinary drugs at trace levels in food safety and environmental control.

  15. Differential expression of fatty acid uptake in 3T3-L1 cells

    International Nuclear Information System (INIS)

    Waggoner, D.; Bernlohr, D.A.

    1987-01-01

    Cultured 3T3-L1 cells have been used as a model system to investigate the mechanism of fatty acid uptake by adipose tissue. Using a 1:1 molar ratio of 14 C-oleate and defatted bovine serum albumin (BSA), fatty acid (FA) uptake was quantitated at 4 0 and 37 0 as cell associated radioactivity. The profile of FA uptake in preadipocytes and adipocytes was biphasic; an initial rapid phase (1-20s) followed by a second slower phase (60-480s). At 37 0 the initial rate of FA accumulation in preadipocytes was identical to that in adipocytes, whereas the rate of accumulation during the second phase increased 7-fold (100 μM total FA) as a consequence of adipose conversion. When uptake measurements were made at 4 0 in adipocytes, the initial rate was identical to that at 37 0 , however the rate of second phase decreased 5-fold. Incubation of 14 C-BSA and nonradiolabeled FA with adipocyte monolayers (100 μM total FA) resulted in the rapid association (t/sub 1/2/ = 20s) of the BSA-FA complex with the cell surface. Incubation of 100, 10, and 1 μM total FA with adipocytes resulted in a 50-fold change in FA accumulation during the second phase. These results suggest that (1) FA uptake is significantly increased after differentiation, suggesting the participation of specialized proteins, (2) the temperature-insensitive initial FA accumulation can be attributed to rapid association of the BSA-FA complex to the cell surface, (3) the second phase of FA accumulation represents uptake

  16. A Concise Synthesis and the Antibacterial Activity of 5,6-Dimethoxynaphthalene-2-carboxylic Acid

    OpenAIRE

    GÖKSU, Süleyman; UĞUZ, Metin Tansu

    2014-01-01

    5,6-Dimethoxynaphthalene-2-carboxylic acid was synthesized in 7 steps and with an overall yield of 46%. Bromination of 2-naphthol, and methylation with dimethyl sulfate followed by Friedel-Crafts acylation with AcCl gave 2-acetyl-5-bromo-6-methoxynaphthalene. 2-Acetyl-5-bromo-6-methoxynaphthalene was converted to 5-bromo-6- methoxynaphthalene-2-carboxylic acid by a haloform reaction. The esterification of the acid with methanol, methoxylation with NaOCH3 in the presence of CuI and s...

  17. Long lasting behavior of Gd2O2S:Eu3+ phosphor synthesized by hydrothermal routine

    International Nuclear Information System (INIS)

    Hang Tao; Liu Qun; Mao Dali; Chang Chengkang

    2008-01-01

    This paper reports the detailed preparation process and afterglow properties of Eu 3+ activated long lasting Gd 2 O 2 S phosphor by hydrothermal routine. Rod-like Gd(OH) 3 were firstly synthesized by hydrothermal method to serve as the precursor. Long lasting Gd 2 O 2 S:Eu 3+ ,Ti 4+ ,Mg 2+ phosphor was obtained by calcinating the precursor with co-activators and S powder. It was found from the results that the hydrothermally prepared Gd(OH) 3 revealed a rod-like morphology, while the calcinated Gd 2 O 2 S:Eu 3+ ,Ti 4+ ,Mg 2+ phosphor showed a round granular shape. The morphological change can be explained by the etching effect of the melt that was formed by the carbonate and S powder during the high temperature calcination. The obtained Gd 2 O 2 S:Eu 3+ ,Ti 4+ ,Mg 2+ phosphor produced a red emission upon 243 nm UV excitation, which is a typical emission of Eu 3+ from 5 D j to 7 F j states. Long lasting behavior was observed after the UV source was switched off, due to the formation of electron traps with suitable trap depth within the matrix by the codoped Ti 4+ and Mg 2+ ions

  18. Flexible camphor sulfonic acid-doped PAni/α-Fe{sub 2}O{sub 3} nanocomposite films and their room temperature ammonia sensing activity

    Energy Technology Data Exchange (ETDEWEB)

    Bandgar, D.K. [Functional Materials Research Laboratory (FMRL), School of Physical Sciences, Solapur University, Solapur 413 255, M.S. (India); Navale, S.T. [College of Materials Science and Engineering, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, Nanshan District Key Lab for Biopolymers and Safety Evaluation, Shenzhen University, Shenzhen 518060 (China); Navale, Y.H.; Ingole, S.M. [Functional Materials Research Laboratory (FMRL), School of Physical Sciences, Solapur University, Solapur 413 255, M.S. (India); Stadler, F.J. [College of Materials Science and Engineering, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, Nanshan District Key Lab for Biopolymers and Safety Evaluation, Shenzhen University, Shenzhen 518060 (China); Ramgir, N.; Aswal, D.K.; Gupta, S.K. [Technical Physics Division, Babha Atomic Research Centre, Mumbai, M.S. (India); Mane, R.S. [School of Physical Sciences, SRTM University, Nanded 431606 (India); Patil, V.B., E-mail: drvbpatil@gmail.com [Functional Materials Research Laboratory (FMRL), School of Physical Sciences, Solapur University, Solapur 413 255, M.S. (India)

    2017-03-01

    Composite nanostructures play a crucial role in gas sensing applications owing to their tunable properties and sizes. The main goal of this article is to prepare camphor sulfonic acid (10–50 wt%)-doped PAni/α-Fe{sub 2}O{sub 3} (PFC) composite nanostructured films on flexible polyethylene terephthalate (PET) substrate through in-situ polymerization process and study their gas sensing activity towards various gases. Structural and morphological measurements along with gas sensing properties in terms of selectivity, response, stability, and response-recovery times are investigated and reported. The gas selectivity tests of flexible PFC nanostructured composite films are performed towards different gases such as NO{sub 2}, NH{sub 3}, LPG, CH{sub 3}OH, and C{sub 2}H{sub 5}OH etc., wherein all the flexible PFC (10–50%) films demonstrate a superior selectivity towards NH{sub 3} gas even in the presence of other test gases. Among the different compositions, 30% PFC flexible film exhibits highest response of 72% to 100 ppm NH{sub 3} with good response time of 65 s. The systematic study between PFC flexible nanocomposite films and NH{sub 3} gas is conducted and reported. In addition, the interfacial charge transfer kinetics across NH{sub 3} and PFC film interface was investigated by means of impendence spectroscopy study. - Highlights: • Novel route of preparation of camphor sulfonic acid doped PAni-Fe{sub 2}O{sub 3} (PFC) flexible films. • XRD, FTIR, and RAMAN analysis confirms the formation of PFC composites. • PFC films are highly selective towards NH{sub 3} gas at room temperature. • PFC films able to detect as low as 2.5 ppm concentration of NH{sub 3} gas. • 30% PFC flexible film exhibits highest response of 72%–100 ppm NH{sub 3} gas with good response time of 65 s.

  19. Optical characteristics of BaGa2S4:Ho3+ and BaGa2Se4:Ho3+ single crystals

    International Nuclear Information System (INIS)

    Choe, Sung-Hyu; Jin, Moon-Seog; Kim, Wha-Tek

    2005-01-01

    BaGa 2 S 4 , BaGa 2 S 4 :Ho 3+ , BaGa 2 Se 4 , and BaGa 2 Se 4 :Ho 3+ single crystals were grown by using the chemical transport reaction method. The optical energy gaps of the single crystals were investigated in the temperature region from 11 K to 300 K. The temperature dependence of the optical energy gap was well fitted by the Varshni equation. Two broad emission bands were observed in the photoluminescence spectra of the single crystals. These bands were attributed to donor-acceptor pair recombinations. Sharp emission peaks were observed in the BaGa 2 S 4 :Ho 3+ and the BaGa 2 Se 4 :Ho 3+ single crystals and were assigned to radiation recombination between split Stark levels of Ho 3+ .

  20. Hydrogen-bonding interactions in thiosemicarbazones of carboxylic acids: Structure of 2-ketobutyric acid thiosemicarbazone hemihydrate

    International Nuclear Information System (INIS)

    Sonawane, P.; Chikate, R.; Kumbhar, A.; Padhye, S.; Doedens, R.J.

    1991-01-01

    2-Thiosemicarbazonobutanoic acid hemihydrate, C 5 H 9 N 3 O 2 S.0.5H 2 O, M r =184.22, triclinic, Panti 1, a=8.163(2), b=8.868(2), c=12.438(2) A, α=72.99(2), β=79.47(2), γ=84.06(2)deg, V=845.3(3) A 3 , Z=4, D x =1.447 Mg m -3 , λ(Mo Kα)=0.71073 A, μ=0.332 mm -1 , F(000)=392, T=296 K, R=0.038 for 3830 independent reflections with I>3σ(I). Three hydrogen bonds link the two crystallographically independent molecules in a pairwise fashion. The two molecules both have E configurations about each C-N and N-N bond, but differ by nearly 180deg in the orientation of the -COOH group. (orig.)

  1. Dissociative multiple photoionization of SiBr4 and GeBr4 in the VUV and X-ray regions: a comparative study of inner-shell processes involving Si(2p, 2s), Ge(3d, 3p, 3s), and Br(3d, 3p, 3s)

    International Nuclear Information System (INIS)

    Boo, Bong Hyun; Saito, Norio

    2003-01-01

    Dissociative multiple photoionization of MBr 4 (M=Si, Ge) in the Si(2p, 2s), Ge(3d, 3s, 3p), and Br(3d, 3p, 3s) inner-shell regions has been studied by using time-of-flight (TOF) mass spectrometry coupled to synchrotron radiation in the ranges of 50∼944 eV for SiBr 4 and 50∼467 eV for GeBr 4 . Total photoion and photoion-photoion coincidence (PIPICO) yields have been measured as functions of the photon energy. Here, giant shape resonances have been observed beyond the thresholds of the 3d shells owing to the Br(3d 10 )→Br(3d 9 -f) excitation, showing the similar patterns for both of the systems. The ranges and the intensities of the shape resonances are found to be tremendously broad and enhanced, respectively, by the tetrahedral arrangement of the bromine ligands. In addition to the giant resonances, we have observed discrete features corresponding to the Br(3d), Si(2p), and Si(2s) in SiBr 4 and to the Br(3d), Ge(3p), and Ge(3s) in GeBr 4 . The dissociation processes of multiply charged parent ions have also been evaluated from the variations of photoelectron-photoion coincidence (PEPICO) and PIPICO yields with the photon energy. Over the entire energies examined, most efficient PIPICO channels involve Br + -Br + , Br + -MBr + , and M + -Br + (M=Si, Ge), the formation of which indicates that the total destruction of the molecules is a dominant process in the dissociative photoionization of the molecules

  2. Topological surface Fermi arcs in the magnetic Weyl semimetal Co3Sn2S2

    Science.gov (United States)

    Xu, Qiunan; Liu, Enke; Shi, Wujun; Muechler, Lukas; Gayles, Jacob; Felser, Claudia; Sun, Yan

    2018-06-01

    Very recently, the half-metallic compound Co3Sn2S2 was proposed to be a magnetic Weyl semimetal (WSM) with Weyl points only 60 meV above the Fermi level EF. Owing to the low charge carrier density and large Berry curvature induced, Co3Sn2S2 possesses both a large anomalous Hall conductivity and a large anomalous Hall angle, which provide strong evidence for the existence of Weyl points in Co3Sn2S2 . In this work, we theoretically study the surface topological feature of Co3Sn2S2 and its counterpart Co3Sn2Se2 . By cleaving the sample at the weak Sn-S/Se bonds, one can achieve two different surfaces terminated with Sn and S/Se atoms, respectively. The resulting Fermi-arc-related states can range from the energy of the Weyl points to EF-0.1 eV in the Sn-terminated surface. Therefore, it should be possible to observe the Fermi arcs in angle-resolved photoemission spectroscopy (ARPES) measurements. Furthermore, in order to simulate quasiparticle interference in scanning tunneling microscopy (STM) measurements, we also calculate the joint density of states for both terminals. This work should be helpful for a comprehensive understanding of the topological properties of these two magnetic WSMs and further ARPES and STM measurements.

  3. 2, 3-dimercaptosuccinic acid-modified iron oxide clusters for magnetic resonance imaging.

    Science.gov (United States)

    Xiong, Fei; Yan, Caiyun; Tian, Jilai; Geng, Kunkun; Zhu, Ziyi; Song, Lina; Zhang, Yu; Mulvale, Matthew; Gu, Ning

    2014-12-01

    Over the last decade, various magnetic nanomaterials have been developed as magnetic resonance imaging (MRI) contrast agents; the greatest challenges encountered for clinical application have been insufficient stability. In this paper, a lyophilization method for 2, 3-dimercaptosuccinic acid-modified iron oxide (γ-Fe2 O3 @DMSA) nanoparticles was developed to simultaneously overcome two disadvantages; these include insufficient stability and low-magnetic response. After lyophilization, the clusters of γ-Fe2 O3 @DMSA with the size of 156.7 ± 15.3 nm were formed, and the stability of the lyophilized powder (γ-Fe2 O3 @DMSA-LP) increased up to over 3 years. It was also found that rehydrated γ-Fe2 O3 @DMSA-LP could be ingested by RAW264.7 cells in very large quantities. Results of pharmacokinetics and biodistribution studies in vivo indicated that γ-Fe2 O3 @DMSA-LP is a promising liver-targeted material. Furthermore, it also exhibited higher MRI efficiency and longer imaging time in the liver than the well-known product Feridex(®) . Moreover, results of vascular irritation and long-term toxicity experiments demonstrated γ-Fe2 O3 @DMSA-LP could be a nontoxic, biocompatible contrast agent in vivo. Therefore, the proposed γ-Fe2 O3 @DMSA-LP can be used as a potential MRI contrast agent in clinic for hepatic diseases. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  4. Enhanced photoelectrocatalytic degradation of 2,4-dichlorophenoxyacetic acid by CuInS2 nanoparticles deposition onto TiO2 nanotube arrays

    International Nuclear Information System (INIS)

    Liu Ronghua; Liu Yutang; Liu Chengbin; Luo Shenglian; Teng Yarong; Yang Lixia; Yang Renbin; Cai Qingyun

    2011-01-01

    Research highlights: → The photocatalytic application of CuInS 2 with a direct band gap of about 1.5 eV and a high absorption coefficient remains unknown. → We describe an impulse electrodeposition approach to deposit CuInS 2 nanoparticles in uniform size of about 20 nm onto the top surface of the highly oriented TiO 2 NT arrays while minimizing the clogging of the tube entrances. → The novel photocatalyst exhibits a highly visible-light photocatalytic degradation activity for the target organic pollutant. → Moreover, the stability of the modified TiO 2 NT is good. → Therefore, CuInS 2 nanoparticles modified TiO 2 NT photocatalysts have potential utility in practical purification of organic wastewater. - Abstract: Surface modification of TiO 2 nanotube (NT) arrays with CuInS 2 nanoparticles (NPs) for photocatalytic degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) was reported. A pulse electrodeposition technique was used to prepare the CuInS 2 NPs, and the resulted CuInS 2 NPs, with a uniform size of about 20 nm, were found to deposit on the top surface of the highly oriented TiO 2 NT while without clogging the tube entrances. Compared with the unmodified TiO 2 NT, the CuInS 2 NPs modified TiO 2 NT (CuInS 2 -TiO 2 NT) showed significantly enhanced photocatalytic activity towards 2,4-D under visible light. After 160 min irradiation, the removal rate of 2,4-D is 100% by using CuInS 2 -TiO 2 NT, much higher than 65.2% by using the unmodified TiO 2 NT in photoelectrocatalytic process. The increased photodegradation efficiency mainly results from the improved photocurrent density as results of enhanced visible-light absorption and decreased hole-electron recombination due to the presence of narrow-band-gap p-type semiconductor CuInS 2 .

  5. Optical and structural study of In{sub 2}S{sub 3} thin films growth by co-evaporation and chemical bath deposition (CBD) on Cu{sub 3}BiS{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Mesa, F., E-mail: fgmesar@unal.edu.co [Unidad de Estudios Universitarios, Colegio Mayor de Nuestra Señora del Rosario, Cra. 24 N° 63C-69, Bogotá (Colombia); Chamorro, W. [Université de Lorraine, Institut Jean Lamour, Nancy (France); Hurtado, M. [Departamento de Quimica, Universidad Nacional de Colombia, Cra. 30 N° 45-03, Bogotá (Colombia); Departamento de Física, Universidad de los Andes, Calle 21 No. 1-20, Bogotá (Colombia)

    2015-09-30

    Highlights: • In{sub 2}S{sub 3} thin films usually grow like an ultrathin. • Samples grown by CBD have a higher degree of coverage of the substrate unlike co-evaporation method. • Solar cells of Al/TCO/In{sub 2}S{sub 3}/Cu{sub 3}BiS{sub 3}/Mo structure. • In{sub 2}S{sub 3} thin films were deposited on Cu{sub 3}BiS{sub 3} (CBS), with of In{sub 2}S{sub 3} β-phase with tetragonal structure. - Abstract: We present the growth of In{sub 2}S{sub 3} onto Cu{sub 3}BiS{sub 3} layers and soda-lime glass (SLG) substrates by using chemical bath deposition (CBD) and physical co-evaporation. The results reveal that the microstructure and the optical properties of the In{sub 2}S{sub 3} films are highly dependent on the growth method. X-ray diffractrograms show that In{sub 2}S{sub 3} films have a higher crystallinity when growing by co-evaporation than by CBD. In{sub 2}S{sub 3} thin films grown by CBD with a thickness below 170 nm have an amorphous structure however when increasing the thickness the films exhibit two diffraction peaks associated to the (1 0 3) and (1 0 7) planes of the β-In{sub 2}S{sub 3} tetragonal structure. It was also found that the In{sub 2}S{sub 3} films present an energy bandgap (E{sub g}) of about 2.75 eV, regardless of the thickness of the samples.

  6. sPLA2-IIA

    Indian Academy of Sciences (India)

    67

    Recent research showed that maslinic acid interacts with sPLA2-IIA ... Further analysis revealed that sPLA2-IIA only induced modest LDL ..... MDA/mg protein) compared to native LDL (2.043 nmol MDA/mg protein) while .... to modify extracellular non-cellular lipid components such as lipoproteins, ... The main pathway for.

  7. MINERALIZATION OF THE HERBICIDE 2,3,6-TRICHLOROBENZOIC ACID BY A COCULTURE OF ANAEROBIC AND AEROBIC-BACTERIA

    NARCIS (Netherlands)

    GERRITSE, J; GOTTSCHAL, JC

    1992-01-01

    Bacteria from an anaerobic enrichment reductively removed chlorine from the ortho- position of 2,3,6-trichlorobenzoic acid (2,3,6-TBA) producing 2,5-dichlorobenzoate (2,5-DBA). The strictly aerobic bacterium Pseudomonas aeruginosa JB2 subsequently used 2,5-DBA as a growth substrate in the presence

  8. Mineralization of herbicide 3,6-dichloro-2-methoxybenzoic acid in aqueous medium by anodic oxidation, electro-Fenton and photoelectro-Fenton

    International Nuclear Information System (INIS)

    Brillas, Enric; Banos, Miguel Angel; Garrido, Jose Antonio

    2003-01-01

    The mineralization of acidic aqueous solutions with 230 and 115 ppm of herbicide 3,6-dichloro-2-methoxybenzoic acid (dicamba) in 0.05 M Na 2 SO 4 of pH 3.0 has been studied by electro-Fenton and photoelectro-Fenton using a Pt anode and an O 2 -diffusion cathode, where oxidizing hydroxyl radicals are produced from Fenton's reaction between added Fe 2+ and H 2 O 2 generated by the cathode. While electro-Fenton only yields 60-70% mineralization, photoelectro-Fenton allows a fast and complete depollution of herbicide solutions, even at low currents, by the action of UV irradiation. In both treatments, the initial chlorine is rapidly released to the medium as chloride ion. Comparative electrolyses by anodic oxidation in the absence and presence of electrogenerated H 2 O 2 give very poor degradation. The dicamba decay follows a pseudo-first-order reaction, as determined by reverse-phase chromatography. Formic, maleic and oxalic acids have been detected in the electrolyzed solutions by ion-exclusion chromatography. In electro-Fenton, all formic acid is transformed into CO 2 , and maleic acid is completely converted into oxalic acid, remaining stable Fe 3+ -oxalato complexes in the solution. The fast mineralization of such complexes by UV light explains the highest oxidative ability of photoelectro-Fenton

  9. SILAR deposited Bi2S3 thin film towards electrochemical supercapacitor

    Science.gov (United States)

    Raut, Shrikant S.; Dhobale, Jyotsna A.; Sankapal, Babasaheb R.

    2017-03-01

    Bi2S3 thin film electrode has been synthesized by simple and low cost successive ionic layer adsorption and reaction (SILAR) method on stainless steel (SS) substrate at room temperature. The formation of interconnected nanoparticles with nanoporous surface morphology has been achieved and which is favourable to the supercapacitor applications. Electrochemical supercapacitive performance of Bi2S3 thin film electrode has been performed through cyclic voltammetry, charge-discharge and stability studies in aqueous Na2SO4 electrolyte. The Bi2S3 thin film electrode exhibits the specific capacitance of 289 Fg-1 at 5 mVs-1 scan rate in 1 M Na2SO4 electrolyte.

  10. Omega-3 Fatty Acids in Early Prevention of Inflammatory Neurodegenerative Disease: A Focus on Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    J. Thomas

    2015-01-01

    Full Text Available Alzheimer’s disease (AD is the leading cause of dementia and the most common neurodegenerative disease in the elderly. Furthermore, AD has provided the most positive indication to support the fact that inflammation contributes to neurodegenerative disease. The exact etiology of AD is unknown, but environmental and genetic factors are thought to contribute, such as advancing age, family history, presence of chronic diseases such as cardiovascular disease (CVD and diabetes, and poor diet and lifestyle. It is hypothesised that early prevention or management of inflammation could delay the onset or reduce the symptoms of AD. Normal physiological changes to the brain with ageing include depletion of long chain omega-3 fatty acids and brains of AD patients have lower docosahexaenoic acid (DHA levels. DHA supplementation can reduce markers of inflammation. This review specifically focusses on the evidence in humans from epidemiological, dietary intervention, and supplementation studies, which supports the role of long chain omega-3 fatty acids in the prevention or delay of cognitive decline in AD in its early stages. Longer term trials with long chain omega-3 supplementation in early stage AD are warranted. We also highlight the importance of overall quality and composition of the diet to protect against AD and dementia.

  11. Treatment of landfill leachate biochemical effluent using the nano-Fe3O4/Na2S2O8 system: Oxidation performance, wastewater spectral analysis, and activator characterization.

    Science.gov (United States)

    Liu, Zhanmeng; Li, Xian; Rao, Zhiwei; Hu, Fengping

    2018-02-15

    Nano-Fe 3 O 4 was used as heterogeneous catalyst to activate Na 2 S 2 O 8 for the generation of the sulfate radicals (SO 4 - ) to oxidize the residual pollutants in landfill leachate biochemical effluent. The oxidation performance, wastewater spectral analysis and activator characterization were discussed. Oxidation experimental result shows that nano-Fe 3 O 4 has obvious catalytic effect on Na 2 S 2 O 8 and can significantly enhance the oxidation efficiencies of Na 2 S 2 O 8 on landfill leachate biochemical effluent, with COD and color removals above 63% and 95%, respectively. Based on the analyses of three-dimensional excitation emission matrix fluorescence spectrum (3DEEM), ultraviolet-visible spectra (UV-vis), and Fourier Transform infrared spectroscopy (FTIR) of wastewater samples before and after treatment, it can be concluded that the pollution level of dissolved organic matter (DOM) declined and that the humic acid (HA) fractions were efficiently degraded into small molecules of fulvic acid (FA) fractions with less weight and stable structure. Compared to the raw wastewater sample, the aromaticity and substituent groups of the DOM were lessened in the treated wastewater sample. Moreover, the main structure of the organics and functional groups were changed by the Fe 3 O 4 /Na 2 S 2 O 8 system, with substantial decrease of conjugated double bonds. The micro morphology of nano-Fe 3 O 4 was characterized before and after reaction by the methods of scanning electron microscope spectra (SEM), X-ray diffraction pattern (XRD), and X-ray photoelectron spectroscopy (XPS). The XRD pattern analysis showed that nano-Fe 3 O 4 was oxidized into r-Fe 2 O 3 and that the particle size of it also became smaller after reaction. XPS was employed to analyze the content and iron valence on the nano-Fe 3 O 4 surface, and it can be found that the ratio of Fe 3+ /Fe 2+ decreased from 1.8 before reaction to 0.8 after reaction. From the SEM analysis after the treatment, it was

  12. Preparation of 2H- and 3H-labeled phaseic acid and dihydrophaseic acid as standards for determination of abscisic acid metabolites in tomato fruit

    International Nuclear Information System (INIS)

    Kubik, M.; Buta, J.G.

    1990-01-01

    There have been reports that the level of abscisic acid (ABA) increases during the cold storage of tomatoes. However, the important ABA metabolites, phaseic acid (PA) and dihydrophaseic acid (DPA) were never quantitatively determined in such a system. In order to obtain the labeled standards for quantitative determination of those compounds by GC-MS-SIM, we fed bean plants with 6,6,6-[ 2 H 3 ]-ABA (mean isotopic enrichment 60%) with addition of about 10 5 Bq per mg of [ 3 H]-ABA. After 100 hours the plants were harvested and extracted with acetone. The extract were purified by solvent partitioning and, Prep-Sep amino column and on an HPLC C 18 reverse phase column. Two major radioactive metabolites of ABA were obtained and identified by GC-MS as PA and DPA. Some results on the quantitation of ABA, PA and DPA in tomato fruit after cold storage will be presented

  13. Electrical and optical characterization of green synthesized Gd{sub 2}S{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Somnath, E-mail: somnathpaul459@gmail.com; Sarkar, A. [Dept of Physics, Bijoy Krishna Girls’ College, 5/3, M. G. Road, Howrah-711101 (India)

    2016-05-06

    Gadolinium sulphide (Gd{sub 2}S{sub 3}) is a magnetic semiconductor with large band gap. Gd{sub 2}S{sub 3} was synthesized following chemical and green techniques. Later process provides good stability of the nano clusters (NC) due to in-situ capping of Gd{sub 2}S{sub 3} NC. It has been found that the optical band gap in Gd{sub 2}S{sub 3} developed by green synthesis is lowered considerably over that in chemically synthesized Gd{sub 2}S{sub 3}. The green agencies used in this work are Jatropha Latex and dilute Garlic extract; both are enriched in sulphur and other organic polymer molecules. Simple observation shows that Gd{sub 2}S{sub 3} NC retains residual magnetization. In this work optical and electrical characterization of the developed Gd{sub 2}S{sub 3} specimens are carried out. The overall results obtained are good.

  14. Structural similarity between β(3)-peptides synthesized from β(3)-homo-amino acids and aspartic acid monomers.

    Science.gov (United States)

    Ahmed, Sahar; Sprules, Tara; Kaur, Kamaljit

    2014-07-01

    Formation of stable secondary structures by oligomers that mimic natural peptides is a key asset for enhanced biological response. Here we show that oligomeric β(3)-hexapeptides synthesized from L-aspartic acid monomers (β(3)-peptides 1, 5a, and 6) or homologated β(3)-amino acids (β(3)-peptide 2), fold into similar stable 14-helical secondary structures in solution, except that the former form right-handed 14-helix and the later form left-handed 14-helix. β(3)-Peptides from L-Asp monomers contain an additional amide bond in the side chains that provides opportunities for more hydrogen bonding. However, based on the NMR solution structures, we found that β(3)-peptide from L-Asp monomers (1) and from homologated amino acids (2) form similar structures with no additional side-chain interactions. These results suggest that the β(3)-peptides derived from L-Asp are promising peptide-mimetics that can be readily synthesized using L-Asp monomers as well as the right-handed 14-helical conformation of these β(3)-peptides (such as 1 and 6) may prove beneficial in the design of mimics for right-handed α-helix of α-peptides. © 2014 Wiley Periodicals, Inc.

  15. Synergy by secretory phospholipase A2 and glutamate on inducing cell death and sustained arachidonic acid metabolic changes in primary cortical neuronal cultures

    DEFF Research Database (Denmark)

    Kolko, M; DeCoster, M A; de Turco, E B

    1996-01-01

    glutamate and sPLA2 from bee venom. sPLA2, at concentrations eliciting low neurotoxicity (acid into triacylglycerols. Free [3H]arachidonic acid accumulated at higher enzyme concentrations......, from Taipan snake venom. The NMDA receptor antagonist MK-801 blocked glutamate effects and partially inhibited sPLA2 OS2 but not sPLA2 from bee venom-induced arachidonic acid release. Thus, the synergy with glutamate and very low concentrations of exogenously added sPLA2 suggests a potential role......Secretory and cytosolic phospholipases A2 (sPLA2 and cPLA2) may contribute to the release of arachidonic acid and other bioactive lipids, which are modulators of synaptic function. In primary cortical neuron cultures, neurotoxic cell death and [3H]arachidonate metabolism was studied after adding...

  16. Simultaneous determination of mercapturic acids derived from ethylene oxide (HEMA), propylene oxide (2-HPMA), acrolein (3-HPMA), acrylamide (AAMA) and N,N-dimethylformamide (AMCC) in human urine using liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Schettgen, Thomas; Musiol, Anita; Kraus, Thomas

    2008-09-01

    Mercapturic acids are highly important and specific biomarkers of exposure to carcinogenic substances in occupational and environmental medicine. We have developed and validated a reliable, specific and very sensitive method for the simultaneous determination of five mercapturic acids derived from several high-production chemicals used in industry, namely ethylene oxide, propylene oxide, acrylamide, acrolein and N,N-dimethylformamide. Analytes are enriched and cleaned up from urinary matrix by offline solid-phase extraction. The mercapturic acids are subsequently separated by means of high-performance liquid chromatography on a Luna C8 (2) column and specifically quantified by tandem mass spectrometric detection using isotopically labelled analytes as internal standards. The limits of detection (LODs) for N-acetyl-S-2-carbamoylethylcysteine (AAMA) and N-acetyl-S-2-hydroxyethylcysteine (HEMA) were 2.5 microg/L and 0.5 microg/L urine, while for N-acetyl-S-3-hydroxypropylcysteine (3-HPMA), N-acetyl-S-2-hydroxypropylcysteine (2-HPMA) and N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) it was 5 microg/L. These LODs were sufficient to detect the background exposure of the general population. We applied the method on spot urine samples of 28 subjects of the general population with no known occupational exposure to these substances. Median levels for AAMA, HEMA, 3-HPMA, 2-HPMA and AMCC in non-smokers (n = 14) were 52.6, 2.0, 155, 7.1 and 113.6 microg/L, respectively. In smokers (n = 14), median levels for AAMA, HEMA, 3-HPMA, 2-HPMA and AMCC were 243, 5.3, 1681, 41.7 and 822 microg/L, respectively. Due to the simultaneous quantification of these mercapturic acids, our method is well suited for the screening of workers with multiple chemical exposures as well as the determination of the background excretion of the general population.

  17. Discovery of a New Class of Sortase A Transpeptidase Inhibitors to Tackle Gram-Positive Pathogens: 2-(2-Phenylhydrazinylidenealkanoic Acids and Related Derivatives

    Directory of Open Access Journals (Sweden)

    Benedetta Maggio

    2016-02-01

    Full Text Available A FRET-based random screening assay was used to generate hit compounds as sortase A inhibitors that allowed us to identify ethyl 3-oxo-2-(2-phenylhydrazinylidenebutanoate as an example of a new class of sortase A inhibitors. Other analogues were generated by changing the ethoxycarbonyl function for a carboxy, cyano or amide group, or introducing substituents in the phenyl ring of the ester and acid derivatives. The most active derivative found was 3-oxo-2-(2-(3,4dichlorophenylhydrazinylidenebutanoic acid (2b, showing an IC50 value of 50 µM. For a preliminary assessment of their antivirulence properties the new derivatives were tested for their antibiofilm activity. The most active compound resulted 2a, which showed inhibition of about 60% against S. aureus ATCC 29213, S. aureus ATCC 25923, S. aureus ATCC 6538 and S. epidermidis RP62A at a screening concentration of 100 µM.

  18. A 2D nickel-based energetic MOFs incorporating 3,5-diamino-1,2,4-triazole and malonic acid: Synthesis, crystal structure and thermochemical study

    International Nuclear Information System (INIS)

    Yang, Qi; Song, Xiaxia; Ge, Jing; Zhao, Guowei; Zhang, Wendou; Xie, Gang; Chen, Sanping; Gao, Shengli

    2016-01-01

    Highlights: • An energetic MOFs with dinuclear nickel unit has been synthesized and characterized. • The Arrhenius equation, derived from kinetics analysis, is ln k = 55.89 − 332.01 × 10 3 /RT. • The standard molar enthalpy of formation of the compound is determined by a thermochemical cycle. • The molar heat capacity at T = 298.15 K is determined to be 1.42 ± 0.11 J · K −1 · g −1 . - Abstract: A new energetic MOFs, {[Ni 2 (C 2 H 5 N 5 ) 2 (C 3 H 2 O 4 ) 2 (H 2 O)]·3H 2 O} n (Hdatrz (C 2 H 5 N 5 ) = 3,5-diamino-1,2,4-triazole, H 2 mal (C 3 H 4 O 4 ) = malonic acid), has been synthesized and characterized by element analysis, chemical analysis, IR spectroscopy, single-crystal X-ray diffraction and thermal analysis. X-ray diffraction analysis confirmed that the compound featured a 2D layer structure with dinuclear Ni(II) unit. Thermal analysis demonstrated that the compound after dehydration have good thermostability with decomposition temperature up to 633 K. The non-isothermal kinetics for the compound was studied by Kissinger’s and Ozawa’s methods. The Arrhenius equation of initial thermal decomposition process of compound can be expressed as ln k = 55.89 − 332.01 × 10 3 /RT. Furthermore, a reasonable thermochemical cycle was designed based on the preparation reaction of the compound, and standard molar enthalpy of dissolution of reactants and products were measured by RD496-2000 calorimeter. Finally, the standard molar enthalpy of formation of the compound was determined to be −(2766.3 ± 2.3) kJ · mol −1 in accordance with Hess’s law. In addition, the specific heat capacity of the compound at T = 298.15 K was determined to be 1.42 ± 0.11 J · K −1 · g −1 by RD496-2000 calorimeter.

  19. Paramagnetic relaxation enhancement of membrane proteins by incorporation of the metal-chelating unnatural amino acid 2-amino-3-(8-hydroxyquinolin-3-yl)propanoic acid (HQA)

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang Ho; Wang, Vivian S.; Radoicic, Jasmina; Angelis, Anna A. De; Berkamp, Sabrina; Opella, Stanley J., E-mail: sopella@ucsd.edu [University of California, San Diego, Department of Chemistry and Biochemistry (United States)

    2015-04-15

    The use of paramagnetic constraints in protein NMR is an active area of research because of the benefits of long-range distance measurements (>10 Å). One of the main issues in successful execution is the incorporation of a paramagnetic metal ion into diamagnetic proteins. The most common metal ion tags are relatively long aliphatic chains attached to the side chain of a selected cysteine residue with a chelating group at the end where it can undergo substantial internal motions, decreasing the accuracy of the method. An attractive alternative approach is to incorporate an unnatural amino acid that binds metal ions at a specific site on the protein using the methods of molecular biology. Here we describe the successful incorporation of the unnatural amino acid 2-amino-3-(8-hydroxyquinolin-3-yl)propanoic acid (HQA) into two different membrane proteins by heterologous expression in E. coli. Fluorescence and NMR experiments demonstrate complete replacement of the natural amino acid with HQA and stable metal chelation by the mutated proteins. Evidence of site-specific intra- and inter-molecular PREs by NMR in micelle solutions sets the stage for the use of HQA incorporation in solid-state NMR structure determinations of membrane proteins in phospholipid bilayers.

  20. CuInS{sub 2} thin films obtained through the annealing of chemically deposited In{sub 2}S{sub 3}-CuS thin films

    Energy Technology Data Exchange (ETDEWEB)

    Pena, Y., E-mail: yolapm@gmail.com [Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon, Pedro de Alba S/N, Ciudad Universitaria, 66451, San Nicolas de los Garza, Nuevo Leon (Mexico); Lugo, S. [Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon, Pedro de Alba S/N, Ciudad Universitaria, 66451, San Nicolas de los Garza, Nuevo Leon (Mexico); Calixto-Rodriguez, M. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, Privada Xochicalco S/N, Col Centro, 62580, Temixco, Morelos (Mexico); Vazquez, A.; Gomez, I.; Elizondo, P. [Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon, Pedro de Alba S/N, Ciudad Universitaria, 66451, San Nicolas de los Garza, Nuevo Leon (Mexico)

    2011-01-01

    In this work, we report the formation of CuInS{sub 2} thin films on glass substrates by heating chemically deposited multilayers of copper sulfide (CuS) and indium sulfide (In{sub 2}S{sub 3}) at 300 and 350 deg. C in nitrogen atmosphere at 10 Torr. CIS thin films were prepared by varying the CuS layer thickness in the multilayers with indium sulfide. The XRD analysis showed that the crystallographic structure of the CuInS{sub 2} (JCPDS 27-0159) is present on the deposited films. From the optical analysis it was estimated the band gap value for the CIS film (1.49 eV). The electrical conductivity varies from 3 x 10{sup -8} to 3 {Omega}{sup -1} cm{sup -1} depending on the thickness of the CuS film. CIS films showed p-type conductivity.

  1. Long-chain omega-3 fatty acids, fish intake, and the risk of type 2 diabetes mellitus123

    OpenAIRE

    Kaushik, Manas; Mozaffarian, Dariush; Spiegelman, Donna; Manson, JoAnn E; Willett, Walter C; Hu, Frank B

    2009-01-01

    Background: Diet is a key component of a healthy lifestyle in the prevention of type 2 diabetes mellitus (T2DM). The role of long-chain omega-3 (n–3) fatty acids (LCFAs) in the development of T2DM remains unresolved.

  2. Omega-3 fatty acids promote fatty acid utilization and production of pro-resolving lipid mediators in alternatively activated adipose tissue macrophages

    Czech Academy of Sciences Publication Activity Database

    Rombaldová, Martina; Janovská, Petra; Kopecký, Jan; Kuda, Ondřej

    2017-01-01

    Roč. 490, č. 3 (2017), s. 1080-1085 ISSN 0006-291X R&D Projects: GA ČR(CZ) GA16-05151S; GA MŠk(CZ) LTAUSA17173 Institutional support: RVO:67985823 Keywords : adipose tissue * macrophages * omega-3 PUFA * fatty acid re-esterification * lipolysis * lipid mediators Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition OBOR OECD: Endocrinology and metabolism (including diabetes, hormones) Impact factor: 2.466, year: 2016

  3. (1R,2R,3R,4R,5S-2,3-Bis[(2S′-2-acetoxy-2-phenylacetoxy]-4-azido-1-[(2,4-dinitrophenylhydrazonomethyl]bicyclo[3.1.0]hexane

    Directory of Open Access Journals (Sweden)

    Robert McDonald

    2008-02-01

    Full Text Available In the title compound, C38H29N7O12, the five-membered ring adopts an envelope conformation in which the `flap' is cis to the cyclopropane group. This conformation is similar to those of other bicyclo[3.1.0]hexane analogues for which crystal structures have been reported. The absolute configuration of the stereogenic centers on the cyclopentane ring, as determined by comparison with the known configurations of the stereogenic centers in the (2S-2-acetoxy-2-phenylacetoxy groups, is 1(R, 2(R, 3(R, 4(R and 5(S. An intramolecular N—H...O hydrogen bond is present.

  4. Design of a Free-Ruthenium In2S3 Crystalline Photosensitized Solar Cell

    Directory of Open Access Journals (Sweden)

    Byeong Sub Kwak

    2014-01-01

    Full Text Available A new type of sulfide-based, solid-state dye material that is sensitive to visible radiation was assessed as a potential replacement for commercial ruthenium complex dyes in a dye-sensitized solar cell (DSSC assembly. The In2S3 crystals on the surface of the TiO2 bottom blocking layer were grown as a solid-state dye material. Scanning electron microscopy of In2S3 revealed a microsized, 3D-connected sheet-like shape, which was confirmed by X-ray diffraction to be a beta-structure. The efficiency of the dye-sensitized solar cells assembled with a layer grown with In2S3 increased with increasing In2S3 mole concentrations to 0.05 M (1.02% but decreased at concentrations greater than 0.6~0.8%. This suggests that crystalline In2S3 acts as a dye sensitized to visible radiation, but the short-circuit current density is too low compared to the commercially available ruthenium dye. This suggests that In2S3 crystals did not grow densely but were bulk-grown with large pores, resulting in a smaller amount of In2S3 per unit area. Two IPCE curves were observed, which were assigned to TiO2 and In2S3, meaning that the TiO2 surfaces were covered completely with In2S3 crystals. The exposure of TiO2 eventually leads to a reaction with the electrolytes, resulting in lower quantum efficiency.

  5. N-methyl-D-aspartic acid receptor agonists

    DEFF Research Database (Denmark)

    Madsen, U; Frydenvang, Karla Andrea; Ebert, B

    1996-01-01

    (R,S)-2-Amino-2-(3-hydroxy-5-methyl-4-isoxazolyl)acetic acid [(R,S)-AMAA, 4] is a potent and selective agonist at the N-methyl-D-aspartic acid (NMDA) subtype of excitatory amino acid receptors. Using the Ugi "four-component condensation" method, the two diastereomers (2R)- and (2S)-2-[3-(benzyloxy......) showed peak affinity for [3H]AMPA receptor sites (IC50 = 72 +/- 13 microM) and was shown to be a more potent inhibitor of [3H]CPP binding (IC50 = 3.7 +/- 1.5 microM) than (S)-AMAA (9) (IC50 = 61 +/- 6.4 microM). Neither enantiomer of AMAA affected [3H]kainic acid receptor binding significantly...

  6. Interaction between Al3+ and acrylic acid and polyacrylic acid in acidic aqueous solution: a model experiment for the behavior of Al3+ in acidified soil solution.

    Science.gov (United States)

    Etou, Mayumi; Masaki, Yuka; Tsuji, Yutaka; Saito, Tomoyuki; Bai, Shuqin; Nishida, Ikuko; Okaue, Yoshihiro; Yokoyama, Takushi

    2011-01-01

    From the viewpoint of the phytotoxicity and mobility of Al(3+) released from soil minerals due to soil acidification, the interaction between Al(3+) and acrylic acid (AA) and polyacrylic acid (PAA) as a model compound of fulvic acid was investigated. The interaction was examined at pH 3 so as to avoid the hydrolysis of Al(3+). The interaction between Al(3+) and AA was weak. However, the interaction between Al(3+) and PAA was strong and depended on the initial (COOH in PAA)/Al molar ratio (R(P)) of the solution. For the range of 1/R(P), the interaction between Al(3+) and PAA can be divided into three categories: (1) 1:1 Al-PAA-complex (an Al(3+) combines to a carboxyl group), (2) intermolecular Al-PAA-complex (an Al(3+) combines to more than 2 carboxyl groups of other Al-PAA-complexes) in addition to the 1:1 Al-PAA-complex and (3) precipitation of intermolecular complexes. In conclusion, R(P) is an important factor affecting the behavior of Al(3+) in acidic soil solution.

  7. Constitutively active Arabidopsis MAP Kinase 3 triggers defense responses involving salicylic acid and SUMM2 resistance protein

    KAUST Repository

    Genot, Baptiste; Lang, Julien; Berriri, Souha; Garmier, Marie; Gilard, Franç oise; Pateyron, Sté phanie; Haustraete, Katrien; Van Der Straeten, Dominique; Hirt, Heribert; Colcombet, Jean

    2017-01-01

    ), phytoalexins and the stress-related hormones ethylene and salicylic acid (SA). Remarkably CA-MPK3/sid2 and CA-MPK3/ein2-50 lines which are impaired in SA synthesis and ethylene signaling, respectively, retain most of the CA-MPK3-associated phenotypes

  8. Calculation of HNO2 concentration from redox potential in HNO3-H2O system as an aid to understanding the cathodic reaction of nitric acid corrosion

    International Nuclear Information System (INIS)

    Takeuchi, Masayuki; Whillock, G.O.H.

    2002-01-01

    Nitrous acid affects the corrosion of metals such as stainless steels in nitric acid. However nitrous acid is not particularly stable in nitric acid and the analytical methods available are quite involved. Accordingly, the calculation of nitrous acid concentration from redox potential was tested in the HNO 3 -H 2 O system as a convenient in situ analysis method. The calculation process is based on Nernst's equation and the required thermodynamic data were obtained from published values. The available thermodynamic data allow calculation of nitrous acid concentration from 273K to 373K for 0%-100% HNO 3 . The redox potential was 8 kmol·m -3 HNO 3 under NO bubbling and the nitrous acid concentration was determined by a Colourimetric method. The calculated data were compared with the measured data and a good agreement was found. It was found that the corrosion potential of stainless steel is influenced by nitrous acid concentration in nitric acid solution. The calculation process is useful for in-situ analysis of nitrous acid species in HNO 3 -H 2 O system and understanding the behavior of the cathodic reaction associated with nitric acid corrosion. (author)

  9. Anodic Aluminum Oxide Membrane-Assisted Fabrication of beta-In(2)S(3) Nanowires.

    Science.gov (United States)

    Shi, Jen-Bin; Chen, Chih-Jung; Lin, Ya-Ting; Hsu, Wen-Chia; Chen, Yu-Cheng; Wu, Po-Feng

    2009-06-06

    In this study, beta-In(2)S(3) nanowires were first synthesized by sulfurizing the pure Indium (In) nanowires in an AAO membrane. As FE-SEM results, beta-In(2)S(3) nanowires are highly ordered, arranged tightly corresponding to the high porosity of the AAO membrane used. The diameter of the beta-In(2)S(3) nanowires is about 60 nm with the length of about 6-8 mum. Moreover, the aspect ratio of beta-In(2)S(3) nanowires is up to 117. An EDS analysis revealed the beta-In(2)S(3) nanowires with an atomic ratio of nearly S/In = 1.5. X-ray diffraction and corresponding selected area electron diffraction patterns demonstrated that the beta-In(2)S(3) nanowire is tetragonal polycrystalline. The direct band gap energy (E(g)) is 2.40 eV from the optical measurement, and it is reasonable with literature.

  10. Synthesis, characterization, and thermochemistry of the solid state coordination compound Zn(Nic){sub 2} . H{sub 2}O(s) (Nic = nicotinic acid)

    Energy Technology Data Exchange (ETDEWEB)

    Di Youying [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, Shandong (China)], E-mail: yydi@lcu.edu.cn; Hong Yuanping; Kong Yuxia; Yang Weiwei [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, Shandong (China); Tan Zhicheng [Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China)

    2009-01-15

    A novel compound, viz. zinc nicotinate monohydrate, was synthesized by the method of room temperature solid phase synthesis. The techniques of FT-IR chemical and elemental analyses and X-ray powder diffraction were applied to characterise the structure and composition of the complex. In accordance with Hess' law, a thermochemical cycle was designed and the enthalpy change of the solid phase reaction of nicotinic acid with hydrated zinc acetate was determined to be {delta}{sub r}H{sub m}{sup 0}=(46.71{+-}0.21)kJ.mol{sup -1} by use of an isoperibol solution-reaction calorimeter. The standard molar enthalpy of formation of the title complex Zn(Nic){sub 2} . H{sub 2}O(s) was calculated as -(1062.3 {+-} 2.0) kJ . mol{sup -1} by use of the enthalpies of dissolution and other auxiliary thermodynamic data.

  11. Bi2Se3/CdS/TiO2 hybrid photoelectrode and its band-edge levels

    International Nuclear Information System (INIS)

    Zhang, Qi; Su, Jun; Zhang, Xianghui; Li, Jian; Zhang, Aiqing; Gao, Yihua

    2012-01-01

    Highlights: ► CVD synthesis of Bi 2 Se 3 nanoparticles. ► Bi 2 Se 3 and CdS co-sensitized TiO 2 nanorod arrays electrode was assembled by CVD. ► Direct physical contact heterojunctions were formed at the interfaces of electrode. ► Cascade structure of band-edge levels was formed in Bi 2 Se 3 /CdS/TiO 2 electrode. - Abstract: Bismuth selenide (Bi 2 Se 3 ) was chosen as the sensitizer to TiO 2 nanorod (NR) arrays photoelectrode to harvest infrared (IR) light for its narrow band gap. For utilizing more amount of IR solar energy, Bi 2 Se 3 nanoparticles (NPs) were grown up to a relative larger grain size. And, a cadmium sulfide (CdS) NPs intermediate layer was introduced to help, to coordinate, the structure of band-edge levels in Bi 2 Se 3 /CdS/TiO 2 electrode. Here, a chemical vapor deposition (CVD) strategy was introduced to assemble this kind of composite photoelectrode. And a cascade structure of band-edge levels constructed in it when achieving electrostatic equilibrium in Na 2 S/Na 2 SO 3 aqueous solution electrolyte revealed by electrochemical analysis method, which will facilitate the hydrogen generation.

  12. Lanthanide extraction with 2,5-dimethyl-2-hydroxyhexanoic acid

    International Nuclear Information System (INIS)

    Miller, J.H.

    1977-12-01

    This research is concerned with the solvent extraction into chloroform of the lanthanides, using 2,5-dimethyl-2-hydroxyhexanoic acid (DMHHA). This acid is the first α-hydroxy aliphatic acid to be studied as an extracting agent for the lanthanides. The chloroform-water DMHHA partition constant was determined to be 1.0 (at 0.1 M ionic strength and 25 0 C). The acid dimerizes in chloroform with a constant of 56. The light lanthanides can be extracted into chloroform by forming complexes with the DMHHA anions. The extracted metal species is highly aggregated. This extraction has a solubility limit which increases with the addition of unionized acid. The resultant extract is also highly aggregated. At unionized acid-to-metal ratios greater than one, extractions first occur followed by the slow precipitation of the lanthanide. At the tracer level, neodymium is extracted primarily as NdA 3 (HA) 5 and (NdA 3 ) 2 (HA)/sub q/. Very small amounts of (NdA 3 ) 2 and other metal aggregates are also present. The heavy lanthanides do not extract from solutions of DMHHA and its potassium salt, but form aqueous emulsions and precipitates. In the presence of the organic soluble tetrabutylammonium ion the heavy lanthanides can be extracted, presumably as ion pairs. The stability constants of the light lanthanides and DMHHA were determined. The separation factors obtained from DMHHA extractions of the light lanthanides were also investigated and found to be comparable to those obtained employing normal aliphatic carboxylic acid

  13. Molybdenum (VI) binded to humic and nitrohumic acid models in aqueous solutions salicylic, 3-nitrosalicylic, 5-nitrosalicylic and 3,5 dinitrosalicylic acids, Part 2

    International Nuclear Information System (INIS)

    Merce, Ana Lucia R.; Lopes, Priscilla P.; Mangricha, Antonio S.

    2006-01-01

    In this work electrochemical and Ultraviolet-Visible studies were performed in solutions of salicylic acid models of humic and nitrohumic acids, a laboratory artifact, and molybdenum in order to determine the affinity of these models towards the metal ion. Molybdenum, which plays a very important role in the soil chemistry, and together with humic substances, impart fertility to soil and water and is a key element in the activity of nitrogenase. The obtained results showed that at least one complexed species is present at the pH range of 6.3 to 8.0, even for the less basic chosen models, the nitrosalicylic acids. Previous study showed that phthalic and nitrophthalic, also humic and nitrohumic acids model compounds, presented complexed species with molybdenum only till pH 6.5. The calculated formation constants showed that the substitution of the nitro group in the orto position was less favoured than in the para substitution, probably due to a steric hindrance in the former, which was clearly seen in the double substituted salicylic nitro derivative. The cyclic voltammetry as well as the Ultraviolet-Visible obtained spectra were able to show that the chemistry of molybdenum in aqueous solutions as the pH is increased is very complex, and the molybdate stops acting as an anion only after pH around 4, when it finally becomes a cation MoO 2 2+ (M). (author)

  14. Synthesis and characterization of PVP/ Sb2S3 composite films

    International Nuclear Information System (INIS)

    Salema, A.M.; Marzouka, S.; Khafagib, M.G.

    2005-01-01

    Polyvinyl pyrrolidone has been successfully used as a matrix to embedded Sb 2 S 3 nanoparticles. PVP thin films containing 5-25 wt % Sb 2 S 3 were deposited onto glass substrates by dip coating. X-ray diffraction spectra revealed that Sb 2 S 3 crystals depressed as nanometer-sized in the PVP matrix and the result was confirmed via scanning electron microscopy. The transmission and reflection spectra of the prepared samples were recorded in the wavelength optical range 250-2500 nm. The transmission spectra of the films show that transmission valley shifts toward higher wavelengths with increasing Sb 2 S 3 wt %. The optical constants of the deposited films, such as refractive index, extinction coefficient were obtained using the transmission and reflection data. The spectral behaviour of the loss factor, as well as the real and imaginary parts of the optical conductivity were also presented

  15. Asymmetric synthesis of allylic sulfonic acids: enantio- and regioselective iridium-catalyzed allylations of Na2SO3.

    Science.gov (United States)

    Liu, Wei; Zhao, Xiao-ming; Zhang, Hong-bo; Zhang, Liang; Zhao, Ming-zhu

    2014-12-15

    An enantioselective allylation reaction of allylic carbonates with sodium sulfite (Na2 SO3 ) catalyzed by Ir complex was accomplished, providing allylic sulfonic acids in good to excellent yields with a high level of enantio- and regioselectivities. (R)-2-Phenyl-2-sulfoacetic acid, a key intermediate for the synthesis of Cefsulodin and Sulbenicillin, was synthesized as well. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Spectrophotometric study into complexing of vanadium(3) with salicylic acid derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Dolgorev, A V; Serikov, Yu A; Zolotavin, V L

    1977-03-01

    Complexing of vanadium (3) with 5 amino-salicylic acid and amide of salicylhydroxamic acid has been studied. It has been shown that in acidic medium V/sup 3 +/ forms yellow complexes of the composition 1:1 with instability constants 2.2x10/sup -19/, 7.8x10/sup -11/, and 2.2x10/sup -12/, respectively. Complexes of V/sup 3 +/ with derivatives of salicylic acid can be used for determining V(3) content in the presence of V(4).

  17. Quantum confinement of Bi2S3 in glass with magnetic behavior

    Directory of Open Access Journals (Sweden)

    Rajendra P. Panmand

    2013-02-01

    Full Text Available The novel Bi2S3 quantum dots (QDs glass nanosystems with unique magnetic properties have been investigated. The monodispersed QDs of size in the range of 3 to 15 nm were grown in the glass matrix. The optical study of these nanosystems clearly demonstrated the size quantization effect resulting in a pronounced band gap variation with QD size. The magnetic properties of the pristine glass and the Bi2S3 QD glass nanosystems were investigated by VSM and SQUID magnetometer. The pristine glass did not show any ferromagnetism while the Bi2S3 glass nanosystems showed significant and reproducible ferromagnetism. We also investigated the effect of the size of Bi2S3 QDs on the magnetic properties. The saturation magnetization for the 15 nm QD glass-nanosystem (124 memu/g was observed to be higher as compared to the 3nm QD glass nanosystem (58.2 memu/g. The SQUID measurement gave the excellent hysteresis up to 300K. Surprisingly, the bulk Bi2S3 powder is diamagnetic in nature but Bi2S3 quantum dots glass nanosystem showed the ferromagnetic behavior for the first time. The investigated novel QD glass-nanosystem may have a potential application in spintronic devices and most importantly, this nanosystem can be fabricated in any usable shape as per the device requirement.

  18. Time-resolved fluorescence sensing of N-acetyl amino acids, nucleobases, nucleotides and DNA by the luminescent Tb (III) - 8-alkyl-2-oxo-2H-chromene-3-carbaldehyde probe

    Energy Technology Data Exchange (ETDEWEB)

    Azab, Hassan A. [Chemistry Department, Faculty of Science, Suez Canal University, 41522 Ismailia (Egypt); Khairy, Gasser M., E-mail: gasser_chemist@yahoo.com [Chemistry Department, Faculty of Science and Arts, Aljouf University, P.O. Box # 2014, Skaka 41421 (Saudi Arabia); Chemistry Department, Faculty of Science, Suez Canal University, 41522 Ismailia (Egypt); Abd El-Ghany, N.; Ahmed, Marwa A. [Chemistry Department, Faculty of Science, Suez Canal University, El-Arish (Egypt)

    2016-08-15

    A time-resolved (gated) luminescence-based method for the detection of some of N-acetyl amino acids, nucleobases, nucleotides, and DNA using terbium- 8-alkyl-2-oxo-2H-chromene-3-carbaldehyde (AOCC) complex in 1:2 metal: ligand ratio in microtiterplate format has been evolved. The linear range for determination of the selected biomolecules is 0.1–1.0 µM. The detection limit was in the range of 0.0371–0.106 µM. The thermodynamic parameters, and binding constants (K) of N-acetyl amino acids, nucleobases, nucleotides with Tb (III) –(AOCC) {sub 2} complex were calculated. Positive and negative values of entropy (ΔS) and enthalpy (ΔH) changes for Tb (III) –(AOCC){sub 2}– N-acetyl amino acids, nucleobases or nucleotides ternary complexes were evaluated. Selectivity of Tb (III) -complex towards different biomolecules has been studied using ratiometric methods of analysis by comparison of biomolecules binding affinities for Tb (III) -complex. Interaction of Tb (III) complex with DNA has been studied.

  19. Time-resolved fluorescence sensing of N-acetyl amino acids, nucleobases, nucleotides and DNA by the luminescent Tb (III) - 8-alkyl-2-oxo-2H-chromene-3-carbaldehyde probe

    International Nuclear Information System (INIS)

    Azab, Hassan A.; Khairy, Gasser M.; Abd El-Ghany, N.; Ahmed, Marwa A.

    2016-01-01

    A time-resolved (gated) luminescence-based method for the detection of some of N-acetyl amino acids, nucleobases, nucleotides, and DNA using terbium- 8-alkyl-2-oxo-2H-chromene-3-carbaldehyde (AOCC) complex in 1:2 metal: ligand ratio in microtiterplate format has been evolved. The linear range for determination of the selected biomolecules is 0.1–1.0 µM. The detection limit was in the range of 0.0371–0.106 µM. The thermodynamic parameters, and binding constants (K) of N-acetyl amino acids, nucleobases, nucleotides with Tb (III) –(AOCC) 2 complex were calculated. Positive and negative values of entropy (ΔS) and enthalpy (ΔH) changes for Tb (III) –(AOCC) 2 – N-acetyl amino acids, nucleobases or nucleotides ternary complexes were evaluated. Selectivity of Tb (III) -complex towards different biomolecules has been studied using ratiometric methods of analysis by comparison of biomolecules binding affinities for Tb (III) -complex. Interaction of Tb (III) complex with DNA has been studied.

  20. Synthesis and investigation of the physicochemical properties of 2-(5-((theophylline-7'-ylmethyl-4-phenyl-4H-1,2,4-triazole-3-ylthio-acetic acid salts

    Directory of Open Access Journals (Sweden)

    A. S. Gotsulya

    2014-02-01

    Full Text Available Introduction. In last decades considerable interest to the search of biologically active compounds in series of azole derivatives is indicated. This is mainly connected with the successful use of several drugs with heterocyclic system in the structure. Analysis of the pharmacological properties of heterocyclic nitrogen–containing compounds of the known groups let us to suggest, that the triazole substituent is an important pharmacophore fragment, responsible for the availability of diverse physiological activity. In addition, it causes a little toxicity. Considerable attention belongs to synthesis and research of the biological activity of 1,2,4-triazoles derivatives. The great importance also has research of the influence of heterocyclic fragments of different nature in combination in one molecule on the activity of the synthesized compounds. Like different synthons in the structure of 1,2,4-triazoles in various kinds of biological activity of the reaction products with an aim of new and highly efficient low-toxicity compounds reception. The aim of work was to study synthesis and properties of substances among salts of 2-(5-((theophylline-7'-ylmethyle-4-phenyle-4Н-1,2,4-triazole-3-ylthioacetate acid. Materials and methods of the research. In the process as a starting material for reception of new series of compounds theophylline has been chosen. It is important to note, that by the diversity and strength of pharmacological effects, which appears, this structure takes its rightful place among heterocyclic compounds. Through the series of the successive stages 4-phenyle-5-(1',3'-dimethylxantine-7'-ylmethyle-1,2,4-triazole-3-thiol was obtained from the theophylline. Research of the physico-chemical properties of the received compounds conducted according to methods, described in the State Pharmacopoeia of Ukraine. open capillary method, elemental analysis (Elementar Vario L cube (CHNS. 1H NMR spectra of compounds were recorded with a