AIM: Peroxynitrite (ONOO-) is a powerful oxidant shown to damage membranes. In the present study, the effect of taurine on changes of liver plasma membrane Na+, K+-ATPase induced by ONOO- was investigated. METHODS: Li...AIM: Peroxynitrite (ONOO-) is a powerful oxidant shown to damage membranes. In the present study, the effect of taurine on changes of liver plasma membrane Na+, K+-ATPase induced by ONOO- was investigated. METHODS: Liver plasma membrane was exposed toONOO-with or without taurine. Na+, K+-ATPase activity and lipid peroxidation as thiobarbituric acid reactive substances (TBARS) levels were measured.RESULTS: Different concentrations of ONOO- (100, 200,500, and 1 000 μmol/L) were found to decrease liver plasma membrane Na+, K+-ATPase activity significantly. The depletion of enzyme activity was not concentration dependent. Effects of different concentrations of taurine on liver plasma membrane Na+, K+-ATPase activity were also measured. Taurine did not cause any increase in enzyme activity. When plasma membranes were treated with 200 μmol/L ONOO- with different concentrations of taurine, a restoring effect of taurine on enzyme activity was observed. TBARS levels were also measured and taurine was found to decrease the elevated values. CONCLUSION: Taurine is observed to act as an antioxidant of ONOO-to decrease lipid peroxidation and thus affect liver plasma membrane Na+, K+-ATPase by restoring its activity.展开更多
The effects of various salinity fluctuation amplitudes （2, 4, 6 and 8） on the growth, osmolarity, Na＋-K＋-ATPase activity and Hsp70 of juvenile Fenneropenaeus chinensis cultured in seawater with a salinity of 20 we...The effects of various salinity fluctuation amplitudes （2, 4, 6 and 8） on the growth, osmolarity, Na＋-K＋-ATPase activity and Hsp70 of juvenile Fenneropenaeus chinensis cultured in seawater with a salinity of 20 were studied. The results show that weight gain in the salinity fluctuation treatments was better than that in control; in particular, the weight gain of treatments S4 and SO, at 231.8% and 196.3%, respectively, was significantly different （P〈0.05）. The hemolymph osmolarity of treatments SO, S2, S4, S6 and S8 was 635.4, 630.8, 623.6, 614.4 and 600.3 mOsm/kg, respectively, and decreased with increasing salinity fluctuation amplitude. The level of Na＋-K＋-ATPase activity in gills ofE chinensis was higher than that in hepatopancreas, but there were no significant differences among all treatments, either in gills or hepatopancreas （P〉0.05）. The relative level of Hsp70 in treatment $4 was 48.4% and 40.4% higher than control in muscle and eyestalks, respectively, with the highest values being recorded under a salinity fluctuation amplitude of 4.展开更多
The title compound △14,15-anhydro-24-thiocarbonylbufalin （1） was prepared by the reaction of natural product bufalin with Lawesson reagent. The crystal structure of 1, C24H3002S＇C24H3002S, was determined by single...The title compound △14,15-anhydro-24-thiocarbonylbufalin （1） was prepared by the reaction of natural product bufalin with Lawesson reagent. The crystal structure of 1, C24H3002S＇C24H3002S, was determined by single-crystal X-ray diffraction analysis. It belongs to monoclinic, space group C2, with a = 30.9845（2）, b = 6.8036（3）, c = 22.5791（15）/k, V= 4241.7（4） A3, Mr = 384.21, Z = 4, Dc= 1.204 g/cm3,μ = 1.463 mm4, F（000） = 1664, S = 1.064, R = 0.0487 and wR = 0.0645 for 4683 unique reflections, of which 3757 were observed （I 〉 2σ（/））. The asymmetric unit contains two independent molecules （ⅠandⅡ）, which are closely similar to each other except for the orientation of the lactone ring. Both conformations of I and II are in good agreement with the solution structure in methanol as indicated by 1H-NMR analysis. Due to the presence of heavy atom sulfur in the molecules, the final refinement resulted in a small Flack parameter 0.02（3）, permitting the assignments of the absolute configuration. In the solid state, intermolecular hydrogen bonds involving thiocarbonyl group in the lactone moiety and the hydroxyl groups in the steroid moiety ester linked adjacent molecules into a three-dimensional network. Compound 1 showed weak inhibition on Na＋/K＋-ATPase in contrast to the strong inhibitory activity of the parent compound bufalin, suggesting that the carbonyl group in lactone moiety and the hydroxyl group atC-14 play important roles for the inhibition of Na＋/K＊-ATPase.展开更多
The title compound 1β-hydroxydigitoxigenin（1） was isolated from the ethanol extract of the roots of Streptocaulon juventas. The crystal structure of 1, C23H34O5·H2O, was determined by Synchrotron X-ray diffrac...The title compound 1β-hydroxydigitoxigenin（1） was isolated from the ethanol extract of the roots of Streptocaulon juventas. The crystal structure of 1, C23H34O5·H2O, was determined by Synchrotron X-ray diffraction analysis due to small crystal size（0.14 mm × 0.04 mm × 0.01 mm）. The crystal belongs to monoclinic, space group P21, with a = 7.6624（15）, b= 13.460（3）, c = 10.370（2） A, b = 92.40（3）°, V = 1068.6（4）A^3, Z = 2, Mr = 406.50, Dx = 1.263 g/cm^3, λ（synchrotron） = 1.2399 A, μ（synchrotron 1.23990） = 0.333 cm^-1, F（000） = 550, S = 1.059, R = 0.0625 and wR = 0.1687 for 4247 unique reflections, of which 3687 were observed（I 〉 2σ（I））. The asymmetric unit contains one independent molecule of 1 and one water molecule which are connected through hydrogen bonds. The conformation of 1 in crystalline state is in good agreement with the solution structure in methanol as indicated by ^1H-NMR analysis. The absolute configuration of 1 could be assigned by referring to the known configuration of the lactone ring at C（17b）. In the solid state, intermolecular hydrogen bonds involving carbonyl group in the lactone moiety and the hydroxyl groups in the steroid moiety ester linked adjacent molecules into a three-dimensional network. Compound 1 showed significant inhibition on Na^＋/K^＋-ATPase with an IC50 of 2.46 mM, which is stronger thiocarbonylbufalin but weaker than a close analog digitoxigenin, suggesting that a lactone ring is important and the substitution of a hydroxyl group at C（1） is not favored for the inhibition of Na^＋/K^＋-ATPase.展开更多
基金Supported by the Istanbul University Research Foundation,No.BYP-247/20082003
文摘AIM: Peroxynitrite (ONOO-) is a powerful oxidant shown to damage membranes. In the present study, the effect of taurine on changes of liver plasma membrane Na+, K+-ATPase induced by ONOO- was investigated. METHODS: Liver plasma membrane was exposed toONOO-with or without taurine. Na+, K+-ATPase activity and lipid peroxidation as thiobarbituric acid reactive substances (TBARS) levels were measured.RESULTS: Different concentrations of ONOO- (100, 200,500, and 1 000 μmol/L) were found to decrease liver plasma membrane Na+, K+-ATPase activity significantly. The depletion of enzyme activity was not concentration dependent. Effects of different concentrations of taurine on liver plasma membrane Na+, K+-ATPase activity were also measured. Taurine did not cause any increase in enzyme activity. When plasma membranes were treated with 200 μmol/L ONOO- with different concentrations of taurine, a restoring effect of taurine on enzyme activity was observed. TBARS levels were also measured and taurine was found to decrease the elevated values. CONCLUSION: Taurine is observed to act as an antioxidant of ONOO-to decrease lipid peroxidation and thus affect liver plasma membrane Na+, K+-ATPase by restoring its activity.
基金Supported by the National Natural Science Foundation of China (No. 30571441)Reward Research Foundation for Talented Young and Middle Aged Scientists of Shandong,China (No. 2006BS07002)National Key Technology Research and Development Program of China (No. 2006BAD09A07)
文摘The effects of various salinity fluctuation amplitudes （2, 4, 6 and 8） on the growth, osmolarity, Na＋-K＋-ATPase activity and Hsp70 of juvenile Fenneropenaeus chinensis cultured in seawater with a salinity of 20 were studied. The results show that weight gain in the salinity fluctuation treatments was better than that in control; in particular, the weight gain of treatments S4 and SO, at 231.8% and 196.3%, respectively, was significantly different （P〈0.05）. The hemolymph osmolarity of treatments SO, S2, S4, S6 and S8 was 635.4, 630.8, 623.6, 614.4 and 600.3 mOsm/kg, respectively, and decreased with increasing salinity fluctuation amplitude. The level of Na＋-K＋-ATPase activity in gills ofE chinensis was higher than that in hepatopancreas, but there were no significant differences among all treatments, either in gills or hepatopancreas （P〉0.05）. The relative level of Hsp70 in treatment $4 was 48.4% and 40.4% higher than control in muscle and eyestalks, respectively, with the highest values being recorded under a salinity fluctuation amplitude of 4.
基金supported by the National Natural Science Foundation of China(81102518)
文摘The title compound △14,15-anhydro-24-thiocarbonylbufalin （1） was prepared by the reaction of natural product bufalin with Lawesson reagent. The crystal structure of 1, C24H3002S＇C24H3002S, was determined by single-crystal X-ray diffraction analysis. It belongs to monoclinic, space group C2, with a = 30.9845（2）, b = 6.8036（3）, c = 22.5791（15）/k, V= 4241.7（4） A3, Mr = 384.21, Z = 4, Dc= 1.204 g/cm3,μ = 1.463 mm4, F（000） = 1664, S = 1.064, R = 0.0487 and wR = 0.0645 for 4683 unique reflections, of which 3757 were observed （I 〉 2σ（/））. The asymmetric unit contains two independent molecules （ⅠandⅡ）, which are closely similar to each other except for the orientation of the lactone ring. Both conformations of I and II are in good agreement with the solution structure in methanol as indicated by 1H-NMR analysis. Due to the presence of heavy atom sulfur in the molecules, the final refinement resulted in a small Flack parameter 0.02（3）, permitting the assignments of the absolute configuration. In the solid state, intermolecular hydrogen bonds involving thiocarbonyl group in the lactone moiety and the hydroxyl groups in the steroid moiety ester linked adjacent molecules into a three-dimensional network. Compound 1 showed weak inhibition on Na＋/K＋-ATPase in contrast to the strong inhibitory activity of the parent compound bufalin, suggesting that the carbonyl group in lactone moiety and the hydroxyl group atC-14 play important roles for the inhibition of Na＋/K＊-ATPase.
基金supported by the National Natural Science Foundation of China(No.81373956,81274064 and 81573315)the Fundamental Research Funds for the Central Universities(2015ZD010)the Priority Academic Program Development of Jiangsu Higher Education Institutions and Guangzhou Industry-University Collaborative Innovation Major Projects(201508030016)
文摘The title compound 1β-hydroxydigitoxigenin（1） was isolated from the ethanol extract of the roots of Streptocaulon juventas. The crystal structure of 1, C23H34O5·H2O, was determined by Synchrotron X-ray diffraction analysis due to small crystal size（0.14 mm × 0.04 mm × 0.01 mm）. The crystal belongs to monoclinic, space group P21, with a = 7.6624（15）, b= 13.460（3）, c = 10.370（2） A, b = 92.40（3）°, V = 1068.6（4）A^3, Z = 2, Mr = 406.50, Dx = 1.263 g/cm^3, λ（synchrotron） = 1.2399 A, μ（synchrotron 1.23990） = 0.333 cm^-1, F（000） = 550, S = 1.059, R = 0.0625 and wR = 0.1687 for 4247 unique reflections, of which 3687 were observed（I 〉 2σ（I））. The asymmetric unit contains one independent molecule of 1 and one water molecule which are connected through hydrogen bonds. The conformation of 1 in crystalline state is in good agreement with the solution structure in methanol as indicated by ^1H-NMR analysis. The absolute configuration of 1 could be assigned by referring to the known configuration of the lactone ring at C（17b）. In the solid state, intermolecular hydrogen bonds involving carbonyl group in the lactone moiety and the hydroxyl groups in the steroid moiety ester linked adjacent molecules into a three-dimensional network. Compound 1 showed significant inhibition on Na^＋/K^＋-ATPase with an IC50 of 2.46 mM, which is stronger thiocarbonylbufalin but weaker than a close analog digitoxigenin, suggesting that a lactone ring is important and the substitution of a hydroxyl group at C（1） is not favored for the inhibition of Na^＋/K^＋-ATPase.
