Aim To study the chemical constituents of the root and rhizome of Rheum tanguticum Maxim. ex Balf. Methods Chemical constituents were isolated and purified by many chromatographic methods, and their structures were el...Aim To study the chemical constituents of the root and rhizome of Rheum tanguticum Maxim. ex Balf. Methods Chemical constituents were isolated and purified by many chromatographic methods, and their structures were elucidated by MS, NMR, and others. Results Twenty compounds were isolated and their structures were identified as β-sitosterol, chrysophanol, aloe-emodin, physcion, rhein, emodin, etc. Conclusion Among these compounds, 4-(4′-hydroxyphenyl)-2-butanone, 4-(4′-hydroxyphenyl)-2-butanone-4′-O-β-D-(2″-...展开更多
Previously, we had characterized several structurally interesting brominated phenols from the marine red alga Symphyocladia latiuscula collected from various sites. However, Phytochemical investigations on this specie...Previously, we had characterized several structurally interesting brominated phenols from the marine red alga Symphyocladia latiuscula collected from various sites. However, Phytochemical investigations on this species collected from the Weihai coastline of Shandong Province remains blank. Therefore, we characterized the chemical constituents of individuals of this species collected from the region. Eight bromophenols were isolated and identified. Using detailed spectroscopic techniques and comparisons with published data, these compounds were identified as 2,3-dibromo-4,5-dihydroxybenzyl methyl ether (1), 3,5-dibromo-4-hydroxybenzoic acid (2), 2,3,6-tribromo-4,5-dihydroxymethylbenzene (3), 2,3,6-tribromo-4,5-dihydroxybenzaldehyde (4), 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether (5), bis(2,3,6-tribromo-4,5-dihydroxyphenyl)methane (6), 1,2-bis(2,3,6-tribromo-4,5-dihydroxyphenyl)-ethane (7), and 1-(2,3,6-tribromo-4,5-dihydroxybenzyl)-pyrrolidin-2-one (8). Among these compounds, 1 and 2 were isolated for the first time from S. latiuscula. Each compound was evaluated on the ability to inhibit protein tyrosine phosphatase 1B (PTP1B), which is a potential therapeutic target in the treatment of type 2 diabetes. Bromophenols 5, 6, and 7 showed strong activities with IC50 values of 3.9, 4.3, and 3.5 μmol/L, respectively. This study provides further evidence that bromophenols are predominant among the chemical constituents of Symphyocladia, and that some of these compounds may be candidates for the development of anti-diabetes drugs.展开更多
Adopting Poly（ethylene glycol） adipate Dilpoly- （ethylene glycol）] adipate polydiglycol adipate glycol （PDAG）, 1,4-butanediol （BDO）, hydroxy silicone oil, methylene diphenyl diisocyanate （MDI） as the raw mat...Adopting Poly（ethylene glycol） adipate Dilpoly- （ethylene glycol）] adipate polydiglycol adipate glycol （PDAG）, 1,4-butanediol （BDO）, hydroxy silicone oil, methylene diphenyl diisocyanate （MDI） as the raw material, a new polyurethane elastic body can be made through prepolymerization. After measurement of the moisture permeability, adsorption quantity and mechanical properties of the membrane made with the elastic body, we also proofed its formula by infrared spectroscopy. The result showed that the moisture permeability of the membrane, with a certain intelligent thermotropic quality, will increase by 3 to 4 times when the temperature is between 25℃-45℃.展开更多
In the current study, we established and validated a simple and sensitive liquid chromatography-tandem mass spectrometric method for the determination of 21-hydroxy deflazacort in nude mice plasma, and such a method w...In the current study, we established and validated a simple and sensitive liquid chromatography-tandem mass spectrometric method for the determination of 21-hydroxy deflazacort in nude mice plasma, and such a method was applied to a pharmacokinetic study. Using betamethasone as the internal standard, the plasma samples were pre-treated by precipitation with acetonitrile and then analyzed on a reversed-phase C18 column （50 mm×2 mm, 5 μm） with a mobile phase consisting of acetonitrile and 4.0 mM ammonium formate （pH was adjusted to 3.5 with formic acid （40：60, v/v））. The analyte was detected by a triple quadrupole tandem mass spectrometer using electrospray, and multiple reaction monitoring was employed to select 21-hydroxy deflazacort at m/z 400.2/124.0 and betamethasone at m/z 393.3/147.0 in the positive ion mode. The calibration curves were linear （r〉0.99） over the range of 0.5~,00 ng/mL. The intra- and inter-day precisions and accuracies were 4.5%-10.1% and -1.7%-10.7% respectively. This method was successfully applied to a preclinical administered with a single oral dose of 4 mg/kg deflazacort, and its pharmacokinetic study of deflazacort on female nude mice pharmacokinetics was characterized by a two-compartment model with first-order absorption.展开更多
基金Natural Research Foundation of Qinghai Province( No. 2004-N-103-02)
文摘Aim To study the chemical constituents of the root and rhizome of Rheum tanguticum Maxim. ex Balf. Methods Chemical constituents were isolated and purified by many chromatographic methods, and their structures were elucidated by MS, NMR, and others. Results Twenty compounds were isolated and their structures were identified as β-sitosterol, chrysophanol, aloe-emodin, physcion, rhein, emodin, etc. Conclusion Among these compounds, 4-(4′-hydroxyphenyl)-2-butanone, 4-(4′-hydroxyphenyl)-2-butanone-4′-O-β-D-(2″-...
基金Supported by the National Natural Science Foundation (No. 30530080)the Ministry of Science and Technology of China (Nos. 2007AA09Z402, 2007AA09Z403)the Department of Science and Technology of Shandong Province (No. 2006GG2205023)
文摘Previously, we had characterized several structurally interesting brominated phenols from the marine red alga Symphyocladia latiuscula collected from various sites. However, Phytochemical investigations on this species collected from the Weihai coastline of Shandong Province remains blank. Therefore, we characterized the chemical constituents of individuals of this species collected from the region. Eight bromophenols were isolated and identified. Using detailed spectroscopic techniques and comparisons with published data, these compounds were identified as 2,3-dibromo-4,5-dihydroxybenzyl methyl ether (1), 3,5-dibromo-4-hydroxybenzoic acid (2), 2,3,6-tribromo-4,5-dihydroxymethylbenzene (3), 2,3,6-tribromo-4,5-dihydroxybenzaldehyde (4), 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether (5), bis(2,3,6-tribromo-4,5-dihydroxyphenyl)methane (6), 1,2-bis(2,3,6-tribromo-4,5-dihydroxyphenyl)-ethane (7), and 1-(2,3,6-tribromo-4,5-dihydroxybenzyl)-pyrrolidin-2-one (8). Among these compounds, 1 and 2 were isolated for the first time from S. latiuscula. Each compound was evaluated on the ability to inhibit protein tyrosine phosphatase 1B (PTP1B), which is a potential therapeutic target in the treatment of type 2 diabetes. Bromophenols 5, 6, and 7 showed strong activities with IC50 values of 3.9, 4.3, and 3.5 μmol/L, respectively. This study provides further evidence that bromophenols are predominant among the chemical constituents of Symphyocladia, and that some of these compounds may be candidates for the development of anti-diabetes drugs.
基金Acknowledgments： This work was supported in part by the National Natural Science Foundation of China （No. 20504023）.
文摘Adopting Poly（ethylene glycol） adipate Dilpoly- （ethylene glycol）] adipate polydiglycol adipate glycol （PDAG）, 1,4-butanediol （BDO）, hydroxy silicone oil, methylene diphenyl diisocyanate （MDI） as the raw material, a new polyurethane elastic body can be made through prepolymerization. After measurement of the moisture permeability, adsorption quantity and mechanical properties of the membrane made with the elastic body, we also proofed its formula by infrared spectroscopy. The result showed that the moisture permeability of the membrane, with a certain intelligent thermotropic quality, will increase by 3 to 4 times when the temperature is between 25℃-45℃.
基金National Natural Science Foundation of China(NSFC,Grant No.81673500)
文摘In the current study, we established and validated a simple and sensitive liquid chromatography-tandem mass spectrometric method for the determination of 21-hydroxy deflazacort in nude mice plasma, and such a method was applied to a pharmacokinetic study. Using betamethasone as the internal standard, the plasma samples were pre-treated by precipitation with acetonitrile and then analyzed on a reversed-phase C18 column （50 mm×2 mm, 5 μm） with a mobile phase consisting of acetonitrile and 4.0 mM ammonium formate （pH was adjusted to 3.5 with formic acid （40：60, v/v））. The analyte was detected by a triple quadrupole tandem mass spectrometer using electrospray, and multiple reaction monitoring was employed to select 21-hydroxy deflazacort at m/z 400.2/124.0 and betamethasone at m/z 393.3/147.0 in the positive ion mode. The calibration curves were linear （r〉0.99） over the range of 0.5~,00 ng/mL. The intra- and inter-day precisions and accuracies were 4.5%-10.1% and -1.7%-10.7% respectively. This method was successfully applied to a preclinical administered with a single oral dose of 4 mg/kg deflazacort, and its pharmacokinetic study of deflazacort on female nude mice pharmacokinetics was characterized by a two-compartment model with first-order absorption.
