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Objective To study the anti-oxidation properties of Zn2+-quercetin complexes .Methods The binding stoi-chiometric ratios and the binding constant of Zn2+ to quercetin were measured with UV-Vis spectroscopy .The binding sites on quercetin were determined via1 H NMR spectroscopy .The antioxidant activities of Zn2+-quercetin complexes were compared to quercetin by scavenging DPPH radical method .The binding ratio of Zn2+ to quercetin depends on neutralization of phenol groups of quercetin .Results The binding ratio of Zn2+ to quercetin is 1:2 when less than two OH groups were deprotonated . The binding ratio is 1:1 when more than three OH groups were deprotonated .The apparent binding constant is 2 .42 × 106 M -1 for the 1:1 Zn2+-quercetin complex .The 3′-OH and 4′-OH of quercetin are involved in the Zn2+ binding .The scavenging DPPH radical activity of Zn2+-quercetin complex is 2 .3 times of quercetin .Conclusion These results provide a new insight to expand applications of this traditional Chinese medicine .
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ObjectiveTo study the metabolite features of acute necrotizing pancreatitis (ANP) and chronic pancreatitis (CP) in rats.MethodsA total of 22 Wistar rats were divided into ANP group (n =7 ),CP group (n =6) and the control group (n =9).ANP model was induced peritoneous injection of 20％ Larginine,and the rats were sacrificed 12 hours later.CP model was induced by intravenously injection of DBTC (8 mg/kg body weight),and the rats were sacrificed after 2 months.The rats in the control group received same amount of saline.Serum amylase was determined and pancreatic tissues were pathologically examined.Metabolic changes of pancreatic tissues in vitro were studied by high resolution magic angle spinning nuclear magnetic resonance (MAS NMR ),and analyzed by using principal components analysis (PCA).Characteristic metabolites of ANP and CP were compared. Results Compared with the control group,increased leucine,iso-leucine and valine levels were observed in ANP group,however,the opposite trends were observed in CP group.Phosphocholine,glycerophosphocholine,choline levels were increased and fatty acids,lactate,betaine,glycine levels were decreased in both ANP and CP groups.The lipid content in CP group were significantly higher than that in ANP group and the increased taurine was only observed in CP group. Conclusions There were obvious metabolic features in pancreatic tissue in rats with pancreatitis disorders,and the increased taurine could be used as biomarker to discriminate ANP and CP.
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Objective To observe the metabolic characteristics of an experimental model of chronic pancreatitis,and to investigate its role in the grading of chronic pancreatitis.Methods Thirty-six Wistar rats were injected with dibutyltin chloride (DBTC) solution (8mg/kg) via the tail vein to establish the experimental model of chronic pancreatitis.The 36 rats were divided into 6 groups with 6 rats in each group.On0,7,14,21,28,35 days after modeling,rats was sacrificed and pancreatic tissue of the rats was harvested,and a small part was used for pathologic study,the majority part was kept at-80℃ under liquid nitrogen freezing.Metabolites of pancreatic tissue were determined by high-resolution magic angle spinning nuclear magnetic resonance spectroscopic (HR-MAS NMRS).On the basis of the abnormal structure,tubular complexes,gland atrophy,fibrosis,edema and inflammatory cell infiltration,chronic pancreatitis was graded.Results Pathologic study showed the severity of chronic pancreatitis gradually increased with time after modeling.The 7th,14th day after modeling,the pancreatic change was mild chronic pancreatitis; the 21st,28th,35th day,the pancreatic change was changed into severe chronic pancreatitis.Principal component analysis of HR-MAS NMRS showed that the betaine (Bet) and choline ( Cho)-contained components were significantly increased in severe chronic pancreatitis; while aspartate (Asp),lactate (Lac),isoleucine/leucine/valine (I/L/V) and fatty acid (FA) were significantly reduced when compared with those in mild chronic pancreatitis and normal pancreatic tissue.There was no significant difference in the amount of metabolic characteristics between mild chronic pancreatitis and normal pancreatic tissue.Conclusions HRMAS NMRS was helpful in distinguishing the severe chronic pancreatitis from mild chronic pancreatitis.
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Objective: To establish capillary zone electrophoresis method for determination of sildenafil citrate (Viagra) content in its troche. Methods： Using tetrandrine as internal standard(IS), the electrophoretic separation was achieved with 25 mmol/L borate (pH=7.89) running buffer. And a voltage of 14 kV was applied to the 40 cm×75 μm(i.d) capillary. The analytes were introduced into capillary by siphon (1 s) and determined with on-column monitoring at 214 nm. Results：The determination could be completed within 4 min and the minimum concentration of detection was 5 μg/ml.The analytical results of sildenafil citrate samples demonstrated a good linear relationship within the range of 24-480 μg/ml.The relative standard deviations (RSD) of intra-day was less than 1.58% and that of inter-day was less than 2.46%.The present recoveries were between 95%-105％. Conclusion：The CZE method is accurate, simple, rapid and reliable, so it can be applied to the determination of sildenafil citrate content.
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Objective: To investigate the chemical constituents of Erigeron breviscapus (Vant.) Hand. Mazz. Methods: The CHCl 3 extract was isolated and purified with the silica gel column chromatography. The compounds were determined on the basis of spectral analysis(IR, MS, 1HNMR and 13 CNMR). Results: Six compounds were isolated and the structures were identified as 3, 4 dihydroxy phenyl acrylic acid (Ⅶ), ? methoxy ? pyranone (Ⅷ), stigmasterol (Ⅸ), stigmasterol 3 O ? D glucopyranoside(Ⅹ), ? sistosterol (Ⅺ), ? sistosterol 3 O ? D glucopyranoside (ⅩⅡ). Conclusion: Compounds Ⅶ,Ⅷ,Ⅺ,ⅩⅡ are isolated from this plant for the first time. [