Chemical constituents from rhizome of Menispermum dauricum and their anti-hypoxic activities / 中国中药杂志

To study the chemical constituents from the rhizome of Menispermum dauricum,fifteen compounds,N-methylcorydaldine( 1),thalifoline( 2),stepholidine( 3),acutumine( 4),daurisoline( 5),acutumidine( 6),dauricicoline( 7),bianfugecine( 8),6-O-demethylmenisporphine( 9),bianfugedine( 10),dauricoside( 11),eleutheroside D( 12),aristolactone( 13),aristoloterpenateⅠ( 14) and aristolochic acid( 15) were isolated from 75% ethanol extract of Menispermi Rhizoma by using thin layer chromatography and column chromatography methods. Their structures were identified based on their physicochemical properties and spectral data. Among them,compounds 12-15 were obtained from the genus Menispermum for the first time. Six alkaloids with higher contents were subjected to evaluate the anti-hypoxic activities by using MTT method. As a result,six alkaloids exhibited significant anti-hypoxia activities.

Determination of R(-)- isomer in repaglinide tablets by capillary electrophoresis / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To develop a capillary electrophoresis system for enantiomeric impurity test of repaglinide.</p><p><b>METHODS</b>An uncoated fused silica capillary (50 μm×50 cm, with an effective length of 41 cm) was used. The running buffer was composed of 30 mmol/L NaH2PO4 and 5 mg/ml carboxymethyl-β-cyclodextrin(pH 3.5).</p><p><b>RESULTS</b>Linear range was 2.00-80.00 μg/ml (correlation coefficient was 0.9993). The average recovery rate was 92.5% to 105.0%.</p><p><b>CONCLUSION</b>The method is simple, accurate and sensitive and it can be used for determination of enantiomeric impurities in repaglinide tablet.</p>

Determination of enantiomeric impurity in levocetirizine tablets by capillary electrophoresis / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To determine enantiomeric impurity in levocetirizine tablets by using capillary electrophoresis.</p><p><b>METHODS</b>The effects of pH and the concentrations of sulfated-Β-cyclodextrin (S-Β-CD) and buffer salt on chiral resolution were examined with S-Β-CD as chiral selector.</p><p><b>RESULTS</b>A good enantioseparation of cetirizine was achieved with 30 mmol/L NaH2PO4 buffer solution (pH 7.0) containing 20 g/L of S-Β-CD.</p><p><b>CONCLUSION</b>The method developed in the study is sensitive and reliable for determination of enantiomeric impurity in levocetirizine tablets.</p>

Simultaneous determination of four components in Hedyotis diffusa oral solution by reversed-phase HPLC / 中国中药杂志

<p><b>OBJECTIVE</b>A new method for simultaneous determination of four methyl-3, 4-dihydroxybenzoate ( I ), P-coumaric acid (II), ferulaic acid (III) and E-6-O-P-coumaroyl scandoside methyl ester (IV) in Hedyotis diffusa oral solution by reversed-phase HPLC was developed.</p><p><b>METHOD</b>The separation was performed on a Diamonsil C18 column (4.6 mm x 250 mm, 5 microm) with gradient elution. A-acetonitrile, B-methonal-water-glacial acetic acid (5: 95: 0.25), 0-20 min, 1% -16% A; 2042 min, 16% A; 42-46 min, 16%-20%A; 46-65 min, 20% A. The UV detection was set at 265 nm; flow rate 1.0 mL x min(-1).</p><p><b>RESULT</b>There was good linearity between the peak area and concentration at the ranges of 2.1-105 (r = 0.999 8), 3.5-175 (r = 0.999 8), 1.72-86 (r = 0.999 9), 4.0-200 mg x L(-1) (r = 1.000 0) for I, II, III and IV respectively. The average recoveries of I, II, III and IV were 99.9%, 97.9%, 98.6% and 98.1%.</p><p><b>CONCLUSION</b>The method is rapid, simple and accurate, and it can be used for the evaluation of H. diffusa oral solution.</p>