ABSTRACT
Dihydrochelerythrine was isolated from the ethanol extract of Corydalis yanhusuo by chromatographic and recrystallization techniques. To our knowledge, this is the first report that dihydrochelerythrine was found to be unstable. The NMR, HPLC, and LC-MS were applied to monitor the structural conversion process of dihydrochelerythrine. The results showed that when dissolved in polar deuteration solvent (e.g., DMSO-₆ & MeOD), dihydrochelerythrine is directly converted to chelerythrine gradually. However, if used non-polar reagent (e.g.,CD₂Cl₂), the sample of dihydrochelerythrine undergoes the formation of pseudobase, chelerythrine, and bimolecular ether then followed by oxidation to oxychelerythrine as the major final product. Which leads to this phenomenon maybe is that the C-6 in dihydrochelerythrine is highly reactive to nucleophiles, and is easily converted to different derivatives in different solvents attributed to the solvent effect. This finding will contribute to the extraction and isolation, bioactivity screening, and quality evaluation of medicinal materials containing dihydrochelerythrine and other similar derivatives.
ABSTRACT
Objective To exPlore the effect of samPle_solVent comPositions on the determination of AstragaliⅣby high Performance liquid chromatograPh_ eVaPoratiVe light scattering detector ( HPLC_ELSD ) . Methods Radix astragali and ganduqing granules serVed as samPles. Methanol,90%methanol,80%methanol,70%methanol,32%acetonitrile,15%acetonitrile, and water were samPle solVents. HPLC_ELSD was used to determine content of astragalosideⅣ. Results The results showed that the 90%methanol solution was an aPProPriate samPle solVent with good system suitability,Precision,accuracy,and,linearity etc. . Conclusion This method benefits the quality control of astragalosideⅣin Radix astragali and agents containing Radix astragali.
ABSTRACT
Studies on the influence of heavy water on mitochondrial respiration and oxidative phosphorylation revealed that both isotope and solvent effects, may be responsible for the observed changes. Although the two types of effects could not be totally delineated from each other by the experimental approaches employed, the isotope effect appeared to be primarily responsible for the uncoupling of oxidative phosphorylation, while the inhibition of respiration in the presence of ADP (State 3 respiration) could be a manifestation of the solvent effect.