ABSTRACT
Alismatis Rhizoma(AR)is widely used in Chinese medicine,and its major bioactive components,tri-terpenes,reportedly possess various pharmacological activities.Therefore,it is very important to study the metabolism of triterpenes in vivo.However,the metabolism of AR triterpene extract has not been comprehensively elucidated due to its complex chemical components and metabolic pathways.In this study,an ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry method,which was based on the characteristic ions from an established database of known triterpenes,was used to analyze the major metabolites in rats following the oral administration of Alismatis Rhizoma extracts(ARE).As a result,a total of 233 constituents,with 85 prototype compounds and 148 metabo-lites,were identified for the first time.Hydrogenation,oxidation,sulfate and glucuronidation conjugation were the major metabolic pathways for triterpenes in AR.In addition,the mutual in vivo transformation of known ARE triterpenes was discovered and confirmed for the first time.Those results provide comprehensive insights into the metabolism of AR in vivo,which will be useful for future studies on its pharmacodynamics and pharmacokinetics.Moreover,this established strategy may be useful in meta-bolic studies of similar compounds.
ABSTRACT
Objective:To explore the interaction between gossypol and human serum albumin ( HSA) . Methods:The interaction of gossypol and HSA under physiological conditions was studied by fluorescence spectroscopy, and the molecular docking software was used to simulate the interaction. Results:The binding constant of gossypol and HSA at 293K and 303K was 2. 390 6 × 105 L·mol-1 and 3. 576 8 × 103 L·mol-1 , respectively. There was one binding site on HSA for gossypol. Hydrogen bond and Van Der Waals inter-actions were involved in the binding process. The binding of gossypol and HAS was closer to tyrosine residue in HSA. The molecular simulation analysis verified the above results. Conclusion: The gossypol-induced fluorescence quenching of HSA belongs to a static quenching procedure.