Assays based on high-performance liquid chromatography(HPLC)and liquid chromatography tandem mass spectrometry(LC–MSn)have been developed and validated for the determination and metabolite identification of the bidesmosidic triterpenoid saponin,BTS-1(3-O-β-D-galactopyranosyl-(1-2)-[β-D-xylopyranosyl-(1-3)]-β-D-glucuronopyranosyl gypsogenin 28-O-α-L-arabinopyranosyl-(1-3)-βD-xylopyranosyl-(1-4)-α-L-rhamnopyranosyl-(1-2)-β-D-fucopyranoside),in rat plasma.The assay was successfully applied to a pharmacokinetic study in rats given a single oral dose of BTS-1(400 mg/kg).The results indicated that the compound was rapidly absorbed(Tmax=1.2870.29 h,Cmax=37.475.6 mg/mL)and slowly eliminated(t1/2=13.276.6 h).In addition,secondary glycosides and aglycones of BTS-1 were detected and identified.Since these metabolites are known to be activeα-glucosidase inhibitors,they probably play an important role in mediating the pharmacological effects of the saponin.
AIM: To investigate the chemical constituents from the whole plants of Phlegmariurus fargesii. METHOD: Compounds were isolated by repeated silica gel column chromatography. Their structures were elucidated by spectroscopic methods and chemical correlation. The acetylcholinesterase(AChE) inhibitory activity of the isolated compounds was evaluated. RESULTS: A new Lycopodium alkaloid, lycopodine N-oxide(1), along with lycopodine(2), 8,15-dehydrolycopodine(3), 6α-hydroxylycopodine(4), deacetyllycoclavine(5), N-methylhuperzine B(6), lycodine(7), and phlegmarine(8), was isolated. CONCLUSION: Compound 1 is a new Lycopodium alkaloid, and compound 3 was obtained from nature for the first time. Other alkaloids are isolated from this plant for the first time.
Two new β-carboline-type alkaloids, dichotomine K （1） and dichotomine L （2）, were isolated from the roots of Chinese medicinal plant Stellaria dichotoma L. vat. lanceolata Bge. Structures of 1 and 2 were determined on the basis of chemical and spectroscopic means.
