Pharesinosides A-G, acylated glycosidic acid methyl esters derivatized by NH2 silica gel on-column catalyzation from the crude resin glycosides of Pharbitis Semen

Application of NH2 silica gel column chromatography using CH2Cl2-MeOH was found to show a satisfactory resolution for separation of the crude resin glycosides of Pharbitis Semen (the seeds of Pharbitis nil), led to the isolation of seven new acylated glycosidic acid methyl esters, Pharesinosides A-G (1-7), along with four known ones (8-11). These compounds (1-11) were considered to be generated via methyl esterification of the carboxyl group in acylated glycosidic acids. Their structures including stereochemistry were elucidated on the basis of a combination of the spectroscopic and chemical methods. All isolates were evaluated for anti-tumor migration activities with human colon cancer cell line HCT-116, and compound 7 exhibited a potent migration inhibitory activity.

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