Study on coumarins of Trigonostemon lutescens / 中草药

ABSTRACT

Objective To study the chemical constituents in 95% ethanol aqueous extract of Trigonostemon lutescens. Methods The open silica gel, MCI, Sephadex LH-20 column chromatography, and the semi-preparative HPLC were used to isolate and purify the chemical constituents from the EtOAc fraction of T. lutescens. The structures of the isolates were elucidated by their physiochemical properties, NMR, and MS spectroscopic data, as well as comparison with literature data. Results Eleven compounds were isolated from the EtOAc fraction of the 95% aqueous EtOH extract of T. lutescens, and their structures were identified as seven coumarins, auraptenol (1), meranzin hydrate (2), xanthotoxin (3), bergapten (4), isoimpinellin (5), alloisoimperatorin (6), and isodemethylfuropinarine (7); Two phenylalanine glycosides, 3,4-dihydroxy allylbenzene-4-O-β-D-glucopyranoside (8) and 1-O-β-D-glucopyranosyl-4- allylbenzene (9); One phenylethanol, 1-(2-ethylphenyl)-1,2-ethanediol (10); One alkaloid, 8-hydroxy-3-methoxy-5H-pyrido [2,1-c] pyrazin-5-one (11). Conclusion All these compounds are isolated from the genus Trigonostemon for the first time.