Constituents of the rhizomes of Sansevieria cylindrica

A new sappanin-type 3-benzyl chroman-4-one (homoisoflavanone), (3S)-3-(4′-methoxybenzyl)-3,5-dihydroxy-7-methoxy-6-methyl chroman-4-one (1), together with known congeners (3S)-3-(4′-methoxybenzyl)-3,5-dihydroxy-7-methoxy chroman-4-one (2), (3S)-3-(4′-hydroxybenzyl)-3,5-dihydroxy-7-methoxy-6-methyl chroman-4-one (3), (3S)-3-(4′-hydroxybenzyl)-3,5-dihydroxy-7-methoxy chroman-4-one (4), 3-(3’,4’-methyledioxybenzyl)-7-hydroxy-8-methoxy chroman-4-one (5), and stigmasterol and ergosterol peroxide have been isolated from the rhizomes of Sansevieria cylindrica, collected in Myanmar. Moreover, the first isolation of the (-)-enantiomer of the dihydrochalcone trifasciatine C (7) from nature is described. The structures of the compounds have been established by extensive spectroscopic analysis. Compounds 4 and 7 showed no significant cytotoxicity against HeLa cells. Compounds 1-4 and 7 exhibited weak radical scavenging activity (DPPH). A new biosynthetic pathway has been proposed for the formation of homoisoflavanone 5 and dihydrochalcone 7.