Polysubstituted Isoflavonoids from Spatholobus suberectus, Flemingia macrophylla, and Cudrania cochinchinensis

ABSTRACT: Four hitherto unknown polysubstituted isoflavonoids, including three isoflavans: 7,4′-dihydroxy-8,2′,3′-trimethoxyisoflavan (1), 7,2′,4′-trihydroxy-8,3′-dimethoxyisoflavan (2), and 7,2′,4′-trihydroxy-5-methoxyisoflavan (3), and one prenylated isoflavone cudraisoflavone M (4) were isolated from the ethanol extracts of Spatholobus suberectus (for 1 and 2), Flemingia macrophylla (for 3), and Cudrania cochinchinensis (for 4), respectively. Their structures were established on the basis of extensive spectroscopic analysis. Compounds 1 and 4 exhibited weak cytotoxic activity against five human cancer cell lines (HL-60, A-549, SMMC-7721, MCF-7, and SW-480). GRAPHICAL ABSTRACT: [Image: see text] ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s13659-017-0121-2) contains supplementary material, which is available to authorized users.