A new pterocarpan, (-)-maackiain sulfate, from the roots of Sophora subprostrata

A new pterocarpan, (-)-maackiain 3-sulfate (1) was isolated from the methanol extract of roots of Sophora subprostarata together with (-)-maackiain (2), trifolirhizin (3), lupeol (4), ononin (5), 7,4'-dihydroxyflavone (6), and (+)-syringaresinol (7). The structure of 1 was determined by analyses of 2D NMR and HRFABMS. Compounds 5-7 were isolated from this plant for the first time.