[Isoflavone glycosides from the bark of Maackia amurensis]

To study the chemical constituents of the Maackia amurensis, the constituents were isolated by various chromatographies and the structures were elucidated on the basis of chemical and spectroscopic data (ESI-MS, 1D and 2D NMR). Thirteen isoflavone glycosides were isolated from the n-BuOH-soluble fraction of the 70% ethanol extract and identified as 7-hydroxy-4',6-dimethoxyisoflavone-7-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside (1), dalsympathetin (2), ononin (3), glycitin (4), genestin (5), saikoisoflavonoside A (6), afrormosin-7-O-beta-D-glucopyranoside (7), gehuain (8), kushenol O (9), 7-hydroxy-4',6-dimethoxyisoflavone-7-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside (10), tectoridin (11), biochanin A 7-O-beta-D-gentiobioside (12) and 7-hydroxy-4'-methoxyisoflavone-7-O-beta-D-apiofuranosy l-(1-->6)-beta-D-glucopyranoside (13). Compound 1 is a new isoflavone glycoside, named as maackiaisoflavonoside, compounds 2, 8, 9, 10, 12 and 13 were isolated from this genus for the first time.