Isoflavone Tetraglycosides from Sophora japonica Leaves

Two new isoflavone tetraglycosides (1 and 2) and six known compounds were isolated from the leaves of Sophora japonica. The new glycosides are genistein 7-O-β-d-glucopyranoside-4′-O-(6′′′-O-α-l-rhamnopyranosyl)-β-sophoroside (1) and genistein 7-O-α-l-rhamnopyranoside-4′-O-(6′′′-O-α-l-rhamnopyranosyl)-β-sophoroside (2). The structures of compounds 1 and 2 were established primarily by NMR experiments and chemical methods, and they are the first reported naturally occurring isoflavone glycosides with four attached sugar residues.