Isoflavonoid glycosides from the flowers of Pueraria lobata.

Pueraria lobata flower is a medicinal herb for treating intoxication, hepatic, and gastrointestinal tract lesions induced by alcohol. This study aims to investigate the isoflavonoid glycosides in P. lobata flowers. Two new isoflavone compounds were isolated from the extract of P. lobata flowers. Their structures were determined to be 5,6,7,4'-tetrahydroxyisoflavone-6,7-di-O-ß-D-glucopyranoside and 5,6,7-trihydroxy-4'-methoxyisoflavone-6,7-di-O-ß-D-glucopyranoside on the basis of spectroscopic means including HR-ESI-MS, UV, IR, ¹H, and ¹³C NMR.