Rotenoid and isoflavone metabolites from an antioxidant seed extract of Dalbergia lanceolaria subsp. paniculata (roxb.) thoth.

A new rotenoid named 12-O-methylrotenolol along with five known rotenoid and isoflavone metabolites were isolated from the seeds of Dalbergia lanceolaria subsp. paniculata, collected from Egypt. The structures of these compounds were identified by physical and spectroscopic data measurements ([α]D, UV, 1D- and 2D-NMR and MS). The methanol extract of the seeds exhibited strong antioxidant activity with IC50 value 0.7 µg/µl against DPPH radical, in respect to quercetin as antioxidant reference (IC50 1.5 μM), while the tested compounds from this extract showed weak activities with IC50 values ranged from 19.6 to 33.0 µM.