Dolichandroside A,a new α‐glucosidase inhibitor and DPPH free‐radical Scavenger from Dolichandrone falcata seem

A new phenylpropanoid glycoside, dolichandroside‐A, together with seven known compounds α‐lapachone, lapachol, aloesaponarin II, 8‐hydroxydehydroiso‐α‐lapachone, β‐sitosterol, 3,8‐dihydroxydehydroiso‐α‐lapachone and verbascoside were isolated from the active ethyl acetate soluble extract of heartwood of Dolichandrone falcata. All except for dolichandroside‐A are known compounds, but have been isolated for the first time from this plant. The structure of all these compounds was determined on the basis of 1D‐ and 2D‐NMR spectral data. All the isolates were tested for α‐glucosidase inhibitory and DPPH radical scavenging activity. This is the first report identifying DPPH scavenging activity and α‐glucosidase inhibitory activity in D. falcata. Furthermore, along with a new compound, dolichandroside‐A, this study also assigns for the first time α‐glucosidase inhibitory activity to verbascoside and aloe saponarin‐II. Copyright © 2008 John Wiley & Sons, Ltd.