Repenins A–D, four new antioxidative coumarinolignoids from Duranta repens Linn.

Phytochemical investigations on the CHCl3-soluble fraction of the whole plant of Duranta repens Linn. led to the isolation of four new coumarinolignoids, Repenins A–D (1–4), along with the known coumarinolignoids, cleomiscosin A (5) and durantin A (6). Their structures were determined by modern spectroscopic analysis including 1D and 2D NMR techniques and chemical studies. The compounds (1–6) showed potent antioxidative scavenging activity against DPPH radicals, with IC50 values in the range 0.420–0.625 mM. Repenin B (2) displayed the strongest scavenging potential with IC50 values of (0.420 mM).

Structures and important mass fragmentation pattern of coumarinolignoids (1–6).Figure optionsDownload as PowerPoint slide