Melanoxylonin A-G, neoflavonoids from the heartwood of Dalbergia melanoxylon and their cardioprotective effects.

Seven undescribed neoflavonoids, named melanoxylonins A-G, were isolated from the heartwood of Dalbergia melanoxylon, and all the non-toxic isolates were evaluated for their cardioprotective effect against ischemia/reoxygenation (I/R) injury in H9c2 cells. Of these, melanoxylonin A-D containing the 8-OH group showed better potent cardioprotective effects than the other four congeners. Molecular docking studies confirmed the capacity of melanoxylonin D to interact with the myeloperoxidase (MPO) protein. These results indicated that the potential cardioprotective effects of melanoxylonin D in H9c2 cells with I/R injury may be imparted through suppression of MPO. These results may provide a new medicinal usage of D. melanoxylon.