Inhibitors of prostaglandin biosynthesis from dalbergia odorifera

From the heartwood of Dalbergia odorifera T. Chen, a Chinese medicinal drug (Japanese name “Koshinko”) used for the stagnation of disordered blood, five new phenolic compounds, isomucronustyrene (2) and hydroxyobtustyrene (3) (cinnamylphenol), (±)-isoduartin (6) (isoflavan), odoriflavene (7) (isoflav-3-ene) and (-)-odoricarpan (15) (pterocarpan) were isolated and their structures were elucidated on the basis of chemical and spectroscopic methods. Of the fifteen compounds isolated, the cinnamylphenols, isoflavans, isoflav-3-ene and a benzoic acid derivative inhibited prostaglandin biosynthesis more than the oterocarpan and isoflavone compounds.