Isoflavones and dihydrophenanthrene from Dalbergia tonkinensis.
The plants of the Dalbergia genus have been used for a long time in Vietnamese traditional medicine. In our continuing study on the chemical constituent and biological activities of medicinal plants, a phytochemical investigation of the methanol extract of Dalbergia tonkinensis led to the isolation of two isoflavones (1, 2) and a dihydrophenanthrene (3). Their structures were identified hy spectroscopic methods including ESl-MS, ID- and 2D-NMR in comparison with the literature. Compounds was found for the first time fi'om the Dalbergia species.