Pongamone A-E, five flavonoids from the stems of a mangrove plant, Pongamia pinnata

Chemical investigation of stems of the mangrove plant, Pongamia pinnata, resulted in isolation and characterization of five structurally unusual flavonoids pongamones A-E, along with 16 known flavonoid metabolites. Their structures were determined on the basis of spectroscopic analyses and by comparison of their spectroscopic data with those of related compounds reported in the literature. Pongamones A-E were assayed against DHBV RCs DNAP and HIV-1 RT in vitro. A possible biogenetic pathway of the isolated compounds is also proposed.