A new 1,2-ethanedione benzofurane derivative from Tephrosia purpurea

A new 1,2-ethanedione benzofurane derivative, purpdione (1), was isolated from Tephrosia purpurea, together with seven known flavonoids, purpurenone (2), pongamol (3), ovalitenin A (4), karanjin (5), lanceolatin B (6), tachrosin (7) and villosinol (8). The new structure was elucidated based on the analysis of its spectroscopic data. The structures of the known compounds were identified by comparing their spectroscopic data with those reported in the literature. The isolates exhibited marginal ability to inhibit the settlement of barnacle (Balanus reticulatus).