Phenolic compounds from the aqueous extract of Acacia catechu.

Two new phenolic compounds, 5-hydroxy-2-[2-(4-hydroxyphenyl) acetyl]-3-methoxylbenzoic acid (1) and (2S,3S)-3,7,8,3',4'-pentahydroxyflavane (2), were obtained from the aqueous extract of Acacia catechu, along with four known compounds identified as rhamnetin (3), 4-hydroxyphenyl ethanol (4), 3,3',5,5',7-pentahydroxyflavane (5), and fisetinidol (6). Their structures were determined on the basis of spectroscopic analysis. Free radical-scavenging activities of the new compounds were evaluated.