Two New 5,6,7-Trihydroxy-2-(2-phenylethyl)-5,6,7,8-tetrahydro-4H-chromones from Agarwood of Aquilaria walla from Sri Lanka

Abstract:

To investigate the chemical constituents from agarwood of Aquilaria walla from Sri Lanka, two new 2-(2-phenylethyl)chromone compounds were isolated from the ethanol extract by silica gel column chroma- tography, Sephadex LH-20 gel column chromatography and semi preparative high performance liquid chromate- graphy (HPLC). Based on spectral data, their structures were identified as (5R,6S,7S)-5,6,7-trihydroxy-5,6,7,8- tetrahydro-2-(2-phenylethyl)chromone (1) and (5R,6S,7S)-5,6,7-trihydroxy-5,6,7,8-tetrahydro-2-[2-(4-methoxy- phenyl)ethyl]chromone (2). Compounds 1 and 2 did not show inhibitory on the NO production induced by lipopolysaccharide (LPS) in mouse mononuclear macrophages RAW264.7, and cytotoxic activity against five common human cancer cell lines by MTT method. There was weak inhibitory effect of compound 2 on tyrosinase, with an inhibitory rate of (21.67±1.67)% at a concentration of 200 μg/mL.

Key words:Aquilaria walla;5,6,7-Trihydroxy-5,6,7,8-tetrahydro-2-(2-phenylethyl)chromone;Tyrosinase inhibition;New compound