Two new derivatives of 2, 5-dihydroxyphenylacetic acid from the kernel of Entada phaseoloides.

Two new aromatic compounds, butyl 2,5-dihydroxyphenylacetate (1) and butyl 2-O-β-D-glucopyranosyloxy-5-dihydroxyphenylacetate (2), together with three known ones, methyl 2,5-dihydroxyphenylacetate (3), ethyl 2,5-dihydroxyphenylacetate (4) and 2-O-β-D-glucopyranosyloxy-5-hydroxyphenylacetic acid (5), were isolated from the EtOH extract of the kernel of Entada phaseoloides. The structures of the new compounds were elucidated by MS and NMR experiments. Compounds 1, 3 and 4 displayed potent inhibitory activities against HIV-1 replication, with EC(50) values of 9.80 μM, 11.70 μM and 9.93 μM, respectively.