Two New Derivatives of 2, 5-Dihydroxyphenyl Acetic Acid from the Kernel of Entada phaseoloides

Two new aromatic compounds, butyl 2,5-dihydroxyphenyl acetate (1) and butyl 2-O-beta-D-glucopyranosyloxy-5-dihydroxyphenyl acetate (2), together with three known ones, methyl 2,5-dihydroxyphenyl acetate (3), ethyl 2,5-dihydroxyphenyl acetate (4) and 2-O-beta-D-glucopyranosyloxy-5-hydroxyphenyl acetic 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 EC50 values of 9.80 mu M, 11.70 mu M and 9.93 mu M, respectively.