An HIV RNase H inhibitory 1,3,4,5-tetragalloylapiitol from the African plant Hylodendron gabunensis.

A new compound, 1,3,4,5-tetragalloylapiitol ( 1), was isolated from the aqueous extract of the plant Hylodendron gabunensis and was found to be a potent inhibitor of RNase H enzymatic activity. The structure of 1 was elucidated by NMR analyses to be an apiitol ( 2) sugar moiety substituted with four gallic acid residues. Optical rotation measurements of the free sugar following basic hydrolysis indicated that the 3 S absolute configuration was the same as that of d-apiitol. Compound 1 inhibited HIV-1, HIV-2, and human RNase H with IC 50 values of 0.24, 0.13, and 1.5 microM, respectively, but it did not show inhibition of E. coli RNase H at 10 microM.