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 3S absolute configuration was the same as that of d-apiitol. Compound 1 inhibited HIV-1, HIV-2, and human RNase H with IC50 values of 0.24, 0.13, and 1.5 µM, respectively, but it did not show inhibition of E. coli RNase H at 10 µM.