Clathsterol, a novel anti-HIV-1 RT sulfated sterol from the sponge Clathria species.

As part of a search for novel inhibitors of humandeficiency virus type 1 (HIV-1) reverse transcriptase (RT), the MeOH-EtOAc extract of a Red Sea sponge, Clathria sp., was shown to be active. Bioassay-guided fractionation of the extract yielded a novel sterol sulfate, clathsterol (1), which is responsible for the activity and is active at a concentration of 10 microM. The structure of 1 was established mainly by interpretation of spectral data and a chemical transformation.