Two brominatedtyrosine metabolites, fistularin 3 [1] and a new compound

11-ketofistularin 3 [2} have been isolated from a marine sponge, Aplystna archeri. Their structures were determined on the basis of spectral data. Both compounds inhibited the growth of feline leukemia virus.

Bromotyrosine-derived metabolites are distinct markers for the marine sponges belonging to the order Verongida (1). Examples of these brominated metabolites are fistularins 1—3 (2), 11, 19-dideoxyfistularin 3 (3), aerothionins (4—6), psammaplysin A (7, 8), bastadin 1 (9), anamonian A (10), ceratinins A and B (11), aplysamines 1 and 2 (12), and a series oi Aplystna thiona compounds (13). We now report another addition to the bromotyrosine familyof compounds. The MeOH/toluene extract of Aply-sina archeri (Higgin) of the family Aply-sinidae showed antiviral activity against feline leukemia virus. Bioassay-guided Si gel chromatography of EtOAc-soluble material from an MeOH/toluene extract followed by reversed-phase hplc furnished the antiviral constituents fistularin 3 II] and 11-ketofistularin 3 12]. Fistularin 3