The sponge Batzella sp. from Jamaica contains four new alkaloids, batzelladines F-I (1-4), that induce the p56lck-CD4 dissociation. Batzelladines F-I were isolated using a bioassay-directed fractionation scheme and were identified by interpretation of spectroscopic data. Batzelladines F, G, and H + I were active in the p56lck-CD4 dissociation assay at micromolar concentrations.