Following the characterization of callipeltoside A (1), the first member of a novel class of marine glycoside macrolides, two more bioactive constituents, callipeltoside B (2) and C(3), were isolated from Callipelta sp. in very low amounts. The structures, assigned on the basis of spectral analysis, include the same 14-membered macrolide as in callipeltoside A (1) but differed in the saccharide moieties.