Cytotoxic amides from the octocoral Telesto riisei.

Two new acyl derivatives of beta-phenylethylamine, N-(2-phenylethyl)-9- oxohexadecacarboxamide (1) and N-(2-phenylethyl)-9-hydroxyhexadecacarboxamide (2), and two new tetrahydroxysterols, cholestane-3 beta, 5 alpha,6 beta-26-tetrol 27-acetate (3) and cholestane-3 beta, 5 alpha, 6 beta-26-tetrol (4), have been isolated from the coelenterate Telesto riisei collected in Chuuk, Federated States of Micronesia. Structures were determined from spectroscopic data. All new compounds were mildly toxic to murine leukemia cells (P-388) in culture.