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Two new diterpenes possessing a 9-methyladeninium substituent, agelasines H (5) and I (6), along with five related known ones, 1-4 and 7, were isolated from a sponge, Agelas sp. The structures of the new compounds were determined from spectral data. Compounds 2-4, 6, and 7 exhibited varying degrees of antimicrobial activity.

Four new imidazole alkaloids, 2-5, along with the known isonaamidine B (1) were isolated from a Pacific sponge, Leucetta cf. chagosensis, collected from Yap, Federated States of Micronesia. Among these, 4 and 5 are zinc complexes derived from isonaamidine B and isonaamidine D. The structures of the new compounds were elucidated from spectral data. Isonaamidine D (3) showed weakly antifungal activity against Aspergillus niger with MIC = 100 micrograms/mL.

Two new nitrotyramine derivatives, 1 and 2, along with five known aromatic compounds, were isolated from the culture broth of a facultatively anaerobic, halophilic bacterium isolated from a sediment from the Great Salt Plains, Alfalfa County, Oklahoma. The structures of the new compounds were determined from spectral data and were confirmed by synthesis from tyramine hydrochloride. Compound 1 showed cytotoxicity against the murine leukemia P-388 cell line (IC50 3 micrograms/ml).