A New Alkaloid from Marine-Derived Actinomycete Actinoalloteichus cyanogriseus G631

A new alkaloid, isocyanogramide (1) together with six known compounds, including cyanogramide (2), marinacarboline F (3), marinacarboline H (4), caerulomycinamide (5), cerulomyconitrile (6), and 5MODIFIER LETTER PRIME-deoxyuridine (7) were isolated from the agar culture of the marine-derived actinomycete Actinoalloteichus cyanogriseus G631. Compounds 1-7 were evaluated for antimicrobial activity against Gram (+) bacteria, Enterococcus faecalis, Staphylococcus aureus, and Bacillus cereus, Gram-(-) bacteria, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, and the yeast, Candida albicans. All compounds significantly exhibited antibacterial effects on three tested Gram-(+) bacteria and the yeast C. albicans with the MIC values ranging from 64 to 256 mu g/mL. Compounds 4, 5, and 7 significantly inhibited B. cereus bacteria with MIC values of 16, 128, and 128 mu g/mL, respectively.