G1549, a new cyclic hydroxamic acid antibiotic, isolated from culture broth of Pseudomonas alcaligenes.

Antibiotic G1549, isolated from culture broth of Pseudomonas alcaligenes, is a new cyclic hydroxamic acid with a 1-hydroxy-2(1H)-pyridinone structure that complexes with metals. The structure of G1549 is suggested to be 1-hydroxy-5-methoxy-6-methyl-2(1H)-pyridinone. In vitro, G1549 and its copper and ferric complexes show moderate activity against Gram-positive bacteria, fungi and Trichomonas vaginalis. Topical application of G1549 and its copper and ferric complexes protect guinea pigs against cutaneous infection with Microsporum canis. The compounds, however, have some systemic toxicity in mice.