Cell wall active antifungal compounds produced by the marine fungus Hypoxylon oceanicum LL-15G256. III. Biological properties of 15G256 gamma.

15G256 gamma is a cyclic lipopeptide antifungal agent discovered in a mechanism of action screen for cell wall acting antifungal agents. The compound shows moderate activity in both greenhouse tests against plant disease caused by pathogenic fungi and in in vitro tests against human fungal pathogens. Microscopic examination of treated fungi suggests that the compound acts by the inhibition of cell wall biosynthesis. However, in vitro inhibition of Neurospora crassa glucan and chitin synthase were only observed at high drug concentrations suggesting that 15G256 gamma may act on a novel cell wall target.