Antifungalmycin, an antifungal macrolide from Streptomyces padanus 702

Two polyene macrolide antibiotics: antifungalmycin (1) and fungichromin (2) were isolated from the culture mycelia of Streptomyces padanus 702 via bioactivity-guided fractionation using various chromatographic procedures. Their structures were elucidated on the basis of spectral analysis, and 1 is a new polyene macrolide. Compounds 1 and 2 showed significant inhibition against Gibberella zeae with EC50 values of 26.71 and 2.21 μg/mL, Fusicoccum sp. (plantain head blight) with EC50 values of 23.4 and 3.17 μg/mL, Mucor ssp. 8894 with EC50 values of 28.80 and 2.11 μg/mL, Ustilaginoidea virens with EC50 values of 26.72 and 0.21 μg/mL, respectively. This shows that the microbial secondary metabolites 1 and 2 have the potential to be developed as agricultural fungicides for use against G. zeae, Fusicoccum sp., Mucor ssp. 8894, and U. virens.