A new antifungal macrolide from Streptomyces sp. KIB-H869 and structure revision of halichomycin

A new hygrolidin-type macrolide (1), together with one known derivative, oxohygrolidin (2), were isolated from the culture of Streptomyces sp. KIB-H869. The structure of the new compound was elucidated by means of extensive spectroscopic analysis. Moreover, by the biogenesis ratiocination and NMR data comparison, halichomycin and 2 were confirmed to have the same structure, which corrects the structural misrepresentation of halichomycin. The antifungal activities of the two compounds were evaluated.