Novel aspartyl protease inhibitors, YF-0200R-A and B

Novel pepstatin A-sensitive Candida albicans aspartyl protease inhibitors, named YF-0200R-A and B, were isolated by column chromatography and preparative HPLC from the fermentation broth of Streptomyces sp. YF-0200R. The structures of YF-0200R-A and B were elucidated by spectroscopic analysis as alpha, beta and gamma, delta unsaturated fatty acids with two or three hydroxyl groups. YF-0200R-A and B inhibit aspartyl protease from Candida albicans with IC50 values of 6.5 x 10(-4) M and 6.2 x 10(-4) M, respectively.