BARTANOL AND BARTALLOL, NOVEL MACRODIOLIDES FROM CYTOSPORA SP ATCC-20502

Two new macrodiolides, bartanol 10 and bartallol 11 have been isolated from a Cytospora sp. and their structures established by a detailed s tudy of their high field H-1 and C-13 NMR spectra. Unlike the other 14 -membered ring macrodiolides isolated from this source, bartanol and b artallol have a novel rearranged 13-membered macrocyclic ring. The con formations of the macrocyclic ring have been deduced from the analyses of difference NOE spectra and H-1-H-1 coupling constants.