Revised H-1 and C-13 NMR assignments of the polyene antibiotic filipin III

The major polyene antibiotic macrolide isolated from Streptomyces filipinensis, filipin III, was reinvestigated in DMSO solution using homonuclear and heteronuclear correlation spectroscopy. In addition to several corrections to precious H-1 NMR assignments, the nine exchangeable hydroxylic protons were structure-specifically assigned together with C-13 NMR lines using proton-detected HSQC spectroscopy. The magnitudes of the (3)J proton-proton couplings indicated a probable constrained geometry of the macrocyclic lactone. (C) 1997 by John Wiley & Sons, Ltd.