Chaetoglobosins, cytotoxic 10-(indol-3-yl)-(13)cytochalasans from Chaetomium spp. IV. 13C-Nuclear magnetic resonance spectra and their application to a biosynthetic study.

Assignments of the 13C-nuclear magnetic resonance signals of eight naturally occurring chaetoglobosins were established. Incorporations of [1-13C]-, [2-13C]-, and [1, 2-13C2]-acetate, [13C-methyl]-L-methionine, and [1-13C]-and [2-13C]-DL-tryptophan into chaetoglobosins A and C by Chaetomium globosum demonstrated that the molecules were formed from nine units of acetate/malonate, three C1 units, and one unit of tryptophan.