BIOSYNTHETIC STUDIES ON GLIOTOXIN USING STABLE ISOTOPES AND MASS SPECTRAL METHODS

The biosynthesis of gliotoxin has been studied using 15N- and 13Clabeled compounds and the organism Trichoderma uiride grown under aerobic conditions. Mass spectrometry was employed for determining the extent and the location of isotope labeling. The desthio derivative II, obtained by passing I through a column of alumina, was found suitable for spectral measurements. With milligram size samples of I or II and an analytical type of mass spectrometer, the isotope enrichment level could be determined rapidly. From a study of the fragmentation pattern of labeled and unlabeled II it was concluded that phenylalanine can be incorporated into I by at least two pathways: (a) intact and (b) via a nitrogen-free intermediate that undergoes reamination. Glycine can serve as the source of both nitrogen atoms in I. © 1968, American Chemical Society. All rights reserved.