Synthesis of a Sulphur-containing Degradation Product from Gliotoxin

Abstract

GLIOTOXIN, a potent fungicide isolated from culture filtrates of Gliocladium fimbriatum, Trichoderma viride and other organisms¹, has been extensively examined by J. R. Johnson and his colleagues², who ascribe to it the provisional structure (I). The presence of the pyrazinoindole nucleus and of the disulphide grouping appear to be established with reasonable certainty. The points of attachment of the disulphide grouping to the pyrazinoindole nucleus, on the other hand, merit further confirmation. Treatment of gliotoxin with methanolic potassium hydroxide followed by acidification of the reaction mixture gives a sulphur-containing product, m.p. 188°, which appears to have the molecular formula C₁₁H₈ON₂S and for which the thiohydantoin structure (II) has been suggested³.