Sclerodin and related compounds from a plant disease causing fungus. Scleroderris yellow

Abstract

The metabolites of several strains of a fungus that gives rise to the disease of conifers known as Sirococcus shoot blight have been studied. The metabolites are similar to those isolated from Gremmeniellaabietina, the causative agent of Scleroderris canker of pine. Sclerodin (1), scleroderolide (2), and Scleroderris blue (3) have been isolated, along with the known lactone 4, trypethelone (6), and a new purple compound named scleroquinone (12). Another new compound, related to Scleroderris blue (3) and Scleroderris green (7); which we have named Scleroderris yellow, is shown to possess structure 8. The sclerodin (1) isolated in these studies is not optically pure, in some cases being nearly racemic. It is noted that the optical purity may be a function of the culture medium employed. Scleroderolide (2) strongly inhibits the germination of lettuce seeds. In addition to the metabolites noted, squalene, methyl oleate, stearic acid, ergosta-4,6,8(14),22-tetraene-3-one, and ergosterol endoperoxide were also isolated from the cultures. Keywords: Sirococcus, phenalenones, Scleroderris yellow, scleroquinone, sclerodin.