Immunosuppressive components from an Ascomycete, Diplogelasinospora grovesii

Two known fungal metabolites, macrophin and colletodiol, and a new stereoisomer of colletodiol named 10-epi-colletodiol, were isolated as immunosuppressive principles from an Ascomycete, Diplogelasinospora grovesii. The IC50 values of the major active component among them, macrophin, were calculated to be 0.4 and 0.3 microgram/ml against concanavalin A- and lipopolysaccharide-induced proliferations of mouse spleen lymphocytes, respectively. A new natural product, 4,8-dimethyl-1,5-dioxacyclooctane-2,6-dione, and a known fungal metabolite, isosclerone, which showed no immunosuppressive activity, were also isolated from this fungus.