Metabolites of the higher fungi. Part 24. Cytochalasin N, O, P, Q, and R. New cytochalasins from the fungus Hypoxylon terricola Mill

Punctaporonin B, cytochalasin C and D, and five new cytochalasins have been isolated from the culture medium and mycelium of the fungus Hypoxylon terricola. Cytochalasin C is the major metabolite. Cytochalasin N is the 5,6-epoxide of cytochalasin C, and cytochalasins O and P are two epimeric 6-hydroxy analogues. Cytochalasin Q is a 6,7-epoxide and R is a 6,7,13,14-diepoxide. The epoxides formed by cytochalasin C and D are described and the acid- and BF3-induced rearrangement products of cytochalasin N are identified.