Chemical investigation of the glycosidic constituents of Oospora virescens (Link) Wallr. resulted in the isolation of several glycosides. We have shown recently [l] that two of them, named virescenoside A (I) and B (11) are p-D-altropyranosides of virescenol A and B; these diterpenic aglycones have been found to have the structure of isopimaradien-2cu,3p-l9-triol (IV) and isopimaradien-3,9,19&01 (V), respectively [2].I n this paper we describe the isolation and structure of virescenoside C, a new metabolite of