CRYTOPORIC ACIDS A-G, DRIMANE-TYPE SESQUITERPENOID ETHERS OF ISOCITRIC ACID FROM THE FUNGUS CRYPTOPORUS VOLVATUS

Article abstract of DOI:10.1016/0031-9422(92)90042-O

Seven novel bitter drimane-type sesquiterpenoids with an isocitric acid group named cryptoporic acids (CA) A-G have been isolated from the fungus Cryptoporus volvatus and their absolute stereostructures established by a combination of chemical transformation, NMR spectral data and X-ray crystallographic analysis.Crytoporic acids strongly inhibited the release of superoxide anion radicals from guinea-pig peritoneal macrophage as well as rabbit polymorphonuclear leucocyte.CA-E showed anti-tumour promoting activity whilst CA-D slightly enhanced tumour promoting and protein kinase C activity.CAs also inhibited elongation of the second coleoptile and germination of rice in husk at 200 ppm. Key words: Cryptoporus volvatus; Polyporaceae; fungus; drimane-type sesquiterpenoid ethers; isocitric acid; superoxide anion radical release inhibitor; anti-tumour and tumour promoting activity; protein kinase C enhancement; plant growth inhibitory activity; bitter principles.