Ergosta-4,6,8,22-tetraen-3-one from the edible fungus, Pleurotus ostreatus (oyster fungus)

From extracts of the dried oyster fungus, Pleurotus ostreatus, three steroidal fractions were obtained. The major fraction was proved to be ergosterol and the second a mixture of two fatty acid esters of ergosterol, which could not be fully resolved. The minor fraction contained ergosta-4,6,8,22-tetraen-3-one, which has not been recorded previously. © 1997 Elsevier Science Ltd. All rights reserved