Chemical and analytical screening of some edible mushrooms

Abstract Fractionation of extracts of the edible mushroom, Volvariella volvacea , led to the isolation of two heterocyclic carboxylic acids, namely pyridine-3-carboxylic acid [nicotinic acid, ( 5 )] and pyrazole-3(5)-carboxylic acid ( 6 ) and the four steroidal metabolites ergosterol ( 1 ), 5-dihydroergosterol ( 2 ), ergosterol peroxide ( 3 ), cerevisterol ( 4 ). Significantly, compound ( 6 ) was identified for the first time, to our knowledge, in the mushroom kingdom and is of taxonomic significance. Compounds ( 2–4 ) were isolated for the first time from the Volvariella genus. In view of the structural similarity of compound ( 6 ) to pyrazole-3-carboxylic acids, which act as agonists for nicotinic acid receptors, the levels of compounds ( 5 ) and ( 6 ) were estimated for the first time using HPTLC in V. volvacea and two other edible mushrooms, namely Agaricus bisporus and Calocybe indica . Significant levels of compound ( 5 ) were found in C. indica , and compound ( 6 ) was found in abundance in A. bisporus . Correlations are suggested between the occurrence of these compounds in mushrooms and consumption as well as beneficial health effects of this food.