Bioactive Constituents of the edible wild mushrooms Gomphus clavatus and Lactarius salmonicolor

Mushrooms are recognized as an excellent nutritious food as well as an important source of biologically active compounds of medicinal value. In a continuation of our research for new bioactive secondary metabolites we have focused on the investigation of two widely consumed mushrooms widespread in North America, Europe and Asia. The wild mushrooms Gomphus clavatus and Lactarius salmonicolor were collected, lyophilized and extracted with DCM, MeOH and EtOH/H₂O sequentially. The screening for the antioxidant activity of the crude extracts, performed by a modification of DPPH method, revealed that the MeOH extracts were most active. Subsequently the fractionation and investigation of Gomphus clavatus MeOH extract lead to the isolation of: ergosterol, 5,8-hyperoxide of ergosterol, serevisterol, 3,5,6-trihydroxyergostan-7,9(11)22-triene, 3,5,6-trihydroxyergostan-7,22-diene, 3β,5α,9α-trihydroxy-(22E)-ergostan-7,22dien-6-one, nicotinic acid and indole-3-carboxylic acid. The investigation of Lactarius salmonicolor MeOH extract lead to the isolation of serevisterol, 3β,5α,9α-trihydroxy-(22E)-ergostan-7,22dien-6-one, nicotinic acid, p-hydroxybenzoic acid and a new natural azulene type product. The ergosterol derinatives were evaluated for their antioxidant activity and their estrogenic activity in MCF-7 (Breast cancer) and PC-3 (Prostate cancer) cell lines. Concerning estrogenic activity, the samples derived from saponification of DCM extract of Gomphus clavatus, rich in ergosterol derinatives and the pure compound of the peroxide of ergosterol, were the most active samples with IC₅₀ 15.1 and 15.3µg/ml in MCF-7 and 13.6 and 13.1µg/ml in PC-3 cell lines, respectively. Overall the isolated compounds had interesting activities and further research is needed in order to reveal the crucial role that mushrooms could play in human health when collected from the wild and consumed.