Bioactivity of Morchella esculenta (L.) Pers. phenolic extracts: A comparative study between samples from Portugal and Serbia.

Mushrooms contain a huge diversity of biomolecules with bioactive properties [1-3] that should be explored. Morchella esculenta (L.) Pers. (morel) is one of the most highly prized edible mushrooms in the world. In the present work a comparative study on the antioxidant properties (scavenging activity, reducing power and inhibition of lipid peroxidation) and antimicrobial activity (antibacterial and demelanizing properties) of phenolic extracts of two samples from two countries, Portugal and Serbia, was performed. Furthermore, the extracts were chemically characterized regarding phenolic acids composition, using HPLC-DAD-MS. The sample from Portugal (SP) gave higher radical scavenging activity and reducing power, while sample from Serbia (SS) showed higher lipid peroxidation inhibition. Both samples showed antibacterial activity against five bacteria [Escherichia coli (ATCC 35210), Salmonella typhimurium (ATCC 13311), Enterobacter cloacae (human isolate) and Gram-positive bacteria: Listeria monocytogenes (NCTC 7973) and Staphylococcus aureus (ATCC 6538)], in some cases even better than standard antibiotics, and demelanizing activity against four micromycetes (Aspergillus fumigatus, Aspergillus flavus, Penicillium funiculosum and Penicillium ochrochloron), SS showing higher activities. Protocatechuic and p-hydroxybenzoic acids were found in both samples, but p-coumaric acid was only quantified in the SP. As far as we know, this is the first study reporting phenolic compounds and bioactivity of morel samples from Portugal and Serbia. Furthermore, a novel method for evaluation of demelanizing activity is presented. Further studies are needed in order to elucidate the mechanisms of action involved in morel bioactivity and contribution of the identified compounds.