HPLC-DAD characterization of phenolic profile and in vitro antioxidant, anticholinesterase, and antidiabetic activities of five mushroom species from Turkey.

In this study, Daedalea quercina (L.) Pers., Hydnum repandum L., Inonotus radiatus (Sowerby) P. Karst., Omphalotus olearius (DC.) Singer, and Schizophyllum commune Fr. hexane and methanol extracts were subjected to the spectrophotometric assays for antioxidant and enzyme inhibitory activities, which are linked with human diseases that are very prevalent in recent years. Additionally, phenolic compounds of the mushrooms were quantified by HPLC-DAD. The best antioxidant activity was found in H. repandum methanol extract (IC50: 12.04 ± 0.24 µg/mL) in the β-carotene-linoleic assay; I. radiatus methanol extract in DPPH• (81.22 ± 0.50%), ABTS•+ (IC50: 73.47 ± 0.18 µg/mL), and CUPRAC (A0.50: 88.21 ± 0.02 µg/mL) assays; S. commune hexane extract (53.36 ± 0.89%) in the metal chelating assay. O. olearius hexane extract was found as the best inhibitor against AChE (71.58 ± 0.28%) and BChE (67.30 ± 0.15%). When I. radiatus methanol (95.88 ± 0.74%) and H. repandum hexane (95.75 ± 0.16%) extracts showed close α-amylase inhibitory activity to acarbose (96.68 ± 0.08%), D. quercina methanol extract (70.79 ± 0.34%) had higher α-glucosidase inhibitory activity than acarbose (67.01 ± 2.28%). Among 16 phenolic compounds analyzed, gallic acid (0.02 ± 0.01-0.23 ± 0.01 µg/g) was detected in all studied mushrooms. This study provides that investigated mushrooms can be used for further research, which can lead to the development of new natural remedies to alleviate complications related to oxidative stress, diabetes, and neurological diseases.