γ-Glutamyl-β-phenylethylamine, a novel and inhibitory compound from , an edible Nigerian mushroom.

species are known edible mushrooms in Nigeria, believed to have exceptional culinary and nutraceutical properties. Methanol extract from fruiting bodies of was evaluated for antidiabetic activity using α-amylase and α-glucosidase assays. The isolation and structural elucidation of metabolites from the . extract afforded five compounds including a new natural product γ-glutamyl-β-phenylethylamine and four known phenyl derivatives: tryptophan , 4-hydroxyphenylacetic acid , 4-hydroxyphenylpropionic acid , and phenyllactic acid . Structures were elucidated from analyses of spectroscopic data (1D and 2D NMR, HRESIMS) and all isolated compounds were tested for α-amylase and α-glycosidase inhibitory activity. The assay established crude extract to possess and inhibition with IC of 78.05µg/mL and 86.10µg/mL, respectively. The isolated compounds compared favourably with the standard drug, acarbose with IC ranging from 6.18-15.08µg/mL and 18.28-44.63µg/mL for α-amylase and glucosidase, respectively.