Identification of bolegrevilol B and C as novel antioxidant compounds in Suillus grevillei mushroom.

Suillus grevillei is a popular species of mushroom available worldwide. In this study, we isolated compounds, bolegrevilol B and bolegrevilol C, from the mushroom and observed their potent lipid peroxidation-inhibiting activity. The structures of bolegrevilol B and bolegrevilol C were elucidated as 3-geranylgeranyl-1,2,4-trihydroxybenzene and 3-geranylgeranyl-1,2-dihydroxy-4-methoxybenzene, respectively, through high-resolution electrospray ionization mass spectrometry (-) and 1D and 2D nuclear magnetic resonance analyses. Bolegrevilol B and C inhibited lipid peroxidation and exhibited IC50 values of 2.0 ± 0.29 µm and 1.0 ± 0.13 µm, respectively. Furthermore, bolegrevilol B and C demonstrated potent neuroprotective activities in neuronal hybridoma N18-RE-105 cells against L-glutamate toxicity (EC50 of 1.8 ± 1.7 n m and 7.2 ± 6.9 n m, respectively). Bolegrevilol B was found in nature for the first time, and, to the best of our knowledge, this is the first study to report the antioxidant activities of bolegrevilol B and C.