Neogrifolin derivatives possessing anti-oxidative activity from the mushroom Albatrellus ovinus

Three neogrifolin derivatives, 3-hydroxyneogrifolin, 1-formylneogrifolin and 1-formyl-3-hydroxyneogrifolin along with grifolin and neogrifolin were isolated from the Japanese mushroom Albatrellus ovinus belonging to Scutigeraceae. Their structures were established by a combination of two-dimensional NMR spectroscopic analyses and by chemical synthesis. 3-Hydroxyneogrifolin and 1-formyl-3-hydroxy-neogrifolin showed more potent antioxidative activity properties than either alpha-tocopherol or BHA.     

Synthesis of natural product-like polyprenylated phenols and quinones: Evaluation of their neuroprotective activities

Twenty-seven natural product-like polyprenylated phenols and quinones were synthesized and their neuroprotective activity was tested using human monoamine oxidase B (MAO-B) and SH-SY5Y cells. Eight compounds inhibited MAO-B (IC₅₀ values < 25 μM) and the inhibition mode and molecular docking of two (8c and 16c) were investigated. Compounds inhibiting MAO-B activity were additionally tested for their ability to protect SH-SY5Y cells from peroxide injury. Three derivatives (3c, 8c and 16c) exhibited both MAO-B inhibitory and neuroprotective activity. A structure activity-relationship study showed that a phenolic hydroxyl group and a longer side chain are important for both activities.