Abstract
Hericium erinaceus is an edible and medicinal mushroom. Previously, we found hericenones C-H from the fruiting bodies and erinacines A-I from the mycelia of the fungus. These compounds stimulated nerve growth factor (NGF) synthesis both in vitro and in vivo; some have been suggested to be effective in the prevention and treatment of dementia. Recently, the total synthesis of hericenones C-H and their derivatives (1-4) was reported by one of the authors. We considered that the chemical synthetic route would also be reasonable as a biosynthetic pathway of the compounds. Based on the hypothesis, we investigated the endogenous existence of synthetic intermediates and products of the chemical synthesis in the fruiting bodies. The n-hexane-soluble part of the fruiting bodies of H. erinaceus was fractionated, and all the fractions were subjected to a product ion scan and multiple reaction monitoring (MRM) analysis by LC-MS/MS and compared to the authentic synthesized compounds. The analysis indicated the endogenous existence of 1-4 and the dehydrated form of 2 or 3. The dehydrated form was elucidated to be (Z)-5 by chemical synthesis, and a plausible biosynthetic pathway was proposed.