"Fruiting Liquid" of Mushroom-Forming Fungi, A Novel Source of Bioactive Compounds - Fruiting-Body Inducer and HIF and Axl Inhibitors.

In general, mushroom-forming fungi secrete liquid on the surface of mycelia just before fruiting-body formation. However, no researchers in mushroom science have paid attention to the liquid until now. We formulated a hypothesis that the liquid plays an important role(s) in the formation of the fruiting body and produces various bioactive compounds and named it the "fruiting liquid (FL)". Four novel compounds ( 1 - 4 ) were isolated from FL of Hypholoma lateritium and Hericium erinaceus . The structures of 1 - 4 except for their stereochemistry were determined by interpretation of MS and NMR data. The absolute configurations of compounds 1 - 4 were determined by quantum chemical calculation of the ECD spectrum, by single-crystal X-ray diffraction analyses, or by chemical syntheses. Compounds 1 , 3 , and 4 induced fruiting body formation of Flammulina velutipes . Compound 4 inhibited the activity of hypoxia-inducible factor, and compounds 2 - 4 suppressed receptor tyrosine kinase (Axl) expression.