Neurite Outgrowth-Inducing Drimane-Type Sesquiterpenoids Isolated from Cultures of the Polypore Abundisporus violaceus MUCL 56355

ABSTRACT: Abundisporin A (1), together with seven previously undescribed drimane sesquiterpenes named abundisporins B−H

(2−8), were isolated from a polypore, Abundisporus violaceus MUCL 56355 (Polyporaceae), collected in Kenya. Chemical structures

of the isolated compounds were elucidated based on exhaustive 1D and 2D NMR spectroscopic measurements and supported by

HRESIMS data. The absolute configurations of the isolated compounds were determined by using Mosher's method for 1−4 and

TDDFT-ECD calculations for 4 and 5−8. None of the isolated compounds exhibited significant activities in either antimicrobial or

cytotoxicity assays. Notably, all of the tested compounds demonstrated neurotrophic effects, with 1 and 6 significantly increasing

outgrowth of neurites when treated with 5 ng/mL NGF.