Bisabolanoic acid A, a new polychiral sesquiterpene with AChE inhibitory activity from a mangrove-derived fungus <i>Colletotrichum</i> sp.

Abstract

A new polychiral bisabolane sesquiterpene, bisabolanoic acid A (<b>1</b>), was isolated from the mangrove-derived fungus <i>Colletotrichum</i> sp. SCSIO KcB3-2. Its planar structure was identified on the basis of spectroscopic data analysis (HRESIMS, 1D, and 2D NMR), and the absolute configurations of three chiral carbons were determined by experimental and calculated electronic circular dichroism (ECD) and optical rotatory dispersion (ORD), together with Mo₂(OAc)₄-induced ECD methods. Bisabolanoic acid A (<b>1</b>) showed moderate inhibitory activity against acetylcholinesterase (AChE) with IC₅₀ value of 2.2 μM, and the <i>in silico</i> molecular docking was also performed.