Biotransformation of 20(S)-protopanaxatriol by Aspergillus niger and the cytotoxicity of the resulting metabolites

Abstract The microbial transformation of 20( S )-protopanaxatriol by cell suspension cultures of Aspergillus niger AS 3.1858 yielded metabolites 1 – 13 . The chemical structures of these transformed products were elucidated based on various spectroscopic analyses, including 1D and 2D NMR and HRESIMS. Metabolites 3 , 11 , and 13 are new compounds. Furthermore, metabolite 3 exhibited relative better activity profile toward the tested seven cancer cell lines (Du-145, Hela, K562, K562/ADR, SH-SY5Y, HepG2, and MCF-7) than substrate and preliminary structure-activity relationships were concluded.