Zhang_2025_Phytochemistry__114489

Eight previously undescribed epipolythiodioxopiperazines (ETPs), asperstrins A-H (1-8), and three known analogues, dethiosecoemestrin (9), secoemestrin C (10), and secoemestrin D (11), were isolated from the endophytic fungus Aspergillus nidulans. Their structures and configurations were elucidated based on HRESIMS, one-dimensional and two-dimensional nuclear magnetic resonance spectroscopic data, electronic circular dichroism calculations, and X-ray crystallography. Asperstrins A-C (1-3) represent the first examples of O-methyl or O-ethyl derivatives of emestrin-type ETPs, respectively. Asperstrin C (3) showed moderate cytotoxic activities with IC(50) values ranging from 3.00 to 4.60 microM; asperstrins F (6) and G (7) displayed potent butyrylcholinesterase inhibitory activities with IC(50) values of 9.49 +/- 0.51 and 2.03 +/- 0.55 microM, respectively.