Quadristerols A−G: Seven undescribed ergosterols from Aspergillus quadrilineata

• Published in: Phytochemistry (Oxford) 2023-09, Vol.213, p.113785-113785, Article 113785
• Main Authors: Wei, Mengsha, Li, Xiaoxin, Liao, Hong, Liu, Linlin, Li, Qin, Sun, Weiguang, Chen, Chunmei, Zhu, Hucheng, Zhang, Yonghui
• Format: Article
• Language: English
• Subjects: Aspergillus - chemistry; Aspergillus quadrilineata; Crystallography, X-Ray; Ergosterol - pharmacology; Ergosterols; Immunosuppressive activity; Magnetic Resonance Spectroscopy; Molecular Structure; Trichocomaceae
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2023.113785

Quadristerols A−G, seven undescribed ergosterols, were obtained from Aspergillus quadrilineata. Their structures and absolute configurations were determined based on HRESIMS, NMR, quantum-chemical calculations, and single-crystal X-ray diffraction analyses. Quadristerols A−G featured ergosterol skeletons with different attachments; quadristerols A−C were three diastereoisomers possessing a 2-hydroxy-propionyloxy group at C-6, and quadristerols D−G were two pairs of epimers with a 2,3-butanediol group at C-6. All of these compounds were evaluated for their immunosuppressive activities in vitro. Quadristerols B and C showed excellent inhibitory effects against concanavalin A-induced T lymphocyte proliferation with IC50 values of 7.43 and 3.95 μM, respectively, and quadristerols D and E strongly inhibited lipopolysaccharide-induced B lymphocyte proliferation with IC50 values of 10.96 and 7.47 μM, respectively. Quadristerols A−G, seven undescribed ergosterols, were obtained from Aspergillus quadrilineata. Quadristerols A−G featured ergosterol skeleton with different attachments: quadristerols A−C were three diastereoisomers possessing a 2-hydroxy-propionyloxy group at C-6, and quadristerols D−G were two pairs of epimers with a 2,3-butanediol group at C-6. Their configurations were determined by quantum-chemical calculations, and single-crystal X-ray diffraction analyses. [Display omitted] •Seven undescribed ergosterols, were obtained from Aspergillus quadrilineata.•Their configurations were determined by quantum-chemical calculations and X-ray diffraction analyses.•Compounds 2, 3, 4, and 6 showed excellent immunosuppressive activities.