Immunosuppressive steroids quadrilisteroids A−C and derivatives from the terrestrial fungus Aspergillus quadrilineatus

• Published in: Phytochemistry (Oxford) 2024-05, Vol.221, p.114044-114044, Article 114044
• Main Authors: Chen, Yu, Li, Qin, Liang, Yu, Wei, Mengsha, Liao, Hong, Fu, Aimin, Sun, Weiguang, Chen, Chunmei, Zhu, Hucheng, Zhang, Yonghui
• Format: Article
• Language: English
• Subjects: Absolute configuration; Eurotiaceae Aspergillus quadrilineatus; Immunosuppressive activity; Steroids
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2024.114044

Seven undescribed compounds (1−7) along with six known compounds (8−13) were isolated from Eurotiaceae Aspergillus quadrilineatus. Their structures and absolute configurations were elucidated by NMR, HRESIMS, and ECD calculations. Quadrilisteroids A (1) and B (2) possessed an unprecedented 6/5/6/6/6/5 hexacyclic ring system in conjugation with a highly fused benzene ring, while quadrilisteroid C (3) featured a surprising 6/6/6/5/5-fused carbocyclic skeleton. Quadrilisteroid C (3) exhibited potent inhibitory activity against LPS-induced proliferation of B lymphocyte cells with an IC50 value of 1.03 μM. Compound 4, demonstrated inhibitory activity against Con A-induced proliferation of T lymphocyte cells with IC50 values of 6.42 μM. [Display omitted] •Seven undescribed compounds were isolated from Aspergillus quadrilineatus.•Quadrilisteroids A and B possessed an unprecedented 6/5/6/6/6/5 hexacyclic ring system fused benzene ring.•Quadrilisteroid C exhibited great immunosuppressive activity.