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Aspersecosteroids A and B, Two 11(9 → 10)- abeo-5,10-Secosteroids with a Dioxatetraheterocyclic Ring System from
Bin-Bin Gu1, Wei Wu1, Fu-Rong Jiao1
1Research Center for Marine Drugs, State Key Laboratory of Oncogenes and Related Genes, Department of Pharmacy, Ren Ji Hospital, School of Medicine , Shanghai Jiao Tong University , Shanghai 200127 , People's Republic of China.
Abstract:
Two 11(9 → 10)- abeo-5,10-secosteroids possessing an unprecedented dioxatetraheterocyclic ring system, aspersecosteroids A (1) and B (2), and a new ergosteroid, asperflosterol (3), were isolated from the sponge-derived fungus Aspergillus flocculosus 16D-1. Their structures were determined by spectroscopic analysis, X-ray diffraction, and computational methods. Compounds 1-3 demonstrated inhibitory effects on key pro-inflammatory cytokine production in THP-1 cells. A biogenetic pathway with oxidative cleavage, Wagner-Meerwein rearrangement, and sequential acetalization as key steps is proposed for 1 and 2.
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