Discovery, Total Synthesis, and Anti‐inflammatory Evaluation of Naturally Occurring Naphthopyrone‐Macrolide Hybrids as Potent NLRP3 Inflammasome Inhibitors

Numerous clinical disorders have been linked to the etiology of dysregulated NLRP3 (NACHT, LRR, and PYD domain-containing protein 3) inflammasome activation. Despite its potential as a pharmacological target, modulation of NLRP3 activity remains challenging. Only a sparse number of compounds have been reported that can modulate NLRP3 and none of them have been developed into a commercially available drug. In this research, we identified three potent NLRP3 inflammasome inhibitors, gymnoasins A-C (1-3), with unprecedented pentacyclic scaffolds, from an Antarctic fungus Pseudogymnoascus sp. HDN17-895, which represent the first naturally occurring naphthopyrone-macrolide hybrids. Additionally, biomimetic synthesis of gymnoasin A (1) was also achieved validating the chemical structure and affording ample amounts of material for exhaustive bioactivity assessments. Biological assays indicated that 1 could significantly inhibited in vitro NLRP3 inflammasome activation and in vivo pro-inflammatory cytokine IL-1β release, representing a valuable new lead compound for the development of novel therapeutics with the potential to inhibit the NLRP3 inflammasome.