Spiropenicitrinol A: A Spirocyclic Polyketide from Penicillium citrinum with Potent Anti-inflammatory Activity

Spiropenicitrinol A (1), an intriguing 5/5/6/5 spirocyclic polyketide architecture with a unique 3H-spiro[benzo[1,2-b:4,5-b']difuran-2,1'-cyclopentane] core, was obtained from Penicillium citrinum Y12. The structure was established by spectroscopic analysis, quantum-chemical calculations, and single-crystal X-ray crystallography. 1 showed potent anti-inflammatory activity by inhibiting LPS-induced NO, TNF-α, IL-6, and IL-1β production in RAW264.7 cells. These findings indicated that this complex spirocyclic architecture could serve as a promising scaffold for the further development of novel anti-inflammatory agents.