Synthesis of Benzannulated Spiroketals Derived From Stigmasterol and Sitosterol by Pd-Catalyzed Spirocyclization. NMR and X-ray Characterization. Evaluation of Cytotoxicity and Anti-Inflammatory Activity

Abstract

Five new benzannulated steroid spiroketals were synthesized by Pd-catalyzed spiroketalization of 5α and 5β-alkynediols derived from stigmasterol and sitosterol. The detailed nuclear magnetic resonance (NMR) and X-ray characterization of the newly obtained spiroketals are presented. While the obtained compounds showed null or very low cytotoxicity, two of them inhibited more than 60% of the nitrous oxide production in J774A.1 macrophages stimulated with LPS, showing promising properties as anti-inflammatory agents.