Sarcanolides C–E: three new lindenane sesquiterpenoid dimers with anti-inflammatory activities from Sarcandra glabra

Abstract

Three new lindenane-type sesquiterpenoid dimers, sarcanolides C–E (1–3), were isolated from the roots of Sarcandra glabra. Sarcanolide C (1) possesses a unique decacyclic scaffold with an unusual orthoformate unit. The structures of 1–3 were determined through extensive spectroscopic analysis, while their absolute configurations were determined by comparison of calculated and experimental electronic circular dichroism (ECD) spectra. Compounds 1–3 were evaluated for their inhibitory activity against LPS-induced nitric oxide (NO) production in RAW264.7 macrophages. All the isolates displayed a moderate inhibitory effect against NO production with IC₅₀ values in the range of 13.4–17.2 μM, comparable to that of the positive control L-NMMA.