Bonenncarpas A–K: Coumarin derivatives with anti-inflammatory activity from Boenninghausenia sessilicarpa

Eleven previously undescribed coumarin derivatives, bonenncarpas A-K (1-11), along with three known analogues (12-14), were isolated from the whole plant of Boenninghausenia sessilicarpa. The structures of these compounds were elucidated through comprehensive spectroscopic and spectrometric analyses. Their absolute configurations were determined by comparing experimental and calculated electronic circular dichroism data, as well as by X-ray crystallography. Notably, compound 1 features an open-ring coumarin structure with a five-membered lactone ring, while compounds 9-11 are characterized by a dihydrofuran ring at C-3 and C-4. All compounds were evaluated for their inhibitory effects on lipopolysaccharide-induced nitric oxide production in RAW 264.7 macrophage cells. At a concentration of 10 μM, compounds (-)-3, (+)-5, (+)-6, (+)-9, (-)-9, (+)-10, and (-)-10 exhibited inhibition of NO production, ranging from 25.5% to 95.0%.