Mansoins C-F, Oligomeric Flavonoid Glucosides Isolated from Mansoa hirsuta Fruits with Potential Anti-inflammatory Activity

Continued investigation of the polyphenolic pool of the fruits of Mansoa hirsuta afforded four additional members of the new class of glucosylated oligomeric flavonoids comprising a flavanone core linked to 1,3-diarylpropane C-6-C-3-C-6 units. The structures and absolute configurations of mansoins C-F (3-6) were established by analysis of NMR and electronic circular dichroism data. Mansoin C (3) was identified as a diglucosylated heterodimer, whereas mansoins D (4), E (5), and F (6) were identified as triglucosylated heterotrimers, isomeric with mansoin A (1). Mansoin F (6) inhibited TNF-alpha release by lipopolysaccharide-stimulated THP-1 cells (IC50 of 19.3 +/- 1.3 mu M) and, as with mansoin A (1), reduced the phosphorylation levels of p-65-NF-kappa B, when assayed at 50 mu M. These results indicate that the potential anti-inflammatory properties of mansoin F (6) are probably due to inhibition of the NF-kappa B pathway and inhibition of TNF-alpha release.