Parallel synthesis and anti-inflammatory activity of cyclic peptides cyclosquamosin D and Met-cherimolacyclopeptide B and their analogs.

We report the parallel synthesis of two natural cyclopeptides, isolated from the seeds of Annona squamosa, cyclosquamosin D (A1), and Met-cherimolacyclopeptide B (B) and their analogs. All of the compounds were screened for anti-inflammatory activity by evaluating their inhibitory effects on the production of pro-inflammatory cytokines using the lipopolysaccharide stimulated macrophage J774A.1 cell line. Compounds having significant anti-inflammatory activity in suppressing the secretion of IL-6 and TNF-α have been identified, some of which exhibit activity superior to that observed with the natural products.