LL-Z12711 alpha, a fungal metabolite, dose-dependently inhibited interleukin-1 beta (IL-1 beta) production in lipopolysaccharide (LPS)-stimulated human whole blood. Oral administration of LL-Z1271 alpha to LPS-challenged mice caused significant lowering in the IL-1 beta levels in peritoneal cavity. Data presented suggest that LL-Z1271 alpha inhibits IL-1 beta production by a novel mechanism as the inhibitory activity was not due to effects on caspase-1 (IL-1 beta converting enzyme), the ATP-induced release mechanism or a lysosomotrophic effect.