Z21115 is an orally active inhibitor for phosphodiesterase 4 ( PDE4 ), that inhibits PDE4D7 with IC 50 of 10.5 nM. Z21115 inhibits Lipopolysaccharide -induced expression of IL-6 , TNF-α and iNOS. Z21115 exhibits anti-inflammatory activity in DSS -induced mouse colitis models without significant toxicity (1 g/kg).