ent-Kaurane diterpenoids from croton tonkinensis inhibit LPS-induced NF-κB activation and NO production

Abstract

Four ent-kaurane diterpenoids including two known, ent-7α,14β -dihydroxykaur-16-en-15-one (1) and ent-18-acetoxy-7α -hydroxykaur-16-en-5-one (2), and two new, ent-1β-acetoxy-7α,14β -dihydroxykaur-16-en-15-one (3) and ent-18-acetoxy-7α,14β -dihydroxykaur-16-en-15-one (4), were isolated from the leaves of Croton tonkinensis in a search for inhibitors of NF-κB activation and nitric oxide production. These ent-kauranoids inhibited LPS-induced NF-κB activation in murine macrophage RAW264.7 cells at IC50 values between 0.07 and 0.42 μM. Consistently, the ent-kauranoids markedly reduced LPS-induced NO production in a comparable concentration-dependent manner.