PlaunotolPlaunotol is a chemical compound with the molecular formula C20H34O2. It is a diterpene that was first isolated from Croton sublyratus.OccurrencePlaunotol has been identified as present in Croton sublyratus and Croton stellatopilosus. In plants, the compound is biosynthesized by hydroxylation of geranylgeraniol, a reaction which is catalyzed by the enzyme geranylgeraniol 18-hydroxylase. A laboratory synthesis of plaunotol has been reported.PharmacologyPlaunotol has antibacterial activity against Helicobacter pylori, the bacteria that causes gastric ulcers. In Japan, plaunotol is used as a pharmaceutical drug under the trade name Kelnac for the treatment of gastritis and gastric ulcers.