Carnosic acid 12-methyl ether-γ-lactone, a ferruginol-type diterpene from Salvia officinalis

Abstract A new oxygenated diterpene γ-lactone, 12-methoxy-8,11,13-abietatrien-20,11-olide, a derivative of carnosic acid (carnosic acid 12-methyl ether-γ-lactone), has been isolated from the aerial parts of Salvia officinalis , along with three other known terpenoids: manool, rosmanol 7-ethyl ether and oleanic acid. The structures of all isolated compounds were established by spectroscopic data, some chemical reactions and were substantiated by X-ray diffraction.