The Isolation of Carnosic Acid 12-Methyl Ether from Salvia officinalis L. and NMR Study of Its Methyl Ester

In continuation of our studies on the chemical compositions of the aerial parts of cultivated Salvia officinalis L., we have isolated the title substance for the first time in this type of Sage. The structure of this isolated compound was established by spectroscopic data and some chemical reactions. Investigation of 1 H and 13 C NMR, homonuclear (COSY) ( 1 H- 1 H), heteronuclear (HETCOR) ( 1 H- 13 C), and selective INEPT spectra, permitted the unambiguous assignment of the 1 H and 13 C NMR spectra, what gave the possibility to resolve signals of similar natural products.