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The objective of this study was the optimization of the extraction process and the qualitative and quantitative determination of the bioactive metabolites: 12-<i>O</i>-methylcarnosic acid (12MCA), carnosic acid (CA), carnosol (CS), 7-<i>O</i>-methyl-<i>epi</i>-rosmanol (7MER) and rosmanol (RO) in infusions, decoctions, turbulent flow extracts, tinctures and oleolites from three <i>Salvia</i> species: <i>Salvia officinalis</i> L. (common sage, <i>SO</i>), <i>Salvia fruticosa</i> Mill. (Greek sage, <i>SF</i>) and <i>Salvia rosmarinus</i> Spenn (syn <i>Rosmarinus officinalis</i> L.) (rosemary, <i>SR</i>), using Quantitative Proton Nuclear Magnetic Resonance Spectroscopy (¹H-qNMR). Regarding the aqueous extracts, decoctions appeared to be richer sources of the studied metabolites than infusions among the three plants. For <i>SR</i>, the turbulent flow extraction under heating was the most efficient one. The optimum time for the preparation of decoctions was found to be 5 min for <i>SF</i> and <i>SO</i> and 15 min for <i>SR</i>. It is noteworthy that <i>SR</i> tinctures were not stable in time due to decomposition of the abietane-type diterpenes CA and CS because of the polar solvent used for their preparation. Contrary to this finding, the oleolites of <i>SR</i> appeared to be very stable. Olive oil as a solvent for extraction was very protective for the contained abietane-type diterpenes. A preliminary stability study on the effect of the storage time of the <i>SF</i> on the abietane-type diterpenes content showed that the total quantity of abietanes decreased by 16.51% and 40.79% after 12 and 36 months, respectively. The results of this investigation also demonstrated that ¹H-qNMR is very useful for the analysis of sensitive metabolites, like abietane-type diterpenes, that can be influenced by solvents used in chromatographic analysis.