Identification and determination of biologically active substances of sage (Salvia officinalis L.), obtained under subcritical extraction conditions

Abstract

The object of this study were sage leaves (Salvia officinalis L.) of the brand «Zelyonaya apteka»,
purchased at the store Travy Kavkaza in Goryachy Klyuch. This paper focuses on the applicability of an alternative method of extraction, identification, and determination of biologically active compounds of herbs
by means of subcritical extraction. The aim of the study was to analyse the component composition of biologically active compounds of sage, obtained by subcritical extraction. The subcritical extraction of biologicallyactive compounds of sage (Salvia officinalis L.) was performed using deionized water and 70% ethanolat the temperature of 100 to 250 °С. The chromatographic determination of analytes in the sage extract was carried out by means of gas chromatography–mass spectrometry and liquid chromatography–mass spectrometry together a with solid-phase concentration technique. The analytes were then identified using standard samples and individual compounds. The conditions for the subcritical and solid-phase extraction of essential oil compounds and phenolic compounds from sage extract were optimised. The optimal temperature for extracting essential oil compounds from sage is 200 оС. Higher temperatures result in degradation of the studied compounds and a lower effectiveness of extraction. The analytes were extracted into organic phase by means of solid-phase extraction using Strata C18-E, Strata X, and Oasis HLB sorbents. Essential oil compounds and phenolic compounds in the organic phase were obtained by subcritical extraction at an elevated temperature and pressure. The identified component composition of the extract obtained by subcritical extraction differs significantly from that of the compounds obtained by means of traditional hydrodistillation. It was determined  that sage contains 52 essential oil compounds. As opposed to hydrodistillation, subcritical extraction allowed for concurrent extraction of phenolic compounds: cinnamic acids, flavonoids, and anthocyanins, as well as diterpenes. An advantage of the proposed method is that it allows the concurrent extraction and identification of essential oil compounds and phenolic compounds. The results of these study are of great interest for chemical studies of medicinal plant raw material.