Valorization of the Salvia officinalis L. of the Morocco bioactive extracts: Phytochemistry, antioxidant activity and corrosion inhibition

Abstract The present study aims to determine the chemical composition of Salvia officinalis L., collected in Khenifra region (Morocco), have a phytochemical screening and to evaluate its antioxidant activity, as well as its corrosion inhibiting powers using two methods: the potentiodynamic polarization and impedance spectroscopy (EIS) measurements. The phytochemical screening helped us to highlight the presence of polyphenols, catechics and Gallic tannins, flavonoids, saponins and Terpenoids. It showed that the methanolic extract was very rich in total phenols (1.044 ± 0.004 mg GAE/g of extract) and flavonoids (0.037 ± 0.003 mg EQ/g of extract). Leaves of Salvia officinalis L. were steam distilled using a Clevenger apparatus. The yield of essential oil was 4.13 ± 0.01%, and its analysis by GC–MS has identified 105 components with the dominance of Trans-Thujone (17.74%), 1,8-cineol (12.63%), Camphor (12.24%), Caryophyllene (9.87%), α-pinene (7.82%), Dehydra-Aromadendrane (7.29%), and Guaiol (7.03%). The results of antioxidant activity allowed the determination of IC50 (IC50 = 309.42 mg/ml) for the oil. The latter has shown an inhibition efficiency of 83.06% and 70.58% for the both methods respectively at a concentration of 4 g/l, the methanolic extract which has shown an inhibition efficiency of 91.62% and 49.70% respectively at the same concentration.