Chemical composition, antioxidant and antibacterial activities of essential oil and methanol extract of Artemisia vulgaris and Gaultheria fragrantissima collected from Nepal

Objective: To identify the chemical constituents and biological activities of essential oil and crude methanol extract of Artemisia vulgaris (A. vulgaris) and Gaultheria fragrantissima (G. fragrantissima). Methods: Phytochemical screening, total phenolic and flavonoid content, antibacterial activities, anti-oxidant assay of the crude extract were carried out to identify the biological activities and phytonutrients present in the extract. Furthermore, the chemical constituents present in the essential oil and crude methanol extract were analyzed using gas chromatography mass spectroscopy and high performance liquid chromatography (HPLC) analysis. Results: Gas chromatography mass spectroscopy analysis of essential oil from the aerial part of A. vulgaris revealed 24 different compounds in it. Sabinene (11.29%), beta-thujone (19.19%), chrysanthenone (4.48%), camphor (11.89%), borneol (4.44%) and germacrene D (8.42%) were the major compounds. Similarly, leaves of G. fragrantissima contained methyl salicylate (95%) and asarone (4.64%). Furthermore, methanol extract of leaves of A. vulgaris and G. fragrantissima were found rich in the total flavonoids and phenolic content. HPLC analysis of the methanol extract of leaves A. vulgaris revealed the presence of morin and luteolin, whereas rutin was found as a major flavonoids compound in the leaves of G. fragrantissima. Further, methanol extract of the A. vulgaris and G. fragrantissima showed the highest antioxidant and antibacterial properties compared to the essential oil. Conclusions: The HPLC analysis of the methanol extract of A. vulgaris shows the presence of luteolin and morin, whereas G. fragrantissima reveals the presence of rutin and a glycosylated flavonoids. Results reveal that A. vulgaris oil is the rich source of monoterpene and sesquiterpene compounds. Furthermore, A. vulgaris and G. fragrantissima are the rich source of the phenolic and flavonoids compounds and show good antioxidant and antibacterial activity.