Phytochemical Study and Antioxidant Activities of the Water-Soluble Aerial Parts and Isolated Compounds of subsp. (Desf.) Greuter & Burdet.

Objectives: The present study aimed to determine the phenolic compounds present in the water-soluble extracts of subsp. using high pressure liquid chromatography-time-of-flight mass spectrometry (MS). These phenolic compounds were further isolated and characterized for their antioxidant activities.

Materials And Methods: The aerial parts of subsp. were air dried, powdered, and extracted using water:methanol three times. The concentrated hydromethanolic extract was further dissolved in HO, filtered, and successively extracted using ethyl acetate, chloroform, and -butanol. extracts were further purified using column chromatography, and the purified extracts were subjected to antioxidant assays.

Results: Two previously undescribed compounds, namely methyl 2,3,5,6-tetrahydroxybenzoate and 4-hydroxy-5-methoxy-2-oxo-2H-pyran-3-carboxylic acid, and 14 known compounds, including 3 flavonoids; namely 3',5,5',7-tetrahydroxyflavanone, luteolin, and isorhamnetin-3-O-β-glucoside; a sterol glucoside named daucosterol; and 10 phenolic compounds, namely salicylic acid, ferulic acid, pluchoic acid, ethyl caffeate, methyl caffeate, protocatechuic acid, rosmarinic acid, p-coumaric acid, tyrosol, and protocatechuic aldehyde, were isolated from ethyl acetate and -butanol extracts. The isolated compounds were characterized using 1D-2DHC nuclear magnetic resonance and MS methods.

Conclusion: The compounds isolated from ethyl acetate and n-butanol extracts exhibited excellent antioxidant and 2,2-diphenyl-1-picrylhydrazyl scavenging activities. All these results highlighted the antioxidant potential of the isolated phenolic compounds and extracts, which could be further utilized for different pharmacological applications.