Phytochemical analysis and antimicrobial, antioxidant, and cytotoxic activities of Scorzonera aucheriana DC (Asteraceae)

Abstract

The present study is mainly focused on the isolation and structure elucidation of four new (1–4), two known astragalin (5), and kaempferol-3,7-di-O- β -D-glucopyranoside (6) from the aerial parts of Scorzonera aucheriana DC. The structures of the isolated compounds were elucidated based on 1D and 2D NMR ( 1 H, 13 C/APT, COSY, HMBC, and HSQC), UV, FT-IR, and HRESI-MS data. The total phenol and flavonoid contents and the antioxidant activity of S. aucheriana crude methanol extract and its fractions (n -hexane, chloroform, ethyl acetate, and water) were investigated. The highest antioxidant activities against DPPH and FRAP were observed in the ethyl acetate fraction of S. aucheriana . The antimicrobial activity of the methanol extract, its solvent fractions, and isolated compounds (1–6) was evaluated against 10 microorganisms. The chloroform and ethyl acetate fractions exhibited antimicrobial activity against all tested microorganisms. Compounds 1–3 , 5 , and 6 exhibited anti-tuberculosis activity with MICs ranging from 30.9 μg/mL to 250 μg/mL. Compounds 2 , 4 , and 5 have also demonstrated moderate antifungal activity, with MICs ranging from 110 μg/mL to 765 μg/mL against C. albicans , a pathogenic yeast. Compounds 1–3 showed almost no cytotoxic activity in L-929 cells.