Phytochemical analysis and antimicrobial activities of <i>Scrophularia oblongifolia</i> Loisel. ethyl acetate extract

Scrophularia oblongifolia belongs to the Scrophulariaceae family, commonly known as the water figwort in Iran. It has been known as a traditional medicinal plant in Iran.

This study was designed to investigate the phytochemicals and antimicrobial activity of ethyl acetate, methanol, MeOH: H2O (50:50 v/v), and n-hexane extract of Scrophularia oblongifolia aerial parts, growing in the Kangavar region in the Kermanshah province of Iran.

Compounds of ethyl acetate extract were isolated by chromatographic techniques (HPLC-PDA-MS/MS-Q-TOF) and their structures were elucidated by spectral methods (1D and 2D NMR). The antifungal and antibacterial activities of some new compounds and ethyl acetate, methanol, and n-hexane extract were evaluated.

Two new polyphenol iridoid glycosides with phenylpropanoid moiety namely scrophuloside A5 and scrophuloside A6; two known phenylpropanoid glycosides namely scrophuloside A3 and scrophuloside A4, and two known iridoid glycosides namely aucubin and harpagoside were isolated from S. oblongifolia. Pure compounds showed high antifungal activities with MIC values ranging from 0.35 to 0.74 µg/ml against C. albicans and high antibacterial activities with MIC values ranging from 0.70 to 1.48 µg/ml against G. vajinalis. n-Hexan extract showed moderate antibacterial and antifungal activity, while methanol and methanol:H2O (50:50 v/v) extract showed no antimicrobial activities.

Based on these findings, compounds isolated from S. oblongifolia have demonstrated potential antibacterial and antifungal activities.