Phytochemical Composition, Antibacterial and Antioxidant Activities of the Ethanolic Root Extract of the Endemic Onosma, Northern Iran

The study investigated the antioxidant and antibacterial properties of the ethanolic root extract of Onosma dichroantha from northern Iran. The major compounds identified in the extract were phthalic acid, di(2-propylpentyl) ester (54.52%), β-sitosterol (16.65%), and ethanol, 2-(butylamino)- (13.32%). The extract showed high phenolic (139.2 mg gallic acid equivalents/g) and flavonoid (17.6 mg quercetin equivalents/g) contents. Antioxidant activity increased with higher extract concentrations, and the extract demonstrated significant antibacterial activity against 11 bacterial species, including Staphylococcus aureus and Pseudomonas aeruginosa. The findings concluded that the ethanolic root extract of O. dichroantha possessed notable antioxidant and antimicrobial activities.