Flavonoids and Essential Oil of Bidens cernua of Polish Origin and in Vitro Antimicrobial Activity of the Oil

Phytochemical studies of the aerial parts of Bidens cernua L. led to the isolation of six flavonoids: luteolin (1), flavanomarein (2), tilianin (3), maritimetin (4), cynaroside (5) and cosmosiin (6). The quantitative analysis of flavonoids exhibited 0.81% contents of flavonoids in flowers and 1.62% in the herb counted as a hyperoside equivalent. Total Tannins Content showed the occurrence of 7.87% in flowers and 5.83% in the herb. The chemical composition of the essential oil obtained from the herb of B. cernua was evaluated in 92.2%, which corresponds to 99 compounds. Antimicrobial activity of the essential oil was evaluated on Gram-positive, Gram-negative bacteria and fungi. The oil exhibited a strong antibacterial and antifungal activity, especially against Gram-positive bacterial strains. T his is the first time the aforementioned compound (3) has been isolated from B. cernua.