LAUSR

We investigated the phytochemical profiles, antioxidant and antimicrobial with antibiofilm activities of methanol and ethyl acetate extracts from the whole plant of Potentilla visianii (Vis. et Panč.) Panč. The major compounds were: epicatechin and quercetin in both extracts. Total phenolic content was determined using spectrophotometric method with Folin-Ciocalteu reagent, the concentration of flavonoids with aluminum chloride and amount of tannins with butanol-HCl reagent. The methanol extract has a significantly higher yield, as well as the content of total phenols and condensed tannins. The antioxidant activity was monitored spectrophotometrically and expressed in terms of IC50 (for methanol extracts 23.8 μg/mL). In vitro antimicrobial activity was investigated by microdilution method against 17 microorganisms. The best results for MIC <0.02 mg/mL showed ethyl acetate extract against Staphylococcus aureus. The antifungal activity of extracts on Penicillium chrysogenum was in the range of positive control. The influence on biofilm formation and preformed biofilm was different. Escherichia coli ATCC 25922 and Bacillus subtilis ATCC 6633 were more sensitive as formed biofilms. S. aureus ATCC 25923 could be influenced by extracts only during the biofilm formation.