Polyphenol Analysis and Antibacterial Potentials of Twig Extracts of , , and Growing Naturally in Finland.

species have been used in traditional medicine to treat fever and inflammation. However, there is no reported information on the antibacterial activities of and , and little is known about the phytochemistry of . In this study, winter-dormant twig extracts of , , and were screened for their antibacterial activities against , , , and . The antibacterial effects were evaluated using agar diffusion and turbidimetric microplate methods. Time-kill effects were measured using the microplate optical density (OD620) method. UPLC-PDA-QTOF/MS analysis was conducted to identify the polyphenols present in a methanol extract of . The antibacterial results show that methanol and hot and cold water twig extracts of , , and have significant antibacterial effects against , , and with the diameters of the inhibition zones (IZDs) ranging from 16.17 to 30.0 mm and the MICs between 1250 and 2500 µg/mL. Only the cold water extract of was moderately active against . Proanthocyanidins, procyanidin B1 (/ 577), and procyanidin C1 (/ 865) were identified as the major polyphenols present in the methanol extract of twigs for the first time. Additionally, salicin-7-sulfate was present in twigs. Procyanidin B-1, taxifolin, trans-p-hydroxycinnamic acid, and catechin showed growth inhibitory activity against with a MIC value of 250 µg/mL.