Content of selected polyphenolic compounds in four Sambucus nigra l. cultivars in relation to their antimicrobial activity

European elderberry (Sambucus nigra L.) fruits constitute a valuable source of biologically active compounds useful in the pharmaceutical industry. We aimed to determine the content of chosen polyphenolic compounds in fruit extracts from four cultivars of elderberry (Alleso, Korsor, Sampo, Samyl) and their relation to antibacterial and antifungal activity. The content of polyphenols was determined with the use of high-performance liquid chromatography (HPLC), while antimicrobial activity, including minimum inhibitory concentration (MIC), minimum bactericidal (MBC) or fungicidal (MFC) concentration, was studied with the use of microbroth dilution method. HPLC analysis revealed the presence of concentrations of cyanidin glycosides, caffeic and quercetin derivatives depending on the plant cultivar. The extracts exhibited the highest antibacterial activity against Staphylococcus spp. (MIC = 0.313 – 0.625 mg/mL) and Helicobacter pylori (MIC = 0.313 – 1.25 mg/mL) and antifungal against Candida albicans and C. parapsilosis (MIC = 0.313 – 2.5 mg/mL). Results showed that the concentration of cyanidin glycosides, caffeic and quercetin derivatives depended on the analyzed S. nigra L. cultivar and pointed towards a correlation between their high content and antimicrobial activity. These results support the idea that elderberry fruits contain bioactive compounds providing them significant antimicrobial potential.