SOLVENT POLARITY EFFECT ON THE COMPOSITION -OF BIOLOGICALLY ACTIVE SUBSTANCES, UV SPECTRAL CHARACTERISTICS, AND ANTIBACTERIAL ACTIVITY OF EUPHRASIA BREVIPILA HERB EXTRACTS

摘要

The compositions of biologically active substances in Euphrasia brevipila Burn, et Gremli (Scrophulariaceae) extracts obtained using solvents with different polarities have been investigated. It was established that the composition of isolated substances varied depending on the extractant polarity. Only phenolcarboxylic acids were found in ether, chloroform, and ethylacetate extracts. Aqueous, ethanol, and DMSO extracts contained also flavonoids and iridoids. The difference in the compositions of biologically active substances was confirmed by UV spectral characteristics of extract solutions with added complexants. The maximum antibacterial activity with respect to Staphylococcus aureus and Escherichia coli was observed for extracts obtained using the nonpolar solvents petroleum ether and chloroform (in 1:320 dilution). The bacteriostatic activity of the extracts decreases with increasing solvent polarity in the order n-butanol-ethanol-water-DMSO.