Secondary metabolites, antioxidant and anti-proteinase activities of methanolic extracts from cones of hop (Humulus lupulus L.) cultivars

Abstract

Contents of polyphenols, flavonoids, bitter acids, α-bitter acids, xanthohumol, desmethylxanthohumol, essential oils, antioxidant activities, and inhibitory activities against trypsin, thrombin, urokinase, and papain were analysed in methanolic extracts prepared from the hope cones. Significant differences between extracts from eight hop cultivars in all measured parameters were found. Two cultivars—Agnus and Vital—could be designated as the very special, all possessing high content of bitter acids, α-acids, essential oils, xanthohumol, and desmethylxanthohumol. The other two cultivars—Bohemie and Sladek—had interesting inhibitory activities against analysed proteinases. Differences between cultivars were also in content of total polyphenols, total flavonoids, as well as in antioxidant activity. All analysed hop cultivars developed originally for brewing contained also secondary metabolites with valuable biological activities related to health conditions associated with antioxidant status and some pathophysiological agents of proteinase character.