FLAVONOLS HPLC ANALYSIS, IN VITRO BIOLOGICAL ACTIVITIES IN SELECTED HUMULUS LUPULUS L. GENOTYPES
Keywords:Humulus lupulus, Saaz, quercetin, kaempferol, isorhamnetin, biological activity in vitro
The Humulus lupulus L. is well known as necessary raw material for beer production. The main structural classes of chemical compounds identified from hop cones include terpenes, bitter acids, prenylated chalcones, and flavonol glycosides. They were subjects of presented work. The content of quercetin was found in the range 490 - 1092 μg/g and that of kaempferol from 218 to 568 μg/g of the dry hop cones. The content of isorhamnetin was very low in all varieties. From biological activities in vitro point of view, relative high level of inhibition activity was observed for six hop genotypes - Zlatan, Lučan, and the Oswald's clones 31, 70, 71, 72, 114 on both enzymes thrombin and urokinase, but without correlation to analyzed flavonols content. In spite of this, antioxidant activity, measured by both the BCLM and HPE methods, was found high and seem to be in correlation with content of analyzed flavonols. Particularly the Oswald's clone 114 expressed very potent biological activities. In general, obtained results indicate that hop cones are valuable material also for other application others than beer production.