Xanthohumol content in Lithuanian hop (Humulus lupulus L.) varieties

Abstract

Hop (Humulus lupulus L.) is a dioecious perennial plant which is probably the most frequently used in brewery. However recently hops are analyzed for their potential application in pharmaceutical industry, because hops have various compounds which have antibacterial, anticancer, radical scavenging, peroxide reducing and antioxidant properties [1, 2]. Xanthohumol is a flavonoid, which is found only in hops, recently gained a particular interest of scientists, because it has shown strong anticancer and antioxidant effects. Xanthohumol is mostly found in the cones of hops, but literature data, shows that there is a lower amount of this compound in the leaves of hops [3]. The studies of biologically active compounds in leaves of hops would probably allow to find more applications of hop harvest as a big amount of hop leaves that are harvested each year are assumed to be almost useless. The composition of biologically active compounds depends on the part of the plant, location of cultivar, variety and phase of vegetation. The composition of volatile compounds [4] and concentration of bitter α-acids of Lithuanian hop varieties were analyzed previously [5]. The aim of this study was to evaluate and compare concentration of xanthohumol in leaves and cones of H. lupulus L. plant growing in Kaunas Botanical Garden of Vytautas Magnus University, Lithuania. To our knowledge, there is no data about xanthohumol content in Lithuanian hop varieties. The concentration of xanthohumol was analyzed using high performance liquid chromatography method under isocratic conditions [6]. Results were expressed as percent of xanthohumol in dry weight of plant material. The concentration of xanthohumol in the samples of cones varied between 0.1181–0.2136 % (RSD did not exceed 3.8 %) while the concentration in the leaves was up to 84 times lower.