Isolation of Marker Compounds from Humulus lupulus Using LC/MS-based Chemical Profiling

Humulus lupulus (hops) is a hermaphroditic plant with male and female flowers occurring in separate individuals. The ethanolic extract of hops, the female flower cones, was analyzed by LC/MS-based molecular networking (MN) approach to selectively isolate xanthohumol (1), xanthohumol D (2), xanthohumol B (3), and isoquercitrin (4) with therapeutic properties such as antimicrobial, anti-inflammatory, and antioxidant effects. Hops were extracted with 50% ethanol and 1 was sequentially isolated using various chromatographic methods. From the EtOAc fraction containing 1 identified by MN, 1 was isolated using column chromatography and characterized by LC/MS and identified by NMR analyses. We also profiled other specialized metabolites of H. lupulus by visualizing MN.