CCC Sample Cutting for Isolation of Prenylated Phenolics from Hops

Abstract

One of the most potent estrogenic substances from the plant kingdom is the prenylated flavanone, 8‐prenylnaringenin (8PN), present in hops (Humulus lupulus L., Cannabaceae) in low (<10 ppm) concentrations. The prenylated chalcone desmethylxanthohumol (DMX), which is also present in this plant material, serves as a precursor to 8PN. A method for the preparative isolation of these and related bioactive phytochemicals has been developed that involves the use of multiple chromatographic techniques including complementary countercurrent chromatography (CCC) solvent systems. This paper describes the isolation of 8PN and DMX employing “sample‐cutting CCC”. The Hexanes‐EtOAc‐MeOH‐H2O (HEMWat) solvent systems found to be effective for isolation of prenylated phenolics from hops range from HEMWat 8‐2‐8‐2 for diprenylxanthohumol and 6,8‐diprenylnaringenin, to HEMWat 6‐4‐6‐4 for xanthohumol (XH), 6PN and 8PN, to HEMWat 5‐5‐5‐5 for DMX, hydroxylated derivatives of XH, and humulinones.