Determination of the Hop-Derived Phytoestrogen, 8-Prenylnaringenin, in Beer by Gas Chromatography/Mass Spectrometry

Abstract

A method was developed to determine 8-prenylnaringenin, a novel hop-derived phytoestrogen, in beer. Matrix purification involved solid-phase extraction on octadecyl silica followed by liquid/liquid extraction on a ChemElut 1010 column connected to a Florisil adsorption/desorption cartridge. 8-Prenylnaringenin was eluted from the tandem columns using a 1:1 mixture of diethyl ether and ethyl acetate and subsequently determined as tris(trimethylsilyl) ether by GC/MS-SIM. The recovery of 8-prenylnaringenin in beer samples was between 61.1 +/- 6.6 and 82.2 +/- 8.8% for levels of 37 and 92.5 microg L(-1), respectively, and the detection limit was approximately 5 microg L(-1). Although most beers do not contain 8-prenylnaringenin in detectable quantities, the highest concentration found was 19.8 microg L(-1). The concentration of 8-prenylnaringenin in beers and, possibly, its absence depend on the selection of particular hop varieties, the hopping rate, or the type of hop product used in brewing. The efficiency of transfer of 8-prenylnaringenin from hops to beer is between 10 and 20%.

The content of hop prenylflavonoids in czech and foreign beers.

“…Analýza prenylflavonoidů metodou HPLC ve spojení s UV detektorem je možná pouze pro XN a IX po zakoncentrování analytů extrakcí na pevné fázi [17]. Originální postup stanovení 8-prenylnaringeninu po derivatizaci metodou plynové chromatografie publikoval Tekel [18].…”

“…The determination of prenylflavonoids by HPLC equipped with a UV-detector is possible only for xanthohumol and isoxanthohumol namely after concentration of the analyte by means of solid phase extraction [17]. An imaginative approach for the determination of 8-prenylnaringenin by GC after a derivatisation was published by Tekel [18].…”

Prenylated Flavonoids as Valuable Biologically Active Compounds from Hops

“…The content of 8-prenylnaringenin during beer production depends on the variety of hops, the climate, the growing conditions and the storage (Karabin et al, 2015). It was found that the concentration of 8-prenylnaringenin in beer reaches from 10 to 20 % of its original content in hops (Tekel' et al, 1999).…”

“…Při výrobě piva je obsah 8-prenylnaringeninu závislý na odrůdě chmele, klimatu, podmínkách pěstování a skladování (Karabin et al, 2015). Bylo zjištěno, že koncentrace 8-prenylnaringeninu v pivu odpovídá 10 -20 % z původního množství této látky ve chmelu (Tekel' et al, 1999).…”

Microbial Sulfation of 8-Prenylnaringenin

“…its content in beer is up to 240 mg/L (Tekel et al, 1999). Due to its strong estrogenic activity, this compound may be considered a more natural alternative to classical hormone replacement therapy (HRT) (Rad et al, 2006).…”