Fehler! Verweisquelle konnte nicht gefunden werden. shows the concentrations of prenylflavonoids in hops and beer Tab. 8.1: Concentrations of prenylflavonoids in hops and beers XH
IXH
8-PN
6-PN
DMXH
0.48
0.008
0.002
0.007
0.12
Lager/Pilsner (USA)
9 - 34
400 - 680
13 – 17
31 – 38
Pilsner (Europe)
12 - 28
570-1 060
8 – 33
22 – 55
0 0
Porter (USA)
690
1 330
240
560
0
Porter (Europe)
n.d.
n.d.
42
n.d.
0
5
300
8
11
0
Hefeweizen (Europe)
n.d.
n.d.
10 12
n.d.
0
Ale (USA)
240
3440
110
200
0
Ale (Europe)
n.d.
n.d.
9 – 21
n.d.
0
Stout (Europe) n.d. = not detectable
340
2100
24 – 139
170
0
Hop (% TM) Beer (µg/l)
Hefeweizen (USA)
References: Stevens JF, Page JE: Xanthohumol and related prenylflavonoids from hops and beer: to your good health! Phytochem 65 (2004) 1317-1330. Stevens JF, Taylor AW, Deinzer ML: Quantitative analysis of xanthohumol and related prenylflavonoids in hops and beer by liquid chromatography-tandem mass spectrometry.J Chromatogr A832 (1999) 97-107. Rong H, Lazou K, De Keukeleire D, Milligan SR, Sandra P: Quantitation of 8-prenylnaringenin, a novel phytoestrogen in hops (Humulus lupulus L), hopproducts, and beers, by benchtop HPLC-MS using electrospray ionization. Chromatographia 51 (2000) 545-552. Schaefer O, Bohlmann R, Schleuning WD, Schulze-Forster K, Hümpel M: Development of a radioimmunoassay for the quantitative determination of 8-prenylnaringenin in biological matrices. J Agric Food Chem 53 (2005) 2881-2889.
During the wort boiling process, xanthohumol is isomerized to form iso-xanthohumol and desmethylxanthohumol to form 8- und 6-prenylnaringenin. For this reason, desmethylxanthohumol is not found in beer, and the concentrations of prenylated naringenins are much higher than in hop. The oestrogenic effect of 8-prenylnaringenin (8-PN) is due to the fact that 8-prenylnaringenin has a similar structure to the female sexual hormone 17-β-oestradiol. Soya, too, contains oestrogen-active substances, such as the isoflavones daidzein and genistein, although their activity is weaker than that of 8-PN.
122