Open AccessEstrogens and Congeners from Spent Hops (Humuluslupulus)
Author(s) -
Lucas R. Chadwick,
Dejan Nikolić,
Joanna E. Burdette,
Cassia R. Overk,
Judy L. Bolton,
Richard B. van Breemen,
Roland Fröhlich,
Harry H. S. Fong,
Norman R. Farnsworth,
Guido F. Pauli
Publication year - 2004
Publication title -
journal of natural products
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.976
H-Index - 139
eISSN - 1520-6025
pISSN - 0163-3864
DOI - 10.1021/np049783i
Subject(s) - xanthohumol , humulus lupulus , chalcone , chemistry , stereochemistry , isomerization , nmr spectra database , methanol , two dimensional nuclear magnetic resonance spectroscopy , hop (telecommunications) , organic chemistry , spectral line , computer network , physics , food science , pepper , astronomy , computer science , catalysis
Estrogenicity-directed fractionation of a methanol extract of the strobiles of Humulus lupulus that had been extracted previously with supercritical CO(2), known as "spent hops", led to the isolation and identification of 22 compounds including 12 prenylated chalcones (1-8, 10-13), five prenylflavanones (14-17), 4-hydroxybenzaldehyde (18), sitosterol-3-O-beta-glucopyranoside (19), humulinone (20), and cohumulinone (21). In addition, the prenylated chalcone xanthohumol C (9a) was obtained as a 6:1 mixture along with its 1' ',2' '-dihydro derivative (9b). Three new chalcones (4, 11, 12) and four previously unreported constituents of hops (5, 6, 9b, 13) are reported. The structures of the new compounds were determined through a combination of spectrometric techniques including 1D and 2D NMR, HRESIMS, and ESIMS-MS. Full 1H NMR spin system analyses were performed to characterize the higher-order glucopyranosyl, prenyl, and chalcone B-ring spectra of the isolates. The principle estrogen 8-prenylnaringenin (15) from hops is an artifact formed along with its positional isomer 6-prenylnaringenin (16) through the spontaneous isomerization of the pro-estrogenic chalcone DMX (7).