Study of Electrochemical Oxidation of Xanthohumol by Ultra-Performance Liquid Chromatography Coupled to High Resolution Tandem Mass Spectrometry and Ion Mobility Mass Spectrometry
- 219 Downloads
Electrochemically assisted oxidation off-line combined with UPLC/ESI–MS and ion mobility mass spectrometry enabled us to gain insight into the oxidation mechanisms of xanthohumol. Several types of monomeric oxidation products were identified, i.e., monohydroxylated and dehydrogenated derivatives and related quinones. Besides, high contents of dimers were observed. The structures of four main oxidative condensation products of two xanthohumol molecules were proposed based on combination of retention time, exact mass measurement, fragmentation pattern, data from on-line ion mobility mass spectrometric experiments and with the support of independent electrochemical experiments. To the best of our knowledge, this is the first evidence on formation of xanthohumol dimers. The effect of the pH on the generation of oxidation products was further investigated. The monomeric and dimeric oxidation products are favored at pH of 5.5 and 4.5, respectively.
KeywordsUltra-performance liquid chromatography Mass spectrometry Ion mobility Xanthohumol Prenylchalcone Oxidation Dimer
This work received financial support from the European Union (FEDER funds) under the framework of QREN through Project NORTE-07-0124-FEDER-000069). LFG wishes to thank Foundation for Science and Technology (FCT) for his Sabbatical Leave Grant (SFRH/BSAB/1272/2012). DOC wishes to acknowledge FCT for his Ph.D. studentship (SFRH/BD/79939/2011). Authors thank to the project of Ministry of Education, Youth and Sports (Project LO1305), European Social Fund OP—Education for Competitiveness (Project CZ.1.07/2.3.00/30.0041) and Grant Agency of Czech Republic (Project P206/12/1150).
Compliance with ethical standards
Conflict of interest
All authors declare no conflict of interest regarding the present work.
- 3.Magalhães PJ, Carvalho DO, Cruz JM, Guido LF, Barros AA (2009) Fundamentals and health benefits of xanthohumol, a natural product derived from hops and beer. Nat Prod Commun 4:591–610Google Scholar
- 10.Harikumar KB, Kunnumakkara AB, Ahn KS, Anand P, Krishnan S, Guha S, Aggarwal BB (2009) Modification of the cysteine residues in IkappaBalpha kinase and NF-kappaB (p65) by xanthohumol leads to suppression of NF-kappaB-regulated gene products and potentiation of apoptosis in leukemia cells. Blood 113:2003–2013CrossRefGoogle Scholar
- 12.Deeb D, Gao X, Jiang H, Arbab AS, Dulchavsky SA, Gautam SC (2010) Growth inhibitory and apoptosis-inducing effects of xanthohumol, a prenylated chalone present in hops, in human prostate cancer cells. Anticancer Res 30:3333–3339Google Scholar
- 14.Gerhäuser C, Alt A, Heiss E, Gamal-Eldeen A, Klimo K, Knauft J, Neumann I, Scherf HR, Frank N, Bartsch H, Becker H (2002) Cancer chemopreventive activity of Xanthohumol, a natural product derived from hop. Mol Cancer Ther 1:959–969Google Scholar
- 17.Yilmazer M, Stevens JF, Deinzer ML, Buhler DR (2001) In vitro biotransformation of xanthohumol, a flavonoid from hops (Humulus lupulus), by rat liver microsomes. Drug Metab Dispos 29:223–231Google Scholar
- 21.Jirasko R, Holcapek M, Vrublova E, Ulrichova J, Simanek V (2010) Identification of new phase II metabolites of xanthohumol in rat in vivo biotransformation of hop extracts using high-performance liquid chromatography electrospray ionization tandem mass spectrometry. J Chromatogr A 1217:4100–4108CrossRefGoogle Scholar
- 24.Bamforth C (2003) Beer-tap into the art and science of brewing. Oxford University Press, OxfordGoogle Scholar
- 25.Marken F, Neudeck A, Bond AM (2010) Cyclic voltammetry. In: Scholz F (ed) Electroanalytical methods. Guide to experiments and applications. Springer, BerlinGoogle Scholar