Planta Med 2011; 77 - SL52
DOI: 10.1055/s-0031-1282175

Differentiation Effects of Prenylflavanones and Chalcones present in Hops in Neuronal Tissue Cultures

C Urmann 1, E Oberbauer 2, L Aigner 2, H Riepl 3
  • 1Institute of Resource and Energy Technology, Technische Universität München, Schulgasse 16, 94315 Straubing, Germany
  • 2Institute of Molecular Regenerative Medicine, Paracelsus Medical University, Strubergasse 21, 5020 Salzburg, Austria
  • 3Chair of Organic and Analytical Chemistry, Weihenstephan-Triesdorf University of Applied Sciences, Schulgasse 16, 94315 Straubing, Germany

Hops (Humulus lupulus L.) as medicinal plant is abundant in rare polyphenols. Besides so called bitter-acids important in brewing there are chalcones like xanthohumol and flavanones. Particularly 8-prenylnaringenin, a flavanone is the most prominent prenylflavanone since it is known as a very potent phytoestrogen [1]. Besides 6- or 8-prenylnaringenin, hop extracts yield a number of minor compounds related to each other by ring closure reactions, e.g. 8-prenylnaringenin is formed from desmethylxanthohumol, so are many more. The potency of hop flavonoids to induce at least growth arrest in leucemic cell cultures is nearly equipotent and remarkable [2]. The question addressed in this work was if this effect would be observed even in neuronal neoplastic cells types since hop flavonoids may cross the blood brain barrier [3]. A commercial extract is available enriched in rare prenylflavonoids and xanthohumol. It is prepared mostly from a residue of the CO2 extraction process by solvent extraction. This material was used in a process of various chromatographic techniques to purify pairs of complementary chalcones and flavanones with identical side chains. Xanthohumol and Isoxanthohumol particularly represent such a pair to get some hint of a structure activity relationship. Growth inhibitors frequently induce differentiation in highly proliferating clones. Here some hop flavonoids appeared to be distinghuished since they may have converted proliferation into differentiation.

Acknowledgement: Wissenschaftliche Station für Brauerei in München e.V., Dr. Biendl Hallertauer Hopfenveredelungsgesellschaft m.b.H.

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