Monitoring of the dopamine D2 receptor agonists hordenine and N-methyltyramine during the brewing process and in commercial beer samples

Sommer T, Dlugash G, Hübner H, Gmeiner P, Pischetsrieder M (2019)


Publication Status: Published

Publication Type: Journal article

Publication year: 2019

Journal

Publisher: ELSEVIER SCI LTD

Book Volume: 276

Pages Range: 745-753

DOI: 10.1016/j.foodchem.2018.10.067

Abstract

The phenethylamine alkaloid hordenine, present in germinated barley, was identified recently as a functionally selective dopamine D2 receptor agonist contributing potentially to the rewarding effects of drinking beer. Here, it was shown that the hordenine precursor N-methyltyramine binds with a similar affinity to the dopamine D2 receptor as hordenine (K-i 31.3 mu M) showing also selectivity towards the G protein-mediated pathway over the beta-arrestin pathway. Using a newly developed UHPLC-ESI-MS/MS method to monitor beer production, we demonstrated that hordenine and N-methyltyramine were released continuously from barley malt during mashing and were stable during fermentation and conditioning. The amounts released from different base malt types were in a similar range but tended to be higher from caramel malts. Hordenine and N-methyltyramine concentrations in 24 types of beer varied between 1.05-6.32 and 0.59-4.61 mg/L, respectively. Thus, the human uptake of the alkaloids during beer consumption is in the low milligram range.

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APA:

Sommer, T., Dlugash, G., Hübner, H., Gmeiner, P., & Pischetsrieder, M. (2019). Monitoring of the dopamine D2 receptor agonists hordenine and N-methyltyramine during the brewing process and in commercial beer samples. Food Chemistry, 276, 745-753. https://doi.org/10.1016/j.foodchem.2018.10.067

MLA:

Sommer, Thomas, et al. "Monitoring of the dopamine D2 receptor agonists hordenine and N-methyltyramine during the brewing process and in commercial beer samples." Food Chemistry 276 (2019): 745-753.

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