Hordenine

Hordenine is a naturally occurring alkaloid found in a variety of plants, most commonly germinated barley (Hordeum species) from which the name is derived, and is structurally classified as a phenethylamine.^1,2 It is biosynthesized by the step-wise double methylation of tyramine .³ Hordenine binds to and activates the dopamine D₂ receptor (K_i = 13 ?M) but antagonizes D₂ receptor β-arrestin recruitment.⁴ It inhibits tyrosinase activity and expression at concentrations ≥ 50 ?M resulting in reduced melanin accumulation in human melanocytes.² Hordenine is present in significant amounts in beer and can be measured in serum in the free form, for up to 2 hours, and the glucuronidated form, for up to 6 hours, after beer consumption.⁵ This product is intended for research and forensic applications.

1.Liu, D.L., and Lovett, J.V.Biologically active secondary metabolites of barley. II. Phytotoxicity of barley allelochemicalsJ. Chem. Ecol.19(10)2231-2244(1993) 2.Kim, S.-C., Lee, J.-H., Kim, M.-H., et al.Hordenine, a single compound produced during barley germination, inhibits melanogenesis in human melanocytesFood Chem.141(1)174-181(2013) 3.Meyer, E.Separation of two distinct S-adenosylmethionine dependent N-methyltransferases involved in hordenine biosynthesis in Hordeum vulgarePlant Cell Rep.1(6)236-239(1982) 4.Sommer, T., Hübner, H., El Kerdawy, A., et al.Identification of the beer component hordenine as food-derived dopamine D2 receptor agonist by virtual screening a 3D compound databaseSci. Rep.744201(2017) 5.Steiner, I., Brauers, G., Temme, O., et al.A sensitive method for the determination of hordenine in human serum by ESI? UPLC-MS/MS for forensic toxicological applicationsAnal. Bioanal. Chem.408(9)2285-2292(2016)