|
|Section2= |Section3= }} ''N''-Methylphenethylamine (NMPEA), a positional isomer of amphetamine, is a naturally occurring trace amine neuromodulator in humans that is derived from the trace amine, phenethylamine (PEA).〔 It has been detected (< 1 μg/24 hrs.) in human urine〔G. P. Reynolds and D. O. Gray (1978) ''J. Chrom. B: Biomedical Applications'' 145 137–140.〕 and is produced by phenylethanolamine N-methyltransferase with phenethylamine as a substrate.〔〔 PEA and NMPEA are both alkaloids that are found in a number of different plant species as well.〔T. A. Smith (1977). "Phenethylamine and related compounds in plants." ''Phytochem.'' 16 9–18.〕 Some ''Acacia'' species, such as ''A. rigidula'', contain remarkably high levels of NMPEA (~2300–5300 ppm).〔B. A. Clement, C. M. Goff and T. D. A. Forbes (1998) ''Phytochem.'' 49 1377–1380.〕 NMPEA is also present at low concentrations (< 10 ppm) in a wide range of foodstuffs.〔G. B. Neurath et al. (1977) ''Fd. Cosmet. Toxicol.'' 15 275–282.〕 ==Chemistry== In appearance, NMPEA is a colorless liquid. NMPEA is a weak base, with pKa = 10.14; pKb = 3.86 (calculated from data given as Kb〔W.H. Carothers, C. F. Bickford and G. J. Hurwitz (1927) ''J. Am. Chem. Soc.'' 49 2908–2914.〕). It forms a hydrochloride salt, m.p. 162–164°C.〔C. Z. Ding et al. (1993) ''J. Med. Chem.'' 36 1711–1715.〕 Although NMPEA is available commercially, it may be synthesized by various methods. An early synthesis reported by Carothers and co-workers involved conversion of phenethylamine to its ''p''-toluenesulfonamide, followed by ''N''-methylation using methyl iodide, then hydrolysis of the sulfonamide.〔 A more recent method, similar in principle, and used for making NMPEA radio-labeled with 14C in the N-methyl group, started with the conversion of phenethylamine to its trifluoroacetamide. This was N-methylated (in this particular case using 14C – labeled methyl iodide), and then the amide hydrolyzed.〔I. Osamu (1983) ''Eur. J. Nucl. Med.'' 8 385–388.〕 NMPEA is a substrate for both MAO-A (KM = 58.8 μM) and MAO-B (KM = 4.13 μM) from rat brain mitochondria.〔O. Suzuki, M. Oya and Y. Katsumata (1980) ''Biochem. Pharmacol.'' 29 2663–2667.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「N-Methylphenethylamine」の詳細全文を読む スポンサード リンク
|