HPLC and HPLC-MS analysis of urinary N(epsilon)-monomethyl-lysine.
Administration of (14)C-labelled L-deprenyl to rats results in the urinary elimination of a 14C-labelled compound. The 9-fluorenylmethoxycarbonyl chloride-reacted urine sample is fractionated by high-performance liquid chromatography (HPLC) on an octadecyl silica stationary phase. N(epsilon)-Monomethyl-lysine is identified in the fraction containing the majority of the radioactivity. Structural elucidation is carried out using HPLC-mass spectrometry in atmospheric pressure chemical ionization mode. Identification of the 14C-labelled fragment in Ne-monomethyl-lysine is an experimental proof that an N-methylated amino acid is generated by transmethylation from a well-known drug. This type of transmethylation may have basic importance in the positive side effects of certain drugs.
Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Nagyvárad tér 4, Hungary.
H
H
Kalász
A
A
Benkö
Z
Z
Szücsp
A
A
Szilágyi
T
T
Szarvas
J
J
Lengyel
D000818:Animals; D002250:Carbon Radioisotopes; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D008239:Lysine / Q000031:analogs & derivatives* / Q000652:urine; D013058:Mass Spectrometry; D051381:Rats; D017208:Rats, Wistar; D012642:Selegiline / Q000378:metabolism*
D002250:Carbon Radioisotopes; C005205:epsilon-N-methyllysine; D012642:Selegiline; D008239:Lysine