Preparation of Ng-Monoethyl-L-arginine.

NG-Monoethyl-L-arginine, a putative in vivo product after administration of the potent hepatocarcinogen L-ethionine to rats, has been chemically synthesized by coupling N-ethyl, S- methylthiopseudouronium iodide with alpha-amino-blocked L-ornithine. The structure of the compound as NG-monoethyl-L-arginine was confirmed by 13C NMR. Its elution time on an automatic amino acid analyzer, Rf values using thin-layer chromatography, and isoelectric point have been compared with those of NG-monomethyl-L-arginine.