Synthesis and evaluation of L-cystathionine as a standard for amino acid analysis.
L-Cystathionine is a key nonprotein amino acid related to metabolic conditions. The quantitative determination of L-cystathionine in physiological fluids by amino acid analysis is important for clinical diagnosis; however, certified reference material for L-cystathionine with satisfactory purity, content, and quantity has been unavailable until recently. Consequently, a practical and simple method for the preparation of L-cystathionine was examined, which involves thioalkylation of N-tert-butoxycarbonyl-L-cysteine tert-butyl ester, derived from L-cystine, with (2S)-2-(tert-butoxycarbonyl)amino-4-iodobutanoic acid tert-butyl ester, derived from L-aspartic acid, to obtain L-cystathionine with protecting groups, followed by single-step deprotection under mild conditions. This method produces L-cystathionine in high purity (99.4%) and having sufficient percentage content according to amino acid analysis, which could be used as a standard for the amino acid analysis of physiological fluids.
a Institute for Innovation, Ajinomoto Co., Inc. , Kawasaki , Japan.
Yusuke
Y
Amino
a Institute for Innovation, Ajinomoto Co., Inc. , Kawasaki , Japan.
Yumiko
Y
Suzuki
D060326:Chemistry Techniques, Synthetic; D019963:Clinical Chemistry Tests / Q000592:standards*; D003540:Cystathionine / Q000032:analysis* / Q000138:chemical synthesis* / Q000737:chemistry; D012015:Reference Standards
D003540:Cystathionine
amino acid analysis; certified reference material; clinical diagnosis; cystathionine; thioalkylation