| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for preparing isotope-labeled gultamine, asparagine or cysteine used in producing an isotope-labeled protein for NMR measurement, and to provide a prepared product. <P>SOLUTION: This method for preparing the isotope-labeled gultamine or asparagine comprises (a) reacting isotope-labeled gultamic acid or aspartic acid with an N-protecting group to form an N-protected amino acid, (b) cyclizing the N-protected amino acid to form an oxazolidinone, (c) reacting the oxazolidinone with ammonia under an amide formation condition to form a cyclic amide derivative, (d) hydrolyzing the cyclic amide derivative to form an N-protected amino acid, and (e) removing the protecting group from the N-protected amino acid to form the isotope-labeled gultamine or asparagine. Further, the isotope-labeled cysteine is provided. <P>COPYRIGHT: (C)2004,JPO</p> |
