Glyoxylic Acid → 3,4-Diaminobenzoic acid

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Reaction Steps

Forty mg of Met-NT-3 having methionine at its N-terminal obtained in Reference Example 3 was dissolved in 4 ml of 3 M urea solution. To the mixture was added a solution containing 50 mM copper sulfate 0.5 ml, glyoxylic acid 0.25 g and pyridine 0.5 ml and allowed to stand at 25° C. for 1 hour. The reaction solution was passed through Sephadex G-25 column (25 mmID×600 mmL) equilibrated with 2.5 M urea and 50 mM phosphate buffer solution (pH 6.0) and the column was washed with the same buffer solution at 6 ml/minute of flow rate to collect the fraction of diketone derivative of Met-NT-3. To this fraction was added the same volume of 4 M acetic acid-4 M sodium acetate solution and then added 3,4-diaminobenzoic acid to give a final concentration of 40 mM, followed by vacuum and sealing with nitrogen gas, and the reaction was proceeded at 37° C. for 15 hours. The reaction solution was purified by the same method as described in Working Example 37 to obtain a purified NT-3.

Provenance & Evidence