Glyoxylic Acid → (7R)-7-(5-Carboxy-5-oxopentanoyl)aminocephalosporinate

Beteiligte Stoffe

Reaktionsschritte

A fermentation liquor of Cephalosporium acremonium was freed from the cells by filtration, subjected to acid treatment (pH 2.8) to decompose penicillin N contained therein and then once filtered, and the residue was washed. The filtrate was combined with the washings to obtain 4.6 liters of a liquid containing 3223 γ/ml of cephalosporin C. This liquid was passed through and adsorbed on an active carbon column, washed with water and then eluted with 7 liters of 3% n-butanol containing 700 ml. of 0.3N sodium hydroxide to recover a desired fraction. This fraction was adjusted to pH 6.0 and then concentrated under reduced pressure at below 40° C. to obtain 275 ml. of a pale yellow solution containing 40 mg/ml of cephalosporin C. 100 Milliliters of this solution was adjusted to pH 6.5 by addition of sodium hydroxide and then incorporated with 2.1 g. of zinc acetate. Into the resulting liquid, 500 ml. of an aqueous solution containing 4.6 g. of glyoxylic acid and 9.6 ml. of γ-picoline was dropped over a period of 1.5 hours with stirring at room temperature. During the reaction, sodium hydroxide was added so that the pH of the reaction liquid became 5.0. In this case, a part of the reaction liquid was recovered and subjected to paper chromatography to find that the crude yields of 3-acetoxymethyl-7β-(5-carboxy-5-oxopentanamido)-3-cephem-4-carboxylic acid and 3-acetoxymethyl-7β-(4-carboxybutanamido)-3-cephem-4-carboxylic acid were 61% and 18%, respectively.

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