US Patent 8003358 Two-step enzyme method for preparing 7-aminocephalosporanic acid

The present invention discloses a two-step enzyme method for preparing 7-aminocephalosporanic acid from cephalosporin C, wherein D-amino acid oxidase used is purified D-amino acid oxidase mutant of yeast Trigonopsis variabilis, having a specific activity of 105% higher than that of parent D-amino acid oxidase. The method has no need of addition of hydrogen peroxide, β-lactamase inhibitor, catalase inhibitor, catalase and the like commonly used in the prior art. The productivity of the method can reach more than 93%. Thus, the method is simple, low in cost and high in productivity.