Abstract: In the present invention new compounds of formula II, in enantiomerically enriched forms, are described for the first time, where R1 is chloroalkyl. The present invention also includes several new enzymatic processes for the resolution of the enantiomers of the aforementioned carbonates of formula II from the corresponding racemic mixture. The transformation of these carbonates into zopiclone enantiomerically enriched, constitutes an additional aspect of the invention.

Abstract: Enzymatic process for the preparation of cephalosporanic 7&bgr;-(4-carboxybutanamide) acid by using the modified enzyme D-aminoacid oxidase of Trigonopsis variabilis produced in Escherichia coli. The process for the expression of the enzyme comprises: (I) isolating the DNA corresponding to gene which codes for the enzyme D-aminoacid oxidase; (II) removing the intron which is contained in said gene; (III) inserting the DNA fragment obtained into the plasmide which is capable of replication in Escherichia coli; (IV) fusing at the extremity 5′ of the structural region of the gene a synthetic assembler which contains a nucleotide sequence which codes for six histidines; (V) transforming a strain of Escherichia coli with the resulting recombinant plasmide; (VI) cultivating the transformed cells of Escherichia coli; and (VII) recovering the enzyme D-aminoacid oxidase of the former cultivation operation through affinity chromatography.

Abstract: Enzymatic process for the preparation of cephalosporanic 7?-(4-carboxybutananude) acid by using the modified enzyme D-aminoacid oxidase of Trigonopsis variabilis produced in Escherichia coli. The process for the expression of the enzyme comprises: (I) isolating the DNA corresponding to gene which codes for the enzyme D-aminoacid oxidase; (II) removing the intron which is contained in said gene; (III) inserting the DNA fragment obtained into the plasmide which is capable of replication in Escherichia coli; (IV) fusing at the extremity 5′ of the structural region of the gene a synthetic assembler which contains a nucleotide sequence which codes for six histidines; (V) transforming a strain of Escherichia coli with the resulting recombinant plasmide; (VI) cultivating the transformed cells of Escherichia coli; and (VII) recovering the enzyme D-aminoacid oxidase of the former cultivation operation through affinity chromatography.

Abstract: A procedure for producing a modified 7.beta.-(4-carboxybutanamide) cephalosporinase enzyme which can be purified in a single chromatographic step. The procedure for production of the enzyme involves: mutagenizing the gene which codes for the enzyme from Acinetobacter sp. ATCC 53891 by inserting a nucleotide sequence coding for six histidine residues; fusing the mutant gene with high-efficiency promoter DNA sequences; transforming Escherichia coli cells with the fusion gene construct; growing the transformed Escherichia coli cells; and recovering the enzyme by the use of supports which contain metal chelates. 7-Aminocephalosporanic acid is an important intermediate for the manufacture of a wide range of antibacterial agents of the cephalosporin family.