Abstract: The present invention relates to the hemi sulfuric acid salt of methyl (R)-2-amino-2-(cyclohexa-1,4-dien-1-yl)acetate, also trivially referred to as the hemi sulfuric acid salt of D-dihydrophenylglycine methyl ester, to a method for the preparation of said salt and to the use of said salt in the enzymatic synthesis of antibiotics.

Abstract: The present invention relates to a crystalline form of an intermediate for cefoperazone of formula (1) and to a process for the preparation thereof by enzymatic condensation of a 3?-thiosubstituted ?-lactam nucleus with a phenylglycine derivative.

Abstract: The present invention relates to a mutant prokaryotic penicillin G acylase derived from a wild-type penicillin G acylase characterized in that the mutant is having an amino acid substitution at one or more amino acid positions selected from the group consisting of amino acid positions A3, A77, A90, A144 A192, B24, B109, B148, B313, B460 and B488 according to the amino acid numbering of the Escherichia coli penicillin G acylase having the amino acid sequence depicted in SEQ ID No: 1.

Abstract: Cefodroxil monohydrate is formed by a processing which includes a) bringing an aqueous solution of cefadroxil monohydrate to a pH of between 7 to 9 with a suitable titrant; b) lowering the pH to a value of between 5 and 6.5 to obtain a suspension of cefadroxil monohydrate in crystal form; and c) isolating the cefadroxil monohydrate in crystal form from the suspension obtained in step b). The cefadroxil monohydrate thereby obtained exhibits a CIE b value of below 6, and advantageously a CIE b value of below 12 when stored at a temperature of 25° C. for at least 1 month.

Abstract: The present invention describes a process for the synthesis of a semi-synthetic ?-lactam compound from a nucleus and a side chain selected from the group consisting of D-phenylglycine and D-dihydro-phenylglycine in the form of a side chain ester and an enzyme catalyzing the coupling of the side chain ester to the nucleus characterized in that the side chain ester is not isolated as a solid intermediate.

Abstract: The invention relates to a method for preparing an optionally N-protected amino acid C-terminal ester or an optionally N-protected peptide C-terminal ester, comprising transesterifying the C-terminal t-alkyl ester of the amino acid or the C-terminal t-alkyl ester of the peptide with an alcohol (other than the t-alcohol corresponding to the t-alkyl group of the ester) in the presence of a hydrolytic enzyme (E.C. 3). The invention further relates to a method for preparing a peptide comprising coupling an activated, N-protected, amino acid C-terminal ester or an optionally N-protected peptide C-terminal ester with an optionally C-terminal protected amino acid or an optionally C-terminal protected peptide via a peptide bond, in the presence of an enzyme catalysing peptidic bond formation.

Abstract: The present invention relates to a process for the preparation of cefadroxil in crystal form, comprising a) adding an aqueous solution of cefadroxil to a crystallization vessel and a titrant to keep a pH in the crystallization vessel of between 7 to 9; and b) lowering the pH in the crystallization vessel to a value of between 5 and 6.5 to obtain a suspension of the ?-lactam compound in crystal form. The invention further relates to cefadroxil in crystal form obtainable by the process according to the present invention. The invention also relates to cefadroxil in crystal form with a CIE b value of below 12 when stored at a temperature of 25° C. for at least 1 month.

Abstract: The present invention relates to a process for the synthesis of cefaclor, which process comprises reacting 7-amino-3-chloro cephalosporanic acid (7-ACCA) with D-phenylglycine in activated form (PGa) in the presence of an enzyme in a reaction mixture to form cefaclor, wherein at least part of 7-ACCA and/or PGa are added to the reaction mixture during the course of the reaction. The invention also relates to an aqueous mixture comprising an amount of cefaclor of >10 (w/w) %, an amount of 7-amino-3-chloro cephalosporanic acid of <2 (w/w) %, and an amount of D-phenyl glycine of <2 (w/w) % and a process for the recovery of cefaclor from this aqueous mixture. The invention also relates to cefaclor in crystal form having an absorbance at 400 nm (A400) of less than 0.250.

Abstract: The present invention relates to a mutant prokaryotic penicillin G acylase derived from a wild-type penicillin G acylase characterized in that the mutant is having an amino acid substitution at one or more amino acid positions selected from the group consisting of amino acid positions A3, A77, A90, A144 A192, B24, B109, B148, B313, B460 and B488 according to the amino acid numbering of the Escherichia coli penicillin G acylase having the amino acid sequence depicted in SEQ ID No: 1.

Abstract: The present invention describes a process for the synthesis of an amino acid methyl ester comprising the following steps: (a) refluxing a reaction mixture comprising a free amino acid, methanol and a strong acid; (b) concentrating the mixture; (c) adding methanol; (d) repeating steps a-c one or more times.

Abstract: The present invention describes a process for the synthesis of a semi-synthetic ?-lactam compound from a nucleus and a side chain selected from the group consisting of D-phenylglycine and D-dihydro-phenylglycine in the form of a side chain ester and an enzyme catalyzing the coupling of the side chain ester to the nucleus characterized in that the side chain ester is not isolated as a solid intermediate.

Abstract: The invention relates to a method for preparing an optionally N-protected amino acid C-terminal ester or an optionally N-protected peptide C-terminal ester, comprising transesterifying the C-terminal t-alkyl ester of the amino acid or the C-terminal t-alkyl ester of the peptide with an alcohol (other than the t-alcohol corresponding to the t-alkyl group of the ester) in the presence of a hydrolytic enzyme (E.C. 3). The invention further relates to a method for preparing a peptide comprising coupling an activated, N-protected, amino acid C-terminal ester or an optionally N-protected peptide C-terminal ester with an optionally C-terminal protected amino acid or an optionally C-terminal protected peptide via a peptide bond, in the presence of an enzyme catalysing peptidic bond formation.

Abstract: The present invention describes a process for the synthesis of an amino acid methyl ester comprising the following steps: (a) refluxing a reaction mixture comprising a free amino acid, methanol and a strong acid; (b) concentrating the mixture; (c) adding methanol; (d) repeating steps a-c one or more times.

Abstract: The present invention relates to a process for preparation of a pharmaceutically acceptable metal salt of clavulanic acid comprising the steps of (a) fermenting of a microorganism capable of producing and excreting the clavulanic acid into the broth; (b) removing biomass and other solid material from the clavulanic acid containing fermentation broth obtained in step (a); (c) acidifying the solution obtained after step (b) to a pH between 1 and 3 and extracting the acidified solution with a partly or fully water-immiscible solvent and separating the clavulanic acid containing extract; (d) mixing the clavulanic acid containing extract obtained in step (c) with a metal donor and at least one additional cosolvent to result in an insoluble, preferably crystalline metal clavulanate salt with a yield of at least 80%; and (e) separating the insoluble, preferably crystalline, metal clavulanate salt from the mixture obtained in step (d).

Abstract: The present invention relates to a process for the preparation of cefadroxil in crystal form, comprising a) adding an aqueous solution of cefadroxil to a crystallisation vessel and a titrant to keep a pH in the crystallisation vessel of between 7 to 9; and b) lowering the pH in the crystallisation vessel to a value of between 5 and 6.5 to obtain a suspension of the ?-lactam compound in crystal form. The invention further relates to cefadroxil in crystal form obtainable by the process according to the present invention. The invention also relates to cefadroxil in crystal form with a CIE b value of below 12 when stored at a temperature of 25° C. for at least 1 month.

Abstract: The present invention describes a process for preparing cephradine, said process comprising reacting 7-aminodesacetoxy cephalosporanic acid (7-ADCA) with D-dihydrophenylglycine in activated form (DHa) in the presence of an enzyme in a reaction mixture to form cephradine, resulting in a conversion of 7-ADCA into cephradine of at least 70%, wherein the concentration D-dihydrophenylglycine (DH) in the reaction mixture is below 2 wt.%, wherein the conversion of 7-ADCA into cephradine & equals; (nCEF/n7-ADCA)*100%, wherein nCEF=quantity of cephradine formed (in mole); and n7-ADCA=total quantity of 7-ADCA added to reaction mixture (in mole).

Abstract: Process for the preparation of a diasteromerically enriched phenylglycine amide derivative in which an enantiomerically enriched phenylglycine amide is converted into the corresponding Schiff base with the aid of compound R2—C(O)—R3, and the Schiff base obtained is subsequently converted into the diastereomerically enriched phenyglycine amide derivative with the aid of a cyanide source, a reducing agent or an allyl organometallic compound. The phenylglycine amide derivatives obtained are interesting starting materials for the preparation of for example enantiomerically enriched &agr;- and or &bgr;-amino acids and derivatives thereof, such as amides and esters, and amines.

Abstract: Process for the preparation of a diasteromerically enriched phenylglycine amide derivative in which an enantomerically enriched phenylglycine amide is converted into the corresponding Schiff base with the aid of compound R2—C(O)—R3, and the Schiff base obtained is subsequently converted into the diastereomerically enriched phenyglycine amide derivative with the aid of a cyanide source, a reducing agent or an allyl organometallic compound. The phenylglycine amide derivatives obtained are interesting starting materials for the preparation of for example enantimerically enriched &agr;- and or &bgr;-amino acids and derivatives thereof, such as amides and esters, and amines.

Abstract: Process for the preparation of a &bgr;-lactam antibiotic in which a &bgr;-lactam nucleus is subjected to an enzymatic acylation reaction with the aid of an acylation agent at a molar ratio of acylation agent/&bgr;-lactam nucleus of less than 2.5, with the acylation agent and/or the &bgr;-lactam nucleus being supersaturated in the reaction mixture during at least part of the acylation reaction. In the process, a concentrated slurry or solution, for instance, of the &bgr;-lactam nucleus and/or the acylation agent with a different pH or a higher temperature than the pH or temperature at which the acylation reaction is carried out is added to the reaction mixture during the acylation reaction. Both the &bgr;-lactam nucleus and the acylation agent may be supersaturated in the reaction mixture.