摘要:
The present invention describes a process for the synthesis of a semi-synthetic β-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.
摘要:
The present invention discloses Escherichia coli expression vector, as well as a method for steadily, high-efficiently expressing a required target protein in E. coli using the expression vector. The expression vector is constructed from vector pRSET-A, wherein ampicillin resistance gene in said vector pRSET-A is replaced by kanamycin resistance gene. The expression vector can be used to high-efficiently express enzymes required for the production of 7-aminocephalosporanic acid, meanwhile it does not produce β-lactamase by which the productivity of 7-aminocephalosporanic acid is reduced. The present invention also discloses two expression vectors, i.e., one expression vector pHS-GHA whose gene product is D-amino acid oxidase mutant GHA, and another expression vector pT7-kan-ACY whose gene product is glutaryl-7-aminocephalosporanic acid acylase of Pseudomonas sp. SE83.
摘要:
A process for preparing cephalosporanic acid derivatives comprises the steps of enzymatically converting a 3-thiolated cephalosporin C compound of formula (III) into a 3-thiolated-α-ketoadipyl-7-aminocephalosporanic acid derivative of formula (IV), wherein R is a heterocyclic group comprising at least a nitrogen atom. Compounds of formula (IV) are used in the preparation of cephalosporin C antibiotics and derivatives thereof.
摘要:
Process for producing the enzyme D-amino acid oxydase of Rhodotorula gracilis in host cells. The process for the expression of the enzyme comprises isolating the complementary DNA corresponding to the messager RNA of the gene which codes for the D-amino acid oxydase of any strain of Rhodotorula gracillis producing said enzyme; fusing the fragment of DNA which codes for D-amino acid oxydase of Rhodotorula gracillis with a DNA sequence which contains a site of union to the ribosome and a high efficiency promoter sequence for the express of genes in host cells; inserting the DNA fragment into a plasmid appropriate for the host cell; cultivating the host cells transformed with said plasmid; and collecting the enzyme.
摘要:
Deacetoxycephalosporin C synthase obtained from cell-free extracts of Streptomyces clavuligerus was purified to near homogeneity and characterized in inactive form. The amino acid sequence was determined and the synthase recombinantly reproduced in active form in E. coli . The recombinantly produced synthase is provided in about 97% pure form by a chromatographic process. The synthase lacks DAOC hydroxylase function; however, it possesses the ability to transform 3-exomethylenecephalosporin C to deacetylcephalosporin C.
摘要:
A peptide precursor of the ACV (aminoadipyl-cysteinyl-valine) type, in which the valine moiety may be replaced by any readily available amino acid may be converted into a cephalosporin of the type where R 1 is H, lower alkyl or functionalized carboxylic group and R 2 is H or lower alkyl, by reacting the precursor with novel cyclase, epimerase and ring expansion enzymes isolated from a cell-free extract of a prokaryotic organism such as Streptomyces clavuligerus. The three novel enzymes may be immobilized separately or together on a suitable support medium and the conversion may be carried out in a continuous mode.
摘要:
Verfahren zur Gewinnung von Cephalosporin C, seiner Salze und Derivate aus Kulturfiltraten oder -lösungen, das darin besteht, daß man das Kulturfiltrat oder die Kulturlösung trocknet, in einem gegebenenfalls wasserhaltigen, von Wasser verschiedenen Lösungsmittel aufnimmt, und a) ein Derivat oer Aminogruppe des Cephalosporin C bildet und dieses als freie Säure oder Salz isoliert oder b) das Cephalosporin C direkt oder als schwerlösliches Salz ausfällt.
摘要:
The present invention relates to the hemi sulfuric acid salt of D-phenylglycine methyl ester, to a method for the preparation of said salt and to the use of said salt in the enzymatic synthesis of antibiotics and of D-phenylglycine methyl ester free base.