Semisynthetic Beta-lactam Antibiotics Research Articles

Methodological Approach to Development of Enzymatic Technologies for Semisynthetic Betalactam Antibiotic Production

The algorithm for the research and design of optimized processes for synthesis of semisynthetic betalactam antibiotics with the use of peptidases with mechanism of action based on the acylenzyme interm ediate formation as a catalyst was formulated. The applicability of the proposed approach to the development of the processes for enzymatic synthesis of cefoxitin and cefazolin, semisynthetic cephalosporins, as an example, was demonstrated.

Determination of aspoxicillin (TA-058) by high-performance liquid chromatography. Stability at different temperatures

A rapid and sensitive HPLC-method has been developed for the determination of serum concentrations of aspoxicillin (TA-058), a new semisynthetic beta-lactam antibiotic. Aspoxicillin was chromatographed with a phosphate buffer/methanol (92:8 v/v) mobile phase and a C-18 reversed phase column and was detected at a wavelength of 220 nm. The stability of aspoxicillin in serum and buffer at different temperatures was studied over a time period of 3 months. Furthermore, the degradation of aspoxicillin versus piperacillin was determined in serum and buffer at 37 degrees C. Aspoxicillin remains stable only at -70 degrees C whereas degradation has been observed at -20 degrees C and 4 degrees C. At 37 degrees C, 20% of aspoxicillin is degraded in serum within 24 h whereas piperacillin is completely degraded under the same conditions.

Two-dimensional thin-layer chromatography for simultaneous detection of bacterial beta-lactam acylases and beta-lactamases.

A rapid and specific procedure was developed for the simultaneous detection of bacterial acylases and beta-lactamases, using ampicillin and cephalexin as substrates. Bacterial suspensions from agar plates were incubated separately with each beta-lactam substrate for 1 h at 37 degrees C. The supernatant of the reaction mixture was dansylated, and the dansyl derivatives were separated by two-dimensional thin-layer chromatography on polyamide sheets. The end products resulting from acylase hydrolysis, including the intact beta-lactam nucleus, 6-aminopenicillanic acid or 7-aminodeacetoxycephalosporanic acid, and the acyl side chain acid, D-(-)-alpha-aminophenylacetic acid, and the end product resulting from beta-lactamase hydrolysis (D-phenylglycylpenicilloic acid or D-phenylglycyldeacetoxycephalosporoic acid) were separated from each unhydrolyzed substrate and amino acids by this procedure. The presence of the intact beta-lactam nucleus in the reaction mixture is the indication of acylase activity. This method is sensitive and reproducible and has been successfully applied to screening for acylase activity in a variety of bacteria. It may be pharmaceutically useful for identifying organisms capable of removing the acyl side chain from naturally occurring beta-lactam antibiotics such as penicillin G, penicillin V, and cephalosporin C for production of the beta-lactam nuclei which serve as the starting materials for semisynthetic beta-lactam antibiotics.

Enzymatic synthesis of phenoxymethylpenicillin using Erwinia aroideae enzyme.

Enzymatic synthesis of phenoxymethylpenicillin from 6-aminopenicillanic acid and phenoxyacetic acid methyl ester was attempted by using partially purified alpha-acylamino-beta-lactam acylhydrolase I (ALAHase I) enzyme from Erwinia aroideae NRRL B-138. The reaction rates were carefully followed by determination of 6-aminopenicillanic acid (6-APA), phenoxymethylpenicillin (PNV), phenoxyacetic acid (POA), phenoxyacetic acid methyl ester (POM), and phenoxyacetylglycine (POG) using high performance liquid chromatography. Among the acyl donors tested, POM gave the highest yield (12.2% based on 6-APA). The overall conversion increased almost linearly with an increase in molar ratio of POM to 6-APA up to 4:1. The effects of organic solvents on the overall yield were also evaluated. Some improvement of PNV yield was observed when ethanol, 2-propanol, and acetone were used. ALAHase I was found to carry out three reactions simultaneously: transfer of acyl group to acyl acceptor to form semisynthetic beta-lactam antibiotic; hydrolysis of acyl donor in amide or ester bond, and hydrolysis of semisynthetic beta-lactam antibiotic which was produced by the enzyme. It was also observed that the hydrolysis reactions of POM and PNV were irreversible in this reaction system. The optimal pH for the three reactions was different. They were: pH 9.0 for POM hydrolysis, 6.8 for the transfer of phenoxyacetyl group to 6-APA, and 6.0 for the PNV hydrolysis. The apparent Km values for POM, 6-APA and PNV were estimated as 33, 25 and 31 mM, respectively.

BRL 17421, a novel beta-lactam antibiotic, highly resistant to beta-lactamases, giving high and prolonged serum levels in humans.

BRL 17421 is a new semisynthetic beta-lactam antibiotic with an unusual spectrum of antibacterial activity. The compound exhibits exceptional stability to a wide range of bacterial beta-lactamases and is active against the majority of Enterobacteriaceae, including strains highly resistant to many of the penicillins and cephalosporins currently available. Among the clinical isolates of Enterobacteriaceae tested, the frequency of strains resistant to BRL 17421 was found to be low, and there was a slow rate of emergence of resistance during in vitro studies. BRL 17421 was highly active against Haemophilus influenzae and Neisseria gonorrhoeae, including beta-lactamase-producing strains. The compound was markedly less active against Pseudomonas aeruginosa and Bacteroides fragilis than against the Enterobacteriaceae. Against the gram-positive bacteria, BRL 17421 showed a very low level of activity. BRL 17421 was found to be 85% bound to human serum, and the antibacterial activity was diminished two- to fourfold in the presence of human serum. Against experimental infections in mice, the activity of BRL 17421 reflected the properties observed in vitro. Studies in human volunteers showed unusually high and prolonged serum concentrations of the compound after parenteral dosage, with a serum half-life of about 5 h, and approximately 85% of the dose was recovered unchanged in the urine. BRL 17421 was poorly absorbed after oral administration. The compound was well tolerated after intramuscular and intravenous administration in volunteers, with no adverse side effects.

Purification and properties of cephalosporinase from Pseudomonas aeruginosa.

Cephalosporin beat-lactamase (cephalosporinase, CSase) was purified from a strain of Pseudomonas aeruginosa resistant to beta-lactam antibiotics. The purified enzyme preparation gave a single protein band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and its molecular weight was about 34,000. The specific activity was 49.7 mumoles/minute/mg of protein of the purified enzyme for the hydrolysis of cephaloridine. The optimal pH and optimal temperature were about 8.0 and 40 degrees C, respectively. Its isoelectric point was 8.7. The enzyme activity was inhibited by iodine, some divalent ions, and some semisynthetic beta-lactam antibiotics, including cephamycin derivatives such as moxalactam and YM09330. Mouse antiserum obtained against the purified enzyme showed no cross-reaction with other types of beta-lactamase in neutralization test.

Semisynthetic beta-lactam antibiotics. 6. 1 Sulfocephalosporins and their antipseudomonal activities.

Semisynthetic beta-lactam antibiotics. 6. 1 Sulfocephalosporins and their antipseudomonal activities.

ChemInform Abstract: SEMISYNTHETIC BETA‐LACTAM ANTIBIOTICS PART 7, NEW SEMISYNTHETIC CEPHALOSPORINS DERIVED FROM ALPHA‐SULFOPHENYLACETIC ACID

Chemischer InformationsdienstVolume 5, Issue 37 Natural Products ChemInform Abstract: SEMISYNTHETIC BETA-LACTAM ANTIBIOTICS PART 7, NEW SEMISYNTHETIC CEPHALOSPORINS DERIVED FROM ALPHA-SULFOPHENYLACETIC ACID H. NOMURA, H. NOMURASearch for more papers by this authorT. FUGONO, T. FUGONOSearch for more papers by this authorT. HITAKA, T. HITAKASearch for more papers by this authorI. MINAMI, I. MINAMISearch for more papers by this authorT. AZUMA, T. AZUMASearch for more papers by this authorS. MORIMOTO, S. MORIMOTOSearch for more papers by this authorT. MASUDA, T. MASUDASearch for more papers by this author H. NOMURA, H. NOMURASearch for more papers by this authorT. FUGONO, T. FUGONOSearch for more papers by this authorT. HITAKA, T. HITAKASearch for more papers by this authorI. MINAMI, I. MINAMISearch for more papers by this authorT. AZUMA, T. AZUMASearch for more papers by this authorS. MORIMOTO, S. MORIMOTOSearch for more papers by this authorT. MASUDA, T. MASUDASearch for more papers by this author First published: September 17, 1974 https://doi.org/10.1002/chin.197437433Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume5, Issue37September 17, 1974 RelatedInformation