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Antiseptics, antibiotics and chemotherapy
Published in Michael J. O’Dowd, The History of Medications for Women, 2020
Guiseppe Brotzu, of the University of Caligari, hypothesized in the mid–1940s that the apparent periodic clearance of microorganisms from the vicinity of a sewage outlet at Caligari was due to the inhibitory effects of substances produced by the fungus Cephalosporium acremonium chrysogenum. The substance was identified as cephalosporin C by researchers in Oxford. And so the family of cephalosporins was born. Modified cephalosporins included cephalexin, cephradine, cefaclor, Cefadroxil, and others.
High-Performance Liquid Chromatography
Published in Adorjan Aszalos, Modern Analysis of Antibiotics, 2020
Joel J. Kirschbaum, Adorjan Aszalos
An octadecylsilane column was used with a mobile phase of 0.1 M acetate buffer, pH 4.66-methanol (78:22) flowing at 0.8 ml/min into a detector set to 206 nm. Cephacetrile, cefuroxime, cephalexin, cephaloridine, cephradine, and cephalothin [152] were resolved. The separation of cephacetrile, cephalexin, cefazolin, cephradine, cephaloglycin, and cephalothin is shown in Figure 6. A 5-µm octylsilane column (150×4.6 mm) was used with a mobile phase of methanol-0.01 M sodium dihydrogen phosphate flowing at 1 ml/min through a detector at 254 nm [4]. The same type of column was used with 0.01 M tetrabutylammonium hydroxide (adjusted to pH 7.4 with H3PO4)-methanol (90:10) flowing at 1.1 ml/min through a 254 nm detector to monitor cephalosporin starting materials, which are often poorly resolved without an ion-pairing agent. Desacetylcephalosporin C, cephalosporin C, desacetoxycephalosporin C, 7-ADCA, and 7-ACA were resolved.
Human hyalohyphomycoses: A review of human infections due to Acremonium spp., Paecilomyces spp., Penicillium spp., Talaromyces spp., and Scopulariopsis spp.
Published in Mahmoud A. Ghannoum, John R. Perfect, Antifungal Therapy, 2019
The genus Acremonium, formerly known as Cephalosporium, contains about 100 different species that are ubiquitous in the environment and typically isolated in soil, insects, sewage, plants, and other environmental substrates [3]. The first recorded isolation of this species was Acremonium cephalosporium in 1939 [4]. In 1945, A. cephalosporium was isolated in the sewage effluent during a search for antibiotic-producing organisms of the coast of Sardinia [4]. By 1953, the active antimicrobial compound cephalosporin C was isolated from A. cephalosporium by investigators at Oxford University, United Kingdom, leading to the development of the cephalosporin class of antibiotics [4].
Classification for β-lactamases: historical perspectives
Published in Expert Review of Anti-infective Therapy, 2023
Naming of β-lactamases has been a challenging and sometimes confusing task, with researchers utilizing either functional characteristics or molecular properties to categorize these enzymes (Table 1). The historical expansion of functional names is demonstrated in Figure 1, where the initial appearance of currently accepted nomenclature is correlated with the development of the β-lactam antibiotics. The first β-lactamases were named penicillinases by Abraham and Chain [4], due to their ability to destroy the antibacterial properties of the potentially useful therapeutic agent known as penicillin. At that time, the structure of penicillin was unknown, and no other β-lactam structure had been identified. Thus, the name penicillinase was used for more than two decades to designate any enzyme that inactivated penicillin. Chemical studies established that the enzymes that hydrolyzed the β-lactam ring were readily differentiated from acylases (or amidases) that hydrolyzed the N-acyl side chain substituted on the β-lactam [33]. Following the identification of the naturally-occurring cephalosporins whose structures were shown to be related to penicillins, various ‘penicillinases’ identified from multiple sources were shown to destroy these new cephalosporins preferentially to penicillins. Thus, the name ‘cephalosporinase’ arose, based initially on the observed degradation of cephalosporin C by a strain of Enterobacter cloacae in 1963 [13]. Separation of penicillinases from cephalosporinases was not a trivial task, as the convention had been to name both the penicillin-hydrolyzing and cephalosporin-hydrolyzing enzymes as penicillinases. The first genetic map to identify the chromosomal ampC gene in E. coli K-12 in 1973 was associated with the ‘ampC penicillinase’ [34], which is now viewed as the prototypical AmpC cephalosporinase [35].
The war against bacteria, from the past to present and beyond
Published in Expert Review of Anti-infective Therapy, 2022
Lucrezia Bottalico, Ioannis Alexandros Charitos, Maria Assunta Potenza, Monica Montagnani, Luigi Santacroce
Mechanism of action – They are related to penicillins and classified in a common category under the term β-lactams, since they have a similar structure and, mode of action to penicillins. Cephalosporins are semi-synthetic antimicrobial drugs, derivatives of cephalosporin C, a substance found in Cephalosporium acremonium.
Synthesis, biological activities and docking studies of pleuromutilin derivatives with piperazinyl urea linkage
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2021
Yuanyuan Zhang, Chuan Xie, Yang Liu, Feng Shang, Rushiya Shao, Jing Yu, Chunxia Wu, Xinghui Yao, Dongfang Liu, Zhouyu Wang
Natural products such as Penicillin, Erythromycin, Cephalosporin C and Kanamycin are often used as main compounds in drug discoveries due to their potent bioactivity. Corresponding semi-synthesised derivatives Amoxicillin, Azithromycin, Cefpirome and Amikacin all exhibit higher potency than natural products5–7. Pleuromutilin (Figure 1, 1), a diterpenoid natural product from the basidiomycete species, shows moderate activities against Gram-positive strains and mycoplasmas8,9. Four semi-synthesised marketed drugs based on its structure have already been developed. Tiamulin and valnemulin (Figure 1, 2 and 3) can effectively prevent and control swine dysentery, mycoplasmal diseases such as enzootic pneumonia and chronic respiratory disease in poultry10,11. Retapamulin (Figure 1, 4) is used for the treatment of skin impetigo12,13. Lefamulin (Figure 1, 5) is approved for treatment of community-acquired bacterial pneumonia (CABP)14. These derivatives can inhibit bacterial protein synthesis via specific interaction with 23S rRNA of the 50S bacterial ribosome unit15, which are unaffected by resistance to major antibiotic classes, such as beta-lactam antibiotics, tetracyclines, macrolides, fluoroquinolones, and others. Thus, pleuromutilin is a promising candidate for treating drug-resistant bacteria infections16, and many compounds derived from four marketed drugs using the thioether as the linkage at the C14 side chain were developed in recent years17–20. To increase side chain diversity and improve modification success rate, the bioactive moiety piperazinyl urea, displaying multiple biological activities such as antifungal21, analgesic22, antibacterial23 and antitumour24 effects was introduced. In this study, a series of pleuromutilin derivatives 6a∼z with piperazinyl urea (Scheme 1) were efficiently synthesised. Their activities were evaluated against MRSA and Gram-negative strains, and interactions were examined by molecular docking.