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Antibacterial Drugs (antibacterial + drug)
Selected AbstractsChemInform Abstract: A New Practical Synthesis of Linezolid: An Antibacterial Drug.CHEMINFORM, Issue 27 2010Ganta Madhusudhan Reddy Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Photochemistry of Oxazolidinone Antibacterial Drugs,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2009Elisa Fasani The photochemistry of six N3-(3-fluoro-4-dialkylaminophenyl)-oxazolidinones known for their antimicrobial activity has been examined. All of these compounds are defluorinated in water (,dec , 0.25) and in methanol (,dec , 0.03), reasonably via the triplet. The chemical processes observed are reductive defluorination and solvolysis, depending on the structural variation introduced (thus, tethering the dialkylamino group to the aromatic ring and introducing a highly polar group in the oxazolidinone moiety have an effect). A likely mechanism involves the fragmentation of the C,F bond yielding the corresponding triplet phenyl cation. This intermediate either is reduced or, under appropriate conditions, intersystem crosses to the singlet state that adds the solvent. These data demonstrate a sizeable photodecomposition of these drugs that causes a decrease in the therapeutic activity. Furthermore, the likely formation of phenyl cations may cause a photogenotoxic effect. [source] Photosensitized DNA Damage: The Case of Fluoroquinolones,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2009Virginie Lhiaubet-Vallet This review focuses on DNA damage photosensitized by the fluoroquinolone (FQ) antibacterial drugs. The in vivo evidence for photocarcinogenesis mediated by FQs is presented in the introduction. The different methods employed for detection of DNA-photodamage mediated by FQs are then summarized, including gel electrophoresis (with whole cells, with isolated DNA and with oligonucleotides) and chromatographic analysis (especially HPLC with electrochemical and MS/MS detection). The chemical mechanisms involved in the formation of the reported lesions are discussed on the basis of product studies and transient spectroscopic evidence. In general, the literature coverage is limited to the last decade, although some earlier citations are also included. [source] Synthesis and antibacterial properties of peptidyl derivatives and cyclopeptides structurally based upon the inhibitory centre of human cystatin C: Dissociation of antiproteolytic and antibacterial effectsAPMIS, Issue 7-8 2000FRANCISZEK Kasprzykowski Cysteine protease-inhibiting proteins of the cystatin superfamily can inhibit the replication of certain viruses and bacteria. The inhibitory centre of human cystatin C, the most widely distributed human cystatin, comprises three peptide segments. The present work describes the synthesis and antibacterial activity of 27 new peptidyl derivatives or cyclopeptides based upon the aminoterminal segment Arg8 -Leu9 -Val10 -Gly11. Fourteen of the new compounds displayed antibacterial activity against from 1 up to 9 of 17 clinically important bacterial species tested. Antiproteolytic activity of a compound was usually not required for its antibacterial capacity. Peptidyl diazomethanes generally had a very narrow antibacterial spectrum, inhibiting only Streptococcus pyogenes, whereas cyclopeptides and peptidyl derivatives of the general structure X-Arg-Leu-NH-CH(iPr)-CH2 -NH-Y had a much wider spectrum. The most potent of these substances displayed approximately equal minimal inhibitory and bactericidal concentrations of about 20 ,g/ml for both Staphylococcus aureus and S. pyogenes and were devoid of antiproteolytic activity. Several of the new substances could protect mice against lethal intraperitoneal challenge with S. pyogenes. Though their target remains to be disclosed, the group of substances here reported might be promising for the development of antibacterial drugs and the discovery of novel principles of action. [source] DNA topology and topoisomerasesBIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION, Issue 1 2009Teaching a "knotty" subject Abstract DNA is essentially an extremely long double-stranded rope in which the two strands are wound about one another. As a result, topological properties of the genetic material, including DNA underwinding and overwinding, knotting, and tangling profoundly influence virtually every major nucleic acid process. Despite the importance of DNA topology, it is a conceptionally difficult subject to teach because it requires students to visualize three-dimensional relationships. This article will familiarize the reader with the concept of DNA topology and offer practical approaches and demonstrations to teaching this "knotty" subject in the classroom. Furthermore, it will discuss topoisomerases, the enzymes that regulate the topological state of DNA in the cell. These ubiquitous enzymes perform a number of critical cellular functions by generating transient breaks in the double helix. During this catalytic event, topoisomerases maintain genomic stability by forming covalent phosphotyrosyl bonds between active site residues and the newly generated DNA termini. Topoisomerases are essential for cell survival. However, because they cleave the genetic material, these enzymes also have the potential to fragment the genome. This latter feature of topoisomerases is exploited by some of the most widely prescribed anticancer and antibacterial drugs currently in clinical use. Finally, in addition to curing cancer, topoisomerase action also has been linked to the induction of specific types of leukemia. [source] Cloning, expression, crystallization and preliminary X-ray crystallographic analysis of leucine aminopeptidase (LAP) from the pepA gene of Xanthomonas oryzae pv. oryzaeACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 9 2009Kim-Hung Huynh Xanthomonas oryzae pv. oryzae (Xoo) causes the serious disease bacterial blight in rice. The pepA (Xoo0834) gene from Xoo is one of around 100 genes that have been selected for the design of antibacterial drugs. The pepA gene encodes leucine aminopeptidase (LAP), an exopeptidase that catalyzes the hydrolysis of leucine residues from the N-terminus of a protein or peptide. This enzyme was expressed in Escherichia coli, purified and crystallized, and preliminary X-ray structural studies have been carried out. The LAP crystal diffracted to 2.6,Å resolution and belonged to the cubic space group P213. The unit-cell volume of the crystal was compatible with the presence of two monomers in the asymmetric unit. [source] Cloning, expression, crystallization and preliminary X-ray crystallographic analysis of ,-ketoacyl-ACP synthase III (FabH) from Xanthomonas oryzae pv. oryzaeACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 5 2009Kim-Hung Huynh The bacterial ,-ketoacyl-ACP synthase III (KASIII) encoded by the gene fabH (Xoo4209) from Xanthomonas oryzae pv. oryzae, a plant pathogen, is an important enzyme in the elongation steps of fatty-acid biosynthesis. It is expected to be one of the enzymes responsible for bacterial blight (BB), a serious disease that results in huge production losses of rice. As it represents an important target for the development of new antibacterial drugs against BB, determination of the crystal structure of the KAS III enzyme is essential in order to understand its reaction mechanism. In order to analyze the structure and function of KAS III, the fabH (Xoo4209) gene was cloned and the enzyme was expressed and purified. The KASIII crystal diffracted to 2.05,Å resolution and belonged to the orthorhombic space group P21212, with unit-cell parameters a = 69.8, b = 79.5, c = 62.3,Å. The unit-cell volume of the crystal is compatible with the presence of a single monomer in the asymmetric unit, with a corresponding Matthews coefficient VM of 2.27,Å3,Da,1 and a solvent content of 45.8%. [source] Cloning, expression, crystallization and preliminary X-ray crystallographic analysis of glutamyl-tRNA synthetase (Xoo1504) from Xanthomonas oryzae pv. oryzaeACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 1 2009Thanh Thi Ngoc Doan The gltX gene from Xanthomonas oryzae pv. oryzae (Xoo1504) encodes glutamyl-tRNA synthetase (GluRS), one of the most important enzymes involved in bacterial blight (BB), which causes huge production losses of rice worldwide. GluRS is a class I-type aminoacyl-tRNA synthetase (aaRS) that is primarily responsible for the glutamylation of tRNAGlu. It plays an essential role in protein synthesis, as well as the regulation of cells, in all organisms. As it represents an important target for the development of new antibacterial drugs against BB, determination of the three-dimensional structure of GluRS is essential in order to understand its catalytic mechanism. In order to analyze its structure and function, the gltX gene was cloned and the GluRS enzyme was expressed, purified and then crystallized. A GluRS crystal belonging to the monoclinic space group C2 diffracted to 2.8,Å resolution and had unit-cell parameters a = 186.8, b = 108.4, c = 166.1,Å, , = 96.3°. The unit-cell volume of the crystal allowed the presence of six to eight monomers in the asymmetric unit, with a corresponding Matthews coefficient (VM) range of 2.70,2.02,Å3,Da,1 and a solvent-content range of 54.5,39.3%. [source] | ||||||||||