51
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Aoki H, Xu J, Emili A, Chosay JG, Golshani A, Ganoza MC. Interactions of elongation factor EF-P with the Escherichia coli ribosome. FEBS J 2008; 275:671-81. [PMID: 18201202 DOI: 10.1111/j.1742-4658.2007.06228.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
EF-P (eubacterial elongation factor P) is a highly conserved protein essential for protein synthesis. We report that EF-P protects 16S rRNA near the G526 streptomycin and the S12 and mRNA binding sites (30S T-site). EF-P also protects domain V of the 23S rRNA proximal to the A-site (50S T-site) and more strongly the A-site of 70S ribosomes. We suggest that EF-P: (a) may play a role in translational fidelity and (b) prevents entry of fMet-tRNA into the A-site enabling it to bind to the 50S P-site. We also report that EF-P promotes a ribosome-dependent accommodation of fMet-tRNA into the 70S P-site.
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52
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Synthesis and antibacterial activity of potent heterocyclic oxazolidinones and the identification of RBx 8700. Bioorg Med Chem Lett 2007; 17:6714-9. [PMID: 17980588 DOI: 10.1016/j.bmcl.2007.10.061] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2007] [Revised: 10/16/2007] [Accepted: 10/16/2007] [Indexed: 11/22/2022]
Abstract
Several potent oxazolidinone antibacterial agents were obtained by systematic modification of the linker between the five-membered heterocycle and the piperazinyl ring of RBx 7644 (Ranbezolid, 1) and its thienyl analogue 2, leading to the identification of an expanded spectrum compound RBx 8700 (6b).
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53
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Reck F, Zhou F, Eyermann CJ, Kern G, Carcanague D, Ioannidis G, Illingworth R, Poon G, Gravestock MB. Novel Substituted (Pyridin-3-yl)phenyloxazolidinones: Antibacterial Agents with Reduced Activity against Monoamine Oxidase A and Increased Solubility. J Med Chem 2007; 50:4868-81. [PMID: 17722903 DOI: 10.1021/jm070428+] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Oxazolidinones represent a new and promising class of antibacterial agents. Current research in this area is mainly concentrated on improving the safety profile and the antibacterial spectrum. Oxazolidinones bearing a (pyridin-3-yl)phenyl moiety (e.g., 3) generally show improved antibacterial activity compared to linezolid but suffer from potent monoamine oxidase A (MAO-A) inhibition and low solubility. We now disclose the finding that new analogues of 3 with acyclic substituents on the pyridyl moiety exhibit excellent activity against Gram-positive pathogens, including linezolid-resistant Streptococcus pneumoniae. Generally, more bulky substituents yielded significantly reduced MAO-A inhibition relative to the unsubstituted compound 3. The MAO-A SAR can be rationalized on the basis of docking studies using a MAO-A/MAO-B homology model. Solubility was enhanced with incorporation of polar groups. One optimized analogue, compound 13, showed low clearance in the rat and efficacy against S. pneumoniae in a mouse pneumonia model.
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Affiliation(s)
- Folkert Reck
- AstraZeneca Discovery, AstraZeneca R&D Boston, 35 Gatehouse Drive, Waltham, Massachusetts 02451, USA.
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54
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Fan H, Chen Y, Jiang Z, Zhang S, Zhong D, Ji R, Yang Y. Synthesis and biological evaluation of new N-linked 5-triazolylmethyl oxazolidinones. Eur J Med Chem 2007; 43:1706-14. [PMID: 17981369 DOI: 10.1016/j.ejmech.2007.09.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2007] [Revised: 09/07/2007] [Accepted: 09/13/2007] [Indexed: 11/17/2022]
Abstract
A new series of oxazolidinones bearing N-linked 5-triazolylmethyl group have been synthesized and their in vitro antibacterial activities (MIC) were evaluated against a spectrum of resistant and susceptible Gram-positive organisms. Some of the analogues in this series displayed activity superior to linezolid and vancomycin. Furthermore, in vivo efficacies and pharmacokinetic properties of the selected compounds were also disclosed herein; the selected compounds showed reasonable bioavailability as well as in vivo efficacy comparable to that of linezolid.
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Affiliation(s)
- Houxing Fan
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai 201203, China
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55
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Rudra S, Sangita F, Gujrati A, Pandya M, Bhateja P, Mathur T, Singhal S, Rattan A, Salman M, Das B. Synthesis and antibacterial activity of novel oxazolidinones with methylene oxygen- and methylene sulfur-linked substituents at C5-position. Bioorg Med Chem Lett 2007; 17:4778-83. [PMID: 17618116 DOI: 10.1016/j.bmcl.2007.06.056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2007] [Revised: 05/28/2007] [Accepted: 06/20/2007] [Indexed: 11/22/2022]
Abstract
Novel oxazolidinone derivatives of the lead compound RBx 8700, containing methylene oxygen- and methylene sulfur-linked substituents at the C5-position, were synthesized. Antibacterial screening of these compounds against a panel of resistant and susceptible Gram-positive and fastidious Gram-negative bacteria gave compounds 2 and 4 as new antibacterial agents.
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Affiliation(s)
- Sonali Rudra
- Department of Medicinal Chemistry, New Drug Discovery Research, Ranbaxy Laboratories Limited, Plot-20, Sector-18, Udyog Vihar, Gurgaon, India.
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56
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Leach KL, Swaney SM, Colca JR, McDonald WG, Blinn JR, Thomasco LM, Gadwood RC, Shinabarger D, Xiong L, Mankin AS. The site of action of oxazolidinone antibiotics in living bacteria and in human mitochondria. Mol Cell 2007; 26:393-402. [PMID: 17499045 DOI: 10.1016/j.molcel.2007.04.005] [Citation(s) in RCA: 201] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2007] [Revised: 04/02/2007] [Accepted: 04/05/2007] [Indexed: 11/30/2022]
Abstract
The oxazolidinones are one of the newest classes of antibiotics. They inhibit bacterial growth by interfering with protein synthesis. The mechanism of oxazolidinone action and the precise location of the drug binding site in the ribosome are unknown. We used a panel of photoreactive derivatives to identify the site of action of oxazolidinones in the ribosomes of bacterial and human cells. The in vivo crosslinking data were used to model the position of the oxazolidinone molecule within its binding site in the peptidyl transferase center (PTC). Oxazolidinones interact with the A site of the bacterial ribosome where they should interfere with the placement of the aminoacyl-tRNA. In human cells, oxazolidinones were crosslinked to rRNA in the PTC of mitochondrial, but not cytoplasmic, ribosomes. Interaction of oxazolidinones with the mitochondrial ribosomes provides a structural basis for the inhibition of mitochondrial protein synthesis, which is linked to clinical side effects associated with oxazolidinone therapy.
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MESH Headings
- Acetamides
- Anti-Infective Agents/chemistry
- Anti-Infective Agents/pharmacology
- Binding Sites/drug effects
- Cross-Linking Reagents/chemistry
- Cross-Linking Reagents/pharmacology
- Cytoplasm/drug effects
- Cytoplasm/enzymology
- Drug Resistance/genetics
- Escherichia coli/drug effects
- Escherichia coli/enzymology
- Humans
- Linezolid
- Mitochondria/drug effects
- Mitochondria/enzymology
- Models, Molecular
- Molecular Structure
- Mutation/genetics
- Oxazolidinones/chemistry
- Oxazolidinones/pharmacology
- Peptidyl Transferases/drug effects
- Peptidyl Transferases/metabolism
- Protein Synthesis Inhibitors/chemistry
- Protein Synthesis Inhibitors/pharmacology
- RNA, Bacterial/genetics
- RNA, Bacterial/metabolism
- RNA, Ribosomal/drug effects
- RNA, Ribosomal/metabolism
- RNA, Ribosomal, 23S
- RNA, Transfer, Amino Acyl/antagonists & inhibitors
- RNA, Transfer, Amino Acyl/metabolism
- Software
- Staining and Labeling
- Staphylococcus aureus/drug effects
- Staphylococcus aureus/enzymology
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Affiliation(s)
- Karen L Leach
- Pfizer Inc., 2800 Plymouth Road, Ann Arbor, MI 48105, USA
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57
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Fan H, Xu G, Chen Y, Jiang Z, Zhang S, Yang Y, Ji R. Synthesis and antibacterial activity of oxazolidinones containing triazolyl group. Eur J Med Chem 2007; 42:1137-43. [PMID: 17363116 DOI: 10.1016/j.ejmech.2007.01.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2006] [Revised: 01/03/2007] [Accepted: 01/08/2007] [Indexed: 11/22/2022]
Abstract
A new series of oxazolidinones containing triazolyl group has been synthesized and tested for in vitro antibacterial activity by MIC determination against a panel of resistant and susceptible Gram-positive organisms. Most of the analogs in this series displayed activity superior to linezolid and vancomycin in vitro. Further, in vivo efficacies of the selected oxazolidinones were also disclosed herein.
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Affiliation(s)
- Houxing Fan
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai 201203, China
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58
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Janin YL. Antituberculosis drugs: ten years of research. Bioorg Med Chem 2007; 15:2479-513. [PMID: 17291770 DOI: 10.1016/j.bmc.2007.01.030] [Citation(s) in RCA: 360] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2006] [Revised: 12/26/2006] [Accepted: 01/17/2007] [Indexed: 02/03/2023]
Abstract
Tuberculosis is today amongst the worldwide health threats. As resistant strains of Mycobacterium tuberculosis have slowly emerged, treatment failure is too often a fact, especially in countries lacking the necessary health care organisation to provide the long and costly treatment adapted to patients. Because of lack of treatment or lack of adapted treatment, at least two million people will die of tuberculosis this year. Due to this concern, this infectious disease was the focus of renewed scientific interest in the last decade. Regimens were optimized and much was learnt on the mechanisms of action of the antituberculosis drugs used. Moreover, the quest for original drugs overcoming some of the problems of current regimens also became the focus of research programmes and many new series of M. tuberculosis growth inhibitors were reported. This review presents the drugs currently used in antituberculosis treatments and the most advanced compounds undergoing clinical trials. We then provide a description of their mechanism of action along with other series of inhibitors known to act on related biochemical targets. This is followed by other inhibitors of M. tuberculosis growth, including recently reported compounds devoid of a reported mechanism of action.
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Affiliation(s)
- Yves L Janin
- URA 2128 CNRS-Institut Pasteur, 28 rue du Dr. Roux, 75724 Paris Cedex 15, France.
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59
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Zhang J, Chen HN, Chiang FI, Takemoto JY, Bensaci M, Chang CWT. Sonication-Assisted Library Synthesis of Oxazolidinone−Carbohydrate Conjugates. ACTA ACUST UNITED AC 2006; 9:17-9. [PMID: 17206828 DOI: 10.1021/cc060146f] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jianjun Zhang
- Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, Utah 84322-0300, USA
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60
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Narina SV, Sudalai A. Short and practical enantioselective synthesis of linezolid and eperezolid via proline-catalyzed asymmetric α-aminooxylation. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2006.07.065] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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61
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McKee EE, Ferguson M, Bentley AT, Marks TA. Inhibition of mammalian mitochondrial protein synthesis by oxazolidinones. Antimicrob Agents Chemother 2006; 50:2042-9. [PMID: 16723564 PMCID: PMC1479116 DOI: 10.1128/aac.01411-05] [Citation(s) in RCA: 187] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The effects of a variety of oxazolidinones, with different antibacterial potencies, including linezolid, on mitochondrial protein synthesis were determined in intact mitochondria isolated from rat heart and liver and rabbit heart and bone marrow. The results demonstrate that a general feature of the oxazolidinone class of antibiotics is the inhibition of mammalian mitochondrial protein synthesis. Inhibition was similar in mitochondria from all tissues studied. Further, oxazolidinones that were very potent as antibiotics were uniformly potent in inhibiting mitochondrial protein synthesis. These results were compared to the inhibitory profiles of other antibiotics that function by inhibiting bacterial protein synthesis. Of these, chloramphenicol and tetracycline were significant inhibitors of mammalian mitochondrial protein synthesis while the macrolides, lincosamides, and aminoglycosides were not. Development of future antibiotics from the oxazolidinone class will have to evaluate potential mitochondrial toxicity.
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Affiliation(s)
- E E McKee
- Indiana University School of Medicine--South Bend, IN 46617, USA.
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62
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Means J, Katz S, Nayek A, Anupam R, Hines JV, Bergmeier SC. Structure–activity studies of oxazolidinone analogs as RNA-binding agents. Bioorg Med Chem Lett 2006; 16:3600-4. [PMID: 16603349 DOI: 10.1016/j.bmcl.2006.03.068] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2006] [Revised: 03/20/2006] [Accepted: 03/21/2006] [Indexed: 11/26/2022]
Abstract
We have synthesized and tested a series of novel 3,4,5-tri- and 4,5-disubstituted oxazolidinones for their ability to bind two structurally related T box antiterminator model RNAs. We have found that optimal binding selectivity is found in a small group of 4,5-disubstituted oxazolidinones.
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Affiliation(s)
- John Means
- Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701, USA
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63
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Roberts SM, Freeman AF, Harrington SM, Holland SM, Murray PR, Zelazny AM. Linezolid-resistant Staphylococcus aureus in two pediatric patients receiving low-dose linezolid therapy. Pediatr Infect Dis J 2006; 25:562-4. [PMID: 16732160 DOI: 10.1097/01.inf.0000219401.70804.1a] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We report 2 sisters with hyper-IgE syndrome treated with daily suppressive dosages of linezolid (LZD) who developed LZD-resistant Staphylococcus aureus carrying the G2576T mutation in the 23S rRNA gene. Molecular typing suggested transmission of the resistant strain from one sister to the other. LZD-susceptible S. aureus was isolated 2 months after LZD discontinuation. LZD-resistant S. aureus remains rare but may occur while receiving suppressive therapy.
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Affiliation(s)
- Susanne M Roberts
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, MD 20892, USA
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64
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Jacqueline C, Caillon J, Potel G. Linézolide, données récentes expérimentales in vitro et in vivo. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/s1294-5501(05)80455-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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65
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Nagiec EE, Wu L, Swaney SM, Chosay JG, Ross DE, Brieland JK, Leach KL. Oxazolidinones inhibit cellular proliferation via inhibition of mitochondrial protein synthesis. Antimicrob Agents Chemother 2005; 49:3896-902. [PMID: 16127068 PMCID: PMC1195406 DOI: 10.1128/aac.49.9.3896-3902.2005] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The oxazolidinones are a relatively new structural class of antibacterial agents that act by inhibiting bacterial protein synthesis. The oxazolidinones inhibit mitochondrial protein synthesis, as shown by [35S]methionine incorporation into intact rat heart mitochondria. Treatment of K562 human erythroleukemia cells with the oxazolidinone eperezolid resulted in a time- and concentration-dependent inhibition of cell proliferation. The cells remained viable, but an increase in doubling time was observed with eperezolid treatment. Inhibition was reversible, since washing and refeeding of cells in the absence of compound resulted in a resumption of growth. The growth-inhibitory effect of the oxazolidinones did not appear to be cell type specific, and inhibition of CHO and HEK cells also was demonstrated. Treatment of cells resulted in a decrease in mitochondrial cytochrome oxidase subunit I levels, consistent with an inhibition of mitochondrial protein synthesis. Eperezolid caused no growth inhibition of rho zero (rho0) cells, which contain no mitochondrial DNA; however, the growth of the parent 143B cells was inhibited. These results provide a direct demonstration that the inhibitory effect of eperezolid in mammalian cells is the result of mitochondrial protein synthesis inhibition.
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Affiliation(s)
- Eva E Nagiec
- Department of Antibacterial Pharmacology, Pfizer, Ann Arbor, MI 48105, USA
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66
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Campbell T, Daigle D, Brown E. Characterization of the Bacillus subtilis GTPase YloQ and its role in ribosome function. Biochem J 2005; 389:843-52. [PMID: 15828870 PMCID: PMC1180735 DOI: 10.1042/bj20041873] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We present an analysis of the cellular phenotype and biochemical activity of a conserved bacterial GTPase of unknown function (YloQ and YjeQ in Bacillus subtilis and Escherichia coli respectively) using a collection of antibiotics of diverse mechanisms and chemical classes. We created a yloQ deletion strain, which exhibited a slow growth phenotype and formed chains of filamentous cells. Additionally, we constructed a conditional mutant in yloQ, where growth was dependent on inducible expression from a complementing copy of the gene. In phenotypic studies, depletion of yloQ sensitized cells to antibiotics that bind at the peptide channel or peptidyl transferase centre, providing the first chemical genetic evidence linking this GTPase to ribosome function. Additional experiments using these small-molecule probes in vitro revealed that aminoglycoside antibiotics severely affected a previously characterized ribosome-associated GTPase activity of purified, recombinant YjeQ from E. coli. None of the antibiotics tested competed with YjeQ for binding to 30 or 70 S ribosomes. A closer examination of YloQ depletion revealed that the polyribosome profiles were altered and that decreased expression of YloQ led to the accumulation of ribosomal subunits at the expense of intact 70 S ribosomes. The present study provides the first evidence showing that YloQ/YjeQ may be involved in several areas of cellular metabolism, including cell division and ribosome function.
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Affiliation(s)
- Tracey L. Campbell
- Department of Biochemistry and Biomedical Sciences, Antimicrobial Research Centre, McMaster University, 1200 Main Street West, Hamilton, ON, Canada L8N 3Z5
| | - Denis M. Daigle
- Department of Biochemistry and Biomedical Sciences, Antimicrobial Research Centre, McMaster University, 1200 Main Street West, Hamilton, ON, Canada L8N 3Z5
| | - Eric D. Brown
- Department of Biochemistry and Biomedical Sciences, Antimicrobial Research Centre, McMaster University, 1200 Main Street West, Hamilton, ON, Canada L8N 3Z5
- To whom correspondence should be addressed (email )
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67
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Griera R, Cantos-Llopart C, Amat M, Bosch J, del Castillo JC, Huguet J. New potential antibacterials: a synthetic route to N-aryloxazolidinone/3-aryltetrahydroisoquinoline hybrids. Bioorg Med Chem Lett 2005; 16:529-31. [PMID: 16275066 DOI: 10.1016/j.bmcl.2005.10.053] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2005] [Accepted: 10/18/2005] [Indexed: 11/28/2022]
Abstract
A synthetic route to a new structural type of potential antibacterials, with a hybrid 3-aryltetrahydroisoquinoline-6,7-diol/N-aryloxazolidinone structure, is reported. The synthesis involves the successive construction of the 3-aryltetrahydroisoquinoline and 4-substituted oxazolidinone moieties, the latter taking advantage of the functionalization at the para position of the aryl group.
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Affiliation(s)
- Rosa Griera
- Laboratory of Organic Chemistry, Faculty of Pharmacy, University of Barcelona, 08028 Barcelona, Spain
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68
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Das B, Rudra S, Yadav A, Ray A, Rao AVSR, Srinivas ASSV, Soni A, Saini S, Shukla S, Pandya M, Bhateja P, Malhotra S, Mathur T, Arora SK, Rattan A, Mehta A. Synthesis and SAR of novel oxazolidinones: Discovery of ranbezolid. Bioorg Med Chem Lett 2005; 15:4261-7. [PMID: 16054358 DOI: 10.1016/j.bmcl.2005.06.063] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2005] [Revised: 06/20/2005] [Accepted: 06/22/2005] [Indexed: 11/19/2022]
Abstract
Novel oxazolidinones were synthesized containing a number of substituted five-membered heterocycles attached to the 'piperazinyl-phenyl-oxazolidinone' core of eperezolid. Further, the piperazine ring of the core was replaced by other diamino-heterocycles. These modifications led to several compounds with potent activity against a spectrum of resistant and susceptible gram-positive organisms, along with the identification of ranbezolid (RBx 7644) as a clinical candidate.
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Affiliation(s)
- Biswajit Das
- Department of Medicinal Chemistry, Ranbaxy Research Laboratory, Plot-20, Sector-18, Udyog Vihar, Gurgaon 122001, India.
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69
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Carsenti-Dellamonica H, Galimand M, Vandenbos F, Pradier C, Roger PM, Dunais B, Sabah M, Mancini G, Dellamonica P. In vitro selection of mutants of Streptococcus pneumoniae resistant to macrolides and linezolid: relationship with susceptibility to penicillin G or macrolides. J Antimicrob Chemother 2005; 56:633-42. [PMID: 16135525 DOI: 10.1093/jac/dki301] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES To evaluate the rate of acquisition of resistance to linezolid and macrolides in Streptococcus pneumoniae isolates with different levels of susceptibility to penicillin and erythromycin. MATERIALS AND METHODS Thirty strains of S. pneumoniae were tested by serial passages in subinhibitory concentrations of each antibiotic by the spiral method. The four copies of the 23S rRNA rrl gene of parent strains and linezolid-resistant mutants were amplified and sequenced. RESULTS The rate of acquisition of macrolide resistance did not differ when C-14 and C-16 macrolides were tested. Resistance to linezolid in strains susceptible to penicillin and erythromycin was difficult to produce. For mutants with low-level resistance to linezolid the cut-off value of the MIC was between 6 and 8 mg/L depending on the strain. All linezolid-resistant mutants displayed a mutation in 2-4 copies of the 23S rRNA rrl gene, mainly the G2576U mutation (27/30) with an additional C2610U mutation observed in certain mutants. Two new mutations were also noted, namely C2612A and C2571G. In three linezolid-resistant mutants no mutation was identified within the studied domain, suggesting another mechanism of resistance. CONCLUSIONS Linezolid resistance in pneumococcal strains susceptible to penicillin and macrolides was more difficult to obtain than with macrolides. Increased resistance to these agents may therefore influence the clinical use of linezolid.
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Affiliation(s)
- H Carsenti-Dellamonica
- Infectious Disease Department, Archet Hospital, Route Saint Antoine de Ginestière, Nice 06202, France.
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70
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Griera R, Cantos-Llopart C, Amat M, Bosch J, del Castillo JC, Huguet J. A synthetic route to a novel type of conformationally constrained N-aryloxazolidinones. Bioorg Med Chem Lett 2005; 15:2515-7. [PMID: 15863307 DOI: 10.1016/j.bmcl.2005.03.071] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2004] [Revised: 03/17/2005] [Accepted: 03/17/2005] [Indexed: 12/01/2022]
Abstract
The synthesis of N-aryloxazolidinone 1, a conformationally constrained analog of linezolid embodying a tricyclic pyrrolo[1,2-a][4,1]benzoxazepine moiety as the N-aryl substituent, is reported. The synthetic route involves the successive construction of the pyrrole, oxazepine, and oxazolidinone rings, with incorporation of the isoxazolylamino moiety in the last synthetic steps.
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Affiliation(s)
- Rosa Griera
- Laboratory of Organic Chemistry, Faculty of Pharmacy, University of Barcelona, 0802-Barcelona, Spain
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71
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72
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Xu J, Golshani A, Aoki H, Remme J, Chosay J, Shinabarger DL, Ganoza MC. Protected nucleotide G2608 in 23S rRNA confers resistance to oxazolidinones in E. coli. Biochem Biophys Res Commun 2005; 328:471-6. [PMID: 15694371 DOI: 10.1016/j.bbrc.2004.12.189] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2004] [Indexed: 11/19/2022]
Abstract
The oxazolidinones are a new class of potent antibiotics that are active against a broad spectrum of Gram-positive bacterial pathogens including those resistant to other antibiotics. These drugs specifically inhibit protein biosynthesis whereas DNA and RNA synthesis are not affected. Although biochemical and genetic studies indicate that oxazolidinones target the ribosomal peptidyltransferase center, other investigations suggest that they interact with different regions of ribosomes. Thus, the exact binding site and mechanism of action have remained elusive. Here, we study, by use of base-specific reagents, the effect of the oxazolidinones on the chemical protection footprinting patterns of the 23S rRNA. We report: (i) reproducible protection of G2607 and G2608 of 23S rRNA by a potent oxazolidinone on a ribosome.tRNA.mRNA complex; (ii) no protections were observed on 70S ribosomes devoid of tRNA and mRNA; (iii) EF-G also weakly protected G2607 and G2608; (iv) mutations at G2608 conferred resistance to the oxazolidinones in Escherichia coli cells; and (v) G2607 and G2608 occur near the exit to the peptide tunnel on the 50S subunit. A mechanism for the pleiotropic action of the oxazolidinones is discussed.
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Affiliation(s)
- Jianhua Xu
- Banting and Best Department of Medical Research, University of Toronto, Ont., Canada M5G 1L6
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73
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Hancock RE. Mechanisms of action of newer antibiotics for Gram-positive pathogens. THE LANCET. INFECTIOUS DISEASES 2005; 5:209-18. [PMID: 15792738 DOI: 10.1016/s1473-3099(05)70051-7] [Citation(s) in RCA: 157] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Certain Gram-positive bacteria, including meticillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and quinolone-resistant Streptococcus pneumoniae have achieved the status of "superbugs", in that there are few or no antibiotics available for therapy against these pathogens. Only a few classes of novel antibiotics have been introduced in the past 40 years, and all since 1999, including the streptogramin combination quinupristin/dalfopristin (Synercid), the oxazolidinone linezolid, and the lipopeptide daptomycin. This review discusses the mechanisms of antibiotic action against Gram-positive pathogens, and resistance counter-mechanisms developed by Gram-positive bacteria, with emphasis on the newer agents.
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Affiliation(s)
- Robert Ew Hancock
- University of British Columbia, Vancouver, British Columbia, Canada.
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74
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Abelian A, Walsh A, Lentzen G, Aboul-Ela F, Gait M. Targeting the A site RNA of the Escherichia coli ribosomal 30 S subunit by 2'-O-methyl oligoribonucleotides: a quantitative equilibrium dialysis binding assay and differential effects of aminoglycoside antibiotics. Biochem J 2005; 383:201-8. [PMID: 15294017 PMCID: PMC1134060 DOI: 10.1042/bj20040246] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The bacterial ribosome comprises 30 S and 50 S ribonucleoprotein subunits, contains a number of binding sites for known antibiotics and is an attractive target for selection of novel antibacterial agents. On the 30 S subunit, for example, the A site (aminoacyl site) close to the 3'-end of 16 S rRNA is highly important in the decoding process. Binding by some aminoglycoside antibiotics to the A site leads to erroneous protein synthesis and is lethal for bacteria. We targeted the A site on purified 30 S ribosomal subunits from Escherichia coli with a set of overlapping, complementary OMe (2'-O-methyl) 10-mer oligoribonucleotides. An equilibrium dialysis technique was applied to measure dissociation constants of these oligonucleotides. We show that there is a single high-affinity region, spanning from A1493 to C1510 (Kd, 29-130 nM), flanked by two lower-affinity regions, within a span from U1485 to G1516 (Kd, 310-4300 nM). Unexpectedly, addition of the aminoglycoside antibiotic paromomycin (but not hygromycin B) caused a dose-dependent increase of up to 7.5-fold in the binding of the highest affinity 10-mer 1493 to 30 S subunits. Oligonucleotides containing residues complementary to A1492 and/or A1493 showed particularly marked stimulation of binding by paromomycin. The results are consistent with high-resolution structures of antibiotic binding to the A site and with greater accessibility of residues of A1492 and A1493 upon paromomycin binding. 10-mer 1493 binding is thus a probe of the conformational switch to the 'closed' conformation triggered by paromomycin that is implicated in the discrimination by 30 S subunits of cognate from non-cognate tRNA and the translational misreading caused by paromomycin. Finally, we show that OMe oligonucleotides targeted to the A site are moderately good inhibitors of in vitro translation and that there is a limited correlation of inhibition activity with binding strength to the A site.
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Affiliation(s)
- Arthur Abelian
- *Medical Research Council, Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, U.K
| | - Andrew P. Walsh
- *Medical Research Council, Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, U.K
| | - Georg Lentzen
- †Vernalis, Granta Park, Abington, Cambridge CB1 6GB, U.K
| | | | - Michael J. Gait
- *Medical Research Council, Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, U.K
- To whom correspondence should be addressed (email )
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75
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Reck F, Zhou F, Girardot M, Kern G, Eyermann CJ, Hales NJ, Ramsay RR, Gravestock MB. Identification of 4-substituted 1,2,3-triazoles as novel oxazolidinone antibacterial agents with reduced activity against monoamine oxidase A. J Med Chem 2005; 48:499-506. [PMID: 15658863 DOI: 10.1021/jm0400810] [Citation(s) in RCA: 245] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Oxazolidinones represent a new and promising class of antibacterial agents. Current research in this area is mainly concentrated on improving the safety profile and the antibacterial spectrum. Many oxazolidinones, including linezolid (marketed as Zyvox), are inhibitors of monoamine oxidase A (MAO-A), which presents an undesired side effect. Recently, it was found that the 1,2,3-triazole is a good replacement for the conventional acetamide functionality found in oxazolidinones. We now disclose the finding that 1,2,3-triazoles bearing a substituent like methyl, small substituted methyl, bromo, or a linear (sp-hybridized) group at the 4 position (compounds such as 5, 16, 19, and 21) are good antibacterials with reduced or no activity, within the detection limit of the assay, against MAO-A. The results are especially promising for the development of oxazolidinones with an improved safety profile. The MAO-A SAR can be rationalized on the basis of docking studies to a MAO-A/MAO-B homology model.
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Affiliation(s)
- Folkert Reck
- AstraZeneca Discovery, AstraZeneca R&D Boston, 35 Gatehouse Drive, Waltham, Massachusetts 02451, USA.
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76
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Jacqueline C, Navas D, Batard E, Miegeville AF, Le Mabecque V, Kergueris MF, Bugnon D, Potel G, Caillon J. In vitro and in vivo synergistic activities of linezolid combined with subinhibitory concentrations of imipenem against methicillin-resistant Staphylococcus aureus. Antimicrob Agents Chemother 2005; 49:45-51. [PMID: 15616274 PMCID: PMC538916 DOI: 10.1128/aac.49.1.45-51.2005] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Indifference or moderate antagonism of linezolid combined with other antibiotics in vitro and in vivo have mainly been reported in the literature. We have assessed the in vitro activities of linezolid, alone or in combination with imipenem, against methicillin-resistant Staphylococcus aureus (MRSA) strains using the dynamic checkerboard and time-kill curve methods. Linezolid and low concentrations of imipenem had a synergistic effect, leading us to evaluate the in vivo antibacterial activity of the combination using the rabbit endocarditis experimental model. Two MRSA strains were used for in vivo experiments: one was a heterogeneous glycopeptide-intermediate clinical S. aureus strain isolated from blood cultures, and the other was the S. aureus COL reference strain. Animals infected with one of two MRSA strains were randomly assigned to one of the following treatments: no treatment (controls), linezolid (simulating a dose in humans of 10 mg/kg of body weight every 12 h), a constant intravenous infusion of imipenem (which allowed the steady-state concentration of about 1/32 the MIC of imipenem for each strain to be reached in serum), or the combination of both treatments. Linezolid and imipenem as monotherapies exhibited no bactericidal activity against either strain. The combination of linezolid plus imipenem showed in vivo bactericidal activity that corresponded to a decrease of at least 4.5 log CFU/g of vegetation compared to the counts for the controls. In conclusion, the combination exhibited synergistic and bactericidal activities against two MRSA strains after 5 days of treatment. The combination of linezolid plus imipenem appears to be promising for the treatment of severe MRSA infections and merits further investigations to explore the mechanism underlying the synergy between the two drugs.
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Affiliation(s)
- Cédric Jacqueline
- Laboratoire d'Antibiologie, UER de Médecine, 1 rue Gaston Veil, 44035 Nantes, Cedex 01, France
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77
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Jo YW, Im WB, Rhee JK, Shim MJ, Kim WB, Choi EC. Synthesis and antibacterial activity of oxazolidinones containing pyridine substituted with heteroaromatic ring. Bioorg Med Chem 2004; 12:5909-15. [PMID: 15498667 DOI: 10.1016/j.bmc.2004.08.025] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2004] [Revised: 08/18/2004] [Accepted: 08/18/2004] [Indexed: 11/20/2022]
Abstract
A series of oxazolidinone derivatives, which morpholino group of linezolid was replaced with heteroaromatic ring substituted pyridine moiety, were newly synthesized, and their substituted effects on in vitro and in vivo antibacterial activities were evaluated against four problematic gram-positive strains including drug resistant strains and two gram-negative strains. Most compounds exhibited the enhanced in vitro activities with 4-16-fold and three compounds exerted more than 2-fold increased in vivo efficacies than linezolid.
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Affiliation(s)
- Yeong Woo Jo
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 151-742, Korea
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78
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Sbardella G, Mai A, Artico M, Loddo R, Setzu MG, La Colla P. Synthesis and in vitro antimycobacterial activity of novel 3-(1H-pyrrol-1-yl)-2-oxazolidinone analogues of PNU-100480. Bioorg Med Chem Lett 2004; 14:1537-41. [PMID: 15006398 DOI: 10.1016/j.bmcl.2004.01.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2003] [Revised: 11/27/2003] [Accepted: 12/24/2003] [Indexed: 11/19/2022]
Abstract
Pursuing our search program for new antitubercular drugs we decided to explore the potentiality of oxazolidinone moiety by synthesizing novel 3-(1H-pyrrol-1-yl)-2-oxazolidinone analogues of PNU-100480. The new derivatives were tested against atypical mycobacteria as well as against drug resistant Mycobacterium tuberculosis and some of them exhibited a fairly good activity against Mycobacterium avium complex (MAC).
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Affiliation(s)
- Gianluca Sbardella
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Salerno, Via Ponte Don Melillo, 84084 Fisciano (SA), Italy
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79
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80
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Lobritz M, Hutton-Thomas R, Marshall S, Rice LB. Recombination proficiency influences frequency and locus of mutational resistance to linezolid in Enterococcus faecalis. Antimicrob Agents Chemother 2004; 47:3318-20. [PMID: 14506047 PMCID: PMC201147 DOI: 10.1128/aac.47.10.3318-3320.2003] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In vitro linezolid resistance was selected at a higher frequency in Enterococcus faecalis JH2-2 than in recombination-deficient E. faecalis UV202. Resistance in JH2-2 was related to accumulated G2576T mutations in 23S rRNA genes, with the least resistance conferred by mutations in two of four copies. UV202 resistance was associated with a G2505A mutation present in a single copy in mutants with different MICs.
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Affiliation(s)
- Michael Lobritz
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA
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81
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Wagenlehner FME, Wydra S, Onda H, Kinzig-Schippers M, Sörgel F, Naber KG. Concentrations in plasma, urinary excretion, and bactericidal activity of linezolid (600 milligrams) versus those of ciprofloxacin (500 milligrams) in healthy volunteers receiving a single oral dose. Antimicrob Agents Chemother 2004; 47:3789-94. [PMID: 14638484 PMCID: PMC296192 DOI: 10.1128/aac.47.12.3789-3794.2003] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In a randomized crossover study, 12 volunteers (6 males, 6 females) received a single oral dose of 600 mg of linezolid or 500 mg of ciprofloxacin to assess the concentrations in plasma (up to 24 h), urinary excretion (by high-pressure liquid chromatography), and bactericidal titers in urine (UBT) at intervals up to 120 h. The mean maximum concentration of linezolid in plasma was 13.1 mg/liter, and that of ciprofloxacin was 2.46 mg/liter. The median cumulative levels of renal excretion of the administered dose of the parent drug were 44% for linezolid (range, 28 to 47%; mean +/- standard deviation, 40% +/- 7.8%) and 43% for ciprofloxacin (range, 20 to 56%; mean +/- standard deviation, 40% +/- 9.3%). The UBTs, i.e., the highest twofold dilution (with antibiotic-free urine used as the diluent) of urine that was still bactericidal, were determined for a reference strain and five gram-positive clinical uropathogens for which the MICs of linezolid and ciprofloxacin were as follows: Staphylococcus aureus ATCC 27278, 2 and 0.25 mg/liter, respectively; Staphylococcus aureus (methicillin susceptible), 1 and 16 mg/liter, respectively; Staphylococcus aureus (methicillin resistant), 2 and 64 mg/liter, respectively; Staphylococcus saprophyticus (methicillin susceptible), 1 and 0.25 mg/liter, respectively; Enterococcus faecalis, 2 and 1 mg/liter, respectively; and Enterococcus faecium, 2 and 1 mg/liter, respectively. The median UBTs of linezolid measured within the first 6 h were 1:96 for each of the two enterococcal strains and between 1:128 and 1:256 for the four staphylococcal strains. The median UBTs of ciprofloxacin were 1:64 for the two enterococcal strains; between 1:384 and 1:512 for the two ciprofloxacin-susceptible strains; and 1 (bactericidal activity of undiluted urine only) and 1:2 for the two resistant staphylococcal strains, respectively. The areas under the UBT-time curve (AUBT) for linezolid and ciprofloxacin showed no statistically significant (P<0.05) differences except for a better AUBT for linezolid for the two ciprofloxacin-resistant staphylococcal strains. For linezolid there were no statistically significant differences in UBTs or AUBTs for ciprofloxacin-susceptible and -resistant strains. Thus, the bactericidal activities of linezolid and ciprofloxacin against susceptible strains in urine were comparable, whereas linezolid also exhibited the same good bactericidal activity against ciprofloxacin-resistant strains. Therefore, linezolid should be tested for use as empirical treatment for complicated urinary tract infections due to gram-positive uropathogens in an appropriate clinical trial.
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82
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Gravestock MB, Acton DG, Betts MJ, Dennis M, Hatter G, McGregor A, Swain ML, Wilson RG, Woods L, Wookey A. New classes of antibacterial oxazolidinones with C-5, methylene O-Linked heterocyclic side chains. Bioorg Med Chem Lett 2003; 13:4179-86. [PMID: 14622997 DOI: 10.1016/j.bmcl.2003.07.033] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Exploration of the structure-activity relationships of the traditional C-5 acetamidomethyl side chain of the oxazolidonone antibacterials has yielded new, potent series of compounds of which the first examples, the O-linked iosoxazoles are described in detail, leading to the selection of the pre-clinical candidate AZD2563.
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Affiliation(s)
- Michael B Gravestock
- AstraZeneca R&D Boston, Infection Discovery, 35 Gatehouse Park, Waltham, MA 02451, USA.
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83
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Zhang Y, Zhang J, Hoeflich KP, Ikura M, Qing G, Inouye M. MazF Cleaves Cellular mRNAs Specifically at ACA to Block Protein Synthesis in Escherichia coli. Mol Cell 2003; 12:913-23. [PMID: 14580342 DOI: 10.1016/s1097-2765(03)00402-7] [Citation(s) in RCA: 457] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Escherichia coli contains operons called "addiction modules," encoding toxin and antitoxin, which are responsible for growth arrest and cell death. Here, we demonstrate that MazF toxin encoded by "mazEF addiction module" is a sequence-specific (ACA) endoribonuclease functional only for single-stranded RNA. MazF works as a ribonuclease independent of ribosomes, and is, therefore, functionally distinct from RelE, another E. coli toxin, which assists mRNA cleavage at the A site on ribosomes. Upon induction, MazF cleaves whole cellular mRNAs to efficiently block protein synthesis. Purified MazF inhibited protein synthesis in both prokaryotic and eukaryotic cell-free systems. This inhibition was released by MazE, the labile antitoxin against MazF. Thus, MazF functions as a toxic endoribonuclease to interfere with the function of cellular mRNAs by cleaving them at specific sequences leading to rapid cell growth arrest and cell death. The role of such endoribonucleases may have broad implication in cell physiology under various growth conditions.
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Affiliation(s)
- Yonglong Zhang
- Department of Biochemistry, Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, NJ 08854, USA
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84
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Abstract
Functional RNAs such as ribosomal RNA and structured domains of mRNA are targets for small molecule ligands that can act as modulators of the RNA biological activity. Natural ligands for RNA display a bewildering structural and chemical complexity that has yet to be matched by synthetic RNA binders. Comparison of natural and artificial ligands for RNA may help to direct future approaches to design and synthesize potent novel scaffolds for specific recognition of RNA targets.
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Affiliation(s)
- Thomas Hermann
- Department of Computational Chemistry & Structure, Anadys Parmaceuticals, Inc., 9050 Camino Santa Fe, San Diego, CA 92121, USA.
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85
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Colca JR, McDonald WG, Waldon DJ, Thomasco LM, Gadwood RC, Lund ET, Cavey GS, Mathews WR, Adams LD, Cecil ET, Pearson JD, Bock JH, Mott JE, Shinabarger DL, Xiong L, Mankin AS. Cross-linking in the living cell locates the site of action of oxazolidinone antibiotics. J Biol Chem 2003; 278:21972-9. [PMID: 12690106 DOI: 10.1074/jbc.m302109200] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Oxazolidinone antibiotics, an important new class of synthetic antibacterials, inhibit protein synthesis by interfering with ribosomal function. The exact site and mechanism of oxazolidinone action has not been elucidated. Although genetic data pointed to the ribosomal peptidyltransferase as the primary site of drug action, some biochemical studies conducted in vitro suggested interaction with different regions of the ribosome. These inconsistent observations obtained in vivo and in vitro have complicated the understanding of oxazolidinone action. To localize the site of oxazolidinone action in the living cell, we have cross-linked a photoactive drug analog to its target in intact, actively growing Staphylococcus aureus. The oxazolidinone cross-linked specifically to 23 S rRNA, tRNA, and two polypeptides. The site of cross-linking to 23 S rRNA was mapped to the universally conserved A-2602. Polypeptides cross-linked were the ribosomal protein L27, whose N terminus may reach the peptidyltransferase center, and LepA, a protein homologous to translation factors. Only ribosome-associated LepA, but not free protein, was cross-linked, indicating that LepA was cross-linked by the ribosome-bound antibiotic. The evidence suggests that a specific oxazolidinone binding site is formed in the translating ribosome in the immediate vicinity of the peptidyltransferase center.
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Affiliation(s)
- Jerry R Colca
- Pharmacia Corporation, 301 Henrietta Street, Kalamazoo, MI 49001, USA.
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86
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Perrault WR, Pearlman BA, Godrej DB, Jeganathan A, Yamagata K, Chen JJ, Lu CV, Herrinton PM, Gadwood RC, Chan L, Lyster MA, Maloney MT, Moeslein JA, Greene ML, Barbachyn MR. The Synthesis of N-Aryl-5(S)-aminomethyl-2-oxazolidinone Antibacterials and Derivatives in One Step from Aryl Carbamates. Org Process Res Dev 2003. [DOI: 10.1021/op034028h] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- William R. Perrault
- Early Chemical Process Research and Development, Chemical Process Research and Development, and Medicinal Chemistry Research, Pharmacia Corporation, Kalamazoo, Michigan 49001, U.S.A
| | - Bruce A. Pearlman
- Early Chemical Process Research and Development, Chemical Process Research and Development, and Medicinal Chemistry Research, Pharmacia Corporation, Kalamazoo, Michigan 49001, U.S.A
| | - Delara B. Godrej
- Early Chemical Process Research and Development, Chemical Process Research and Development, and Medicinal Chemistry Research, Pharmacia Corporation, Kalamazoo, Michigan 49001, U.S.A
| | - Azhwarsamy Jeganathan
- Early Chemical Process Research and Development, Chemical Process Research and Development, and Medicinal Chemistry Research, Pharmacia Corporation, Kalamazoo, Michigan 49001, U.S.A
| | - Koji Yamagata
- Early Chemical Process Research and Development, Chemical Process Research and Development, and Medicinal Chemistry Research, Pharmacia Corporation, Kalamazoo, Michigan 49001, U.S.A
| | - Jiong J. Chen
- Early Chemical Process Research and Development, Chemical Process Research and Development, and Medicinal Chemistry Research, Pharmacia Corporation, Kalamazoo, Michigan 49001, U.S.A
| | - Cuong V. Lu
- Early Chemical Process Research and Development, Chemical Process Research and Development, and Medicinal Chemistry Research, Pharmacia Corporation, Kalamazoo, Michigan 49001, U.S.A
| | - Paul M. Herrinton
- Early Chemical Process Research and Development, Chemical Process Research and Development, and Medicinal Chemistry Research, Pharmacia Corporation, Kalamazoo, Michigan 49001, U.S.A
| | - Robert C. Gadwood
- Early Chemical Process Research and Development, Chemical Process Research and Development, and Medicinal Chemistry Research, Pharmacia Corporation, Kalamazoo, Michigan 49001, U.S.A
| | - Lai Chan
- Early Chemical Process Research and Development, Chemical Process Research and Development, and Medicinal Chemistry Research, Pharmacia Corporation, Kalamazoo, Michigan 49001, U.S.A
| | - Mark A. Lyster
- Early Chemical Process Research and Development, Chemical Process Research and Development, and Medicinal Chemistry Research, Pharmacia Corporation, Kalamazoo, Michigan 49001, U.S.A
| | - Mark T. Maloney
- Early Chemical Process Research and Development, Chemical Process Research and Development, and Medicinal Chemistry Research, Pharmacia Corporation, Kalamazoo, Michigan 49001, U.S.A
| | - Jeffery A. Moeslein
- Early Chemical Process Research and Development, Chemical Process Research and Development, and Medicinal Chemistry Research, Pharmacia Corporation, Kalamazoo, Michigan 49001, U.S.A
| | - Meredith L. Greene
- Early Chemical Process Research and Development, Chemical Process Research and Development, and Medicinal Chemistry Research, Pharmacia Corporation, Kalamazoo, Michigan 49001, U.S.A
| | - Michael R. Barbachyn
- Early Chemical Process Research and Development, Chemical Process Research and Development, and Medicinal Chemistry Research, Pharmacia Corporation, Kalamazoo, Michigan 49001, U.S.A
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87
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Eliopoulos GM. Quinupristin-dalfopristin and linezolid: evidence and opinion. Clin Infect Dis 2003; 36:473-81. [PMID: 12567306 DOI: 10.1086/367662] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2002] [Accepted: 11/07/2002] [Indexed: 11/03/2022] Open
Abstract
Quinupristin-dalfopristin and linezolid demonstrate in vitro activity against a wide range of gram-positive bacteria, including many isolates resistant to earlier antimicrobials. Quinupristin-dalfopristin is inactive against Enterococcus faecalis but has been effective for treatment of infections due to vancomycin-resistant Enterococcus faecium associated with bacteremia. In comparative trials, linezolid proved to be equivalent to comparator agents, resulting in its approval for several clinical indications. The almost-complete bioavailability of linezolid permits oral administration. Each agent can cause adverse effects that may limit use in individual patients. Resistance to these drugs has been encountered infrequently among vancomycin-resistant E. faecium. Resistance to quinupristin-dalfopristin is rare among staphylococci in the United States, and resistance to linezolid is very rare. Whether there is any benefit to use of these agents in combination regimens, and whether there are circumstances in which they might be alternatives to cell-wall active antibiotics for treatment of bone or endovascular infections, are questions that deserve further study.
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Affiliation(s)
- George M Eliopoulos
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.
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88
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Phillips OA, Udo EE, Ali AAM, Al-Hassawi N. Synthesis and antibacterial activity of 5-substituted oxazolidinones. Bioorg Med Chem 2003; 11:35-41. [PMID: 12467705 DOI: 10.1016/s0968-0896(02)00423-6] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A series of 5-substituted oxazolidinones with varying substitution at the 5-position of the oxazolidinone ring were synthesized and their in vitro antibacterial activity was evaluated. The compounds demonstrated potent to weak antibacterial activity. A novel compound (PH-027) demonstrated potent antibacterial activity, which is comparable to or better than those of linezolid and vancomycin against antibiotic-susceptible standard and clinically isolated resistant strains of gram-positive bacteria. Although the presence of the C-5-acetamidomethyl functionality at the C-5 position of the oxazolidinones has been widely claimed and reported as a structural requirement for optimal antimicrobial activity in the oxazolidinone class of compounds, our results from this work identified the C-5 triazole substitution as a new structural alternative for potent antibacterial activity in the oxazolidinone class.
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Affiliation(s)
- O A Phillips
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Kuwait University, PO Box 24923, Safat 13110, Kuwait.
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89
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Jacqueline C, Batard E, Perez L, Boutoille D, Hamel A, Caillon J, Kergueris MF, Potel G, Bugnon D. In vivo efficacy of continuous infusion versus intermittent dosing of linezolid compared to vancomycin in a methicillin-resistant Staphylococcus aureus rabbit endocarditis model. Antimicrob Agents Chemother 2002; 46:3706-11. [PMID: 12435665 PMCID: PMC132754 DOI: 10.1128/aac.46.12.3706-3711.2002] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Linezolid is the first drug issued from the oxazolidinones, a novel class of antimicrobial agents with potent activity against gram-positive pathogens. A rabbit endocarditis model was used to compare the in vivo activities of different linezolid regimens mimicking intermittent dosing of 10 mg/kg of body weight every 12 h for 5 days or continuous (constant-rate) infusion of a daily dose of 20 mg/kg (for 5 days) or 40 mg/kg (for 3 and 5 days) and the activities of intermittent dosing and continuous infusion of vancomycin (for 5 days). The in vivo activities of these regimens were tested against three strains of methicillin-resistant Staphylococcus aureus. A human-like pharmacokinetic simulation was used for linezolid in order to improve the extrapolation of the results to human therapy. All linezolid regimens significantly reduced the numbers of S. aureus cells in aortic valve vegetations compared to the numbers in the control groups. Linezolid intermittent dosing had an in vivo bacteriostatic effect. Switching from intermittent dosing to continuous infusion (at the same dose) led to in vivo bactericidal activity, with a decrease of at least 3 log(10) CFU/g of vegetation compared to the counts for the controls. After 5 days of treatment, continuous infusion of linezolid (corresponding to a daily dose of 40 mg/kg in humans) seemed to be at least as effective as vancomycin against the three strains. No resistant variant was isolated from the vegetations during any of the treatments. These data suggest that continuous infusion of linezolid could be an appropriate alternative to the use of glycopeptides for the treatment of severe methicillin-resistant S. aureus infections.
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Affiliation(s)
- Cédric Jacqueline
- Laboratoire d'Antibiologie (UPRES EA-1156), Faculté de Médecine, 44035 Nantes, Cedex 01, France
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90
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Sander P, Belova L, Kidan YG, Pfister P, Mankin AS, Böttger EC. Ribosomal and non-ribosomal resistance to oxazolidinones: species-specific idiosyncrasy of ribosomal alterations. Mol Microbiol 2002; 46:1295-304. [PMID: 12453216 DOI: 10.1046/j.1365-2958.2002.03242.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A derivative of Mycobacterium smegmatis, which carries only one functional rRNA (rrn) operon, was used to isolate mutants resistant to the ribosome-targeted antibiotic linezolid. Isolation and characterization of linezolid-resistant clones revealed two classes of mutants. Ribosomes from class I mutants are resistant to oxazolidinones in an in vitro peptidyl transferase assay, indicating that resistance maps to the ribosome component. In contrast, ribosomes from class II mutants show wild-type susceptibility to a linezolid derivative in vitro, pointing to a non-ribosomal mechanism of resistance. Introduction of a wild-type ribosomal RNA operon into linezolid-resistant strains restored linezolid sensitivity in class I mutants, indicating that resistance (i) maps to the rRNA and (ii) is recessive. Sequencing of the entire rrn operon identified a single nucleotide alteration in 23S rRNA of class I mutant strains, 2447G --> T (Escherichia coli numbering). Introduction of mutant rrl2447T into M. smegmatis rrn- resulted in a linezolid-resistant phenotype, demonstrating a cause-effect relationship of the 2447G --> T alteration. The 2447G --> T mutation, which renders M. smegmatis linezolid resistant, confers lethality in E. coli. This finding is strong evidence of structural and pos-sibly functional differences between the ribosomes of Gram-positive and Gram-negative bacteria. In agreement with the results of the in vitro assay, class II mutants show a wild-type sequence of the complete rRNA operon. The lack of cross-resistance of the class II mutants to other antibiotics suggests a resistance mechanism other than activation of a broad-spectrum multidrug transporter.
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MESH Headings
- Acetamides/pharmacology
- Anti-Bacterial Agents/pharmacology
- Base Sequence
- Drug Resistance, Bacterial
- Drug Resistance, Microbial
- Escherichia coli/chemistry
- Escherichia coli/genetics
- Linezolid
- Microbial Sensitivity Tests
- Molecular Sequence Data
- Mutation
- Mycobacterium smegmatis/drug effects
- Mycobacterium smegmatis/genetics
- Oxazolidinones/pharmacology
- RNA, Bacterial/chemistry
- RNA, Bacterial/drug effects
- RNA, Bacterial/genetics
- RNA, Ribosomal, 23S/chemistry
- RNA, Ribosomal, 23S/drug effects
- RNA, Ribosomal, 23S/genetics
- Ribosomes/drug effects
- Species Specificity
- rRNA Operon/drug effects
- rRNA Operon/genetics
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Affiliation(s)
- P Sander
- Institut für Medizinische Mikrobiologie, Universität Zürich, Gloriastr. 30/32, CH-8028 Zürich, Switzerland
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