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Luis R Domingo, Mar Ríos-Gutiérrez, Patricia Pérez
The molecular mechanism of the carbenoid-type [3 + 2] cycloaddition (32CA) reactions of a nitrile ylide (NY) with a non-chiral and a chiral oxazolidinone has been studied within Molecular Electron Density Theory (MEDT) at the MPWB1K/6-31G(d) computational level. Topological analysis of the Electron Localisation Function (ELF) of the NY shows that it presents a carbenoid structure. The high nucleophilic character of the NY together with the electrophilic character of the non-chiral oxazolidinone favour a polar 32CA reaction with a very low activation energy, the reaction being completely meta/endo selective...
October 18, 2016: Organic & Biomolecular Chemistry
Hongxia Zhao, Wuxia Guo, Wenna Quan, Jingqiu Jiang, Baocheng Qu
The occurrence and levels of nitrofuran metabolites (NFMs) in sea cucumber (SC) from Dalian, China, are reported. Four metabolites including 3-amino-5-morpholinomethyl-2-oxazolidinone (AMOZ), 3-amino-2-oxazolidinone (AOZ), semicarbazide (SEM) and 1-aminohydantoin (AHD) in different SC products (fresh, instant and dry salted SCs) were measured. The frequency of occurrence for NFMs in all SC samples was 42.7%. The total NFM concentrations ranged from non-detectable to 64.6 ng g(-)(1), with a mean of 3.59 ng g(-1)...
October 17, 2016: Food Additives & Contaminants. Part A, Chemistry, Analysis, Control, Exposure & Risk Assessment
Rosario Musumeci, Enrico Calaresu, Jolanda Gerosa, Davide Oggioni, Simone Bramati, Patrizia Morelli, Ida Mura, Andrea Piana, Bianca Maria Are, Clementina Elvezia Cocuzza
Linezolid is the main representative of the oxazolidinones, introduced in 2000 in clinical practice to treat severe Gram-positive infections. This compound inhibits protein synthesis by binding to the peptidyl transferase centre of the 50S bacterial ribosomal subunit. The aim of this study was to characterize 12 clinical strains of linezolid-resistant Staphylococcus spp. isolated in Northern Italy. All isolates of Staphylococcus spp. studied showed a multi-antibiotic resistance phenotype. In particular, all isolates showed the presence of the mecA gene associated with SSCmec types IVa, V or I...
September 13, 2016: New Microbiologica
Rustam Aminov
The introduction of antibiotics into clinical practice revolutionized the treatment and management of infectious diseases. Before the introduction of antibiotics, these diseases were the leading cause of morbidity and mortality in human populations. This review presents a brief history of discovery of the main antimicrobial classes (arsphenamines, β-lactams, sulphonamides, polypeptides, aminoglycosides, tetracyclines, amphenicols, lipopeptides, macrolides, oxazolidinones, glycopeptides, streptogramins, ansamycins, quinolones, and lincosamides) that have changed the landscape of contemporary medicine...
October 5, 2016: Biochemical Pharmacology
Jingdong Shi, Ying Jiang, Yanfang Zhao
The objective of this study was to investigate the prevalence of drug-resistant Helicobacter pylori in Beijing Tian Tan Hospital (Beijing, China) and to determine the susceptibility of H. pylori to linezolid and novel oxazolidinone analogues. Minimum inhibitory concentrations (MICs) of amoxicillin, clarithromycin, metronidazole, ciprofloxacin, tetracycline and levofloxacin against H. pylori were determined by Etest. The in vitro antibacterial activities of linezolid and novel oxazolidinone analogues were assessed by the disk diffusion method...
September 15, 2016: Journal of Global Antimicrobial Resistance
Rosa Padilla, Verónica Salazar-Pereda, Daniel Mendoza-Espinosa, José M Vásquez-Pérez, Noemí Andrade-López, Joaquín Tamariz, José G Alvarado-Rodríguez, Julián Cruz-Borbolla
The Ir(i) complexes [Tp(Me2)Ir(η(4)-1,4-diene)] 2b and 2c react thermally with a variety of aromatic aldehydes, 3a-e, to generate the metallabicyclic compounds 4e-k and the Fischer-type carbenes 5a-b in moderate yields. These reactions are proposed to take place with the initial formation of η(1)-aldehyde adducts as key intermediates. The formation of the metallabicyclic compounds 4e-k involves a formal decarboxylation process at the exo-2-oxazolidinone diene and an ortho metallation of the aromatic ring...
September 29, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
Zhoujie Luo, Binsen Wang, Yuan Liu, Guohua Gao, Fei Xia
The mechanisms of the one-pot conversion of carbon dioxide, ethylene oxide, and aniline to 3-phenyl-2-oxazolidionone catalyzed by the binary ionic liquids of BmimBr and BmimOAc were explored using the DFT methods. The complex reaction above comprises of two parallel reactions and a subsequent cascade reaction. DFT calculations on reaction pathways and energy profiles reveal that the electrostatic and hydrogen-bond effects of BmimBr play a crucial role in the parallel reactions for the generation of ethylene carbonate and 2-phenylamino-ethanol...
October 12, 2016: Physical Chemistry Chemical Physics: PCCP
D J Biedenbach, S K Bouchillon, B Johnson, J Alder, D F Sahm
Tedizolid is an oxazolidinone with an antimicrobial in vitro potency advantage against Gram-positive bacterial pathogens compared to other currently marketed drugs in this class, including linezolid. Tedizolid was compared to linezolid when tested against Staphylococcus aureus and Streptococcus pneumoniae isolates collected from countries in Latin America and the Asia-Pacific. Isolates were tested by broth microdilution susceptibility methods against tedizolid, linezolid, and non-class comparators in accordance with the Clinical and Laboratory Standards Institute (CLSI) guidelines...
September 27, 2016: European Journal of Clinical Microbiology & Infectious Diseases
Lucia Ferrazzano, Angelo Viola, Elena Lonati, Alessandra Bulbarelli, Rosario Musumeci, Clementina Cocuzza, Marco Lombardo, Alessandra Tolomelli
Among the different classes of antibiotics, oxazolidinone derivatives represent important drugs, since their unique mechanism of action overcomes commonly diffused multidrug-resistant bacteria. Anyway, the structural similarity of these molecules to monoamino oxidase (MAO) inhibitors, like toloxatone and blefoxatone, induces in many cases loss of selectivity as a major concern. A small library of compounds based on isoxazolidinone and dehydro-β-proline scaffold was designed with the aim to obtain antibacterial agents, evaluating at the same time the potential effects of structural features on MAO inhibitory behaviour...
September 4, 2016: European Journal of Medicinal Chemistry
Run Fan, Dexi Li, Yang Wang, Tao He, Andrea T Feßler, Stefan Schwarz, Congming Wu
A total of 57 methicillin-resistant Staphylococcus aureus (MRSA) isolates and 475 methicillin-resistant coagulase-negative staphylococci (MRCoNS) collected from pigs in the Guangdong province of China in 2014 were investigated for the presence of the novel oxazolidinone-phenicol resistance gene optrA The optrA gene was detected in 6.9% (n=33) of the MRCoNS, all of which were MR-Staphylococcus sciuri, but in none of the MRSA. Five optrA-carrying MR-S. sciuri also harbored the multiresistance gene cfr Pulsed-field gel electrophoresis (PFGE) and dru typing of the 33 optrA-carrying MR-S...
September 26, 2016: Antimicrobial Agents and Chemotherapy
Tarani Kanta Barman, Manoj Kumar, Tarun Mathur, Tridib Chaira, G Ramkumar, Vandana Kalia, Madhvi Rao, Manisha Pandya, Ajay Singh Yadav, Biswajit Das, Dilip J Upadhyay, Hamidullah, Rituraj Konwar, V Samuel Raj, Harpal Singh
RBx 11760, a bi-aryl oxazolidinone was investigated for antibacterial activity against Gram positive bacteria. The MIC90 (mg/L) of RBx 11760 and linezolid against Staphylococcus aureus were: 2 and 4, Staphylococcus epidermidis: 0.5 and 2, Enterococcus: 1 and 4, respectively. Similarly against Streptococcus pneumoniae MIC90 was: 0.5 and 2, respectively. In time-kill studies, RBx 11760, tedizolid and linezolid exhibited bacteriostatic effect except S. pneumoniae RBx 11760 showed 2-log10 kill at 4 X MIC while tedizolid and linezolid showed 2 log10 and 1...
September 19, 2016: Antimicrobial Agents and Chemotherapy
Lanqing Cui, Yang Wang, Yuan Lv, Shan Wang, Yunjia Song, Yun Li, Jian Liu, Feng Xue, Weiwei Yang, Jia Zhang
2201 non-duplicate enterococcal isolates collected from 29 hospitals in 23 cities in China between 2004 and 2014 were screened for oxazolidinone resistance gene optrA. 45 isolates (2.0%) were optrA positive with 11 OptrA variants identified. The positive rate of optrA increased from 0.4% to 3.9% during the 10-year surveillance period. PFGE and MLST analysis revealed that 37 optrA-positive Enterococcus faecalis clustered into 25 PFGE patterns and 21 sequence types, while 6 Enterococcus faecium isolates represented 6 PFGE patterns and 6 sequence types...
September 19, 2016: Antimicrobial Agents and Chemotherapy
Wenqing Hu, Bing Shi, Lihui Liu, Shengke He, Liping Ye, DengMei Tian, Yongqing Zhang
Linezolid (LZD), severed as the first oxazolidinone antibiotic, was active against multidrug-resistant gram-positive strains. LZD can induce thrombocytopenia, anemia and leukocytopenia. Currently, reports on pure red cell aplasia (PRCA) cases induced by LZD are relatively rare (4-7). In this paper, we reported a patient with PRCA twice induced by LZD. A 37-year-old man was diagnosed with myelodysplatic syndrome (MDS) and underwent allo-HSCT from an unrelated donor with ABO blood type and leukocyte antigen (HLA)-matching...
2016: Iranian Journal of Pharmaceutical Research: IJPR
Khuloud Takrouri, Harold D Cooper, Andrew Spaulding, Paola Zucchi, Bilyana Koleva, Dillon C Cleary, Westley Tear, Penny J Beuning, Elizabeth B Hirsch, James B Aggen
Novel antibacterials with activity against the Gram-negative bacteria associated with nosocomial infections, including Escherichia coli and other Enterobacteriaceae, are urgently needed due to the increasing prevalence of multidrug-resistant strains. A major obstacle that has stalled progress on nearly all small-molecule classes with potential for activity against these species has been achieving sufficient whole-cell activity, a difficult challenge due to the formidable outer membrane and efflux barriers intrinsic to these species...
June 10, 2016: ACS Infectious Diseases
Sarah J Cully, Thomas E Storr, Michael J Rawling, Induka R Abeysena, Daniel Hamza, Geraint Jones, Christopher A Pearce, Abdul Quddus, William Lewis, Robert A Stockman
In order to address the current downturn in the drug discovery pipeline, initiatives are being undertaken to synthesise screening libraries of sp(3)-rich, low molecular weight compounds. As part of the European Lead Factory initiative, the synthesis and derivatisation of a simple hexahydrooxazolo[5,4-c]pyridin-2(1H)-one bicyclic carbamate has been achieved. The synthetic route employed involved a telescoped hetero-Diels-Alder/[2,3]-sigmatropic rearrangement/cyclisation sequence to deliver the desired core scaffold containing two points for further diversification...
November 1, 2016: Bioorganic & Medicinal Chemistry
V Pintado
The lack of new antibiotics for multidrug-resistant bacteria is a matter of concern in microorganisms such as Pseudomonas aeruginosa, ESBL- and carbapenemase-producing Enterobacteriaceae, Acinetobacter baumannii, methicillin-resistant Staphylococcous aureus and vancomycin-resistant Enterococcus faecium. This situation has conditioned the reuse of "old" antibiotics (colistin, fosfomycin), the use of more recent antibiotics with new indications or dosage regimens (tigecycline, meropenem) and the introduction of "new" antibiotics (β-lactams, lipoglycopeptides, oxazolidinones) that are the subject of this review...
September 2016: Revista Española de Quimioterapia: Publicación Oficial de la Sociedad Española de Quimioterapia
Izabel L Miranda, Ítala K B Lopes, Marisa A N Diaz, Gaspar Diaz
(-)-Cytoxazone, originally isolated from cultures of a Streptomyces species has an oxazolidin-2-one 4,5-disubstituted ring. It is known that this natural product presents a cytokine modulator effect through the signaling pathway of Th2 cells (type 2 cytokines), which are involved in the process of growth and differentiation of cells. From this, the interest in the development of research aimed at the total synthesis of this molecule and its analogs has remained high, which can be confirmed by the large number of publications on the topic, more than 30 to date...
2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Atul A Dhavan, Rahul D Kaduskar, Loana Musso, Leonardo Scaglioni, Piera Anna Martino, Sabrina Dallavalle
The first total synthesis of leopolic acid A, a fungal metabolite with a rare 2,3-pyrrolidinedione nucleus linked to an ureido dipeptide, was designed and carried out. Crucial steps for the strategy include a Dieckmann cyclization to obtain the 2,3-pyrrolidinedione ring and a Wittig olefination to install the polymethylene chain. An oxazolidinone-containing leopolic acid A analogue was also synthesized. The antibacterial activity showed by both compounds suggests that they could be considered as promising candidates for future developments...
2016: Beilstein Journal of Organic Chemistry
Jennifer J Furin, Jeannine Du Bois, Elana van Brakel, Phalkun Chheng, Amour Venter, Charles A Peloquin, Abdullah Alsultan, Bonnie Thiel, Sara M Debanne, W Henry Boom, Andreas H Diacon, John L Johnson
RATIONALE: AZD5847 is an oxazolidinone antibiotic, with in vitro activity against Mycobacterium tuberculosis OBJECTIVES: To evaluate the antimycobacterial activity, safety, and pharmacokinetics of AZD5847 in patients with pulmonary tuberculosis. METHODS: Groups of 15 treatment-naive, sputum smear-positive adults with pulmonary tuberculosis were randomly assigned to AZD5847 at 4 doses (500 mg once daily, 500 mg twice daily, 1200 mg once daily and 800 mg twice daily) or daily standard chemotherapy...
August 22, 2016: Antimicrobial Agents and Chemotherapy
Warren S Joseph, Darren Culshaw, Steven Anuskiewicz, Carisa De Anda, Philippe Prokocimer
BACKGROUND: Tedizolid phosphate, the prodrug of the oxazolidinone tedizolid, has been approved in a number of countries, including the United States, those in the European Union, and Canada, for treatment of patients with acute bacterial skin and skin structure infections (ABSSSI). Two Phase 3 trials demonstrated the noninferior efficacy of tedizolid (200 mg once daily for 6 days) to linezolid (600 mg twice daily for 10 days) in patients with ABSSSI. Because of the challenges of treating lower-extremity ABSSSI, the efficacy and safety of tedizolid and linezolid for treating lower extremity versus non-lower extremity infections were compared...
August 17, 2016: Journal of the American Podiatric Medical Association
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