Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 257
Filter
1.
Water Res ; 230: 119500, 2023 Feb 15.
Article in English | MEDLINE | ID: mdl-36640613

ABSTRACT

A detailed characterization of residential water consumption is essential for ensuring urban water systems' capability to cope with changing water resources availability and water demands induced by growing population, urbanization, and climate change. Several studies have been conducted in the last decades to investigate the characteristics of residential water consumption with data at a sufficiently fine temporal resolution for grasping individual end uses of water. In this paper, we systematically review 114 studies to provide a comprehensive overview of the state-of-the-art research about water consumption at the end-use level. Specifically, we contribute with: (1) an in-depth discussion of the most relevant findings of each study, highlighting which water end-use characteristics were so far prioritized for investigation in different case studies and water demand modelling and management studies from around the world; and (2) a multi-level analysis to qualitatively and quantitatively compare the most common results available in the literature, i.e. daily per capita end-use water consumption, end-use parameter average values and statistical distributions, end-use daily profiles, end-use determinants, and considerations about efficiency and diffusion of water-saving end uses. Our findings can support water utilities, consumers, and researchers (1) in understanding which key aspects of water end uses were primarily investigated in the last decades; and (2) in exploring their main features considering different geographical, cultural, and socio-economic regions of the world.


Subject(s)
Urbanization , Water , Water Supply , Water Resources
2.
Antimicrob Agents Chemother ; 66(12): e0092122, 2022 12 20.
Article in English | MEDLINE | ID: mdl-36448795

ABSTRACT

CUO246, a novel DNA gyrase/topoisomerase IV inhibitor, is active in vitro against a broad range of Gram-positive, fastidious Gram-negative, and atypical bacterial pathogens and retains activity against quinolone-resistant strains in circulation. The frequency of selection for single step mutants of wild-type S. aureus with reduced susceptibility to CUO246 was <4.64 × 10-9 at 4× and 8× MIC and remained low when using an isogenic QRDR mutant (<5.24 × 10-9 at 4× and 8× MIC). Biochemical assays indicated that CUO246 had potent inhibitory activity against both DNA gyrase (GyrAB) and topoisomerase IV (ParCE). Furthermore, CUO246 showed rapid bactericidal activity in time-kill assays and potent in vivo efficacy against S. aureus in a neutropenic murine thigh infection model. These results suggest that CUO246 may be useful in treating infections by various causative agents of acute skin and skin structure infections, respiratory tract infections, and sexually transmitted infections.


Subject(s)
DNA Gyrase , DNA Topoisomerase IV , Animals , Mice , DNA Gyrase/genetics , DNA Topoisomerase IV/genetics , Topoisomerase II Inhibitors/pharmacology , DNA, Bacterial , Staphylococcus aureus , Microbial Sensitivity Tests , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use
3.
Anaesthesia ; 77(3): 264-276, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34647323

ABSTRACT

Despite the acknowledged injustice and widespread existence of parachute research studies conducted in low- or middle-income countries by researchers from institutions in high-income countries, there is currently no pragmatic guidance for how academic journals should evaluate manuscript submissions and challenge this practice. We assembled a multidisciplinary group of editors and researchers with expertise in international health research to develop this consensus statement. We reviewed relevant existing literature and held three workshops to present research data and holistically discuss the concept of equitable authorship and the role of academic journals in the context of international health research partnerships. We subsequently developed statements to guide prospective authors and journal editors as to how they should address this issue. We recommend that for manuscripts that report research conducted in low- or middle-income countries by collaborations including partners from one or more high-income countries, authors should submit accompanying structured reflexivity statements. We provide specific questions that these statements should address and suggest that journals should transparently publish reflexivity statements with accepted manuscripts. We also provide guidance to journal editors about how they should assess the structured statements when making decisions on whether to accept or reject submitted manuscripts. We urge journals across disciplines to adopt these recommendations to accelerate the changes needed to halt the practice of parachute research.


Subject(s)
Authorship/standards , Biomedical Research/standards , Editorial Policies , Global Health/standards , Periodicals as Topic/standards , Africa , Australia , Biomedical Research/trends , Global Health/trends , Humans , Periodicals as Topic/trends , Review Literature as Topic , United Kingdom
4.
J Med Chem ; 64(9): 6329-6357, 2021 05 13.
Article in English | MEDLINE | ID: mdl-33929852

ABSTRACT

Herein, we describe the discovery and optimization of a novel series that inhibits bacterial DNA gyrase and topoisomerase IV via binding to, and stabilization of, DNA cleavage complexes. Optimization of this series led to the identification of compound 25, which has potent activity against Gram-positive bacteria, a favorable in vitro safety profile, and excellent in vivo pharmacokinetic properties. Compound 25 was found to be efficacious against fluoroquinolone-sensitive Staphylococcus aureus infection in a mouse thigh model at lower doses than moxifloxacin. An X-ray crystal structure of the ternary complex formed by topoisomerase IV from Klebsiella pneumoniae, compound 25, and cleaved DNA indicates that this compound does not engage in a water-metal ion bridge interaction and forms no direct contacts with residues in the quinolone resistance determining region (QRDR). This suggests a structural basis for the reduced impact of QRDR mutations on antibacterial activity of 25 compared to fluoroquinolones.


Subject(s)
Anti-Bacterial Agents/pharmacology , DNA Gyrase/metabolism , DNA Topoisomerase IV/antagonists & inhibitors , Drug Design , Fluoroquinolones/pharmacology , Staphylococcus aureus/drug effects , Topoisomerase II Inhibitors/pharmacology , Animals , Anti-Bacterial Agents/chemistry , Drug Resistance, Bacterial/drug effects , Mice , Topoisomerase II Inhibitors/chemistry
5.
PLoS One ; 15(10): e0241388, 2020.
Article in English | MEDLINE | ID: mdl-33119677

ABSTRACT

Radiation for pelvic cancers can result in severe bladder damage and radiation cystitis (RC), which is characterized by chronic inflammation, fibrosis, and vascular damage. RC development is poorly understood because bladder biopsies are difficult to obtain. The goal of this study is to gain understanding of molecular changes that drive radiation-induced cystitis in cancer survivors using urine samples from prostate cancer survivors with history of radiation therapy. 94 urine samples were collected from prostate cancer survivors with (n = 85) and without (n = 9) history of radiation therapy. 15 patients with radiation history were officially diagnosed with radiation cystitis. Levels of 47 different proteins were measured using Multiplex Luminex. Comparisons were made between non-irradiated and irradiated samples, and within irradiated samples based on radiation cystitis diagnosis, symptom scores or hematuria. Statistical analysis was performed using Welch's t-test. In prostate cancer survivors with history of radiation therapy, elevated levels of PAI 1, TIMP1, TIMP2, HGF and VEGF-A were detected in patients that received a radiation cystitis diagnosis. These proteins were also increased in patients suffering from hematuria or high symptom scores. No inflammatory proteins were detected in the urine, except in patients with gross hematuria and end stage radiation cystitis. Active fibrosis and vascular distress is detectable in the urine through elevated levels of associated proteins. Inflammation is only detected in urine of patients with end-stage radiation cystitis disease. These results suggest that fibrosis and vascular damage drive the development of radiation cystitis and could lead to the development of more targeted treatments.


Subject(s)
Blood Vessels/radiation effects , Cancer Survivors , Cystitis/urine , Prostatic Neoplasms/radiotherapy , Proteinuria/complications , Radiation Injuries/urine , Cystitis/complications , Cystitis/etiology , Cystitis/pathology , Fibrosis , Humans , Male , Middle Aged , Radiation Injuries/complications , Radiation Injuries/etiology , Radiation Injuries/pathology
6.
Nervenarzt ; 91(11): 1017-1024, 2020 Nov.
Article in German | MEDLINE | ID: mdl-32930813

ABSTRACT

The article provides an overview of racism discourses in research and clinical practice in the health sector and discusses the individual and institutional effects of racism and discrimination on mental health. In addition, suggestions are provided as to which racism critical transformations in healthcare structures for mentally ill persons are necessary in order to enable equitable participation for people affected by discrimination and racism.


Subject(s)
Mentally Ill Persons , Racism , Delivery of Health Care , Humans , Mental Health
7.
J Med Chem ; 63(14): 7773-7816, 2020 07 23.
Article in English | MEDLINE | ID: mdl-32634310

ABSTRACT

Since their discovery over 5 decades ago, quinolone antibiotics have found enormous success as broad spectrum agents that exert their activity through dual inhibition of bacterial DNA gyrase and topoisomerase IV. Increasing rates of resistance, driven largely by target-based mutations in the GyrA/ParC quinolone resistance determining region, have eroded the utility and threaten the future use of this vital class of antibiotics. Herein we describe the discovery and optimization of a series of 4-(aminomethyl)quinolin-2(1H)-ones, exemplified by 34, that inhibit bacterial DNA gyrase and topoisomerase IV and display potent activity against ciprofloxacin-resistant Gram-negative pathogens. X-ray crystallography reveals that 34 occupies the classical quinolone binding site in the topoisomerase IV-DNA cleavage complex but does not form significant contacts with residues in the quinolone resistance determining region.


Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial/drug effects , Fluoroquinolones/pharmacology , Gram-Negative Bacteria/drug effects , Topoisomerase II Inhibitors/pharmacology , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/metabolism , Anti-Bacterial Agents/toxicity , Binding Sites , Cell Line, Tumor , DNA Gyrase/metabolism , DNA Topoisomerase IV/antagonists & inhibitors , DNA Topoisomerase IV/chemistry , Fluoroquinolones/chemical synthesis , Fluoroquinolones/metabolism , Fluoroquinolones/toxicity , Gram-Negative Bacteria/enzymology , Humans , Microbial Sensitivity Tests , Molecular Structure , Structure-Activity Relationship , Topoisomerase II Inhibitors/chemical synthesis , Topoisomerase II Inhibitors/metabolism , Topoisomerase II Inhibitors/toxicity
9.
ACS Infect Dis ; 5(10): 1688-1692, 2019 10 11.
Article in English | MEDLINE | ID: mdl-31478369

ABSTRACT

Monobactam antibiotic 1 is active against Gram-negative bacteria even though it has a higher molecular weight (MW) than the limit of 600 Da typically applied in designing such compounds. On the basis of 2D NMR data, the compound is able to adopt a compact conformation. The dimensions, projection area, and dipole moment derived from this conformation are compatible with porin permeation, as are locations of polar groups upon superimposition to the crystal structure of ampicillin bound to E. coli OmpF porin. Minimum inhibitory concentration (MIC) shifts in a porin knock-out strain are also consistent with 1 predominately permeating through porins. In conclusion, we describe a carefully characterized case of a molecule outside default design parameters where MW does not adequately represent the 3D shape more directly related to permeability. Leveraging 3D design criteria would open up additional chemical space currently underutilized due to limitations perceived in 2D.


Subject(s)
Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Gram-Negative Bacteria/drug effects , Monobactams/chemistry , Monobactams/pharmacology , Escherichia coli/drug effects , Escherichia coli Proteins/drug effects , Hydrophobic and Hydrophilic Interactions , Microbial Sensitivity Tests , Models, Molecular , Molecular Conformation , Molecular Weight , Permeability , Porins
10.
PLoS One ; 14(9): e0221960, 2019.
Article in English | MEDLINE | ID: mdl-31498841

ABSTRACT

In Argentina, NDM metallo-ß-lactamase was first reported in 2013. By now, it has disseminated throughout the country in diverse Gram negative bacteria. Here, we report the case of a paediatric patient that underwent a 1-year hospitalisation due to erythrodermic psoriasis in 2014 and received multiple antimicrobial treatments. During his stay, five isolates were obtained from rectal swabs (rs) or blood culture (bc) suspicious of carbapenemase production: a K. quasipneumoniae subsp. quasipneumoniae (rs), Citrobacter freundii (rs), Escherichia coli (bc), Enterobacter cloacae (rs), and a Serratia marcescens (bc). The isolates were studied with broth microdilution, biparental conjugation and plasmid and whole genome sequencing (Illumina). All isolates harboured an 138,998-bp type 1 IncC plasmid that carried blaNDM-1, bleMBL, blaCMY-6, rmtC, aac(6')-Ib, and sul1 resistance genes. Additionally, the blaNDM-plasmids contained ISKpn8 an insertion sequence previously described as associated only to blaKPC. One isolate, a colistin-resistant E. coli, also carried a mcr-1-containing an IncI2 plasmid, which did not harbour additional resistance. The whole genome of K. quasipneumoniae subsp. quasipneumoniae isolate was fully sequenced. This isolate harboured, additionally to blaNDM, three plasmid-mediated quinolone resistance genes: qnrB4, qnrB52 and aac(6')-Ib-cr1. The E. cloacae isolate also harboured qnrA1. These findings alert to the underestimated horizontal dissemination of multidrug-resistant plasmids limiting treatment options with last resort antimicrobials.


Subject(s)
Enterobacteriaceae/genetics , Enterobacteriaceae/isolation & purification , Plasmids/genetics , Anti-Bacterial Agents/pharmacology , Child , Child, Preschool , Drug Resistance, Bacterial/genetics , Enterobacteriaceae/classification , Enterobacteriaceae/drug effects , Escherichia coli/genetics , Gene Transfer, Horizontal , Hospitals , Humans , Phylogeny , Psoriasis/microbiology
11.
ChemMedChem ; 14(16): 1560-1572, 2019 08 20.
Article in English | MEDLINE | ID: mdl-31283109

ABSTRACT

UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase (LpxC) is a Zn2+ deacetylase that is essential for the survival of most pathogenic Gram-negative bacteria. ACHN-975 (N-((S)-3-amino-1-(hydroxyamino)-3-methyl-1-oxobutan-2-yl)-4-(((1R,2R)-2-(hydroxymethyl)cyclopropyl)buta-1,3-diyn-1-yl)benzamide) was the first LpxC inhibitor to reach human clinical testing and was discovered to have a dose-limiting cardiovascular toxicity of transient hypotension without compensatory tachycardia. Herein we report the effort beyond ACHN-975 to discover LpxC inhibitors optimized for enzyme potency, antibacterial activity, pharmacokinetics, and cardiovascular safety. Based on its overall profile, compound 26 (LPXC-516, (S)-N-(2-(hydroxyamino)-1-(3-methoxy-1,1-dioxidothietan-3-yl)-2-oxoethyl)-4-(6-hydroxyhexa-1,3-diyn-1-yl)benzamide) was chosen for further development. A phosphate prodrug of 26 was developed that provided a solubility of >30 mg mL-1 for parenteral administration and conversion into the active drug with a t1/2 of approximately two minutes. Unexpectedly, and despite our optimization efforts, the prodrug of 26 still possesses a therapeutic window insufficient to support further clinical development.


Subject(s)
Amidohydrolases/antagonists & inhibitors , Anti-Bacterial Agents/pharmacology , Diynes/pharmacology , Enzyme Inhibitors/pharmacology , Heart/drug effects , Hydroxamic Acids/pharmacology , Animals , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/pharmacokinetics , Anti-Bacterial Agents/toxicity , Bacterial Proteins/antagonists & inhibitors , Cardiotoxicity , Diynes/chemical synthesis , Diynes/pharmacokinetics , Diynes/toxicity , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacokinetics , Enzyme Inhibitors/toxicity , Hydroxamic Acids/chemical synthesis , Hydroxamic Acids/pharmacokinetics , Hydroxamic Acids/toxicity , Male , Molecular Structure , Prodrugs/chemical synthesis , Prodrugs/pharmacokinetics , Prodrugs/pharmacology , Prodrugs/toxicity , Pseudomonas aeruginosa/drug effects , Rats, Sprague-Dawley , Structure-Activity Relationship
12.
J Chem Inf Model ; 59(5): 1709-1714, 2019 05 28.
Article in English | MEDLINE | ID: mdl-30943027

ABSTRACT

The success of hit-finding campaigns relies on many factors, including the quality and diversity of the set of compounds that is selected for screening. This paper presents a generalized workflow that guides compound selections from large compound archives with opportunities to bias the selections with available knowledge in order to improve hit quality while still effectively sampling the accessible chemical space. An optional flag in the workflow supports an explicit complement design function where diversity selections complement a given core set of compounds. Results from three project applications as well as a literature case study exemplify the effectiveness of the approach, which is available as a KNIME workflow named Biased Complement Diversity (BCD).


Subject(s)
Drug Discovery/methods , Animals , Anti-Bacterial Agents/pharmacology , Antimalarials/pharmacology , Drug Evaluation, Preclinical/methods , Gram-Negative Bacteria/drug effects , Gram-Negative Bacterial Infections/drug therapy , High-Throughput Screening Assays/methods , Humans , Malaria, Falciparum/drug therapy , Plasmodium falciparum/drug effects , Protein Interaction Maps/drug effects , Small Molecule Libraries/pharmacology , Workflow
13.
Mech Time Depend Mater ; 22(4): 421-433, 2018.
Article in English | MEDLINE | ID: mdl-30524189

ABSTRACT

A constitutive material law for linear thermo-viscoelasticity in the time domain is presented. The time-dependent relaxation formulation is given for full anisotropy, i.e., both the elastic and the viscous properties are anisotropic. Thereby, each element of the relaxation tensor is described by its own and independent Prony series expansion. Exceeding common viscoelasticity, time-dependent thermal expansion relaxation/creep is treated as inherent material behavior. The pertinent equations are derived and an incremental, implicit time integration scheme is presented. The developments are implemented into an implicit FEM software for orthotropic material symmetry under plane stress assumption. Even if this is a reduced problem, all essential features are present and allow for the entire verification and validation of the approach. Various simulations on isotropic and orthotropic problems are carried out to demonstrate the material behavior under investigation.

14.
Int Urol Nephrol ; 50(10): 1745-1751, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30132277

ABSTRACT

PURPOSE: Given that more cancers are being diagnosed earlier and that treatment of cancer is improving, health issues of cancer survivors are becoming more common and apparent. Pelvic radiation therapy for the treatment of gynecological cancers can lead to long-term collateral damage to the bladder, a condition termed radiation cystitis (RC). Late sequelae may take many years to develop and include incontinence and pain as well as hematuria. RC is a rare but potentially life-threatening condition for which there are few management and treatment options. METHODS: There are limited data in the literature regarding the effects of radiation on the bladder after gynecological cancer therapy and we hereby review the literature on cancer survivorship issues of pelvic radiation for gynecology literature. RESULTS: Treatment options are available for patients with radiation-induced hemorrhagic cystitis. However, most treatments are risky or only effective for a short timeframe and no therapy is currently available to reverse the disease progress. Furthermore, no standardized guidelines exist describing preferred management options. Common therapies include hyperbaric oxygen therapy, clot evacuation, fulguration, intravesical instillation of astringent agents, and surgery. Novel developing strategies include Botulinum Toxin injections and liposomal-tacrolimus instillations. These treatments and strategies are discussed. CONCLUSIONS: In this review, we will present current and advanced therapeutic strategies for RC to help cancer survivors deal with long-term bladder health issues.


Subject(s)
Cystitis/therapy , Genital Neoplasms, Female/radiotherapy , Hematuria/therapy , Radiation Injuries/therapy , Administration, Intravesical , Astringents/therapeutic use , Botulinum Toxins/therapeutic use , Cancer Survivors , Cystitis/etiology , Cystitis/surgery , Female , Hematuria/etiology , Hematuria/surgery , Humans , Hyperbaric Oxygenation , Immunosuppressive Agents/therapeutic use , Radiation Injuries/etiology , Radiation Injuries/surgery , Survivorship , Tacrolimus/therapeutic use , Urinary Bladder/radiation effects
15.
Urology ; 120: 180-186, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30059715

ABSTRACT

OBJECTIVE: To determine if the vascular damage in bladders of prostate cancer (PCa) survivors with radiation cystitis can be detected through altered angiogenic growth factors in urine. METHODS: Urine samples from PCa survivors with a history of external beam radiation therapy were tested for a panel of angiogenic growth factors by Luminex assay. Urine creatinine levels were measured through high performance liquid chromatography. Through a patient survey, data on patient demographics, radiation history, and urinary symptoms were collected. RESULTS: Hepatocyte growth factor (HGF), placental growth factor (PlGF), and vascular endothelial growth factor (VEGF) were altered in urine of PCa survivors with a history of radiation therapy. HGF and PlGF were elevated in response to irradiation, while VEGF had a decreasing trend. Within the irradiated population, HGF was also increased in patients diagnosed with radiation cystitis and patients with hematuria. PlGF and VEGF were only increased in the first year postirradiation, and VEGF was elevated in patients with hematuria. Finally, creatinine levels were increased in PCa survivors with a history of radiation therapy. CONCLUSION: Radiation cystitis is a debilitating bladder condition that cancer survivors are at risk of developing after pelvic radiation. In this study, we identified 3 pro-angiogenic factors that may be urine biomarkers and, if validated in future studies, could indicate new strategy approaches to treat radiation cystitis.


Subject(s)
Cystitis/etiology , Hepatocyte Growth Factor/urine , Placenta Growth Factor/urine , Radiotherapy/adverse effects , Vascular Endothelial Growth Factor A/urine , Aged , Biomarkers/urine , Cancer Survivors , Case-Control Studies , Creatinine/urine , Cystitis/urine , Hematuria/etiology , Humans , Male , Prostatic Neoplasms/radiotherapy
16.
Bioorg Med Chem Lett ; 28(4): 748-755, 2018 02 15.
Article in English | MEDLINE | ID: mdl-29336873

ABSTRACT

Metallo-ß-lactamases (MBLs), such as New Delhi metallo-ß-lactamase (NDM-1) have spread world-wide and present a serious threat. Expression of MBLs confers resistance in Gram-negative bacteria to all classes of ß-lactam antibiotics, with the exception of monobactams, which are intrinsically stable to MBLs. However, existing first generation monobactam drugs like aztreonam have limited clinical utility against MBL-expressing strains because they are impacted by serine ß-lactamases (SBLs), which are often co-expressed in clinical isolates. Here, we optimized novel monobactams for stability against SBLs, which led to the identification of LYS228 (compound 31). LYS228 is potent in the presence of all classes of ß-lactamases and shows potent activity against carbapenem-resistant isolates of Enterobacteriaceae (CRE).


Subject(s)
Anti-Bacterial Agents/pharmacology , Bacterial Proteins/metabolism , Carbapenem-Resistant Enterobacteriaceae/drug effects , Monobactams/pharmacology , beta-Lactam Resistance/drug effects , beta-Lactamases/metabolism , Animals , Anti-Bacterial Agents/adverse effects , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/metabolism , Aztreonam/pharmacology , CHO Cells , Cricetulus , Drug Stability , Escherichia coli/drug effects , Female , Humans , Meropenem , Mice , Microbial Sensitivity Tests , Molecular Structure , Monobactams/adverse effects , Monobactams/chemistry , Monobactams/metabolism , Pseudomonas aeruginosa/drug effects , Receptors, GABA-A/metabolism , Seizures/chemically induced , Structure-Activity Relationship , Thienamycins/pharmacology
18.
ChemMedChem ; 12(20): 1687-1692, 2017 10 20.
Article in English | MEDLINE | ID: mdl-28881459

ABSTRACT

Conformationally constrained tetracyclic fluoroquinolones (FQs) were synthesized and profiled for their microbiological spectrum. The installation of a seven-membered ring between the pyrrolidine substituents and the C8 position on the FQ core scaffold resulted in a remarkable enhancement of microbiological potency toward both Gram-positive and Gram-negative bacteria. Focused optimization of seven-membered ring composition, stereochemistry, and amine placement led to the discovery of the two lead compounds that were selected for further progression.


Subject(s)
Fluoroquinolones/chemical synthesis , Fluoroquinolones/pharmacology , Tetracyclines/chemical synthesis , Tetracyclines/pharmacology , Acinetobacter baumannii/drug effects , Microbial Sensitivity Tests , Molecular Structure , Pseudomonas aeruginosa/drug effects , Structure-Activity Relationship
19.
Open Biol ; 6(9)2016 Sep.
Article in English | MEDLINE | ID: mdl-27655731

ABSTRACT

As part of a programme of synthesizing and investigating the biological properties of new fluoroquinolone antibacterials and their targeting of topoisomerase IV from Streptococcus pneumoniae, we have solved the X-ray structure of the complexes of two new 7,8-bridged fluoroquinolones (with restricted C7 group rotation favouring tight binding) in complex with the topoisomerase IV from S. pneumoniae and an 18-base-pair DNA binding site-the E-site-found by our DNA mapping studies to bind drug strongly in the presence of topoisomerase IV (Leo et al. 2005 J. Biol. Chem. 280, 14 252-14 263, doi:10.1074/jbc.M500156200). Although the degree of antibiotic resistance towards fluoroquinolones is much lower than that of ß-lactams and a range of ribosome-bound antibiotics, there is a pressing need to increase the diversity of members of this successful clinically used class of drugs. The quinolone moiety of the new 7,8-bridged agents ACHN-245 and ACHN-454 binds similarly to that of clinafloxocin, levofloxacin, moxifloxacin and trovofloxacin but the cyclic scaffold offers the possibility of chemical modification to produce interactions with other topoisomerase residues at the active site.

20.
Chem Biodivers ; 12(2): 179-93, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25676502

ABSTRACT

ß(3) -Octaarginine chains were attached to the functional groups NH and CO2 H of the antibacterial fluoroquinolones ciprofloxacin (→1) and enrofloxacin (→2), respectively, in order to find out whether the activity increases by attachment of the polycationic, cell-penetrating peptide (CPP) moiety. For comparison, simple amides, 3-5, of the two antimicrobial compounds and ß(3) -octaarginine amide (ßR8 ) were included in the antibacterial susceptibility tests to clarify the impact of chemical modification on the microbiological activity of either scaffold (Table).


Subject(s)
Anti-Bacterial Agents/chemistry , Cell-Penetrating Peptides/chemistry , Ciprofloxacin/chemistry , Fluoroquinolones/chemistry , Oligopeptides/chemistry , Anti-Bacterial Agents/metabolism , Anti-Bacterial Agents/pharmacology , Binding Sites , Ciprofloxacin/metabolism , Ciprofloxacin/pharmacology , DNA Gyrase/chemistry , DNA Gyrase/metabolism , Enrofloxacin , Fluoroquinolones/metabolism , Fluoroquinolones/pharmacology , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Microbial Sensitivity Tests , Molecular Docking Simulation , Protein Structure, Tertiary , Structure-Activity Relationship
SELECTION OF CITATIONS
SEARCH DETAIL
...