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Dolna M, Nowacki M, Danylyuk O, Brotons-Rufes A, Poater A, Michalak M. NHC-BIAN-Cu(I)-Catalyzed Friedländer-Type Annulation of 2-Amino-3-(per)fluoroacetylpyridines with Alkynes on Water. J Org Chem 2022; 87:6115-6136. [PMID: 35394784 PMCID: PMC9087358 DOI: 10.1021/acs.joc.2c00380] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
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The direct catalytic
alkynylation/dehydrative cyclization of 2-amino-3-trifluoroacetyl-pyridines
on water was developed for the efficient synthesis of a broad range
of fluorinated 1,8-naphthyridines from terminal alkynes. A novel N-heterocyclic
carbene (NHC) ligand system that combines a π-extended acenaphthylene
backbone with sterically bulky pentiptycene pendant groups was successfully
utilized in a copper- or silver-mediated cyclization. Computational
analysis of the reaction pathway supports our explanation of the different
experimental conversions and yields for the set of copper and silver
catalysts. The impact of steric hindrance at the metal center and
the flexibility of substituents on the imidazole ring of the NHC on
catalytic performance are also discussed.
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Affiliation(s)
- Magdalena Dolna
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Michał Nowacki
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Oksana Danylyuk
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Artur Brotons-Rufes
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, c/ M. Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain
| | - Albert Poater
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, c/ M. Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain
| | - Michał Michalak
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
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2
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Kaur R, Rani P, Atanasov AG, Alzahrani Q, Gupta R, Kapoor B, Gulati M, Chawla P. Discovery and Development of Antibacterial Agents: Fortuitous and Designed. Mini Rev Med Chem 2021; 22:984-1029. [PMID: 34939541 DOI: 10.2174/1570193x19666211221150119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 10/18/2021] [Accepted: 10/25/2021] [Indexed: 11/22/2022]
Abstract
Today, antibacterial drug resistance has turned into a significant public health issue. Repeated intake, suboptimal and/or unnecessary use of antibiotics, and, additionally, the transfer of resistance genes are the critical elements that make microorganisms resistant to conventional antibiotics. A substantial number of antibacterials that were successfully utilized earlier for prophylaxis and therapeutic purposes have been rendered inadequate due to this phenomenon. Therefore, the exploration of new molecules has become a continuous endeavour. Many such molecules are at various stages of investigation. A surprisingly high number of new molecules are currently in the stage of phase 3 clinical trials. A few new agents have been commercialized in the last decade. These include solithromycin, plazomicin, lefamulin, omadacycline, eravacycline, delafloxacin, zabofloxacin, finafloxacin, nemonoxacin, gepotidacin, zoliflodacin, cefiderocol, BAL30072, avycaz, zerbaxa, vabomere, relebactam, tedizolid, cadazolid, sutezolid, triclosan and afabiacin. This article aims to review the investigational and recently approved antibacterials with a focus on their structure, mechanisms of action/resistance, and spectrum of activity. Delving deep, their success or otherwise in various phases of clinical trials is also discussed while attributing the same to various causal factors.
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Affiliation(s)
- Ravleen Kaur
- Department of Health Sciences, Cape Breton University, Sydney, Nova Scotia. Canada
| | - Pooja Rani
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara. India
| | - Atanas G Atanasov
- Ludwig Boltzmann Institute of Digital Health and Patient Safety, Medical University of Vienna, Vienna. Austria
| | - Qushmua Alzahrani
- Department of Pharmacy/Nursing/Medicine Health and Environment, University of the Region of Joinville (UNIVILLE) volunteer researcher, Joinville. Brazil
| | - Reena Gupta
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara . India
| | - Bhupinder Kapoor
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara . India
| | - Monica Gulati
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara . India
| | - Pooja Chawla
- Department of Pharmaceutical Chemistry and Analysis, ISF College of Pharmacy, Ghal Kalan Moga, Punjab 142001. India
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3
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Jiang S, Yang Z, Guo Z, Li Y, Chen L, Zhu Z, Chen X. Transition metal-free α-methylation of 1,8-naphthyridine derivatives using DMSO as methylation reagent. Org Biomol Chem 2019; 17:7416-7424. [PMID: 31359026 DOI: 10.1039/c9ob01490j] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A practical approach to the direct α-methylation of 1,8-naphthyridines under mild reaction conditions has been developed using simple and readily available DMSO as a convenient and environmentally friendly carbon source. This method is transition metal-free and highly chemoselective, shows good functional group tolerance, and uses DMSO as a methyl source, providing efficient and rapid access to an important compound class, 2-methyl-1,8-naphthyridines.
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Affiliation(s)
- Shaohua Jiang
- School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529020, China.
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4
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Wagdy HA, Tarek M, Amer A, Gamal M, Elmazar M. A Validated Reverse Phase-Ultra-Performance Liquid Chromatography Method for the Determination of Gemifloxacin Mesylate in Bulk and its Pharmaceutical Preparation. Turk J Pharm Sci 2019; 16:8-13. [PMID: 32454688 DOI: 10.4274/tjps.04934] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 11/30/2017] [Indexed: 12/01/2022]
Abstract
Objectives Gemifloxacin Mesylate is a fourth generation fluoroquinolone antibacterial agent. A simple, accurate, and precise reversed phase (RP)-ultra performance liquid chromatography (UPLC) method was developed and validated for short time analysis of Gemifloxacin Mesylate in its bulk and pharmaceutical preparation. Materials and Methods The optimum separation was achieved at 0.5±0.03 min using an AcclaimTM RSLC 120 C18 column 2.2 μm (2.1×100 mm) at 30°C by isocratic mobile phase at pH 3.0 composed of acetonitrile:phosphate buffer (25 mM) in a ratio of 75:25 (v/v). The column effluents were monitored at 276 nm using a photodiode array detector at a flow rate of 0.5 mL/min. The method was validated according to International Conference on Harmonization guidelines. Results The linearity of the calibration curve ranged from 0.5 μg/mL to 10 μg/mL and the square of the regression coefficient (r2) was 0.9991. The % relative standard deviation (RSD) of inter-day precision ranged from 0.081% to 1.233%, while for intra-day it ranged from 0.364% to 1.018%. The method was accurate with % recovery ranging from 93.71% to 100.29% and % RSD ranging from 1.054 to 2.722. The limit of detection and the limit of quantification were 0.066 and 0.2 μg/mL, respectively. Conclusion The validated method proved its ability for the assay of Gemifloxacin Mesylate in its bulk and dosage form in a short time (less than 1 min). To the best of our knowledge, this is the first RP-UPLC method for the determination of Gemifloxacin Mesylate.
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Affiliation(s)
- Hebatallah A Wagdy
- The British University in Egypt, Faculty of Pharmacy, Department of Pharmaceutical Analytical Chemistry, Cairo, Egypt.,The British University in Egypt, Faculty of Pharmacy, The Center for Drug Research and Development, Cairo, Egypt
| | - Mohamed Tarek
- The British University in Egypt, Faculty of Pharmacy, Department of Pharmaceutical Analytical Chemistry, Cairo, Egypt.,The British University in Egypt, Faculty of Pharmacy, The Center for Drug Research and Development, Cairo, Egypt
| | - Ahmed Amer
- The British University in Egypt, Faculty of Pharmacy, The Center for Drug Research and Development, Cairo, Egypt
| | - Menna Gamal
- The British University in Egypt, Faculty of Pharmacy, The Center for Drug Research and Development, Cairo, Egypt
| | - Mohey Elmazar
- The British University in Egypt, Faculty of Pharmacy, The Center for Drug Research and Development, Cairo, Egypt.,The British University in Egypt, Faculty of Pharmacy, Department of Pharmacology and Toxicology, Cairo, Egypt
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Mousavi SHH. Determination of Gemifloxacin in human plasma by high performance liquid chromatography using Ultra Violet detector and its application to a bioequivalence study. BRAZ J PHARM SCI 2018. [DOI: 10.1590/s2175-97902018000417239] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Oh SH, Park HS, Kim HS, Yun JY, Oh K, Cho YL, Kwak JH. Antimicrobial activities of LCB10-0200, a novel siderophore cephalosporin, against the clinical isolates of Pseudomonas aeruginosa and other pathogens. Int J Antimicrob Agents 2017; 50:700-706. [PMID: 28668680 DOI: 10.1016/j.ijantimicag.2017.06.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 06/01/2017] [Accepted: 06/05/2017] [Indexed: 01/16/2023]
Abstract
Infections caused by multidrug-resistant bacteria, including Pseudomonas aeruginosa, are threatening public health worldwide. Therefore, a novel antibacterial agent is needed to treat these infections. Here, we investigated the in vitro and in vivo activities of a novel siderophore-conjugated cephalosporin, LCB10-0200, against the clinical isolates of Gram-negative bacteria, including multidrug-resistant P. aeruginosa. In vitro susceptibility to LCB10-0200 was assessed by performing a two-fold agar dilution method, as described by the Clinical and Laboratory Standards Institute. LCB10-0200 showed the most potent antibacterial activity against P. aeruginosa clinical isolates, including β-lactamase-producing strains. Moreover, LCB10-0200 showed better antibacterial activity against recently isolated clinical isolates than its comparators, except colistin. The in vivo activity of LCB10-0200 was examined using four mouse models of systemic, thigh, respiratory tract, and urinary tract infections. LCB10-0200 was more effective than ceftazidime in treating systemic, thigh, respiratory tract, and urinary tract infections caused by drug-susceptible and drug-resistant P. aeruginosa strains in these mouse models. Thus, the potent in vitro and in vivo activities of LCB10-0200 observed in the present study indicate that it has the potential for treating infections caused by Gram-negative bacteria, including P. aeruginosa.
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Affiliation(s)
- Sang-Hun Oh
- School of Life Science, Handong Global University, Pohang, Republic of Korea
| | - Hee-Soo Park
- School of Food Science and Biotechnology, Institute of Agricultural Science and Technology, Kyungpook National University, Daegu, Republic of Korea
| | - Hye-Shin Kim
- School of Life Science, Handong Global University, Pohang, Republic of Korea
| | | | - Kyuman Oh
- LegoChem BioScience Inc., Daejeon, South Korea
| | | | - Jin-Hwan Kwak
- School of Life Science, Handong Global University, Pohang, Republic of Korea.
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7
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Sadeek SA, Abd El-Hamid SM, El-Aasser MM. Synthesis, characterization, antimicrobial and cytotoxicity studies of some transition metal complexes with gemifloxacin. MONATSHEFTE FUR CHEMIE 2015. [DOI: 10.1007/s00706-015-1507-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Sagirli O, Demirci S, Önal A. A very simple high-performance liquid chromatographic method with fluorescence detection for the determination of gemifloxacin in human breast milk. LUMINESCENCE 2015; 30:1326-9. [DOI: 10.1002/bio.2901] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Revised: 02/04/2015] [Accepted: 02/14/2015] [Indexed: 11/08/2022]
Affiliation(s)
- Olcay Sagirli
- Istanbul University; Faculty of Pharmacy, Department of Analytical Chemistry; 34116 Beyazit, Istanbul Turkey
| | - Seda Demirci
- Istanbul University; Faculty of Pharmacy, Department of Analytical Chemistry; 34116 Beyazit, Istanbul Turkey
| | - Armağan Önal
- Istanbul University; Faculty of Pharmacy, Department of Analytical Chemistry; 34116 Beyazit, Istanbul Turkey
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Nazar MF, Mukhtar F, Chaudry S, Ashfaq M, Mehmood S, Asif A, Rana UA. Biophysical probing of antibacterial Gemifloxacin assimilated in surfactant mediated molecular assemblies. J Mol Liq 2014. [DOI: 10.1016/j.molliq.2014.11.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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10
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Two validated spectrofluorometric methods for determination of gemifloxacin mesylate in tablets and human plasma. Int J Anal Chem 2013; 2013:137279. [PMID: 23762060 PMCID: PMC3670531 DOI: 10.1155/2013/137279] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 04/16/2013] [Accepted: 04/16/2013] [Indexed: 11/18/2022] Open
Abstract
Two new, sensitive, and selective spectrofluorometric methods were developed for the determination of gemifloxacin mesylate (GFX) in tablets and spiked human plasma. Method A was based on measurement of the enhanced fluorescence spectral behaviour of GFX in a sodium dodecyl sulphate (SDS) micellar system. In aqueous solution of acetate buffer pH 5.5, the fluorescence intensity of GFX was greatly enhanced about tenfold in the presence of SDS. The fluorescence intensity was measured at 402 nm after excitation at 274 nm. Method B was based on Hantzsch condensation reaction between the primary amino group of GFX with acetylacetone and formaldehyde in acetate buffer of pH 3.5 yielding a highly yellow fluorescent derivative. The reaction of GFX with acetylacetone-formaldehyde system solution resulted in bathochromic shift of both emission (476 nm) and excitation (420 nm) wavelengths. The fluorescence intensity was directly proportional to the concentration over the range 10–1000 ng/ml and 100–2000 ng/ml for method A and B, respectively. The proposed methods were applied successfully for determination of GFX in its tablets and spiked plasma. Therefore, these methods can be considered of real interest for reliable and practical quality control analysis of GFX.
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High Throughput Quantitative Bioanalytical LC/MS/MS Determination of Gemifloxacin in Human Urine. J CHEM-NY 2013. [DOI: 10.1155/2013/905704] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
A highly specific, sensitive, and rapid method, to quantify gemifloxacin in human urine using HPLC coupled to the triple quadrupole mass spectrometer system, was developed and validated. Gemifloxacin and ofloxacin (internal standard) were rapidly extracted from urine samples without any tedious pretreatment procedure. Urine samples were filtered through a Millex-GP, 0.22 μm syringe filter. Optimal chromatographic separation of the analytes was achieved on Zorbax SB-C18(30 mm × 2 mm i.d., 3.5 μm maintained at ambient temperature). The mobile phase consisted of 0.1% formic acid (pH 3.2) and acetonitrile (80 : 20) and a flow rate of 0.2 mL min−1for 4 min. The analytes were monitored by electrospray ionization in positive ion multiple reaction monitoring mode. The method provided a linear response (r=0.9998) from a quantitation range of 5 ng mL−1to at least 500 ng mL−1. The mean extraction recovery % of gemifloxacin from spiked human urine was 101.33 ± 2.58%. The reproducibility of the method was reliable with the intra- and inter-day precision of <2% and accuracy within 2%. The established method was reliably applied for the determination of gemifloxacin in volunteers’ urine samples with the mean recoveries of gemifloxacin from Factive tablets 320 mg > 97.0%.
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Predicting the exposure and antibacterial activity of fluoroquinolones based on physicochemical properties. Eur J Pharm Sci 2012; 47:21-7. [DOI: 10.1016/j.ejps.2012.04.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Revised: 03/19/2012] [Accepted: 04/27/2012] [Indexed: 11/18/2022]
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Abstract
Introduction: The main objective was to develop and validate a simple, accurate, precise, and sensitive ion-pair spectrophotometric extraction method for the assay of gemifloxacin mesylate (GFX) in pure, tablets and spiked human urine. Materials and Methods: The method is based upon the reaction of gemifloxacin with methyl orange, forming a yellow-colored complex in acidic medium, which is extracted in chloroform and analyzed. The extracted complexes showed absorbance maxima (λmax) found to be at 427 nm. Results: Beer's law was obeyed for a wide concentration range, i.e., 10–80 μg/ mL as the extracted species seemed well defined and stable. The surface or an interphase adsorption phenomenon was not a problem. Optimization of the reaction was carried out with factors such as buffer strength, stability of complex, and molar ratio of drug: Dye and extraction time. The proposed method was validated as per the ICH guidelines. The recovery studies confirmed the accuracy and precision of the method. Conclusion: The above-mentioned method was a rapid tool for routine analysis of GFX in the bulk and pharmaceutical dosage forms.
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Sultana N, Arayne MS, Shamim S, Naz A. Validated Method for the Simultaneous Determination of Gemifloxacin and H 2‐receptor Antagonists in Bulk, Pharmaceutical Formulations and Human Serum by RP‐HPLC; In‐vitro Applications. J CHIN CHEM SOC-TAIP 2011; 58:629-636. [DOI: 10.1002/jccs.201190098] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024]
Abstract
AbstractSimple, isocratic and rapid RP‐HPLC method has been developed for the simultaneous analysis of gemifloxacin and H2‐receptor antagonists i.e. Cimetidine, Famotidine and Ranitidine, in bulk, pharmaceutical formulation and human serum. Separation was achieved on the RP‐Mediterranea column [C18 (250 × 4.6 mm, 5 μ)] at ambient temperature using mobile phase consisting of acetonitrile: methanol: water (20:28:52 v/v/v pH 2.8 adjusted by phosphoric acid). Flow rate was 1.0 mL/min with an average operating pressure of 180 kg/cm2. Gatifloxacin (GATI) was used as an internal standard (IS). Quantitation was achieved with UV detection at 221, 256 and 267 nm, respectively. Linear calibration curves, at concentration ranges of 0.05‐37.5 μgmL‐L with a correlation coefficient of ±0.9994. The detection and quantification limits were in the ranges of 0.023‐0.250 μgmL‐L and 0.071‐0.756 μgmL‐L, respectively. Friedman's and Student's t‐test were applied to correlate these results. Method was validated in terms of selectivity, linearity, precision, robustness, recovery, limits of detection and quantitation and is applicable to the routine analysis of GFX and H2‐receptor antagonists, alone or in combination.
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Differential effect of P-gp and MRP2 on cellular translocation of gemifloxacin. Int J Pharm 2011; 420:26-33. [PMID: 21864659 DOI: 10.1016/j.ijpharm.2011.08.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 07/14/2011] [Accepted: 08/08/2011] [Indexed: 02/07/2023]
Abstract
Fluoroquinolones are broad spectrum antibiotics widely indicated in the treatment of both human and animal diseases. The primary objective of this study was to assess short and long term affinities of gemifloxacin towards efflux transporters (P-gp, MRP2) and nuclear hormone receptor (PXR). Uptake and dose dependent inhibition studies were performed with [(14)C] erythromycin (0.25 μCi/ml) on MDCKII-MDR1 and MDCKII-MRP2 cells. Cellular accumulation of calcein-AM was further determined to confirm the affinity of gemifloxacin towards P-gp and MRP2. Transport studies were conducted to determine bi-directional permeability and to assess efflux ratio of gemifloxacin. LS-180 cells were treated with three different concentrations of gemifloxacin for 72 h and real-time PCR analysis was performed to study the quantitative gene expression levels of PXR, MDR1 and MRP2. Further, [(14)C] erythromycin uptake was also performed on LS-180 treated cells to better delineate the functional activity of efflux transporters. Results from our study suggest that gemifloxacin may be a substrate of both the efflux transporters studied. This compound inhibited both P-gp and MRP2 mediated efflux of [(14)C] erythromycin in a dose dependent manner with IC(50) values of 123 ± 2 μM and 16 ± 2 μM, respectively. The efflux ratio of [(14)C] erythromycin lowered from 3.56 to 1.63 on MDCKII-MDR1 cells and 4.93 to 1.26 on MDCKII-MRP2 cells. This significant reduction in efflux ratio further confirmed the substrate specificity of gemifloxacin towards P-gp and MRP2. Long term exposure significantly induced the expression of PXR (18 fold), MDR1 (6 fold) and MRP2 (6 fold). A decrease (20%) in [(14)C] erythromycin uptake further confirmed the elevated functional activity of P-gp and MRP2. In conclusion, our studies demonstrated that gemifloxacin is effluxed by both P-gp and MRP2. Long term exposure induced their gene expression and functional activity. This substrate specificity of gemifloxacin towards these efflux transporters may be one of the major factors accounting for low oral bioavailability (71%). Better understanding of these mechanistic interactions may aid in the development of newer strategies to achieve adequate therapeutic levels and higher bioavailability.
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Vallet CM, Marquez B, Ngabirano E, Lemaire S, Mingeot-Leclercq MP, Tulkens PM, Van Bambeke F. Cellular accumulation of fluoroquinolones is not predictive of their intracellular activity: studies with gemifloxacin, moxifloxacin and ciprofloxacin in a pharmacokinetic/pharmacodynamic model of uninfected and infected macrophages. Int J Antimicrob Agents 2011; 38:249-56. [PMID: 21764262 DOI: 10.1016/j.ijantimicag.2011.05.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 05/14/2011] [Accepted: 05/17/2011] [Indexed: 10/17/2022]
Abstract
Fluoroquinolones enter eukaryotic cells but the correlation between cellular accumulation and activity remains poorly established. Gemifloxacin is known to accumulate to a larger extent than most other fluoroquinolones in tissues. Using murine J774 macrophages and human THP-1 monocytes, we show that gemifloxacin accumulates more than ciprofloxacin and even moxifloxacin. Whilst showing indistinguishable kinetics of accumulation in J774 macrophages, gemifloxacin was released at an approximately two-fold slower rate than ciprofloxacin and its release was only partial. Gemifloxacin was also a weaker substrate than ciprofloxacin for the efflux transporter Mrp4 active in J774 macrophages. In cells infected with Listeria monocytogenes or Staphylococcus aureus (typical cytoplasmic and phagolysosomal organisms, respectively), gemifloxacin was equipotent to moxifloxacin and ciprofloxacin in concentration-dependent experiments if data are normalised based on the minimum inhibitory concentration (MIC) in broth. Thus, larger cellular concentrations of gemifloxacin than of moxifloxacin or ciprofloxacin were needed to obtain a similar target effect. Fractionation studies showed a similar subcellular distribution for all three fluoroquinolones, with approximately two-thirds of the cell-associated drug recovered in the soluble fraction (cytosol). These data suggest that cellular accumulation of fluoroquinolones is largely a self-defeating process as far as activity is concerned, with the intracellular drug made inactive in proportion to its accumulation level. Whilst these observations do not decrease the intrinsic value of fluoroquinolones for the treatment of intracellular infections, they indicate that ranking fluoroquinolones based on cell accumulation data without measuring the corresponding intracellular activity may lead to incorrect conclusions regarding their real potential.
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Affiliation(s)
- Coralie M Vallet
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Avenue E. Mounier 73 bte B1.73.05, B-1200 Brussels, Belgium
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Sharif S, Khan IU, Sheikh TA, Sharif Y, Ashfaq M. Validated stability-indicating HPLC method for analysis of gemifloxacin in tablet formulations. ACTA CHROMATOGR 2011. [DOI: 10.1556/achrom.23.2011.1.6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Al-Hadiya BM, Khady AA, Mostafa GA. Validated liquid chromatographic-fluorescence method for the quantitation of gemifloxacin in human plasma. Talanta 2010; 83:110-6. [DOI: 10.1016/j.talanta.2010.08.047] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 08/26/2010] [Accepted: 08/26/2010] [Indexed: 10/19/2022]
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Choi HJ, Cho HS, Han SC, Hyun MH. HPLC of fluoroquinolone antibacterials using chiral stationary phase based on enantiomeric (3,3′-diphenyl-1,1′-binaphthyl)-20-crown-6. J Sep Sci 2009; 32:536-41. [DOI: 10.1002/jssc.200800610] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Park HS, Yoon YM, Jung SJ, Kim CM, Kim JM, Kwak JH. Antistaphylococcal activities of CG400549, a new bacterial enoyl-acyl carrier protein reductase (FabI) inhibitor. J Antimicrob Chemother 2007; 60:568-74. [PMID: 17606482 DOI: 10.1093/jac/dkm236] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES This study was performed to analyse in vitro and in vivo activities of CG400549, a new FabI inhibitor, against clinical isolates of staphylococci. The mode of action of CG400549 and resistance mechanism of Staphylococcus aureus against CG400549 were also investigated by genetic approaches. METHODS In vitro activity of CG400549 was evaluated by the 2-fold agar sdilution method as described by the CLSI, and compared with those of oxacillin, erythromycin, ciprofloxacin, sparfloxacin, moxifloxacin, gemifloxacin, vancomycin, linezolid and quinupristin-dalfopristin. In vivo activity of CG400549 was determined against systemic infections in mice. Time-kill curves of CG400549 were analysed at concentrations of 1 x , 2 x and 4 x MIC against S. aureus strains. RESULTS CG400549 had the lowest MICs among the test compounds against 238 clinical isolates of S. aureus (MIC90, 0.25 mg/L) and 51 clinical isolates of coagulase-negative staphylococci (MIC90, 1 mg/L). The activity of CG400549 was irrespective of whether the strains were methicillin-susceptible or -resistant. Furthermore, CG400549 was effective by oral or subcutaneous administration against systemic infections in mice. In a time-kill study, CG400549 at concentrations of 1 x MIC, 2 x MIC and 4 x MIC had a bacteriostatic activity during 24 h. A FabI-overexpressing S. aureus strain gave rise to an increase in the MIC of CG400549 compared with the parental strain, while the susceptibilities of the FabI-overexpressing S. aureus strain to the other antibacterial agents such as oxacillin, erythromycin and ciprofloxacin were not affected. This result showed that the mode of action of CG400549 was via inhibition of FabI, which is involved in biosynthesis of fatty acids in bacteria. Study of the resistance mechanism of S. aureus showed that CG400549-resistant mutants of S. aureus had an alteration in FabI at Phe-204 to Leu. CONCLUSIONS CG400549 had potent in vitro and in vivo activity against staphylococci, including methicillin-, ciprofloxacin- and multidrug-resistant staphylococci strains. This compound could be a good candidate for clinical development as a novel anti-MRSA drug.
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Affiliation(s)
- Hee Soo Park
- School of Life and Food Sciences, Handong Global University, Pohang 791-708, South Korea
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Park HS, Kim HJ, Seol MJ, Choi DR, Choi EC, Kwak JH. In vitro and in vivo antibacterial activities of DW-224a, a new fluoronaphthyridone. Antimicrob Agents Chemother 2006; 50:2261-4. [PMID: 16723601 PMCID: PMC1479124 DOI: 10.1128/aac.01407-05] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
DW-224a showed the most potent in vitro activity among the quinolone compounds tested against clinical isolates of gram-positive bacteria. Against gram-negative bacteria, DW-224a was slightly less active than the other fluoroquinolones. The in vivo activities of DW-224a against gram-positive bacteria were more potent than those of other quinolones.
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Affiliation(s)
- Hee-Soo Park
- School of Life and Food Sciences, Handong Global University, Kyungbuk, Republic of Korea
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22
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Bae CS, Oh DM, Bae JG, Kim JC, Kim SH, Kim SG, Jeong MJ, Kim YS, Lim SC. Ultrastructural changes of the gemifloxacin on Achilles tendon in immature rats: comparison with those of ciproxacin and ofloxacin. Basic Clin Pharmacol Toxicol 2006; 98:406-10. [PMID: 16623866 DOI: 10.1111/j.1742-7843.2006.pto_326.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Gemifloxacin is a synthetic fluoroquinolone antimicrobial agent that exhibits potent activity against most Gram-negative and Gram-positive organisms, and has a comparatively low chondrotoxic potential in immature animals. This study examined the effects of gemifloxacin on the Achilles tendons in immature Sprague-Dawley rats treated by oral intubation once daily for 5 consecutive days from postnatal week 4 onward at doses of 0 (vehicle), and 600 mg/kg body weight. Ofloxacin or ciprofloxacin were used for comparison. The Achilles tendon specimens were examined by electron microscopy. In comparison with the vehicle-treated controls, there were ultrastructural changes in all samples from the gemifloxacin-, ofloxacin-, and ciprofloxacin-treated rats. Degenerative changes were observed in the tenocytes, and the cells that detached from the extracellular matrix were recognizable. The degree of degenerative changes and the number of degenerated cells in the Achilles tendon were significantly higher in the treated group than in the control group. Moreover, among the quinolone-treated groups, these findings were most significant in the ofloxacin-treated group, and least significant in the gemifloxacin-treated group. It is unclear what these findings mean with respect to the possible risk in juvenile patients treated with gemifloxacin or other quinolones. However, these results show that gemifloxacin causes less changes in the connective tissue structures.
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Affiliation(s)
- Chun-Sik Bae
- College of Veterinary Medicine, Biotechnology Research Institute, Chonnam National University, Gwangju 500-757, Korea
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Bhavnani SM, Andes DR. Gemifloxacin for the treatment of respiratory tract infections: in vitro susceptibility, pharmacokinetics and pharmacodynamics, clinical efficacy, and safety. Pharmacotherapy 2005; 25:717-40. [PMID: 15899734 DOI: 10.1592/phco.25.5.717.63583] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Gemifloxacin is a synthetic fluoroquinolone antimicrobial agent exhibiting potent activity against most gram-negative and gram-positive organisms, such as the important community-acquired respiratory pathogens Streptococcus pneumoniae (including multidrug-resistant S. pneumoniae), Haemophilus influenzae , and Moraxella catarrhalis . The agent's mechanism of action involves dual targeting of two essential bacterial enzymes: DNA gyrase and topoisomerase IV. Gemifloxacin was approved by the Food and Drug Administration in April 2003 for treatment of community-acquired pneumonia and acute bacterial exacerbation of chronic bronchitis. The drug has an oral bioavailability of approximately 71%. Approximately 20-35% of gemifloxacin is excreted unchanged in the urine after 24 hours. The elimination half-life of gemifloxacin is 6-8 hours in patients with normal renal function, supporting once-daily dosing. The 24-hour free-drug area under the plasma concentration-time curve:minimum inhibitory concentration ratio (fAUC(0-24):MIC) associated with efficacy, based on results from in vitro and animal models of infection, is approximately 30. With a mean fAUC(0-24) of approximately 3 microg*hour/ml (35% of total AUC(0-24) of 8.4) and a median S. pneumoniae MIC for 90% of tested strains of 0.03, a fAUC(0-24):MIC ratio of 100 would be expected after standard dosing (320 mg once/day). In clinical studies involving both hospitalized and outpatient populations, gemifloxacin has been highly effective in the treatment of community-acquired pneumonia and acute exacerbation of chronic bronchitis. Clinical success rates ranged from 93.9-95.9% in patients with community-acquired pneumonia and 96.1-97.5% in those with acute exacerbation of chronic bronchitis. Gemifloxacin is well tolerated; the frequency of adverse events with this agent is low. Most adverse events are mild-to-moderate in severity, with diarrhea (< 4%), nausea and rash (< 3%), and headache (< 2%) most commonly reported. Drug interactions with gemifloxacin are not common, although absorption is greatly reduced when given with divalent and trivalent cation-containing compounds, such as antacids. Due to its potent activity against many common gram-positive and gram-negative respiratory pathogens, its proven clinical efficacy, and its favorable safety profile, gemifloxacin is a highly effective empiric treatment for community-acquired lower respiratory tract infections.
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Affiliation(s)
- Sujata M Bhavnani
- Institute for Clinical Pharmacodynamics, Ordway Research Institute, Albany, NY 12208, USA.
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24
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Abstract
Quinolones are one of the largest classes of antimicrobial agents used worldwide. This review considers the quinolones that are available currently and used widely in Europe (norfoxacin, ciprofloxacin, ofloxacin, levofloxacin and moxifloxacin) within their historical perspective, while trying to position them in the context of recent and possible future advances based on an understanding of: (1) their chemical structures and how these impact on activity and toxicity; (2) resistance mechanisms (mutations in target genes, efflux pumps); (3) their pharmacodynamic properties (AUC/MIC and Cmax/MIC ratios; mutant prevention concentration and mutant selection window); and (4) epidemiological considerations (risk of emergence of resistance, clonal spread). Their main indications are examined in relation to their advantages and drawbacks. Overall, it is concluded that these important agents should be used in an educated fashion, based on a careful balance between their ease of use and efficacy vs. the risk of emerging resistance and toxicity. However, there is now substantial evidence to support use of the most potent drug at the appropriate dose whenever this is required.
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Affiliation(s)
- F Van Bambeke
- Unit of Cellular and Molecular Pharmacology, Catholic University of Louvain, Brussels.
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Abstract
The field of fluoroquinolone research is rapidly expanding. Bacterial targets are constantly changing to meet the demands of resistance. At present, new compounds are targeting respiratory pathogens, such as Streptococcus pneumoniae. However, problems such as phototoxicity, cardiotoxicity and CNS disturbances must be overcome. New promising fluoroquinolones include: HSR 903, LB 20304 and BAY 12-8039. Research in the field of mycobacteria, especially for Mycobacterium tuberculosis, is also underway.
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Affiliation(s)
- A Bryskier
- Hoechst Marion Roussel, Anti-infective Research Clinical Pharmacology, 102 Route de Noisy, 93230 Romainville Cedex, France
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26
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Noh HK, Lee JS, Kim Y, Hwang G, Chang JH, Shin H, Nam DH, Lee KH. Synthesis of the Intermediate of Gemifloxacin by the Chemoselective Hydrogenation of 4-Cyano-3-methoxyimino-1-(N-tert-butoxycarbonyl)pyrrolidine. Part 2. The Palladium Catalysts in Acidic Media. Org Process Res Dev 2004. [DOI: 10.1021/op0499122] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hyun Kuk Noh
- Department of Chemical Engineering and School of Environmental Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-dong, Pohang 790-784, Korea; Corporate R&D, LG Chemical Ltd., 104-1, Moonji-dong, Yusong-gu, Daejon, 305-380, Korea; and Chemical Development Division, LG Life Sciences, Ltd./R&D, 104-1, Moonji-dong, Yusong-gu, Daejon 305-380, Korea
| | - Jae Sung Lee
- Department of Chemical Engineering and School of Environmental Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-dong, Pohang 790-784, Korea; Corporate R&D, LG Chemical Ltd., 104-1, Moonji-dong, Yusong-gu, Daejon, 305-380, Korea; and Chemical Development Division, LG Life Sciences, Ltd./R&D, 104-1, Moonji-dong, Yusong-gu, Daejon 305-380, Korea
| | - Yeongdae Kim
- Department of Chemical Engineering and School of Environmental Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-dong, Pohang 790-784, Korea; Corporate R&D, LG Chemical Ltd., 104-1, Moonji-dong, Yusong-gu, Daejon, 305-380, Korea; and Chemical Development Division, LG Life Sciences, Ltd./R&D, 104-1, Moonji-dong, Yusong-gu, Daejon 305-380, Korea
| | - Gyohyun Hwang
- Department of Chemical Engineering and School of Environmental Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-dong, Pohang 790-784, Korea; Corporate R&D, LG Chemical Ltd., 104-1, Moonji-dong, Yusong-gu, Daejon, 305-380, Korea; and Chemical Development Division, LG Life Sciences, Ltd./R&D, 104-1, Moonji-dong, Yusong-gu, Daejon 305-380, Korea
| | - Jay Hyok Chang
- Department of Chemical Engineering and School of Environmental Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-dong, Pohang 790-784, Korea; Corporate R&D, LG Chemical Ltd., 104-1, Moonji-dong, Yusong-gu, Daejon, 305-380, Korea; and Chemical Development Division, LG Life Sciences, Ltd./R&D, 104-1, Moonji-dong, Yusong-gu, Daejon 305-380, Korea
| | - Hyunik Shin
- Department of Chemical Engineering and School of Environmental Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-dong, Pohang 790-784, Korea; Corporate R&D, LG Chemical Ltd., 104-1, Moonji-dong, Yusong-gu, Daejon, 305-380, Korea; and Chemical Development Division, LG Life Sciences, Ltd./R&D, 104-1, Moonji-dong, Yusong-gu, Daejon 305-380, Korea
| | - Do Hyun Nam
- Department of Chemical Engineering and School of Environmental Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-dong, Pohang 790-784, Korea; Corporate R&D, LG Chemical Ltd., 104-1, Moonji-dong, Yusong-gu, Daejon, 305-380, Korea; and Chemical Development Division, LG Life Sciences, Ltd./R&D, 104-1, Moonji-dong, Yusong-gu, Daejon 305-380, Korea
| | - Kyung Hee Lee
- Department of Chemical Engineering and School of Environmental Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-dong, Pohang 790-784, Korea; Corporate R&D, LG Chemical Ltd., 104-1, Moonji-dong, Yusong-gu, Daejon, 305-380, Korea; and Chemical Development Division, LG Life Sciences, Ltd./R&D, 104-1, Moonji-dong, Yusong-gu, Daejon 305-380, Korea
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27
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Noh HK, Lee JS, Kim Y, Chang JH, Shin H, Nam DH, Lee KH. Synthesis of the Intermediate of Gemifloxacin by the Chemoselective Hydrogenation of 4-Cyano-3-methoxyimino-1-(N-tert-butoxycarbonyl)pyrrolidine. Part 1. Screening of Metal Catalysts. Org Process Res Dev 2004. [DOI: 10.1021/op049913u] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hyun Kuk Noh
- Department of Chemical Engineering and School of Environmental Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-dong, Pohang 790-784, Korea; Corporate R&D, LG Chemical Ltd., 104-1, Moonji-dong, Yusong-gu, Daejon, 305-380, Korea; and Chemical Development Division, LG Life Sciences, Ltd./R&D, 104-1, Moonji-dong, Yusong-gu, Daejon 305-380, Korea
| | - Jae Sung Lee
- Department of Chemical Engineering and School of Environmental Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-dong, Pohang 790-784, Korea; Corporate R&D, LG Chemical Ltd., 104-1, Moonji-dong, Yusong-gu, Daejon, 305-380, Korea; and Chemical Development Division, LG Life Sciences, Ltd./R&D, 104-1, Moonji-dong, Yusong-gu, Daejon 305-380, Korea
| | - Yeongdae Kim
- Department of Chemical Engineering and School of Environmental Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-dong, Pohang 790-784, Korea; Corporate R&D, LG Chemical Ltd., 104-1, Moonji-dong, Yusong-gu, Daejon, 305-380, Korea; and Chemical Development Division, LG Life Sciences, Ltd./R&D, 104-1, Moonji-dong, Yusong-gu, Daejon 305-380, Korea
| | - Jay Hyok Chang
- Department of Chemical Engineering and School of Environmental Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-dong, Pohang 790-784, Korea; Corporate R&D, LG Chemical Ltd., 104-1, Moonji-dong, Yusong-gu, Daejon, 305-380, Korea; and Chemical Development Division, LG Life Sciences, Ltd./R&D, 104-1, Moonji-dong, Yusong-gu, Daejon 305-380, Korea
| | - Hyunik Shin
- Department of Chemical Engineering and School of Environmental Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-dong, Pohang 790-784, Korea; Corporate R&D, LG Chemical Ltd., 104-1, Moonji-dong, Yusong-gu, Daejon, 305-380, Korea; and Chemical Development Division, LG Life Sciences, Ltd./R&D, 104-1, Moonji-dong, Yusong-gu, Daejon 305-380, Korea
| | - Do Hyun Nam
- Department of Chemical Engineering and School of Environmental Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-dong, Pohang 790-784, Korea; Corporate R&D, LG Chemical Ltd., 104-1, Moonji-dong, Yusong-gu, Daejon, 305-380, Korea; and Chemical Development Division, LG Life Sciences, Ltd./R&D, 104-1, Moonji-dong, Yusong-gu, Daejon 305-380, Korea
| | - Kyung Hee Lee
- Department of Chemical Engineering and School of Environmental Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-dong, Pohang 790-784, Korea; Corporate R&D, LG Chemical Ltd., 104-1, Moonji-dong, Yusong-gu, Daejon, 305-380, Korea; and Chemical Development Division, LG Life Sciences, Ltd./R&D, 104-1, Moonji-dong, Yusong-gu, Daejon 305-380, Korea
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28
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Kim E, Koob YM, Chung DS. Chiral counter-current chromatography of gemifloxacin guided by capillary electrophoresis using (+)-(18-crown-6)-tetracarboxylic acid as a chiral selector. J Chromatogr A 2004; 1045:119-24. [PMID: 15378886 DOI: 10.1016/j.chroma.2004.06.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
(+)-(18-crown-6)-tetracarboxylic acid (18C6H4) has been known as a highly efficient chiral selector for resolving primary amine enantiomers in capillary electrophoresis (CE). We investigated the chiral separation of gemifloxacin using 18C6H4 in analytical counter-current chromatography (CCC). The separation conditions for CE, including the binding constant, pH, and run buffer constituents, provided a helpful guideline for chiral CCC. A successful separation of gemifloxacin enantiomers could be achieved using a two-phase solvent system composed of 1-butanol-ethyl-acetate-bis(2-hydroxyethyl)aminotris(hydroxymethyl)methane acetate buffer with a small amount of 18C6H4. The hydrophobicity of the solvent system and the 18C6H4 concentration were varied to optimize the chiral separation.
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Affiliation(s)
- Eunsook Kim
- School of Chemistry, Seoul National University, Seoul 151-747, South Korea
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29
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Dal Sasso M, Culici M, Bovio C, Braga PC. Gemifloxacin: effects of sub-inhibitory concentrations on various factors affecting bacterial virulence. Int J Antimicrob Agents 2003; 21:325-33. [PMID: 12672578 DOI: 10.1016/s0924-8579(02)00391-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
This study investigated the ability of sub-MICs of gemifloxacin to interfere with the bacterial virulence parameters of adhesiveness, haemagglutination, hydrophobicity and motility, as well as their interactions with host neutrophilic defences such as phagocytosis, killing and respiratory bursts. The adhesiveness of both Escherichia coli and Staphylococcus aureus was significantly reduced to a subinhibitory concentration of 1/32 MIC. Indirect fimbriation parameters, such as hydrophobicity and haemagglutination were significantly reduced at a concentration of 1/8 MIC, as was migration (swarming). Phagocytosis and the respiratory burst measured by means of chemiluminescence were not affected, but killing was significantly increased from 1/2 to 1/8 MIC. The interpolation of these pharmacodynamic findings with pharmacokinetic curves indicates that sub-MIC concentrations of gemifloxacin can prolong antimicrobial effects on virulence determinants up to 27 h after the antimicrobial concentration has fallen below the MIC value.
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Affiliation(s)
- M Dal Sasso
- Department of Pharmacology, Center of Respiratory Pharmacology, School of Medicine, University of Milan, Via Vanvitelli 32, 20129 Milan, Italy
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30
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Hyun MH, Han SC. Liquid chromatographic separation of the enantiomers of fluoroquinolone antibacterials on a chiral stationary phase based on a chiral crown ether. JOURNAL OF BIOCHEMICAL AND BIOPHYSICAL METHODS 2002; 54:235-43. [PMID: 12543501 DOI: 10.1016/s0165-022x(02)00117-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A chiral stationary phase (CSP) recently developed by bonding (diphenyl-substituted 1,1'-binaphthyl) crown ether to silica gel for the liquid chromatographic separation of enantiomers was applied to the resolution of investigational fluoroquinolone antibacterial agents including gemifloxacin (formerly LB20304a). All fluoroquinolone compounds used in this study were resolved quite well on the CSP. Especially, the resolution of gemifloxacin and its analogs on the CSP was excellent and even greater than that on the commercial Crownpak CR(+). The resolution was found to be dependent on the type and the content of organic, acidic, and inorganic modifiers added to the mobile phase and on the column temperature.
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Affiliation(s)
- Myung Ho Hyun
- Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Kuemjeong-Ku, Pusan 609-735, South Korea.
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31
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García-Calvo G, Parra A, Ponte C, Soriano F, Giménez MJ, Aguilar L. Urine bactericidal activity after administration of gemifloxacin and trovafloxacin single doses in a phase I study. Int J Antimicrob Agents 2002; 20:477-80. [PMID: 12458147 DOI: 10.1016/s0924-8579(02)00242-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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32
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Hyun MH, Han SC, Cho YJ, Jin JS, Lee W. Liquid chromatographic resolution of gemifloxacin mesylate on a chiral stationary phase derived from crown ether. Biomed Chromatogr 2002; 16:356-60. [PMID: 12210509 DOI: 10.1002/bmc.164] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A new racemic fluoroquinolone antibacterial agent, gemifloxacin mesylate, has been successfully resolved on a chiral stationary phase (CSP) derived from (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid. Compared to the Crownpak CR(+) column, the CSP used in this study was more effective for the resolution of racemic gemifloxacin mesylate, especially in terms of analytical time. The resolution of gemifloxacin mesylate enantiomers on the CSP was found to be dependent on the type and content of organic and acidic modifiers in the aqueous mobile phase and the column temperature.
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Affiliation(s)
- Myung Ho Hyun
- Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Pusan 609-735, Korea.
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33
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Braga PC, Dal SM, Woodnutt G. Staphylococcus aureus and Escherichia coli adhesion to human cells is reduced by sub-MICs of gemifloxacin. J Chemother 2002; 14:41-6. [PMID: 11892898 DOI: 10.1179/joc.2002.14.1.41] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
This study was designed to investigate the capacity of subinhibitory concentrations of the newly developed fluoroquinolone antibiotic gemifloxacin to interfere with the mechanism of bacterial adhesion. Human buccal epithelial cells were incubated with Staphylococcus aureus and Escherichia coli, and grown in the presence of serial dilutions of gemifloxacin from 1/2 MIC to 1/128 MIC. A significant decrease in the adhesion of both S. aureus and E. coli was observed from 1/2 MIC to 1/32 MIC. Morphological changes including filamentous forms of E. coli and cluster formation and swelling of S. aureus were also observed, mainly from 1/2 MIC to 1/8 and 1/16 MIC. These findings are discussed in terms of dose-effect relationships and the interpolation of this pharmacodynamic data with the pharmacokinetics curve of gemifloxacin.
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Affiliation(s)
- P C Braga
- Center of Respiratory Pharmacology, Department of Pharmacology, School of Medicine, University of Milan, Italy.
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34
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Yague G, Morris JE, Pan XS, Gould KA, Fisher LM. Cleavable-complex formation by wild-type and quinolone-resistant Streptococcus pneumoniae type II topoisomerases mediated by gemifloxacin and other fluoroquinolones. Antimicrob Agents Chemother 2002; 46:413-9. [PMID: 11796351 PMCID: PMC127068 DOI: 10.1128/aac.46.2.413-419.2002] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Gemifloxacin is a recently developed fluoroquinolone with potent activity against Streptococcus pneumoniae. We show that the drug is more active than moxifloxacin, gatifloxacin, levofloxacin, and ciprofloxacin against S. pneumoniae strain 7785 (MICs, 0.03 to 0.06 microg/ml versus 0.25, 0.25, 1, and 1 to 2 microg/ml, respectively) and against isogenic quinolone-resistant gyrA-parC mutants (MICs, 0.5 to 1 microg/ml versus 2 to 4, 2 to 4, 16 to 32, and 64 microg/ml, respectively). Gemifloxacin was also the most potent agent against purified S. pneumoniae DNA gyrase and topoisomerase IV in both catalytic inhibition and DNA cleavage assays. The drug concentrations that inhibited DNA supercoiling or DNA decatenation by 50% (IC(50)s) were 5 to 10 and 2.5 to 5.0 microM, respectively. Ciprofloxacin and levofloxacin were some four- to eightfold less active against either enzyme; moxifloxacin and gatifloxacin showed intermediate activities. In assays of drug-mediated DNA cleavage by gyrase and topoisomerase IV, the same order of potency was seen: gemifloxacin > moxifloxacin > gatifloxacin > levofloxacin approximately ciprofloxacin. For gemifloxacin, the drug concentrations that caused 25% linearization of the input DNA by gyrase and topoisomerase IV were 2.5 and 0.1 to 0.3 microM, respectively; these values were 4-fold and 8- to 25-fold lower than those for moxifloxacin, respectively. Each drug induced DNA cleavage by gyrase at the same spectrum of sites but with different patterns of intensity. Finally, for enzymes reconstituted with quinolone-resistant GyrA S81F or ParC S79F subunits, although cleavable-complex formation was reduced by at least 8- to 16-fold for all the quinolones tested, gemifloxacin was the most effective; e.g., it was 4- to 16-fold more active than the other drugs against toposiomerase IV with the ParC S79F mutation. It appears that the greater potency of gemifloxacin against both wild-type and quinolone-resistant S. pneumoniae strains arises from enhanced stabilization of gyrase and topoisomerase IV complexes on DNA.
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Affiliation(s)
- Genoveva Yague
- Molecular Genetics Group, Department of Biochemistry and Immunology, St. George's Hospital Medical School, University of London, London SW17 0RE, United Kingdom
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Kraiczy P, Weigand J, Wichelhaus TA, Heisig P, Backes H, Schäfer V, Acker G, Brade V, Hunfeld KP. In vitro activities of fluoroquinolones against the spirochete Borrelia burgdorferi. Antimicrob Agents Chemother 2001; 45:2486-94. [PMID: 11502519 PMCID: PMC90682 DOI: 10.1128/aac.45.9.2486-2494.2001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Little is known to date about the in vitro activity of fluoroquinolones against Borrelia species. Our study aimed at determining the in vitro activities of 15 quinolones against nine isolates of the Borrelia burgdorferi sensu lato complex in addition to one Borrelia valaisiana and one Borrelia bissettii tick isolate. For the determination of MICs, a standardized colorimetric microdilution method was applied. Determination of minimal borreliacidal concentrations providing 100% killing of the final inoculum (MBCs) after 72 h and time-kill experiments were performed by conventional culture in Barbour-Stoenner-Kelly medium in combination with dark-field microscopy. The rank order of potency on a microgram-per-milliliter basis for the substances with in vitro activity against B. burgdorferi was gemifloxacin (MIC at which 90% of the isolates tested are inhibited [MIC(90)], 0.12 microg/ml) > sitafloxacin (MIC(90), 0.5 microg/ml), grepafloxacin (MIC(90), 0.5 microg/ml) > gatifloxacin (MIC(90), 1 microg/ml), sparfloxacin (MIC(90), 1 microg/ml), trovafloxacin (MIC(90), 1 microg/ml) > moxifloxacin (MIC(90), 2 microg/ml), ciprofloxacin (MIC(90), 2 microg/ml) > levofloxacin (MIC(90), 4 microg/ml) > ofloxacin (MIC(90), 8 microg/ml), norfloxacin (MIC(90), 8 microg/ml) > fleroxacin (MIC(90), >16 microg/ml), and pefloxacin (MIC(90), 32 microg/ml) > nalidixic acid (MIC(90), 256 microg/ml). After 72 h of exposure, gemifloxacin was borreliacidal (100% killing) against the isolates investigated at a median MBC of 4 microg/ml. In the other compounds tested, median MBCs were higher (> or =8 microg/ml). Results of electron microscopy and time-kill studies clearly support an in vitro activity of some fluoroquinolones against borreliae. Our study demonstrates for the first time the enhanced in vitro effectiveness of some of the recently introduced 4-quinolones against B. burgdorferi.
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Affiliation(s)
- P Kraiczy
- Institute of Medical Microbiology, University Hospital of Frankfurt, D-60596 Frankfurt/Main, Germany
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36
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Lopez H, Stepanik D, Vilches V, Scarano S, Sarachian B, Mikaelian G, Finlay J, Sucari A. Comparative in vitro activity of gemifloxacin against gram-positive and gram-negative clinical isolates in Argentina. Diagn Microbiol Infect Dis 2001; 40:187-92. [PMID: 11576792 DOI: 10.1016/s0732-8893(01)00271-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The in vitro activity of gemifloxacin against 1,000 clinical isolates of 147 Streptococcus pneumoniae (115, penicilin susceptible; 26, intermediate penicillin-resistant and 6, penicillin-resistant), 127 Hemophilus influenzae (109, beta lactamasa non-producer; 18, beta lactamase producers), 95 Streptococcus pyogenes (6, azytromycin-resistant), 84 Moraxella catarrhalis (79, beta lactamase producers), 110 Staphilococcus aureus (89, methicillin-susceptible; 21, methicilin-resistant), 98 Eenterococcus faecalis and 339 Enterobacteriacea, (recovered from patients with respiratory tract infection; skin and soft tissue infection and urinary tract infection), was compared with the activities of four fluorquinolones and five other antimicrobial agents. Of the quinolones tested, gemifloxacin was the most potent against Streptococcus pneumoniae, including penicillin intermediate and resistant strains. Mic(90) values obtained for gemifloxacin, ciprofloxacin, ofloxacin, levofloxacin and trvafloxacin were 0.03, 2, 2, 1 and 0.25 mg/L respectively. Gemifloxacin was 16 fold more potent than ciprofloxacin against methicillin-susceptible Staphylococcus aureus and 32 fold more potent than ciprofloxacin against Streptococcus pyogenes. When tested against Hemophilus influenzae, Moraxella catarrhalis and Enterobacteriaceae, all the quinolones showed similar activity. Our results demonstrate that gemifloxacin has similar activity than the other quinolones tested against Gram-negative organisms and is considerably more potent against Gram-positive organisms.
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Affiliation(s)
- H Lopez
- Centro de Infectología, Buenos Aires, Argentina.
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37
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Hoban DJ, Bouchillon SK, Johnson JL, Zhanel GG, Butler DL, Miller LA, Poupard JA. Comparative in vitro activity of gemifloxacin, ciprofloxacin, levofloxacin and ofloxacin in a North American surveillance study. Diagn Microbiol Infect Dis 2001; 40:51-7. [PMID: 11448564 DOI: 10.1016/s0732-8893(01)00241-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The in vitro activity of gemifloxacin, a new fluoroquinolone, was compared to three marketed fluoroquinolones; ciprofloxacin, levofloxacin and ofloxacin against over 4,000 recent clinical isolates covering 29 species isolated in the United States and Canada between 1997-1999. Based on MIC(90)s, gemifloxacin was the most potent fluoroquinolone tested against a majority of Gram-positive isolates: Streptococcus pneumoniae, penicillin resistant S. pneumoniae, macrolide resistant S. pneumoniae, ciprofloxacin non-susceptible (MIC > or = 4 microg/mL) S. pneumoniae, S. pyogenes, S. agalactiae, viridans streptococci, Enterococcus faecalis, methicillin susceptible Staphylococcus aureus, methicillin resistant S. aureus, S. epidermidis, S. hemolyticus, and S. saprophyticus. Against Enterobacteriaceae and aerobic non-Enterobacteriaceae Gram-negatives, gemifloxacin was usually comparable to ciprofloxacin and levofloxacin and more potent than ofloxacin for the following species: Citrobacter freundii, Enterobacter aerogenes, E. cloacae, Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae, Morganella morganii, Proteus mirabilis, P. vulgaris, Providencia stuartii, Serratia marcescens, Acinetobacter lwoffii, A. baumannii, Burkholderia cepacia, Haemophilus influenzae, H. parainfluenzae, Moraxella catarrhalis, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia. Gemifloxacin was generally 16-64 fold more potent than the other fluoroquinolones tested against Gram-positive organisms and retains excellent activity comparable with ciprofloxacin and levofloxacin against a majority of Gram-negative pathogens.
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Affiliation(s)
- D J Hoban
- Laboratories International for Microbiology Studies, Rolling Meadows, IL, USA.
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38
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Affiliation(s)
- M Takemura
- New Product Research Laboratories I, Daiichi Pharmaceutical Company, Ltd., Tokyo, Japan.
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39
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Allen A, Bygate E, Vousden M, Oliver S, Johnson M, Ward C, Cheon A, Choo YS, Kim I. Multiple-dose pharmacokinetics and tolerability of gemifloxacin administered orally to healthy volunteers. Antimicrob Agents Chemother 2001; 45:540-5. [PMID: 11158752 PMCID: PMC90324 DOI: 10.1128/aac.45.2.540-545.2001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Gemifloxacin mesylate (SB-265805-S, LB-20304a) is a potent, novel fluoroquinolone agent with a broad spectrum of antibacterial activity. The pharmacokinetics and tolerability of oral gemifloxacin were characterized in two parallel group studies in healthy male volunteers after doses of 160, 320, 480, and 640 mg once daily for 7 days. Multiple serum or plasma and urine samples were collected on days 1 and 7 and were analyzed for gemifloxacin by high-performance liquid chromatography (HPLC)-fluorescence (study 1) or HPLC-mass spectrometry (study 2). Safety assessments included vital signs, 12-lead electrocardiogram (ECG) readings, hematology, clinical chemistry, urinalysis, and adverse experience monitoring. Gemifloxacin was rapidly absorbed, with a time to maximum concentration of approximately 1 h after dosing followed by a biexponential decline in concentration. Generally, maximum concentration and area under the concentration-time curve (AUC) increased linearly with dose after either single or repeat doses. Mean +/- standard deviation values of AUC(0-tau) on day 7 were 4.92 +/- 1.08, 9.06 +/- 2.20, 12.2 +/- 3.69, and 20.1 +/- 3.67 microg x h/ml following 160-, 320-, 480-, and 640-mg doses, respectively. The terminal-phase half-life was approximately 7 to 8 h, independent of dose, and was similar following single and repeated administrations. There was minimal accumulation of gemifloxacin after multiple dosing. Approximately 20 to 30% of the administered dose was excreted unchanged in the urine. The renal clearance was 160 ml/min on average after single and multiple doses, which was slightly greater than the accepted glomerular filtration rate (approximately 120 ml/min). These data show that the pharmacokinetics of gemifloxacin are linear and independent of dose. Gemifloxacin was generally well tolerated, although one subject was withdrawn from the study after 6 days at 640 mg for mild, transient elevations of alanine aminotransferase and aspartate aminotransferase not associated with any clinical signs or symptoms. There were no other significant changes in clinical chemistry, hematology or urinalysis parameters, vital signs, or ECG readings. In conclusion, the results of these studies, combined with the antibacterial spectrum and potency, support the further investigation of once-daily administration of gemifloxacin for indications such as respiratory tract and urinary tract infections.
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Affiliation(s)
- A Allen
- Drug Metabolism and Pharmacokinetics, SmithKline Beecham Pharmaceuticals, Welwyn, Herts, United Kingdom.
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40
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Allen A, Bird N, Dixon R, Hickmott F, Pay V, Smith A, Stahl M. Effect of Cimetidine on the Pharmacokinetics of Oral Gemifloxacin in Healthy Volunteers. Clin Drug Investig 2001. [DOI: 10.2165/00044011-200121070-00008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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41
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Fuchs PC, Barry AL, Brown SD. In vitro activity of gemifloxacin against contemporary clinical bacterial isolates from eleven North American medical centers, and assessment of disk diffusion test interpretive criteria. Diagn Microbiol Infect Dis 2000; 38:243-53. [PMID: 11146251 DOI: 10.1016/s0732-8893(00)00198-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A total of 5499 contemporary clinical bacterial isolates were tested for susceptibility to gemifloxacin and four comparison agents by the broth microdilution method. Gemifloxacin activity against Enterobacteriaceae was generally comparable to that of ciprofloxacin and trovafloxacin, but because the gemifloxacin susceptible MIC breakpoint is lower, the percent susceptible to gemifloxacin was less than that to the other quinolones for some species. All agents were less active against Pseudomonas spp. Gemifloxacin was the most active agent tested against Gram-positive species, though Corynebacterium jeikeium and vancomycin-resistant enterococci were uniformly resistant to all agents tested. With staphylococci, a bimodal distribution of gemifloxacin MICs corresponded with susceptibility or resistance to ciprofloxacin. The significance of ciprofloxacin-resistant staphylococci that have susceptible gemifloxacin MICs is not known at this time. Disk diffusion tests were performed simultaneously with gemifloxacin and trovafloxacin as a control drug. Gemifloxacin MIC-zone diameter scattergrams indicated that interpretive discrepancy rates based on previously proposed criteria when using < or = 0.5 microg/ml as the susceptible MIC breakpoint was within acceptable limits. However, with the currently proposed MIC breakpoint of < or = 0.25 microg/ml, tentative zone diameter breakpoints of > or = 22 mm for susceptible, 19-21 mm for intermediate and < or = 18 mm for resistant are proposed.
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Affiliation(s)
- P C Fuchs
- The Clinical Microbiology Institute, 9725 SW Commerce Circle, Wilsonville, OR 97070, USA.
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42
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García I, Pascual A, Ballesta S, Joyanes P, Perea EJ. Intracellular penetration and activity of gemifloxacin in human polymorphonuclear leukocytes. Antimicrob Agents Chemother 2000; 44:3193-5. [PMID: 11036051 PMCID: PMC101631 DOI: 10.1128/aac.44.11.3193-3195.2000] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The intracellular penetration and activity of gemifloxacin in human polymorphonuclear leukocytes (PMN) were evaluated. Gemifloxacin reached intracellular concentrations eight times higher than extracellular concentrations. The uptake was rapid, reversible, and nonsaturable and was affected by environmental temperature, cell viability, and membrane stimuli. At therapeutic extracellular concentrations, gemifloxacin showed intracellular activity against Staphylococcus aureus.
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Affiliation(s)
- I García
- Department of Microbiology, School of Medicine, University of Seville, Seville 41009, Spain
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43
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Heaton VJ, Ambler JE, Fisher LM. Potent antipneumococcal activity of gemifloxacin is associated with dual targeting of gyrase and topoisomerase IV, an in vivo target preference for gyrase, and enhanced stabilization of cleavable complexes in vitro. Antimicrob Agents Chemother 2000; 44:3112-7. [PMID: 11036032 PMCID: PMC101612 DOI: 10.1128/aac.44.11.3112-3117.2000] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We investigated the roles of DNA gyrase and topoisomerase IV in determining the susceptibility of Streptococcus pneumoniae to gemifloxacin, a novel fluoroquinolone which is under development as an antipneumococcal drug. Gemifloxacin displayed potent activity against S. pneumoniae 7785 (MIC, 0.06 microgram/ml) compared with ciprofloxacin (MIC, 1 to 2 microgram/ml). Complementary genetic and biochemical approaches revealed the following. (i) The gemifloxacin MICs for isogenic 7785 mutants bearing either parC or gyrA quinolone resistance mutations were marginally higher than wild type at 0.12 to 0.25 microgram/ml, whereas the presence of both mutations increased the MIC to 0.5 to 1 microgram/ml. These data suggest that both gyrase and topoisomerase IV contribute significantly as gemifloxacin targets in vivo. (ii) Gemifloxacin selected first-step gyrA mutants of S. pneumoniae 7785 (gemifloxacin MICs, 0.25 microgram/ml) encoding Ser-81 to Phe or Tyr, or Glu-85 to Lys mutations. These mutants were cross resistant to sparfloxacin (which targets gyrase) but not to ciprofloxacin (which targets topoisomerase IV). Second-step mutants (gemifloxacin MICs, 1 microgram/ml) exhibited an alteration in parC resulting in changes of ParC hot spot Ser-79 to Phe or Tyr. Thus, gyrase appears to be the preferential in vivo target. (iii) Gemifloxacin was at least 10- to 20-fold more effective than ciprofloxacin in stabilizing a cleavable complex (the cytotoxic lesion) with either S. pneumoniae gyrase or topoisomerase IV enzyme in vitro. These data suggest that gemifloxacin is an enhanced affinity fluoroquinolone that acts against gyrase and topoisomerase IV in S. pneumoniae, with gyrase the preferred in vivo target. The marked potency of gemifloxacin against wild type and quinolone-resistant mutants may accrue from greater stabilization of cleavable complexes with the target enzymes.
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Affiliation(s)
- V J Heaton
- Molecular Genetics Group, Department of Biochemistry, St. George's Hospital Medical School, University of London, London SW17 0RE, United Kingdom
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44
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Hoban DJ, Bouchillon SK, Karlowsky JA, Johnson JL, Butler DL, Miller LA, Poupard JA. A comparative In vitro surveillance study of gemifloxacin activities against 2,632 recent Streptococcus pneumoniae isolates from across Europe, North America, and South America. The Gemifloxacin Surveillance Study Research Group. Antimicrob Agents Chemother 2000; 44:3008-11. [PMID: 11036014 PMCID: PMC101594 DOI: 10.1128/aac.44.11.3008-3011.2000] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
From 1997 to 1999, 94 study centers in 15 European, 3 North American, and 2 South American countries contributed 2,632 isolates of Streptococcus pneumoniae to an international antimicrobial susceptibility testing study. Only 62.0% of isolates were susceptible to penicillin, while 22.3% were penicillin intermediate and 15.6% were penicillin resistant. Resistance to trimethoprim-sulfamethoxazole (24.4%), azithromycin (26.0%), and clarithromycin (27.1%) was also highly prevalent. For the penicillin-resistant isolates (n = 411), the MICs at which 90% of isolates are inhibited (MIC(90)s) for gemifloxacin, levofloxacin, ofloxacin, clarithromycin, and azithromycin were 0.03, 1, 2, >16, and >64 microgram/ml, respectively. Similarly, for isolates resistant to both azithromycin and clarithromycin (n = 649), gemifloxacin, levofloxacin, ofloxacin, and penicillin MIC(90)s were 0.03, 1, 2, and 4 microgram/ml, respectively. Overall rates of resistance to trovafloxacin (0.3%), levofloxacin (0.3%), grepafloxacin (0.6%), and ofloxacin (0.7%) were low. For ofloxacin-intermediate and -resistant isolates (n = 142), gemifloxacin had the lowest MIC(90) (0.12 microgram/ml) compared to the MIC(90)s of trovafloxacin (0.5 microgram/ml), grepafloxacin (1 microgram/ml), and levofloxacin (2 microgram/ml). For all S. pneumoniae isolates tested, gemifloxacin MICs were </=0.5 microgram/ml, suggesting that gemifloxacin has the potential to be used as a treatment for pneumococcal infections, including those arising from isolates resistant to beta-lactams and macrolides.
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Affiliation(s)
- D J Hoban
- Laboratories International for Microbiology Studies, Rolling Meadows, Illinois, USA.
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45
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Separation of the stereoisomers of racemic fluoroquinolone antibacterial agents on a crown-ether-based chiral HPLC stationary phase. Chromatographia 2000. [DOI: 10.1007/bf02535722] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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46
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Tanaka M, Tunoe H, Mochida O, Kanayama A, Saika T, Kobayashi I, Naito S. Antimicrobial activity of gemifloxacin (SB-265805), a newer fluoroquinolone, against clinical isolates of Neisseria gonorrhoeae, including fluoroquinolone-resistant isolates. Diagn Microbiol Infect Dis 2000; 38:109-13. [PMID: 11035242 DOI: 10.1016/s0732-8893(00)00180-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Antimicrobial activity of gemifloxacin (SB-265805), a newly developed fluoroquinolone, to Japanese isolates of Neisseria gonorrhoeae was compared with those of various fluoroquinolones, including norfloxacin, ciprofloxacin, tosufloxacin, levofloxacin, sparfloxacin, and trovafloxacin. Among the fluoroquinolones tested, gemifloxacin was most active against N. gonorrhoeae isolates. The MIC90 values of gemifloxacin for 94 N. gonorrhoeae isolated from 1992 through 1993 and 100 isolated from 1996 through 1997 were 0.03 and 0.125 microg/ml, respectively. On the other hand, MIC90 values of the other fluoroquinolone for the 1992-1993 isolates and the 1996-1997 isolates ranged from 0.125 to 2 microg/ml and from 0.5 to 8 microg/ml, respectively. Gemifloxacin was also the most potent fluoroquinolone against 31 ciprofloxacin-resistant isolates with the ciprofloxacin MIC of 1 to 16 microg/ml, for which the gemifloxacin MIC50 and MIC90 values were 0.25 and 2 microg/ml, respectively. Moreover, the activity of gemifloxacin against fluoroquinolone-resistant gonococcal isolates containing multiple amino acid substitutions in both GyrA and ParC proteins was superior to those of the other compounds.
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Affiliation(s)
- M Tanaka
- Department of Urology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
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47
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Doyle E, Fowles SE, McDonnell DF, McCarthy R, White SA. Rapid determination of gemifloxacin in human plasma by high-performance liquid chromatography-tandem mass spectrometry. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2000; 746:191-8. [PMID: 11076071 DOI: 10.1016/s0378-4347(00)00333-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A method was developed for the determination of gemifloxacin (I) in human plasma using high-performance liquid chromatography-tandem mass spectrometry. Prior to analysis, the protein in plasma samples was precipitated with acetonitrile containing [13C2H3] gemifloxacin (II) to act as an internal standard. The supernatant was injected onto a PLRP-S column without any further clean-up. The mass spectrometer was operated in positive ion mode, employing a heat assisted nebulisation. electrospray interface. Ions were detected in multiple reaction monitoring (MRM) mode. The assay requires 50 microl of plasma and is precise and accurate within the range 10-5,000 ng/ml. The average within-run and between-run coefficients of variation were <11% at 10 ng/ml and greater concentrations. The average accuracy of validation standards was generally within +/-7% of the nominal concentration. There was no evidence of instability of I in human plasma following three complete freeze-thaw cycles and samples can safely be stored for at least 6 months at -20 degrees C. The method proved very robust and was successfully applied to the analysis of clinical samples from patients dosed with gemifloxacin.
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Affiliation(s)
- E Doyle
- Department of Drug Analysis, SmithKline Beecham Pharmaceuticals, Welwyn, Hertfordshire, UK
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48
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Allen A, Bygate E, Clark D, Lewis A, Pay V. The effect of food on the bioavailability of oral gemifloxacin in healthy volunteers. Int J Antimicrob Agents 2000; 16:45-50. [PMID: 11185412 DOI: 10.1016/s0924-8579(00)00181-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The effect of food on the bioavailability of gemifloxacin was investigated at two doses (320 and 640 mg) in healthy male and female volunteers. A total of 21 subjects entered the open label, four-period crossover study. Each subject received single oral doses of 320 and 640 mg in the fasted state and after a high fat meal, on separate dosing occasions in a randomised fashion. There was on average, a 3% (95% CI (0.88, 1.07)) and 12% (95% CI (0.79, 0.97)) reduction in AUC and a 12% (95% CI (0.76, 1.02) and 14% (0.75, 1.00) reduction in Cmax after the 320- and 640-mg doses, respectively. The results indicate a minor effect of food on bioavailability of gemifloxacin (320 and 640 mg). Such a reduction in systemic exposure would be considered to be not clinically relevant. Tmax data were inconclusive but indicated a possible slight delay in Tmax of, on average, 0.75 and 0.21 h after the 320- and 640-mg doses, respectively. Delays of this magnitude in reaching maximum concentrations are unlikely to be of clinical importance for an antibiotic drug. Both 320 and 640 mg gemifloxacin were well tolerated in fed and fasted states by healthy volunteers. It can be concluded therefore, that gemifloxacin can be taken with and without food.
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Affiliation(s)
- A Allen
- Drug Metabolism and Pharmacokinetics, SmithKline Beecham Pharmaceuticals, The Frythe, Welwyn, Herts, UK.
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49
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Jones RN, Erwin ME. Development of gemifloxacin in vitro susceptibility test methods for gonococci including quality control guidelines. The Quality Control Study Group. Diagn Microbiol Infect Dis 2000; 37:195-201. [PMID: 10904193 DOI: 10.1016/s0732-8893(00)00139-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Gemifloxacin (formerly SB-265805 or LB20304a) is a new fluoronapthyridone with documented activity against Gram-positive and -negative organisms. The activity of gemifloxacin was tested against 150 Neisseria gonorrhoeae strains, using reference agar dilution, standardized disk diffusion, and Etest (AB BIODISK, Solna, Sweden) methods. Gemifloxacin was very potent against ciprofloxacin (CIPRO)-susceptible strains (MIC(90,) 0.008 microg/ml) but was significantly less active against the CIPRO-resistant gonococci (MIC(90,) 0.12 microg/ml). Etest and reference agar dilution MIC results showed excellent correlation (r = 0.96), and 98.7% MICs were within +/- one log(2) dilution. Agar dilution MICs were also compared to zone diameters obtained using gemifloxacin 5-microg disks; and complete intermethod categorical agreement (100%) was achieved applying breakpoints proposed as follows: < or =0.25 microg/ml (zone, > or =25 mm) for susceptible and > or =1 microg/ml (zone, < or =21 mm) for resistant. Gemifloxacin MIC and disk diffusion te quality control (QC) ranges were established for N. gonorrhoeae ATCC 49226. Data were collected from > or = seven laboratories, three GC agar medium lots for both agar MICs and disk methods, and two lots each of the 5- and 10-microg disks. The proposed MIC QC range was 0.002 to 0.016 microg/ml and the calculated mm zone ranges (median +/- 0.5x average mm range) for both disks were similar, but contained only 88.1 to 91.9% of participant results. To achieve the acceptable > or = 95% of all study results within range, a 43 to 54 mm limits (5-microg disks) were necessary. The excellent broad-spectrum activity and a low reported adverse effects profile of gemifloxacin shows a potential for treatment of fluoroquinolone-resistant gonorrhea.
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Affiliation(s)
- R N Jones
- University of Iowa College of Medicine, Medical Microbiology Division, Department of Pathology, C606 GH, 200 Hawkins Drive, Iowa City, IA 52242, USA.
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50
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Abstract
The quinolones have evolved from antibacterial agents with a limited spectrum of predominantly anti-gram-negative antimicrobial activity and a restricted number of indications to a class of widely used oral (and, in some cases, intravenous) antibiotics with extensive indications for infections caused by many bacterial pathogens in most body tissues and fluids. This evolutionary pattern has arisen through the development of new core and side-chain structures, with associated improvements in activity, pharmacokinetics and tolerability, and through the selection of molecules that remain useful and well tolerated. This review describes the progress of the quinolones from the first to the third (IIIa and IIIb) generations. Special attention is given to gemifloxacin, currently the most developmentally advanced third-generation quinolone, which has enhanced in vitro gram-positive antimicrobial activity and no troublesome adverse drug reactions. Preliminary data indicate that gemifloxacin should prove to be an important addition to the fluoroquinolone class. Further clinical trial data are awaited with interest.
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Affiliation(s)
- P Ball
- University of St Andrews, Fife, Scotland, UK.
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