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RT-qPCR Detection of SARS-CoV-2: No Need for a Dedicated Reverse Transcription Step. Int J Mol Sci 2022; 23:ijms23031303. [PMID: 35163227 PMCID: PMC8835954 DOI: 10.3390/ijms23031303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 12/27/2021] [Accepted: 01/21/2022] [Indexed: 11/16/2022] Open
Abstract
Reverse transcription of RNA coupled to amplification of the resulting cDNA by the polymerase chain reaction (RT-PCR) is one of the principal molecular technologies in use today, with applications across all areas of science and medicine. In its real-time, fluorescence-based usage (RT-qPCR), it has long been a core technology driving the accurate, rapid and sensitive laboratory diagnosis of infectious diseases. However, RT-qPCR protocols have changed little over the past 30 years, with the RT step constituting a significant percentage of the time taken to complete a typical RT-qPCR assay. When applied to research investigations, reverse transcription has been evaluated by criteria such as maximum yield, length of transcription, fidelity, and faithful representation of an RNA pool. Crucially, however, these are of less relevance in a diagnostic RT-PCR test, where speed and sensitivity are the prime RT imperatives, with specificity contributed by the PCR component. We propose a paradigm shift that omits the requirement for a separate high-temperature RT step at the beginning of an RT-qPCR assay. This is achieved by means of an innovative protocol that incorporates suitable reagents with a revised primer and amplicon design and we demonstrate a proof of principle that incorporates the RT step as part of the PCR assay setup at room temperature. Use of this modification as part of a diagnostic assay will of course require additional characterisation, validation and optimisation of the PCR step. Combining this revision with our previous development of fast qPCR protocols allows completion of a 40 cycle RT-qPCR run on a suitable commercial instrument in approximately 15 min. Even faster times, in combination with extreme PCR procedures, can be achieved.
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2
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Synthesis, molecular modeling, and pharmacological evaluation of new 2-substituted benzoxazole derivatives as potent anti-inflammatory agents. Struct Chem 2019. [DOI: 10.1007/s11224-019-01374-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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3
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Zhu YM, Shen JK, Wang JM, Jiang X, Tang T. Nickel-Catalyzed Ligand-Free Systhesis of Benzoxazoles and Oxazolines via Isocyanide Insertion. HETEROCYCLES 2014. [DOI: 10.3987/com-14-12996] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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4
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Graf N, Altenbuchner J. Functional characterization and application of a tightly regulated MekR/P mekA expression system in Escherichia coli and Pseudomonas putida. Appl Microbiol Biotechnol 2013; 97:8239-51. [PMID: 23771781 DOI: 10.1007/s00253-013-5030-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 05/28/2013] [Accepted: 05/30/2013] [Indexed: 01/30/2023]
Abstract
A methyl ethyl ketone (MEK)-inducible system based on the broad-host-range plasmid pBBR1MCS2 and on the P mekA promoter region of the MEK degradation operon of Pseudomonas veronii MEK700 was characterized in Escherichia coli JM109 and Pseudomonas putida KT2440. For validation, β-galactosidase (lacZ) was used as a reporter. The novel system, which is positively regulated by MekR, a member of the AraC/XylS family of regulators, was shown to be subject to carbon catabolite repression by glucose, which, however, could not be attributed to the single action of the global regulators Crc and PtsN. An advantage is its extremely tight regulation accompanied with three magnitudes of fold increase of gene expression after treatment with MEK. The transcriptional start site of P mekA was identified by primer extension, thereby revealing a potential stem-loop structure at the 5' end of the mRNA. Since MekR was highly insoluble, its putative binding site was identified through sequence analysis. The operator seems to be composed of a 15-bp tandem repeat (CACCN5CTTCAA) separated by a 6-bp spacer region, which resembles known binding patterns of other members of the AraC/XylS family. Subsequent mutational modifications of the putative operator region confirmed its importance for transcriptional activation. As the -35 promoter element seems to be overlapped by the putative operator, a class II activation mechanism is assumed.
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Affiliation(s)
- Nadja Graf
- Institut für Industrielle Genetik, Universität Stuttgart, Allmandring 31, 70569, Stuttgart, Germany
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5
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Turan-Zitouni G, Kaplancikli ZA, Uçucu Ü, Özdemir A, Chevallet P, Tunali Y. SYNTHESIS OF SOME 2-[(BENZAZOLE-2-YL)THIO]-DIPHENYLMETHYLACETAMIDE DERIVATIVES AND THEIR ANTIMICROBIAL ACTIVITY. PHOSPHORUS SULFUR 2010. [DOI: 10.1080/10426500490474851] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- G. Turan-Zitouni
- a Anadolu University, Faculty of Pharmacy, Department of Pharmaceutical Chemistry , Eskisehir, Turkey
| | | | - Ü. Uçucu
- a Anadolu University, Faculty of Pharmacy, Department of Pharmaceutical Chemistry , Eskisehir, Turkey
| | - A. Özdemir
- a Anadolu University, Faculty of Pharmacy, Department of Pharmaceutical Chemistry , Eskisehir, Turkey
| | - P. Chevallet
- b Montpellier University, Faculty of Pharmacy, Department of Pharmaceutical Chemistry , Montpellier, France
| | - Y. Tunali
- c Anadolu University, Faculty of Pharmacy, Department of Microbiology , Eskisehir, Turkey
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6
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Single-molecule study of DNA polymerization activity of HIV-1 reverse transcriptase on DNA templates. J Mol Biol 2009; 395:995-1006. [PMID: 19968999 DOI: 10.1016/j.jmb.2009.11.072] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Revised: 11/12/2009] [Accepted: 11/30/2009] [Indexed: 11/20/2022]
Abstract
HIV-1 RT (human immunodeficiency virus-1 reverse transcriptase) is a multifunctional polymerase responsible for reverse transcription of the HIV genome, including DNA replication on both RNA and DNA templates. During reverse transcription in vivo, HIV-1 RT replicates through various secondary structures on RNA and single-stranded DNA (ssDNA) templates without the need for a nucleic acid unwinding protein, such as a helicase. In order to understand the mechanism of polymerization through secondary structures, we investigated the DNA polymerization activity of HIV-1 RT on long ssDNA templates using a multiplexed single-molecule DNA flow-stretching assay. We observed that HIV-1 RT performs fast primer extension DNA synthesis on single-stranded regions of DNA (18.7 nt/s) and switches its activity to slow strand displacement synthesis at DNA hairpin locations (2.3 nt/s). Furthermore, we found that the rate of strand displacement synthesis is dependent on the GC content in hairpin stems and template stretching force. This indicates that the strand displacement synthesis occurs through a mechanism that is neither completely active nor passive: that is, the opening of the DNA hairpin is driven by a combination of free energy released during dNTP (deoxyribonucleotide triphosphate) hydrolysis and thermal fraying of base pairs. Our experimental observations provide new insight into the interchanging modes of DNA replication by HIV-1 RT on long ssDNA templates.
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7
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Synthesis of some novel 2-substituted benzoxazoles as anticancer, antifungal, and antimicrobial agents. Med Chem Res 2008. [DOI: 10.1007/s00044-007-9076-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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8
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Arisoy M, Temiz-Arpaci O, Yildiz I, Kaynak-Onurdag F, Aki E, Yalcin I, Abbasoglu U. Synthesis, antimicrobial activity and QSAR studies of 2,5-disubstituted benzoxazoles. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2008; 19:589-612. [PMID: 18853304 DOI: 10.1080/10629360802348738] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
In this study, a new series of 2,5-disubstituted benzoxazoles was synthesized and their structures were elucidated by elemental analysis, MASS, (1)H-NMR, (13)C-NMR and IR spectral data. Newly and previously synthesized 2,5-disubstituted benzoxazole derivatives were evaluated for antibacterial and antifungal activity against standard strains and their drug-resistant isolates. Microbiological results showed that the compounds presented a large spectrum of activity having MIC values of 250-7.8 microg mL(-1) against the tested microorganisms. Among the newly synthesized derivatives 3-22, compound 11 was the most active against Candida krusei out of all; however, it was one dilution less potent than standard drug fluconazole. In addition, all the new and previous compounds were more active than standard drugs ampicillin trihydrate and rifampicin against Pseudomonas aeruginosa and its gentamicin-resistant isolate. The 2D-QSAR (Quantitative Structure-Activity Relationship) analysis of a set of newly and previously synthesized benzoxazoles tested for growth inhibitory activity against methicillin-resistant Staphylococcus aureus (MRSA) was also performed by using multivariable regression analysis. The activity contributions for substituent effects of these compounds were determined from the correlation equation for predictions of the lead optimization.
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Affiliation(s)
- M Arisoy
- Faculty of Pharmacy, Department of Pharmaceutical Chemistry, Ankara University, Ankara, Turkey
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9
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Munshi V, Lu M, Felock P, Barnard RJO, Hazuda DJ, Miller MD, Lai MT. Monitoring the development of non-nucleoside reverse transcriptase inhibitor-associated resistant HIV-1 using an electrochemiluminescence-based reverse transcriptase polymerase assay. Anal Biochem 2007; 374:121-32. [PMID: 17964275 DOI: 10.1016/j.ab.2007.10.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2007] [Revised: 10/01/2007] [Accepted: 10/02/2007] [Indexed: 10/22/2022]
Abstract
Reverse transcriptase (RT) plays an essential role in the HIV-1 replication process, which converts a single-strand RNA into a double-strand DNA via polymerase and RNase H activities. Therefore, inhibition of RT has been one of the primary therapeutic strategies for suppressing the replication of HIV-1. To facilitate the process of discovering the next generation of antiretroviral agents, this study presents a highly sensitive and nonradioactive RT polymerase assay that is based on electrochemiluminescence (ECL) technology, where a ruthenylated dUTP (Ru-dUTP) is employed as one of the dNTPs. The concentration of the RT enzymes required for the assay can be as low as 1 pM, enabling us to evaluate inhibitors with low picomolar potency. More importantly, the assay is capable of detecting endogenous RT activity in cell-free viruses. Therefore, the assay was applied to monitor the development of resistance mutation(s) by viruses under the treatment with a non-nucleoside reverse transcriptase inhibitor (NNRTI) in cell culture. The magnitude of resistance of the resulting mutant viruses was assessed directly by the assay, eliminating the need for cloning, expressing, and purifying the RT mutants.
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Affiliation(s)
- Vandna Munshi
- Department of Antiviral Research, Merck Research Laboratories, West Point, PA 19486, USA
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10
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Oksuzoglu E, Temiz-Arpaci O, Tekiner-Gulbas B, Eroglu H, Sen G, Alper S, Yildiz I, Diril N, Aki-Sener E, Yalcin I. A study on the genotoxic activities of some new benzoxazoles. Med Chem Res 2007. [DOI: 10.1007/s00044-007-9005-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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11
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Temiz-Arpaci O, Ozdemir A, Yalçin I, Yildiz I, Aki-Sener E, Altanlar N. Synthesis and Antimicrobial Activity of Some 5-[2-(Morpholin-4-yl)acetamido] and/or 5-[2-(4-Substituted piperazin-1-yl)acetamido]-2-(p-substituted phenyl)benzoxazoles. Arch Pharm (Weinheim) 2005; 338:105-11. [PMID: 15765492 DOI: 10.1002/ardp.200400923] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In this study, a series of twelve novel 5-[2-(morpholin-4-yl)acetamido] and/or 5-[2-(4-substituted pip-erazine-1-yl)acetamido]-2-(p-substituted phenyl]benzoxazole derivatives have been synthesized and their structures were confirmed by IR, (1)H NMR, and mass spectral data. These compounds were prepared by reacting 5-(2-chloroacetamido)-2-(4-p-substituted-phenyl)benzoxazoles, which were obtained by using 5-amino-2-[p-substituted-phenyl]benzoxazoles with chloroacetyl chloride, in the presence of morpholine or 1-substituted piperazines. All synthesized compounds 3-14 were tested by using the method of twofold serial dilution technique for in vitro activities against certain strains of Gram-positive, Gram-negative bacteria as well as the yeasts Candida albicans, Candida krusei, and Candida glabrata in comparison with standard drugs. Microbiological results showed that the newly synthesized compounds possessed a broad spectrum of activity, showing MIC values of 3.12-50 mug/mL against the Candida species.
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Affiliation(s)
- Ozlem Temiz-Arpaci
- Ankara University, Faculty of Pharmacy, Department of Pharmaceutical Chemistry, Ankara, Turkey
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12
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Altenhoff G, Glorius F. A Domino Copper-Catalyzed CN and CO Cross-Coupling for the Conversion of Primary Amides into Benzoxazoles. Adv Synth Catal 2004. [DOI: 10.1002/adsc.200404182] [Citation(s) in RCA: 163] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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13
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Turan-Zitouni G, Demirayak S, Ozdemir A, Kaplancikli ZA, Yildiz MT. Synthesis of some 2-[(benzazole-2-yl)thioacetylamino]thiazole derivatives and their antimicrobial activity and toxicity. Eur J Med Chem 2004; 39:267-72. [PMID: 15051175 DOI: 10.1016/j.ejmech.2003.11.001] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2003] [Revised: 11/06/2003] [Accepted: 11/06/2003] [Indexed: 11/19/2022]
Abstract
Some 2-[(benzazole-2-yl)thioacetylamino]thiazole derivatives (III) were synthesized by reacting 4-methyl-2-(chloroacetylamino)thiazole derivatives (I) with benzazol-2-thiole (II) in acetone in the presence of K(2)CO(3). The chemical structures of the compounds were elucidated by (1)H NMR and FAB(+)-MS spectral data. The prepared compounds were tested for antimicrobial activity and toxicity.
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Affiliation(s)
- Gülhan Turan-Zitouni
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Anadolu University, 26470 Eskişehir, Turkey.
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14
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Yildiz-Oren I, Yalcin I, Aki-Sener E, Ucarturk N. Synthesis and structure–activity relationships of new antimicrobial active multisubstituted benzazole derivatives. Eur J Med Chem 2004; 39:291-8. [PMID: 15051178 DOI: 10.1016/j.ejmech.2003.11.014] [Citation(s) in RCA: 197] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2003] [Revised: 11/24/2003] [Accepted: 11/26/2003] [Indexed: 11/28/2022]
Abstract
A series of multisubstituted benzoxazoles, benzimidazoles, and benzothiazoles (5-7) as non-nucleoside fused isosteric heterocyclic compounds was synthesized and tested for their antibacterial activities against various Gram-positive and Gram-negative bacteria and antifungal activity against the fungus Candida albicans. Microbiological results indicated that the synthesized compounds possessed a broad spectrum of activity against the tested microorganisms at MIC values between 100 and 3.12 microg/ml. Structure-activity relationships (SAR) studies revealed that benzothiazole ring system enhanced the antimicrobial activity against Staphylococcus aureus. In these sets of non-nucleoside fused heterocyclic compounds electron withdrawing groups at position 5 of the benzazoles increased the activity against C. albicans.
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Affiliation(s)
- Ilkay Yildiz-Oren
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Ankara University, Tandogan, 06100 Ankara, Turkey
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15
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Sluis-Cremer N, Arion D, Parniak MA. Destabilization of the HIV-1 reverse transcriptase dimer upon interaction with N-acyl hydrazone inhibitors. Mol Pharmacol 2002; 62:398-405. [PMID: 12130693 DOI: 10.1124/mol.62.2.398] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
N-(4-tert-butylbenzoyl)-2-hydroxy-1-naphthaldehyde hydrazone (BBNH) inhibits both the DNA polymerase and ribonuclease H (RNase H) activities of the human immunodeficiency virus type 1 reverse transcriptase. In this study, we show that BBNH binding impacts on the stability of the human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) heterodimer. The Gibbs free energy of dimer dissociation of HIV-1 RT is decreased in the presence of increasing concentrations of BBNH, resulting in a loss in stability of 3.8 kcal mol(-1). To evaluate whether this observed phenomenon was mediated by BBNH binding to one or more sites in RT, we synthesized a variety of BBNH analogs and identified (4-t-butylbenzoyl)-2-hydroxy-1-salicylyl hydrazone (BBSH) and (4,N,N-dimethylaminobenzoyl)-2-hydroxy-1-naphthyl hydrazone as specific inhibitors of RT DNA polymerase or RT RNase H activity, respectively. Interestingly, only BBSH provided significant destabilization of the HIV-1 RT dimer. The identification of these specific inhibitors, in combination with other biochemical data, suggests a model in which two molecules of BBNH bind per RT heterodimer. In this regard, only the binding of hydrazone molecules in the DNA polymerase domain activity elicits the observed destabilization of the HIV-1 RT heterodimer.
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Affiliation(s)
- Nicolas Sluis-Cremer
- The University of Pittsburgh School of Medicine, Division of Infectious Diseases, Pittsburgh, Pennsylvania 15261, USA
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16
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Ünver H, Temiz Arpacı Ö, Mehmet Zengin D, Nuri Durlu T. Crystal structure, spectroscopic studies and conformational analyses of 5-chloro-6-nitro-2-cyclohexylmethylbenzoxazole. J Mol Struct 2002. [DOI: 10.1016/s0022-2860(01)00975-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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17
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Arpaci OT, Oren I, Altanlar N. Synthesis and antimicrobial activity of some novel 2-(p-substituted-phenyl)-5-substituted-carbonylaminobenzoxazoles. FARMACO (SOCIETA CHIMICA ITALIANA : 1989) 2002; 57:175-81. [PMID: 11989794 DOI: 10.1016/s0014-827x(01)01143-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of 2-(p-substituted-phenyl)-5-substituted-carbonylamino benzoxazole derivatives (5-22) was synthesized and their antimicrobial activities determined in comparison to several control drugs. The synthesized compounds were tested in vitro against Staphylococcus aureus, Streptococcus faecalis and Bacillus subtilis as Gram-positive, Pseudomonas aeruginosa and Escherichia coli as Gram-negative bacteria and the yeast Candida albicans. Microbiological results showed that the compounds possessed a diffuse spectrum of antibacterial activity against these microorganisms. Compound 9 which bears a phenylacetamido moiety at position 5 and a 4-fluorophenyl group at the 2-position of benzoxazole ring was the most active derivative against S. aureus, S. faecalis and P. aeruginosa with a MIC value of 12.5 microg/ml. Compound 11 provided higher potency than the other tested compounds against B. subtilis at a MIC value of 12.5 microg/ml. Compounds 5-22 showed antifungal activity against C. albicans with MIC values between 50 and 12.5 microg/ml.
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Affiliation(s)
- Ozlem Temiz Arpaci
- Ankara University, Faculty of Pharmacy, Department of Pharmaceutical Chemistry, Turkey.
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18
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Sener EA, Arpaci OT, Yalçin I, Altanlar N. Synthesis and microbiological activity of some novel 5-benzamido- and 5-phenylacetamido-substituted 2-phenylbenzoxazole derivatives. FARMACO (SOCIETA CHIMICA ITALIANA : 1989) 2000; 55:397-405. [PMID: 10983287 DOI: 10.1016/s0014-827x(00)00059-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The synthesis and microbiological activity of a new series of 5-benzamido- and 5-phenylacetamidosubstituted-2-phenylbenzoxazole derivatives (1-26) were described. The in vitro microbiological activity of the compounds was determined against Gram-positive, Gram-negative bacteria and the yeast Candida albicans in comparison with standard drugs. Microbiological results indicated that the synthesized compounds possessed a broad spectrum of activity against the tested microorganisms. The compounds 1, 21, 25 showed higher activity than tetracycline and streptomycin against Pseudomonas aeruginosa.
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Affiliation(s)
- E A Sener
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Ankara University, Tandoğan, Turkey.
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19
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Temiz O, Oren I, Sener E, Yalçin I, Uçartürk N. Synthesis and microbiological activity of some novel 5- or 6-methyl-2-(2,4-disubstituted phenyl) benzoxazole derivatives. FARMACO (SOCIETA CHIMICA ITALIANA : 1989) 1998; 53:337-41. [PMID: 9679283 DOI: 10.1016/s0014-827x(98)00030-5] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The synthesis of a new series of 5-or 6-methyl-2-(2,4-disubstituted phenyl) benzoxazoles (4, 5) is described in order to determine their antimicrobial activities and feasible structure-activity relationships. The synthesized compounds were tested in vitro against three Gram-positive bacteria, three Gram-negative bacteria and the yeast Candida albicans, in comparison with several control drugs. Microbiological results exhibited that the synthesized compounds possess a broad spectrum of antibacterial activity against the tested microorganisms. The compounds 4b and 4c indicated some antibacterial activity against Staphylococcus aureus having a minimum inhibitory concentration (MIC) of 12.5 micrograms/ml. Moreover, the compound 5a revealed a significant antibacterial activity against the enterobacter Pseudomonas aeruginosa showing a MIC value of 25 micrograms/ml, i.e. more potent than the control drugs tetracycline and streptomycin. For the antimycotic activity against the yeast C. albicans, the derivative 4c was found to be more active than the other synthesized compounds with a MIC value of 12.5 micrograms/ml, but one-fold less potent than the control drugs oxiconazole and haloprogin.
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Affiliation(s)
- O Temiz
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Ankara University, Turkey
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20
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Orlando P, Strazzullo G, Carretta F, De Falco M, Grippo P. Inhibition mechanisms of HIV-1, Mo-MuLV and AMV reverse transcriptases by Kelletinin A from Buccinulum corneum. EXPERIENTIA 1996; 52:812-7. [PMID: 8774754 DOI: 10.1007/bf01923995] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Kelletinin A [ribity pentakis (p-hydroxybenzoate)] (KA), an inhibitor of HTLV-1 replication isolated from Buccinulum corneum, showed a noncompetitive inhibitory activity with respect to the template primer and to dTTP in the poly(rA).oligo(dT)12-18-directed reaction of HIV-1, Mo-MuLV and AMV reverse transcriptases (RT). Analysis of natural and synthetic KA-related compounds showed that the inhibitory activity was strictly related to the structural peculiarities of the molecule. In the presence of DNA as template primer the inhibition mechanism was drastically modified: HIV-1 RT activity was stimulated by low concentrations of KA and was inhibited by increasing the concentration of the compound, while Mo-MuLV and AMV activities were irreversibly inhibited by the formation of a non-reactive complex. The RNase H activities of these RTs were not affected by KA. The results of this study suggest a different mechanism of interaction of Kelletinins with HIV-1 RT compared with other non-nucleoside inhibitors. A possible use of these drugs in combination therapy and in the design of structure-based reverse transcriptase inhibitors is discussed.
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Affiliation(s)
- P Orlando
- Istituto Biochimica delle Proteine ed Enzimologia, CNR, Arco Felice, Naples, Italy
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21
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Carroll SS, Benseler F, Olsen DB. Preparation and use of synthetic oligoribonucleotides as tools for study of viral polymerases. Methods Enzymol 1996; 275:365-82. [PMID: 9026650 DOI: 10.1016/s0076-6879(96)75022-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- S S Carroll
- Department of Antiviral Research, Merck Research Laboratories, West Point, Pennsylvania 19486, USA
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22
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Palaniappan C, Fay PJ, Bambara RA. Nevirapine alters the cleavage specificity of ribonuclease H of human immunodeficiency virus 1 reverse transcriptase. J Biol Chem 1995; 270:4861-9. [PMID: 7533167 DOI: 10.1074/jbc.270.9.4861] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The action of the dipyridodiazepinone nevirapine (BI-RG-587) on polymerization and RNase H activities of human immunodeficiency virus reverse transcriptase (RT) was examined. Substrates using heteropolymeric DNA primers hybridized to complementary RNA templates were employed. Challenged assays were performed that allowed measurement of activity of the RT resulting from a single round of binding of RT to substrate. Results demonstrated that nevirapine alters the cleavage specificity of the RNase H. Instead of a primary cleavage approximately 18 nucleotides upstream of the DNA 3' terminus, multiple cleavages were observed ahead of and behind this site. This indicated that the compound facilitates sliding of the RT away from the DNA primer terminus allowing cleavage at more sites. The change in specificity occurred whether the primer terminus was at the end or internal on the template. Experiments with RNA primers on circular DNA demonstrated a nevirapine-induced stimulation of RNase H activity beyond the increase expected from the change in cleavage specificity. Examination of polymerization showed that the compound decreased both the number of primers that underwent synthesis and the processive elongation of those primers. The significance of these results with respect to viral replication and recombination is discussed.
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Affiliation(s)
- C Palaniappan
- Department of Biochemistry, University of Rochester, New York 14642
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