- Iodine-catalyzed amination of benzothiazoles with KSeCN in water to access primary 2-aminobenzothiazoles
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A facile and sustainable approach for the amination of benzothiazoles with KSeCN using iodine as the catalyst in water has been disclosed under transition-metal free conditions. The reaction proceeded smoothly to afford various primary 2-amino benzothiazoles in up to 96% yield. A series of control experiments were performed, suggesting a ring-opening mechanism was involved via a radical process. This protocol provides efficient synthesis of primary 2-aminobenzothiazoles
- Zhu, Yu-Shen,Shi, Linlin,Fu, Lianrong,Chen, Xiran,Zhu, Xinju,Hao, Xin-Qi,Song, Mao-Ping
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supporting information
p. 1497 - 1500
(2021/09/09)
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- Copper-Catalyzed Thiolation of Terminal Alkynes Employing Thiocyanate as the Sulfur Source Leading to Enaminone-Based Alkynyl Sulfides under Ambient Conditions
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A highly efficient protocol for copper-catalyzed thio-alkynylation of enaminone-based thiocyanates with terminal alkynes under mild conditions has been developed. This scalable amino group-directed thio-alkynylation proceeds in the open air with a broad substrate scope and an excellent yield. The demonstrated synthetic transformation creates the opportunity for a wide variety of sulfur-containing useful materials. Gram-scale synthesis and further synthetic transformations of alkynyl sulfides highlight the potential utility of the method.
- Chandran,Pise, Ashwini,Shah, Suraj Kumar,Rahul,Suman,Tiwari, Keshri Nath
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supporting information
p. 6557 - 6561
(2020/08/24)
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- Proline-Based Allosteric Inhibitors of Zika and Dengue Virus NS2B/NS3 Proteases
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The NS2B/NS3 serine proteases of the Zika and Dengue flaviviruses are attractive targets for the development of antiviral drugs. We report the synthesis and evaluation of a new, proline-based compound class that displays allosteric inhibition of both proteases. The structural features relevant for protease binding and inhibition were determined to establish them as new lead compounds for flaviviral inhibitors. Based on our structure-activity relationship studies, the molecules were further optimized, leading to inhibitors with submicromolar IC50 values and improved lipophilic ligand efficiency. The allosteric binding site in the proteases was probed using mutagenesis and covalent modification of the obtained cysteine mutants with maleimides, followed by computational elucidation of the possible binding modes. In infected cells, antiviral activity against Dengue virus serotype 2 using prodrugs of the inhibitors was observed. In summary, a novel inhibitor scaffold targeting an allosteric site shared between flaviviral NS2B/NS3 proteases is presented whose efficacy is demonstrated in vitro and in cellulo.
- Millies, Benedikt,Von Hammerstein, Franziska,Gellert, Andrea,Hammerschmidt, Stefan,Barthels, Fabian,G?ppel, Ulrike,Immerheiser, Melissa,Elgner, Fabian,Jung, Nathalie,Basic, Michael,Kersten, Christian,Kiefer, Werner,Bodem, Jochen,Hildt, Eberhard,Windbergs, Maike,Hellmich, Ute A.,Schirmeister, Tanja
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p. 11359 - 11382
(2019/12/24)
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- Novel Triapine Derivative Induces Copper-Dependent Cell Death in Hematopoietic Cancers
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Triapine, an iron chelator that inhibits ribonucleotide reductase, has been evaluated in clinical trials for cancer treatment. Triapine in combination with other chemotherapeutic agents shows promising efficacy in certain hematologic malignancies; however, it is less effective against many advanced solid tumors, probably due to the unsatisfactory potency and pharmacokinetic properties. In this report, we developed a triapine derivative IC25 (10) with potent antitumor activity. 10 Preferentially inhibited the proliferation of hematopoietic cancers by inducing mitochondria reactive oxygen species production and mitochondrial dysfunction. Unlike triapine, 10 executed cytotoxic action in a copper-dependent manner. 10-Induced up-expression of thioredoxin-interacting protein resulted in decreased thioredoxin activity to permit c-Jun N-terminal kinase and p38 activation and ultimately led to the execution of the cell death program. Remarkedly, 10 showed good bioavailability and inhibited tumor growth in mouse xenograft models. Taken together, our study identifies compound 10 as a copper-dependent antitumor agent, which may be applied to the treatment of hematopoietic cancers.
- Chen, Ge,Niu, Chunyi,Yi, Jianhua,Sun, Lin,Cao, Hengyi,Fang, Yanjia,Jin, Taijie,Li, Ying,Lou, Chunli,Kang, Jingwu,Wei, Wanguo,Zhu, Jidong
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- Novel Triapine Derivative Induces Copper-Dependent Cell Death in Hematopoietic Cancers
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Triapine, an iron chelator that inhibits ribonucleotide reductase, has been evaluated in clinical trials for cancer treatment. Triapine in combination with other chemotherapeutic agents shows promising efficacy in certain hematologic malignancies; however, it is less effective against many advanced solid tumors, probably due to the unsatisfactory potency and pharmacokinetic properties. In this report, we developed a triapine derivative IC25 (10) with potent antitumor activity. 10 Preferentially inhibited the proliferation of hematopoietic cancers by inducing mitochondria reactive oxygen species production and mitochondrial dysfunction. Unlike triapine, 10 executed cytotoxic action in a copper-dependent manner. 10-Induced up-expression of thioredoxin-interacting protein resulted in decreased thioredoxin activity to permit c-Jun N-terminal kinase and p38 activation and ultimately led to the execution of the cell death program. Remarkedly, 10 showed good bioavailability and inhibited tumor growth in mouse xenograft models. Taken together, our study identifies compound 10 as a copper-dependent antitumor agent, which may be applied to the treatment of hematopoietic cancers.
- Chen, Ge,Niu, Chunyi,Yi, Jianhua,Sun, Lin,Cao, Hengyi,Fang, Yanjia,Jin, Taijie,Li, Ying,Lou, Chunli,Kang, Jingwu,Wei, Wanguo,Zhu, Jidong
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p. 3107 - 3121
(2019/04/01)
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- In vitro and in silico determination of glutaminyl cyclase inhibitors
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Alzheimer's disease (AD) is the most common form of neurodegenerative disease currently. It is widely accepted that AD is characterized by the self-assembly of amyloid beta (Aβ) peptides. The human glutaminyl cyclase (hQC) enzyme is characterized by assoc
- Tran, Phuong-Thao,Hoang, Van-Hai,Lee, Jeewoo,Hien, Tran Thi Thu,Tung, Nguyen Thanh,Ngo, Son Tung
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p. 29619 - 29627
(2019/10/02)
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- Synthesis and molecular docking of new roflumilast analogues as preferential-selective potent PDE-4B inhibitors with improved pharmacokinetic profile
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In the present work, we designed and synthesized new roflumilast analogues with preferential-selective PDE-4B inhibition activity and improved pharmacokinetic properties. The unsubstituted benzo[d]thiazol-2-yl and -6-yl benzamide derivatives (4a and 6a) showed both good potency and preferential selectivity for PDE-4B. More remarkably, 6c revealed 6 times preferential PDE-4B/4D selectivity with a significant increase of in vitro cAMP and good % inhibition of TNF-α concentration. In addition, the in vitro pharmacokinetics of 6c showed good metabolic stability with in vitro CLint (5.67 mL/min/kg) and moderate % plasma protein binding (53.71%). This was reflected onto increased in vivo exposure with a half-life greater than roflumilast by 3 folds (21 h) and a Cmax value of 113.958 ng/mL. Molecular docking attributed its good activity to its key binding interactions in PDE-4B active site with additional hydrogen bonding with amino acids lining the metal pocket. Summing up, 6c can be considered as suitable candidate for further investigation for the treatment of COPD.
- Moussa, Bahia A.,El-Zaher, Asmaa A.,El-Ashrey, Mohamed K.,Fouad, Marwa A.
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p. 477 - 486
(2018/02/28)
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- Design, synthesis, and AChE inhibitory activity of new benzothiazole–piperazines
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In the current study, 14 new benzothiazole–piperazine compounds were designed to meet the structural requirements of acetylcholine esterase (AChE) inhibitors. The target compounds were synthesised in three steps. Structures of the newly synthesised compounds (7–20) were confirmed using IR,1H NMR,13C NMR, and HRMS methods. The inhibitory potential of the compounds on AChE (E.C.3.1.1.7, from electric eel) was then investigated. Among the compounds, 19 and 20 showed very good activity on AChE enzyme. Kinetics studies were performed to observe the effects of the most active compounds on the substrate–enzyme relationship. Cytotoxicity studies, genotoxicity studies, and theoretical calculation of pharmacokinetics properties were also carried out. The compounds 19 and 20 were found to be nontoxic in both of the toxicity assays. A good pharmacokinetics profile was predicted for the synthesised compounds. Molecular docking studies were performed for the most active compounds, 19 and 20, and interaction modes with enzyme active sites were determined. Docking studies indicated a strong interaction between the active sites of AChE enzyme and the analysed compounds.
- Demir ?zkay, ümide,Can, ?zgür Devrim,Sa?l?k, Begüm Nurpelin,Acar ?evik, Ulviye,Levent, Serkan,?zkay, Yusuf,Ilg?n, Sinem,Atl?, ?zlem
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supporting information
p. 5387 - 5394
(2016/11/05)
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- Novel dengue virus NS2B/NS3 protease inhibitors
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Dengue fever is a severe, widespread, and neglected disease with more than 2 million diagnosed infections per year. The dengue virus NS2B/NS3 protease (PR) represents a prime target for rational drug design. At the moment, there are no clinical PR inhibitors (PIs) available. We have identified diaryl (thio)ethers as candidates for a novel class of PIs. Here, we report the selective and noncompetitive inhibition of the serotype 2 and 3 dengue virus PR in vitro and in cells by benzothiazole derivatives exhibiting 50% inhibitory concentrations (IC50s) in the low-micromolar range. Inhibition of replication of DENV serotypes 1 to 3 was specific, since all substances influenced neither hepatitis C virus (HCV) nor HIV-1 replication. Molecular docking suggests binding at a specific allosteric binding site. In addition to the in vitro assays, a cell-based PR assay was developed to test these substances in a replication-independent way. The new compounds inhibited the DENV PR with IC50s in the low-micromolar or submicromolar range in cells. Furthermore, these novel PIs inhibit viral replication at submicromolar concentrations.
- Wu, Hongmei,Bock, Stefanie,Snitko, Mariya,Berger, Thilo,Weidner, Thomas,Holloway, Steven,Kanitz, Manuel,Diederich, Wibke E.,Steuber, Holger,Walter, Christof,Hofmann, Daniela,Wei?brich, Benedikt,Spannaus, Ralf,Acosta, Eliana G.,Bartenschlager, Ralf,Engels, Bernd,Schirmeister, Tanja,Bodem, Jochen
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supporting information
p. 1100 - 1109
(2015/03/05)
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- Molecular modelling design, synthesis and cytotoxic evaluation of certain substituted 2-(3,4,5-triacetoxybenzoylamino)benzo[d]thiazole and 2-(galloylamino)benzo[d]thiazole derivatives having potential topoisomerase-I inhibitory activity
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New 2-(3,4,5-triacetoxybenzoylamino)benzothiazoles (4a~5f) and 2-(galloylamino)benzothiazoles (6a~7f), were designed as topoisomerase-I inhibitors. Compare/fit studies between these molecules and the generated topoisomerase-I inhibitors hypothesis reveale
- Ismail, Mohamed A. H.,Tratrat, Christophe,Haroun, Michelyne G.
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p. 1331 - 1345
(2013/12/04)
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- Fluorescence properties of 5-(5,6-dimethoxybenzothiazol-2-yl)-2′- deoxyuridine (dbtU) and oligodeoxyribonucleotides containing d btU
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We describe the synthesis and photophysical properties of 11 substituted 5-(benzothiazol-2-yl)-2′-deoxyuridine derivatives and oligodeoxyribonucleotides (ODNs) containing 5-(5,6-dimethoxybenzothiazol-2-yl)- 2′-deoxyuridine (dbtU), which was the strongest fluorescent derivative among those prepared. The fluorescence properties of dbtU itself and ODNs containing dbtU show the same tendency of being weaker in both neutral and acidic solution and stronger in basic solution. The ODNs (15mer) containing 16 combinations of 5′-XbtU-3′ and 5′-btUY-3′, where X, Y = A, T, G, or C, were synthesized, and their fluorescence intensity and quantum yield in basic solution were compared. On average, only the ODN with the 5′-G btU-3′ sequence shows a 7.9-fold lower fluorescence intensity than the other sequences. Ab initio calculations of 5′-G btU-3′ and 5′-btUG-3′ as models under basic conditions suggest that the lower fluorescence of the ODN containing the 5′-GbtU-3′ sequence is caused by a wider overlap between stacked guanine (Gua) and btUra than that of the 5′- btUG-3′ sequence and that the HOMO is delocalized not only on btUra but also on Gua.
- Hirose, Wataru,Sato, Kousuke,Matsuda, Akira
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experimental part
p. 6206 - 6217
(2011/12/02)
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- Selective detection of 5-formyl-2′-deoxyuridine, an oxidative lesion of thymidine, in DNA by a fluorogenic reagent
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Chemoselectivity in DNA: The thymidine lesion 5-formyl-2′- deoxyuridine (1) induces the mutation of DNA. Its derivatization with the specific fluorogenic reagent 2-amino-4,5-dimethoxythiophenol (2) gives 3, which shows strong fluorescence. This fast method for the detection of 1 requires no enzymatic digestion, HPLC separation, or MS analysis. ROS=reactive oxygen species.
- Hirose, Wataru,Sato, Kousuke,Matsuda, Akira
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supporting information; experimental part
p. 8392 - 8394
(2010/12/25)
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- The first potent inhibitors for human glutaminyl cyclase: Synthesis and structure-activity relationship
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The first effective inhibitors for human glutaminyl cyclase (QC) are described. The structures are developed by applying a ligand-based optimization approach starting from imidazole. Screening of derivatives of that heterocycle led to compounds of the imidazol-1-yl-alkyl thiourea type as a lead scaffold. A library of thiourea derivatives was synthesized, resulting in an inhibitory improvement by 2 orders of magnitude, leading to 1-(3-(1H-imidazol-1-yl)propyl)- 3-(3,4-dimethoxyphenyl)thiourea as a potent inhibitor. Systematic exploitation of the scaffold revealed a strong impact on the inhibitory efficacy and resulted in the development of imidazole-propyl-thioamides as another new class of potent inhibitors. A flexible alignment of the most potent compounds of the thioamide and thiourea class and a QC substrate revealed a good match of characteristic features of the molecules, which suggests a similar binding mode of both inhibitors and the substrate to the active site of QC.
- Buchholz, Mirko,Heiser, Ulrich,Schilling, Stephan,Niestroj, André J.,Zunkel, Katrin,Demuth, Hans-Ulrich
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p. 664 - 677
(2007/10/03)
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- Synthesis of APTRA derivatives as building blocks for low-affinity fluorescent Ca2+ indicators
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A new method for the synthesis of trialkyl aminophenoltriacetates (APTRA triesters) and the functionalization of these into suitable building blocks for potential fully conjugated low-affinity fluorescent Ca2+ indicators are described. Georg Th
- Metten, Bert,Smet, Mario,Boens, Noel,Dehaen, Wim
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p. 1838 - 1844
(2007/10/03)
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- Synthesis, in vitro and in vivo cytotoxicity, and prediction of the intestinal absorption of substituted 2-ethoxycarbonyl-imidazo[2,1-b]benzothiazoles
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The imidazobenzothiazole compounds 3-17 together with the imidazobenzoxazole 18, and the imidazobenzoimidazole 19 were prepared and their cytotoxic activity evaluated at the National Cancer Institute (NCI) for testing against a panel of approximately 60 tumor cell lines. Compounds 5, 7, 8, and 16 exhibited interesting in vitro cytotoxic activity. The most active imidazobenzothiazole derivative 8 was further evaluated as a cytotoxic agent in the hollow fiber assay and showed a score greater than the minimum values for xenograft testing together with a net cell kill. Comparison with the results displayed in the in vivo assay by standard antitumor drugs in clinical use revealed a significant in vivo activity of the benzothiazole compound. COMPARE analyses for compounds 4-19 against the NCI's standard agent database show poor or no correlation, and it might suggest for these compounds a mechanism of action unrelated to that of any known drug. Furthermore, the benzothiazole 8 did not show significant antitumor activity in a panel of two xenotransplanted tumors (i.e. colon and non-small cell lung tumors). By computing the polar surface area of compounds 3-19 with the MAREA computer program it was established that the most active compounds 5, 7, 8, and 16 should experience good intestinal permeability. Copyright
- Trapani, Giuseppe,Franco, Massimo,Latrofa, Andrea,Reho, Antonia,Liso, Gaetano
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p. 209 - 216
(2007/10/03)
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- Chemistry of Kojic Acid: One-Step Syntheses of Benzothiazoles and Other Fused Heterocycles from Kojic Acid Derivatives
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The reactions of the benzyl ether (1b) of kojic acid (1a) and its chloromethyl derivative (1c) were investigated as new routes to fused heterocyclic systems.The chloromethyl compound proved the more versatile intermediate yielding benzothiazoles with thio
- Teitei, Tsutomu
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p. 2307 - 2316
(2007/10/02)
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