Thiazole Groups Research Articles

Heteroaryldihydropyrimidine (HAP) and Sulfamoylbenzamide (SBA) Inhibit Hepatitis B Virus Replication by Different Molecular Mechanisms

Heteroaryldihydropyrimidine (HAP) and sulfamoylbenzamide (SBA) are promising non-nucleos(t)ide HBV replication inhibitors. HAPs are known to promote core protein mis-assembly, but the molecular mechanism of abnormal assembly is still elusive. Likewise, the assembly status of core protein induced by SBA remains unknown. Here we show that SBA, unlike HAP, does not promote core protein mis-assembly. Interestingly, two reference compounds HAP_R01 and SBA_R01 bind to the same pocket at the dimer-dimer interface in the crystal structures of core protein Y132A hexamer. The striking difference lies in a unique hydrophobic subpocket that is occupied by the thiazole group of HAP_R01, but is unperturbed by SBA_R01. Photoaffinity labeling confirms the HAP_R01 binding pose at the dimer-dimer interface on capsid and suggests a new mechanism of HAP-induced mis-assembly. Based on the common features in crystal structures we predict that T33 mutations generate similar susceptibility changes to both compounds. In contrast, mutations at positions in close contact with HAP-specific groups (P25A, P25S, or V124F) only reduce susceptibility to HAP_R01, but not to SBA_R01. Thus, HAP and SBA are likely to have distinctive resistance profiles. Notably, P25S and V124F substitutions exist in low-abundance quasispecies in treatment-naïve patients, suggesting potential clinical relevance.

Synthesis of PAMAM dendrimers with porphyrin core and functionalized periphery as templates of metal composite materials and their toxicity evaluation

Experiments were performed for the synthesis of meso-substituted tetraphenyl porphyrins in order to obtain growth active points for PAMAM branches and a functionalized periphery with thiazole groups for increasing the metal complexation activity. Characterization by 1H and 13C NMR, mass spectrometry and infrared spectrometry confirmed the produced dendrimeric nanostructures; the chemical reduction of metallic Ag and Cu inside the dendrimer was proved by XPS. Finally, the toxicity of the metal-dendrimer complex was analyzed by means of the bacterial respiration test.

Thienothiophene-based copolymers for high-performance solar cells, employing different orientations of the thiazole group as a π bridge

The new strategy, employing thiazole as a π bridge into the backbone of quinoid polymers, enhanced the VOC and photovoltaic performance.

ANTIMICROBIAL EVALUATION OF MALEIMIDE MONOMERS, HOMOPOLYMERS AND COPOLYMERS CONTAINING AZO, SULPHONAMIDE AND THIAZOLE GROUPS

New maleimide Monomers, homopolymers and copolymers containing azo, sulfonamide and thiazole groups were synthesized. The structures of newly synthesized compounds have been characterized on the basis of their spectroscopic data (FT-IR and 1H-NMR). Antimicrobial studies of synthesized compounds were performed using agar well diffusion method. All the compounds showed pronounced activity against bacterial strains in comparison to activity against fungal strains.The highest antibacterial potency was exhibited by the homopolymer HPSPMI against Escherichia coli, Klebsiella pneumoniae and Bacillus subtilis. The activity of HPSPMI against later two was more pronounced than the standard drug used. Only Selected compounds showed antifungal activity. Appreciable results were found against Aspergillus fumigates but not with Candida albicans. HPSPMI showed highest activity against Aspergillus fumigates. Surprisingly after homo and copolymerization, maximum compounds exhibited not only pronounced antibacterial activity but also antifungal activity.

A highly selective and sensitive chemosensor derived coumarin–thiazole for colorimetric and fluorimetric detection of CN− ion in DMSO and aqueous solution: synthesis, sensing ability, Pd(II)/Pt(II) complexes and theoretical studies

A colorimetric and fluorescence turn-on cyanide probe, including coumarin–thiazole and imine (azomethine) group, has been designed and synthesized. It showed an immediate visible color change from yellow to deep red only in DMSO, and an appearance of strong yellow and green fluorescence when CN− was added to DMSO, and a mixture of DMSO:H2O (9:1), respectively. Thus, the sensor can be used to detect CN− in aqueous solution. The sensing mechanism of chemosensor 4 reactions with CN− ion was observed with the deprotonation and addition mechanisms at the same time. The mechanisms of reactions of chemosensor 4 with; CN−, F−, and AcO− were examined using 1H NMR spectroscopy, and were also theoretically supported by DFT and TD-DFT calculations. In addition, the metal complexes of chemosensor 4 with Pd(II) and Pt(II) were also synthesized and all the synthesized compounds were characterized using general spectroscopic methods (FTIR, 1H/13C NMR, and mass spectrometry), magnetic susceptibilities, and conductivity measurements. Also, the molecular structure of 4 was determined using single crystal X-ray analysis.

Preparation and Thermal Property of Epoxy Resin Containing Aromatic Thiazole Groups

Preparation and Thermal Property of Epoxy Resin Containing Aromatic Thiazole Groups

Synthesis, structural characterization, and DFT calculations of 3-buthyl-4-(3-methyl-3-mesitylcyclobut-1-yl)-1,3-thiazole-2(3H)-thione

The title compound, C21H29NS2, has been synthesized and its crystal structure has been determined from single crystal X-ray diffraction data. Crystals are monoclinic, a = 11.4923(8), b = 13.1842(7), c = 14.6583(8) A, β = 109.983(6)°, sp. gr. P21/c, Z = 4. Mesityl and thiazole groups are in cis positions with respect to the cyclobutane ring. The cyclobutane ring is puckered, with a dihedral angle of 26.6(2)° between the two three-atom planes. The crystal structure involves one weak intermolecular C–H···S hydrogen-bond. The molecular geometry was also optimized using density functional theory (DFT/B3LYP) method with the 6-311G(d, p) basis set in ground state. Geometric parameters (bond lengths, bond angles and torsion angles) and vibrational assignments have been calculated theoretically and compared with the experimental data.

Synthesis of porphyrin sensitizers with a thiazole group as an efficient π-spacer: potential application in dye-sensitized solar cells

CNU-OC8 exhibits better photovoltaic performance than the benchmark YD2-OC8 sensitizer in a liquid I−/I3− redox electrolyte.

Synthesis of carbazole-based copolymers containing carbazole-thiazolo[5,4-d]thiazole groups with different dopants and their fluorescence and electrical conductivity applications

The electrical conductivity of poly(carbazole-thiazolo[5,4-d]thiazole) was measured with the introduction of five different dopants (HCl, Fe(iii), Cu(ii), H3BO3, and I2) into its framework through protonation of a nitrogen atom or complex formation.

Synthesis of thiazole silica hybrid from waste glass for adsorption of cadmium(II)

Synthesis of thiazole silica hybrid from waste glass to adsorption of cadmium (II) metal ion has been performed. The synthesis was done by attaching thiazole group through liaison compound γ- glycidoxy propyl tri-methoxy silane with silica gel obtained from waste glass. In this study, the effect of adsorption contact time and the concentration of cadmium (II) was studied to determine the reaction rate and the amount of adsorption thermodynamics. The existence of the cluster thiazole on silica gel indicated by IR spectra at wavelengths around 2576 cm-1 of mercaptan groups that previously did not appear on silica gel without modification. The synthesized TSH showed a high adsorption capacity of 9.363 mmol/g of Cd(II). The adsorption isotherm obtained with Langmuir isotherm model gives the negative values of ΔG°, i.e. -15.488 kJ/mol for Cd(II), indicating the spontaneous process of adsorption. Kinetic studies showed that the adsorption of Cd(II) ion into TSH follows the pseudo-second-order kinetics.

Electrochemical, spectroelectrochemical characterization and electropolymerization of 2-(4-methyl-1,3-thiazol-5-yl)ethoxy-substituted manganese and indium phthalocyanines

In this study, the synthesis of novel, symmetrical, tetrasubstituted metallo-phthalocyanines (MPc; M=manganese, indium) bearing four 2-(4-methyl-1,3-thiazol-5-yl) ethoxy units has been reported. All of the synthesized compounds have been characterized by using elemental analysis, UV–Vis, FT-IR and MS spectroscopic data. Electrochemical, spectroelectrochemical and electropolymerization properties of the phthalocyanines were studied by cyclic voltammetry. Electrochemistry and spectroelectrochemistry of metallophthalocyanines (MPc) bearing redox active and polymerizable thiazole groups were introduced. InIIIClPc gave only Pc ring based reduction process, metal based and Pc based redox processes were observed for during the cathodic potential scans. However both complexes were coated on the working electrode during the oxidation reactions due to the oxidative electropolymerization of thiazole groups on the substituents of the complexes. Thiazole groups were oxidized at around 1.50V, which triggered cationic electropolymerization reactions of the complexes. Type of the metal centers, working electrode, and solvent of the electrolytes and potential range and scan rate of the CV measurements affected the electropolymerization mechanisms of the complexes.

Substituent effects on the photochromic properties of benzothiophene-based derivatives.

Five diarylethene photochromic derivatives, the structures of which incorporate a central benzothiophene unit, a left-hand thiazole group, and a right-hand benzothiophene group, have been prepared. The compound with a thiazole unit with no substituent on the reaction-center carbon atom reveals an unprecedented transformation upon light irradiation. When the 4-position of thiazole is protected by a methyl group, the compounds show high photosensitivity and photochromic properties. In this case, light irradiation affords new compounds with [5]helicene structures featuring the highest redshifted absorption maxima reported to date.

Antimicrobial polymethacrylates based on quaternized 1,3-thiazole and 1,2,3-triazole side-chain groups

Increasing antimicrobial and non-hemotoxic characteristics of polymers bearing thiazole and triazole groups by the appropriate selection of spacer and quaternization groups.

Sydnone Sulfonamide Derivatives as Antibacterial, Antifungal, Antiproliferative and Anti-HIV Agents

Three series of substituted sydnone sulfonamide derivatives were synthesized wherein 3-(4-methylphenyl)-4-(chlorosulfonyl)sydnone (5) was linked by a sulfonamide linkage with various thiazole, benzothiazole and quinazoline groups. The structures of the compounds were confirmed by IR and NMR spectroscopy and elemental analysis. The synthesized compounds were evaluated for their antibacterial, antifungal, antiproliferative and anti-HIV activities. Anti-HIV activity was determined against human immunodeficiency virus HIV-1 (III-B) and HIV-2 (ROD) in MT-4 cells. Inhibition of cytomegalovirus and varicella-zoster virus (VZV) replication was measured in human embryonic lung (HEL) cells.

Metal complexes of biological active 2-aminothiazole derived ligands

The most imperative outcomes of extensive sterdies (synthesis, spectral, structural characterization and biological applications) of metal complexes with thiazole derived ligands are reviewed. A large number of coordination compounds are known but still there is a need of new compounds to develop various efforts in different fields for biomedical applications. The synthesis of Schiff base ligands is very important, and it has recently drawn the attention of numerous research groups, making this area constantly evolve. Authors are also synthesizing some novel biologically potent ligands and their unique complexes and complexes found more biological active agents than that of ligands against bacteria, fungi and herbs. Highlights: Schiff bases and their metal chelates catalyze reactions; Schiff bases derived from sulfane thiadiazole show toxicities against insects; Schiff bases of thiadiazole have good plant regulator activity; Phenyl ring attached to the thiazole group showed interesting structure activity.

Inhibitors of Alzheimer's BACE-1 with 3,5-bis-N-(aryl/heteroaryl) carbamoyl-4-aryl-1,4-dihydropyridine structure.

β-site amyloid precursor protein cleaving enzyme (BACE-1) is a validated target for Alzheimer therapy due to its distinctive role in pathogenesis of AD. In the present contribution, a series of new 3,5-bis-N-(aryl/heteroaryl) carbamoyl-4-aryl-1,4-dihydropyridine structures were synthesized as BACE-1 inhibitors (6a-6n). In vitro BACE-1 inhibitory activities were determined by enzymatic fluorescence resonance energy transfer assay. Synthesized dihydropyridine (DHP) analogues exhibited weak to good inhibitory activities while 6i, 6n and 6a were found to be the most potent molecules with 83.76, 79.45 and 72.47% BACE-1 inhibition at 10μM, respectively. Structure binding/activity relationship elucidations revealed that superior BACE-1 inhibitory activities were observed for DHP derivatives bearing fused/non-fused thiazole groups and particularly 3,5-bis-N-(6-ethoxy-2-benzothiazolyl) moiety. Binding maps showed that enhanced activity may be attributed to the additional H-bond and hydrophobic interactions with S2-S3 subpockets of BACE-1.

Enzymatic synthesis of epothilone A glycosides

Epothilones are extremely cytotoxic chemotherapeutic agents with epoxide, thiazole, and ketone groups that share equipotent kinetic similarity with taxol. The in vitro glycosylation catalyzed by uridine diphosphate glucosyltransferase (YjiC) from Bacillus licheniformis generated six novel epothilone A glycoside analouges including epothilone A 7-O-β-D-glucoside, epothilone A 7-O-β-D-galactoside, epothilone A 3,7-O-β-D-digalactoside, epothilone A 7-O-β-D-2-deoxyglucoside, epothilone A 7-O-β-L-rhamnoside, and epothilone A 7-O-β-L-fucoside. Epothilone A 7-O-β-D-glucoside was structurally elucidated by ultra-high performance liquid chromatography-photo diode array (UPLC-PDA) conjugated with high resolution quantitative time-of-flight-electrospray ionization mass spectroscopy (HR-QTOF ESI-MS/MS) supported by one-and two-dimensional nuclear magnetic resonance studies whereas other epothilone A glycosides were characterized by UPLC-PDA and HR-QTOF ESI-MS/MS analyses. The time dependent conversion study of epothilone A to epothilone A 7-O-β-D-glucoside found to be maximum (~26%) between 3 h to 5 h incubation.

Design, Synthesis, and Biological Evaluation of (S)‐Valine Thiazole‐Derived Cyclic and Noncyclic Peptidomimetic Oligomers as Modulators of Human P‐Glycoprotein (ABCB1)

Multidrug resistance caused by ATP binding cassette transporter P-glycoprotein (P-gp) through extrusion of anticancer drugs from the cells is a major cause of failure in cancer chemotherapy. Previously, selenazole-containing cyclic peptides were reported as P-gp inhibitors and were also used for co-crystallization with mouse P-gp, which has 87 % homology to human P-gp. It has been reported that human P-gp can simultaneously accommodate two to three moderately sized molecules at the drug binding pocket. Our in silico analysis, based on the homology model of human P-gp, spurred our efforts to investigate the optimal size of (S)-valine-derived thiazole units that can be accommodated at the drug binding pocket. Towards this goal, we synthesized varying lengths of linear and cyclic derivatives of (S)-valine-derived thiazole units to investigate the optimal size, lipophilicity, and structural form (linear or cyclic) of valine-derived thiazole peptides that can be accommodated in the P-gp binding pocket and affects its activity, previously an unexplored concept. Among these oligomers, lipophilic linear (13) and cyclic trimer (17) derivatives of QZ59S-SSS were found to be the most and equally potent inhibitors of human P-gp (IC50 =1.5 μM). As the cyclic trimer and linear trimer compounds are equipotent, future studies should focus on noncyclic counterparts of cyclic peptides maintaining linear trimer length. A binding model of the linear trimer 13 within the drug binding site on the homology model of human P-gp represents an opportunity for future optimization, specifically replacing valine and thiazole groups in the noncyclic form.

Synthesis and Properties of a Novel Unsymmetrical Diarylethene with a Benzothiophene and a Thiazole Group

A new unsymmetrical photochromic diarylethene1o, which is named 1-(2-methyl-benzothiophene)-2-(2,4-dimethyl-5-thiazoly) perfluorocyclopentene, was synthesized. In the meantime, its photochromic, kinetics and fluorescence properties were investigated in detail. The result indicated that this diarylethene had good thermal stability and exhibited reversible photochromism, changing the color from colorless to orange in hexane solution upon appropriate irradiation with 297 nm UV light, respectively. What is more, the kinetic experiments illustrated that the cyclization/cycloreversion process of this compound was determined to be the zeroth/first reaction. The fluorescence intensity of diarylethene decreased dramatically along with the photochromism from open-ring isomer to closed-ring isomer upon irradiation with UV light in hexane solution. In addition, the results demonstrated that the unsymmetrical diarylethene compound1o, which we have synthesized, had attractive properties for potential application in optical storage.

Synthesis and photophysics of new metallo phthalocyanine complexes with thiazole groups and their fluorescence quenching studies with benzoquinone

The synthesis of novel, symmetrical, tetra substituted metallo-phthalocyanines (cobalt, zinc and copper) bearing four 2-(4-methyl-1,3-thiazol-5-yl)ethoxy units was reported. The reaction of 2-(4-methyl-1,3-thiazol-5-yl)ethanol with 4-nitrophthalonitrile in the presence of K2CO3 led to formation of 4-[2-(4-methyl-1,3-thiazol-5-yl)ethoxy]phthalonitrile. Co and Zn phthalocyanines were synthesized using microwave irradiation from the corresponding phthalonitrile compound and metal salts (CoCl2 and Zn(CH3COO)2) in hexanol in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). Cu phthalocyanine was obtained by heating the phthalonitrile derivative and copper (II) chloride at 160°C in n-hexanol in the presence of DBU. The resulting products were purified by column chromatography and characterized by several chemical and spectroscopic analysis methods. Photophysical properties with zinc (II) phthalocyanine were found, including electronic absorption and fluorescence quantum yield. The fluorescence of the complexes was investigated in DMF and it was found that benzoquinone (BQ) was an effective quencher.