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Targeting triple-negative breast cancer cells with 6,7-bis(hydroxymethyl)-1H,3H-pyrrolo[1,2-c]thiazoles

Santos, Kathleen; Laranjo, Mafalda; Abrantes, Ana Margarida; Brito, Ana F.; Gonçalves, Cristina; Ribeiro, Ana Bela Sarmento; Botelho, M. Filomena; Soares, Maria I. L.; Oliveira, Andreia S. R.; Melo, Teresa M. V. D. Pinho e
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
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Further studies on 6,7-bis(hydroxymethyl)-1H,3H-pyrrolo[1,2-c]thiazoles as anticancer agents against breast cancer are reported, allowing to demonstrate the potential of these compounds for the therapy of the triple-negative breast cancer, the most challenging tumors in clinical practice. These compounds were assayed for their in vitro cytotoxicity on several human breast cancer cell lines (MCF7, HCC1954 and HCC1806 cell lines). Particularly interesting were the results obtained for 4-hydroxyphenyl substituted derivative, which proved to be the most promising compound regarding HCC1806 cell line, a triple-negative breast cancer. The effects of the two most active compounds on cell survival, viability, cell cycle, DNA damage and expression of proteins related to cell death pathways were studied. The reported results consolidate the potential of 6,7-bis(hydroxymethyl)-1H,3H-pyrrolo[1,2-c]thiazoles for the therapy of breast cancer, particularly the triple-negative.

Preparation of a clay-modified carbon paste electrode based on 2-thiazoline-2-thiol-hexadecylammonium sorption for the sensitive determination of mercury

Dias Filho, Newton L.; Do Carmo, Devaney R.; Gessner, Fergus; Rosa, André H.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 1309-1316
ENG
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A montmorillonite from Wyoming-USA was used to prepare an organo-clay complex, named 2-thiazoline-2-thiol-hexadecyltrimethylammonium-clay (TZT-HDTA-clay), for the purpose of the selective adsorption of the heavy metals ions and possible use as a chemically modified carbon paste electrode (CMCPE). Adsorption isotherms of Hg 2+, Pb 2+, Cd 2+, Cu 2+, and Zn 2+ from aqueous solutions as a function of the pH were studied at 298 K. Conditions for quantitative retention and elution were established for each metal by batch and column methods. The organo-clay complex was very selective to Hg(II) in aqueous solution in which other metals and ions were also present. The accumulation voltammetry of Hg(II) was studied at a carbon paste electrode chemically modified with this material. The mercury response was evaluated with respect to the pH, electrode composition, preconcentration time, mercury concentration, cleaning solution, possible interferences and other variables. A carbon paste electrode modified by TZT-HDTA-clay showed two peaks: one cathodic peak at about 0.0 V and an anodic peak at 0.25 V, scanning the potential from -0.2 to 0.8 V (0.05 M KNO 3 vs. Ag/AgCl). The anodic peak at 0.25 V presents excellent selectivity for Hg(II) ions in the presence of foreign ions. The detection limit was estimated as 0.1 μg L -1. The precision of determination was satisfactory for the respective concentration level. 2005 © The Japan Society for Analytical Chemistry.

Cytotoxic effects of different concentrations of chlorhexidine

Souza, Lorena Brito de; Aquino, Sabrina García de; Souza, Pedro Paulo Chaves de; Hebling, Josimeri; Costa, Carlos Alberto de Souza
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 400-404
ENG
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Purpose: To evaluate the cytotoxic effects of different concentrations of Chlorhexidine (Chx) to the odontoblast cell line MDPC-23. Methods: The odontoblast-like cells were seeded (30,000 cells/cm 2) in 60 wells of 24-well dishes and then incubated in contact with the following experimental and control solutions: Group 1: 0.0024% Chx; Group 2: 0.004% Chx; Group 3: 0.02% Chx; Group 4: Phosphate buffer saline solution (PBS, negative control); and Group 5: 0.06% H 2O 2 (positive control). Cell metabolic activity was measured by MTT assay and the cell morphology was analyzed by SEM. Results: The cytotoxic effects of Chx are dose-dependent. The reduction in the cell metabolism for Groups 1, 2, and 3 was 24.8%, 29.9% and 70.8%, respectively. No statistical difference was observed between the Groups 1 and 2 in which no significant cell morphology changes occurred. Consequently, it was concluded that 0.02% Chx solution presents high cytotoxicity to the odontoblast-like cells MDPC-23. On theother hand, 0.0024% and 0.004% Chx causes slight cytopathic effects to the cultured cells.

In vitro effect of low-level laser therapy on typical oral microbial biofilms

Basso, Fernanda G.; Oliveira, Camila F.; Fontana, Amanda; Kurachi, Cristina; Bagnato, Vanderlei S.; Spolidório, Denise M. P.; Hebling, Josimeri; de Souza Costa, Carlos A.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 502-510
ENG
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The aim of this study was to evaluate the effect of specific parameters of low-level laser therapy (LLLT) on biofilms formed by Streptococcus mutans, Candida albicans or an association of both species. Single and dual-species biofilms - SSB and DSB - were exposed to laser doses of 5, 10 or 20 J/cm 2 from a near infrared InGaAsP diode laser prototype (LASERTable; 780 ± 3 nm, 0.04 W). After irradiation, the analysis of biobilm viability (MTT assay), biofilm growth (cfu/mL) and cell morphology (SEM) showed that LLLT reduced cell viability as well as the growth of biofilms. The response of S. mutans (SSB) to irradiation was similar for all laser doses and the biofilm growth was dose dependent. However, when associated with C. albicans (DSB), S. mutans was resistant to LLLT. For C. albicans, the association with S. mutans (DSB) caused a significant decrease in biofilm growth in a dose-dependent fashion. The morphology of the microorganisms in the SSB was not altered by LLLT, while the association of microbial species (DSB) promoted a reduction in the formation of C. albicans hyphae. LLLT had an inhibitory effect on the microorganisms, and this capacity can be altered according to the interactions between different microbial species.

Acute aerocystitis in Piaractus mesopotamicus: Participation of eicosanoids and pro-inflammatory cytokines

Claudiano, Gustavo da Silva; Petrillo, Thalita R.; Manrique, Wilson G.; Castro, Marcello P.; Loureiro, Bruna A.; Marcusso, Paulo F.; Belo, Marco A.A.; Moraes, Julieta R.E.; De Moraes, Flávio Ruas
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 1057-1062
ENG
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26.24%
A total of 360 pacus (Piaractus mesopotamicus) were used to study vascular permeability (VP) and inflammatory cell component (CC) in induced aerocystitis in P. mesopotamicus through inoculation of inactivated Aeromonas hydrophila, and the effect of steroidal and nonsteroidal anti-inflammatory drugs. It was observed that after inoculation of A. hydrophila, the maximum VP occurred 180 min post-stimulus (MPS). Pretreatment with anti-inflammatory drugs inhibited VP, and the inhibitory effect of dexamethasone was seen earlier than the effects caused by meloxicam and indomethacin. Inoculation of the bacterium caused a gradual increase in the accumulation of cells, which reached a maximum 24 h post-stimulus (HPS). Pretreatment with dexamethasone, indomethacin and meloxicam reduced the accumulation of lymphocytes, thrombocytes, granulocytes and macrophages. There was no significant difference between the different doses of the drugs tested. The results suggest that eicosanoids and pro-inflammatory cytokines participate in chemical mediation in acute inflammation in pacus. © 2013 Elsevier Ltd.

Synthesis and evaluation of thermal, electrochemical and nonlinear optical properties of dicyano- and tricyanovinyl-bithienylpyrroles

Fonseca, A. Maurício C.; Castro, M. Cidália R.; Belsley, M.; Raposo, M. Manuela M.
Fonte: MOLMAT 2012 Publicador: MOLMAT 2012
Tipo: Conferência ou Objeto de Conferência
Publicado em //2012 ENG
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Materials exhibiting large optical nonlinearities continue to be the subject of intense studies because of their potential applications in modern communication technologies involving optical data processing, transmission, or storage, where they are gradually replacing classical electronic devices.[1] Earlier we reported on the synthesis and evaluation of thermal, redox and NLO properties of donor-acceptor substituted thienylpyrrole derivatives. Our studies have shown that replacing the benzene ring of a chromophore bridge with heterocycles (thiophene, pyrrole, (benzo)thiazole), results in an enhanced molecular hyperpolarizability of conjugated donor–acceptor compounds.[2,3,4,5,6] As part of an on-going program to develop strong charge transfer donor-acceptor pyrrole systems with enhanced nonlinear optical (NLO) properties we have explored the potential of bithienyl-pyrrole derivatives 1-4 as efficient π-conjugated systems functionalized with dicyanovinyl- or tricyanovinyl- acceptor groups substituted at thiophene or pyrrole rings. Compounds 3a-b were prepared, in good yields, through Knoevenagel condensation of the precursor aldehydes 2a-b with malononitrile, and the tricyano derivative 4 were synthesized through direct tricyanovinylation reaction of 1 with tetracyanoethylene. On the other hand...

In vitro efficacy of nitro- and bromo-thiazolyl-salicylamide compounds (thiazolides) against Besnoitia besnoiti infection in Vero cells

CORTES, H. C. E.; MUELLER, N.; ESPOSITO, M.; LEITÃO, A.; NAGULESWARAN, A.; HEMPHILL, A.
Fonte: Universidade de Évora Publicador: Universidade de Évora
Tipo: Artigo de Revista Científica
POR
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Nitazoxanide (NTZ) and its deacetylated metabolite tizoxanide (TIZ) exhibit considerable in vitro activity against Besnoitia besnoiti tachyzoites grown in Vero cells. Real-time-PCR was used to assess B. besnoiti tachyzoite adhesion, invasion, and intracellular proliferation in vitro. A number of NTZ-derivatives, including Rm4822 and Rm4803, were generated, in which the thiazole-ring-associated nitro-group was replaced by a bromo-moiety. We here show that replacement of the nitro-group on the thiazole ring with a bromo (as it occurs in Rm4822) does not impair the efficacy of the drug, but methylation of the salicylate ring at the ortho-position in a bromo-derivative (Rm4803) results in complete abrogation of the antiparasitic activity. Treatment of extracellular B. besnoiti tachyzoites with NTZ has an inhibitory effect on host cell invasion, while treatments with TIZ, Rm4822 do not.TEMdemonstrates that the effects of Rm4822 treatment upon the parasites are similar to the damage induced by NTZ. This includes increased vacuolization of the parasite cytoplasm, and loss of the structural integrity of the parasitophorous vacuole and its membrane. Thus, Rm4822, due to the absence of a potentially mutagenic nitro-group, may represent an important potential addition to the anti-parasitic arsenal for food animal production...

A pyrazolyl-thiazole derivative causes antinociception in mice

Prokopp,C.R.; Rubin,M.A.; Sauzem,P.D.; de Souza,A.H.; Berlese,D.B.; Lourega,R.V.; Muniz,M.N.; Bonacorso,H.G.; Zanatta,N.; Martins,M.A.P.; Mello,C.F.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2006 EN
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The present study investigates the antinociceptive effect of the pyrazolyl-thiazole derivative 2-(5-trichloromethyl-5-hydroxy-3-phenyl-4,5-dihydro-1 H-pyrazol-1-yl)-4-(4-bromophenyl)-5-methylthiazole (B50) in mice. Male albino Swiss mice (30-40 g) were used in the acetic acid-induced abdominal writhes and tail-immersion tests. B50 caused dose-dependent antinociception (8, 23 and 80 µmol/kg, sc) in the acetic acid writhing assay (number of writhes: vehicle: 27.69 ± 6.15; B50 (8 µmol/kg): 16.92 ± 3.84; B50 (23 µmol/kg): 13.85 ± 3.84; B50 (80 µmol/kg): 9.54 ± 3.08; data are reported as means ± SEM for 9 animals per group). On the other hand, B50 did not cause antinociception in the tail immersion assay. Naloxone (2.75 µmol/kg, sc) prevented B50-induced antinociception (number of writhes: vehicle-saline: 31.11 ± 3.15; vehicle-naloxone: 27.41 ± 3.70; B50 (80 µmol/kg)-saline: 8.70 ± 3.33; B50 (80 µmol/kg)-naloxone: 31.84 ± 4.26; morphine-saline: 2.04 ± 3.52; morphine-naloxone: 21.11 ± 4.26; 8-9 animals per group). The removal of the methyl group of the thiazole ring of B50 or substitution of the bromo substituent with the methyl at position 4 of the phenyl group, which is attached to the thiazole ring of B50, resulted in loss of activity...

Growth Inhibition by Hexoses of a Temperature-Sensitive Thiazoleless Mutant of Salmonella typhimurium

Parada, Jose L.; Ortega, Manuel V.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /09/1967 EN
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A Salmonella typhimurium mutant showing impairment in the utilization of hexoses was isolated after treatment with N-methyl-N′-nitro-N-nitrosoguanidine. At 30 C, it grew with hexoses (glucose, fructose, galactose, mannitol), glycerol, succinate, or acid-hydrolyzed casein. At 37 C, it failed to grow with any of the hexoses. Enzymatic determinations demonstrated, however, that the enzymes of the glycolytic pathway (up to the formation of triose phosphates) were present and active at 25 and 32 C. At 42 C, the mutant did not grow with any of the carbon sources used. At both 37 and 42 C, the mutant grew perfectly well with hexoses if yeast extract was present. The metabolite required for growth was thiamine or, specifically, its thiazole moiety. If glucose was added to a culture growing in glycerol, at 37 C, growth was inhibited. This inhibition was relieved by the addition of thiamine or thiazole. Thus, at 37 C and only in the presence of hexoses, the mutant manifests a requirement for thiazole. This auxotrophy is absolute at 42 C. These data indicate that, in this mutant, some derivative of hexoses inhibits the synthesis of thiazole, and that this inhibition is also dependent on the temperature of incubation. The position in the bacterial chromosome of the genetic locus of this lesion (thz−) was determined by conjugation and found to coincide with the only thiamine (thi) locus so far reported.

Biosynthesis of the Thiamin Thiazole in Eukaryotes: The Conversion of NAD to an Advanced Intermediate

Chatterjee, Abhishek; Jurgenson, Christopher T.; Schroeder, Frank C.; Ealick, Steven E.; Begley, Tadhg P.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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Thiazole synthase catalyzes the formation of the thiazole moiety of thiamin pyrophosphate. The enzyme from Saccharomyces cerevisiae (THI4) copurifies with a set of strongly bound adenylated metabolites. One of them has been characterized as the ADP adduct of 5-(2-hydroxyethyl)-4-methylthiazole-2-carboxylic acid. Attempts towards yielding active wild type Thi4 by releasing protein-bound metabolites have failed so far. Here we describe the identification and characterization of two partially active mutants (C204A and H200N) of THI4. Both mutants catalyzed the release of the nicotinamide moiety from NAD to produce ADP-ribose, which was further converted to ADP-ribulose. In the presence of glycine, both the mutants catalyzed the formation of an advanced intermediate. The intermediate was trapped with ortho-phenylenediamine yielding a stable quinoxaline derivative, which was characterized by NMR spectroscopy and ESI-MS. These observations confirm NAD as the substrate for THI4 and elucidate the early steps of this unique biosynthesis of the thiazole moiety of thiamin in eukaryotes.

Pharmacokinetic Optimization of 4-Substituted Methoxybenzoyl-aryl-thiazole and 2-Aryl-4-benzoyl-imidazole for Improving Oral Bioavailability

Li, Chien-Ming; Chen, Jianjun; Lu, Yan; Narayanan, Ramesh; Parke, Deanna N.; Li, Wei; Ahn, Sunjoo; Miller, Duane D.; Dalton, James T.
Fonte: The American Society for Pharmacology and Experimental Therapeutics Publicador: The American Society for Pharmacology and Experimental Therapeutics
Tipo: Artigo de Revista Científica
Publicado em /10/2011 EN
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Microtubules are critical components of the cytoskeleton. Perturbing their function arrests the growth of a broad spectrum of cancer cell lines, making microtubules an excellent and established target for chemotherapy. All of the U.S. Food and Drug Administration-approved antitubulin agents bind to paclitaxel or vinblastine binding sites in tubulin. Because of the complexity of their structures, it is difficult to structurally modify the vinca alkaloids and taxanes and develop orally bioavailable agents. Antitubulin agents that target the colchicine-binding site in tubulin may provide a better opportunity to be developed for oral use because of their relatively simple structures and physicochemical properties. A potent antitubulin agent, 4-(3,4,5-trimethoxybenzoyl)-2-phenyl-thiazole (SMART-H), binding to the colchicine-binding site, was discovered in our laboratory. However, the bioavailability of SMART-H was low because of its poor solubility. Structural modification of SMART-H led to the development of 2-aryl-4-benzoyl-imidazole analog (ABI-274), with improved bioavailability and potency but still considerable first-pass metabolism. A chlorine derivative (ABI-286), replacing the methyl site of ABI-274, resulted in 1.5-fold higher metabolic stability in vitro and 1.8-fold lower clearance in rats in vivo...

Optimization of Thiazole Analogues of Resveratrol for Induction of NAD(P)H:quinone Reductase 1 (QR1)

Mayhoub, Abdelrahman S.; Marler, Laura; Kondratyuk, Tamara P.; Park, Eun-Jung; Pezzuto, John M.; Cushman, Mark
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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NAD(P)H:quinone reductase 1 (QR1) belongs to a class of enzymes called cytoprotective enzymes. It exhibits its cancer protective activity mainly by inhibiting the formation of intracellular semiquinone radicals, and by generating α-tocopherolhydroquinone, which acts as a free radical scavenger. It is therefore believed that QR1 inducers can act as cancer chemopreventive agents. Resveratrol (1) is a naturally occurring stilbene derivative that requires a concentration of 21 μM to double QR1 activity (CD = 21 μM). The stilbene double bond of resveratrol was replaced with a thiadiazole ring and the phenols were eliminated to provide a more potent and selective derivative 2 (CD = 2.1 μM). Optimizing the substitution pattern of the two phenyl rings and the central heterocyclic linker led to a highly potent and selective QR1 inducer 9o with a CD value of 0.087 μM.

The thiazole derivative CPTH6 impairs autophagy

Ragazzoni, Y; Desideri, M; Gabellini, C; De Luca, T; Carradori, S; Secci, D; Nescatelli, R; Candiloro, A; Condello, M; Meschini, S; Del Bufalo, D; Trisciuoglio, D
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
EN
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We have previously demonstrated that the thiazole derivative 3-methylcyclopentylidene-[4-(4′-chlorophenyl)thiazol-2-yl]hydrazone (CPTH6) induces apoptosis and cell cycle arrest in human leukemia cells. The aim of this study was to evaluate whether CPTH6 is able to affect autophagy. By using several human tumor cell lines with different origins we demonstrated that CPTH6 treatment induced, in a dose-dependent manner, a significant increase in autophagic features, as imaged by electron microscopy, immunoblotting analysis of membrane-bound form of microtubule-associated protein 1 light chain 3 (LC3B-II) levels and by appearance of typical LC3B-II-associated autophagosomal puncta. To gain insights into the molecular mechanisms of elevated markers of autophagy induced by CPTH6 treatment, we silenced the expression of several proteins acting at different steps of autophagy. We found that the effect of CPTH6 on autophagy developed through a noncanonical mechanism that did not require beclin-1-dependent nucleation, but involved Atg-7-mediated elongation of autophagosomal membranes. Strikingly, a combined treatment of CPTH6 with late-stage autophagy inhibitors, such as chloroquine and bafilomycin A1, demonstrates that under basal condition CPTH6 reduces autophagosome turnover through an impairment of their degradation pathway...

CPTH6,an histone acetyltransferase, shows anti-tumor properties

RAGAZZONI, YLENIA
Fonte: La Sapienza Universidade de Roma Publicador: La Sapienza Universidade de Roma
Tipo: Tese de Doutorado
EN
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Recent studies strongly support the histone acetylation as a promising therapeutic target. Although a growing body of evidence demonstrates a direct relationship between histone acetyltransferases (HAT) activity and development or progression of cancer disease, only limited progress has been made in the field of HAT inhibitors. This study identifies the thiazole derivative 3-methyl-cyclopentylidene-[4-(4’-chlorophenyl)thiazol-2yl)hydrazone (CPTH6) as a novel HAT inhibitor in a panel of solid and hematologic tumor cell lines. CPTH6 leads to an inhibition of Gcn5 and pCAF HAT activity. Moreover, it inhibits H3/H4 histones and α-tubulin acetylation of acute myeloid leukemia cell (AML) line U-937. Concentration- and time-dependent inhibition of cell viability, paralleled by accumulation of cells in the G0/G1 phase and depletion from the S/G2M phases, was observed. The role of mitochondrial pathway on CPTH6-induced apoptosis was shown, being a decrease of mitochondrial membrane potential and the release of cytochrome c, from mitochondria to cytosol, induced by CPTH6. Also the involvement of Bcl-2 and Bcl-xL on CPTH6-induced apoptosis was found after over-expression of the two proteins in leukemia cells. Solid tumor cell lines from several origins were shown to be differently sensitive to CPTH6 treatment in terms of cell viability and a correlation between the inhibitory efficacy on H3/H4 histones acetylation and cytotoxicity was found. Differentiating effect on leukemia and neuroblastoma cell lines was also induced by CPTH6. Moreover...

N-Vinyl- and C-Vinylpyrroles from Azafulvenium Methides. Flash Vacuum Pyrolysis Route to 5-Oxo-5H-pyrrolizines and 1-Azabenzo[f]azulenes

Melo, Teresa M. V. D. Pinho e; Soares, Maria I. L.; Gonsalves, António M. d'A. Rocha; Paixão, José A.; Beja, Ana Matos; Silva, Manuela Ramos
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artigo de Revista Científica
ENG
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1-Azafulvenium methides, generated from pyrrolo[1,2-c]thiazole-2,2-dioxides' thermal extrusion of sulfur dioxide, led to the synthesis of functionalized pyrroles. The intramolecular trapping of these transient 8π 1,7-dipoles in pericyclic reactions, namely sigmatropic [1,8]H shifts and 1,7-electrocyclization, allowed the synthesis of N-vinylpyrroles and C-vinylpyrroles which, under flash vacuum pyrolysis conditions, are converted into 5-oxo-5H-pyrrolizines or 4-oxo-1,4-dihydro-1-aza-benzo[f]azulenes, respectively. These heterocycles can also be obtained directly from FVP of pyrrolo[1,2-c]thiazole 2,2-dioxides. The synthesis and X-ray structure of a new 6-oxocyclopenta[b]pyrrole derivative is also reported.

Synthesis of Chiral Pyrrolo[1,2-c]thiazoles via Intramolecular Dipolar Cycloaddition of Münchnones: An Interesting Rearrangement to Pyrrolo[1,2-c]thiazines

Melo, Teresa M. V. D. Pinho e; Soares, Maria I. L.; Gonsalves, António M. d'A. Rocha; Paixão, José A.; Beja, Ana M.; Silva, Manuela Ramos; Veiga, Luiz Alte da; Pessoa, João Costa
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artigo de Revista Científica
ENG
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26.5%
Intramolecular dipolar cycloaddition of bicyclic münchnones, 5H,7H-thiazolo[3,4-c]oxazol-4-ium-1-olates, derived from cyclodehydration of 2-substituted-N-acylthiazolidine-4-carboxylic acids are reported. A range of new pyrrolo[1,2-c]thiazole derivatives (7, 14, 15, 20, 23, and 26) were obtained as single enantiomers from 2-phenylthiazolidines, 2-benzoylthiazolidines, and 2-methylthiazolidine-4-carboxylates. Pyrrolo[1,2-c][1,4]thiazine derivative 27 was also obtained from pyrrolo[1,2-c]thiazole derivative 26. The structures of methyl (2R,4R)-2-(p-methoxybenzoyl)thiazolidine-4-carboxylate (17a), methyl (2R,4R)-2-(p-methoxybenzoyl)-N-(prop-2-ynyloxyacetyl)thiazolidine- 4-carboxylate (18), and 3-oxo-4-phenyl-3,4,6,8-tetrahydro-1H-furo[3‘,4‘:2,3]pyrrolo[1,2-c][1,4]thiazine (27) were determined by X-ray crystallography. Chirooptical studies of the pyrrolo[1,2-c]thiazoles were done by confirming the absolute configuration at the chiral center C-3.; http://dx.doi.org/10.1021/jo010807p

The disruption of a G-alpha subunit sheds new light on the pathogenicity of Stagonospora nodorum on wheat.

Solomon, Peter; Tan, Kar-Chun; Sanches, Pedro; Cooper, Richard M; Oliver, Richard Peter
Fonte: APS Press Publicador: APS Press
Tipo: Artigo de Revista Científica
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Gna1, a gene encoding a Gα subunit, a key component of signal transduction pathways, has been cloned and characterized in the wheat pathogen Stagonospora nodorum. Analysis of Gna1 expression during infection revealed a slight decrease in transcript level

Laser-Induced Fluorescence and Fluorescence Lifetime of Diphenylbenzobis (thiadiazole) in Supersonic Free Jets

Kono, Mitsuhiko
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
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The technique of laser-induced fluorescence (LIF) spectroscopy in supersonic free jets was applied to diphenylbenzobis(thiadiazole) [Angew. Chem., Int. Ed. Engl. 33 (1994) 1977], in the excitation wavelength region of 500-595 nm. The position of the electronic origin was determined to be 589.81 ± 0.02 nm. The LIF excitation spectra indicate that the phenyl groups swing torsionally with large amplitude in the electronically excited state. The fluorescence lifetimes were measured at 11 major vibronic bands to vary between 42.0 and 43.4 ns, with no observable decrease for vibrational energies in the first excited singlet state up to 2605 cm-1. The LIF spectrum and fluorescence lifetime of van der Waals complexes with xenon atoms were also measured. No heavy-atom effect on the fluorescence lifetimes was observed, and therefore the fluorescence quantum yields are expected to be unity even when the excited molecule had a high excess energy up to 2605 cm-1.

Hypersensitivity to cytoskeletal antagonists demonstrates microtubule-microfilament cross-talk in the control of root elongation in Arabidopsis thaliana

Collings, David; Lill, Adrian; Himmelspach, Regina; Wasteneys, Geoffrey
Fonte: Cambridge University Press Publicador: Cambridge University Press
Tipo: Artigo de Revista Científica
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• Elongation of diffusely expanding plant cells is thought to be mainly under the control of cortical microtubules. Drug treatments that disrupt actin microfilaments, however, can reduce elongation and induce radial swelling. To understand how microfila

Preparation of a clay-modified carbon paste electrode based on 2-thiazoline-2-thiol-hexadecylammonium sorption for the sensitive determination of mercury

Dias Filho, Newton L.; Carmo, Devaney R. do; Gessner, Fergus; Rosa, André H.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 1309-1316
ENG
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26.24%
A montmorillonite from Wyoming-USA was used to prepare an organo-clay complex, named 2-thiazoline-2-thiol-hexadecyltrimethylammonium-clay (TZT-HDTA-clay), for the purpose of the selective adsorption of the heavy metals ions and possible use as a chemically modified carbon paste electrode (CMCPE). Adsorption isotherms of Hg 2+, Pb 2+, Cd 2+, Cu 2+, and Zn 2+ from aqueous solutions as a function of the pH were studied at 298 K. Conditions for quantitative retention and elution were established for each metal by batch and column methods. The organo-clay complex was very selective to Hg(II) in aqueous solution in which other metals and ions were also present. The accumulation voltammetry of Hg(II) was studied at a carbon paste electrode chemically modified with this material. The mercury response was evaluated with respect to the pH, electrode composition, preconcentration time, mercury concentration, cleaning solution, possible interferences and other variables. A carbon paste electrode modified by TZT-HDTA-clay showed two peaks: one cathodic peak at about 0.0 V and an anodic peak at 0.25 V, scanning the potential from -0.2 to 0.8 V (0.05 M KNO 3 vs. Ag/AgCl). The anodic peak at 0.25 V presents excellent selectivity for Hg(II) ions in the presence of foreign ions. The detection limit was estimated as 0.1 μg L -1. The precision of determination was satisfactory for the respective concentration level. 2005 © The Japan Society for Analytical Chemistry.