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1.
PLoS One ; 13(1): e0190710, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29300784

RESUMO

The geological, biological and geochemical features of a particular field of hydrothermal vents, discovered in the Panarea Volcanic Complex during a research survey carried out in 2015, are described for the first time. The site, located at 70-80 m depth off the South-western coast of the islet of Basiluzzo, was named Smoking Land for the presence of a large number of wide and high active chimneys and was characterized in terms of dissolved benthic fluxes, associated macrofauna and megafauna communities and preliminary mineralogy and geochemistry of chimney structures. On the whole field, a total of 39 chimneys, different in size and shape, were closely observed and described; 14 of them showed emission of low temperature hydrothermal fluids of marine origin characterized by acidified chemical conditions. The CTD and benthic chamber measurements highlighted that the Smoking Land is able to form a sea water bottom layer characterized by variable acidity and high DIC and trace elements concentrations; these characteristics weaken moving away from the chimney mouths. The SEM-EDS analysis of the collected solid samples revealed a chimney structure principally composed by amorphous and low crystalline Fe-oxyhydroxides of hydrothermal origins. The ROV explorations revealed a wide coverage of red algae (Peyssonnelia spp.) colonized by the green algae Flabiella petiolata and by suspension feeders, mainly sponges, but also bryozoans, and tubicolous polychaetes. Although novent-exclusive species were identified, the benthic communities found in association to the chimneys included more taxa than those observed in the surrounding no-vent rocky areas. These first findings evidence a submarine dynamic habitat where geological, chemical and biological processes are intimately connected, making the Smoking Land an important site in terms of marine heritage that should be safeguarded and protected.


Assuntos
Fontes Hidrotermais , Oceanos e Mares , Animais , Briozoários , Clorófitas , Conservação dos Recursos Naturais , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Poríferos , Rodófitas , Difração de Raios X
2.
J Med Chem ; 53(20): 7296-315, 2010 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-20873740

RESUMO

Cdc7 serine/threonine kinase is a key regulator of DNA synthesis in eukaryotic organisms. Cdc7 inhibition through siRNA or prototype small molecules causes p53 independent apoptosis in tumor cells while reversibly arresting cell cycle progression in primary fibroblasts. This implies that Cdc7 kinase could be considered a potential target for anticancer therapy. We previously reported that pyrrolopyridinones (e.g., 1) are potent and selective inhibitors of Cdc7 kinase, with good cellular potency and in vitro ADME properties but with suboptimal pharmacokinetic profiles. Here we report on a new chemical class of 5-heteroaryl-3-carboxamido-2-substituted pyrroles (1A) that offers advantages of chemistry diversification and synthetic simplification. This work led to the identification of compound 18, with biochemical data and ADME profile similar to those of compound 1 but characterized by superior efficacy in an in vivo model. Derivative 18 represents a new lead compound worthy of further investigation toward the ultimate goal of identifying a clinical candidate.


Assuntos
Antineoplásicos/síntese química , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Pirimidinas/síntese química , Pirróis/síntese química , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Disponibilidade Biológica , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Camundongos , Camundongos Nus , Transplante de Neoplasias , Pirimidinas/química , Pirimidinas/farmacologia , Pirróis/química , Pirróis/farmacologia , Relação Estrutura-Atividade , Transplante Heterólogo
3.
J Am Chem Soc ; 129(17): 5665-72, 2007 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-17417847

RESUMO

Two novel series of polyfluorinated amino acids (PFAs) were designed and synthesized according to a very short and scalable synthetic sequence. The advantages and limitations of these moieties for screening purposes are presented and discussed. The potential applications of these PFAs were tested with their incorporation into small arginine-containing peptides that represent suitable substrates for the enzyme trypsin. The enzymatic reactions were monitored by 19F NMR spectroscopy, using the 3-FABS (three fluorine atoms for biochemical screening) technique. The high sensitivity achieved with these PFAs permits a reduction in substrate concentration required for 3-FABS. This is relevant in the utilization of 3-FABS in fragment-based screening for identification of small scaffolds that bind weakly to the receptor of interest. The large dispersion of 19F isotropic chemical shifts allows the simultaneous measurement of the efficiency of the different substrates, thus identifying the best substrate for screening purposes. Furthermore, the knowledge of KM and Kcat for the different substrates allows the identification of the structural motifs responsible for the binding affinity to the receptor and those affecting the chemical steps in enzymatic catalysis. This enables the construction of suitable pharmacophores that can be used for designing nonpeptidic inhibitors with high affinity for the enzyme or molecules that mimic the transition state. The novel PFAs can also find useful application in the FAXS (fluorine chemical shift anisotropy and exchange for screening) experiment, a 19F-based competition binding assay for the detection of molecules that inhibit the interaction between two proteins.


Assuntos
Aminoácidos/química , Flúor/química , Anisotropia , Fluorenos/síntese química , Radioisótopos de Flúor/química , Indicadores e Reagentes , Cinética , Espectroscopia de Ressonância Magnética , Peptídeos/síntese química , Tripsina/química
4.
J Med Chem ; 48(8): 3080-4, 2005 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-15828847

RESUMO

Potent and selective Aurora kinase inhibitors were identified from the combinatorial expansion of the 1,4,5,6-tetrahydropyrrolo[3,4-c]pyrazole bi-cycle, a novel and versatile scaffold designed to target the ATP pocket of protein kinases. The most potent compound reported in this study had an IC(50) of 0.027 microM in the enzymatic assay for Aur-A inhibition and IC(50)s between 0.05 microM and 0.5 microM for the inhibition of proliferation of different tumor cell lines.


Assuntos
Antineoplásicos/síntese química , Compostos Bicíclicos Heterocíclicos com Pontes/síntese química , Piperazinas/síntese química , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Pirróis/síntese química , Trifosfato de Adenosina/metabolismo , Antineoplásicos/química , Antineoplásicos/farmacologia , Aurora Quinases , Sítios de Ligação , Compostos Bicíclicos Heterocíclicos com Pontes/química , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Técnicas de Química Combinatória , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Modelos Moleculares , Piperazinas/química , Piperazinas/farmacologia , Ligação Proteica , Proteínas Serina-Treonina Quinases/metabolismo , Pirróis/química , Pirróis/farmacologia , Relação Estrutura-Atividade
5.
J Med Chem ; 47(13): 3367-80, 2004 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-15189033

RESUMO

Abnormal proliferation mediated by disruption of the normal cell cycle mechanisms is a hallmark of virtually all cancer cells. Compounds targeting complexes between cyclin-dependent kinases (CDK) and cyclins, such as CDK2/cyclin A and CDK2/cyclin E, and inhibiting their kinase activity are regarded as promising antitumor agents to complement the existing therapies. From a high-throughput screening effort, we identified a new class of CDK2/cyclin A/E inhibitors. The hit-to-lead expansion of this class is described. X-ray crystallographic data of early compounds in this series, as well as in vitro testing funneled for rapidly achieving in vivo efficacy, led to a nanomolar inhibitor of CDK2/cyclin A (N-(5-cyclopropyl-1H-pyrazol-3-yl)-2-(2-naphthyl)acetamide (41), PNU-292137, IC50 = 37 nM) with in vivo antitumor activity (TGI > 50%) in a mouse xenograft model at a dose devoid of toxic effects.


Assuntos
Acetamidas/síntese química , Antineoplásicos/síntese química , Quinases relacionadas a CDC2 e CDC28/antagonistas & inibidores , Ciclina A/antagonistas & inibidores , Pirazóis/síntese química , Acetamidas/química , Acetamidas/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Sítios de Ligação , Quinases relacionadas a CDC2 e CDC28/química , Linhagem Celular Tumoral , Cristalografia por Raios X , Ciclina A/química , Quinase 2 Dependente de Ciclina , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Modelos Moleculares , Transplante de Neoplasias , Pirazóis/química , Pirazóis/farmacologia , Relação Estrutura-Atividade , Transplante Heterólogo
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