RESUMEN
The development of facile methods for conjugating relevant probes, ligands, or delivery agents onto oligonucleotides (ONs) is highly desirable both for fundamental studies in chemical biology and for improving the pharmacology of ONs in medicinal chemistry. Numerous efforts have been focused on the introduction of bioorthogonal groups onto phosphoramidite building blocks, allowing the controlled chemical synthesis of reactive ONs for postsynthetic modifications. Among these building blocks, alkyne, cyclooctynes, trans-cyclooctene, and norbornene have been proved to be compatible with automated solid-phase chemistry. Herein, we present the development of novel 2'-functionalized nucleoside phosphoramidite monomers comprising bioorthogonal methylcyclopropene or sydnone moieties and their introduction for the first time to ON solid-phase synthesis. Traceless ON postsynthetic modifications with reactive complementary probes were successfully achieved through either inverse electron-demand Diels-Alder (iEDDA) reactions or strain-promoted sydnone-alkyne cycloaddition (SPSAC). These results expand the set of bioorthogonal phosphoramidite building blocks to generate ONs for postsynthetic labeling.
Asunto(s)
Alquinos , Sidnonas , OligonucleótidosRESUMEN
Copper-catalyzed and copper-free sydnone-alkyne cycloaddition reactions have emerged as complementary click tools for chemical biology but their use in bioorthogonal labeling is still in its infancy. Herein, combinations of alkynes and coumarin-sydnones were screened for their ability to generate pyrazole products displaying strong fluoroscence enhancement compared to reactants. One sydnone was identified as a particularly suitable new turn-on probe for protein labeling.
RESUMEN
Enantioselective polyclonal antibodies have been produced and characterized to develop a high-throughput screening method for lipase activity fingerprinting, with a view to the enantioselective hydrolysis of azlactones.
Asunto(s)
Anticuerpos/inmunología , Especificidad de Anticuerpos , Evaluación Preclínica de Medicamentos/economía , Evaluación Preclínica de Medicamentos/métodos , Catálisis , Ensayos Analíticos de Alto Rendimiento , Lactonas/química , Lipasa/metabolismo , Estereoisomerismo , Agua/químicaRESUMEN
A library of bisphosphonate-based ligands was prepared using solution-phase parallel synthesis and tested for its uranium-binding properties. With the help of a screening method, based on a chromophoric complex displacement procedure, 23 dipodal and tripodal chelates bearing bisphosphonate chelating functions were found to display very high affinity for the uranyl ion and were selected for evaluation of their in vivo uranyl-removal efficacy. Among them, 11 ligands induced a huge modification of the uranyl biodistribution by deviating the metal from kidney and bones to liver. Among the other ligands, the most potent was the dipodal bisphosphonate 3C which reduced the retention of uranyl and increased its excretion by around 10% of the injected metal.
Asunto(s)
Quelantes/síntesis química , Quelantes/farmacología , Difosfonatos/síntesis química , Difosfonatos/farmacología , Uranio/química , Uranio/farmacocinética , Animales , Sitios de Unión , Huesos/efectos de los fármacos , Huesos/metabolismo , Quelantes/química , Difosfonatos/química , Riñón/efectos de los fármacos , Riñón/metabolismo , Ligandos , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Estructura Molecular , Ratas , Ratas Sprague-Dawley , Bibliotecas de Moléculas Pequeñas/síntesis química , Bibliotecas de Moléculas Pequeñas/química , Bibliotecas de Moléculas Pequeñas/farmacología , Estereoisomerismo , Distribución Tisular/efectos de los fármacos , Uranio/orinaRESUMEN
New tripodal gem-(bis-phosphonates) uranophiles were discovered by a screening method that allowed for the selection of ligands with strong uranyl-binding properties in a convenient microtiter-plate format. The method is based on competitive uranium binding by using Sulfochlorophenol S as chromogenic chelate. This dye compound was found to present high uranyl complexation properties and allowed to highlight ligands presenting association constants for UO(2+)(2) up to 10(18) at pH 7.4 and 10(20) at pH 9. A collection of 40 known ligands including polycarboxylate, hydroxamate, catecholate, hydroxypyridonate and hydroxyquinoline derivatives was tested. Also screened was a combinatorial library prepared from seven amine scaffolds and eight acrylates bearing diverse chelating moieties. Among these 96 tested candidates, a tripod derivative bearing gem-bis-phosphonates moieties was found to present the highest complexation properties over a wide range of pH and was further studied.
Asunto(s)
Naftalenos/química , Compuestos Organometálicos , Sulfonas/química , Uranio/química , Concentración de Iones de Hidrógeno , Ligandos , Estructura Molecular , Compuestos Organometálicos/síntesis química , Compuestos Organometálicos/químicaRESUMEN
We present a new high-throughput screening method for the selection of powerful water-soluble antiradiation compounds. This method, which uses conventional immunoassay techniques, allowed the capacity of a given compound to protect thymidine from irradiation to be evaluated. By applying this assay to an antioxidant library, we showed for the first time that norbadione A, a well-known mushroom pigment, has pronounced atypical antiradiation properties.