RESUMEN
A short, convergent synthesis of the mushroom pigment norbadione A is described. The construction of an appropriately substituted naphtholactone intermediate involved a regioselective Diels-Alder reaction between a bis(triisopropylsilyloxy)diene and 2,6-dichlorobenzo-1,4-quinone. A double Suzuki-Miyaura cross-coupling between a diboronate and two identical enol triflates was another key feature of the synthesis.
Asunto(s)
4-Butirolactona/análogos & derivados , Fenilacetatos/síntesis química , 4-Butirolactona/síntesis química , 4-Butirolactona/química , Cristalografía por Rayos X , Modelos Moleculares , Estructura Molecular , Fenilacetatos/química , EstereoisomerismoRESUMEN
A recently reported high-throughput screening strategy has been applied to the rapid selection of new water-soluble antioxidants that display strong protective activities. Based on a competitive immunoassay, a triple-screening procedure was used to evaluate the ability of different compounds to protect thymidine under different oxidative stresses. The pro-oxidant effect of norbadione A in the presence of iron was observed, while some pulvinic acid derivatives proved strongly protective during gamma radiolysis, UV irradiation, and Fenton-like oxidation.
Asunto(s)
Antioxidantes/química , Antioxidantes/farmacología , Flavonoides/química , Oxidantes/química , Fenoles/química , Timidina/química , 4-Butirolactona/análogos & derivados , 4-Butirolactona/química , Ácidos Carboxílicos/química , Cromatografía Líquida de Alta Presión , Estudios de Evaluación como Asunto , Flavonoides/fisiología , Inmunoensayo , Lactonas/química , Oxidantes/farmacología , Estrés Oxidativo , Fenilacetatos/química , Polifenoles , Quercetina/química , Especies Reactivas de OxígenoRESUMEN
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.
Asunto(s)
4-Butirolactona/análogos & derivados , 4-Butirolactona/farmacología , Evaluación Preclínica de Medicamentos/métodos , Inmunoensayo/métodos , Fenilacetatos/farmacología , Protectores contra Radiación/farmacología , Timidina/química , 4-Butirolactona/química , Agaricales/química , Antioxidantes/química , Antioxidantes/clasificación , Antioxidantes/farmacología , Factores Biológicos/química , Factores Biológicos/farmacología , ADN/efectos de la radiación , Relación Dosis-Respuesta a Droga , Estudios de Evaluación como Asunto , Fenilacetatos/química , Extractos Vegetales/química , Protectores contra Radiación/química , Solubilidad , Timidina/efectos de la radiación , Factores de TiempoRESUMEN
The alkylation of the lithium enolate of enantiopure alpha-cyclohexylsulfinyl thioacetamide 1 with allyl bromides 5 possessing an electron-withdrawing group at the vinylic position does not occur at the sulfur center - as expected in the sulfur series - but at the carbon center through conjugate addition followed by bromide elimination. The modest to excellent 1,2-asymmetric induction achieved by the alkylsulfinyl group (dr up to 100:0) is explained by an electronic model.
