RESUMEN
Objetivos: Realizar una valoración crítica de ciertas prácticas relacionadas con la inmunoterapia alérgeno-específica, sustentadas por la costumbre o por opiniones de expertos. Métodos: Selección aleatoria de documentos de consenso, artículos de opinión, comunicaciones y artículos de revistas, relacionados con la inmunoterapia, y comparación de las afirmaciones expresadas en ellos con los resultados de la literatura científica actual y con experiencias del propio autor. Resultados: Se muestran algunas pruebas de que no siempre las prácticas clínicas más utilizadas o adoptadas por la mayoría son las más adecuadas. Conclusiones: Es necesario seguir realizando esfuerzos para sustentar la inmunoterapia específica y la alergología en hechos objetivos y abandonar las prácticas científicamente inconsistentes
Objectives: To carry out a critical rating about certain practices related to allergen specific immunotherapy, based in habits or in experts opinions. Methods: Randomized selection of consensus documents, opinion articles, communications and magazine articles, related to immunotherapy, and a comparison of the assertions expressed in them with the results of the nowadays scientific literature and with authors own experiences. Results: Some tests are shown to prove that the most used clinical practices or adopted by the majority are not always the most appropriated. Conclusions: Its necessary to keep on making efforts in order to sustain the specific immunotherapy and allergology in objective facts and abandon practices scientifically inconsistent
Asunto(s)
Masculino , Femenino , Recién Nacido , Niño , Adulto , Persona de Mediana Edad , Humanos , Desensibilización Inmunológica/métodos , Alérgenos/administración & dosificación , Alérgenos/uso terapéutico , Inmunoterapia/métodos , Preparaciones Farmacéuticas/efectos adversos , Análisis Multivariante , Posología Homeopática/educación , Posología Homeopática/normas , Asma/inmunología , Asma/terapia , Relación Dosis-Respuesta a Droga , Relación Dosis-Respuesta Inmunológica , Asma/epidemiología , Asma/prevención & controlRESUMEN
The m-chloroperoxybenzoate anion (generated from m-CPBA and bases such as K(2)CO(3) or KOH) is a highly efficient nucleophilic epoxidating reagent for strongly deactivated olefins containing two electron-withdrawing groups at the same carbon, under mild conditions which affect neither other double bonds nor electrophilic oxidizable centers such as sulfoxides.
RESUMEN
No disponible
Asunto(s)
Animales , Humanos , Anisakis , Hipersensibilidad a los Alimentos , Peces/parasitología , Alimentos Congelados/efectos adversos , DietaRESUMEN
[reaction: see text] The dipolarophilic reactivity of enantiopure (Z)-3-p-tolylsulfinylacrylonitriles (1) has been evaluated with diazoalkanes. 3-Cyanopyrazoles are obtained when R = H, but with R = alkyl (Bn, n-Bu, and t-Bu) only one cycloadduct (4 or 5) is formed in high yield under mild conditions, therefore evidencing a complete control of the regioselectivity and the endo/exo and pi-facial selectivities. These reactions are a new straightforward entry to the synthesis of pyrazolines and related structures and reveal the excellent dipolarophilic features of (Z)-sulfinylacrylonitriles.
RESUMEN
Hetero Diels-Alder (HDA) cycloaddition of chiral 1-p-tolylsulfinyl-1,3-pentadiene with benzyl nitrosoformate, under mild conditions, yields 2H-1,2-oxazine 3 with complete regioselectivity and pi-facial diastereoselectivity. Sequential osmylation and protection of the resulting glycol gives the oxazine 5 which is directly transformed into enantiomerically pure 1,4,5-trideoxy-1,4-imino-L-ribitol 8 by reduction under Pd/C.
Asunto(s)
Inhibidores Enzimáticos/síntesis química , Glicósido Hidrolasas/antagonistas & inhibidores , Compuestos Nitrosos/química , Ribitol/análogos & derivados , Ribitol/síntesis química , Ciclización , Inhibidores Enzimáticos/química , Indicadores y Reactivos , Espectroscopía de Resonancia Magnética , Conformación Molecular , EstereoisomerismoRESUMEN
A convergent enantioselective synthesis of (+)-royleanone (1) is described starting from enantiomerically pure (S)-3-hydroxy-2-isopropyl-5-tert-butylsulfinyl-p-benzoquinone, which is readily available from 3-isopropyl-1,2,4-trimethoxybenzene and 1,3,3-trimethyl-2-vinylcyclohexene. The key step is a tandem asymmetric Diels-Alder reaction/pyrolytic sulfoxide elimination process.
Asunto(s)
Abietanos , Diterpenos/síntesis química , Quinonas/química , Estereoisomerismo , Ácidos Sulfínicos/químicaRESUMEN
Lithium dienolate of 3-butenoic methyl ester was reacted with enantiomerically pure N-arylsulfinyl phenylimines (1 and 2) under different conditions. The reactions were completely regioselective-the C-C coupling occurs at the 2-position of dienolate-and highly stereoselective at the iminic carbon. In the presence of different Lewis acids (ZnCl(2), ZnBr(2), and ScTf(3)) mixtures of two alpha-vinyl, beta-arylsulfinylamino esters (epimers at C-alpha) were obtained, being the stereoselectivity depending on the nature of the aryl sulfinyl moiety and the Lewis acid used. Desulfinylation of these mixtures followed by isomerization of the double bond with Na(2)CO(3) allowed the synthesis of the optically pure (E)-alpha-ethylidene-beta-amino ester 10 in quite high overall yield. The addition of the lithium dienolate to sulfinylimines in the absence of the Lewis catalysts yielded mixtures containing important amounts of the optically pure N-arylsulfinyl alpha-ethylidene-beta-amino esters, which became the exclusive product of the reaction when N-2-methoxynaphthylsulfinyl phenylimine 2 was used as starting product.
RESUMEN
In the present paper we report the synthesis, structural characterization, biochemical properties, and antiproliferative activity of two organo-cis-platinum cyclometalated compounds of formula [M(4-OMeC6H4N=C(COC6H5)C6H4)X]2, where M = Pt and X=Cl (4) or OAc (5). The IR and 1H and 13C NMR data of the chloro-bridged compound 4 showed that it has a planar structure. As indicated by IR and 1H and 13C NMR, the acetate-bridged compound 5 has an open-book shape structure. This structure was further confirmed by X-ray diffraction. The comparison of the biochemical properties and antiproliferative activity of these compounds relative to the isostructural palladium compounds [Pd(4-OMeC6H4N=C(COC6H5)C6H4)X]2 [X = AcO (1) and (2) or Cl (3)] indicated that the activity of compounds 4 and 5 is higher than that of the corresponding isostructural compounds 3 and 1-2, respectively, since their ID50 are 2-9-fold lower. It seems that there are not differences in the antiproliferative activity of all these compounds against leukemia HL-60 cells or mammary cancer MDA-MB 468 cells. Compounds 4 and 5 modify also the DNA structure of the oc and ccc forms of plasmid DNA. The acetate-bridged compound 5 showed the highest antiproliferative activity which is even higher than that of cis-DPP. Our data indicate that the Pt(II) compounds are more active than those having Pd(II) as the metal center.