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1.
Phys Rev Lett ; 86(11): 2232-6, 2001 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-11289897

RESUMEN

The Lambda+c lifetime is measured using 9.0 fb(-1) of e+e- annihilation data collected on or just below the Upsilon(4S) resonance with the CLEO II.V detector at CESR. Using an unbinned maximum likelihood fit, the Lambda+c lifetime is measured to be 179.6+/-6.9(stat)+/-4.4(syst) fs. The precision of this colliding beam measurement is comparable to other measurements, which are based on fixed-target experiments, with different systematic uncertainties.

2.
Phys Rev Lett ; 84(26 Pt 1): 5940-4, 2000 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-10991094

RESUMEN

We present a search for direct CP violation in B+/--->J/psiK+/- and B+/--->psi(2S)K+/- decays. In a sample of 9.7x10(6) B&Bmacr; meson pairs collected with the CLEO detector, we have fully reconstructed 534 B+/--->J/psiK+/- and 120 B+/--->psi(2S)K+/- decays with very low background. We have measured the CP-violating charge asymmetry to be [+1.8+/-4.3(stat)+/-0.4(syst)]% for B+/--->J/psiK+/- and [+2.0+/-9. 1(stat)+/-1.0(syst)]% for B+/--->psi(2S)K+/-.

3.
J Med Chem ; 30(8): 1474-82, 1987 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-3612691

RESUMEN

The synthesis of certain heteroarotinoids has been achieved, namely the systems (2E,4E,6E)-3,7-dimethyl-7-(1,2,3,4-tetrahydro-4,4-dimethyl-6 -thiochromanyl)-2,4,6-heptatrienoic acid (1a), ethyl (2E,4E,6E)-3,7-dimethyl-7- (1,2,3,4-teterahydro-4,4-dimethyl-6-thiochromanyl)-2,4,6- heptatrienoate (1b), (2E,4E,6E)-3,7-dimethyl-7-(1,2,3,4-tetrahydro-4,4-dimethyl-6 -chromanyl)-2,4,6-heptatrienoic acid (1c), 2-phthalimidoethyl 3,7-dimethyl-7-(1,2,3,4-tetrahydro-4 4-dimethyl-6-thiochromanyl)-2,4,6-heptatrienoate (1d), methyl (E)-p-[2-(4,4- dimethyl-6-chromanyl)-1-propenyl]benzoate (2a), (E)-p-[2-(4,4-dimethyl-6-chromanyl)-1-propenyl]benzyl alcohol (2b), (E)-p-[2-(4,4-dimethyl-6-chromanyl)-1-propenyl]benzonitrile (2c), (E)-p-[2-(4,4-dimethyl-6-chromanyl)-1-propenyl]benzaldehyde (2d), methyl 4-[2-(2,3-dihydro-3,3-dimethyl-5-benzofuranyl)-1-propenyl] benzoate (3a), and (E)-p-[2-(2,3-dihydro-3,3-dimethyl-5-benzofuranyl)-1- propenyl]benzoic acid (3b). Characterization via elemental, IR, 1H NMR, and 13C NMR analyses was completed for these heterocycles. The biological activity of these heteroarotinoids was assayed by either the suppression of the 12-O-tetradecanoylphorbol 13-acetate (TPA) induced synthesis of ornithine decarboxylase (ODC) in mouse skin or the induction of differentiation of human (HL-60) promyelocytic cells. In the ODC assay, systems 1a-c exhibited strong activity (within 10% of or less than the control) whereas alcohols 2b and 3a showed good activity (within 50% of the control) as compared to either 13-cis-retinoic acid or trans-retinoic acid. Moderate activity was observed with 2a and 2b while 1d and 2c were essentially inactive. With the HL-60 assay, 1a and 1c were approximately 2- and 5-fold less active, respectively, than trans-retinoic acid. In contrast, 2a, 3a, and 3b induced differentiation of only a very small percentage of the cells. Acids 1a and 1c were the most active heteroarotinoids in the two biological assays. Consequently, the presence of the heteroatom does not eradicate the activity of the heteroarotinoids and thus they may have potential as chemotherapeutic agents.


Asunto(s)
Granulocitos/citología , Inhibidores de la Ornitina Descarboxilasa , Retinoides/farmacología , Diferenciación Celular/efectos de los fármacos , Línea Celular , Fenómenos Químicos , Química , Inducción Enzimática/efectos de los fármacos , Humanos , Espectroscopía de Resonancia Magnética , Retinoides/síntesis química , Relación Estructura-Actividad , Tretinoina/farmacología
4.
J Med Chem ; 28(1): 116-24, 1985 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-2578190

RESUMEN

There is reported the first four members of heteroarotinoids, the names of which are ethyl (E)-p-[2-(4,4-dimethylthiochroman-6-yl)propenyl]benzoate (1b), ethyl (E)-p-[2-(4,4-dimethylchroman-6-yl)propenyl]benzoate (1c), ethyl (E)-p-[2-(4,4-dimethyl-1-oxothiochroman-6-yl)propenyl]benzoate (1d), and (E)-p-[2-(4,4-dimethylchroman-6-yl)propenyl]benzoic acid (1e). IR, 1H NMR and 13C NMR data have been recorded for each compound and support the structural assignments. To provide a firm basis for comparison purposes of future analogues, an X-ray analysis was performed on a single crystal of ethyl (E)-p-[2-(4,4-dimethylthiochroman-6-yl)propenyl]benzoate (1b) and a precursor 4,4-dimethylthiochroman-6-yl methyl ketone 1,1-dioxide (18). These data for the heteroarotinoid 1b revealed that the two aryl ring systems were nearly perpendicular in each of the two molecules present in the unit cell (86.37 degrees and 84.17 degrees, respectively). The space group for both molecules was P1 in triclinic systems. Unit cell dimensions (at 15 degrees C) are as follows: for 1b, a = 20.568 (6) A, b = 14.760 (3) A, c = 7.679 (2) A, alpha = 113.33 (2) degrees, beta = 79.45 (2) degrees, gamma = 79.98 (2) degrees, Z = 4; for 18, a = 9.292 (5) A, b = 9.291 (5) A, c = 7.951 (3) A, alpha = 102.16 (3) degrees, beta = 77.49 (3) degrees, gamma = 79.60 (4) degrees, Z = 2. The sulfur-containing ring is in a distorted half-chair in 1b and the methyl carbon C(12) is shown to be trans to H(13) at the C(11)-C(13) bond. The biological activity of these arotinoids was determined in the tracheal organ culture assay and compared with trans-retinoic acid for ability to reverse keratinization in vitamin A deficient hamsters. The ester 1b displayed activity about one-half log unit less than that of the reference while 1c and 1e had activity nearly one log until less than trans-retinoic acid. The sulfoxide was the least active of the heteroretinoids.


Asunto(s)
Benzopiranos/síntesis química , Cromanos/síntesis química , Tráquea/efectos de los fármacos , Deficiencia de Vitamina A/metabolismo , Animales , Cromanos/farmacología , Cricetinae , Queratinas/metabolismo , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Técnicas de Cultivo de Órganos , Tráquea/metabolismo , Difracción de Rayos X
6.
Antimicrob Agents Chemother ; 8(4): 510-2, 1975 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-811160

RESUMEN

The organic salt triethyl-n-hexylammonium triethyl-n-hexylboride (N(2226)B(2226)) has biostatic effects against two gram-positive bacteria, Bacillus subtilis and Micrococcus luteus, and the yeast Candida albicans. Escherichia coli and chicken embryo fibroblasts grown in tissue culture are more refractory to this compound.


Asunto(s)
Antiinfecciosos/farmacología , Bacterias/efectos de los fármacos , Compuestos de Boro/farmacología , Candida albicans/efectos de los fármacos , Compuestos de Amonio Cuaternario/farmacología , Animales , Antibacterianos , Bacillus subtilis/efectos de los fármacos , Embrión de Pollo , Escherichia coli/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Micrococcus/efectos de los fármacos , Factores de Tiempo
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