RESUMEN
Meeting the challenge: The zinc/amino alcohol catalyzed enantioselective addition of terminal alkynes to aldehydes is effective with both phenylacetylene and methyl propiolate, leading to chiral secondary propargyl alcohols with very high enantioselectivity (see scheme).
Asunto(s)
Aldehídos/química , Alquinos/química , Amino Alcoholes/química , Propanoles/síntesis química , Zinc/química , Alquinos/síntesis química , Catálisis , Técnicas Químicas Combinatorias , Ciclopropanos/química , Modelos Químicos , Estructura Molecular , EstereoisomerismoRESUMEN
Hypochlorous acid (HOCl)/hypochlorite (OCl-), important reactive oxygen species, play essential roles in many physiological and pathological progresses. Accordingly, we developed a novel dicyanomethylene-4H-pyran (DCM)-based probe DCM-OCl for colorimetric and near-infrared fluorescent turn-on detection of OCl-. The probe exhibited excellent selectivity and sensitivity for OCl- over other bio-related analytes with a detection limit of 80â¯nM. The excellent selectivity of DCM-OCl for OCl- was ascribed to specific oxidative cleavage of the dimethylthiocarbamate (DMTC) recognition unit by OCl-. Moreover, DCM-OCl exhibited an ultrafast turn-on response (<3â¯s) to OCl-, potentially allowing real-time detection of OCl-. Furthermore, DCM-OCl was successfully used to image endogenous/exogenous OCl- in living cells.
Asunto(s)
Benzopiranos/química , Colorantes Fluorescentes/química , Ácido Hipocloroso/análisis , Tiocarbamatos/química , Benzopiranos/síntesis química , Benzopiranos/toxicidad , Colorimetría/métodos , Colorantes Fluorescentes/síntesis química , Colorantes Fluorescentes/toxicidad , Células HeLa , Humanos , Límite de Detección , Tiocarbamatos/síntesis química , Tiocarbamatos/toxicidadRESUMEN
The interaction between acetamiprid and deoxyribonucleic acid (DNA) was used to determine acetamiprid by resonance light scattering (RLS). The RLS signals of DNA were greatly enhanced by acetamiprid in the spectrum region of 300-600 nm. The spectrum peak is around 316.0 nm. The optimum conditions: pH is 1.73; the concentration of DNA is 2.0 microg x mL(-1)bration curve is 0-2. 25 pg * mLU , with the detection2limit of 0. 2 ig * mL '. The acetamiprid in river water sample was determined. The results were satisfactory, and the recovery rates were in the range of 98%-106%. The interaction mechanism of acetamiprid and DNA was discussed: the interactions between acetamiprid and nucleic acid base include electrostatic effect and Tr-r cumulate effect.
Asunto(s)
ADN/química , Piridinas/análisis , Concentración de Iones de Hidrógeno , Luz , Neonicotinoides , Piridinas/química , Dispersión de Radiación , Electricidad EstáticaRESUMEN
Cellulose-tris (3,5-dimethylphenylcarbamate) was prepared after a reported method, and was confirmed by infrared spectroscopy and elemental analysis. Then it was coated onto an amino-propylated mesopore spherical silica gel. The final product was used as the chiral stationary phase of high performance liquid chromatography for the enantioseparation of a novel herbicide ethoxyfen-ethyl. The enantioseparation of ethoxyfen-ethyl on this stationary phase has been achieved for the first time. Mixtures of hexane and isopropanol were used as mobile phases. The effects of isopropanol concentration in the mobile phase on the retention and resolution were investigated. With the decrease of the content of isopropanol in mobile phase, the resolution factors increased. When the isopropanol concentration decreased to one percent, the resolution factor was 3.95. The structural features of the solutes that influence chiral separation are also discussed.