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Jason E. Imbriglio Daniel DiRocco Subharekha Raghavan Richard G. Ball Nancy Tsou Ralph T. Mosley James R. Tata Steven L. Colletti 《Tetrahedron letters》2008,49(33):4897-4900
The optimization of a palladium-catalyzed amidation reaction providing a new class of amino acid-tetrahydroanthranilic acid derivatives has been achieved. The scope of the reaction and preliminary conformational analysis of the resulting series of molecules is discussed. 相似文献
104.
The present article describes the synthesis, characterization, and antidiabetic activity of 6‐methoxyimidazo[1,2‐b]pyridazine derivatives 7a‐l . The synthetic sequence for the preparation of these derivatives involves the following prominent reactions: (a) Step 1: involves the high‐pressure amination reaction; (b) Step 2: involves the Zinc oxide nanoparticle‐catalyzed cyclization reaction; (c) Step 3: involves the methoxylation; (d) Step 4: involves the bromination reaction; (e) Step 5: involves the Suzuki coupling reaction; (f) Step 6: involves the reduction of the –NO2 group; (g) Step 7: involves Boc protection of the 1o amino group (h) Step 8: involves diazotization of the amine group and finally the last of the synthesis (i) Step 9: involves the saponification of the ethyl ester group. Furthermore, the structures of the newly synthesized 6‐methoxyimidazo[1,2‐b]pyridazine derivatives 7a–l were determined using 1H NMR, 13C NMR, and Mass and IR spectroscopic analyses. These derivatives were evaluated for their antidiabetic property and the results revealed that most of the compounds exhibited significant potency. It is worth mentioning that compounds 7b (69.87%), 7f (69.0%), 7h (68.79%), and 7l (68.61%) with substitution R = para‐NH2, para‐COOH, meta‐NH2, and meta‐COOH, respectively, showed significant (good) hypoglycemic activity when compared to the standard drug insulin (50 mg/kg b.w) in reducing the blood glucose level. 相似文献
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Jenny?AlongiEmail author Jennifer?Tata Alberto?Frache 《Cellulose (London, England)》2011,18(1):179-190
Suspensions of nanoparticles (namely, hydrotalcite and nanometric silica) have been employed during the finishing of cotton
in order to improve its thermal stability and/or flame retardancy. The immersion approach has also been coupled to a surface
pre-treatment of the textile by cold oxygen plasma in order to load a higher amount of nanoparticles onto fibres. The time
of immersion and the resulting distribution of the nanoparticles onto the fibres, evaluated by scanning electron microscopy
in combination with elemental analysis, have been thoroughly investigated. The present study has shown that the above parameters
are functions of nanoparticle type. Pre-treatment by cold plasma has been found to be more effective than the immersion only.
As far as the thermal stability and the combustion behaviour of treated cotton are concerned, the nanoparticles turned out
to be able to delay the degradation in air, modifying mechanism and kinetics, and at the same time enhancing the flame retardancy
of cotton by increasing the time to ignition and decreasing the heat release rate peak during the combustion. The joint effect
of the two nanoparticles has also been evaluated and found more efficient than the effect of single species. 相似文献
107.
The silica–silver core–shell particles were synthesized by simple one pot chemical method and were employed on the cotton fabric as an antibacterial agent. Extremely small (1–2 nm) silver nanoparticles were attached on silica core particles of average 270 nm size. The optimum density of the nano silver particles was found which was sufficient to show good antibacterial activity as well as the suppression in their surface plasmon resonance responsible for the colour of the core–shell particle for antibacterial textile application. The change in the density and size of the particles in the shell were monitored and confirmed by direct evidence of their transmission electron micrographs and by studying surface plasmon resonance characteristics. The colony counting method of antibacterial activity testing showed excellent results and even the least silver containing core–shell particles showed 100% activity against bacterial concentration of 104 colony counting units (cfu). The bonding between core–shell particles and cotton fabric was examined by X-ray photoelectron spectroscopy. The antibacterial activity test confirmed the firm attachment of core–shell particles to the cotton fabric as a result 10 times washed sample was as good antibacterial as that of unwashed sample. The bacterial growth was inhibited on and beneath the coated fabric, at the same time no zone of inhibition which occurs due to the migration of silver ions into the medium was observed indicating immobilization of silver nanoparticles on silica and core–shell particles on fabric by strong bonding. 相似文献