A conceptual method for the preparation of 1,2-diketones is reported. The selective C–C bond cleavage of 1,3-diketones affords the 1,2-diketones in high yields under mild reaction conditions in air by the use of FeCl3 as the catalyst and tert-butyl nitrite (TBN) as the oxidant without the use of solvent. The possible reaction mechanism is discussed. This protocol provides an expeditious route to the
Protein particles for therapeutic and diagnostic use
申请人:——
公开号:US20020142046A1
公开(公告)日:2002-10-03
Albumin particles in the nanometer and micrometer size range in an aqueous suspension are rendered stable against resolubilization without the aid of a cross-linking agent and witout denaturation, by the incorporation of a stabilizing agent in the particle composition. Stabilizing agents disclosed include reducing agents, oxdizing agents, hydrogen-accepting molecules, high molecular weight polymers, and sulfur-containing ring compounds. Also disclosed are fibrinogen-coated particles, cross-linked or non-cross-linked, and their use as co-aggregants with platelets and with themselves for purposes of shortening bleeding time and enhancing the effect of thrombin.
The maize yellow stripe1 gene encodes a transmembrane protein which mediates the uptake of chelated iron from soil. The gene is shown here to be upregulated, and protein production increased, under conditions of low iron bioavailability. The protein is also shown to be able to transport other metals as well, such as copper. The present invention also provides a family of Arabidopsis genes and gene products related to ys1 termed here as ys11-8. The invention provides the genes and their gene products as well as methods to create and use transgenic plants for the increased uptake of iron in nutritional crops as well as for the bioremediation of soil.
Steady state and laser photolysis studies of keto-enol tautomerizations in 2-alkyl-1,3-diketones having five-membered rings in acetonitrile: Temporal UV-A sunscreen
作者:Yurie Suwa、Minoru Yamaji
DOI:10.1016/j.jphotochem.2015.10.010
日期:2016.2
Keto-enol tautomerization in 2-alkyl-1,3-diketons having five-membered rings was studied using steady state and laser flash photolysis techniques in solution. The alkyl keto-diketones undergo photoinduced tautomerization mainly in the triplet state to the enol in acetonitrile. The alkyl enol-diketones, thus formed, undergo thermal tautomerization to the original keto forms in a few days. The alkyl enol-diketones show fast internal conversion from the excited singlet state to the ground state without yielding the corresponding isomeric forms (rotamer). Based on the computation for state energies of the keto, enol and isomer forms, a schematic energy diagram for the tautomerization was drawn. (C) 2015 Elsevier B.V. All rights reserved.