نتایج جستجو برای: metalloporphyrins
تعداد نتایج: 554 فیلتر نتایج به سال:
The role of hemin in the maintenance of protein synthesis in reticulocyte lysates was examined by comparing the effects of various porphyrins and metalloporphyrins on the protein kinase activity of the hemin-controlled repressor and on protein synthesis. The porphyrin requirements for maintenance of protein synthesis were relatively specific. Iron and cobalt metalloporphyrins sustained protein ...
This is another of an increasing number of human gross anatomy books being published in abbreviated form. Throughout the book each left-hand page contains quite accurate written descriptions of structures that are illustrated as line drawings on the opposite right-hand page. Even though the text is written in a telegraphic style and the drawings are small, the book still contains 443 pages. It ...
New metalloporphyrins bearing one or two aryl-aza-crown ether moieties at meso-positions have been synthesized using a palladium catalyzed amination reaction and fully characterized by spectral techniques. X-Ray structural data have been presented for the zinc and copper complexes of mono-substituted aza-crown ether appended metalloporphyrins. UV-Vis and (1)H NMR spectroscopic studies showed th...
On account of their structural similarity to cofactors found in many metallo-enzymes, metalloporphyrins are obvious potential building blocks for catalytically active, metal-organic framework (MOF) materials. While numerous porphyrin-based MOFs have already been described, versions featuring highly accessible active sites and permanent microporosity are remarkably scarce. Indeed, of the more th...
Carbene transfer reactions are very important transformations in organic synthesis, allowing the generation of structurally challenging products by catalysed cyclopropanation, cyclopropenation, carbene C-H, N-H, O-H, S-H, and Si-H insertion, and olefination of carbonyl compounds. In particular, chiral and achiral metalloporphyrins have been successfully explored as biomimetic catalysts for thes...
1. The preparation and characterization of manganese, iron, cobalt, nickel, copper and zinc metalloporphyrins is described. Ferrihaem was also esterified with pyrid-4-ylpropanol and the derivative characterized as the diester. 2. Complexes of these various porphyrins, as well as protoporphyrin IX, with apomyoglobin were formed and the resulting artificial myoglobins characterized. 3. Very littl...
The redox properties of metalloporphyrins have been studied extensively, and particular attention has been paid to the changes in oxidation states of the metaL t-3 In general, the most stable metalloporphyrins are those in which the metal is in the + 2 oxidation state. However, most of the transition metalloporphyrins show a variety of oxidation states. Thus Co(ll) porphyrins can, like the corr...
A new class of sterically hindered dendrimer-metalloporphyrins was synthesized for use as shape-selective oxidation catalysts. A series of oxidatively robust poly(phenylesters) dendrimers were prepared through a convergent synthesis. Monodendrons were appended to the meta-positions of the 5,10,15,20-tetrakis(3′,5′-hydroxyphenyl)porphinatomanganese(III) chloride to obtain a sterically protected ...
Paramagnetic metalloporphyrins were examined for their in vivo bio-distribution and their ability to enhance nuclear magnetic resonance imaging of human tumor xenografts in nude mice. The metalloporphyrins tested were: manganese tetrasodium-meso-tetra(4-sulfonatophenyl)-porphine (MnTPPS); manganese meso-tetra-4-pyridylporphine; and gadolinium meso-tetra-4-pyridylporphine. All exhibited high mol...
Several studies in the last two decades have demonstrated that metalloporphyrins coated quartz microbalances can be fruitfully used in many diverse applications, spanning from medical diagnosis to environmental control. This large versatility is due to the combination of the flexibility of metalloporphyrins molecular design with the independence of the quartz microbalance signal from the interac...
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