Low Molecular Weight Complexes

Kwong KF Ng Kee, Huang PM (1979b) Nature of hydrolytic precipitation products of aluminum as influenced by low molecular weight complexing organic... 

The dependence of (20 MHz and 25° C) on is graphically represented in Pig. 3 for monoaqua Gd(III) complexes with different values of the rotational correlation times. The limiting effect of the residence lifetime is small for low molecular weight complexes (xf> = 50 100 ps) and detectable only when On the other hand, for slowly tumbling... 

Nickel that is absorbed is excreted primarily in the urine. In the urine, nickel is primarily associated with low molecular weight complexes that have free amino acids as indicated by the ninhydrin reaction (Sunderman and Oskarsson 1991). In humans nickel is also eliminated in hair, skin, milk, and sweat. 

Figure 309 Periodate oxidation of HRP creates aldehyde groups on the carbohydrate chains of the enzyme. Reaction with a Fab fragment then may be done using reductive amination to produce a low-molecular-weight complex.

Some efforts have been made to interpret the spectroscopic and magnetic properties of cobalt enzymes in terms of coordination geometry and chemical identity of ligands. The basis of these attempts is a comparison with the corresponding properties of low-molecular weight complexes of known structure. A brief summary of relevant data on some models is given in the following section. 

Copper complexes are the principal antiinflammatory agents under investigation at the moment39,40, although elsewhere in this review one or two other chelates are also discussed. The mechanisms by which copper complexes exert antiinflammatory action are no doubt numerous. However, it has been shown that some low molecular weight complexes dismute superoxide (O )41,42. ... 

Aluminum can form complexes with many molecules in the body (organic acids, amino acids, nucleotides, phosphates, carbohydrates, macromolecules). Free aluminum ions (e.g., A1(H20)63+) occur in very low concentrations. The toxicokinetics of aluminum can vary, depending on the nature of these complexes. For example, aluminum bound in a low-molecular-weight complex could be filtered at the renal glomeruli and excreted, while aluminum in a high-molecular-weight complex would not. 

May P. M., Linder P. W., and Williams D. R. (1977) Computer simulation of metal-ion equilibria in biofluids models for the low-molecular-weight complex distribution of calciu-m(II), magnesium(II), manganese(II), iron(III), copper(II), zinc(II), and lead(II) ions in human blood plasma. J. Chem. Soc. Dalton Trans. 588—595. 

Kwong, K. F. Ng Kee, and Huang, P. M. (1979a). The relative influence of low-molecular-weight complexing organic acids on the hydrolysis and precipitation products of aluminum. Soil Sci. 128, 337-342. 

Biomimetic oxidations refer to oxidations carried out by relatively low molecular weight complexes which mimic biological systems in their catalytic efficiency. The subject is covered in recent tomes edited by Meunier [208] and van Eldik and Reedijk [209]. 

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