The mutant hemoglobin S (HbS) previously was reported to undergo accelerated autooxidation during incubation in vitro. However, subsequent observations have raised the possibility that this might be explained by adventitious association of molecular iron with HbS, rather than reflecting an inherent property of HbS. Using purified HbA and HbS obtained from genotypic HbAS donors, we found that th...

[figure: see text] Chelation and aggregation in phenyllithium reagents with potential 5-, 6-, and 7-ring chelating ether and amine ortho substituents have been examined utilizing variable-temperature 6Li and 13C NMR spectroscopy, 6Li and 15N isotope labeling, and the effects of solvent additives. Both ether and amine form strong 5-ring chelates; 6-ring ether chelates compete well with THF, but ...

The strawberry is a low-growing, herbaceous perennial plant, sensitive to iron deficiency. deficiency represents nutritional disorder, leading decreased content of photosynthetic pigments, which determines the yellow color characteristic chlorotic leaves. Therefore, in calcareous soils, use synthetic chelate often mandatory cultivation. employment novel microorganism-based formulations as alter...

The synthesis and characterisation of cobalt(III) chelates of 3-nitroformazans have been described. These chelates have been characterized as tris chelates on the basis of elemental analysis, IR and H NMR studies. These studies reveal that the coordination of the cobalt(III) to the ligands occurs through the nitrogen atoms 1 and 5 of the formazyl group and that the NO2 group of the ligand does ...

The coordinating atoms in polydentate chelates are primarily heteroatoms. We present the first examples of pentadentate chelates with all binding atoms of the chelating agent being carbon atoms, denoted as CCCCC chelates. Having up to five metal-carbon bonds in the equatorial plane has not been previously observed in transition metal chemistry. Density functional theory calculations showed that...

The kinetics of iron accumulation by iron-starved Paracoccus denitrificans during the first 2 min of exposure to 55Fe-labeled ferric siderophore chelates is described. Iron is acquired from the ferric chelate of the natural siderophore L-parabactin in a process exhibiting biphastic kinetics by Lineweaver-Burk analysis. The kinetic data for 1 microM less than [Fe L-parabactin] less than 10 micro...

Polyaminocarboxylate-based luminescent lanthanide complexes have unusual emission properties, including millisecond excited-state lifetimes and sharply spiked spectra compared to common organic fluorophores. There are three distinct sections in the structure of the luminescent lanthanide chelates: a polyaminocarboxylate backbone to bind the lanthanide ions tightly, an antenna molecule to sensit...

Iron chlorosis is common in vineyards grown on calcareous soils, and consists of a chlorophyll deficiency caused by disorder iron nutrition. It manifested interveinal yellowing the youngest leaves decreased growth production. Most Spain are planted so frequent, even tolerant rootstocks. In case Spain, Tempranillo accounts for 20.8% total Spanish wine area, with this red variety being most plant...

The potentiality of lanthanide chelates as photoluminescent markers and cleaving agents of nucleic acids is discussed, the main emphasis being on the chelates derived from aromatic nitrogen bases.