The application of a variety of iron complexes with chelating amine ligands as pre-catalysts in the representative cross-coupling of 4-tolylmagnesium bromide with cyclohexyl bromide was investigated. The results from this study indicate the performance of the pre-catalyst is inversely proportional to the strength of the chelate or macrocyclic effect of the amine ligand, as determined by the pro...

The Escherichia coli chaperonin GroEL and its regulator GroES are thought to mediate adenosine triphosphate-dependent protein folding as an asymmetrical complex, with substrate protein bound within the GroEL cylinder. In contrast, a symmetrical complex formed between one GroEL and two GroES oligomers, with substrate protein binding to the outer surface of GroEL, was recently proposed to be the ...

The hydrolysis of the thorium(IV) ion in various concentrations of magnesium, calcium, strontium and barium chloride media was studied by the emf method at 25 °c. The data show that the extent of thorium hydrolysis decreases with increasing concentration and hydration energy of the medium ions. The contribution of the concentration of the medium ions to the total medium effect is higher than th...

The effect of acetylation on the DNA binding properties of the rigidly conserved histone H4 amino-terminal tail has been studied in detail using the technique of thermal denaturation. The quantitative DNA-binding parameters for both the non- and fully acetylated H4 amino terminus have been determined from thermal denaturation data for complexes of the peptides bound to mixed sequence 146-base p...

We designed a hammerhead-type ribozyme system which consists of three RNA fragments and synthesized the component and related ribo-oligonucleotides by the solid-phase phosphoramidite method using o-nitrobenzyl groups for 2'-hydroxyl protection. Improved conditions for photolytic removal of the o-nitrobenzyl groups are described. Imino proton NMR spectra of the ribozyme complex were measured. Th...

Magnesium atoms embedded in superfluid helium nanodroplets have been identified to arrange themselves in a metastable network, referred to as foam. In order to investigate the ionization dynamics of this unique structure with respect to a possible light-induced collapse, the femtosecond dual-pulse spectroscopy technique is applied. Around zero optical delay a strong feature is obtained which re...

The calcium free sarcoplasmic reticulum calcium transport ATPase incorporates in the presence of magnesium ions approx. 8 nmol monovanadate per mg protein, indicating the formation of a complex containing one vanadate residue per enzyme molecule. On ligand-removal or dilution, the saturated enzyme complex displays biphasic decay kinetics, while the unsaturated complex slowly dissociates monopha...

background: hypomagnesaemia is one of the main side effects of cisplatin-based chemotherapy regimens in cancer patients. the aim of the current investigation was to evaluate the effect of oral magnesium oxide (mgo) supplementation on cisplatin-induced hypomagnesemia. methods: this parallel-randomized controlled, open label trial was conducted in a hospital of iran university of medical sciences...