Achillea tenuifolia Lam. (Asteraceae) afforded a dichloromethane fraction from which three known compounds β-sitosterol (compound1), 5-hydroxy, 4',6,7– trimethoxy flavone (salvigenin compound 2), and methyl-gallate (compound 3) were isolated for the first time. The structure of isolated compounds was elucidated by different spectroscopic methods. Applying the molar-ratio method, the complexat...

The batch adsorption of Mn (II), Zn (II) and Cu (II) ions from aqueous solution using frond and leaves of dump palm was investigated. The influence of sorption time, initial metal ion concentration and adsorbent dosage were evaluated. The results showed that these parts of dump palm have relatively high adsorption capacity for these heavy metals ions. The percentage removed was (76%), (64%), (6...

This study investigated the effect of metal ions on the oxidation of sterols and their kinetics in oil-in-water emulsions. Sterol substrates were added with different metal ions (Cu(2+), Fe(2+), Mn(2+), Zn(2+), Na(+), and Mg(2+)) of five concentrations and investigated after 2 h of heating at 90 °C. The substrates added with Fe(2+) and Cu(2+) were heated continuously to evaluate the kinetics of...

Glycosyltransferases are sugar-processing enzymes that require a specific metal ion cofactor for catalysis. In the presence of other ions the catalysis is often impaired. Here, for the first time, the enzymatic catalysis in the presence of various metal ions was modeled for a glycosyltransferase using a large enzymatic model. The catalytic mechanism of α-1,2-mannosyltransferase Kre2p/Mnt1p in t...

The effect of cell density (number of cells per unit area of a monolayer culture) on the in vitro cytotoxicity of metal ions which are known to be released from dental materials was investigated. The effects of cell density (1) may explain previous discrepancies in in vitro tests, (2) may be important in wound healing where cell density changes over time, and (3) may help clarify the mechanisms...

Based on theoretical molecular modeling performed in this study, both structural and catalytic zinc ions, Zn and Zn, respectively, were shown to influence the structural integrity of the substrate binding pocket of human alcohol dehydrogenase b2b2 in the middle and outer regions. The replacement of both Zn s and Zn with different metal ions restricts the access of bulky substrates to the bottom...

— The influence of the Zn and Cd ion contents upon the natural spin resonance in Ni-Zn and Ni-Cd ferrites has been investigated. Previous experiments by other authors have shown that substituting Zn ions for Ni ions leads to a change of the total effective anisotropy field and consequently of the natural spin resonance frequency fi. ft measurements have been carried out by using a coaxial line ...

The asymmetric unit of the title compound, [Zn(C(3)H(7)NO)(2)(H(2)O)(4)][Zn(C(13)H(10)N(2)O(5))Cl](2), is composed of a single anion and half a cation. The Zn(II) atom in the monoanion has a distorted triganol-pyramidal geometry, being coordinated by three O atoms and one N atom from one 2-{3-[2-(carboxyl-ato-meth-oxy)phen-yl]pyrazol-1-yl}acetate ligand and one Cl atom. In the dication, the Zn(...

The interactions of Zn(ll) ions with the blocked hexapeptide models -TESHHK-, -TASHHK- and -TEAHHK- of the -ESHH- motif of the C-terminal of historic H2A were studied by using potentiometric and IH-NMR techniques. The first step of these studies was to compare the pKa values of the two His residues inside each hexapeptide calculated by potentiometric or H-NMR titrations. Hereafter, the potentio...

We applied the whole-cell patch-clamp technique to study the influence of zinc ions (Zn(2+)) and extracellular protons at acidic pH (pH(o)) on voltage-gated potassium currents in cultured rat hippocampal neurons. The first goal of the study was to estimate whether Kv1.3 currents significantly contributed to voltage-gated potassium currents in examined cells. Then, the influence of both ions on ...