Enantioselective adsorption of dipeptides on chiral stationary phases with grafted macrocyclic antibiotics using glycylaspartic acid as an example

The chromatographic behavior and adsorption of enantiomers of glycylaspartic acid on the Nautilus-E chiral stationary phase with grafted eremomycin antibiotic were studied. Acetate buf er mixtures with variable pH prepared in a water—methanol mixed solvent (volume ratio 60 : 40) were used as acetate buf ers. The retention of Gly—Asp was found to be enantioselective and depending on the ratio of various ionic forms of dipeptide in the mobile phase. The ratio is determined by the pH. A model of adsorption equilibrium assuming independent binding of diverse ionic forms with the stationary phase, which is characteristic of energy uniformity, was proposed. This model is well consistent with the experimental data. Features of application of the equilibrium dispersion and transport dispersion dynamic elution models for the determination of the adsorption isotherms by the inverse method are discussed.

     

Ab initio molecular force fields fitted in Cartesian coordinates to experimental frequencies of isotopic species using symmetry constraints: application to indole and pyrrole molecules

Structural Chemistry - We present the new computational procedure for the fitting ab initio molecular force fields represented in Cartesian coordinates to the experimental frequencies with...     

Effect of Plasma Surface Modification of Mixed Leaf Litter on the Mechanism of Oil Film Removal from Water Bodies

Russian Journal of General Chemistry - The effect of the plasma modification of mixed leaf litter on the mechanism of oil removal from water surface was studied. It was found that that the sorption...     

Synthesis of Lutein and Astaxanthin Esters and Their In Silico Activity

Russian Journal of General Chemistry - Esters of individual natural carotenoids lutein and astaxanthin with benzoic, 4-methylbenzoic, nicotinic, and mandelic acids have been synthesized. The...     

3-Amino-4-[5-(chloromethyl)-1,2,4-oxadiazol-3-yl]furazan –a multifunctional synthon for the synthesis of 1,2,5-oxadiazole derivatives

Chemistry of Heterocyclic Compounds - The chemical properties of 3-amino-4-[5-(chloromethyl)-1,2,4-oxadiazol-3-yl]furazan were scrutinized: acylation of the amino group and its oxidation to azo and...     

Effect of cryohypobiosis on conservation of human blood leukocytes

Morphological and functional indicators were investigated of donor leukocyte concentrates mixed at a ratio of 1 to 1 with three versions of cold-protective and kept at an undercooling temperature (-10 degree C) for 24 hours, and with a cryoprotector of optimal composition for 12 days,. An optimal version of a non-freezing cold-protective solution was found. It was determined that 76+/-4 % of the neutrophils retain there ability of phagocytosis among the viable cells (81+/-5 %) after a 12 day hypobiosis. Thus the results testify to a high morphofunctional safety of human blood leukocytes which experienced cold-hypobiosis (-10 degree C) in an original non-freezing solution not requiring washing after re-warming.