The investigations of bioactive copper(II) complexes with reduced low-molar dextran

Abstract

The optimization of the reaction conditions (pH,T,t) to obtain stable copper(II) ion complexes with dextran derivatives were investigated in this paper. A complete synthesis of stable aqueous complexes can be realized with reduced low-molar polysaccharides, at an average molar mass 5000 g mol–1and pH 7.5–8. Fourier-transform IR spectra of polysaccharide dextran and its compounds with copper(II) ion, recorded at room temperature, were analyzed in order to obtain the information about the structure and the conformation of these polymer compounds. The ESR parameters of the spectra indicate the square-planar coordination of Cu(II) ion with four O atoms. Copper(II) complex formation with dextran and its derivatives were analyzed by physicochemical methods. Synthesized complexes of Cu(II) ion with reduced low-molar dextran in comparison with commercial preparations showed the considerably lower acute toxicity (LD501705).

Structural elucidation of an extracellular polysaccharide produced by the marine fungus Aspergillus versicolor

“…IR spectrum of AWP. Ilić, & Nikolić, 2008;Mitić, Cakić, & Nikolić, 2010;Mitić et al, 2009Mitić et al, , 2011. The bands at 1456 and 1342 cm −1 were the absorption peaks of variable angle vibration of C H bond.…”

Spectroscopic study of copper(II) complexes with carboxymethyl dextran and dextran sulfate

“…The analysis of infrared spectra of synthesized compounds has been accomplished in an empirical manner-on the basis of literature data and internecine comparison of spectrum to referenced dextran compound, carboxymethyl dextran and complex compounds. The infrared spectrum of dextran has been the subject of numerous analyses [6,8,[18][19][20][21][22][23]. By researching the spectrum regions of dextran, the data concerning the content of α-1.6 bond can be obtained (but also concerning other bonds α-1.3, α-1.4) which is very important information regarding linearity, and also regarding the grade of polymer bifurcation, grade of crystallinity, conformation of glucopyranose units (which, as known, has six forms), conformation transition and changes in the chemical structure or some other way changed dextran.…”

“…Very important changes can be observed in the range of 1500-1300 cm -1 by detailed empirical analy- because it provides information about the type of glycoside bond and the conformation of monosaccharide (glucopyranose) unit [6,23]. In this way, for α-1.6 bonds in this area, there are two bands of medium intensity, one at approximately 916 cm -1 and the other at approximately 765 cm -1 .…”

“…Literature brings descriptions of copper complexes with hydrated derivates of low molecular dextran and pullulan [5]. Copper ions along with these ligands form an octahedral complex compound type, the composition of which is changing in correlation with reaction terms of synthesis, thus forming complex compounds CuL 2 · 2H 2 O in neutral, CuL 2 · (H 2 O)(OH), in weakly alkaline area (10-12 pH), and CuL 2 · (OH) 2 in strong alkaline area [5][6][7][8][9][10]. These complex compounds demonstrate the lower level of toxicity and better reabsorption in comparison to the commercial preparations with an inorganic copper salts, and therefore they can be used for the design and optimization of medicines within the treatment of copper insufficiency [11].…”

Analysis of Bioactive Olygosaccharide-Metal Complexes by Modern FTIR Spectroscopy: Copper Complexes

“…5. The results obtained from the structural studies of the investigated complexes were based on other spectroscopic techniques (Nikolic et al, 2005;Mitic et al, 2004;Nikolic et al, 2004;Bartkowiak et al, 1998;Cakic et al, 2008). The changes in number, frequencies, intensity, and width of the FTIR bands in the particular region of ν(O-H) vibrations (3400 cm -1 ), δ(C-H) vibrations (1500-1300 cm -1 ) and ν(C-O) vibrations (1200-1000 cm -1 ) (Fig.…”