Effect of binary and ternary polyvinylpyrrolidone and/or hydroxypropyl-beta-cyclodextrin complexes on the photochemical and photosensitizing properties of Naproxen

The effect of the polyvinylpyrrolidone and/or hydroxypropyl-beta-cyclodextrin on the photo-lability of aqueous solutions of the anti-inflammatory drug Naproxen was studied. Kinetic studies revealed that the presence of all of these additives reduced drug photodegradation. In all cases, the presence of the different additives elicited a change in the photomixture composition, being the alcoholic derivative the major photoproduct formed. Nevertheless, the change in the efficiency of the process and the amount of the photoproducts formed in the different systems were not related with the biodamage produced by the drug. In this sense, the presence of free Naproxen clearly sensitized the photoperoxidation of linoleic acid. The photosensitizing effect decreased as the PVP concentration increased. Different protection provides the binary (Naproxen:HP-beta-CD) and ternary (Naproxen:HP-beta-CD:PVP) complexes. The binary complex formation had not effect on the prevention of photooxidation of linoleic acid sensitized by the drug, whereas the ternary complex formation suppresses the drug effect. The different behaviour observed with beta-CD and HP-beta-CD and the structural differences of both cyclodextrins seem to indicate that in the case of the HP-beta-CD the linoleic binds with the CD and takes contact with the drug. These results confirm that in these systems the prevention of biodamage would be due to a decrease in the contact between the short-lived species generated during Naproxen photodegradation and biological structures, rather than due to the nature or amount of the photoproducts. In addition, the ability of the complex to interact with the biological structure depends on the structure of both interacting species.     

Investigation and physicochemical characterization of vinpocetine-sulfobutyl ether beta-cyclodextrin binary and ternary complexes

The purpose of this study was to investigate the interactions between vinpocetine (VP), sulfobutyl ether beta-cyclodextrin (SBEbetaCD) and the water-soluble polymers polyvinylpyrrolidone (PVP) and hydroxypropyl methylcellulose (HPMC). The water-soluble polymers were shown to improve the complexation efficiency of SBEbetaCD, and thus less SBEbetaCD was needed to prepare solid VP-SBEbetaCD complexes in the presence of the polymers. The interactions between VP and SBEbetaCD, with or without PVP or HPMC, were thoroughly investigated in aqueous solutions using the phase-solubility method as well as in the solid state. The amount of VP solubilized in water or aqueous polymer solution increased linearly with increasing SBEbetaCD concentration, demonstrating A(L)-type plots. We estimated the apparent stability constant (K(c)) at room temperature of VP-SBEbetaCD binary complex to be 340 M(-1) and this value increased to 490 M(-1) or 390 M(-1), respectively, with the addition of PVP and HPMC, assuming a 1 : 1 VP-SBEbetaCD molar ratio. Improvement in the K(c) values for ternary complexes clearly confirmed the benefit of the addition of water-soluble polymers to promote higher complexation efficiency. Solid VP-SBEbetaCD binary and ternary systems were prepared by physical mixing, kneading, coevaporation, and lyophilization methods and fully characterized by scanning electron microscopy, differential scanning calorimetry, and X-ray diffractometry. The results obtained suggest that coevaporation and lyophilization methods yield a higher degree of amorphous entities and indicated formation of VP-SBEbetaCD binary and ternary complexes.     

Synthesis and photosensitizing properties of fluoroalkoxyl phthalocyanine metal complexes

Nine fluoroalkoxyl phthalocyanine metal complexes (Zn, AlCl, Mg, Co, Cu, FeCl) were synthesized from 4-(polyfluoroalkoxyl) phthalic anhydride. The fat-soluble phthalocyanines were characterized by elemental analysis, IR, ¹H NMR and fast-atom-bombardment mass spectroscopy. Zinc and aluminum chloride complexes show higher photooxidation ability in solution containing 20% perfluorocarbons than in hydrocarbon solvents.     

Equilibrium studies of the binary and ternary complexes involving tetracycline and amino acid or DNA constituents

The acid-base equilibria of tetracycline and its copper(II) complex formation equilibria are investigated in dioxane-water mixtures. The ternary complexes of copper(II) with tetracycline as primary ligand and amino acid or DNA constituent as secondary ligand are studied in 50% dioxane-water solution. The formation constants of the ternary and binary complexes with amino acids or DNA constituents are determined. The concentration distribution of the various complex species are evaluated. Probable mode of chelation with tetracycline and DNA constituents is discussed.     

Coordination properties of 6-aminopenicillanic acid: binary and ternary complexes involving biorelevant ligands

Formation equilibria of copper(II) complexes of 6-aminopenicillanic acid (APA) and the ternary complexes Cu(APA)B (B?=?glycine, alanine, valine, isoleucine, phenylalanine, proline, hydroxyproline, serine, threonine, ornithine, histidine, methionine, glycylglycine and inosine) were investigated at 25°C and 0.1?M ionic strength. The speciation of the complexes was resolved. Values of Δlog?K, log?X and log?β_stat indicate a large enhancement of the stability of the mixed ligand complexes. The effects of temperature and organic solvent on the dissociation constant of APA and the formation constant of Cu(APA) were studied and thermodynamic parameters were calculated. The solid complex of Cu(APA)Cl·2H₂O was separated and identified by elemental analysis and infrared spectroscopy. In the complex APA is coordinated to copper(II) through the amino group and β-lactam carbonyl oxygen. Absorption spectra of the binary complexes of copper(II) and APA were also investigated.     

Potentiometric studies of binary and ternary complexes of amoxycillin

The formation equilibria for the binary complexes of copper(II), nickel(II), cobalt(II) and zinc(II) with amoxycillin (Amx) and for the ternary complexes M(Arm)(Amx), where Arm refers to aromatic amines, namely 2,2′-dipyridyl or 1,10-phenanthroline, were investigated by a potentiometric technique. The protonation constants of amoxycillin and conditional stability constants of the formed complexes were determined at 25° (=0.1M NaNO₃). Probable mode of chelation with amoxycillin is discussed.     

L-苏氨酸二元和三元配合物的PH电位法研究

本文报道了L-苏氨酸同Cu(II),Zn(II),Fe(II),Mn(II),Ca(II),Mg(II),Ni(II),Cd(II)的二元及三元配合物的pH电位法研究.电位滴定数据是使用MINIQUAD和ESTA计算机程序处理的.在每个体系中确定了最佳配合物粒子模型,并测定了在生理条件下(温度为37±0.1℃离子强度为150mmol.dm^-3NaCl)的稳定常数.结果表明在铜配合物中Cu,Thr.His混配配合物是与Cu(His)~2^-同样重要的配合物,因此需要重新计算在血浆中铜在这些配合物中的分布.虽然苏氨酸可以看作为三齿配位体,但本工作的结果并无证据支持羟基参与配位,然而在Cd-The-His体系中,Cd.Thr.His同它的1:2母体二元配合物相比表现了显著的稳定性,这可能显示了不同的配位状况.但这一点有待于进一步证实.     

pH-Metric studies on the binary and ternary complexes of oxovanadium(IV)

The interaction of oxovanadium(IV) with some hydroxy acids, salicylic (SA), 5-sulphosalicylic (SSA) and 8-hydroxyquinoline-5-sulphonic (HQSA) acids, has been studied potentiometrically. Further, pH-metric studies of the ternary systems, VO²⁺?HQSA-dicarboxylic or hydroxy acids (where dicarboxylic acids = phthalic and maleic acids and hydroxy acids =SA andSSA) have been carried out and the formation of 1∶1∶1 mixed complexes inferred from the potentiometric curves. The equilibrium, chelate formation and hydrolysis constants have been calculated in the case of binary systems. The ternary complexes have been found to be more stable as indicated by their formation constants.     

Structural and thermal characterization of ternary complexes of piroxicam and alanine with transition metals: uranyl binary and ternary complexes of piroxicam. Spectroscopic characterization and properties of metal complexes

Ternary Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and UO2(II) complexes with piroxicam (Pir) drug (H2L1) and dl-alanine (Ala) (HL2) and also the binary UO2(II) complex with Pir were studied. The structures of the complexes were elucidated using elemental, IR, molar conductance, magnetic moment, diffused reflectance and thermal analyses. The UO2(II) binary complex was isolated in 1:2 ratio with the formula [UO2(H2L)2](NO3)2. The ternary complexes were isolated in 1:1:1 (M:H2L1:L2) ratios. The solid complexes were isolated in the general formulae [M(H2L)(L2)(Cl)n(H2O)m].yH2O (M=Fe(III) (n=2, m=0, y=1), Co(II) (n=1, m=1, y=2) and Ni(II) (n=1, m=1, y=0)); [M(H2L)(L2)](X)z.yH2O (M=Cu(II) (X=AcO, z=1, y=0), Zn(II) (X=AcO, z=1, y=3) and UO2(II) (X=NO3, z=1, y=2)). Pir behaves as a neutral bidentate ligand coordinated to the metal ions via the pyridine-N and carbonyl-O groups, while Ala behaves as a uninegatively bidentate ligand coordinated to the metal ions via the deprotonated carboxylate-O and amino-N. The magnetic and reflectance spectral data show that the complexes have octahedral geometry except Cu(II) and Zn(II) complexes have tetrahedral structures. The thermal decomposition of the complexes was discussed in relation to structure, and the thermodynamic parameters of the decomposition stages were evaluated.     

Membrane properties of binary and ternary systems of ganglioside GM1/dipalmitoylphosphatidylcholine/dioleoylphosphatidylcholine

The membrane properties of the ganglioside GM1 (GM1)/dioleoylphosphatidylcholine (DOPC) binary system and GM1/dipalmitoylphosphatidylcholine (DPPC)/DOPC ternary system were investigated using surface pressure measurements and atomic force microscopy (AFM), and the effect of surface pressure on the properties of the membranes was examined. Mixed GM1/DPPC/DOPC monolayers were deposited on mica using the Langmuir-Blodgett technique for AFM. GM1 and DOPC were immiscible and phase-separated. The AFM image of the GM1/DOPC (1:1) monolayer showed island-like GM1 domains embedded in the DOPC matrix. There was no morphological change on varying surface pressure. The surface pressure-area isotherm of the GM1/DPPC/DOPC (2:9:9) monolayer showed a two-step collapse as in the DPPC/DOPC (1:1) monolayer. The AFM image for the GM1/DPPC/DOPC monolayer showed DPPC and GM1 domains in the DOPC matrix, and the DPPC-rich phase containing GM1 showed a percolation pattern the same as the GM1/DPPC (1:9) monolayer. The percolation pattern in the GM1/DPPC/DOPC monolayer changed as the surface pressure was varied. The surface pressure-responsive change in morphology of GM1 was affected by the surrounding environment, suggesting that the GM1 localized in each organ has a specific role.     

Dication induced stabilization of gas-phase ternary beta-cyclodextrin inclusion complexes observed by electrospray mass spectrometry

Electrospray mass spectrometry (ES-MS) is an important tool for characterization of non-covalent binding in the gas phase. In this study, iron (II) has been introduced as a dication to enhance the detection of cyclodextrin (CD) plus aromatic compound complexes in ES-MS. Evidence that a novel ternary complex comprised of one beta-CD, one iron (II) and one toluene exists as an inclusion complex has been compiled via ES-MS and ES-MS/MS experiments as well as by a computational approach. This evidence strongly suggests that iron (II) serves to modify the conformation of the beta-CD ring, and that toluene inclusion is stabilized by dication interaction with the toluene pi-system and by crimping of the beta-CD ring leading to stronger van der Waals interactions with toluene. Mg(II), another dication of similar radius, showed similar behavior, while added group one cations (H(+) and Na(+)) were ineffective at producing observable ions representative of the complex. The ternary beta-CD complex with iron (II) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) has also been examined. ES-MS and ES-MS/MS experiments suggest that it is the polar portion of 2,4,5-T (i.e., the carboxylic acid moiety) that is favored for inclusion in the beta-CD cavity, rather than the non-polar aromatic part.     

Calculation of properties of ternary liquid mixtures on the basis of properties of binary solutions

Various methods of calculating properties of ternary systems using the properties of binary solutions have been analyzed on the basis of experimental and published data.     

Physical properties of binary cerium gallides and ternary cerium-germanium gallides

Binary and ternary cerium-gallium germanides have been synthesized by arc melting and the existence of five binary cerium-gallium compounds and four ternary phases Ce₂Ge_5.4Ga_1.6, Ce₄Ge₇Ga₄, CeGeGa and Ce₅GeGa₂ has been confirmed from X-ray powder diffraction analysis. Low temperature magnetization and electrical resistivity data in the temperature range from 2 to 300 K reveal the absence of magnetic ordering except for CeGa, which was found to be antiferromagnetic below T_N = 7 K. Effective paramagnetic moments in all cases are close to a tripositive behaviour of cerium with a small tendency for the effective moments in the binary cerium gallides to move towards smaller values when the gallium content decreases in close correspondence with the interatomic cerium distances.     

Spectral and photochemical properties of bifunctional compounds and their complexes

Quantum yields of the step-by-step photocyclization of diphenylamine (DPA) derivatives Ph₂N−(CH₂)n−NPh₂,n=3–6, 9, to the corresponding α,ω-di(carbazolyl)alkanes were measured. Atn>3, the presence of the second DPA group had no effect on the cyclization of the first DPA group; however, cyclization of the second DPA group was retarded after cyclization of the first DPA group. The effect was explained by quenching of the excited DPA group by the carbazole group newly formed in the semi-cyclic compound. For disubstituted propane (n=3), the mutual influence of the two groups at both stages of the reaction was found. For Part 1, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1510–1515, August, 1999.     

Influence of the chain composition on the thermodynamic properties of binary and ternary polymer solutions

Thermodynamic properties of binary and ternary polymer solutions (one or two uncharged polymers in one solvent) were studied. Poly(vinyl pyrrolidone) (PVP), fully hydrolyzed poly(vinyl alcohol) (PVA) homopolymers, and water-soluble poly(vinyl alcohol-co-vinyl acetal, -vinyl propional, and -vinyl butiral) copolymers with various acetal content and chain structure, respectively, were used in the experiments. The hydrophilic/hydrophobic character of the PVA-based macromolecules and their compatibility with the PVP homopolymer were systematically regulated by changing the chemical structure of the copolymers (acetal content and/or length of side chains). The water activities in binary and ternary solutions of the chemically different polymers were determined by a gel-deswelling method developed here for ternary solutions. On the basis of the Flory-Huggins theory, the relevant solvent-segment and segment-segment pair interaction parameters (chi) have been calculated. The chi12 segment-solvent interaction parameters proved to be sensitive indicators for changes in the chemical structure of the copolymers. With increase of either the acetal content or the length of side chains in the copolymer, chi12 approached the value characteristic of a theta condition. No significant differences could be revealed in the segment-segment interaction parameters obtained for the PVP-copolymer mixtures with various acetal derivatives, when the chi12 and chi13 interaction parameters determined in binary solutions were used in the calculations for chi23. Determination of the parameters chi1,23 as suggested by Panayiotou, however, showed that increasing the acetal content or the length of the hydrophobic side chains in the copolymer resulted in a reduction in the interaction between the PVA "acetals" and PVP molecules.     

Coordination properties of cefadroxil antibiotic: synthesis and equilibrium studies of the binary and ternary complexes involving amino acids and DNA units

The formation equilibria for the binary complexes of Cu(II), Ni(II), Co(II), Zn(II), Mn(II), Hg(II), Cd(II), Ca(II), and Mg(II) with cefadroxil (Cef) and for the ternary complexes Cu(Cef)(L), where L refers to amino acid or DNA, were investigated. The protonation constants of cefadroxil and formation constants of the formed complexes were determined at 25 degrees C and mu = 0.1 M NaNo(3). Cooper(II) and cobalt(II) complexes of cefadroxil were isolated in solid state and characterized by elemental analysis, infrared and electronic spectral, conductivity and magnetic measurement.     

Synthesis, luminescence properties and energy transfer of binary and ternary rare earth complexes with aromatic acids and 1,10-phenanthroline

A series of binary and ternary rare earth (Gd, Eu, Tb) complexes with ortho hydroxyl benzoic acid, para aminobenzoic acid, nicotinic acid and 1,10-phenanthroline were synthesized. Phosphorescence spectra and lifetimes of Gd complexes were measured and the lowest triplet state energies of gadolinium binary complexes and the intramolecular energy transfer efficiencies were determined. The luminescence properties and energy transfer process of Eu3+and Tb3+ complexes were discussed.     

Differential-pulse voltammetric studies on some binary and ternary copper(II) amino acid complexes

Some selected binary and ternary copper(II) amino acid complexes are investigated by differential-pulse voltammetry and the results are discussed. These results are compared with cyclic voltammetric results of the same systems.