scholarly journals Equilibrium and Kinetic Investigations of the Interaction of Model Platinum(II) Complex with DNA Constituents in Reference to the Antitumour Activity: Complex-Formation Reactions of [Pd(N,N-diethylethylenediamine)(H2O)2]2+with Ligands of Biological Significance and Displacement Reactions of DNA Constituents

2009 ◽  
Vol 2009 ◽  
pp. 1-10 ◽  
Author(s):  
Eman Mohamed Shoukry
Keyword(s):  
Concentration Distribution ◽  
Antitumour Activity ◽  
Equilibrium Constants ◽  
Biological Significance ◽  
Dicarboxylic Acids ◽  
Base Hydrolysis ◽  
Biologically Relevant ◽  
Dna Constituents ◽  
Displacement Reactions ◽  
Mechanism Of Hydrolysis

The[Pd(DEEN)Cl2]and[Pt(DEEN)Cl2]complexes were synthesized and characterized whereDEEN=N,N-diethylethylenediamine. The stoichiometry and stability of the complexes formed between various biologically relevant ligands (amino acids, peptides, DNA constituents and dicarboxylic acids) and[Pd(DEEN)(H2O)2]2+were investigated at37∘Cand 0.16 M ionic strength. The stability constant of the complexes formed in solution were determined and the binding centres of the ligands were assigned. The concentration distribution diagrams of the complexes were evaluated The equilibrium constants for the displacement of representative coordinated ligands such as inosine, glycine or methionine by cysteine were calculated and the concentration distribution diagrams of the various species were evaluated. The kinetics of base hydrolysis of free and coordinated S-methylcysteine methyl ester was investigated. The mechanism of hydrolysis was discussed.

scholarly journals The interaction of [Pd(N,N-dimethylaminopropylamine)(H2O)]2+ with dicarboxylic acids and inosine: Thermodynamic model for carboplatin drug

2012 ◽  
Vol 10 (4) ◽  
pp. 1253-1261 ◽  
Author(s):  
Mohamed Shehate ◽  
Mohamed Shoukry ◽  
Mona Ragab
Keyword(s):  
Dielectric Constant ◽  
Stability Constant ◽  
Equilibrium Constants ◽  
Chloride Ion ◽  
Dicarboxylic Acids ◽  
Ion Concentration ◽  
Antitumour Agents ◽  
Effect Of Solvent ◽  
Dna Constituents ◽  
The Stability

AbstractThe Pd(DMPA)Cl2 complex, where DMPA = N,N-dimethylaminoproylamine, was synthesized and characterized. The stoichiometry and stability constants of the complexes formed between various dicarboxylic acids and [Pd(DMPA)(H2O)2]2+ were investigated. The effect of solvent dielectric constant, chloride ion concentration of the medium and temperature on the stability constant of the cyclobutanedicaroxylic acid (CBDCA) complex was investigated. The equilibrium constants for the displacement of coordinated CBDCA by inosine, taken as an example of DNA constituents, were calculated. The results are expected to contribute to the chemistry of antitumour agents.

Base hydrolysis of trans-Halogenoamminebis(dimethylglyoximato) (III). Complexes

1969 ◽  
Vol 22 (12) ◽  
pp. 2569 ◽  
Author(s):  
SC Chan ◽  
PY Leung
Keyword(s):  
Equilibrium Constants ◽  
Base Hydrolysis ◽  
Hydroxide Ion ◽  
First Order ◽  
Rate Determining Step ◽  
Rapid Formation ◽  
Pseudo First Order ◽  
Conjugate Bases ◽  
Hydrolysis Of ◽  
Conjugate Base

The disappearance of trans-[Co(LH)2(NH3)X] (LH = dimethylglyoximate ion, X = chloride or bromide) has been studied in aqueous solutions over a range of alkali concentrations at various temperatures. The kinetics were done with excess of hydroxide ion at a constant ionic strength so that pseudo first-order rate constants were obtained in all the runs. The results were interpreted in terms of the rapid formation of a pre- equilibrium species which then reacts in a rate-determining step to give products. The relatively large equilibrium constants support a conjugate-base pre-equilibrium, in which the proton is lost from oxygen, while the relatively low reactivities of the conjugate-bases are consistent with the absence of electropositive electromeric effects. The similarity in the reactivities of the chloro and the bromo conjugate-bases suggests the possibility of an SN2CB mechanism.

scholarly journals Technical note: Estimating aqueous solubilities and activity coefficients of mono- and <i>α</i>,<i>ω</i>-dicarboxylic acids using COSMO<i>therm</i>

2020 ◽  
Vol 20 (21) ◽  
pp. 13131-13143
Author(s):  
Noora Hyttinen ◽  
Reyhaneh Heshmatnezhad ◽  
Jonas Elm ◽  
Theo Kurtén ◽  
Nønne L. Prisle
Keyword(s):  
Activity Coefficients ◽  
Equilibrium Constants ◽  
Hydrate Formation ◽  
Dicarboxylic Acids ◽  
Aqueous Solubility ◽  
Technical Note ◽  
Acid Water ◽  
Monocarboxylic Acids ◽  
Wide Range ◽  
Experimental Values

Abstract. We have used the COSMOtherm program to estimate activity coefficients and solubilities of mono- and α,ω-dicarboxylic acids and water in binary acid–water systems. The deviation from ideality was found to be larger in the systems containing larger acids than in the systems containing smaller acids. COnductor-like Screening MOdel for Real Solvents (COSMO-RS) underestimates experimental monocarboxylic acid activity coefficients by less than a factor of 2, but experimental water activity coefficients are underestimated more especially at high acid mole fractions. We found a better agreement between COSMOtherm-estimated and experimental activity coefficients of monocarboxylic acids when the water clustering with a carboxylic acid and itself was taken into account using the dimerization, aggregation, and reaction extension (COSMO-RS-DARE) of COSMOtherm. COSMO-RS-DARE is not fully predictive, but fit parameters found here for water–water and acid–water clustering interactions can be used to estimate thermodynamic properties of monocarboxylic acids in other aqueous solvents, such as salt solutions. For the dicarboxylic acids, COSMO-RS is sufficient for predicting aqueous solubility and activity coefficients, and no fitting to experimental values is needed. This is highly beneficial for applications to atmospheric systems, as these data are typically not available for a wide range of mixing states realized in the atmosphere, due to a lack of either feasibility of the experiments or sample availability. Based on effective equilibrium constants of different clustering reactions in the binary solutions, acid dimer formation is more dominant in systems containing larger dicarboxylic acids (C5–C8), while for monocarboxylic acids (C1–C6) and smaller dicarboxylic acids (C2–C4), hydrate formation is more favorable, especially in dilute solutions.

Recent Progress in Chemistry of β-Lactams

2019 ◽  
Vol 16 (6) ◽  
pp. 544-567 ◽  
Author(s):  
Japheth O. Ombito ◽  
Girija S. Singh
Keyword(s):  
Heterocyclic Compounds ◽  
Bond Cleavage ◽  
Biological Significance ◽  
Synthetic Methods ◽  
Biologically Relevant ◽  
Amino Esters ◽  
Ring Expansions ◽  
Amide Carbonyl ◽  
Amide Carbonyl Group ◽  
Lactam Ring

The &#946;-lactams constitute a well-known class of compounds having tremendous biological significance. Besides being a motif of biological interest, they serve as versatile synthons in organic chemistry. In fact, their easy accessibility in the laboratory by several methods combined with inherent reactivity of the &#946; -lactam ring due to ring-strain places it among the most sought for substrate in the arsenal of synthetic organic chemists. Several chemical reagents, heat, and light promote its ring-opening, ring-expansions and rearrangement reactions yielding a wide variety of biologically relevant nitrogen-containing acyclic and heterocyclic compounds. In recent years, the reactivity of differently functionalized &#946;-lactam rings towards diverse kinds of reagents has been investigated. These investigations exploit selective bond cleavage of the &#946;-lactam nucleus via N1-C2, C3- C4, C2-C3 or N1-C4 bond cleavage using simple reagents. The reduction of amide carbonyl group, thionation, and pyrolysis/photolysis have also been explored. These investigations have led to the discovery of many easy synthetic methods for biologically important classes of compounds such as &#946;-amino acids, &#946;-amino esters, amino sugars, amino alcohols, peptides, azetidines, and other heterocyclic compounds. This article discusses the advances made in the studies on the reactivity of &#946;- lactam ring during the last ten years.

Efficient Mining Frequent Closed Discriminative Biclusters by Sample-Growth

2013 ◽  
pp. 84-103
Author(s):  
Miao Wang ◽  
Xuequn Shang ◽  
Shaohua Zhang ◽  
Zhanhuai Li
Keyword(s):  
Gene Expression ◽  
Dna Microarray ◽  
Gene Expression Data ◽  
Biological Significance ◽  
Microarray Dataset ◽  
Experimental Results ◽  
Expression Data ◽  
Biologically Relevant ◽  
Almost All ◽  
Microarray Datasets

DNA microarray technology has generated a large number of gene expression data. Biclustering is a methodology allowing for condition set and gene set points clustering simultaneously. It finds clusters of genes possessing similar characteristics together with biological conditions creating these similarities. Almost all the current biclustering algorithms find bicluster in one microarray dataset. In order to reduce the noise influence and find more biological biclusters, the authors propose the FDCluster algorithm in order to mine frequent closed discriminative bicluster in multiple microarray datasets. FDCluster uses Apriori property and several novel techniques for pruning to mine biclusters efficiently. To increase the space usage, FDCluster also utilizes several techniques to generate frequent closed bicluster without candidate maintenance in memory. The experimental results show that FDCluster is more effective than traditional methods in either single micorarray dataset or multiple microarray datasets. This paper tests the biological significance using GO to show the proposed method is able to produce biologically relevant biclusters.

scholarly journals Money as tool, money as drug: The biological psychology of a strong incentive

2006 ◽  
Vol 29 (2) ◽  
pp. 161-209 ◽  
Author(s):  
Stephen E. G. Lea ◽  
Paul Webley
Keyword(s):  
Biological Psychology ◽  
Biological Significance ◽  
Reciprocal Altruism ◽  
Empirical Literature ◽  
Psychoactive Drugs ◽  
Human Species ◽  
Object Play ◽  
Biologically Relevant ◽  
Strong Incentive ◽  
Metaphorical Extension

Why are people interested in money? Specifically, what could be the biological basis for the extraordinary incentive and reinforcing power of money, which seems to be unique to the human species? We identify two ways in which a commodity which is of no biological significance in itself can become a strong motivator. The first is if it is used as a tool, and by a metaphorical extension this is often applied to money: it is used instrumentally, in order to obtain biologically relevant incentives. Second, substances can be strong motivators because they imitate the action of natural incentives but do not produce the fitness gains for which those incentives are instinctively sought. The classic examples of this process are psychoactive drugs, but we argue that the drug concept can also be extended metaphorically to provide an account of money motivation. From a review of theoretical and empirical literature about money, we conclude that (i) there are a number of phenomena that cannot be accounted for by a pure Tool Theory of money motivation; (ii) supplementing Tool Theory with a Drug Theory enables the anomalous phenomena to be explained; and (iii) the human instincts that, according to a Drug Theory, money parasitizes include trading (derived from reciprocal altruism) and object play.

Interaction of dipropyltin(IV) with amino acids, peptides, dicarboxylic acids and DNA constituents

2006 ◽  
Vol 59 (2) ◽  
pp. 193-206 ◽  
Author(s):  
A. A. Al-Najjar ◽  
M. M. A. Mohamed ◽  
M. M. Shoukry
Keyword(s):  
Amino Acids ◽  
Dicarboxylic Acids ◽  
Dna Constituents
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