Multi-wavelength spectrophotometric determination of acidity constant of some newly synthesized Schiff bases and their QSPR study

Hemmateenejad, Bahram; Emami, Leila; Sharghi, Hashem

doi:10.1016/j.saa.2009.10.037

Cited by 11 publications

(9 citation statements)

References 38 publications

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“…Phase solubility diagrams are useful tools to study inclusion complexes between poorly soluble compounds and cyclodextrins, since they not only provide a quantitative measure of the solubilizing ability of the host but also allow the corresponding stability constant to be calculated by analyzing the solubility curves . Figure shows the phase solubility diagrams of HCT with β-CD in aqueous solutions determined at various pH values and at different temperatures.…”

Section: Resultsmentioning

confidence: 99%

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Characterization of the Hydrochlorothiazide: β-Cyclodextrin Inclusion Complex. Experimental and Theoretical Methods

et al. 2012

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Hydrochlorothiazide (HCT) is one of the most commonly prescribed antihypertensive drugs. In an attempt to gain an insight into the physicochemical and molecular aspects controlling the complex architecture of native β-cyclodextrin (β-CD) with HCT, we performed multiple-temperature-pH isothermal titration calorimetric measurements of the HCT:β-CD system, together with proton nuclear magnetic resonance spectroscopy ((1)H NMR), phase solubility analysis, and molecular modeling methods. The A(L)-type diagrams, obtained at different pH values and temperatures, suggested the formation of soluble 1:1 inclusion complexes of β-CD with HCT. The corresponding stability constants (K(1:1)) were determined by phase solubility studies and compared with those obtained by ITC, with good agreement between these two techniques being found. The three-dimensional array of the complex was studied by (1)H NMR and molecular modeling methods. Both techniques confirmed the formation of the inclusion complex, with good agreement between the experimental and theoretical techniques regarding the HCT binding mode to β-CD. Also, the forces involved in the association process were determined, both from the thermodynamic parameters obtained by ITC (association enthalpy, binding constant, Gibbs free energy, and entropy) and from energetic decomposition analyses derived from computational methods. We concluded that the formation of the HCT:β-CD complex was enthalpy driven, with the inclusion mode of HCT being highly dependent on its ionization state. In all cases, sustained hydrogen bond interactions with hydroxyl groups of β-CD were identified, with the solvation energy limiting the affinity. Regarding the pH and temperature dependence, lower affinity constants were found at higher HCT ionization states and temperatures.

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Section: Resultsmentioning

confidence: 99%

“…Phase solubility studies were carried out according to a method described by Higuchi and Connors. 38 An excess amount of HCT was mixed in a series of buffer solutions (pH 3, 5.5, 6.8, 7.4, 8, 10) containing increasing amounts of β-CD (0−12 mM) and subjected to vortex mixing. After dissolution the equilibrium was reached.…”

Section: ■ Introductionmentioning

confidence: 99%

Characterization of the Hydrochlorothiazide: β-Cyclodextrin Inclusion Complex. Experimental and Theoretical Methods

et al. 2012

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“…The intramolecular protonation of the amino function creates an ammonium system which is capable of a strong supramolecular interaction with the strong hydrogen bonding acceptor GBL. 22 The influence of the microporosity of the material seems to play a minor role in this particular case.…”

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confidence: 87%

Direct gravimetric sensing of GBL by a molecular recognition process in organic cage compounds

et al. 2013

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“…The most important phase in constructing QSAR models is the suitable description of the structural and physicochemical properties of chemical structures ( 12 13 14 15 ). These properties called molecular descriptors have a high impact on the pharmacological properties of a compound ( 16 17 18 19 ). Molecular descriptors have been classified into different groups including physiochemical, constitutional, geometrical, topological, and quantum chemical descriptors.…”

Section: Introductionmentioning

confidence: 99%

Quinazoline analogues as cytotoxic agents; QSAR, docking, and in silico studies

et al. 2021

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Background and purpose: Synthesis and investigation of pharmacological activity of novel compounds are time and money-consuming. However, computational techniques, docking, and in silico studies have facilitated drug discovery research to design pharmacologically effective compounds. Experimental approach: In this study, a series of quinazoline derivatives were applied to quantitative structure-activity relationship (QSAR) analysis. A collection of chemometric methods were conducted to provide relations between structural features and cytotoxic activity of a variety of quinazoline derivatives against breast cancer cell line. An in silico -screening was accomplished and new impressive lead compounds were designed to target the epidermal growth factor receptor (EGFR)-active site based on a new structural pattern. Molecular docking was performed to delve into the interactions, free binding energy, and molecular binding mode of the compounds against the EGFR target. Findings/Results: A comparison between different methods significantly indicated that genetic algorithm-partial least-squares were selected as the best model for quinazoline derivatives. In the current study, constitutional, functional, chemical, resource description framework, 2D autocorrelation, and charge descriptors were considered as significant parameters for the prediction of anticancer activity of quinazoline derivatives. In silico screening was employed to discover new compounds with good potential as anticancer agents and suggested to be synthesized. Also, the binding energy of docking simulation showed desired correlation with QSAR and experimental data. Conclusion and implications: The results showed good accordance between binding energy and QSAR results. Compounds Q 1 -Q 30 are desired to be synthesized and applied to in vitro evaluation.

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Multi-wavelength spectrophotometric determination of acidity constant of some newly synthesized Schiff bases and their QSPR study

Cited by 11 publications

References 38 publications

Characterization of the Hydrochlorothiazide: β-Cyclodextrin Inclusion Complex. Experimental and Theoretical Methods

Characterization of the Hydrochlorothiazide: β-Cyclodextrin Inclusion Complex. Experimental and Theoretical Methods

Direct gravimetric sensing of GBL by a molecular recognition process in organic cage compounds

Quinazoline analogues as cytotoxic agents; QSAR, docking, and in silico studies

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