International Journal of Molecular Sciences

212 KiB

Open AccessArticle

The SPASIBA Force Field for Studying Iron-Tannins Interactions : Application to Fe³⁺ /Fe²⁺ Catechol Complexe

by D. Yapo-Kicho, P. Lagant and G. Vergoten

Int. J. Mol. Sci. 2007, 8(3), 259-272; https://doi.org/10.3390/i8030259 - 30 Mar 2007

Cited by 6 | Viewed by 11204

The SPASIBA force field parameters have been obtained for Fe³⁺ /Fe²⁺ -Oxygeninteractions occuring between non-heminic iron and hydroxyl groups of polyphenols foundin tannins. These parameters were derived from normal modes analyses based on quantumchemical calculations using the Density Functional Theory (DFT). [...] Read more.

The SPASIBA force field parameters have been obtained for Fe³⁺ /Fe²⁺ -Oxygeninteractions occuring between non-heminic iron and hydroxyl groups of polyphenols foundin tannins. These parameters were derived from normal modes analyses based on quantumchemical calculations using the Density Functional Theory (DFT). Four models involvingcomplexation of iron with water ([Fe(H₂O)₆]³⁺ , [Fe(H₂O)6]²⁺ ) and with cathechol molecules([Fe(cat)₂(H₂O)₂]^-1, [Fe(cat)₂(H₂O)₂]^-2) were studied using the Density Functional Theoryand the B3LYP hybrid functional under high spin states of iron. Full article

(This article belongs to the Section Physical Chemistry, Theoretical and Computational Chemistry)

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811 KiB

Open AccessArticle

Crystal Engineering Based on Polymeric Hydrogen-Bonded Supramolecules by Self-Assembling of 9, 10-Bis(3,5- dihydroxyphenyl)anthracene and 2,2′,4,4′- Tetrahydroxybenzophenone with Bipyridines

by Xiaokang Li, Lvyin Zhen, Yulan Fan, Xiaolin Fan and Qingdao Zeng

Int. J. Mol. Sci. 2007, 8(3), 241-258; https://doi.org/10.3390/i8030241 - 16 Mar 2007

Cited by 4 | Viewed by 9284

Abstract

9, 10-bis(3,5-dihydroxyphenyl)anthracene (BDHA) and 2,2′,4,4′-tetrahydroxybenzophenone (THB) are crystallized with bipyridine bases 4,4 ́-bipyridyl(bipy), 1,2-bis(4-pyridyl)ethane (bipy-eta), 1,2-di(4-pyridyl)ethylene (dipy-ete), 1,3-di(4-pyridyl)propane (dipy-pra), 4,4 ́-dipyridyl sulfide (dipy-sul), and 4,4 ́-dipyridyl disulfide(dipy-dis) to afford molecular complexes (BDHA)·(bipy)₂ 1, (BDHA)·(bipy-eta)₂ 2,(BDHA)_0.5·(dipy-pra)·CH₃CH₂OH [...] Read more.

9, 10-bis(3,5-dihydroxyphenyl)anthracene (BDHA) and 2,2′,4,4′-tetrahydroxybenzophenone (THB) are crystallized with bipyridine bases 4,4 ́-bipyridyl(bipy), 1,2-bis(4-pyridyl)ethane (bipy-eta), 1,2-di(4-pyridyl)ethylene (dipy-ete), 1,3-di(4-pyridyl)propane (dipy-pra), 4,4 ́-dipyridyl sulfide (dipy-sul), and 4,4 ́-dipyridyl disulfide(dipy-dis) to afford molecular complexes (BDHA)·(bipy)₂ 1, (BDHA)·(bipy-eta)₂ 2,(BDHA)_0.5·(dipy-pra)·CH₃CH₂OH 3, (BDHA)_0.5·(dipy-sul)·H₂O 4, (BDHA)_0.5·(dipy-dis)·CH₃CH₂OH 5 and (THB)·(dipy-ete)₂·H₂O 6. The crystal structures of 1–6 have beendetermined by single-crystal X-ray diffraction. All these molecular complexes exhibitpolymeric supramolecular structures via O–H···N or O–H···O hydrogen-bonding. 1 and 2form infinitely rectangular macrocycles linked with one another, whose sizes are ca.12.477 å× 4.802 å and ca.14.575 å × 4.809 å, respectively. 3, 5 and 6 form the one-dimensionalzigzag chain structure. 4 forms a ladder structure, and two dipy-sul molecules were includedin a frame. Full article

(This article belongs to the Section Molecular Recognition)

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298 KiB

Open AccessArticle

Effects of Acetazolamide Combined with or without NaHCO₃ on Suppressing Neoplasm Growth, Metastasis and Aquaporin-1 (AQP1) Protein Expression

by Xue-Jun Li, Yang Xiang, Bing Ma and Xiao-Qiang Qi

Int. J. Mol. Sci. 2007, 8(3), 229-240; https://doi.org/10.3390/i8030229 - 13 Mar 2007

Cited by 13 | Viewed by 9566

Abstract

This study was made to explore the effects of acetazolamide on tumor growth,metastasis and the possible mechanisms. The mice bearing with Lewis lung carcinomaswere taken as the animal model. The effects of acetazolamide were compared with thecombination treatment of NaHCO₃ on tumor [...] Read more.

This study was made to explore the effects of acetazolamide on tumor growth,metastasis and the possible mechanisms. The mice bearing with Lewis lung carcinomaswere taken as the animal model. The effects of acetazolamide were compared with thecombination treatment of NaHCO₃ on tumor growth, metastasis and carbonic anhydraseactivity in lung and tumor tissues using imidazole-Tris technique. And also the possible roleof AQP1 in tumor tissues was investigated by Western blot and immuno-histochemicalanalysis. Results showed that acetazolamide alone could sharply reduce the number of lungmetastasis and primary tumor growth, and appeared in a dose-dependent manner.Acetazolamide significantly inhibited carbonic anhydrase activity in tumor tissue. After theaddition of NaHCO₃, the suppression of acetazolamide on tumor growth, number ofmetastasis and carbonic anhydrase activity in primary tumor tissue could not be alteredsignificantly, but the inhibitory rate of metastasis in lung and carbonic anhydrase activity inlung tissue appeared to show a reversal trend in the dose dependency from the acetazolamidetreatment alone. The exactly mechanisms need to be clarified in future. Western blot andimmunohistochemical analysis demonstrated that AQP1 expression in the tumor tissue washigher than both tissue of normal and treated with acetazolamide treatment alone.Combination with NaHCO₃ could not synergistically inhibit the expression of AQP1 withacetazolamide. The results suggested that the mechanism of acetazolamide on anti-tumor especially on its anti-metastasis actions might partly involve either inhibiting the carbonic anhydrase activity or reducing AQP1 water channel protein expression, whatever if treated with or without NaHCO₃. Full article

(This article belongs to the Special Issue Interaction of Biological Molecules)

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4170 KiB

Open AccessArticle

Antiproliferative Activity of β-Hydroxy-β-Arylalkanoic Acids

by Sanda P. Dilber, Željko S. Žižak, Tatjana P. Stanojković, Zorica D. Juranić, Branko J. Drakulić and Ivan O. Juranić

Int. J. Mol. Sci. 2007, 8(3), 214-228; https://doi.org/10.3390/i8030214 - 13 Mar 2007

Cited by 8 | Viewed by 11737

Abstract

Article describes the synthesis of fifteen β-hydroxy-β-arylalkanoic acids byReformatsky reaction using the 1-ethoxyethyl-2-bromoalkanoates, aromatic or cycloalkylketones or aromatic aldehydes. The short survey of previously reported synthetic proceduresfor title compounds, is given. The majority of obtained compounds exert antiproliferativeactivity in vitro toward human: HeLa, [...] Read more.

Article describes the synthesis of fifteen β-hydroxy-β-arylalkanoic acids byReformatsky reaction using the 1-ethoxyethyl-2-bromoalkanoates, aromatic or cycloalkylketones or aromatic aldehydes. The short survey of previously reported synthetic proceduresfor title compounds, is given. The majority of obtained compounds exert antiproliferativeactivity in vitro toward human: HeLa, Fem-X cells, K562, and LS174 cells, having IC₅₀values from 62.20 to 205 μM. The most active compound is 3-OH-2,2-di-Me-3-(4-biphenylyl)-butanoic acid, having the IC₅₀ value 62.20 μM toward HeLa cells. Sevenexamined compounds did not affect proliferation of healthy human blood peripheralmononuclear cells (PBMC and PBMC PHA), IC₅₀ > 300 μM. The preliminary QSARresults show that estimated lipophilicity of compounds influences their antiproliferativeactivity in the first place. The ability of dehydration, and the spatial arrangement ofhydrophobic portion, HBD and HBA in molecules are has almost equal importance aslipophilicity. Full article

(This article belongs to the Section Physical Chemistry, Theoretical and Computational Chemistry)

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149 KiB

Open AccessArticle

Expression of VDAC Regulated by Extracts of Limonium sinense Ktze root Against CCl₄-induced Liver Damage

by Xinhui Tang, Jing Ga, Jin Chen, Lizhi Xu, Yahong Tang, Huan Dou, Wen Yu and Xiaoning Zhao

Int. J. Mol. Sci. 2007, 8(3), 204-213; https://doi.org/10.3390/i8030204 - 9 Mar 2007

Cited by 8 | Viewed by 8891

Abstract

The expression of mitochondrial voltage-dependent anion channels (VDAC) mayunderlie the protective effects of Limonium sinense (Girard) Ktze root extracts (LSE) againstcarbon tetrachloride-induced liver damage. Pretreatment of mice with 100 mg/kg, 200mg/kg or 400 mg/kg LSE significantly blocked the carbon tetrachloride-induced increase inboth serum [...] Read more.

The expression of mitochondrial voltage-dependent anion channels (VDAC) mayunderlie the protective effects of Limonium sinense (Girard) Ktze root extracts (LSE) againstcarbon tetrachloride-induced liver damage. Pretreatment of mice with 100 mg/kg, 200mg/kg or 400 mg/kg LSE significantly blocked the carbon tetrachloride-induced increase inboth serum aspartate aminotransferase (sAST) and serum alanine aminotransferase (sALT)levels. Ultrastructural observations by electron microscope confirmed hepatoprotection,showing decreased nuclear condensation, ameliorated mitochondrial fragmentation of thecristae and less lipid deposition. Pretreatment with LSE prevented the decrease of thedisruption of mitochondrial membrane potential (15.3%) observed in the liver of the carbontetrachloride-insulted mice, further demonstrating the mitochondrial protection. In addition,LSE treatment (100-400 mg/kg) significantly increased both transcription and translation ofVDAC. The above data suggests that LSE mitigates the damage to liver mitochondriainduced by carbon tetrachloride, possibly through regulation of mitochondrial VDAC, one ofthe most important proteins in the mitochondrial outer membrane. Full article

(This article belongs to the Special Issue Interaction of Biological Molecules)

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110 KiB

Open AccessArticle

Results from the Use of Molecular Descriptors Family on Structure Property/Activity Relationships

by Lorentz Jäntschi and Sorana-Daniela Bolboacă

Int. J. Mol. Sci. 2007, 8(3), 189-203; https://doi.org/10.3390/i8030189 - 9 Mar 2007

Cited by 21 | Viewed by 9174

Abstract

The aim of the paper is to present the results obtained by utilization of an originalapproach called Molecular Descriptors Family on Structure-Property (MDF-SPR) andStructure-Activity Relationships (MDF-SAR) applied on classes of chemical compoundsand its usefulness as precursors of models elaboration of new compounds with [...] Read more.

The aim of the paper is to present the results obtained by utilization of an originalapproach called Molecular Descriptors Family on Structure-Property (MDF-SPR) andStructure-Activity Relationships (MDF-SAR) applied on classes of chemical compoundsand its usefulness as precursors of models elaboration of new compounds with betterproperties and/or activities and low production costs. The MDF-SPR/MDF-SARmethodology integrates the complex information obtained from compound’s structure inunitary efficient models in order to explain properties/activities. The methodology has beenapplied on a number of thirty sets of chemical compounds. The best subsets of moleculardescriptors family members able to estimate and predict property/activity of interest wereidentified and were statistically and visually analyzed. The MDF-SPR/MDF-SAR modelswere validated through internal and/or external validation methods. The estimation andprediction abilities of the MDF-SPR/MDF-SAR models were compared with previousreported models by applying of correlated correlation analysis, which revealed that theMDF-SPR/MDF-SAR methodology is reliable. The MDF-SPR/MDF-SAR methodologyopens a new pathway in understanding the relationships between compound’s structure andproperty/activity, in property/activity prediction, and in discovery, investigation andcharacterization of new chemical compounds, more competitive as costs andproperty/activity, being a method less expensive comparative with experimental methods. Full article

(This article belongs to the Special Issue Interaction of Biological Molecules)

144 KiB

Open AccessArticle

Rheological Behaviors of Polyacrylonitrile/1-Butyl-3- Methylimidazolium Chloride Concentrated Solutions

by Weiwei Liu, Lingyan Cheng, Hongyan Zhang, Yumei Zhang, Huaping Wang and Mingfang Yu

Int. J. Mol. Sci. 2007, 8(3), 180-188; https://doi.org/10.3390/i8030180 - 7 Mar 2007

Cited by 40 | Viewed by 11544

Abstract

One of the room temperature ionic liquids (RTILs), 1-butyl-3-methylimidazoliumchloride ([BMIM]Cl) was chosen to prepare the concentrated solutions of Polyacrylonitrile(PAN). The rheological behaviors of the solutions were measured with rotational rheometryunder different conditions, including temperatures, concentration, and molecular weight ofPAN. The solutions exhibited shear-thinning [...] Read more.

One of the room temperature ionic liquids (RTILs), 1-butyl-3-methylimidazoliumchloride ([BMIM]Cl) was chosen to prepare the concentrated solutions of Polyacrylonitrile(PAN). The rheological behaviors of the solutions were measured with rotational rheometryunder different conditions, including temperatures, concentration, and molecular weight ofPAN. The solutions exhibited shear-thinning behaviors, similar to that of PAN/DMFsolutions. The viscosities decreased with the increasing of shear rates. However, theviscosity decreased sharply at high shear rates when the concentration was up to 16wt%. Thedependence of the viscosity on temperature was analyzed through the determination of theapparent activation energy. Unusually, the viscosity of solutions of higher concentration islower than that of lower concentration. Similarly, the viscosity of low molecular weightPAN was higher than high molecular weight PAN at high shear rates. The dynamicrheological measurement indicates the loss modulus is much higher than storage modulus.The trend of complex viscosity is similar with the result of static rheological measurement.The interaction between PAN and ionic liquid [BMIM]Cl was discussed. Full article

(This article belongs to the Special Issue Ionic Liquids)

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Int. J. Mol. Sci., Volume 8, Issue 3 (March 2007) – 7 articles , Pages 180-272

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