International Journal of Molecular Sciences

1888 KiB

Open AccessArticle

Photoresist Derived Carbon for Growth and Differentiation of Neuronal Cells

by Hong Zhou, Jianhua Zhou, Anju Gupta and Tie Zou

Int. J. Mol. Sci. 2007, 8(8), 884-893; https://doi.org/10.3390/i8080884 - 27 Aug 2007

Cited by 14 | Viewed by 9173

Apoptosis or necrosis of neurons in the central nervous system (CNS) is thehallmark of many neurodegenerative diseases and Traumatic Brain Injury (TBI). Theinability to regenerate in CNS offers little hope for naturally repairing the damagedneurons. However, with the rapid development of new technologies, [...] Read more.

Apoptosis or necrosis of neurons in the central nervous system (CNS) is thehallmark of many neurodegenerative diseases and Traumatic Brain Injury (TBI). Theinability to regenerate in CNS offers little hope for naturally repairing the damagedneurons. However, with the rapid development of new technologies, regenerative medicineoffers great promises to patients with these disorders. Among many events for furtheradvancement of regenerative medicine, extracellular matrix (ECM) plays a critical role forcellular migration and differentiation. To develop a biocompatible and electricallyconductive substrate that can be potentially used to promote growth and regeneration ofneurons and to record intracellular and multisite signals from brain as a probe, a polymericprecursor – SPR 220.7 was fabricated by pyrolysis at temperatures higher than 700 oC.Human Neuroblastoma cells - SK-N-MC, SY5Y, mouse teratocarcinoma cells P-19 and ratPC12 cells were found to attach and proliferate on photoresist derived carbon film.Significantly, neuronal differentiation of PC12 cells induced by NGF was demonstrated byobserving cell shape and size, and measuring the length of neurites under SEM. Our resultsindicated that fabricated carbon could potentially be explored in regenerative medicine forpromoting neuronal growth and differentiation in CNS with neurodegeneration. Full article

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

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335 KiB

Open AccessArticle

A Spectral-SAR Model for the Anionic-Cationic Interaction in Ionic Liquids: Application to Vibrio fischeri Ecotoxicity

by Ana-Maria Lacrămă, Mihai V. Putz and Vasile Ostafe

Int. J. Mol. Sci. 2007, 8(8), 842-863; https://doi.org/10.3390/i8080842 - 23 Aug 2007

Cited by 54 | Viewed by 9614

Abstract

Within the recently launched the spectral-structure activity relationship (S-SAR)analysis, the vectorial anionic-cationic model of a generic ionic liquid is proposed, alongwith the associated algebraic correlation factor in terms of the measured and predictedactivity norms. The reliability of the present scheme is tested by [...] Read more.

Within the recently launched the spectral-structure activity relationship (S-SAR)analysis, the vectorial anionic-cationic model of a generic ionic liquid is proposed, alongwith the associated algebraic correlation factor in terms of the measured and predictedactivity norms. The reliability of the present scheme is tested by assessing the Hanschfactors, i.e. lipophylicity, polarizability and total energy, to predict the ecotoxicityendpoints of wide types of ionic liquids with ammonium, pyridinium, phosphonium,choline and imidazolium cations on the aquatic bacteria Vibrio fischeri. The results, whileconfirming the cationic dominant influence when only lipophylicity is considered,demonstrate that the anionic effect dominates all other more specific interactions. It wasalso proved that the S-SAR vectorial model predicts considerably higher activity for theionic liquids than for its anionic and cationic subsystems separately, in all consideredcases. Moreover, through applying the least norm-correlation path principle, the completetoxicological hierarchies are presented, unfolding the ecological rules of combined cationicand anionic influences in ionic liquid toxicity. Full article

(This article belongs to the Special Issue Ionic Liquids)

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3403 KiB

Open AccessReview

Developments in Molecular Recognition and Sensing at Interfaces

by Katsuhiko Ariga, Jonathan P. Hill and Hiroshi Endo

Int. J. Mol. Sci. 2007, 8(8), 864-883; https://doi.org/10.3390/i8080864 - 22 Aug 2007

Cited by 35 | Viewed by 10507

Abstract

In biological systems, molecular recognition events occur mostly withininterfacial environments such as at membrane surfaces, enzyme reaction sites, or at theinterior of the DNA double helix. Investigation of molecular recognition at model interfacesprovides great insights into biological phenomena. Molecular recognition at interfaces notonly [...] Read more.

In biological systems, molecular recognition events occur mostly withininterfacial environments such as at membrane surfaces, enzyme reaction sites, or at theinterior of the DNA double helix. Investigation of molecular recognition at model interfacesprovides great insights into biological phenomena. Molecular recognition at interfaces notonly has relevance to biological systems but is also important for modern applications suchas high sensitivity sensors. Selective binding of guest molecules in solution to hostmolecules located at solid surfaces is crucial for electronic or photonic detection of analytesubstances. In response to these demands, molecular recognition at interfaces has beeninvestigated extensively during the past two decades using Langmuir monolayers, self-assembled monolayers, and lipid assemblies as recognition media. In this review, advancesof molecular recognition at interfaces are briefly summarized. Full article

(This article belongs to the Section Molecular Recognition)

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404 KiB

Open AccessArticle

Antiplatelet Effect and Selective Binding to Cyclooxygenase (COX) by Molecular Docking Analysis of Flavonoids and Lignans

by Chien-Ming Wu, Shu-Chun Wu, Wan-Jung Chung, Hsien-Cheng Lin, Kun-Tze Chen, Yu-Chian Chen, Mei-Feng Hsu, Jwu-Maw Yang, Jih-Pyang Wang and Chun-Nan Lin

Int. J. Mol. Sci. 2007, 8(8), 830-841; https://doi.org/10.3390/i8080830 - 22 Aug 2007

Cited by 28 | Viewed by 12162

Abstract

The known flavonoids ginkgetin (1), taiwanhomoflavone A (2),taiwanhomoflavone B (3), and taiwanhomoflavone C (4) and eight known lignans:justicidin B (9), justicidin C (10), justicidin D (11), chinensinaphthol methyl ether (12),procumphthalide A (13), procumbenoside A (15), and ciliatosides A (16) and B (17) wereisolated [...] Read more.

The known flavonoids ginkgetin (1), taiwanhomoflavone A (2),taiwanhomoflavone B (3), and taiwanhomoflavone C (4) and eight known lignans:justicidin B (9), justicidin C (10), justicidin D (11), chinensinaphthol methyl ether (12),procumphthalide A (13), procumbenoside A (15), and ciliatosides A (16) and B (17) wereisolated from Cephalotaxus wilsoniana and Justicia species, respectively. The antiplateleteffects of the above constituents on human platelet-rich plasma (PRP) were evaluated. Ofthe compounds tested on human PRP, compounds 1, 4, 9, and 11 showed inhibition ofsecondary aggregation induced by adrenaline. Compound 1 had an inhibitory effect oncyclooxygenase-1 (COX-1). Molecular docking studies revealed that 1 and the related compounds apigenin (5), cycloheterophyllin (6), broussoflavone F (7), and quercetin (8) were docked near the gate of active site of COX-1. It indicated that the antiplatelet effect of 1, 4, 9, and 11 is partially owed to suppression of COX-1 activity and reduced thromboxane formation. Flavonoids, 1, 5, 6, 7, and 8 may block the gate of the active site of COX-1 and interfere the conversion of arachidonic acid to prostaglandin (PG) H₂ in the COX-1 active site. Full article

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339 KiB

Open AccessArticle

Molecular Mechanics Study of Nickel(II) Octaethylporphyrin Adsorbed on Graphite(0001)

by Maja Gruden-Pavlović, Sonja Grubišić, Matija Zlatar and Svetozar R. Niketić

Int. J. Mol. Sci. 2007, 8(8), 810-829; https://doi.org/10.3390/i8080810 - 21 Aug 2007

Cited by 14 | Viewed by 9696

Abstract

The effects of adsorption on the graphite(0001) surface on the nonplanar dis-tortions of nickel(II)octaethylporphyrin were studied by molecular mechanics (MM) ap-proach. Using the Consistent Force Field (CFF) program with previously developed pa-rameters for metalloporphyrins and supplemented to treat intermolecular interactions ge-ometry optimizations were [...] Read more.

The effects of adsorption on the graphite(0001) surface on the nonplanar dis-tortions of nickel(II)octaethylporphyrin were studied by molecular mechanics (MM) ap-proach. Using the Consistent Force Field (CFF) program with previously developed pa-rameters for metalloporphyrins and supplemented to treat intermolecular interactions ge-ometry optimizations were carried out for 43 conformations of 28 distinct conformers ofnickel(II)octaethylporphyrin. The stable energy-minimized conformers were stereochem-ically characterized, analyzed by the Normal-coordinate Structural Decomposition (NSD)method and compared with the available theoretical and experimental data for the isolatednickel(II)octaethylporphyrin structures. Full article

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

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193 KiB

Open AccessArticle

Measurement of Antioxidant Activity of Wine Catechins, Procyanidins, Anthocyanins and Pyranoanthocyanins

by Jan Muselík, María García-Alonso, María P. Martín-López, Milan Žemlička and Julián C. Rivas-Gonzalo

Int. J. Mol. Sci. 2007, 8(8), 797-809; https://doi.org/10.3390/i8080797 - 14 Aug 2007

Cited by 115 | Viewed by 15783

Abstract

Nowadays, there is considerable interest in finding out about antioxidants thatare consumed in the habitual diet. It is known that polyphenols are involved in reducing therisk of diseases associated with oxidative stress. The in vitro antioxidant activity of theprincipal wine polyphenolic compounds (catechins, [...] Read more.

Nowadays, there is considerable interest in finding out about antioxidants thatare consumed in the habitual diet. It is known that polyphenols are involved in reducing therisk of diseases associated with oxidative stress. The in vitro antioxidant activity of theprincipal wine polyphenolic compounds (catechins, procyanidins, anthocyanins andpyranoanthocyanins) was studied in this work. Four distinct methods were used to assessthe antioxidant capacity of the tested compounds: inhibition of peroxynitrite mediatedtyrosine nitration, TEAC (Trolox equivalent antioxidant capacity assay), FRAP (Ferricreducing/antioxidant power assay) and TBARS (thiobarbituric acid reactive substances)methods. In general, it could be concluded that procyanidins were, among the in vitrotested groups, the ones which showed more antioxidant capacity using the four differentmethods, followed by anthocyanins and pyranoanthocyanins. On the basis of the simpleregression testing, there was a statistically significant relationship between these differentmethods used in aqueous phase (r > 0.92). However, no correlation was found between theresults obtained in lipid media with the TBARS method and those obtained in the aqueousmedia (peroxynitrite scavenging activity, TEAC and FRAP methods). Full article

(This article belongs to the Special Issue Phenolics and Polyphenolics)

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129 KiB

Open AccessArticle

Consideration of the Factors Influencing the Specific Rates of Solvolysis of p-Methoxyphenyl Chloroformate

by Malcolm J. D’Souza, Darneisha Reed, Fumie Koyoshi and Dennis N. Kevill

Int. J. Mol. Sci. 2007, 8(8), 788-796; https://doi.org/10.3390/i8080788 - 09 Aug 2007

Cited by 13 | Viewed by 8196

Abstract

A recent correlations analysis of the specific rates of solvolysis of p-methoxyphenyl chloroformate (1) in 31 solvents using the three-term Grunwald-Winsteinequation led to a sensitivity (h) towards changes in the aromatic ring parameter (I) of0.85 0.15. This value, suggesting an appreciable contribution from [...] Read more.

A recent correlations analysis of the specific rates of solvolysis of p-methoxyphenyl chloroformate (1) in 31 solvents using the three-term Grunwald-Winsteinequation led to a sensitivity (h) towards changes in the aromatic ring parameter (I) of0.85 0.15. This value, suggesting an appreciable contribution from the hI term, is incontrast to the h value of 0.35 0.19 that was reported for the parent phenyl chloroformate(2). However, for 1, only two specific rate values were available for the importantfluoroalcohol containing solvents. Values are now reported for 13 additional solvents,12 of which have appreciable fluoroalcohol content. With all 44 solvents considered, it isfound that the solvolytic behavior indicated for 1 now parallels very closely that previouslyreported for 2. Full article

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

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177 KiB

Open AccessArticle

Protective Effect of Encapsulation in Fermentation of Limonene-contained Media and Orange Peel Hydrolyzate

by Mohammad Pourbafrani, Farid Talebnia, Claes Niklasson and Mohammad J. Taherzadeh

Int. J. Mol. Sci. 2007, 8(8), 777-787; https://doi.org/10.3390/i8080777 - 07 Aug 2007

Cited by 62 | Viewed by 11335

Abstract

This work deals with the application of encapsulation technology to eliminateinhibition by D-limonene in fermentation of orange wastes to ethanol. Orange peel wasenzymatically hydrolyzed with cellulase and pectinase. However, fermentation of thereleased sugars in this hydrolyzate by freely suspended S. cerevisiae failed due [...] Read more.

This work deals with the application of encapsulation technology to eliminateinhibition by D-limonene in fermentation of orange wastes to ethanol. Orange peel wasenzymatically hydrolyzed with cellulase and pectinase. However, fermentation of thereleased sugars in this hydrolyzate by freely suspended S. cerevisiae failed due to inhibitionby limonene. On the other hand, encapsulation of S. cerevisiae in alginate membranes wasa powerful tool to overcome the negative effects of limonene. The encapsulated cells wereable to ferment the orange peel hydrolyzate in 7 h, and produce ethanol with a yield of 0.44g/g fermentable sugars. Cultivation of the encapsulated yeast in defined medium wassuccessful, even in the presence of 1.5% (v/v) limonene. The capsules’ membranes wereselectively permeable to the sugars and the other nutrients, but not limonene. While1% (v/v) limonene was present in the culture, its concentration inside the capsules was notmore than 0.054% (v/v). Full article

(This article belongs to the Special Issue Biofuels R&D: Securing the Planet's Future Energy Needs)

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423 KiB

Open AccessArticle

Synthesis and Ab Initio/DFT Studies on 2-(4-methoxyphenyl)benzo[d]thiazole

by Hakan Arslan and Öztekin Algül

Int. J. Mol. Sci. 2007, 8(8), 760-776; https://doi.org/10.3390/i8080760 - 03 Aug 2007

Cited by 48 | Viewed by 11586

Abstract

2-aminothiophenol and 4-methoxybenzaldehyde were cyclized under microwaveirridation and solvent free conditions to synthesize 2-(4-methoxyphenyl)benzo[d]thiazole.The molecular structure and vibrational frequencies of the title compound in the groundstate have been investigated with ab initio (HF) and density functional theory methods(BLYP, B3LYP, B3PW91 and mPW1PW91) implementing [...] Read more.

2-aminothiophenol and 4-methoxybenzaldehyde were cyclized under microwaveirridation and solvent free conditions to synthesize 2-(4-methoxyphenyl)benzo[d]thiazole.The molecular structure and vibrational frequencies of the title compound in the groundstate have been investigated with ab initio (HF) and density functional theory methods(BLYP, B3LYP, B3PW91 and mPW1PW91) implementing the standard 6-311G(d,p) basisset. Comparison of the observed fundamental vibrational frequencies of title compound andcalculated results by HF and DFT methods indicate that B3LYP is superior to the scaledHF approach for molecular problems. Full article

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

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292 KiB

Open AccessArticle

Hydroformylation of Cyclohexene with Carbon Dioxide and Hydrogen Using Ruthenium Carbonyl Catalyst: Influence of Pressures of Gaseous Components

by Shin-ichiro Fujita, Shuhei Okamura, Yoshinari Akiyama and Masahiko Arai

Int. J. Mol. Sci. 2007, 8(8), 749-759; https://doi.org/10.3390/i8080749 - 02 Aug 2007

Cited by 30 | Viewed by 9663

Abstract

Hydroformylation of cyclohexene was studied with a catalyst system ofRu₃(CO)₁₂ and LiCl using H₂ and CO₂ instead of CO in NMP. The influence of H₂ andCO₂ pressures on the total conversion and the product distribution was [...] Read more.

Hydroformylation of cyclohexene was studied with a catalyst system ofRu₃(CO)₁₂ and LiCl using H₂ and CO₂ instead of CO in NMP. The influence of H₂ andCO₂ pressures on the total conversion and the product distribution was examined. It wasshown that increasing total pressure of H₂ and CO₂ promoted the reverse water gas shiftreaction and increased the yield of cyclohexanecarboxaldehyde. Its hydrogenation tocyclohexanemethanol was promoted with increasing H₂ pressure but suppressed withincreasing CO₂ pressure. Cyclohexane was also formed along with those products and thisdirect hydrogenation was suppressed with increasing CO₂ pressure. The roles of CO₂ as apromoter as well as a reactant were further examined by phase behavior observations andhigh pressure FTIR measurements. Full article

(This article belongs to the Section Green Chemistry)

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2913 KiB

Open AccessArticle

Salting-out in Aqueous Solutions of Ionic Liquids and K₃PO₄: Aqueous Biphasic Systems and Salt Precipitation

by Vesna Najdanovic-Visak, José N. Canongia Lopes, Zoran P. Visak, J. Trindade and Luís P. N. Rebelo

Int. J. Mol. Sci. 2007, 8(8), 736-748; https://doi.org/10.3390/i8080736 - 31 Jul 2007

Cited by 80 | Viewed by 12270

Abstract

The salting-out effect produced by the addition of potassium phosphate, K₃PO₄to aqueous solutions of water-miscible ionic liquids, viz. 1-ethyl-3-methylimidazoliumethyl sulfate, 1-butyl-3-methylimidazolium methyl sulfate, or 1-alkyl-3-methylimidazolium chloride (alkyl = butyl, octyl or decyl) is investigated. The effects areanalyzed using both [...] Read more.

The salting-out effect produced by the addition of potassium phosphate, K₃PO₄to aqueous solutions of water-miscible ionic liquids, viz. 1-ethyl-3-methylimidazoliumethyl sulfate, 1-butyl-3-methylimidazolium methyl sulfate, or 1-alkyl-3-methylimidazolium chloride (alkyl = butyl, octyl or decyl) is investigated. The effects areanalyzed using both the corresponding temperature–composition pseudo-binary andcomposition ternary phase diagrams. Different regions of liquid-liquid and solid-liquidphase demixing are mapped. The phase behavior is interpreted taking into account thecomplex and competing nature of the interactions between the ionic liquid, the inorganicsalt and water. In the case of solutions containing 1-octyl- or 1-decyl-3-methylimidazoliumchloride, the smaller magnitude of the salting-out effects is explained in terms of thepossibility of self-aggregation of the ionic liquid. Full article

(This article belongs to the Special Issue Ionic Liquids)

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Int. J. Mol. Sci., Volume 8, Issue 8 (August 2007) – 11 articles , Pages 736-893

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