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Int. J. Mol. Sci., Volume 11, Issue 8 (August 2010) – 18 articles , Pages 2780-3038

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169 KiB  
Communication
Sixteen Polymorphic Simple Sequence Repeat Markers from Expressed Sequence Tags of the Chinese Mitten Crab Eriocheir sinensis
by Xiang-Gang Gao, Hong-Jun Li, Yun-Feng Li, Li-Jun Sui, Bao Zhu, Yu Liang, Wei-Dong Liu and Chong-Bo He
Int. J. Mol. Sci. 2010, 11(8), 3035-3038; https://doi.org/10.3390/ijms11083035 - 24 Aug 2010
Cited by 6 | Viewed by 9321
Abstract
The Chinese mitten crab (Eriocheir sinensis) is an economically important aquaculture species in China. In this study, we developed and evaluated simple sequence repeat markers from expressed sequence tags of E. sinensis. Among the 40 wild E. sinensis individuals tested, [...] Read more.
The Chinese mitten crab (Eriocheir sinensis) is an economically important aquaculture species in China. In this study, we developed and evaluated simple sequence repeat markers from expressed sequence tags of E. sinensis. Among the 40 wild E. sinensis individuals tested, 16 loci were polymorphic. The number of alleles per locus ranged from two to ten. The observed heterozygosity ranged from 0.0667 to 0.9667, whereas the expected heterozygosity ranged from 0.0661 to 0.9051. These markers have the potential for use in genetic studies of population structure and intraspecific variation in E. sinensis. Full article
(This article belongs to the Section Biochemistry)
180 KiB  
Review
Advances and Challenges in Protein-Ligand Docking
by Sheng-You Huang and Xiaoqin Zou
Int. J. Mol. Sci. 2010, 11(8), 3016-3034; https://doi.org/10.3390/ijms11083016 - 18 Aug 2010
Cited by 398 | Viewed by 23597
Abstract
Molecular docking is a widely-used computational tool for the study of molecular recognition, which aims to predict the binding mode and binding affinity of a complex formed by two or more constituent molecules with known structures. An important type of molecular docking is [...] Read more.
Molecular docking is a widely-used computational tool for the study of molecular recognition, which aims to predict the binding mode and binding affinity of a complex formed by two or more constituent molecules with known structures. An important type of molecular docking is protein-ligand docking because of its therapeutic applications in modern structure-based drug design. Here, we review the recent advances of protein flexibility, ligand sampling, and scoring functions—the three important aspects in protein-ligand docking. Challenges and possible future directions are discussed in the Conclusion. Full article
(This article belongs to the Special Issue Advances in Molecular Recognition)
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373 KiB  
Article
Impact of the Soak and the Malt on the Physicochemical Properties of the Sorghum Starches
by Irakoze Pierre Claver, Haihua Zhang, Qin Li, Kexue Zhu and Huiming Zhou
Int. J. Mol. Sci. 2010, 11(8), 3002-3015; https://doi.org/10.3390/ijms11083002 - 16 Aug 2010
Cited by 57 | Viewed by 11257
Abstract
Starches were isolated from soaked and malted sorghum and studied to understand their physicochemical and functional properties. The swelling power (SP) and the water solubility index (WSI) of both starches were nearly similar at temperatures below 50 °C, but at more than 50 [...] Read more.
Starches were isolated from soaked and malted sorghum and studied to understand their physicochemical and functional properties. The swelling power (SP) and the water solubility index (WSI) of both starches were nearly similar at temperatures below 50 °C, but at more than 50 °C, the starch isolated from malted sorghum showed lower SP and high WSI than those isolated from raw and soaked sorghum. The pasting properties of starches determined by rapid visco-analyzer (RVA) showed that malted sorghum starch had a lower viscosity peak value (86 BU/RVU) than raw sorghum starch (454 BU/RVU). For both sorghum, X-ray diffractograms exhibited an A-type diffraction pattern, typical of cereal starches and the relative degrees of crystallinity ranged from 9.62 to 15.50%. Differential scanning calorimetry (DSC) revealed that raw sorghum starch showed an endotherm with a peak temperature (Tp) at 78.06 °C and gelatinization enthalpies of 2.83 J/g whereas five-day malted sorghum starch had a Tp at 47.22 °C and gelatinization enthalpies of 2.06 J/g. Storage modulus (G′) and loss modulus (G″) of all starch suspensions increased steeply to a maximum at 70 °C and then decreased with continuous heating. The structural analysis of malted sorghum starch showed porosity on the granule’s surface susceptible to the amylolysis. The results showed that physicochemical and functional properties of sorghum starches are influenced by soaking and malting methods. Full article
(This article belongs to the Section Physical Chemistry, Theoretical and Computational Chemistry)
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511 KiB  
Article
Molecular Characteristics of Kraft-AQ Pulping Lignin Fractionated by Sequential Organic Solvent Extraction
by Kun Wang, Feng Xu and Runcang Sun
Int. J. Mol. Sci. 2010, 11(8), 2988-3001; https://doi.org/10.3390/ijms11082988 - 16 Aug 2010
Cited by 106 | Viewed by 12290
Abstract
Kraft-AQ pulping lignin was sequentially fractionated by organic solvent extractions and the molecular properties of each fraction were characterized by chemical degradation, GPC, UV, FT-IR, 13C-NMR and thermal analysis. The average molecular weight and polydispersity of each lignin fraction increased with its [...] Read more.
Kraft-AQ pulping lignin was sequentially fractionated by organic solvent extractions and the molecular properties of each fraction were characterized by chemical degradation, GPC, UV, FT-IR, 13C-NMR and thermal analysis. The average molecular weight and polydispersity of each lignin fraction increased with its hydrogen-bonding capacity (Hildebrand solubility parameter). In addition, the ratio of the non-condensed guaiacyl/syringyl units and the content of β-O-4 linkages increased with the increment of the lignin fractions extracted successively with hexane, diethylether, methylene chloride, methanol, and dioxane. Furthermore, the presence of the condensation reaction products was contributed to the higher thermal stability of the larger molecules. Full article
(This article belongs to the Section Green Chemistry)
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170 KiB  
Article
Temperature Shifts for Extraction and Purification of Zygomycetes Chitosan with Dilute Sulfuric Acid
by Akram Zamani, Lars Edebo, Claes Niklasson and Mohammad J. Taherzadeh
Int. J. Mol. Sci. 2010, 11(8), 2976-2987; https://doi.org/10.3390/ijms11082976 - 13 Aug 2010
Cited by 30 | Viewed by 10644
Abstract
The temperature-dependent hydrolysis and solubility of chitosan in sulfuric acid solutions offer the possibility for chitosan extraction from zygomycetes mycelia and separation from other cellular ingredients with high purity and high recovery. In this study, Rhizomucor pusillus biomass was initially extracted with 0.5 [...] Read more.
The temperature-dependent hydrolysis and solubility of chitosan in sulfuric acid solutions offer the possibility for chitosan extraction from zygomycetes mycelia and separation from other cellular ingredients with high purity and high recovery. In this study, Rhizomucor pusillus biomass was initially extracted with 0.5 M NaOH at 120 °C for 20 min, leaving an alkali insoluble material (AIM) rich in chitosan. Then, the AIM was subjected to two steps treatment with 72 mM sulfuric acid at (i) room temperature for 10 min followed by (ii) 120 °C for 45 min. During the first step, phosphate of the AIM was released into the acid solution and separated from the chitosan-rich residue by centrifugation. In the second step, the residual AIM was re-suspended in fresh 72 mM sulfuric acid, heated at 120 °C and hot filtered, whereby chitosan was extracted and separated from the hot alkali and acid insoluble material (HAAIM). The chitosan was recovered from the acid solution by precipitation at lowered temperature and raised pH to 8-10. The treatment resulted in 0.34 g chitosan and 0.16 g HAAIM from each gram AIM. At the start, the AIM contained at least 17% phosphate, whereas after the purification, the corresponding phosphate content of the obtained chitosan was just 1%. The purity of this chitosan was higher than 83%. The AIM subjected directly to the treatment with hot sulfuric acid (at 120 °C for 45 min) resulted in a chitosan with a phosphate impurity of 18.5%. Full article
(This article belongs to the Special Issue Chitins)
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447 KiB  
Article
A Single Amino Acid Substitution Changes Antigenicity of ORF2-Encoded Proteins of Hepatitis E Virus
by Jiu-Hong Liang, Xing Dai, Chen Dong and Ji-Hong Meng
Int. J. Mol. Sci. 2010, 11(8), 2962-2975; https://doi.org/10.3390/ijms11082962 - 12 Aug 2010
Cited by 17 | Viewed by 7773
Abstract
Extensive genomic diversity has been observed among hepatitis E virus (HEV) strains. However, the implication of the genetic heterogeneity on HEV antigenic properties is uncertain. In this study, monoclonal antibodies (Mabs) against truncated ORF2-encoded proteins (aa452‑617, designated p166 proteins) derived from HEV strains [...] Read more.
Extensive genomic diversity has been observed among hepatitis E virus (HEV) strains. However, the implication of the genetic heterogeneity on HEV antigenic properties is uncertain. In this study, monoclonal antibodies (Mabs) against truncated ORF2-encoded proteins (aa452‑617, designated p166 proteins) derived from HEV strains of Burma (genotype 1a, p166Bur), Pakistan (1b, p166Pak) and Morocco (1c, p166Mor) were raised and used for identification of HEV antigenic diversity. Six Mabs reacted to these 3 p166 proteins as well as p166 proteins constructed from strains derived from Mexico (genotype 2), US (genotype 3) and China (genotype 4), indicating the existence of pan‑genotypic epitopes. Two Mabs, 1B5 and 6C7, reacted with p166Bur and p166Mor, but not p166Pak or p166s derived from genotypes 2, 3, and 4, indicating that these 2 Mabs recognized strain-specific HEV epitopes. Both the common and specific epitopes could not be mapped by 23 synthetic peptides spanning the p166Bur sequence, suggesting that they are confirmation‑dependent. Comparative sequence analysis showed that p166Bur and p166Mor shared an identical aa sequence along their entire lengths, whereas for p166Pak the aas occupying positions 606 and 614 are different from aas at corresponding positions of p166Bur and p166Mor. Reactivity between 1B5 and p166Bur was abrogated with mutation of p166Bur/A606V, whereas p166Pak acquired the reactivity to 1B5 with mutation of p166Pak/V606A. However, mutations of p166Bur/L614M and P166Pak/M614L did not affect the immunoreactivity. Therefore, the aa occupying position 606 plays a critical role in maintaining the antigenicity of the HEV p166 proteins. Full article
(This article belongs to the Section Biochemistry)
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501 KiB  
Article
Energetics of Glucose Metabolism: A Phenomenological Approach to Metabolic Network Modeling
by Frank Diederichs
Int. J. Mol. Sci. 2010, 11(8), 2921-2961; https://doi.org/10.3390/ijms11082921 - 12 Aug 2010
Cited by 4 | Viewed by 8535
Abstract
A new formalism to describe metabolic fluxes as well as membrane transport processes was developed. The new flux equations are comparable to other phenomenological laws. Michaelis-Menten like expressions, as well as flux equations of nonequilibrium thermodynamics, can be regarded as special cases of [...] Read more.
A new formalism to describe metabolic fluxes as well as membrane transport processes was developed. The new flux equations are comparable to other phenomenological laws. Michaelis-Menten like expressions, as well as flux equations of nonequilibrium thermodynamics, can be regarded as special cases of these new equations. For metabolic network modeling, variable conductances and driving forces are required to enable pathway control and to allow a rapid response to perturbations. When applied to oxidative phosphorylation, results of simulations show that whole oxidative phosphorylation cannot be described as a two-flux-system according to nonequilibrium thermodynamics, although all coupled reactions per se fulfill the equations of this theory. Simulations show that activation of ATP-coupled load reactions plus glucose oxidation is brought about by an increase of only two different conductances: a [Ca2+] dependent increase of cytosolic load conductances, and an increase of phosphofructokinase conductance by [AMP], which in turn becomes increased through [ADP] generation by those load reactions. In ventricular myocytes, this feedback mechanism is sufficient to increase cellular power output and O2 consumption several fold, without any appreciable impairment of energetic parameters. Glucose oxidation proceeds near maximal power output, since transformed input and output conductances are nearly equal, yielding an efficiency of about 0.5. This conductance matching is fulfilled also by glucose oxidation of β-cells. But, as a price for the metabolic mechanism of glucose recognition, β-cells have only a limited capability to increase their power output. Full article
(This article belongs to the Special Issue Quantitative Modelling in Molecular System Bioenergetics)
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314 KiB  
Article
Construction of Cardiac Tissue Rings Using a Magnetic Tissue Fabrication Technique
by Hirokazu Akiyama, Akira Ito, Masanori Sato, Yoshinori Kawabe and Masamichi Kamihira
Int. J. Mol. Sci. 2010, 11(8), 2910-2920; https://doi.org/10.3390/ijms11082910 - 10 Aug 2010
Cited by 35 | Viewed by 7973
Abstract
Here we applied a magnetic force-based tissue engineering technique to cardiac tissue fabrication. A mixture of extracellular matrix precursor and cardiomyocytes labeled with magnetic nanoparticles was added into a well containing a central polycarbonate cylinder. With the use of a magnet, the cells [...] Read more.
Here we applied a magnetic force-based tissue engineering technique to cardiac tissue fabrication. A mixture of extracellular matrix precursor and cardiomyocytes labeled with magnetic nanoparticles was added into a well containing a central polycarbonate cylinder. With the use of a magnet, the cells were attracted to the bottom of the well and allowed to form a cell layer. During cultivation, the cell layer shrank towards the cylinder, leading to the formation of a ring-shaped tissue that possessed a multilayered cell structure and contractile properties. These results indicate that magnetic tissue fabrication is a promising approach for cardiac tissue engineering. Full article
(This article belongs to the Special Issue Magnetic Nanoparticles)
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181 KiB  
Review
Hypoxic and Highly Angiogenic Non-Tumor Tissues Surrounding Hepatocellular Carcinoma: The ‘Niche’ of Endothelial Progenitor Cells
by De-Cai Yu, Jun Chen and Yi-Tao Ding
Int. J. Mol. Sci. 2010, 11(8), 2901-2909; https://doi.org/10.3390/ijms11082901 - 09 Aug 2010
Cited by 26 | Viewed by 8796
Abstract
Our previous investigations showed that mobilized endothelial progenitor cells (EPCs) are enriched in non-tumor tissues (NT) surrounding hepatocellular carcinoma (HCC), compared to in tumor tissues (TT). This particular recruitment of EPCs is worth investigating further. The mobilization, recruitment, homing, and incorporation of EPCs [...] Read more.
Our previous investigations showed that mobilized endothelial progenitor cells (EPCs) are enriched in non-tumor tissues (NT) surrounding hepatocellular carcinoma (HCC), compared to in tumor tissues (TT). This particular recruitment of EPCs is worth investigating further. The mobilization, recruitment, homing, and incorporation of EPCs into tumors require the participation of multiple factors, including angiogenic factors, adherent molecules, endothelial cells, hypoxic environment, etc. Therefore, we hypothesized that NT might be a hypoxic and highly angiogenic area, into which many more EPCs are recruited and homed. In the last three years, we evaluated the hypoxic condition, angiogenic factors and angiogenic index using frozen tissues or tissue microarrays from 105 patients who had undergone hepatectomy for HCC, and here we review our results and the studies of others. All results showed the expression of Hypoxia-inducible factor-1α was higher in NT than in TT. The expression of VEGFA, bFGF, TGF-β, MCP-1, MMP-9, TIMP-2, and endostatin in NT was significantly higher than in normal liver and TT. Meanwhile, the expression of CD105—the surface marker of activated endothelial cells—was also higher in NT than in TT at the protein and mRNA levels. These investigations showed that NT is a hypoxic and highly angiogenic area, which may be the ‘niche’ of EPCs. The particular background in HCC may be related to liver cirrhosis. Therefore, non-tumor tissues surrounding HCC may be the ‘niche’ of endothelial progenitor cells. Full article
(This article belongs to the Section Biochemistry)
405 KiB  
Review
The Yin and Yang of VEGF and PEDF: Multifaceted Neurotrophic Factors and Their Potential in the Treatment of Parkinson’s Disease
by Torsten Falk, Robert T. Gonzalez and Scott J. Sherman
Int. J. Mol. Sci. 2010, 11(8), 2875-2900; https://doi.org/10.3390/ijms11082875 - 05 Aug 2010
Cited by 43 | Viewed by 13419
Abstract
Over the last few decades, vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF) have emerged as multifaceted players in not only the pathogenesis, but potential treatment, of numerous diseases. They activate diverse intracellular signaling cascades known to have extensive crosstalk, and [...] Read more.
Over the last few decades, vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF) have emerged as multifaceted players in not only the pathogenesis, but potential treatment, of numerous diseases. They activate diverse intracellular signaling cascades known to have extensive crosstalk, and have been best studied for their effects in cardiology and cancer biology. Recent work with the two factors indicates that the activity of one growth factor is often directly related to the action of the other. Their respective neuroprotective effects, in particular, raise important questions regarding the treatment of neurodegenerative disorders, including Parkinson’s disease. Full article
(This article belongs to the Special Issue Neuroprotective Strategies (special issue))
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157 KiB  
Article
In Vitro Evaluation of the Antimicrobial Effectiveness and Moisture Binding Properties of Wound Dressings
by Pornanong Aramwit, Pornprom Muangman, Nantaporn Namviriyachote and Teerapol Srichana
Int. J. Mol. Sci. 2010, 11(8), 2864-2874; https://doi.org/10.3390/ijms11082864 - 03 Aug 2010
Cited by 52 | Viewed by 11502
Abstract
A variety of silver-coated dressings and some impregnated with other chemicals are now available in the market; however, there have been few studies analyzing their comparative efficacies as antimicrobial agents. Moreover, their properties for retaining an appropriate level of moisture that is critical [...] Read more.
A variety of silver-coated dressings and some impregnated with other chemicals are now available in the market; however, there have been few studies analyzing their comparative efficacies as antimicrobial agents. Moreover, their properties for retaining an appropriate level of moisture that is critical for effective wound healing have never been reported. Five commercially available silver-containing and chlorhexidine dressings, Urgotul SSD®, Bactigras®, Acticoat®, Askina Calgitrol Ag® and Aquacel Ag®, were tested to determine their comparative antimicrobial effectiveness in vitro against five common wound pathogens, namely methicillin-sensitive and -resistant Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. Mepitel®, a flexible polyamide net coated with soft silicone, was used as a control. The zones of inhibition and both the rapidity and the extent of killing of these pathogens were evaluated. All five antimicrobial dressings investigated exerted some bactericidal activity, particularly against E. coli. The spectrum and rapidity of action ranged widely for the different dressings. Acticoat® had a broad spectrum of action against both Gram-positive and -negative bacteria. Other dressings demonstrated a narrower range of bactericidal activities. Regarding the absorption and release of moisture, Askina Calgitrol Ag® absorbed and released the most moisture from the environment. Aquacel Ag® also exhibited good moisture absorption and moisture release, but to a lower degree. The other tested dressings absorbed or released very little moisture. Askina Calgitrol Ag® and Aquacel Ag® are good alternative dressings for treating wounds with high exudates and pus. An understanding of the characteristics of these dressings will be useful for utilizing them for specific requirements under specified conditions. Full article
(This article belongs to the Section Biochemistry)
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105 KiB  
Article
Reactivation of Human Acetylcholinesterase and Butyrylcholinesterase Inhibited by Leptophos-Oxon with Different Oxime Reactivators in Vitro
by Daniel Jun, Lucie Musilova, Miroslav Pohanka, Young-Sik Jung, Pavel Bostik and Kamil Kuca
Int. J. Mol. Sci. 2010, 11(8), 2856-2863; https://doi.org/10.3390/ijms11082856 - 03 Aug 2010
Cited by 15 | Viewed by 9531
Abstract
We have evaluated in vitro the potency of 23 oximes to reactivate human erythrocyte acetylcholinesterase (AChE) and plasma butyrylcholinesterase (BChE) inhibited by racemic leptophos-oxon (O-[4-bromo-2,5-dichlorophenyl]-O-methyl phenyl-phosphonate), a toxic metabolite of the pesticide leptophos. Compounds were assayed in concentrations of [...] Read more.
We have evaluated in vitro the potency of 23 oximes to reactivate human erythrocyte acetylcholinesterase (AChE) and plasma butyrylcholinesterase (BChE) inhibited by racemic leptophos-oxon (O-[4-bromo-2,5-dichlorophenyl]-O-methyl phenyl-phosphonate), a toxic metabolite of the pesticide leptophos. Compounds were assayed in concentrations of 10 and 100 µM. In case of leptophos-oxon inhibited AChE, the best reactivation potency was achieved with methoxime, trimedoxime, obidoxime and oxime K027. The most potent reactivators of inhibited BChE were K033, obidoxime, K117, bis-3-PA, K075, K074 and K127. The reactivation efficacy of tested oximes was lower in case of leptophos-oxon inhibited BChE. Full article
(This article belongs to the Section Biochemistry)
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329 KiB  
Article
Hazardous Effects of Curcumin on Mouse Embryonic Development through a Mitochondria-Dependent Apoptotic Signaling Pathway
by Chia-Chi Chen, Ming-Shu Hsieh, Yan-Der Hsuuw, Fu-Jen Huang and Wen-Hsiung Chan
Int. J. Mol. Sci. 2010, 11(8), 2839-2855; https://doi.org/10.3390/ijms11082839 - 02 Aug 2010
Cited by 41 | Viewed by 13713
Abstract
In this study, we examined the cytotoxic effects of curcumin, the yellow pigment of Curcuma longa, on the blastocyst stage of mouse embryos, subsequent embryonic attachment, and outgrowth in vitro and in vivo implantation by embryo transfer. Mouse blastocysts were incubated in [...] Read more.
In this study, we examined the cytotoxic effects of curcumin, the yellow pigment of Curcuma longa, on the blastocyst stage of mouse embryos, subsequent embryonic attachment, and outgrowth in vitro and in vivo implantation by embryo transfer. Mouse blastocysts were incubated in medium with or without curcumin (6, 12 or 24 μM) for 24 h. Cell proliferation and growth were investigated using dual differential staining, apoptosis was analyzed with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), and implantation and post-implantation development of embryos were measured by in vitro development analysis and in vivo embryo transfer, respectively. Blastocysts treated with 24 μM curcumin displayed significantly increased apoptosis and decreased total cell number. Interestingly, we observed no marked differences in the implantation success rates between curcumin-pretreated and control blastocysts during in vitro embryonic development through implantation with a fibronectin-coated culture dish. However, in vitro treatment with 24 μM curcumin was associated with decreased implantation rate and increased resorption of postimplantation embryos in mouse uterus, as well as decreased fetal weight in the embryo transfer assay. Our results collectively indicate that in vitro exposure to curcumin triggers apoptosis and retards early postimplantation development after transfer to host mice. In addition, curcumin induces apoptotic injury effects on mouse blastocysts through ROS generation, and further promotes mitochondria-dependent apoptotic signaling processes to impair sequent embryonic development. Full article
(This article belongs to the Special Issue Advances in Molecular Toxicology)
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978 KiB  
Article
Syntheses and Characterization of New Nickel Coordination Polymers with 4,4’-Dipyridylsulfide. Dynamic Rearrangements of One-Dimensional Chains Responding to External Stimuli: Temperature Variation and Guest Releases/Re-Inclusions
by Mitsuru Kondo, Hideaki Takahashi, Hirotaka Watanabe, Yusuke Shimizu, Katsunori Yamanishi, Makoto Miyazawa, Naoko Nishina, Yutaka Ishida, Hiroyuki Kawaguchi and Fumio Uchida
Int. J. Mol. Sci. 2010, 11(8), 2821-2838; https://doi.org/10.3390/ijms11082821 - 02 Aug 2010
Cited by 2 | Viewed by 7927
Abstract
Crystal structures and dynamic rearrangements of one-dimensional coordination polymers with 4,4'-dipyridylsulfide (dps) have been studied. Reaction of Ni(NO3)2·6H2O with dps in EtOH yielded [Ni(dps)2(NO3)2]·EtOH (1), which had channels filled [...] Read more.
Crystal structures and dynamic rearrangements of one-dimensional coordination polymers with 4,4'-dipyridylsulfide (dps) have been studied. Reaction of Ni(NO3)2·6H2O with dps in EtOH yielded [Ni(dps)2(NO3)2]·EtOH (1), which had channels filled with guest EtOH molecules among the four Ni(dps)2 chains. This coordination polymer reversibly transformed the channel structure responding to temperature variations. Immersion of 1 in m-xylene released guest EtOH molecules to yield a guest-free coordination polymer [Ni(dps)2(NO3)2] (2a), which was also obtained by treatment of Ni(NO3)2·6H2O with dps in MeOH. On the other hand, removal of the guest molecules from 1 upon heating at 130 °C under reduced pressure produced a guest-free coordination polymer [Ni(dps)2(NO3)2] (2b). Although the 2a and 2b guest-free coordination polymers have the same formula, they showed differences in the assembled structures of the one-dimensional chains. Exposure of 2b to EtOH vapor reproduced 1, while 2a did not convert to 1 in a similar reaction. Reaction of Ni(NO3)2·6H2O with dps in acetone provided [Ni(dps)(NO3)2(H2O)]·Me2CO (4) with no channel structure. When MeOH or acetone was used as a reaction solvent, the [Ni(dps)2(NO3)2]·(guest molecule) type coordination polymer ,which was observed in 1, was not formed. Nevertheless, the reaction of Ni(NO3)2·6H2O with dps in MeOH/acetone mixed solution produced [Ni(dps)2(NO3)2]·0.5(MeOH·acetone) (5), which has an isostructural Ni-dps framework to 1. Full article
(This article belongs to the Special Issue Metal Organic Frameworks)
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368 KiB  
Article
Integral Kinetic Model for Studying Quercetin Degradation and Oxidation as Affected by Cholesterol During Heating
by John-Tung Chien, Da-Jung Hsu, Baskaran Stephen Inbaraj and Bing-Huei Chen
Int. J. Mol. Sci. 2010, 11(8), 2805-2820; https://doi.org/10.3390/ijms11082805 - 29 Jul 2010
Cited by 6 | Viewed by 8904
Abstract
The degradation and oxidation of quercetin, as affected by cholesterol during heating at 150 °C, was kinetically studied using non-linear regression models. Both TLC and HPLC were used to monitor the changes of quercetin, cholesterol and cholesterol oxidation products (COPs) during heating. The [...] Read more.
The degradation and oxidation of quercetin, as affected by cholesterol during heating at 150 °C, was kinetically studied using non-linear regression models. Both TLC and HPLC were used to monitor the changes of quercetin, cholesterol and cholesterol oxidation products (COPs) during heating. The formation of COPs, including triol, 7-keto, 7a-OH and 7b-OH, was completely inhibited during the initial 30 minute heating period in the presence of 0.02% quercetin, accompanied by reduction in cholesterol peroxidation and degradation. However, the quercetin degradation or oxidation proceeded fast, with the rate constants (h-1) in the presence of nitrogen, oxygen and the combination of oxygen and cholesterol being 0.253, 0.868 and 7.17, respectively. When cholesterol and quercetin were heated together, the rate constants (h-1) of cholesterol peroxidation, epoxidation and degradation were 1.8 ´ 10-4, 0.016 and 0.19, respectively. The correlation coefficients (r2) for all the oxidative and degradation reactions ranged from 0.82-0.99. The kinetic models developed in this study may be used to predict the degradation and oxidation of quercetin as affected by cholesterol during heating. Full article
(This article belongs to the Section Physical Chemistry, Theoretical and Computational Chemistry)
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361 KiB  
Article
Complexes in the Photocatalytic Reaction of CO2 and H2O: Theoretical Studies
by Dongmei Luo, Ning Zhang, Sanguo Hong, Huanwen Wu and Zhihua Liu
Int. J. Mol. Sci. 2010, 11(8), 2792-2804; https://doi.org/10.3390/ijms11082792 - 29 Jul 2010
Cited by 5 | Viewed by 9462
Abstract
: Complexes (H2O/CO2, e–(H2O/CO2) and h+–(H2O/CO2)) in the reaction system of CO2 photoreduction with H2O were researched by B3LYP and MP2 methods along with natural bond [...] Read more.
: Complexes (H2O/CO2, e–(H2O/CO2) and h+–(H2O/CO2)) in the reaction system of CO2 photoreduction with H2O were researched by B3LYP and MP2 methods along with natural bond orbital (NBO) analysis. Geometries of these complexes were optimized and frequencies analysis performed. H2O/CO2 captured photo-induced electron and hole produced e–(H2O/CO2) and h+–(H2O/CO2), respectively. The results revealed that CO2 and H2O molecules could be activated by the photo-induced electrons and holes, and each of these complexes possessed two isomers. Due to the effect of photo-induced electrons, the bond length of C=O and H-O were lengthened, while H-O bonds were shortened, influenced by holes. The infrared (IR) adsorption frequencies of these complexes were different from that of CO2 and H2O, which might be attributed to the synergistic effect and which could not be captured experimentally. Full article
(This article belongs to the Section Physical Chemistry, Theoretical and Computational Chemistry)
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17 KiB  
Correction
Correction: Patil, A. et al. Hub Promiscuity in Protein-Protein Interaction Networks. Int. J. Mol. Sci. 2010, 11, 1930-1943
by Ashwini Patil, Kengo Kinoshita and Haruki Nakamura
Int. J. Mol. Sci. 2010, 11(8), 2791; https://doi.org/10.3390/ijms11082791 - 27 Jul 2010
Cited by 39 | Viewed by 6904
Abstract
We would like to change reference 56 on page 1942 of the article [1] from: [...] Full article
173 KiB  
Article
The Effect of a Brief Salivary α-Amylase Exposure During Chewing on Subsequent in Vitro Starch Digestion Curve Profiles
by James W. Woolnough, Anthony R. Bird, John A. Monro and Charles S. Brennan
Int. J. Mol. Sci. 2010, 11(8), 2780-2790; https://doi.org/10.3390/ijms11082780 - 26 Jul 2010
Cited by 76 | Viewed by 13657
Abstract
There is inconsistency between current in vitro digestion methods with regard to accommodation of a (salivary) α-amylase exposure during the oral phase. The effect of a salivary α-amylase pre-exposure on subsequent in vitro starch digestion curve profiles for various foods was investigated. Foods [...] Read more.
There is inconsistency between current in vitro digestion methods with regard to accommodation of a (salivary) α-amylase exposure during the oral phase. The effect of a salivary α-amylase pre-exposure on subsequent in vitro starch digestion curve profiles for various foods was investigated. Foods were chewed, expectorated and the boluses left to rest for 0–15 min. During pancreatic digestion, aliquots were taken and hydrolysis curves constructed for comparison against those of the same foods comminuted with a manually-operated chopper, hence spared exposure to saliva. Hydrolysate aliquots taken at T0 (time zero) of the digestion of chewed samples contained higher levels of glucose and dextrins compared with chopped samples. Pancreatin activity immediately overwhelmed differences in sugar released due to salivary amylase activity. Within 10 min no differences were detectable between hydrolysis curves for chewed and chopped foods. Salivary amylase pretreatment does not contribute to the robustness or relative accuracy of in vitro methods. Full article
(This article belongs to the Section Biochemistry)
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