scholarly journals A Review of the Current Knowledge of Thermal Stability of Anthocyanins and Approaches to Their Stabilization to Heat

Antioxidants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1337
Author(s):  
Simona Oancea
Keyword(s):  
Thermal Stability ◽  
Rational Design ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Scientific Progress ◽  
Bioactive Molecules ◽  
Environmental Stability ◽  
Published Data ◽  
Thermal Stability Of ◽  
Anthocyanin Degradation

Anthocyanins are colored valuable biocompounds, of which extraction increases globally, although functional applications are restrained by their limited environmental stability. Temperature is a critical parameter of food industrial processing that impacts on the food matrix, particularly affecting heat-sensitive compounds such as anthocyanins. Due to the notable scientific progress in the field of thermal stability of anthocyanins, an analytical and synthetic integration of published data is required. This review focuses on the molecular mechanisms and the kinetic parameters of anthocyanin degradation during heating, both in extracts and real food matrices. Several kinetic models (Arrhenius, Eyring, Ball) of anthocyanin degradation were studied. Crude extracts deliver more thermally stable anthocyanins than purified ones. A different anthocyanin behavior pattern within real food products subjected to thermal processing has been observed due to interactions with some nutrients (proteins, polysaccharides). The most recent studies on the stabilization of anthocyanins by linkages to other molecules using classical and innovative methods are summarized. Ensuring appropriate thermal conditions for processing anthocyanin-rich food will allow a rational design for the future development of stable functional products, which retain these bioactive molecules and their functionalities to a great extent.

scholarly journals Engineering Improves Enzymatic Synthesis of L-Tryptophan by Tryptophan Synthase from Escherichia coli

2020 ◽  
Vol 8 (4) ◽  
pp. 519
Author(s):  
Lisheng Xu ◽  
Fangkai Han ◽  
Zeng Dong ◽  
Zhaojun Wei
Keyword(s):  
Thermal Stability ◽  
Amino Acid ◽  
Directed Evolution ◽  
Amino Acid Residue ◽  
Rational Design ◽  
Molecular Engineering ◽  
Mutant Enzyme ◽  
Tryptophan Synthase ◽  
Mutant Library ◽  
Thermal Stability Of

To improve the thermostability of tryptophan synthase, the molecular modification of tryptophan synthase was carried out by rational molecular engineering. First, B-FITTER software was used to analyze the temperature factor (B-factor) of each amino acid residue in the crystal structure of tryptophan synthase. A key amino acid residue, G395, which adversely affected the thermal stability of the enzyme, was identified, and then, a mutant library was constructed by site-specific saturation mutation. A mutant (G395S) enzyme with significantly improved thermal stability was screened from the saturated mutant library. Error-prone PCR was used to conduct a directed evolution of the mutant enzyme (G395S). Compared with the parent, the mutant enzyme (G395S /A191T) had a Km of 0.21 mM and a catalytic efficiency kcat/Km of 5.38 mM−1∙s−1, which was 4.8 times higher than that of the wild-type strain. The conditions for L-tryptophan synthesis by the mutated enzyme were a L-serine concentration of 50 mmol/L, a reaction temperature of 40 °C, pH of 8, a reaction time of 12 h, and an L-tryptophan yield of 81%. The thermal stability of the enzyme can be improved by using an appropriate rational design strategy to modify the correct site. The catalytic activity of tryptophan synthase was increased by directed evolution.

scholarly journals Polyaniline Conducting Electroactive Polymers Thermal and Environmental Stability Studies

2006 ◽  
Vol 3 (4) ◽  
pp. 202-217 ◽  
Author(s):  
Reza Ansari ◽  
M. B. Keivani
Keyword(s):  
Thermal Stability ◽  
Electrical Conductivity ◽  
Conducting Polymers ◽  
Electrochemical Techniques ◽  
Electroactive Polymers ◽  
The Other ◽  
Environmental Stability ◽  
Stability Studies ◽  
Fundamental Information ◽  
Thermal Stability Of

In the current studies, polyaniline (PANi) was prepared both chemical and electrochemically in the presence of different bronsted acids from aqueous solutions. The effect of thermal treatment on electrical conductivity, and thermal stability of the PANi conducting polymers were investigated using 4-point probe and TGA techniques respectively. It was found that polymer prepared by CV method is more thermally stable than those prepared by the other electrochemical techniques. In this paper we have also reviewed some fundamental information about synthesis, general properties, diverse applications, thermal and environmental stability of polyaniline conducting polymers.

scholarly journals Role of microRNA in muscle regeneration and diseases related to muscle dysfunction in atrophy, cachexia, osteoporosis, and osteoarthritis

2020 ◽  
Vol 9 (11) ◽  
pp. 798-807
Author(s):  
Joanna Brzeszczyńska ◽  
Filip Brzeszczyński ◽  
David F Hamilton ◽  
Robin McGregor ◽  
A. Hamish R. W. Simpson
Keyword(s):  
Cell Activation ◽  
Molecular Mechanisms ◽  
Muscle Wasting ◽  
Current Knowledge ◽  
Published Data ◽  
Proliferation And Differentiation ◽  
Improve Patient Management ◽  
Limb Immobilization ◽  
Improve Patient

MicroRNAs (miRNAs) are a class of small non-coding RNAs that have emerged as potential predictive, prognostic, and therapeutic biomarkers, relevant to many pathophysiological conditions including limb immobilization, osteoarthritis, sarcopenia, and cachexia. Impaired musculoskeletal homeostasis leads to distinct muscle atrophies. Understanding miRNA involvement in the molecular mechanisms underpinning conditions such as muscle wasting may be critical to developing new strategies to improve patient management. MicroRNAs are powerful post-transcriptional regulators of gene expression in muscle and, importantly, are also detectable in the circulation. MicroRNAs are established modulators of muscle satellite stem cell activation, proliferation, and differentiation, however, there have been limited human studies that investigate miRNAs in muscle wasting. This narrative review summarizes the current knowledge as to the role of miRNAs in the skeletal muscle differentiation and atrophy, synthesizing the findings of published data. Cite this article: Bone Joint Res 2020;9(11):798–807.

scholarly journals A Rational Design of the Sintering-Resistant Au-CeO2 Nanoparticles Catalysts for CO Oxidation: The Influence of H2 Pretreatments

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1952 ◽  
Author(s):  
Yuqi Sun ◽  
Wei Liu ◽  
Miao Tian ◽  
Liguo Wang ◽  
Zhongpeng Wang
Keyword(s):  
Thermal Stability ◽  
Co Oxidation ◽  
Noble Metal ◽  
Rational Design ◽  
Co Adsorption ◽  
Precipitation Method ◽  
Au Nps ◽  
Metal Support Interaction ◽  
H2 Pretreatment ◽  
Thermal Stability Of

The redox pretreatment of samples is one of the crucial ways of altering the catalytic properties of the supported noble metal materials in many heterogeneous reactions. Here, H2-reducing pretreatment is reported to enhance the thermal stability of Au-CeO2 catalysts prepared by the deposition–precipitation method and calcination at 600 °C for CO oxidation. In order to understand the improved activity and thermal stability, a series of techniques were used to characterize the physico-chemical changes of the catalyst samples. H2 pretreatment may lead to: (i) a strong metal–support interaction (SMSI) between Au nanoparticles (NPs) and CeO2, evidenced by the particular coverage of Au NPs by CeO2, electronic interactions and CO adsorption changes. (ii) the production of surface bicarbonates which can accelerate CO oxidation. As a result, the H2 pretreatment makes the Au NPs more resistant to sintering at high temperature and enhances the CO oxidation activity. Furthermore, this reduction pretreatment strategy may provide a potential approach to enhance the thermal-stability of other supported noble metal catalysts.

scholarly journals Epigenetic Crosstalk between the Tumor Microenvironment and Ovarian Cancer Cells: A Therapeutic Road Less Traveled

Cancers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 295 ◽  
Author(s):  
Yuliya Klymenko ◽  
Kenneth P. Nephew
Keyword(s):  
Ovarian Cancer ◽  
Tumor Microenvironment ◽  
Cancer Cells ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Abdominal Cavity ◽  
Malignant Ascites ◽  
Bioactive Molecules ◽  
Ovarian Cancer Cells ◽  
Secondary Tumor

Metastatic dissemination of epithelial ovarian cancer (EOC) predominantly occurs through direct cell shedding from the primary tumor into the intra-abdominal cavity that is filled with malignant ascitic effusions. Facilitated by the fluid flow, cells distribute throughout the cavity, broadly seed and invade through peritoneal lining, and resume secondary tumor growth in abdominal and pelvic organs. At all steps of this unique metastatic process, cancer cells exist within a multidimensional tumor microenvironment consisting of intraperitoneally residing cancer-reprogramed fibroblasts, adipose, immune, mesenchymal stem, mesothelial, and vascular cells that exert miscellaneous bioactive molecules into malignant ascites and contribute to EOC progression and metastasis via distinct molecular mechanisms and epigenetic dysregulation. This review outlines basic epigenetic mechanisms, including DNA methylation, histone modifications, chromatin remodeling, and non-coding RNA regulators, and summarizes current knowledge on reciprocal interactions between each participant of the EOC cellular milieu and tumor cells in the context of aberrant epigenetic crosstalk. Promising research directions and potential therapeutic strategies that may encompass epigenetic tailoring as a component of complex EOC treatment are discussed.

scholarly journals Rational Design of Alginate Lyase from Microbulbifer sp. Q7 to Improve Thermal Stability

Marine Drugs ◽  
2019 ◽  
Vol 17 (6) ◽  
pp. 378 ◽  
Author(s):  
Min Yang ◽  
Su-Xiao Yang ◽  
Zhe-Min Liu ◽  
Nan-Nan Li ◽  
Li Li ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Disulfide Bonds ◽  
Rational Design ◽  
Spatial Configuration ◽  
Specific Activity ◽  
Alginate Lyase ◽  
Life Time ◽  
Enzyme Specific Activity ◽  
Elimination Mechanism ◽  
Thermal Stability Of

Alginate lyase degrades alginate by the β-elimination mechanism to produce oligosaccharides with special bioactivities. The low thermal stability of alginate lyase limits its industrial application. In this study, introducing the disulfide bonds while using the rational design methodology enhanced the thermal stability of alginate lyase cAlyM from Microbulbifer sp. Q7. Enzyme catalytic sites, secondary structure, spatial configuration, and molecular dynamic simulation were comprehensively analyzed. When compared with cAlyM, the mutants D102C-A300C and G103C-T113C showed an increase by 2.25 and 1.16 h, respectively, in half-life time at 45 °C, in addition to increases by 1.7 °C and 0.4 °C in the melting temperature, respectively. The enzyme-specific activity and kcat/Km values of D102C-A300C were 1.8- and 1.5-times higher than those of cAlyM, respectively. The rational design strategy that was used in this study provides a valuable method for improving the thermal stability of the alginate lyase.

Anti-aging potential of tree nuts with a focus on the phytochemical composition, molecular mechanisms and thermal stability of major bioactive compounds

2018 ◽  
Vol 9 (5) ◽  
pp. 2554-2575 ◽  
Author(s):  
Marius Emil Rusu ◽  
Ana-Maria Gheldiu ◽  
Andrei Mocan ◽  
Laurian Vlase ◽  
Daniela-Saveta Popa
Keyword(s):  
Thermal Stability ◽  
Bioactive Compounds ◽  
Functional Foods ◽  
Molecular Mechanisms ◽  
Biological Value ◽  
Tree Nuts ◽  
Phytochemical Composition ◽  
Macro And Micronutrients ◽  
Thermal Stability Of

Tree nuts, complete functional foods, contain macro- and micronutrients of high biological value.

scholarly journals Emerging Highly Virulent Porcine Epidemic Diarrhea Virus: Molecular Mechanisms of Attenuation and Rational Design of Live Attenuated Vaccines

2019 ◽  
Vol 20 (21) ◽  
pp. 5478 ◽  
Author(s):  
Yixuan Hou ◽  
Qiuhong Wang
Keyword(s):  
Porcine Epidemic Diarrhea Virus ◽  
Rational Design ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Economic Losses ◽  
Live Attenuated Vaccines ◽  
Diarrhea Virus ◽  
Porcine Epidemic Diarrhea ◽  
Highly Virulent

The highly virulent porcine epidemic diarrhea virus (PEDV) emerged in China in 2010. It infects pigs of all ages, and causes severe diarrhea and high mortality rates in newborn pigs, leading to devastating economic losses in the pork industry worldwide. Effective and safe vaccines against highly virulent PEDV strains are still unavailable, hampering the further prevention, control and eradication of the disease in herds. Vaccination of pregnant sows with live attenuated vaccines (LAVs) is the most effective strategy to induce lactogenic immunity in the sows, which provides A passive protection of suckling piglets against PEDV via the colostrum (beestings, or first milk) and milk. Several LAV candidates have been developed via serially passaging the highly virulent PEDV isolates in non-porcine Vero cells. However, their efficacies in the induction of sufficient protection against virulent PEDV challenge vary in vivo. In this review, we summarize the current knowledge of the virulence-related mutations of PEDV and their potential roles in PEDV attenuation in vivo. With the successful development of reverse genetics systems for PEDV, we also discuss how to use them to generate promising LAV candidates that are safe, effective and genetically stable. This article provides timely insight into the rational design of effective and safe PEDV LAV candidates.

The Ordered Phase Formation in Ti-Al-Ga Alloys

1970 ◽  
Vol 28 ◽  
pp. 440-441
Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Titanium Alloys ◽  
Growth Kinetics ◽  
Stoichiometric Composition ◽  
Good Potential ◽  
Alpha Titanium ◽  
Cold Rolled ◽  
Kinetics Of ◽  
Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

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