Insights into the relations between the molecular structures and physicochemical properties of normal and waxy wheat B‐starch after repeated and continuous annealing

2021 ◽  
Author(s):  
Huishan Shen ◽  
Meijuan Xu ◽  
Chunyan Su ◽  
Bo Zhang ◽  
Xiangzhen Ge ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Molecular Structures ◽  
Continuous Annealing ◽  
Waxy Wheat

scholarly journals Pyr1,xTFSI Ionic Liquids (x = 1–8): A Computational Chemistry Study

2020 ◽  
Vol 10 (23) ◽  
pp. 8552
Author(s):  
Sergio Brutti
Keyword(s):  
Ionic Liquids ◽  
Physicochemical Properties ◽  
Density Functional ◽  
Ion Pairs ◽  
Molecular Size ◽  
Molecular Structures ◽  
Safety Standards ◽  
Oxidation Reduction ◽  
Reduction Stability ◽  
The Impact

Pyrrolidinium-based (Pyr) ionic liquids are a very wide family of molecular species. Pyrrolidinium cations are electrochemically stable in a large potential interval and their molecular size hinders their transport properties. The corresponding ionic liquids with trifluoromethyl sulphonyl imide anions are excellent solvents for lithium/sodium salts and have been demonstrated as electrolytes in aprotic batteries with enhanced safety standards. In this study, the analysis of the physicochemical properties of a homologous series of pyrrolidinium-based ionic liquids with general formula Pyr1,xTFSI (x = 1–8) have been tackled by first principles calculations based on the density functional theory. The molecular structures of isolated ions and ion pairs have been predicted by electronic structure calculations at B3LYP level of theory in vacuum or in simulated solvents. Thermodynamic properties have been calculated to evaluate the ion pairs dissociation and oxidation/reduction stability. This is the first systematic computational analysis of this series of molecules with a specific focus on the impact of the length of the alkyl chain on the pyrrolidinium cation on the overall physicochemical properties of the ion pairs.

Structural effects on epimerization of bacteriochlorophyll a and chlorophyll a revealed using 3-acetyl chlorophyll a

2020 ◽  
Vol 24 (04) ◽  
pp. 499-504 ◽  
Author(s):  
Yoshitaka Saga ◽  
Shiori Nakagawa
Keyword(s):  
Physicochemical Properties ◽  
Chlorophyll A ◽  
Photosynthetic Reaction Center ◽  
Molecular Structures ◽  
Structural Factors ◽  
Structural Effects ◽  
Photosynthetic Organisms ◽  
Acetyl Group ◽  
Kinetics Of

Chlorophyll (Chl) and bacteriochlorophyll (BChl) pigments, which are crucial cyclic tetrapyrroles in photosynthesis, generally have a chiral center in their exo-cyclic five-membered E-ring. Although [Formula: see text]-epimers (primed-type) of (B)Chl pigments are rarely present in photosynthetic organisms, they play key roles in photosynthetic reaction center complexes. The epimerization mechanism of (B)Chl pigments in vivo has not been unraveled. The structural effects on the physicochemical properties of (B)Chl epimerization reactions provide useful information to tackle this question. We analyzed epimerization of three pigments, BChl [Formula: see text], Chl [Formula: see text], and 3-acetyl Chl [Formula: see text], to elucidate the structural factors that are responsible for epimerization reactions. We compared the epimerization kinetics of the three pigments and concluded that the bacteriochlorin skeleton (7,8,17,18-tetrahydroporphyrin) significantly retarded the epimerization kinetics. Thus, BChl [Formula: see text] exhibited slower epimerization kinetics than Chl [Formula: see text] in spite of the presence of the electron-withdrawing 3-acetyl group that accelerates epimerization. In contrast to the large structural effects of (B)Chl molecules on epimerization kinetics, the thermodynamic properties at equilibrium in the epimerization of the three pigments were barely influenced by their molecular structures. This study also demonstrates that a semi-synthetic pigment, 3-acetyl Chl [Formula: see text], is appropriate for comparative analyses of the structural effects of BChl [Formula: see text] and Chl [Formula: see text] on their physicochemical properties.

Morphological features and physicochemical properties of waxy wheat starch

2013 ◽  
Vol 62 ◽  
pp. 304-309 ◽  
Author(s):  
Huanxin Zhang ◽  
Wei Zhang ◽  
Chunzhong Xu ◽  
Xing Zhou
Keyword(s):  
Physicochemical Properties ◽  
Morphological Features ◽  
Wheat Starch ◽  
Waxy Wheat

Physicochemical Properties and Molecular Structures of Starches from Millet (Pennisetum typhoides) and Sorghum (Sorghum bicolorL. Moench) Cultivars in Nigeria

2004 ◽  
Vol 81 (2) ◽  
pp. 255-260 ◽  
Author(s):  
Terna Gaffa ◽  
Yasushi Yoshimoto ◽  
Isao Hanashiro ◽  
Osamu Honda ◽  
Sadamichi Kawasaki ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Molecular Structures ◽  
Pennisetum Typhoides

scholarly journals Ionic Liquids as High-Performance Lubricants and Lubricant Additives

2021 ◽  
Author(s):  
Hong Guo ◽  
Patricia Iglesias Victoria
Keyword(s):  
Ionic Liquids ◽  
Physicochemical Properties ◽  
High Performance ◽  
Negative Impact ◽  
Molecular Structures ◽  
Lubricant Additives ◽  
Friction Reduction ◽  
Protic Ionic Liquids ◽  
Protection Mechanisms ◽  
Low Toxicity

Taking into account the environmental awareness and ever-growing restrictive regulations over contamination, the study of new lubricants or lubricant additives with high performance and low toxicity over the traditional lubes to reduce the negative impact on the environment is needed. In this chapter, the current literature on the use of ionic liquids, particularly protic ionic liquids, as high-performance lubricants and lubricant additives to different types of base lubricants are reviewed and described. The relation between ionic liquids structures and their physicochemical properties, such as viscosity, thermal stability, corrosion behavior, biodegradability, and toxicity, is elaborated. Friction reduction and wear protection mechanisms of the ionic liquids are discussed with relation to their molecular structures and physicochemical properties.

Comparative Studies between Physicochemical Properties of White Waxy Wheat Flour and Glutinous Rice Flour

OALib ◽  
2015 ◽  
Vol 02 (06) ◽  
pp. 1-8
Author(s):  
Yanran Qi ◽  
Tingting Cui ◽  
Yuexin Jing ◽  
Changsong Shan ◽  
Zitong Zhao ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Wheat Flour ◽  
Comparative Studies ◽  
Rice Flour ◽  
Waxy Wheat ◽  
Glutinous Rice

Comparison of Endosperm Starch Granule Development and Physicochemical Properties of Starches from Waxy and Non-Waxy Wheat

2015 ◽  
Vol 18 (11) ◽  
pp. 2409-2421 ◽  
Author(s):  
Xurun Yu ◽  
Heng Yu ◽  
Jing Zhang ◽  
Shanshan Shao ◽  
Liang Zhou ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Starch Granule ◽  
Waxy Wheat ◽  
Endosperm Starch

scholarly journals Effect of high hydrostatic pressure and retrogradation treatments on structural and physicochemical properties of waxy wheat starch

2017 ◽  
Vol 232 ◽  
pp. 560-565 ◽  
Author(s):  
Xiao-Pei Hu ◽  
Bao Zhang ◽  
Zheng-Yu Jin ◽  
Xue-Ming Xu ◽  
Han-Qing Chen
Keyword(s):  
Hydrostatic Pressure ◽  
Physicochemical Properties ◽  
High Hydrostatic Pressure ◽  
Wheat Starch ◽  
Waxy Wheat

scholarly journals Zagreb-Type Indices of R-Vertex Join and R-Edge Join of Graphs

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Jianxin Wei ◽  
Muhammad Imran ◽  
Muhamamd Azhar Iqbal ◽  
Muhammad Asad Zaighum
Keyword(s):  
Physicochemical Properties ◽  
Molecular Descriptors ◽  
Molecular Structures ◽  
Connectivity Index ◽  
Chemical Databases ◽  
Randic Index ◽  
Zagreb Indices ◽  
Mathematical Chemistry ◽  
Join Of Graphs ◽  
Arbitrary Graphs

There are various methods available which are used to search large chemical databases and to predict the physicochemical properties of molecular structures. Using molecular descriptors for this purpose is the simplest of these methods. The Zagreb indices are amongst the oldest molecular descriptors, and their properties have been extensively studied and applied in QSAR/QSPR studies. The Zagreb coindices were recently introduced, attracting the attention of researchers in mathematical chemistry. In this paper, we study Zagreb indices and several other Zagreb-type indices including the general Randić index, sum-connectivity index, F-index, and Zagreb coindices of R-vertex and edge join of two arbitrary graphs.

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