scholarly journals Screening of hydrogen bond acceptor for the synthesis of low transition temperature mixtures with malic acid

Author(s):  
C. L. Yiin ◽  
S. Yusup ◽  
A. T. Quitain ◽  
Y. Uemura
2021 ◽  
Vol 1195 (1) ◽  
pp. 012006
Author(s):  
N R Yusuf ◽  
S Yusup ◽  
C L Yiin ◽  
P J Ratri ◽  
A A Halim ◽  
...  

Abstract The concept of sustainable and green solvent has always highlighted in the field of energy and environmental science. The synthesis and application of natural-based Low Transition Temperature Mixture (LTTM) as a novel and green solvent for the lignocellulose biomass pre-treatment such as delignification of Oil-Palm Empty Fruit Bunch (EFB) have been greatly emphasized. In this present work, the investigation of LTTM efficiency as green solvent in delignification process was conducted using both theoretical and experimental studies. Initially, screening of solvation properties of different types of hydrogen bond acceptor (HBA) and predicted hydrogen bond donor (HBD) for synthesis of LTTMs was conducted using conductor-like screening model (COSMO-RS) software and formation of hydrogen bonding was evidenced using NMR spectroscopy analysis. Three types of HBA namely sucrose, choline chloride and monosodium glutamate were mixed with malic acids as HBD and their charge density distribution on the surface was determined through sigma profile (σ). The COSMO-RS results determined the σ profile of pure component malic acid to be 11.42, sucrose to be 25.37 and the total value of σ profile for mixtures is 14.19 as the best combination of LTTM composition compared to LTTM from choline chloride and monosodium glutamate (MSG). The reliability of the COSMO-RS predictions data was correlated with Nuclear Magnetic Resonance (NMR) analysis through determination of peaks with chemical shifts hydrogen bonding that suggested existence of potential interaction between malic acids and sucrose has occurred.


Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1946
Author(s):  
Nitin Chitranshi ◽  
Ashutosh Kumar ◽  
Samran Sheriff ◽  
Veer Gupta ◽  
Angela Godinez ◽  
...  

Amyloid precursor protein (APP), upon proteolytic degradation, forms aggregates of amyloid β (Aβ) and plaques in the brain, which are pathological hallmarks of Alzheimer’s disease (AD). Cathepsin B is a cysteine protease enzyme that catalyzes the proteolytic degradation of APP in the brain. Thus, cathepsin B inhibition is a crucial therapeutic aspect for the discovery of new anti-Alzheimer’s drugs. In this study, we have employed mixed-feature ligand-based virtual screening (LBVS) by integrating pharmacophore mapping, docking, and molecular dynamics to detect small, potent molecules that act as cathepsin B inhibitors. The LBVS model was generated by using hydrophobic (HY), hydrogen bond acceptor (HBA), and hydrogen bond donor (HBD) features, using a dataset of 24 known cathepsin B inhibitors of both natural and synthetic origins. A validated eight-feature pharmacophore hypothesis (Hypo III) was utilized to screen the Maybridge chemical database. The docking score, MM-PBSA, and MM-GBSA methodology was applied to prioritize the lead compounds as virtual screening hits. These compounds share a common amide scaffold, and showed important interactions with Gln23, Cys29, His110, His111, Glu122, His199, and Trp221. The identified inhibitors were further evaluated for cathepsin-B-inhibitory activity. Our study suggests that pyridine, acetamide, and benzohydrazide compounds could be used as a starting point for the development of novel therapeutics.


1998 ◽  
Vol 279 (5) ◽  
pp. 1123-1136 ◽  
Author(s):  
Ben Luisi ◽  
Modesto Orozco ◽  
Jiri Sponer ◽  
Francisco J Luque ◽  
Zippora Shakked

2006 ◽  
Vol 62 (5) ◽  
pp. o1754-o1755
Author(s):  
Neng-Fang She ◽  
Sheng-Li Hu ◽  
Hui-Zhen Guo ◽  
An-Xin Wu

The title compound, C24H18Br2N4O2·H2O, forms a supramolecular structure via N—H...O, O—H...O and C—H...O hydrogen bonds. In the crystal structure, the water molecule serves as a bifurcated hydrogen-bond acceptor and as a hydrogen-bond donor.


2014 ◽  
Vol 119 (1) ◽  
pp. 365-372 ◽  
Author(s):  
Joshua Abelard ◽  
Amanda R. Wilmsmeyer ◽  
Angela C. Edwards ◽  
Wesley O. Gordon ◽  
Erin M. Durke ◽  
...  

2012 ◽  
Vol 68 (6) ◽  
pp. m834-m834 ◽  
Author(s):  
Kwang Ha

The PtII ion in the title complex, [PtI2(C14H10N4)], exists in a distorted square-planar environment defined by the two pyridine N atoms of the chelating 2,3-di-2-pyridylpyrazine ligand and two iodide anions. The pyridine rings are inclined to the least-squares plane of the PtI2N2 unit [maximum deviation = 0.070 (3) Å] at 66.1 (2) and 65.9 (2)°; the pyrazine ring is perpendicular to this plane [dihedral angle = 89.7 (2)°]. Two intermolecular C—H...I hydrogen bonds, both involving the same I atom as hydrogen-bond acceptor, generate a layer structure extending parallel to (001). Molecules are stacked in columns along the a axis. Along the b axis, successive molecules stack in opposite directions.


2018 ◽  
Vol 38 (4) ◽  
pp. 1800115 ◽  
Author(s):  
Christoph A. Bauer ◽  
Gisbert Schneider ◽  
Andreas H. Göller

2017 ◽  
Vol 46 (15) ◽  
pp. 4960-4967 ◽  
Author(s):  
Ferdinand Groenewald ◽  
Helgard G. Raubenheimer ◽  
Jan Dillen ◽  
Catharine Esterhuysen

MP2/aug-cc-pVTZ-pp calculations show that the Au(i) atom of dimethylaurate behaves as a hydrogen-bond acceptor to a range of hydrogen-bond donors.


2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Christoph A. Bauer ◽  
Gisbert Schneider ◽  
Andreas H. Göller

Abstract We present machine learning (ML) models for hydrogen bond acceptor (HBA) and hydrogen bond donor (HBD) strengths. Quantum chemical (QC) free energies in solution for 1:1 hydrogen-bonded complex formation to the reference molecules 4-fluorophenol and acetone serve as our target values. Our acceptor and donor databases are the largest on record with 4426 and 1036 data points, respectively. After scanning over radial atomic descriptors and ML methods, our final trained HBA and HBD ML models achieve RMSEs of 3.8 kJ mol−1 (acceptors), and 2.3 kJ mol−1 (donors) on experimental test sets, respectively. This performance is comparable with previous models that are trained on experimental hydrogen bonding free energies, indicating that molecular QC data can serve as substitute for experiment. The potential ramifications thereof could lead to a full replacement of wetlab chemistry for HBA/HBD strength determination by QC. As a possible chemical application of our ML models, we highlight our predicted HBA and HBD strengths as possible descriptors in two case studies on trends in intramolecular hydrogen bonding.


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