Novel clioquinol and its analogous platinum complexes: importance, role of the halogen substitution and the hydroxyl group of the ligand

2013 ◽  
Vol 42 (37) ◽  
pp. 13343 ◽  
Author(s):  
Cecilia Martín Santos ◽  
Silvia Cabrera ◽  
Carla Ríos-Luci ◽  
José M. Padrón ◽  
Isabel López Solera ◽  
...  
Keyword(s):  
Platinum Complexes ◽  
Hydroxyl Group

Insights into the Role of Hydroxyl Group on Carboxyl-modified MWCNTs in Accelerating Atenolol Removal by Fe(III)/H2O2 System

2021 ◽  
pp. 130581
Author(s):  
Shuai Shao ◽  
Gaobo Wang ◽  
Zhimin Gong ◽  
Mengjie Wang ◽  
Jianhua Hu ◽  
...  
Keyword(s):  
Hydroxyl Group ◽  
H2o2 System

The Role of Hydroxyl Group Acidity on the Activity of Silica-Supported Secondary Amines for the Self-Condensation ofn-Butanal

ChemSusChem ◽  
2014 ◽  
Vol 8 (3) ◽  
pp. 466-472 ◽  
Author(s):  
Sankaranarayanapillai Shylesh ◽  
David Hanna ◽  
Joseph Gomes ◽  
Christian G. Canlas ◽  
Martin Head-Gordon ◽  
...  
Keyword(s):  
The Self ◽  
Secondary Amines ◽  
Hydroxyl Group

Stability of Methyl Platinum Complexes in Water:  The Role of pH and Geometry

2003 ◽  
Vol 22 (4) ◽  
pp. 826-833 ◽  
Author(s):  
Derrick W. Lucey ◽  
Derrik S. Helfer ◽  
Jim D. Atwood
Keyword(s):  
Platinum Complexes

scholarly journals Functional role of residues involved in substrate binding of human 4-hydroxyphenylpyruvate dioxygenase

2021 ◽  
Author(s):  
Chih-Wei Huang ◽  
Chi-Ching Hwang ◽  
Yung-Lung Chang ◽  
Jen-Tzu Liu ◽  
Sheng-Peng Wu ◽  
...  
Keyword(s):  
Binding Affinity ◽  
Functional Role ◽  
Substrate Binding ◽  
Critical Role ◽  
Intermediate Formation ◽  
Hydroxyl Group ◽  
Double Mutation ◽  
Closed Conformation ◽  
Bond Network

4-Hydroxylphenylpyruvate dioxygenase (HPPD) catalyzes the conversion of 4-hydroxylphenylpyruvate (HPP) to homogentisate, the important step for tyrosine catabolism. Comparison of the structure of human HPPD with the substrate-bound structure of A. thaliana HPPD revealed notably different orientations of the C-terminal helix. This helix performed as a closed conformation in human enzyme. Simulation revealed a different substrate-binding mode in which the carboxyl group of HPP interacted by a H-bond network formed by Gln334, Glu349 (the metal-binding ligand), and Asn363 (in the C-terminal helix). The 4-hydroxyl group of HPP interacted with Gln251 and Gln265. The relative activity and substrate-binding affinity were preserved for the Q334A mutant, implying the alternative role of Asn363 for HPP binding and catalysis. The reduction in kcat/Km of the Asn363 mutants confirmed the critical role in catalysis. Compared to the N363A mutant, the dramatic reduction in the Kd and thermal stability of the N363D mutant implies the side-chain effect in the hinge region rotation of the C-terminal helix. The activity and binding affinity were not recovered by double mutation; however, the 4-hydroxyphenylacetate intermediate formation by the uncoupled reaction of Q334N/N363Q and Q334A/N363D mutants indicated the importance of the H-bond network in the electrophilic reaction. These results highlight the functional role of the H-bond network in a closed conformation of the C-terminal helix to stabilize the bound substrate. The extremely low activity and reduction in Q251E’s Kd suggest that interaction coupled with the H-bond network is crucial to locate the substrate for nucleophilic reaction.

Adsorptive removal of diclofenac sodium from aqueous solution by magnetic COF: Role of hydroxyl group on COF

2020 ◽  
Vol 603 ◽  
pp. 125238 ◽  
Author(s):  
Xin Mi ◽  
Shuangxi Zhou ◽  
Ziming Zhou ◽  
Mohammadtaghi Vakili ◽  
Yue Qi ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Diclofenac Sodium ◽  
Hydroxyl Group ◽  
Adsorptive Removal

The Role of the 5'-Hydroxyl Group of Adenosine in Determining Substrate Specificity for Adenosine Deaminase

1967 ◽  
Vol 10 (5) ◽  
pp. 908-912 ◽  
Author(s):  
Alexander. Bloch ◽  
Morris J. Robins ◽  
James R. McCarthy
Keyword(s):  
Substrate Specificity ◽  
Adenosine Deaminase ◽  
Hydroxyl Group

Mass Spectrometry of N-Benzoyl-2-hydroxyalkylamines. Role of the Hydroxylic Hydrogen in the Fragmentation Pattern

1975 ◽  
Vol 53 (21) ◽  
pp. 3175-3187 ◽  
Author(s):  
Don C. DeJongh ◽  
Denis C. K. Lin ◽  
Pierre LeClair-Lanteigne ◽  
Denis Gravel
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Hydroxyl Group ◽  
Fragmentation Pattern ◽  
Relative Importance ◽  
Hydrogen Atoms ◽  
Related Compounds ◽  
Double Hydrogen ◽  
Hydrogen Rearrangement

An interesting rearrangement has been observed in the mass spectra of a series of N-benzoyl-2-hydroxyalkylamines. The hydrogen atom of the hydroxyl group is transferred to the N-benzoyl portion of the molecular ion and the bond between positions 1 and 2 in the N-alkyl group is cleaved. A rearrangement ion, observed at m/e 135, is formed along with a neutral aldehyde or ketone. When the hydroxylic hydrogen is replaced by a trimethylsilyl substituent, the latter group is transferred with comparable efficiency. Differences in the relative importance of this rearrangement in the mass spectra of a series of related compounds with decreasing substitution at position 2, have been explained by differences in the stabilities of the neutral molecules formed along with m/e 135 and by the occurrence of a double hydrogen rearrangement which competes if hydrogen atoms are present in a relationship gamma and delta to the carbonyl group.

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