Free Radical Scavenging and Antioxidant Activities of Substituted Hexahydropyridoindoles. Quantitative Structure−Activity Relationships

2006 ◽  
Vol 49 (8) ◽  
pp. 2543-2548 ◽  
Author(s):  
Lucia Rackova ◽  
Vladimir Snirc ◽  
Magdalena Majekova ◽  
Pavol Majek ◽  
Milan Stefek
Keyword(s):  
Free Radical ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Quantitative Structure ◽  
Structure Activity Relationships ◽  
Structure Activity ◽  
Quantitative Structure Activity Relationships

scholarly journals Non-Linear Quantitative Structure–Activity Relationships Modelling, Mechanistic Study and In-Silico Design of Flavonoids as Potent Antioxidants

2019 ◽  
Vol 20 (9) ◽  
pp. 2328 ◽  
Author(s):  
Petar Žuvela ◽  
Jonathan David ◽  
Xin Yang ◽  
Dejian Huang ◽  
Ming Wah Wong
Keyword(s):  
Electron Transfer ◽  
Antioxidant Activities ◽  
Qsar Model ◽  
Quantitative Structure ◽  
Structure Activity Relationships ◽  
Structure Activity ◽  
Non Linear ◽  
Quantitative Structure Activity Relationships ◽  
Mean Square Errors ◽  
Proton Loss

In this work, we developed quantitative structure–activity relationships (QSAR) models for prediction of oxygen radical absorbance capacity (ORAC) of flavonoids. Both linear (partial least squares—PLS) and non-linear models (artificial neural networks—ANNs) were built using parameters of two well-established antioxidant activity mechanisms, namely, the hydrogen atom transfer (HAT) mechanism defined with the minimum bond dissociation enthalpy, and the sequential proton-loss electron transfer (SPLET) mechanism defined with proton affinity and electron transfer enthalpy. Due to pronounced solvent effects within the ORAC assay, the hydration energy was also considered. The four-parameter PLS-QSAR model yielded relatively high root mean square errors (RMSECV = 0.783, RMSEE = 0.668, RMSEP = 0.900). Conversely, the ANN-QSAR model yielded considerably lower errors (RMSEE = 0.180 ± 0.059, RMSEP1 = 0.164 ± 0.128, and RMSEP2 = 0.151 ± 0.114) due to the inherent non-linear relationships between molecular structures of flavonoids and ORAC values. Five-fold cross-validation was found to be unsuitable for the internal validation of the ANN-QSAR model with a high RMSECV of 0.999 ± 0.253; which is due to limited sample size where resampling with replacement is a considerably better alternative. Chemical domains of applicability were defined for both models confirming their reliability and robustness. Based on the PLS coefficients and partial derivatives, both models were interpreted in terms of the HAT and SPLET mechanisms. Theoretical computations based on density functional theory at ωb97XD/6-311++G(d,p) level of theory were also carried out to further shed light on the plausible mechanism of anti-peroxy radical activity. Calculated energetics for simplified models (genistein and quercetin) with peroxyl radical derived from 2,2′-azobis (2-amidino-propane) dihydrochloride suggested that both SPLET and single electron transfer followed by proton loss (SETPL) mechanisms are competitive and more favorable than HAT in aqueous medium. The finding is in good accord with the ANN-based QSAR modelling results. Finally, the strongly predictive ANN-QSAR model was used to predict antioxidant activities for a series of 115 flavonoids designed combinatorially with flavone as a template. Structural trends were analyzed, and general guidelines for synthesis of new flavonoid derivatives with potentially potent antioxidant activities were given.

scholarly journals Correction: Analysis of the quantitative structure–activity relationship of glutathione-derived peptides based on different free radical scavenging systems

MedChemComm ◽  
2016 ◽  
Vol 7 (11) ◽  
pp. 2193-2193
Author(s):  
Wenzhen Liao ◽  
Longjian Gu ◽  
Yamei Zheng ◽  
Zisheng Zhu ◽  
Mouming Zhao ◽  
...  
Keyword(s):  
Free Radical ◽  
Radical Scavenging ◽  
Quantitative Structure Activity Relationship ◽  
Structure Activity Relationship ◽  
Free Radical Scavenging ◽  
Activity Relationship ◽  
Quantitative Structure ◽  
Structure Activity ◽  
Relationship Of

Correction for ‘Analysis of the quantitative structure–activity relationship of glutathione-derived peptides based on different free radical scavenging systems’ by Wenzhen Liao et al., Med. Chem. Commun., 2016, DOI: 10.1039/c6md00006a.

scholarly journals Free Radical Scavenging Activity Evaluation of Hydrazones by Quantitative Structure Activity Relationship

2018 ◽  
Vol 62 (1) ◽  
Author(s):  
Ikechukwu Ogadimma Alisi ◽  
Adamu Uzairu ◽  
Stephen Eyije Abechi ◽  
Sulaiman Ola Idris
Keyword(s):  
Free Radical ◽  
Information Content ◽  
Structural Information ◽  
Radical Scavenging ◽  
Quantitative Structure Activity Relationship ◽  
Free Radical Scavenging ◽  
Activity Relationship ◽  
Quantitative Structure ◽  
Structure Activity ◽  
Content Index

The 2, 2-diphenyl-1-picrylhydrazyl (<strong>DPPH</strong>) free radical scavenging properties of selected hydrazone antioxidants was investigated by the application of Quantitative Structure Activity Relationship (<strong>QSAR</strong>). Density functional theory (<strong>DFT</strong>) was employed in the optimization of the molecular structures. Internal and external validation as well as y-randomization tests were conducted in order to confirm the statistical reliability and acceptability of the developed models. The leverage approach was employed in the assessment of the applicability domain of the developed model. While the relative contribution and strength of each descriptor in the model was obtained by estimating the variation inflation factor, mean effect, and degree of contribution of each descriptor in the developed model. Model 3 which gave the best validation results was chosen as the best of the five models. This model dictates that the most important descriptors that influence the free radical scavenging activities of  the hydrazone antioxidants are the Broto-Moreau autocorrelation - lag 2 / weighted by polarizabilities; Count of atom-type H E-State: H on C  bonded to saturated C; Number of hydrogen bond donors (using CDK H Bond Donor Count Descriptor algorithm); Structural information content index (neighborhood symmetry of 1-order) and the 3D topological distance based autocorrelation - lag 7 / weighted by I-state descriptors. The Structural information content index descriptor was observed to be the most influential of all the descriptors

Analysis of the quantitative structure–activity relationship of glutathione-derived peptides based on different free radical scavenging systems

MedChemComm ◽  
2016 ◽  
Vol 7 (11) ◽  
pp. 2083-2093 ◽  
Author(s):  
Wenzhen Liao ◽  
Longjian Gu ◽  
Yamei Zheng ◽  
Zisheng Zhu ◽  
Mouming Zhao ◽  
...  
Keyword(s):  
Free Radical ◽  
Radical Scavenging ◽  
Quantitative Structure Activity Relationship ◽  
Structure Activity Relationship ◽  
Free Radical Scavenging ◽  
Activity Relationship ◽  
Quantitative Structure ◽  
Structure Activity ◽  
Relationship Of

In the present study, eleven glutathione-derived peptides, including Glu-Cys-His, Pro-Leu-Gly, Pro-Cys-Gly, Phe-Lys-Leu, Leu-His-Gly, Lys-Leu-Glu, Lys-Val-His, Tyr-Glu-Gly, Tyr-His-Leu, Gly-Glu-Leu and Gly-Pro-Glu, were designed.

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