Zangeneh, Maryam (2012) Prediction of phenolic properties of some phenol derivatives by using pure quantum descriptors and applying QSAR Methods. Masters thesis, University of Zabol.
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Prediction of phenolic properties of some phenol derivatives by using pure quantum descriptors and applying QSAR Methods.pdf Download (267kB) | Preview |
Abstract
In this study attempt were done to construct a local quantitative structure activity relationships between the phenolic properties of 67 phenol derivatives and their corresponding quantum mechanical variables of charge, dipole, electrostatic potential and orbital energy. As follows, all molecular structures were produced and optimized in HyperChem and Guassian98 software on theoretical level of HF/6-31g basis function. Where the Isolated and in solvent (water and octanol) interactions, using onzagre reaction field model, were considered. Besides, carbon-13 chemical shifts for those carbon atoms only situated on the parent molecule were calculated using HF/6-31g NMR=giao keyword in Guassian98. Multivariate linear regression with correlation coefficient of R2LOO=0.43 reveals that LUMO variable show significant effect on phenolic activity (Log (1/C) of all phenol derivatives. As our preliminary studies proposes two different trend of mechanisms for data set, the modeling was extended for two 51 and 16 groups separately. Where, their corresponding linear correlation coefficient models obtained to be R2LOO=0.64 and =0.7, respectively. Although the two different models were obtained, the LUMO variable in both models shows a significant contribution. In another attempt, to bring all phenol derivatives in the same regime, an artificial neural network in conjunction with Genetic algorithm variable selection model was employed. An excellent correlation coefficient (R2=0.79) with respect to the previous one was achieved. In present model, highest positive charge, besides orbital energy governs the activity. Therefore, models propose that the phenolic activity performs through charge exchange between the phenol derivatives and target molecules. It is believed that the substituent stabilize the phenol ring through inductive and/or resonance mechanism are more favorable in increasing phenolic properties.
| Item Type: | Thesis (Masters) |
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| Uncontrolled Keywords: | Phenolic activity; QSAR; Phenol derivatives; quantum parameters |
| Subjects: | Q Science > QD Chemistry |
| Depositing User: | admin admin1 admin2 |
| Date Deposited: | 04 Dec 2016 05:57 |
| Last Modified: | 04 Dec 2016 05:57 |
| URI: | http://eprints.uoz.ac.ir/id/eprint/1059 |
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