• فهرس المقالات multiple linear regressions

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        1 - Quantitative structure–property relationship models to Predict some thermodynamic properties of Imidazole Derivatives using molecular descriptor and genetic algorithm-multiple linear regressions
        shiva Moshayedi fatemeh shafiei Tahereh Momeni Isfahani
        Imidazole is compound with a wide range of biological activities and imidazole derivatives are the basis of several groups of drugs.In this study the relationship between molecular descriptors and the thermal energy (Eth kJ/mol), and heat capacity (Cv J/mol) of imidazol أکثر
        Imidazole is compound with a wide range of biological activities and imidazole derivatives are the basis of several groups of drugs.In this study the relationship between molecular descriptors and the thermal energy (Eth kJ/mol), and heat capacity (Cv J/mol) of imidazole derivatives is studied. The chemical structures of 85 Imidazole derivatives were optimized at HF/6-311G* level with Gaussian 98 software.Molecular descriptors were calculated for selected compound by using the Dragon software.The Genetic algorithm- multiple linear regression (GA-MLR) and backward methods were used to select the suitable descriptors and also for predicting the thermodynamic properties of imidazole derivatives.The obtained models were evaluated by statistical parameters, such as correlation coefficient (R2adj), Fisher ratio (F), Root Mean Square Error (RMSE), Durbin-Watson statistic (D) and significance (Sig).The predictive powers of the GA- MLR models are studied using leave-one-out (LOO) cross-validation and external test set. The predictive ability of the GA-MLR models with two-three selected molecular descriptors was found to be satisfactory. The developed QSPR models can be used to predict the property of compounds not yet synthesized. تفاصيل المقالة
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        2 - Structural Relationship Study of Octanol-Water Partition Coefficient of the Compounds in kesum Essential Oil Using GA-MLR and GA-ANN Methods
        Atefehsadat Navabi Tahereh Momeni Isfahani
        Essential Oils are highly concentrated substances the subtle, aromatic and volatile liquids. The use of essential oils is largely widespread in foods, deodorants, pharmaceuticals, drinks, cosmetics, medicine and embalming antiseptics especially with aromatherapy becomin أکثر
        Essential Oils are highly concentrated substances the subtle, aromatic and volatile liquids. The use of essential oils is largely widespread in foods, deodorants, pharmaceuticals, drinks, cosmetics, medicine and embalming antiseptics especially with aromatherapy becoming increasingly popular. The lipophilicity of an organic compound can be described by a partition coefficient, logP, which plays a significant role in drug discovery and compound design. A data set of 40 compounds in the essential oil of kesum was randomly divided into 3 groups: training, test and validation sets consisting of 70%, 15% and 15% of data point, respectively. A large number of molecular descriptors were calculated with Dragon software. The Genetic Algorithm - Multiple Linear Regressions (GA-MLR) and genetic algorithm -artificial neural network (GA-ANN) were employed to design the Quantitative Structure-Property Relationship (QSPR) models. The predictive powers of the QSPR model was discussed using Coefficient of determination (R2), Absolute Average Deviation (AAD) and the Mean Squared Error (MSE). The R2 and MSE values of the MLR model were calculated to be 0.734 and 0.194 respectively. The R2 and MSE values for the training set of the ANN model were calculated to be 0.9905 and 2×10-4 respectively. Comparison of the results revealed that the application the GA-ANN method gave better results than GA-MLR method تفاصيل المقالة
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        3 - Quantitative Structure- Property Relationship(QSPR) Study of 2-Phenylindole derivatives as Anticancer Drugs Using Molecular Descriptors
        samira Bahrami fatemeh shafiei Azam Marjani Tahereh Momeni Isfahani
        A QSPR study on a series of 2-Phenylindole derivatives as anticancer agents was performed to explore the important molecular descriptor which is responsible for their thermodynamic properties such as heat capacity (Cv) and entropy(S).Molecular descriptors were calculate أکثر
        A QSPR study on a series of 2-Phenylindole derivatives as anticancer agents was performed to explore the important molecular descriptor which is responsible for their thermodynamic properties such as heat capacity (Cv) and entropy(S).Molecular descriptors were calculated using DRAGON software and the Genetic Algorithm (GA) and backward selection procedure were used to reduce and select the suitable descriptors. Multiple Linear Regression (MLR) analysis was carried out to derive QSPR models, which were further evaluated for statistical significance such as squared correlation coefficient (R2) root mean square error (RMSE), adjusted correlation coefficient (R2adj) and fisher index of quality (F).The multicollinearity of the descriptors selected in the models were tested by calculating the variance inflation factor (VIF), Pearson correlation coefficient (PCC) and the DurbinWatson (DW) statistics. The predictive powers of the MLR models were discussed using Leave-One-Out Cross-Validation (LOOCV) and test set validation methods. The best QSPR models for prediction the Cv(J/molK) and S(J/molK), having squared correlation coefficient R2 =0.907 and 0.901, root mean squared error RMSE=2.019 and RMSE= 2.505, and cross-validated squared correlation coefficient R2 cv = 0.902 and 0.889, respectively. The statistical outcomes derived from the present study demonstrate good predictability and may be useful in the design of new 2-Phenylindole derivatives. تفاصيل المقالة