Activity Characterization of Triazines Analogues: Statistical Parameters for Models Assessment

Correlation coefficients and associated squared values are used as parameters in validation of structure-activity relationship models. By using of the molecular descriptors family on structure-activity relationship method [1] the herbicidal activity of a sample of triazines analogues was modelled [2]. A number of three multivariate models proved to have estimation and prediction abilities [2]. Starting from the hypothesis that the measured activity of triazines analogue is a semiquantitative variable, the aim of the research was to analyzed the three previously reported models by using the Pearson, Spearman, Kendall’s and Gamma correlation coefficients. The structure-activity relationship models were previously reported [2]. The measured herbicidal activity of triazines analogues and the value estimated by the previously reported models were investigated by using the Pearson, Spearman, Kendall's τa, τb, τc and Gamma correlation coefficients (rPrs, ρSpm, τKen,a, τKen,b, τKen,c, Γ) and associated squared correlation coefficient (rPrs 2 , ρSpm 2 , τKen,a 2 , τKen,b 2 , τKen,c 2 , Γ 2 ). The results of investigation, express as correlation coefficients and associated 95% confidence intervals, squared correlation coefficient and Student’s t, respectively the parameter of the Z test were calculated and analyzed. The correlation coefficients obtained with all methods were statistical significant (p < 0.0001). The correlation coefficients vary according with the model as follow: • Model with two descriptors: from r = 0.6889 (τKen,c) - 95%CI [0.4370-0.8405] to r = 0.9855 (rPrs) - 95% CI [0.9694-0.9931]; • Model with three descriptors: from 0.7489 (τKen,c) - 95%CI [0.5321-0.8734] to the value equal with 0.9883 (rPrs) - 95% CI [0.9752-0.9944];