Analysis of Structure-Toxicity Relationships for A Series of Amide Herbicides Using Statistical Methods and Neural Network

Abstract

Structure-toxicity relationships were studied for a set of 44 herbicides by means of principal component analysis (PCA), multiple regression analysis (MRA), and neural network (NN). The values of log LD50 (lethal dose 50, acute, oral, rat) of the studied compounds were well correlated with the descriptors encoding the chemical structures. Considering the pertinent descriptors, a correlation coefficient of 0.90 (n = 41) was obtained for the NN model with a configuration of 4-3-1 (and 0.92 (n = 41) with a configuration of 4-5-1). To evaluate the contribution of each descriptor on the activity, log LD50 was calculated by removing each descriptor a part. This approach provides the tendency of a descriptor to be favourable (or not) to the activity.

Use of neural networks as tool for the control of the biological pollution

“…In addition to the good results, we attempted the evaluation of the contribution [13][14][15], of each environmental parameter to the models. We also calcu- lated the contributions of variables to equation 3 according to the Gore method [16].…”

“…According to the results obtained, one concludes that nonlinear models [14][15][16] are the adapted tool to account for the relationships between environmental parameters and pollution-indicator bacteria. The obtained models suggest their use as control of ponds systems on the basis of the parameters studied.…”

Modeling the toxicity of amide herbicides using the electrotopological state

“…Toxicity data were obtained from Jager [20], Thompson [21], and Bohmont et al [22], all of which had also been cited by Zakarya et al [23]. All the data were reported as mg/kg for oral, acute toxicity to male rats.…”

Artificial neural network-based equation to predict the toxicity of herbicides on rats

“…In addition, it should be noted that the most of these QSAR models were obtained with structurally similar chemicals such as amide herbicides [67,68], sulphonylurea and phenylurea herbicides [69,70] or organophosphorus pesticides [71].…”