3 research outputs found
Quantitative Structure–Activity Relationship Models for Ready Biodegradability of Chemicals
The
European REACH regulation requires information on ready biodegradation,
which is a screening test to assess the biodegradability of chemicals.
At the same time REACH encourages the use of alternatives to animal
testing which includes predictions from quantitative structure–activity
relationship (QSAR) models. The aim of this study was to build QSAR
models to predict ready biodegradation of chemicals by using different
modeling methods and types of molecular descriptors. Particular attention
was given to data screening and validation procedures in order to
build predictive models. Experimental values of 1055 chemicals were
collected from the webpage of the National Institute of Technology
and Evaluation of Japan (NITE): 837 and 218 molecules were used for
calibration and testing purposes, respectively. In addition, models
were further evaluated using an external validation set consisting
of 670 molecules. Classification models were produced in order to
discriminate biodegradable and nonbiodegradable chemicals by means
of different mathematical methods: <i>k</i> nearest neighbors,
partial least squares discriminant analysis, and support vector machines,
as well as their consensus models. The proposed models and the derived
consensus analysis demonstrated good classification performances with
respect to already published QSAR models on biodegradation. Relationships
between the molecular descriptors selected in each QSAR model and
biodegradability were evaluated