title: A new in silico classification model for ready biodegradability, based on molecular fragments.
abstract: Regulations such as the European REACH (Registration, Evaluation, Authorization and restriction of Chemicals) often require chemicals to be evaluated for ready biodegradability, to assess the potential risk for environmental and human health. Because not all chemicals can be tested, there is an increasing demand for tools for quick and inexpensive biodegradability screening, such as computer-based (in silico) theoretical models. We developed an in silico model starting from a dataset of 728 chemicals with ready biodegradability data (MITI-test Ministry of International Trade and Industry). We used the novel software SARpy to automatically extract, through a structural fragmentation process, a set of substructures statistically related to ready biodegradability. Then, we analysed these substructures in order to build some general rules. The model consists of a rule-set made up of the combination of the statistically relevant fragments and of the expert-based rules. The model gives good statistical performance with 92%, 82% and 76% accuracy on the training, test and external set respectively. These results are comparable with other in silico models like BIOWIN developed by the United States Environmental Protection Agency (EPA); moreover this new model includes an easily understandable explanation.
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Via G. La Masa 19, 20156 Milano, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Lombardo
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Via G. La Masa 19, 20156 Milano, Italy.
authors.forename: Fabiola
authors.initials: F
authors.lastname: Pizzo
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Via G. La Masa 19, 20156 Milano, Italy. Electronic address: emilio.benfenati@marionegri.it.
authors.forename: Emilio
authors.initials: E
authors.lastname: Benfenati
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Via G. La Masa 19, 20156 Milano, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Manganaro
authors.affiliation: Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Piazza L. da Vinci 32, 20133 Milano, Italy.
authors.forename: Thomas
authors.initials: T
authors.lastname: Ferrari
authors.affiliation: Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Piazza L. da Vinci 32, 20133 Milano, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Gini
mesh_terms: D001673:Biodegradation, Environmental; D003198:Computer Simulation; D062126:Databases, Chemical; D004785:Environmental Pollutants / Q000737:chemistry* / Q000378:metabolism*; D008954:Models, Biological; D008958:Models, Molecular; D021281:Quantitative Structure-Activity Relationship; D018570:Risk Assessment; D012984:Software
chemical_list: D004785:Environmental Pollutants
keywords: Fragment-based model; QSAR; REACH; Ready biodegradability; SARpy