Simulation of chemical metabolism for fate and hazard assessment. II CATALOGIC simulation of abiotic and microbial degradation

Abstract

The unprecedented pollution of the environment by xenobiotic compounds has provoked the need to understand the biodegradation potential of chemicals. Mechanistic understanding of microbial degradation is a premise for adequate modelling of the environmental fate of chemicals. The aim of the present paper is to describe abiotic and biotic models implemented in CATALOGIC software. A brief overview of the specificities of abiotic and microbial degradation is provided followed by detailed descriptions of models built in our laboratory during the last decade. These are principally new models based on unique mathematical formalism already described in the first paper of this series, which accounts more adequately than currently available approaches the multipathway metabolic logic in prokaryotes. Based on simulated pathways of degradation, the models are able to predict quantities of transformation products, biological oxygen demand (BOD), carbon dioxide (CO(2)) production, and primary and ultimate half-lives. Interpretation of the applicability domain of models is also discussed.

Methodology for studying biotransformation of polyfluoroalkyl precursors in the environment

“…For example, hydrolysis of ester bonds in 8:2 fluorotelomer citrate triester (8:2 TBC) and substantial formation of 8:2 FTOH occurred when dosed 60 Co-γ-irradiated sterile soil samples were extracted using the DSPE method [49]. The ester hydrolysis was enhanced by solvents with high dielectric constants (i.e., methanol and acetonitrile) compared with less polar solvents (e.g., MTBE and ethyl acetate).…”

“…Computer-aided pathway prediction relies on quantitative structure-activity (QSAR) models, which link biodegradation potential with molecular descriptors, such as physical-chemical descriptors and connectivity indexes generated from chemicalstructure fragments [60]. In-silico calculation is a quick, costeffective assessment to predict chemical-degradation potential, metabolites, and pathways at the screening level.…”

“…Different from UM-PPS, metabolism rules in CATALOGIC are hierarchically ranked by occurrence probabilities judged by expert knowledge and documented metabolic maps [60,62]. Metabolic trees could be generated with quantitative distributions of the precursor and subsequent transformation products.…”

UV-photodegradation of desipramine: Impact of concentration, pH and temperature on formation of products including their biodegradability and toxicity

“…The ready biodegradability values were predicted with Case Ultra, EPI Suite, and Oasis Catalogic according to OECD 301C MITI-I test guidelines (Ministry of International Trade and Industry, Japan) (OECD, 1992a). Oasis Catalogic also provides a biodegradation model according to OECD 301F, which is comparable to the experimental biodegradation test (MRT) used in this research (Dimitrov et al, 2011). In the Oasis Catalogic MITI-I and OECD 301F models, the ready biodegradability was predicted as a numerical value between 0 and 1, corresponding to 0% and 100% biodegradation, respectively.…”

Compartment‐Specific Screening Tools for Persistence: Potential Role and Application in the Regulatory Context

“…Because compartmental biodegradation half‐lives from simulation tests are not available for most chemicals, several approaches have been developed to derive primary and ultimate biodegradation half‐lives from screening information such as RBTs (Jaworska et al ; Aronson et al ; Junker et al ) and quantitative structure–activity relationships (QSARs) (e.g., BIOWIN models in Estimation Programs Interface [EPI] Suite [USEPA 2012a]; PBT‐Profiler [USEPA ]). Beyond that, degradation half‐lives for water, sediment, and soil are being predicted by computer models such as CATALOGIC (Dimitrov et al ) and ChemProp (Kühne et al ).…”