Extended Virtual Screening Strategies To Link Antiandrogenic Activities and Detected Organic Contaminants in Soils

Abstract

A tiered screening strategy based on extensive virtual fractionation and elucidation was developed to simplify identification of toxicants in complex environments. In tier1-virtual fractionation, multivariate analysis (MVA) was set up as an alternative of physical fractionation. In tier2-virtual structure elucidation, in-house quantitative structure-retention relationship (QSRR) models and toxicity simulation methods were developed to simplify nontarget identification. The efficiency of the tiered virtual strategy was tentatively verified by soil samples from a chemical park contaminated by antiandrogenic substances. Eight out of 18 sites were detected as antiandrogenic, while none of them exhibited androgenic agonist potencies. Sixty-seven peaks were selected for further identification by MVA, among which over 90% were verified in androgenic fractions in traditional effect-directed analysis (EDA). With 579 tentative structures generated by in silico fragmentation, 74% were elucidated by QSRR and 65% were elucidated by in silico toxicity prediction. All prior peaks were identified at different confidence levels with over 40% of the identified peaks above confidence level 2b, which has been increased over 40% with less than half of the time spent compared to traditional EDA. Such a combination of tiered virtual screening methods provides more efficient and rapid identifications of key toxicants at contaminated sites.

RETRACTED: Scene construction of nano particle system based on virtual technology

“…In virtual scenarios, the physical objects of multiple irregular forms need to be expressed by multiple nanoparticle systems, and each nanoparticle system in turn contains a large number of particles. Therefore, in order to construct the virtual scene better, the concept of object-oriented system hierarchy is introduced (Guo et al, 2017; Vilardi and Palma, 2017). The hierarchical structure of the nanoparticle system is shown in Figure 2, The construction process of nanoparticle system is shown in Figure 3.…”

Development and Application of Liquid Chromatographic Retention Time Indices in HRMS-Based Suspect and Nontarget Screening

“…This frequently happens in suspect and nontarget screening workflows, where the task is to identify the unknowns with a certain level of confidence . Therefore, confirming a structure becomes a task of eliminating false-positive candidates based on the available experimental information such as MS fragmentation pattern, retention time ( t R ), ionization behavior, and other evidence. − Prediction of t R for candidate substances can significantly decrease the number of false-positive candidates. ,− Nevertheless, it is often neglected due to the difficulties of accurately predicting and mapping it between different LC conditions.…”

Effect-Directed Analysis Based on the Reduced Human Transcriptome (RHT) to Identify Organic Contaminants in Source and Tap Waters along the Yangtze River

“…Dodecylbenzene sulfonic acid and PFOA are widely used surfactants, 2,4-dinitrophenol is an industrial intermediate, dibutyl phthalate is a widely used plasticizer, and bentazone is an herbicide. The wide occurrence of these suspects in various environmental matrices − and even in biological samples , has been reported. Furthermore, the estrogenic potencies of these 39 identified suspects were also evaluated.…”