Identification of Endocrine Disruptor Biodegradation by Integration of Structure–activity Relationship with Pathway Analysis

Abstract

We present a SAR method that can predict estrogen-like endocrine disrupting chemical (EDC) activity as well as key biodegradation steps for detoxification. This method is based on a recent graph-mining algorithm developed by Kudo et al., which generates a set of descriptors from all potent chemical fragments (including rings). This method is novel in that it achieves chemical diversity in the training data set by sampling another data set of larger diversity. The model achieved an 83% accuracy prediction rate, and identified 1291 EDC candidates from the KEGG database. From this set of candidate compounds, bisphenol A was chosen for assay validation and biodegradation pathway analysis. Results showed that bisphenol A exhibited estrogen-like activity and was degraded in three distinct reactions. The prediction model provided information on the mechanism of the ligand-target binding, such as key functional groups involved. We focused on the enzyme commission number, which is useful for analyses of biodegradation pathways. Results identified oxygenases, ether hydrolases, and carbon-halide lyases as being important in the biodegradation pathway. This combined approach provided new information regarding the biodegradation of EDCs, and can potentially be extended to applications with transcriptomic, proteomic, and metabolomic data to provide a quick screen of biological activity and biodegradation pathway(s).

Catalytic degradation of bisphenol A by CoMnAl mixed metal oxides catalyzed peroxymonosulfate: Performance and mechanism

“…Generally, the mechanisms of SO 4 ÀÅ reacting with organic compounds should be illuminated as following: (1) oxidize aromatic compounds to their corresponding radical species through electron transfer [30]; (2) abstract a hydrogen from the organic structure and form a carbon centered radical, followed by the removal of the carboxylic group [30]; (3) react with alkenes and dienes to yield sulfate-substituted radicals [31]. However, Electron Paramagnetic Resonance (EPR) studies by Davies and Gilbert [32] demonstrated that the reaction of alkenes and dienes with the sulfate radical anions could yield sulfate-substituted radicals that existed for only five hundred microseconds, implying the extreme difficulty to observe the very unstable sulfate adducts in aqueous solutions.…”

“…The results of MMO/Oxone system were quite agreed with that of Co/Oxone homogeneous system [42], in which the optimum performance was observed at near-neutral condition (i.e., 4 < pH < 9). In order to understand the role of SO 4 ÀÅ and HO Å radicals in the MMO/Oxone system at different pH, alcohols including TBA and EtOH were added into the system as quenching agents. The rate of TBA reacting with hydroxyl radicals (3.8 Â 10 8 -7.6 Â 10 8 M À1 S À1 ) is approximately 1000-fold greater than that with sulfate radicals (4.5 Â 10 5 -9.1 Â 10 5 M À1 S À1 ) [43,44], and both of the two radical species react very rapidly with EtOH (k HO Å = 1.2 Â 10 9 -2.8 Â 10 9 M À1 S À1 ; k SO ÀÅ 4 = 1.6 Â 10 7 -7.8 Â 10 7 M À1 S À1 ).…”

“…Various technologies including physical, biological and chemical techniques have been developed to degrade BPA in aqueous solution, e.g., adsorption [3], biological degradation [4] and photocatalytic degradation [5]. BPA molecules can be quickly adsorbed from water by adsorbents but remain intact and pose potential threat to the environment.…”

Detoxification of Endocrine Disruptors in Water Using Visible-Light-Active Nanostructures: A Review

“…Therefore, efficient materially designed, green, and safe purification technology is in high demand to remove these emergent pollutants. Lots of effort, including physical, biological, ultrasonic, and chemical techniques, have been employed to treat wastewater. − Although the biodegradation method is favorable, but it is limited because of time consumption, bacterial counts, temperature, and salinity . By comparison, three techniques, namely, adsorption-based separation and chemical- and visible-light-induced photocatalytic degradation are the most efficient, promising, and advisible methods in the scientific community.…”

Visible-light photocatalytic mechanism of bisphenol-A on nano-Bi2O3: a combined DFT calculation and experimental study

“…Bisphenol-A (BPA), known as an endocrine disrupting chemical (EDC), is widely used as the monomer for the production of polycarbonate plastics (e.g., in baby bottles) and as a major component of the epoxy resin in food can linings and dental sealants, 1 and has been spreading over the environment and has deteriorated the generative function of some species of living things on the Earth. 2 Various methods have been developed to remove BPA from water, including chemical oxidation, 3,4 electrochemical oxidation, 5,6 biological methods, [7][8][9] and photocatalytic methods. [10][11][12] Among these methods, photocatalytic oxidation is one of the most promising techniques because of its high mineralization efficiency, extremely efficient degradation rate, and low toxigenicity, ideally producing carbon dioxide and water as the nal products.…”