Abstract
This research used electronic theory to model the biotransformation of 17α-ethinylestradiol (EE 2) under aerobic conditions in mixed culture. The methodology involved determining the Frontier Electron Density (FED) for EE 2 and various metabolites, as well as invoking well-established degradation rules to predict transformation pathways. We show that measured EE 2 metabolites are in good agreement with what is expected based on FED-based modeling. Initiating reactions occur at Ring A, producing metabolites that have been experimentally detected. When OH-EE 2 and 6AH-EE 2 are transformed, Ring A is cleaved before Ring B. The metabolites involved in these pathways have different estrogenic potentials, as implied by our analysis of the log P values and the hydrogen bonding characteristics. The OH-EE 2 and 6AH-EE 2 transformation pathways also show redox-induced electron rearrangement (RIER), where oxidation reactions lead to the reduction of carbon units present along the bond axis. Sulfo-EE 2 appears to be difficult to biotransform. These findings clarify theoretical and practical aspects of EE 2 biotransformation.
Original language | English (US) |
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Pages (from-to) | 760-768 |
Number of pages | 9 |
Journal | Environmental Science and Technology |
Volume | 46 |
Issue number | 2 |
DOIs | |
State | Published - Jan 17 2012 |
Externally published | Yes |
ASJC Scopus subject areas
- Chemistry(all)
- Environmental Chemistry