@article {56,
	title = {Reversible Photohydration of Trenbolone Acetate Metabolites: Mechanistic Understanding of Product-to-Parent Reversion through Complementary Experimental and Theoretical Approaches.},
	journal = {Environmental Science \& Technology},
	volume = {50},
	year = {2016},
	note = {CAPLUS AN 2016:126331(Journal; Online Computer File)},
	month = {2016},
	pages = {6753 - 6761},
	publisher = {American Chemical Society},
	abstract = {Photolysis expts. (in H2O and D2O) and quantum chem. calcns. were performed to explore the pH-dependent, reversible photohydration of trenbolone acetate (TBA) metabolites.  Photohydration of 17α-trenbolone (17α-TBOH) and 17β-trenbolone (17β-TBOH) occurred readily in simulated sunlight to yield hydrated products with incorporated H+ at C4 and OH- at either C5 (5-OH-TBOH) or C12 (12-OH-TBOH) in the tetracyclic steroid backbone.  Although unable to be elucidated anal., theory suggests preferred orientations of cis-12-OH-TBOH (relative to C13 methyl) and trans-5-OH-TBOH, with the former most thermodynamically stable overall.  Both expt. and theory indicate limited stability of trans-5-OH-TBOH at acidic pH where it undergoes concurrent, carbocation-mediated thermal rearrangement to cis-12-OH-TBOH and dehydration to regenerate its parent structure.  Expts. revealed cis-12-OH-TBOH to be more stable at acidic pH, which is the only condition where its reversion to parent TBA metabolite occurred.  At basic pH cis-12-OH-TBOH decayed quickly via hydroxide/water addn., behavior that theory attributes to the formation of a stable enolate resistant to dehydration but prone to thermal hydration.  In a noteworthy deviation from predicted theor. stability, 17α-TBOH photohydration yields major trans-5-OH-TBOH and minor cis-12-OH-TBOH, a distribution also opposite that obsd. for 17β-TBOH.  Because H+ and OH- loss from adjacent carbon centers allows trans-5-OH-TBOH to dehydrate at all pH values, the presumed kinetically controlled yield of 17α-TBOH photohydrates results in a greater propensity for 17α-TBOH reversion than 17β-TBOH.  Addnl. calcns. explored minor, but potentially bioactive, trenbolone analogs that could be generated via alternative rearrangement of the acidic carbocation intermediate. [on SciFinder(R)]},
	keywords = {trenbolone acetate metabolite reversible photohydration mechanism},
	isbn = {0013-936X},
	author = {Baltrusaitis, Jonas and Patterson, Eric V. and O{\textquoteright}Connor, Meghan and Qu, Shen and Kolodziej, Edward P. and Cwiertny, David M.}
}
@article {104,
	title = {H2S-Mediated Thermal and Photochemical Methane Activation.},
	journal = {ChemPhysChem},
	volume = {14},
	year = {2013},
	note = {CAPLUS AN 2013:1649184(Journal)},
	pages = {3960 - 3970},
	publisher = {Wiley-VCH Verlag GmbH \& Co. KGaA},
	abstract = {Sustainable, low-temp. methods for natural gas activation are crit. in addressing current and foreseeable energy and hydrocarbon feedstock needs.  Large portions of natural gas resources are still too expensive to process due to their high content of hydrogen sulfide gas (H2S) mixed with methane, deemed altogether as sub-quality or "sour" gas.  We propose a unique method of activation to form a mixt. of sulfur-contg. hydrocarbon intermediates, CH3SH and CH3SCH3, and an energy carrier such as H2.  For this purpose, we investigated the H2S-mediated methane activation to form a reactive CH3SH species by means of direct photolysis of sub-quality natural gas.  Photoexcitation of hydrogen sulfide in the CH4 + H2S complex resulted in a barrierless relaxation by a conical intersection to form a ground-state CH3SH + H2 complex.  The resulting CH3SH could further be coupled over acidic catalysts to form higher hydrocarbons, and the resulting H2 used as a fuel.  This process is very different from conventional thermal or radical-based processes and can be driven photolytically at low temps., with enhanced control over the conditions currently used in industrial oxidative natural gas activation.  Finally, the proposed process is CO2 neutral, as opposed to the current industrial steam methane reforming (SMR). [on SciFinder(R)]},
	keywords = {hydrogen sulfide mediated thermal photochem methane activation CAM B3LYP},
	isbn = {1439-4235},
	author = {Baltrusaitis, Jonas and de Graaf, Coen and Broer, Ria and Patterson, Eric V.}
}
@article {113,
	title = {Product-to-parent reversion of trenbolone: Unrecognized risks for endocrine disruption.},
	journal = {Science (Washington, DC, United States)},
	volume = {342},
	year = {2013},
	note = {CAPLUS AN 2013:1616444(Journal)},
	pages = {347 - 351},
	publisher = {American Association for the Advancement of Science},
	abstract = {Trenbolone acetate (TBA) is a high-value steroidal growth promoter often administered to beef cattle, whose metabolites are potent endocrine-disrupting compds.  We performed lab. and field phototransformation expts. to assess the fate of TBA metabolites and their photoproducts.  Unexpectedly, we obsd. that the rapid photohydration of TBA metabolites is reversible under conditions representative of those in surface waters (pH 7, 25{\textdegree}C).  This product-to-parent reversion mechanism results in diurnal cycling and substantial regeneration of TBA metabolites at rates that are strongly temp.- and pH-dependent.  Photoproducts can also react to produce structural analogs of TBA metabolites.  These reactions also occur in structurally similar steroids, including human pharmaceuticals, which suggests that predictive fate models and regulatory risk assessment paradigms must account for transformation products of high-risk environmental contaminants such as endocrine-disrupting steroids. [on SciFinder(R)]},
	keywords = {trenbolone metabolite reversion endocrine disruption environment risk},
	isbn = {0036-8075},
	author = {Qu, Shen and Kolodziej, Edward P. and Long, Sarah A. and Gloer, James B. and Patterson, Eric V. and Baltrusaitis, Jonas and Jones, Gerrad D. and Benchetler, Peter V. and Cole, Emily A. and Kimbrough, Kaitlin C. and Tarnoff, Matthew D. and Cwiertny, David M.}
}
@article {130,
	title = {Computational Studies of CO2 Activation via Photochemical Reactions with Reduced Sulfur Compounds.},
	journal = {Journal of Physical Chemistry A},
	volume = {116},
	year = {2012},
	note = {CAPLUS AN 2012:1254917(Journal; Online Computer File)},
	month = {2012///},
	pages = {9331 - 9339},
	publisher = {American Chemical Society},
	abstract = {Reactions between CO2 and reduced sulfur compds. (RSC), H2S and CH3SH, were investigated using ground and excited state d. functional theory (DFT) and coupled cluster (CC) methods to explore possible RSC oxidn. mechanisms and CO2 activation mechanisms in the atm. environment.  Ground electronic state calcns. at the CR-CC(2,3)/6-311+G(2df,2p)//CAM-B3LYP/6-311+G(2df,2p) level show proton transfer as a limiting step in the redn. of CO2 with activation energies of 49.64 and 47.70 kcal/mol, resp., for H2S and CH3SH.  On the first excited state surface, CR-EOMCC(2,3)/6-311+G(2df,2p)//CAM-B3LYP/6-311+G(2df,2p) calcns. reveal that energies of <250 nm are needed to form H2S-CO2 and CH3SH-CO2 complexes allowing facile hydrogen atom transfer.  Once excited, all reaction intermediates and transition states are downhill energetically showing either C-H or C-S bond formation in the excited state whereas only C-S bond formation was found in the ground state.  Environmental implications of these data are discussed with a focus on tropospheric reactions between CO2 and RSC, as well as potential for carbon sequestration using photocatalysis. [on SciFinder(R)]},
	keywords = {activation, carbon dioxide, photochem reaction, sulfur compd},
	isbn = {1089-5639},
	author = {Baltrusaitis, Jonas and Patterson, Eric V. and Hatch, Courtney.}
}
