Rates and product identification for trenbolone acetate metabolite biotransformation under aerobic conditions.
Trenbolone acetate metabolites are endocrine-active contaminants discharged into the aquatic environment in runoff from agricultural fields, rangelands, and concentrated animal feeding operations. To investigate the environmental fate of these compounds and their biotransformation mechanisms, the authors used inocula from a variety of different water sources and dosed biologically active microcosms with approximately 1400 ng/L of trenbolone acetate metabolites, including 17β-trenbolone, trendione, and 17α-trenbolone. To investigate aerobic biotransformation rates and interconversions between known trenbolone acetate metabolites, gas chromatography-tandem mass spectrometry was used to measure concentrations and assess product distributions as a function of time. High-resolution liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to characterize novel transformation products and potential transformation pathways. Kinetic analysis yields observed half-lives of approximately 0.9 d, 1.3 d, and 2.2 d for 17β-trenbolone, trendione, and 17α-trenbolone, respectively, at 20 °C, although colder conditions increased half-lives to 8.5 d and biphasic transformation was observed. Relative to reported faster attenuation rates in soils, trenbolone acetate metabolites are likely more persistent in aqueous systems. Product distributions indicate an enzymatic preference for biotransformation between trendione and 17β-trenbolone. The LC-MS/MS characterization indicates dehydrogenation products as the major detectable products and demonstrates that major structural elements responsible for bioactivity in steroids are likely retained during biotransformation.
Department of Civil Environmental Engineering, University of Nevada, Reno, Nevada, USA.
Emily A
EA
Cole
Department of Civil Environmental Engineering, University of Nevada, Reno, Nevada, USA.
Samantha A
SA
McBride
Department of Civil Environmental Engineering, University of Nevada, Reno, Nevada, USA.
Kaitlin C
KC
Kimbrough
Department of Civil Environmental Engineering, University of Nevada, Reno, Nevada, USA.
Jaewoong
J
Lee
Department of Civil Environmental Engineering, University of Nevada, Reno, Nevada, USA.
Eric A
EA
Marchand
Department of Civil and Environmental Engineering, University of Iowa, Iowa City, Iowa, USA.
David M
DM
Cwiertny
Interdisciplinary Arts and Sciences, University of Washington, Tacoma, Washington, USA.|Department of Civil and Environmental Engineering, University of Washington, Seattle, Washington, USA.
Edward P
EP
Kolodziej
D045930:Anabolic Agents / Q000032:analysis / Q000378:metabolism*; D000821:Animal Feed; D000818:Animals; D001673:Biodegradation, Environmental; D002851:Chromatography, High Pressure Liquid; D008401:Gas Chromatography-Mass Spectrometry; D006207:Half-Life; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D053719:Tandem Mass Spectrometry; D013696:Temperature; D014204:Trenbolone Acetate / Q000032:analysis* / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism
D045930:Anabolic Agents; D014874:Water Pollutants, Chemical; D014204:Trenbolone Acetate
Aerobic biotransformation; Product characterization; Rate constant; Trenbolone acetate