King's College London

Research portal

Elucidation of the biosynthetic pathways of boldenone in the equine testis

Research output: Contribution to journalArticle

Standard

Elucidation of the biosynthetic pathways of boldenone in the equine testis. / Viljanto, Marjaana J.; Kicman, Andrew T.; Walker, Christopher J.; Parkin, Mark C.; Wolff, Kim; Pearce, Clive M.; Scarth, James.

In: Steroids, Vol. 146, 01.06.2019, p. 79-91.

Research output: Contribution to journalArticle

Harvard

Viljanto, MJ, Kicman, AT, Walker, CJ, Parkin, MC, Wolff, K, Pearce, CM & Scarth, J 2019, 'Elucidation of the biosynthetic pathways of boldenone in the equine testis', Steroids, vol. 146, pp. 79-91. https://doi.org/10.1016/j.steroids.2019.03.011

APA

Viljanto, M. J., Kicman, A. T., Walker, C. J., Parkin, M. C., Wolff, K., Pearce, C. M., & Scarth, J. (2019). Elucidation of the biosynthetic pathways of boldenone in the equine testis. Steroids, 146, 79-91. https://doi.org/10.1016/j.steroids.2019.03.011

Vancouver

Viljanto MJ, Kicman AT, Walker CJ, Parkin MC, Wolff K, Pearce CM et al. Elucidation of the biosynthetic pathways of boldenone in the equine testis. Steroids. 2019 Jun 1;146:79-91. https://doi.org/10.1016/j.steroids.2019.03.011

Author

Viljanto, Marjaana J. ; Kicman, Andrew T. ; Walker, Christopher J. ; Parkin, Mark C. ; Wolff, Kim ; Pearce, Clive M. ; Scarth, James. / Elucidation of the biosynthetic pathways of boldenone in the equine testis. In: Steroids. 2019 ; Vol. 146. pp. 79-91.

Bibtex Download

@article{f6eb8a9faac2425592455eafcb5efcaf,
title = "Elucidation of the biosynthetic pathways of boldenone in the equine testis",
abstract = "Boldenone is an anabolic-androgenic steroid that is prohibited in equine sports. Urine from the uncastrated male horse contains boldenone that is thought to be of endogenous origin and thus a threshold ({\textquoteleft}cut-off{\textquoteright}) concentration has been adopted internationally for free and conjugated boldenone to help distinguish cases of doping from its natural production. The testis is likely to be a source of boldenone. Qualitative analysis was performed on extracts of equine testicular homogenates (n = 3 horses) incubated non-spiked and in the presence of its potential precursors using liquid chromatography tandem mass spectrometry (LC–MS/MS) and LC high resolution mass spectrometry (LC–HRMS). Samples were analysed both underivatised and derivatised to increase the certainty of identification. In addition to previously reported endogenous steroids, analysis of non-spiked testicular tissue samples demonstrated the presence of boldenone and boldienone at trace levels in the equine testis. Incubation of homogenates with deuterium or carbon isotope labelled testosterone and androstenedione resulted in the matching stable isotope analogues of boldenone and boldienone being formed. Additionally, deuterium and carbon labelled 2-hydroxyandrostenedione was detected, raising the possibility that this steroid is a biosynthetic intermediate. In conclusion, boldenone and boldienone are naturally present in the equine testis, with the biosynthesis of these steroids arising from the conversion of testosterone and androstenedione. However, additional work employing larger numbers of animals, further enzyme kinetic experiments and pure reference standards for 2-OH androstenedione isomers would be required to better characterize the pathways involved in these transformations.",
keywords = "Aromatase, Biosynthesis, Boldenone, Endogenous steroids, Equine, Testis",
author = "Viljanto, {Marjaana J.} and Kicman, {Andrew T.} and Walker, {Christopher J.} and Parkin, {Mark C.} and Kim Wolff and Pearce, {Clive M.} and James Scarth",
year = "2019",
month = jun,
day = "1",
doi = "10.1016/j.steroids.2019.03.011",
language = "English",
volume = "146",
pages = "79--91",
journal = "Steroids",
issn = "0039-128X",
publisher = "Elsevier Inc.",

}

RIS (suitable for import to EndNote) Download

TY - JOUR

T1 - Elucidation of the biosynthetic pathways of boldenone in the equine testis

AU - Viljanto, Marjaana J.

AU - Kicman, Andrew T.

AU - Walker, Christopher J.

AU - Parkin, Mark C.

AU - Wolff, Kim

AU - Pearce, Clive M.

AU - Scarth, James

PY - 2019/6/1

Y1 - 2019/6/1

N2 - Boldenone is an anabolic-androgenic steroid that is prohibited in equine sports. Urine from the uncastrated male horse contains boldenone that is thought to be of endogenous origin and thus a threshold (‘cut-off’) concentration has been adopted internationally for free and conjugated boldenone to help distinguish cases of doping from its natural production. The testis is likely to be a source of boldenone. Qualitative analysis was performed on extracts of equine testicular homogenates (n = 3 horses) incubated non-spiked and in the presence of its potential precursors using liquid chromatography tandem mass spectrometry (LC–MS/MS) and LC high resolution mass spectrometry (LC–HRMS). Samples were analysed both underivatised and derivatised to increase the certainty of identification. In addition to previously reported endogenous steroids, analysis of non-spiked testicular tissue samples demonstrated the presence of boldenone and boldienone at trace levels in the equine testis. Incubation of homogenates with deuterium or carbon isotope labelled testosterone and androstenedione resulted in the matching stable isotope analogues of boldenone and boldienone being formed. Additionally, deuterium and carbon labelled 2-hydroxyandrostenedione was detected, raising the possibility that this steroid is a biosynthetic intermediate. In conclusion, boldenone and boldienone are naturally present in the equine testis, with the biosynthesis of these steroids arising from the conversion of testosterone and androstenedione. However, additional work employing larger numbers of animals, further enzyme kinetic experiments and pure reference standards for 2-OH androstenedione isomers would be required to better characterize the pathways involved in these transformations.

AB - Boldenone is an anabolic-androgenic steroid that is prohibited in equine sports. Urine from the uncastrated male horse contains boldenone that is thought to be of endogenous origin and thus a threshold (‘cut-off’) concentration has been adopted internationally for free and conjugated boldenone to help distinguish cases of doping from its natural production. The testis is likely to be a source of boldenone. Qualitative analysis was performed on extracts of equine testicular homogenates (n = 3 horses) incubated non-spiked and in the presence of its potential precursors using liquid chromatography tandem mass spectrometry (LC–MS/MS) and LC high resolution mass spectrometry (LC–HRMS). Samples were analysed both underivatised and derivatised to increase the certainty of identification. In addition to previously reported endogenous steroids, analysis of non-spiked testicular tissue samples demonstrated the presence of boldenone and boldienone at trace levels in the equine testis. Incubation of homogenates with deuterium or carbon isotope labelled testosterone and androstenedione resulted in the matching stable isotope analogues of boldenone and boldienone being formed. Additionally, deuterium and carbon labelled 2-hydroxyandrostenedione was detected, raising the possibility that this steroid is a biosynthetic intermediate. In conclusion, boldenone and boldienone are naturally present in the equine testis, with the biosynthesis of these steroids arising from the conversion of testosterone and androstenedione. However, additional work employing larger numbers of animals, further enzyme kinetic experiments and pure reference standards for 2-OH androstenedione isomers would be required to better characterize the pathways involved in these transformations.

KW - Aromatase

KW - Biosynthesis

KW - Boldenone

KW - Endogenous steroids

KW - Equine

KW - Testis

UR - http://www.scopus.com/inward/record.url?scp=85063936991&partnerID=8YFLogxK

U2 - 10.1016/j.steroids.2019.03.011

DO - 10.1016/j.steroids.2019.03.011

M3 - Article

C2 - 30951760

AN - SCOPUS:85063936991

VL - 146

SP - 79

EP - 91

JO - Steroids

JF - Steroids

SN - 0039-128X

ER -

View graph of relations

© 2018 King's College London | Strand | London WC2R 2LS | England | United Kingdom | Tel +44 (0)20 7836 5454