Enobosarm-d₄is intended for use as an internal standard for the quantification of enobosarm by GC- or LC-MS. Enobosarm is a non-steroidal selective androgen receptor modulator (SARM; K_i= 0.0038 µM in a radioligand binding assay).¹It is a partial agonist of the androgen receptor (IC₅₀= 0.0364 µM in a transactivation assay) and inhibits the proliferation of 22Rv1, DU145, LNCaP, and VCaP prostate cancer cells (IC₅₀s = 24.77, 44.55, 20.9, and 24.47 µM, respectively).²Enobosarm (0.001 and 0.01 µM) inhibits lipogenesis in isolated rat adipocytes.³It increases the weights of the prostate gland and seminal vesicles, markers of androgenic activity, and the levator ani muscle, a marker of anabolic activity, in castrated rats (ED₅₀s = 0.12, 0.39, and 0.03 mg/day, respectively).¹

1.Kim, J., Wu, D., Hwang, D.J., et al.The para substituent of S-3-(phenoxy)-2-hydroxy-2-methyl-N-(4-nitro-3-trifluoromethyl-phenyl)-propionamides is a major structural determinant of in vivo disposition and activity of selective androgen receptor modulatorsJ. Pharmacol. Exp. Ther.315(1)230-239(2005) 2.Bassetto, M., Ferla, S., Pertusati, F., et al.Design and synthesis of novel bicalutamide and enzalutamide derivatives as antiproliferative agents for the treatment of prostate cancerEur. J. Med. Chem.118230-243(2016) 3.Leciejewska, N., Pruszynska-Oszmalek, E., Bien, J., et al.Effect of ostarine (enobosarm/GTX024), a selective androgen receptor modulator, on adipocyte metabolism in Wistar ratsJ. Physiol. Pharmacol.70(4)525-533(2019)