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3D molecular model of S-23

Calculated reference model · not an experimental or batch-certified structure. All 28 atoms shown.

Model data & sources
  • Heavy atoms only; hydrogens are omitted from the reference display.
  • Source-defined stereochemistry is checked against the calculated coordinates; no energy-minimum, crystal or solution-structure claim is made.
  • Reference molecular species only; batch identity, purity, counterions and excipients are not certified.
Formula
C18H13ClF4N2O3
Method
RDKit ETKDGv3 / MMFF94s calculated reference conformer

S-23

By Kimera ChemsSelective Modulators

S-23 Research Standard

S-23 (CAS 1010396-29-8) is a nonsteroidal arylpropionamide selective androgen receptor modulator, supplied as a reference standard for androgen receptor pharmacology. Among the arylpropionamide SARMs it is notable for being characterised as a full agonist in vitro rather than a partial one, with high binding affinity — an inhibitory constant of 1.7 ± 0.2 nM.[1]

Mechanism of Action & Research Context

The molecular target is the androgen receptor (AR, NR3C4), a ligand-activated nuclear hormone receptor that functions as a transcription factor.

  • High-affinity full agonism. Ki = 1.7 ± 0.2 nM, identified as a full agonist in vitro. This makes it a useful upper-bound comparator in panels that also contain partial agonists such as AC-262536 and ACP-105.[1]

  • Quantified tissue divergence. In castrated male rats the ED50 was 0.43 mg/d in prostate against 0.079 mg/d in levator ani muscle — roughly a fivefold separation, and one of the few places in this literature where tissue selectivity is expressed as two numbers rather than a description.[1]

  • Gonadotropin suppression. In intact male rats treated for 14 days, S-23 alone suppressed LH by more than 50% at doses above 0.1 mg/d, with prostate size falling while levator ani size rose.[1]

  • Distinct genomic and non-genomic routes. Nonsteroidal SARMs and endogenous androgens engage AR through different signalling arms and assemble different AR/cofactor complexes at androgen-responsive enhancers, so the two ligand types are not interchangeable in mechanistic work.[4]

  • Coregulator recruitment and dimerisation. A SARM can drive AR transcriptional activity while producing markedly less AR homodimerisation than DHT and recruiting only a restricted subset of cofactors, with p160 coactivators SRC1, TIF2 and NCoA3 notably absent in yeast two-hybrid assays. Differential coregulator recruitment is the leading mechanistic account of tissue selectivity.[5]

Research Applications

Primary fields of in vitro and preclinical laboratory investigation include:

  • Competitive AR binding assays where a high-affinity full agonist anchor is needed.[1]

  • Dose-response and tissue-selectivity modelling using published ED50 separations as a benchmark.[1]

  • In vitro metabolite identification — ten phase I metabolites have been characterised in equine liver microsomes.[2]

  • Analytical and forensic method development. Reference material for chromatography-mass spectrometry identification, retention-time matching and metabolite characterisation.[3,4]

Analytical Documentation

Purity and identity vary by manufacturing lot. Kimera Chems does not publish a single fixed purity figure for this item; refer to the batch-specific Certificate of Analysis (COA) issued for the lot received, which reflects third-party analytical testing for that lot.

References

  1. Jones A, Chen J, Hwang DJ, Miller DD, Dalton JT. Preclinical characterization of a (S)-N-(4-cyano-3-trifluoromethyl-phenyl)-3-(3-fluoro,4-chlorophenoxy)-2-hydroxy-2-methyl-propanamide: a selective androgen receptor modulator for hormonal male contraception. Endocrinology. 2009;150(1):385–395. doi:10.1210/en.2008-0674
  2. Cutler C, Viljanto M, Taylor P, Hincks P, Biddle S, Van Eenoo P. Identification of equine in vitro metabolites of seven non-steroidal selective androgen receptor modulators for doping control purposes. Drug Test Anal. 2022;14(2):349–370. doi:10.1002/dta.3189
  3. Stacchini C, Botrè F, Comunità F, et al. Simultaneous detection of different chemical classes of selective androgen receptor modulators in urine by liquid chromatography-mass spectrometry-based techniques. J Pharm Biomed Anal. 2021;195:113849. doi:10.1016/j.jpba.2020.113849
  4. Narayanan R, Coss CC, Yepuru M, et al. Steroidal androgens and nonsteroidal, tissue-selective androgen receptor modulator, S-22, regulate androgen receptor function through distinct genomic and nongenomic signaling pathways. Mol Endocrinol. 2008;22(11):2448–2465. doi:10.1210/me.2008-0160
  5. Furuya K, Yamamoto N, Ohyabu Y, et al. Mechanism of the tissue-specific action of the selective androgen receptor modulator S-101479. Biol Pharm Bull. 2013;36(3):442–451. doi:10.1248/bpb.b12-00885

Storage & Handling

Store at controlled room temperature. Keep tightly closed. Liquid formats: do not refrigerate or freeze. Cold storage may cause the solution to cloud or precipitate. If this occurs, return to room temperature and mix until clear.

Storage guidance is a house recommendation. Analytical documentation is per-lot release testing.

Related Research Compounds

Research Use Only Disclaimer: This product is labeled and sold "For Research Use Only - NOT FOR HUMAN CONSUMPTION." It is not a drug, dietary supplement, food, cosmetic, or medical device, and it is not approved by the FDA or any other regulator for human or veterinary use. It is supplied to approved account holders as a research chemical for laboratory use and must be handled in accordance with applicable law.

Kimera Chems

Compounds That Survive Scrutiny

Research use only. Not for human or veterinary use.