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Fragment 176-191 Research Standard
Fragment 176-191 (CAS 66004-57-7), indexed as somatotropin (176-191), is the unmodified C-terminal peptide of human growth hormone, supplied as a 5 mg lyophilized powder in a 3 mL vial. It is a cyclic disulfide-containing peptide fragment, and it is not the same material as AOD-9604 — a distinction the two are routinely sold without.
Mechanism of Action & Research Context
This fragment has no identified receptor and no established mechanism. Stating that plainly is more useful than assembling a mechanism section from claims made about a related molecule.
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What distinguishes it from AOD-9604. AOD-9604 is the hGH C-terminal fragment residues 177–191 carrying an additional tyrosine at the N-terminus, and it holds a different CAS number. This product is the fragment without that modification. Any data generated on AOD-9604 — including its metabolite profile — describes that molecule, not this one.[1]
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The region is analytically characterised, the unmodified fragment less so. Work on the C-terminal region has established detection methods and metabolite behaviour for the tyrosinated analogue. Independent characterisation of the unmodified 176-191 fragment is thinner, so comparative work between the two is a genuine gap rather than a settled question.[1]
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Disulfide-containing. The fragment carries a cyclic disulfide, which matters for handling: reducing conditions will open it, and the reduced and oxidised forms are different analytes.
Research Applications
Primary fields of laboratory investigation include:
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Comparative characterisation against AOD-9604, isolating the contribution of the N-terminal tyrosine.[1]
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Analytical method development resolving the unmodified fragment from the tyrosinated analogue and their metabolites.[1]
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Disulfide integrity and stability studies across oxidising and reducing conditions.
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Peptide reference material for chromatographic and mass-spectrometric identification.
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
- Cox HD, Smeal SJ, Hughes CM, Cox JE, Eichner D. Detection and in vitro metabolism of AOD9604. Drug Test Anal. 2015;7(1):31–38. doi:10.1002/dta.1715
Storage & Handling
Store at controlled room temperature, sealed and protected from light.
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.
