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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.
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]
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]
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:
Comparative characterisation against AOD-9604, isolating the contribution of the N-terminal tyrosine.[1]
Analytical method development resolving the unmodified fragment from the tyrosinated analogue and their metabolites.[1]
Disulfide integrity and stability studies across oxidising and reducing conditions.
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.
