HGH-FRAG (176-191)

HGH Fragment 176-191 is a synthetic peptide matching residues 176 to 191 at the C-terminus of human growth hormone (hGH), cyclized through a disulfide bond between its two cysteines. It belongs to a series of C-terminal hGH peptides synthesized to locate the parts of the hormone responsible for its effects on blood glucose and fat metabolism. Rat studies compared the 176-191 peptide with neighboring fragments, and the overlapping 177-191 sequence was studied for antilipogenic action, adipocyte glucose transport and lipase activity. Research Market supplies HGH Fragment 176-191 with purity and identity data for each lot reported on its certificate of analysis. It is sold strictly for laboratory research use.

Chemical structure and identification

• Molecular formula: C₇₈H₁₂₃N₂₃O₂₂S₂
• Molecular weight: 1799.1 g/mol
• CAS number: 66004-57-7
• PubChem CID: 16131230
• Amino acid sequence: Phe-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe (FLRIVQCRSVEGSCGF; Cys7–Cys14 disulfide)
• Synonyms: Somatotropin (176-191), hGH (176-191)
• Form: Lyophilized powder
• Analytical methods: RP-HPLC for purity and mass spectrometry for identity, reported on the batch certificate of analysis

Research applications

• C-terminal fragment mapping: In normal rats, synthetic hGH 172-191, 176-191, 177-191 and 178-191 produced a short-lived rise in blood glucose and a more sustained rise in plasma insulin, while the shorter 179-191 and 180-191 peptides were inert [1]
• Antilipogenic activity: The overlapping synthetic fragment hGH 177-191 showed antilipogenic activity matching that of intact hGH, with no significant lipolytic effect on glycerol release from rat epididymal fat pads [2]
• Adipocyte glucose transport: In adipocytes from genetically obese Zucker rats, hGH 177-191 reduced basal and insulin-stimulated 2-deoxyglucose uptake and was more active than intact hGH at equimolar concentrations [3]
• Lipase and lipogenic enzymes: The 177-191 domain (AOD9401) stimulated hormone-sensitive lipase and inhibited acetyl-CoA carboxylase in isolated rat adipose tissue, and 20-day treatment of obese Zucker rats reduced average adipocyte diameter from 110 to 80 µm [4]
• Human adipose tissue in vitro: AOD-9401 increased lipolytic and decreased lipogenic activity in isolated adipose tissue from obese rodents and humans, and orally treated ob/ob mice showed an acute increase in energy expenditure and fat oxidation [5]

Reference citations

1. Ng F.M. et al. (1978). Hyperglycemic action of synthetic C-terminal fragments of human growth hormone. Am J Physiol, 234(5):E521–E526. PMID 645904 · DOI
2. Wu Z. et al. (1993). Antilipogenic action of synthetic C-terminal sequence 177-191 of human growth hormone. Biochem Mol Biol Int, 30(1):187–196. PMID 8358331
3. Wijaya E. et al. (1993). Effect of an antilipogenic fragment of human growth hormone on glucose transport in rat adipocytes. Biochem Mol Biol Int, 31(3):543–552. PMID 8118430
4. Ng F.M. et al. (2000). Molecular and cellular actions of a structural domain of human growth hormone (AOD9401) on lipid metabolism in Zucker fatty rats. J Mol Endocrinol, 25(3):287–298. PMID 11116208 · DOI
5. Heffernan M.A. et al. (2000). Effects of oral administration of a synthetic fragment of human growth hormone on lipid metabolism. Am J Physiol Endocrinol Metab, 279(3):E501–E507. PMID 10950816 · DOI

Compound data from PubChem CID 16131230. Literature summaries describe published preclinical research and are not claims about this product’s effects in humans or animals.