Purity
99.0%
Fill
10 mg
Vial
3 mL
Lot
GPB-4544
Neuro · CAS 129954-34-3
Selank
Tuftsin Analogue Heptapeptide
A tuftsin analogue carrying three prolines — conformationally stiff, which shows up as a slightly broadened peak that is not an impurity.
Selank is the peptide we field the most questions about, because its chromatogram looks marginally worse than it is. Three prolines in seven residues means the molecule interconverts between cis and trans amide rotamers on roughly the timescale of the separation, which broadens the main peak and can produce a shoulder that inexperienced buyers read as contamination. It is not. Running the column at 55 °C collapses the rotamers into a single sharp peak, and we include both the ambient and elevated-temperature traces on the certificate so you can see the same lot both ways.
Primary sequence
Physical data
- Molecular formula
- C₃₃H₅₇N₁₁O₉
- Molecular weight
- 751.88 g/mol
- CAS number
- 129954-34-3
- Appearance
- White lyophilised cake
- Solubility
- Soluble in water; slightly hygroscopic
- Storage
- Lyophilised: −20 °C, desiccated
Certificate of analysis
Lot GPB-4544| RP-HPLC purity (55 °C) | 99.0% area @ 214 nm |
|---|---|
| RP-HPLC purity (ambient) | 97.4% area — rotamer broadened |
| Identity (ESI-MS) | 752.5 [M+H]⁺ |
| Net peptide content | 81.6% |
| Water (Karl Fischer) | 3.7% |
| Bacterial endotoxin | < 0.15 EU/mg (LAL) |
Handling
- Expect peak broadening on ambient-temperature columns.
- Hygroscopic — weigh quickly, recap under dry gas if possible.
- Stable ~21 days at 2–8 °C in solution.
For laboratory research use only. Not for human or veterinary consumption, diagnostic or therapeutic use. Supplied to qualified researchers at institutional addresses.