Epitalon (epithalon) research reference: CAS, molecular weight, AEDG sequence, solubility and storage

Epitalon was developed at the St. Petersburg Institute of Bioregulation and Gerontology by Vladimir Khavinson's group as a synthetic tetrapeptide modelled on a pineal gland extract called epithalamin. Its name is spelled both epitalon and epithalon in the literature, and both refer to AEDG. The group has published cell and animal work over two decades, including a 2003 report of telomerase activity in cultured human somatic cells (Khavinson et al., 2003), a mouse lifespan and tumor-incidence study (Anisimov et al., 2003) and later work on gene expression in neuronal differentiation models (Khavinson et al., 2020).

Most of that body of work comes from one research network, and independent replication is limited. That is normal for a niche research peptide, and it is a good reason to read the primary papers rather than summaries. Epitalon is not an approved medicine in the US.

Most of AEDG's chemistry is unremarkable: four small residues, no sulfur, no aromatic ring. The exception is its C-terminal Asp-Gly pair. Aspartate side chains can attack the next backbone amide to form a five-membered succinimide ring, which then reopens to give a mixture of normal aspartate and isoaspartate. Glycine after aspartate removes the steric hindrance that slows this reaction elsewhere, and Asp-Gly is among the fastest sequences studied (Geiger and Clarke, 1987).

Isoaspartate has exactly the same mass as aspartate. A mass spectrum will not show it. What you see instead is a new peak close to the main one on reversed-phase HPLC, which is why a purity trace with good resolution is more informative for this peptide than a mass confirmation alone.

1. Keep the lyophilized powder sealed at -20 C or below with desiccant, away from light.
2. Warm the closed vial to room temperature before opening.
3. Dissolve only what you need, and freeze the rest of a stock in single-use aliquots.
4. Avoid long holds at room temperature or at pH above about 7 in solution; succinimide formation speeds up with both.

With two acidic side chains and a free C-terminus, AEDG is net negative and highly polar. Water is the first solvent to try and is usually enough. If a lot dissolves slowly, the charge-based approach in supplier guides such as GenScript's points to a small amount of dilute ammonium bicarbonate, but keep in mind that raising the pH also speeds Asp isomerization, so use the mildest condition that works and record it.

Since so much of the published work comes from one network, a few reading habits help. Check the model first: cultured cells, mice, rats or plant tissue (Khavinson is a co-author on a study that added epitalon and other short peptides to tobacco callus cultures; Fedoreyeva et al., 2017). Check what was measured and how, for example whether telomerase activity was measured by a TRAP assay and telomere length by a separate method. And check the compound: some older papers use epithalamin, the pineal extract, rather than the synthetic AEDG tetrapeptide, and the two should not be mixed up when comparing results.

A related line of work proposes that very short peptides such as AEDG enter cells and interact directly with DNA or chromatin. Fedoreyeva and colleagues reported fluorescence-labeled short peptides entering HeLa cell nuclei and binding oligonucleotides in vitro (Fedoreyeva et al., 2011). It's an interesting idea for a lab to test. It is still only a hypothesis.

AEDG is small and absorbs weakly in the UV, so HPLC detection runs at low wavelengths. Ask what wavelength was used, and look at the chromatogram near the main peak, where an isoaspartate form would appear.

1. Lot number matching the vial, lab name and a lookup route.
2. HPLC purity with the chromatogram and detection wavelength.
3. Mass near m/z 391.1 (positive) or 389.1 (negative). Identity by mass won't distinguish the isoaspartate form.
4. Measured quantity or net peptide content.
5. CAS 307297-39-8 and formula C14H22N4O9. A formula with more carbons or a much higher mass describes something else.

We list epitalon (catalog name Epithalon) in 10 mg and 50 mg vials for laboratory research. We do not have a published third-party lot report for it yet, so none is shown here. A report is available on request through the testing page, and it will be added to the COA dataset only when a report issued for our lot is in hand.