Cardiogen

Cardiogen is a synthetic tetrapeptide from the Khavinson bioregulator series developed at the St Petersburg Institute of Bioregulation and Gerontology. Its sequence is Ala-Glu-Asp-Arg, written AEDR, with the molecular formula C18H31N7O9 and a molecular weight of 489.5 g/mol. PubChem holds the structure as CID 11583989, deposited from a chemical library rather than under the commercial name. Material is supplied as a lyophilized (freeze-dried) solid. No CAS number resolves for this peptide in a public database, so that field is reported as unassigned.

The name needs care, because it is shared. In PubChem the word Cardiogen appears as a synonym on the record for L-carnitine, an unrelated small molecule, and a similar name belongs to a radiopharmaceutical product. Searching the name alone returns the wrong chemistry; a search on the sequence is the reliable route. As elsewhere in the series, the name is a commercial designation from a programme that labelled compounds after tissues, not a statement of what the molecule does.

The programme began in the 1970s with polypeptide fractions from animal organs, then moved to short synthetic sequences said to reproduce their activity. Cardiogen belongs to that second generation; its name enters PubMed-indexed literature in 2009 and the sequence in 2013.

The compound-specific record is two papers. A 2009 study in senescent rats used the peptide in a transplantable sarcoma model (PubMed 20396706), and a second Russian-language report from the same year used it in organotypic tissue culture (PubMed 20210190). The strongest chemistry is a 2013 binding study measuring Ala-Glu-Asp-Arg alongside five other short peptides against labelled wheat histones and histone-oligonucleotide complexes (PubMed 23581987). Beyond these it appears only in series-level reviews and a docking study covering twenty-six ultrashort peptides (PubMed 36979488).

The record is thin. Only a handful of PubMed items concern this peptide, most from the originating group, several in Russian-language journals with English abstracts only. There is no published human trial, no toxicology package and no independent replication of the biological findings.

The mechanism proposed for this class is transcriptional rather than receptor-mediated. Its authors argue that peptides of two to four residues reach the nucleus, contact DNA and the N-terminal tails of histones, and shift expression of a small set of genes (PubMed 27909961; PubMed 31808038). Cardiogen enters that argument mainly through the 2013 quenching measurements, where its binding differed from the other peptides tested (PubMed 23581987).

The useful comparison is with Pinealon. Pinealon is Glu-Asp-Arg, C15H26N6O8, 418.40 g/mol; Cardiogen is the same three residues with an alanine added at the N-terminus, which puts it about 71 Da heavier. Both carry the basic guanidinium group of arginine, which separates them from acidic members such as Epitalon and Cartalax and changes their behaviour on ion-exchange media. A tripeptide and its N-extended tetrapeptide are different molecules, and a result for one does not transfer.

Two caveats sit with the evidence. The binding data are quenching constants from cell-free mixtures of peptide, histone and oligonucleotide, which measure association, not cellular consequence. The transport paper is a computational model. Neither establishes what the peptide does inside a cell.

Sealed lyophilized Cardiogen is held frozen at -20°C, shielded from light, in its original container. Lyophilized peptides take up water from air, so a container reaches ambient temperature before opening.

Repeated freeze-thaw cycles are avoided. Stability for a lot is documented on its Certificate of Analysis, not as a duration.

Reconstitution means returning a lyophilized compound to solution. No preparation procedure appears here: solvent and concentration belong to a study protocol. Cardiogen carries two free carboxyl side chains and a basic arginine side chain, and is handled as aqueous-soluble material.

Containing both acidic and basic groups, its net charge changes sharply with pH, which matters for buffer choice and chromatography. Solubility and water content for a lot appear on its Certificate of Analysis.

Identity and purity of research-grade Cardiogen are established by reverse-phase HPLC and mass spectrometry. Verified purity is documented per lot on the Certificate of Analysis. Sequence confirmation is the specification to read first, since this peptide has no public CAS or name-indexed database entry to check against.

Arginine-containing peptides are often supplied as acetate or trifluoroacetate salts, and counter-ion content moves the reported mass away from the free-peptide figure. Small, very polar peptides also retain poorly on standard reverse-phase columns, so the method matters when comparing COAs.

Cardiogen sits in a group of short peptides and preparations from one programme.

• Pinealon.
  The tripeptide Glu-Asp-Arg, Cardiogen without its N-terminal alanine.
• Epitalon.
  The tetrapeptide Ala-Glu-Asp-Gly, the same first three residues ending in glycine.
• Cartalax.
  Indexed as the tripeptide Ala-Glu-Asp, the acidic core shared with Epitalon.
• Testagen and Prostamax.
  Further defined tetrapeptides on the same evidence footing.
• Vilon, Ovagen and Thymalin.
  The dipeptide Lys-Glu, a compound with no settled sequence, and the preparation that preceded the synthetics.

Levdik NV, Knyazkin IV (2009). Tumor-modifying effect of cardiogen peptide on M-1 sarcoma in senescent rats. Bull Exp Biol Med.
PubMed 20396706

Fedoreyeva LI, Smirnova TA, et al. (2013). Interaction of short peptides with FITC-labeled wheat histones and their complexes with deoxyribooligonucleotides. Biochemistry (Mosc).
PubMed 23581987

Khavinson VK, Lin’kova NS, Tarnovskaya SI (2016). Short Peptides Regulate Gene Expression. Bull Exp Biol Med.
PubMed 27909961

Khavinson V, Linkova N, et al. (2020). Peptide Regulation of Cell Differentiation. Stem Cell Rev Rep.
PubMed 31808038

Khavinson VK, Linkova NS, et al. (2023). Feasibility of Transport of 26 Biologically Active Ultrashort Peptides via LAT and PEPT Family Transporters. Biomolecules.
PubMed 36979488

Chalisova NI, Lesniak VV, Balykina NA, et al. (2009). [The effect of the amino acids and cardiogen on the development of myocard tissue culture from young and old rats]. Adv Gerontol.
PubMed 20210190

Cardiogen is stocked in one format: a sealed lyophilized vial from a single supplier brand, listed at a 20mg fill. The per-vial strength is a product specification. Each lot is batch tested with a published Certificate of Analysis documenting verified purity and identity, the identity reference that counts for a compound with no public CAS record.

• Browse all Cardiogen research products
• Verified Peptides Cardiogen, 20mg lyophilized vial

These products are sold for Research Use Only and are not intended for human consumption.