Cortagen

1 Identity

Short-chain bioregulators (Khavinson peptides). Not Glandokort, which is a Cytomax-class tissue-extract oral capsule of undeclared composition and holds its own record; the two are routinely conflated because both are described in the source literature by the same organ.

Sequence

H-Ala-Glu-Asp-Pro-OH (AEDP). Four residues, all L, free N-terminal alpha-amino group, free C-terminal carboxyl, no disulfide, no acylation, no amidation, no non-proteinogenic residue. Three carboxyl groups (Glu2 side chain, Asp3 side chain, C-terminal Pro) against a single basic center, the N-terminal amine, so the molecule is strongly acidic. No aromatic residue and therefore no 280 nm chromophore. One feature is specific to this member of the class: the C-terminal proline is a secondary amine in the backbone, so the Asp3-Pro4 bond is an aspartyl-prolyl linkage, which is the classically acid-labile peptide bond and is the one predictable chemical liability this otherwise inert tetrapeptide carries.

Molecular formula

C17H26N4O9 (free acid). The formula and both masses in this record follow from the tetrapeptide composition rather than from a supplier declaration: for this class of peptides, formula, weight and CAS number are not independently verified in the public record.

Average mass

430.414 Da (C17H26N4O9), on IUPAC 2021 conventional atomic weights.

Monoisotopic mass

430.1700 Da neutral. Working ions: [M+H]+ m/z 431.1773, [M-H]- m/z 429.1627, [M+Na]+ m/z 453.1592. A plus or minus 5 ppm window on the neutral is plus or minus 0.0022 Da; negative mode is the sensible choice on a molecule with three carboxylates.

Salt / variant note

(1) the article-substitution risk is first and it is not an analytical problem but A procurement one. In the originating program the AC- prefix marks the synthesized line and the A- prefix marks the tissue-extract line; Glandokort is the A-17 adrenal Cytomax, an oral capsule declaring "peptide complex A-17" containing eight amino acids at 20 mg per capsule with microcrystalline cellulose, hydroxypropyl methylcellulose and calcium stearate. Eight declared amino acids is not a tetrapeptide. A supplier who ships the extract under an adrenal-axis trade name has shipped an article with no molecular identity at all, and no test on a P1 panel returns a sensible result on it. (2) sequence permutations — ADEP, EADP, AEPD and the rest are all C17H26N4O9 at exactly 430.16998 and are excluded only by MS/MS b/y assignment or Edman. (3) near neighbors: Epitalon AEDG 390.349 / 390.13868, minus 40.07 Da; Cartalax AED 333.297 / 333.11721; Bronchogen AEDL 446.457 / 446.20128, plus 16.04 Da — and note that AEDL and the Ser analog SEDP (446.413 / 446.16489) collide at nominal 446, 82 ppm apart; AEDV 432.430 / 432.18563, plus 2.02 Da from Cortagen, the Pro-for-Val substitution and the closest confusable in the series; GEDP 416.387 / 416.15433; Prostamax KEDP 487.510 / 487.22783, the same C-terminal proline with Lys for Ala. (4) the aspartyl-prolyl degradant: cleavage at the Asp3-Pro4 bond under acidic conditions gives the tripeptide AED (Cartalax, 333.297 / 333.11721) plus free proline — so this molecule's characteristic degradation product is another article in this catalog, the two are filled in the same facility, and that makes the aspartyl-prolyl bond a cross-contamination and mis-identification question as well as a stability one. (5) Salt forms: one basic center, light counterion load, but one mole of trifluoroacetate is 19.6 percent of the mass of a 430 Da article.

2 Class & testing panel

Form

Single article

Testing panel

P1 — panel definition

3 Primary sources & evidence

The index reports the design and provenance of the literature, not a conclusion about effect.

In vitro and rodent literature only, concentrated almost entirely in the publication network of the Saint Petersburg Institute of Bioregulation and Gerontology, published largely in Russian-language journals and their English translations, with sparse independent replication by unaffiliated laboratories. Group-level citations: PMID 12374906 (review); PMID 31808038, DOI 10.1007/s12015-019-09938-8 (review, and the source of the class's verbatim mechanistic claim); PMID 11276315 (rat study); PMID 23734519 and PMID 24003726 (reviews by the originating group, the second being the principal source for the class's human claims and not a primary randomized trial); PMID 32593244 (review). No compound-specific ClinicalTrials.gov registration for Cortagen and no controlled human trial were identified. No marketing authorization in any jurisdiction. The class evidence is graded D, and sequence-specific DNA recognition by a tetrapeptide is not a mainstream position in molecular biology and has not been independently replicated — a statement about the state of the literature, which this page carries.

4 Storage & specification

Storage

Lyophilized powder, -20 degrees C plus or minus 5 degrees C, desiccated with in-pack desiccant, protected from light. 2 to 8 degrees C is acceptable for transit and for working stock held no longer than 30 days; shipping validation covers a 72-hour excursion to 25 degrees C. Sealed vials are equilibrated to room temperature before opening. One handling instruction is specific to this molecule and is printed on the label rather than left to the technical note: acidic media are not specified for this article, because the Asp3-Pro4 bond is acid-labile, and any customer protocol calling for dilute acid should be referred to the technical note before use.

Shelf life

Provisional 24 months at -20 degrees C plus or minus 5 degrees C, assigned by protocol and not measured, pending the company's long-term and accelerated data on the first three lots. The indicating attribute is the aspartyl-prolyl cleavage product at 333.1172, not gross purity and not mass; a limit on that cleavage product is a named release test as well as the indicating attribute on stability. An all-L tetrapeptide with no methionine, no tryptophan and no disulfide will show nothing else moving, and the 6-month accelerated arm at 25 degrees C and 60 percent RH exists principally to force that one bond. Timepoints 0, 3, 6, 9, 12, 18 and 24 months. The label is shortened on data and never extended without a completed dataset.