Sclera-Derived Peptides

1 Identity

Compositionally undefined animal-tissue preparation. Not a molecular entity, not a defined mixture, and not classifiable to a molecular class: mammalian sclera is a dense type-I-collagen connective tissue, so any hydrolysate of it is a heterogeneous peptide population whose composition is a property of the species, the tissue lot, the extraction route and the fractionation cut-off rather than of any structure. No supplier has declared species of origin, extraction route, amino-acid composition or a molecular-weight distribution. and occasionally traded under Khavinson-style "cytomedine" or "peptide bioregulator" branding. No CAS number, no PubChem CID, no monograph and no reference standard exists under any of these names. The name identifies a starting tissue, not a substance.

Sequence

None, and none can be stated. An extract has no sequence: no sequence, no residue count, no molecular weight and no gene product stands behind this name. Any document offering a sequence, a residue count or a single molecular weight under this name has run a synthetic-peptide template against a preparation that has no analyte, and was not read by whoever signed it.

Molecular formula

None. A compositionally undefined tissue fraction has no molecular formula, and inventing one to fill the space is the specific failure this record exists to prevent.

Average mass

Not established, and not establishable from anything on offer. An extract has a molecular-weight distribution rather than a molecular weight. The only honest deliverable is an SE-HPLC or SDS-page profile with a stated numeric acceptance window, and any single average mass printed for this article is a fabrication irrespective of how many decimal places it carries.

Monoisotopic mass

Not applicable and not computable. There is no formula from which to compute one, and nothing plausible-looking is put in its place: the emptiness is itself the finding.

Salt / variant note

This is the record in which substitution cannot be detected by arithmetic, and that absence is itself the finding: with no target mass there is no check to run, which is exactly what makes the article attractive to a dishonest supplier. The commercial variance is compositional rather than molecular and the candidate contents fall into four groups. (1) Generic type-I collagen or gelatin hydrolysate from bovine hide, porcine skin or fish. Sclera IS type-I collagen, so amino-acid analysis of a hide-derived gelatin hydrolysate and of a genuine scleral hydrolysate are near-identical and hydroxyproline discriminates neither; species and tissue can be established only by PCR against species-specific mitochondrial markers or by LC-MS/MS proteotypic peptide markers, and no supplier has offered either. (2) Bulking agents that build a convincing lyophilized cake and carry the declared vial weight: mannitol C6H14O6, 182.172 average / 182.07903 monoisotopic; lactose C12H22O11, 342.297 average / 342.11621 monoisotopic; glycine C2H5NO2, 75.067 average / 75.03203 monoisotopic. None is visible on a peptide-purity chromatogram at 214 nm without refractive-index, ELSD or charged-aerosol detection. (3) Bovine serum albumin, roughly 66.4 kDa, as protein filler. (4) A single defined synthetic peptide sold under a tissue name — Epitalon, Ala-Glu-Asp-Gly, C14H22N4O9, 390.349 average / 390.13868 monoisotopic, [M+H]+ 391.14596 — which is the substitution most often supplied under bioregulator branding and the only case here a mass spectrometer can settle: a sharp single low-mass peak under a tissue-extract label proves the article is a defined synthetic tetrapeptide and not an extract at all.

2 Class & testing panel

Form

Single article

Testing panel

P7 — panel definition

3 Primary sources & evidence

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

Essentially no indexed primary literature exists under this product name. The adjacent body of work is the Russian-language cytomedine and peptide-bioregulator corpus on animal-tissue extracts, which is largely non-indexed in Western databases, rarely reports the composition of the test article, and contains no controlled human trial identifiable by an NCT number. Under this name, PubMed and ClinicalTrials.gov carry no controlled human trial and no characterized in-vitro work on a defined article. The citation index page states that absence explicitly and does not substitute literature about a different, defined peptide — which is the most common way a page like this becomes misleading, and the reason the substitution is prohibited by rule rather than discouraged by preference.

4 Storage & specification

Storage

Held lyophilized at -20 degrees C plus or minus 5 degrees C, desiccated and light-protected, in a physically segregated storage zone away from synthetic API. The segregation is part of the specification rather than a convenience: no stability-indicating method exists that could detect degradation of an undefined tissue fraction, and cross-contamination could not be traced analytically after the fact, so it is prevented physically.

Shelf life

With no stability-indicating method available for a compositionally undefined tissue fraction, the article is dated from the manufacturer's declared extraction and lyophilization date, carried onto the lot record at receipt and rotated first-expiry-first-out on that date rather than on a company-derived interval. The attributes that limit it are moisture content of the cake, closure integrity, and drift in the SE-HPLC or SDS-page profile that serves as the lot comparator, that profile being the only numeric acceptance window the article supports.