Research area

Short regulatory and thymic peptides

This group contains very short regulatory peptides (Epithalon, Cartalax) described by the Khavinson group and the thymic peptides thymosin alpha 1 and thymosin beta-4.

Epithalon (Ala-Glu-Asp-Gly) and Cartalax (Ala-Glu-Asp) are tetrapeptide and tripeptide members of a family of short peptide bioregulators. Much of the published work comes from a small number of laboratories, so independent confirmation of identity and purity is especially valuable.

Thymosin alpha 1 (28 residues) and thymosin beta-4 (43 residues) are N-terminally acetylated thymic peptides with a longer research history and a broader literature. The name TB-500 is used by some suppliers for thymosin beta-4 and by others for its short active fragment, so the mass on the COA decides which is supplied.

Compounds in this group

Compound	Type	Formula	Average mass (g/mol)	Listings
Cartalax	Peptide	C₁₂H₁₉N₃O₈	333.29	1
Epithalon	Peptide	C₁₄H₂₂N₄O₉	390.35	2
Thymalin	Peptide fraction (mixture)	mixture	n/a	1
Thymosin alpha 1	Peptide	C₁₂₉H₂₁₅N₃₃O₅₅	3108.28	2
Thymosin beta-4 (TB-500)	Peptide	C₂₁₂H₃₅₀N₅₆O₇₈S	4963.44	5
Thymulin	Peptide	C₃₃H₅₄N₁₂O₁₅	858.85	1

Analytical points for this group

Tiny, acidic peptides are polar; confirm that the HPLC method retains the main peak away from the solvent front.
Counter-ions can make up a large share of the powder mass for a peptide near 400 Da, so net peptide content is far below 100 %.
Acetylated N-termini have no free amine; peptide-sequencing methods that rely on one do not work.
For TB-500, the intact mass separates full-length thymosin beta-4 (about 4963 Da) from the Ac-LKKTETQ fragment (about 889 Da).

Guides

ExplainerPeptide Counter-Ions and Net Peptide Content: Why the Powder Weighs More Than the Peptide

TFA and acetate counter-ions, bound water and net peptide content explained, with a worked example of how a 1000 Da peptide becomes a 1228 Da salt.

ExplainerPeptide Sequence Notation Explained: One-Letter Codes, D-Amino Acids and Terminal Groups

How to read peptide names such as Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, and what the brackets, prefixes and suffixes mean for the mass.

GuideBatch-Specific COA Verification and Research Material Traceability

A practical chain-of-custody framework connecting a supplier record, received vial, independent report, internal review, and final disposition.

Frequently asked questions

Which compounds are in the short regulatory and thymic peptides group?

Cartalax, Epithalon, Thymalin, Thymosin alpha 1, Thymosin beta-4 (TB-500), Thymulin.

How should a batch of a short regulatory and thymic peptides compound be checked?

Tiny, acidic peptides are polar; confirm that the HPLC method retains the main peak away from the solvent front. Counter-ions can make up a large share of the powder mass for a peptide near 400 Da, so net peptide content is far below 100 %.

Other research areas

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