Semax: Research Compound Profile

This reference page summarizes the chemical identity, structure and analytical characteristics of Semax, a synthetic heptapeptide handled in laboratory settings as a research reference material. It is intended as encyclopedic background for researchers documenting compound identity, and it makes no claims about outcomes in humans or animals.

Identity and registry data

Semax is a synthetic, non-modified heptapeptide belonging to the class of adrenocorticotropic signalling factor (ACTH) fragment analogs. Its identifiers are established in public chemical databases:

• Compound name: Semax
• CAS Registry Number: 80714-61-0
• PubChem CID: 9811102
• Molecular formula: C₃₇H₅₁N₉O₁₀S
• Average molecular weight: 813.93 g/mol
• Peptide class: ACTH(4-7) analog with a C-terminal Pro-Gly-Pro extension

The single sulfur atom in the formula is contributed by the N-terminal methionine residue, which distinguishes Semax from many peptides of comparable length that contain no sulfur.

Amino acid sequence and structure

The primary sequence of Semax is Met-Glu-His-Phe-Pro-Gly-Pro (single-letter: MEHFPGP). Structurally the molecule is built from two recognizable parts:

• Met-Glu-His-Phe corresponds to the 4-7 fragment of adrenocorticotropic signalling factor. This tetrapeptide is the ACTH-derived portion that gives the compound its classification as an ACTH-fragment analog.
• Pro-Gly-Pro is a C-terminal proline-rich tripeptide appended to the ACTH fragment. In the published literature this proline-flanked terminus (with the central Gly residue) is described as a defining structural feature associated with the peptide’s reported resistance to exopeptidase cleavage.

Because the sequence contains three residues that are prone to isomeric or truncation-related variants (the two proline residues and the histidine), sequence-level confirmation is a central part of documenting an authentic sample rather than a related peptide impurity.

Appearance and physical characteristics

As a synthetic peptide, Semax is typically supplied as a white to off-white lyophilized (freeze-dried) powder. Peptides of this composition are generally soluble in water and in dilute aqueous solutions used for laboratory solution preparation with sterile water. As with other short peptides, samples are commonly stored cold and protected from repeated freezing and thawing to preserve sample integrity during handling for analytical work.

Analytical identity and purity testing

Confirming that a labeled sample is in fact Semax, and characterizing its purity, relies on orthogonal analytical methods:

• Mass spectrometry (LC-MS / HRMS): The measured monoisotopic or average mass is compared against the theoretical mass derived from C₃₇H₅₁N₉O₁₀S (813.93 g/mol). High-resolution mass spectrometry (HRMS) provides an accurate-mass match that supports identity confirmation and can flag mass-shifted impurities.
• High-performance liquid chromatography (HPLC): Reverse-phase HPLC estimates chromatographic purity as the area percentage of the main peak and resolves closely related peptide impurities. Method development balances gradient conditions and column chemistry to maximize separation performance for the target peak.
• Reading a Certificate of Analysis (COA): A COA typically reports the batch identifier, the identity method (for example LC-MS or HRMS), the analytical method used to estimate purity, and the measured purity value. Reviewing the batch number, the stated method and the reported purity together is how a researcher ties a physical vial to its documentation.

Every batch offered by Livvmore is identity- and purity-tested at the USC Alfred E. Mann Multi-Omics Mass Spectrometry Core, a university laboratory, using LC-MS and high-resolution mass spectrometry. The corresponding certificates are published in the COA library so that the analytical record for a given batch of Semax can be examined directly.

Research context

In the published scientific literature, Semax is studied as a synthetic model peptide within the ACTH-fragment analog family. Peer-reviewed work indexed on resources such as PubChem and PMC has examined this compound in the context of gene-expression and molecular-biology studies in laboratory models. These references are provided strictly as background on the compound’s place in the research record and describe experimental studies, not any application to people or animals.

For laboratory research use only. Not for human or veterinary use.

Frequently asked questions

What is the amino acid sequence of Semax?

Semax is a heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro (single-letter code MEHFPGP). The first four residues (Met-Glu-His-Phe) correspond to the 4-7 fragment of adrenocorticotropic signalling factor, and the C-terminal Pro-Gly-Pro tripeptide is appended to that fragment.

What is the molecular weight and molecular formula of Semax?

Semax has the molecular formula C37H51N9O10S and an average molecular weight of 813.93 g/mol. The sulfur atom in the formula comes from the N-terminal methionine residue. These values are recorded under PubChem CID 9811102.

What is the CAS number for Semax?

The CAS Registry Number for Semax is 80714-61-0. It corresponds to the synthetic ACTH(4-7) analog with a C-terminal Pro-Gly-Pro extension and is listed in public chemical databases including PubChem.

How is the identity of a Semax sample confirmed?

Identity is confirmed with orthogonal analytical methods. Liquid chromatography-mass spectrometry (LC-MS) and high-resolution mass spectrometry (HRMS) match the measured mass to the theoretical 813.93 g/mol, while reverse-phase HPLC estimates chromatographic purity from the main-peak area percentage. A Certificate of Analysis records the batch, the method used and the measured purity.

What does the Certificate of Analysis for Semax report?

A Certificate of Analysis typically lists the batch identifier, the identity method (such as LC-MS or HRMS), the purity method, and the measured purity value. Livvmore batches are tested at the USC Alfred E. Mann Multi-Omics Mass Spectrometry Core, and the certificates are published in the COA library so each batch can be traced to its analytical record.