N-Acetyl Semax
Also known as Acetyl-Semax, N-Acetyl Semax amidate
N-Acetyl Semax is the N-terminally acetylated form of Semax — a terminal stability modification. A research-use profile centered on the acetylation and its handling implications.
Like its Selank counterpart, this compound is defined by a single edit at the end of the chain rather than by a new sequence. Semax — the ACTH(4-10)-derived heptapeptide covered on its own page — has a methionine at its N-terminus. Acetylate the amine on that first residue and you have N-Acetyl Semax.
The rationale is the familiar one for terminal acetylation: the exposed N-terminal amine is a preferred entry point for aminopeptidases, and capping it with an acetyl group is a common way to modify how a short peptide resists trimming from that end. Here the modification is also notable because it sits next to methionine, a residue with its own chemistry — which is part of why acetyl-Semax is treated as a distinct material worth its own certificate.
The parent's sequence, its ACTH-fragment origin, and its research contexts live on the Semax monograph. This page is about what changes when the terminus is acetylated.
N-Acetyl Semax is Semax bearing an acetyl group (CH3CO-) on its N-terminal methionine amine. The cap neutralizes the free alpha-amino group at the start of the chain — a deliberate modification aimed at the terminus, adjacent to the reactive methionine residue.
The acetylation, specifically at the N-terminal methionine
Semax begins with Met-Glu-His-Phe, so N-terminal acetylation caps the amine of that leading methionine. Converting the charged free amino terminus into a neutral acetyl-capped one is a standard strategy for reducing N-side exopeptidase cleavage, and it leaves the internal ACTH-derived core and the Pro-Gly-Pro tail intact.
In other words the melanocortin-fragment signature that defines Semax is preserved; the acetyl group changes the front of the molecule, not its identity. This is a stability-and-handling modification, not a different peptide family.
Cataloguing and certificate differences
Because the acetyl group adds mass and can alter chromatographic retention, acetyl-Semax and plain Semax are listed as separate research materials with separate certificates. A certificate of analysis for this compound should explicitly note N-terminal acetylation and should not read identically to unmodified Semax.
When comparing the two, the acetyl-attributable mass shift is the practical identifier. Verify the batch number and that the stated structure specifies the N-terminal cap.
These are research areas the compound is associated with in the literature — not medical claims or intended uses.
Handling & storage
Supplied lyophilized. Stored sealed and cold; reconstituted with bacteriostatic water only when a protocol requires it, then kept refrigerated. Handle per accepted laboratory practice.
Verify a certificate by lot →Common questions
It is the same ACTH-fragment-derived heptapeptide with an acetyl group capping the N-terminal methionine amine. The edit is at the terminus; the core sequence is unchanged.
The free N-terminal amine is a common site for aminopeptidase cleavage. Acetylation caps it — a routine peptide-chemistry modification for changing a peptide's degradation and stability behavior.
No. The acetyl group changes the mass and can shift HPLC retention, so a valid certificate specifies N-terminal acetylation rather than matching unmodified Semax.
This monograph is a research-use reference. It describes composition and the contexts in which the compound has been studied — it is not medical advice, a description of effects, or a recommendation for use. Sold strictly for laboratory and research use; not for human or animal consumption.