80714-61-0
Semax
The unmodified Semax heptapeptide with free termini. Reference compound for the analogue series.
Typical release99.3%
From
£32.00
In stock
Neurological & CognitiveMost ordered
N-Acetyl Semax Amidate
AC-Semax-NH2 · NA-Semax-amidate · N-acetyl semax amidate · Ac-MEHFPGP-NH2
Terminally protected Semax analogue — N-acetylated, C-amidated. Released at ≥ 99.0% by RP-HPLC.
Total, ex VAT
£39.00
- Released at ≥ 99.0% (RP-HPLC, area %)
- Identity confirmed by ESI-MS against theoretical mass
- Batch certificate matched to the vial, verifiable online
- Same working day dispatch before 14:00, tracked
For laboratory research use only. Not for human or veterinary use, and not a medicine, food or cosmetic. Sold to qualified researchers and institutions who accept responsibility for safe handling and lawful use.
Compound data
What is in the vial
Indicative values for this line. The certificate issued with your batch is the authoritative record and reports the measured figures for the material you receive.
- CAS number
- 2920938-90-3
- Molecular formula
- C39H54N10O10S
- Average mass
- 855.0 g/mol
- Sequence
- Ac-Met-Glu-His-Phe-Pro-Gly-Pro-NH2
- Residues
- 7
- Class
- Terminally modified ACTH(4-7) analogue
- Form as supplied
- Lyophilised powder
- Appearance
- White lyophilised powder
- Purity specification
- ≥ 99.0% (RP-HPLC, area %)
- Solubility
- Soluble in sterile or bacteriostatic water. More lipophilic than unmodified Semax owing to terminal capping.
- Storage
- Lyophilised: −20 °C, desiccated and dark. Reconstituted: 2–8 °C.
Targets and pathways
- BDNF and NGF expression in neuronal preparations
- Monoamine turnover, dopaminergic and serotonergic
- Melanocortin-independent — no corticotropic activity
Overview
About N-Acetyl Semax Amidate
Semax is a synthetic heptapeptide built from the ACTH(4-7) fragment MEHF with a C-terminal Pro-Gly-Pro extension. That extension was the original stabilising trick: it blocks carboxypeptidase attack on a sequence that would otherwise be cleared in minutes. N-Acetyl Semax Amidate takes the same idea to both ends of the molecule, capping the N-terminus with an acetyl group and converting the C-terminal carboxyl to a primary amide.
Both modifications are protective rather than pharmacophoric. Acetylation blocks aminopeptidase cleavage, amidation blocks the carboxypeptidase route the Pro-Gly-Pro tail only partly defends, and together they neutralise the terminal charges — which changes the molecule's lipophilicity and, in turn, how it distributes in preparation. The result is a longer-lived analogue of a peptide whose principal research limitation was always its half-life.
Critically for interpretation, Semax and its analogues do not carry the corticotropic activity of the parent hormone. ACTH(4-7) lacks the residues required for melanocortin-2 receptor activation, so effects observed with this compound are studied as neurotrophic and neuromodulatory rather than as adrenal-axis effects. That separation is the reason the fragment was pursued at all.
In short
- N-terminal acetylation and C-terminal amidation on the Semax heptapeptide backbone
- Both modifications are protease-protective; neither is required for activity
- No corticotropic activity — the ACTH(4-7) fragment does not engage MC2R
- Released at ≥ 99.0% area-percent by RP-HPLC, identity confirmed by ESI-MS
- Supplied lyophilised; contains one oxidation-sensitive methionine
Where it is used
Research applications
Neurotrophin expression
The most consistently reported effect of the Semax family in neuronal preparations is upregulation of BDNF and NGF and of their receptor transcripts, which is the basis of most neuroprotection work with the compound.
Terminal modification and stability
Because the parent, the Pro-Gly-Pro-extended form and the doubly capped analogue are all available, the series is a clean model system for studying how terminal protection changes peptide half-life and distribution without changing the pharmacophore.
Monoamine systems
The peptide is used in studies of dopaminergic and serotonergic turnover, where its melanocortin-independence removes a confound present with longer ACTH fragments.
Ischaemia and hypoxia models
Semax has an extensive Russian-language literature in cerebral ischaemia models, and the stabilised analogue appears increasingly in that work where longer exposure is wanted.
Transcriptomic response
Microarray and RNA-seq studies of Semax exposure report broad changes in neuroinflammatory and vascular gene sets, and are used to map the compound's effects beyond neurotrophins alone.
Handling
Reconstitution and stability
Reconstitution
Add diluent slowly against the vial wall and allow the powder to dissolve without agitation. The capped termini make this analogue slightly more lipophilic than unmodified Semax; if dissolution is slow, extend the standing time rather than warming or vortexing the vial.
Stability
Lyophilised at −20 °C, desiccated and dark, material is stable for at least 24 months. Reconstituted and held at 2–8 °C, use within 21 days. The single methionine is oxidation-sensitive, so minimise headspace and air exposure in the working vial.
Notes
- Terminal capping means this compound is not interchangeable with unmodified Semax in a method. Retention time, mass and often solubility all differ — re-qualify your assay when switching.
- Confirm which analogue a published protocol used. Semax, Semax amidate and N-acetyl Semax amidate are distinct compounds and are frequently conflated in secondary sources.
- The methionine oxidises to the sulfoxide on air exposure; expect a small early-eluting peak to grow in an ageing solution.
- Adsorption to plastic is modest but real at low concentrations. Use glass or low-binding plasticware for dilute working solutions.
Laboratory reference
Reconstitution calculator
Enter the fill weight on the vial and the diluent volume you intend to add. The calculator returns the resulting solution concentration and the volume that contains a given mass.
- Concentration
- 5.000 mg/mL · 5000 µg/mL
- Volume containing target mass
- 50.0 µL · 0.0500 mL
Figures are mass-to-volume arithmetic for laboratory preparation of N-Acetyl Semax Amidate and take no account of net peptide content, which is stated on the batch certificate and should be applied to the fill weight before calculating. Nothing here constitutes dosing, administration or clinical guidance of any kind.
Published work
What the literature reports
Summaries of published findings, provided as research reference. These describe work done by others in preclinical and clinical settings; they are not claims about this material or outcomes for any reader.
Neurotrophin induction
Studies in rat hippocampal preparations reported increased BDNF protein and transcript following Semax exposure, establishing the neurotrophic mechanism that underlies most subsequent work on the family.
Dolotov et al., Journal of Neuroscience Research, 2006
Transcriptome response in ischaemia
Genome-wide expression analysis in a rat focal ischaemia model reported Semax-associated changes across immune and vascular gene sets, broadening the mechanistic picture beyond neurotrophins.
Medvedeva et al., Journal of Molecular Neuroscience, 2014
ACTH fragment structure–activity
Work separating the behavioural and neurotrophic activity of short ACTH fragments from adrenal stimulation established that ACTH(4-7)-derived peptides act without corticotropic effect.
Ashmarin et al., Neuroscience and Behavioral Physiology
Terminal modification and protease resistance
General peptide chemistry establishing that N-acetylation and C-amidation confer resistance to amino- and carboxypeptidase cleavage respectively, which is the design rationale for this analogue.
Reviewed in Werle & Bernkop-Schnürch, Amino Acids, 2006
Questions
N-Acetyl Semax Amidate — asked and answered
Something not covered here? Ask us directly — technical questions reach someone who runs the assays.
- How does this differ from ordinary Semax?
- Semax is H-Met-Glu-His-Phe-Pro-Gly-Pro-OH with free termini. This analogue caps both: an acetyl group on the N-terminus and a primary amide at the C-terminus. The pharmacophore is unchanged; the modifications block aminopeptidase and carboxypeptidase cleavage and increase lipophilicity. They are different compounds with different masses and retention times.
- Is AC-Semax-NH2 the same product?
- Yes. AC-Semax-NH2, NA-Semax-amidate and N-acetyl semax amidate all denote the same compound, Ac-MEHFPGP-NH2, CAS 2920938-90-3. The naming is inconsistent across suppliers and literature, which is why we state the full modified sequence on the certificate rather than relying on a trade name.
- Does it have corticotropic activity?
- No. The ACTH(4-7) fragment lacks the residues needed to activate the melanocortin-2 receptor, which is precisely why this fragment was developed. Effects are studied as neurotrophic and neuromodulatory rather than adrenal.
- What is the shelf life once reconstituted?
- 21 days at 2–8 °C. The limiting factor is oxidation of the single methionine residue rather than backbone hydrolysis, so minimising air exposure matters more than temperature within that range.
- Can I use a published Semax protocol directly?
- Not without re-qualifying it. Mass, retention time and solubility all differ from the unmodified peptide, so concentration calculations and analytical methods both need checking. Confirm which analogue the original work used before transferring anything.
Same class
Others in Neurological & Cognitive
Important
N-Acetyl Semax Amidate is supplied strictly for laboratory research and analytical use. It is not a medicine, food, cosmetic or veterinary product; it is not for human or animal consumption; and it is not intended to diagnose, treat, cure or prevent any condition. It is not manufactured, tested or released to any standard that would support administration to humans or animals. Information on this page is compiled for research reference and is not medical advice. No dosing, administration or therapeutic guidance is given or implied. By ordering you confirm you are a qualified researcher or institution and accept responsibility for safe handling and lawful use.