NA-Semax
What is NA-Semax?
N-Acetyl Semax (known chemically as ACTH 4-7-PGP or Met-Glu-His-Phe-Pro-Gly-Pro) is a synthetic heptapeptide developed by the Institute of Molecular Genetics of the Russian Academy of Sciences. Engineered as an analog of the adrenocorticotropic hormone fragment (α-ACTH4-10), Semax incorporates a C-terminal Pro-Gly-Pro (PGP) tripeptide sequence. This structural modification completely eliminates systemic hormonal activity while dramatically extending the peptide’s metabolic lifespan and central nervous system bioavailability. Researchers investigate Semax for its pronounced nootropic, neuroprotective, and neurorestorative properties, particularly its ability to enhance executive cognitive focus, stimulate trophic factor expression, and shield cerebral tissues from ischemic and oxidative stress.
For laboratory and in vitro evaluation, researchers often choose to buy Semax in high-purity lyophilized powder or nasal spray reference formats. Reconstituted solutions can be securely prepared using sterile laboratory buffers or a specialized reconstitution solution to ensure structural stability and prevent premature enzymatic breakdown during experimental screening protocols.
Chemical and Molecular Data
| Compound Name | NA-Semax |
|---|---|
| Quantity / Formats | 5MG / 10MG / Nasal Reference Formats |
| Synonyms / Alt Names | ACTH (4-7), Pro-Gly-Pro-; ACTH (4-7), prolyl-glycyl-proline-; Pro-gly-pro-acth (4-7) |
| CAS Number | 80714-61-0 |
| Chemical Formula | C37H51N9O10S |
| Molecular Weight | 813.9 g/mol |
| IUPAC Name | (2S)-1-[2-[[(2S)-1-[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-amino-4-methylsulfanylbutanoyl]amino]-4-carboxybutanoyl]amino]-3-(1H-imidazol-5-yl)propanoyl]amino]-3-phenylpropanoyl]pyrrolidine-2-carbonyl]amino]acetyl]pyrrolidine-2-carboxylic acid |
| InChIKey | AFEHBIGDWIGTEH-AQRCPPRCSA-N |
| SMILES Code | CSCC[C@@H](C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](CC1=CN=CN1)C(=O)N[C@@H](CC2=CC=CC=C2)C(=O)N3CCC[C@H]3C(=O)NCC(=O)N4CCC[C@H]4C(=O)O)N |
What are the Mechanisms of Action?
The biochemical pathways and cellular targets of Semax include:
- BDNF & TrkB Signaling Pathway Activation: Research demonstrates that Semax rapidly upregulates the gene expression and protein synthesis of Brain-Derived Neurotrophic Factor (BDNF) and its primary receptor, tropomyosin receptor kinase B (TrkB), in the basal forebrain and hippocampus. This trophic factor activation promotes neuronal survival, synaptic plasticity, and dendritic branching.
- Monoaminergic & Cholinergic Modulation: In addition to neurotrophin induction, Semax modulates central monoamine metabolism, stimulating dopamine release and accelerating serotonin turnover rates in the cerebral cortex. It also activates choline acetyltransferase activity, enhancing cholinergic signaling required for acute attention and memory consolidation.
- Vascular & Immune Transcriptome Regulation: Studies indicate that during ischemic stress, Semax alters the expression of genes governing vascular development, cell migration, and immune modulation. It suppresses inflammatory cytokine transcripts (e.g., IL-1α, IL-1β, IL-6, TNF-α) while preserving endothelial integrity and local microvascular circulation.
What are the Clinical & Preclinical Trials on Semax?
When evaluating research efficacy and published experimental literature for Semax:
- Transcriptome Analysis in Focal Ischemia Models: Landmark genome-wide studies indexed in PMC (PMC3987924) evaluated rat brain cortex tissues following middle cerebral artery occlusion. The data revealed that Semax significantly modulates over 50% of immune- and vascular-related genes altered during ischemic events, suppressing pro-inflammatory pathways and accelerating vasculogenesis markers to preserve neuronal tissue.
- Inhibition of Copper-Induced Amyloid Aggregation: Spectrofluorometric and calorimetric research published in ACS Chemical Neuroscience evaluated Semax’s interaction with metal ions. Results confirmed that Semax forms stable coordination complexes with Cu2+ ions, preventing the formation of toxic Aβ:Cu2+ complexes and inhibiting copper-induced amyloid-β fibrillogenesis in artificial membrane models.
- Trophic Factor Expression & Neuroprotection: Preclinical investigations detailed in ScienceDirect (Brain Research) demonstrated that Semax administration induces a sustained increase in BDNF and nerve growth factor (NGF) mRNA levels in rat basal forebrain structures, directly protecting cholinergic neurons from oxidative damage and glutamate excitotoxicity.
How does Semax compare to other compounds?
To evaluate chemical stability, blood-brain barrier permeability, and functional profiles, researchers compare native Semax against its acetylated, amidated, and adamantalated derivatives, as well as its sister neuropeptide Selank:
| Compound / Variant | Primary Mechanism / Modification | Chemical Stability & Permeability | Biological Focus & Research Profile |
|---|---|---|---|
| Semax | Unmodified heptapeptide sequence (Met-Glu-His-Phe-Pro-Gly-Pro) | Standard peptide stability enhanced by the C-terminal PGP sequence | Core benchmark for cognitive focus, executive mental clarity, stroke recovery models, and neuroprotection |
| NA-Semax (N-Acetyl Semax) | Addition of an N-terminal acetyl group | Increased lipophilicity and improved mucosal membrane penetration | Enhanced resistance to N-terminal peptidases, yielding a longer biological half-life and greater systemic absorption per dose |
| NA-Semax-Amidate | N-terminal acetylation paired with C-terminal amidation (-NH2) | Dual-end capped structure offering maximum resistance to both aminopeptidases and carboxypeptidases | Highest enzymatic stability among standard analogs; exhibits prolonged central activity and elevated potency at lower research concentrations |
| Adamax | N-Acetyl Semax modified with an adamantane moiety at the C-terminus | Extreme lipophilicity allowing rapid blood-brain barrier penetration and cellular accumulation | Engineered for high central potency and extended half-life; strongly amplifies BDNF expression and neuroplasticity cascades in advanced models |
| Selank | Synthetic tuftsin derivative targeting GABAA receptors and enkephalinase enzymes | Stabilized heptapeptide structure incorporating a C-terminal PGP modification | Primary focus on non-sedating anxiolysis, stress mitigation, and immunomodulation, contrasting with Semax’s executive stimulant/focus profile |
Frequently Asked Questions (FAQs)
1. What is the structural origin of Semax?
Semax is a synthetic heptapeptide derived from the adrenocorticotropic hormone fragment ACTH(4-10). It combines the active ACTH amino acid sequence (Met-Glu-His-Phe) with a C-terminal tripeptide sequence (Pro-Gly-Pro).
2. How does the Pro-Gly-Pro (PGP) tripeptide addition affect Semax stability?
The addition of the PGP sequence at the C-terminus protects the peptide from rapid enzymatic degradation by carboxypeptidases in blood plasma and biological tissues, extending its functional half-life compared to native ACTH fragments.
3. Does Semax exhibit hormonal activity like full-length ACTH?
No. By isolating the 4-7 fragment and appending the PGP tripeptide, Semax completely eliminates systemic endocrine activity, meaning it does not stimulate adrenal steroidogenesis or elevate systemic cortisol levels.
4. How do N-acetylated and amidated variants (NA-Semax, NA-Semax-Amidate, Adamax) differ from native Semax?
Modifications such as N-terminal acetylation, C-terminal amidation, or adamantane capping shield the terminal ends of the peptide from proteolytic enzymes. These structural changes increase lipophilicity and blood-brain barrier permeability, resulting in enhanced metabolic stability and prolonged central nervous system activity.
5. What storage conditions are required for Semax in laboratory settings?
Lyophilized Semax powder should be stored sealed at -20°C for long-term preservation. Once reconstituted with a sterile solution or specialized laboratory buffer, the liquid compound must be kept refrigerated at 2°C to 8°C and protected from light to prevent thermal degradation.
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Certificate of Analysis
Certificates of analysis are provided for laboratory research reference. Expand a batch below to view the PDF. Only the newest three COAs for this product are listed here.
NA-SEMAX 10MG - Lot / Batch: BX-P-Z1W9
- Mass Identification: N-Acetyl Semax, Confirmed
- Average Net Peptide: 13.71 mg
- Average Purity: 99.08%
- Endotoxin Threshold Results: Pass (Assay sensitivity ≤0.05 EU/mL; Replicate 1: Pass, Replicate 2: Pass)
- Lot#: BX-P-Z1W9
- Search Code: esse2608060905
Search all COAs by batch number (includes older batches not shown above).
