Semax

Semex is a synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) derived from the adrenocorticotropic hormone ACTH(4-10) fragment. It was developed in Russia in the 1980s and 1990s as a derivative of ACTH, with the goal of creating a peptide that possessed neuroprotective and cognitive-enhancing properties without the endocrine side effects of the parent hormone. The synthetic peptide consists of the ACTH(4-7) core (Met-Glu-His-Phe), which retains the neurotropic activity of ACTH but lacks corticotropic activity, and a C-terminal Pro-Gly-Pro (PGP) extension that acts as a metabolic "shield" against peptidases, significantly extending its half-life in plasma and cerebrospinal fluid. The compound is classified as a nootropic and neuroprotective agent with demonstrated anxiolytic and antidepressant properties.

Semex exerts its effects through multiple interconnected mechanisms. It acts as a modulator of the melanocortin system, potentially interacting with MC4R and MC5R receptors. A key mechanism is the rapid and potent upregulation of brain-derived neurotrophic factor (BDNF) and its high-affinity receptor TrkB. This upregulation is driven by intracellular signaling cascades, including the cAMP-PKA-CREB pathway, which promotes transcription of the Bdnf gene. Semex also regulates cortical nitric oxide (NO) production, sequesters copper ions, and interacts directly with Aβ:Cu²⁺ oligomers, leading to reduced amyloid β protein aggregation.

• Ischemic Stroke and Neuroprotection: Investigated for its pronounced neuroprotective effects in the treatment of cerebrovascular insufficiency and acute cerebral stroke.
• Cognitive Enhancement and Nootropic Studies: Employed in research to evaluate its positive influence on memory, learning, attention, and cognitive function.
• Anxiety and Mood Research: Studied for its anxiolytic and antidepressant effects, with demonstrated ability to reduce anxiety-like behavior and normalize levels of brain biogenic amines.
• Neurodegenerative Disease Models: Used in preclinical models to investigate its potential to reduce amyloid β aggregation and fibrillogenesis, with relevance to Alzheimer's disease research.

CAS Number: 80714-61-0 (free base); 2828433-33-4 (acetate salt)
PubChem CID: 9811102
Molecular Formula: C₃₇H₅₁N₉O₁₀S
Molecular Weight: 813.92 g/mol
Sequence: Met-Glu-His-Phe-Pro-Gly-Pro (MEHFPGP)
Purity: ≥ 98% (batch-dependent; refer to Certificate of Analysis)
Form: White to off-white lyophilized powder
Storage: Store at ≤ -20°C in a cool, dry place, protected from light and moisture
Solubility: Soluble in sterile water, PBS (pH 7.2), and DMSO; prepare working solutions per laboratory protocol