N-Acetyl Semax Amidate

N-Acetyl Semax Amidate is a synthetic heptapeptide derivative of semax (Met-Glu-His-Phe-Pro-Gly-Pro) with an acetyl group on the N-terminal amine and an amide in place of the C-terminal carboxyl group. Its molecular formula, C39H54N10O10S (molecular weight 855.0 g/mol, CAS 2920938-90-3), differs from that of semax (C37H51N9O10S) by C2H3N, which matches the addition of an acetyl cap and the conversion of the terminal acid to an amide. The parent peptide combines the ACTH(4-7) fragment with a C-terminal Pro-Gly-Pro tripeptide.

N-Acetyl Semax Amidate in the research literature

Few published studies address the modified forms directly. A coordination-chemistry study of N-terminally acetylated semax (Ac-Semax, without the C-terminal amide) reported that acetylation changed the main copper(II) complex from a CuN4 to a distorted CuN3O chromophore and shifted its redox potential, while zinc(II) complexes formed with strength comparable to the parent. In SH-SY5Y cell cultures, the free N-terminal amine was reported to be needed for the parent peptide's activity against copper(II)-induced toxicity.

The rest of the relevant literature concerns unmodified semax. Rat studies have linked it to hippocampal BDNF and TrkB expression. Transcriptome work in rat middle cerebral artery occlusion models reported shifts in inflammation-related and neurotransmission-related gene expression. In degradation studies with nerve cells, the parent peptide was cleaved mainly to His-Phe-Pro-Gly-Pro and Pro-Gly-Pro.