4-[7-(4-carbamimidoylphenoxy)heptoxy]benzenecarboximidamide

Kd: 6.9 μM (calcium-binding protein S100B)

Heptamidine is a Pentamidine-S100B complex, two molecules of pentamidine bind per monomer of S100B, which performs to be an inhibitor for S100B.Heptamidine (20 μM) does not decrease CUG levels significantly when compares to Propamidine and Pentamidine, and exhibits cytotoxic at concentrations above 17.5 μM in HeLa cells expressing 960 CUG repeats.Heptamidine rescues mis-splicing of minigene reporters in a HeLa cell DM1 model with an EC ₅₀ value of 15 μM.

Heptamidine (intraperitoneal injection; 20 or 30 mg/kg; 7 days) causes a dose-dependent reduction of exon 7a inclusion in HSA LR mice, returning to wild type levels (6±1%) when at 20 mg/kg dose, the myotonia is reduced from grade 3 to grade 1 (occasional myotonic discharge) or grade 0 at both 20 or 30 mg/kg.