3 4 diaminopyridine

Gambierol was synthesized as described by Fuwa et al. in 2002 [7 (link)] and had a purity >97%. The synthetic gambierol was spectroscopically (NMR ¹³C and ¹H, MS, IR) identical to natural gambierol. Due to the lipophilic nature of gambierol, stock solutions were prepared in dimethyl sulfoxide (DMSO) and diluted with the external physiological solution. The total DMSO concentration in the test solution did not exceed 0.1%. Tetrodotoxin, apamin, iberiotoxin, and glibenclamide were purchased from Alomone Labs (Jerusalem, Israel), and Latoxan (Portes-lès-Valence, France). All other chemicals, including cell culture media, reagents, tetraethylammonium chloride and 3,4-diaminopyridine, were purchased from Sigma-Aldrich (Saint-Quentin-Fallavier, France).

Aspirin (ASP), ibuprofen (IBU), nicotinamide (NC), isonicotinamide (INC), isoniazid (INZ), and methyl nicotinate (MN) were bought from Acros (Geel, Belgium). 3,4-diaminopyridine (AMI) was acquired from Sigma-Aldrich (St. Louis, MO, USA), 4-aminobenzoic acid (PABA) from Alfa Aesar (Haverhill, MA, USA), and zinc oxide from Merck (Kenilworth, NJ, USA). All the solvents and reagents were used as received without further treatment.