CO-102862

During the last fifteen years, semicarbazones have been extensively investigated for their anticonvulsant properties. 4-(4-Flurophenoxy) benzaldehyde semicarbazone (C0102862, V102862) was discovered as a lead molecule and is being developed as a potent antiepileptic drug, with maximal electroshock (MES) ED50 of i.p. 12.9 mg kg-1. In MES (oral screen), this compound has a protective index (PI = TD50/ED50 > 315) higher than carbamazepine (PI 101), phenytoin (PI > 21.6) and valproate (PI 2.17). The compound is a potent sodium channel blocker. Other semicarbazones have demonstrated activity in various chemoshock screens, like subcutaneous pentylenetetrazole, subcutaneous strychnine, subcutaneous picrotoxin and subcutaneous bicculine. Semicarbazones are also GABA-transaminase inhibitors. Extensive structure- -activity relationship has demonstrated that F, Cl, Br and NO2 substituents in the arylhydrophobic pocket and a hydrogen bonding domain (HBD) are generally found in active anticonvulsant agents.

A quantitative-structure activity relationship (QSAR) study has been made on two different series of sodium channel blockers--namely, a series of 3-(4-phenoxyphenyl)pyrazoles and a series of 2-alkyl-4-arylimidazoles--and a series of potassium channel blockers that comprises of khellinone derivatives, which act on voltage-gated K(+) channels Kv1.3. In both the cases--the inhibition of Na+ channels or the inhibition of K+ channels--the significant correlations were obtained between the inhibition potencies and the hydrophobic properties of the compounds. This led to suggest that the hydrophobic property of the compounds is a major determining factor of the Na+/K+ channel blocking activity and that the compounds might elicit their effects through the hydrophobic interactions with the receptors.