Omeprazole and talampanel as two examples of retrometabolic drug design.

The goal of retrometabolic drug design is: "to design safe, locally active compounds with an improved therapeutic index". Here we describe two cases from our own practice, talampanel and omeprazole.

New non competitive AMPA antagonists.

New halogen atom substituted 2,3-benzodiazepine derivatives condensed with an azole ring on the seven membered part of the ring system of type 3 and 4 as well as 5 and 6 were synthesized. It was found that chloro-, dichloro- and bromo-substitutions in the benzene ring and additionally imidazole ring condensation on the diazepine ring can successfully substitute the methylenedioxy group in the well known molecules GYKI 52466 (1) and GYKI 53773 (2) and the 3-acetyl-4-methyl structural feature in 2, respectively, preserving the highly active AMPA antagonist characteristic of the original molecules. From the most active compounds (3b,i) 3b (GYKI 47261) was chosen for detailed investigations.

Structural analogues of some highly active non-competitive AMPA antagonists.

Some 5-methyl analogues (14a-e) of the non-competitive AMPA antagonists 3-acylated 1-(4-aminophenyl)-4-methyl-7,8-methylenedioxy-4,5-dihydro-3H-2,3-benzodi azepines (2,3) have been synthesized. Generally they show diminished or low biological activity but two derivatives (14a,b) reveal effects comparable to those of GYKI 52466 (1), the prototype non competitive AMPA antagonist.

Anxiolytic 2,3-benzodiazepines, their specific binding to the basal ganglia.

Over the past 20 years, several members of the 2,3-benzodiazepine family have been synthesized. Some of these compounds--tofisopam (Grandaxin), girisopam, nerisopam--exert significant anxiolytic and antipsychotic activities. Sites where actions of 2,3-benzodiazepines are mediated differ from those of 1,4-benzodiazepines.

Anxiolytic profile of girisopam and GYKI 52,322 (EGIS 6775). Comparison with chlordiazepoxide and buspirone.

The anxiolytic action of two 2,3-benzodiazepines: girisopam: GYKI 51,189 (EGIS 5810): (1-(3-chlorophenyl)-4-methyl-7,8-dimethoxy-5H-2,3-benzodiazepine), and GYKI 52,322 (EGIS 6775): (1-(4-aminophenyl)-4-methyl-7,8-dimethoxy-5H-2,3-benzodiazepine) was investigated in comparison to chlordiazepoxide and buspirone using three different animal models of anxiety: the lick conflict, the elevated plus maze and the open field methods in rats. Both 2,3-benzodiazepines exerted anxiolytic effect in all three tests used, however their pharmacological profile differs considerably from that of either chlordiazepoxide or buspirone. Using the animal models mentioned above the order of potency was GYKI 52,322 (EGIS 6775) > chlordiazepoxide > girisopam > buspirone.