[Design of the novel dipeptide neuropsychotropic drug preparations]

Abstract

The paper considers a new strategy in the field of neuropsychotropic dipeptide drug design, the main points being as follows: (i) determination of the structural elements of dipeptides, such as fragments of amino acid side radicals and peptide bonds, in nonpeptide drugs; (ii) design of peptide analogs topologically close to the drug; (iii) synthesis and activity testing of these analogs; (iv) determination of the corresponding endogenous neuropeptide among the known neuropeptides or identification of the new neuropeptides in the brain of experimental animals. Using this approach, new pyroglutamyl- and prolyl-containing dipeptides were obtained based on the structure of the well-known classical nootropic drug piracetam. The new drugs exhibit nootropic activity in doses 100-10,000 times lower than those of piracetam. The structure of most active pyroglutamyl dipeptide pGlu-Asn-NH2 coincides with that of the N-end fragment of the endogenous memory peptide AVP(4-9). Noopept (N-phenylacetylprolylglycine ethyl ester), patented in Russia and USA as a new nootropic drug, is currently under stage 2 of successful clinical trials. The main metabolite of noopept, cyclo-Pro-Gly, is identical to the endogenous dipeptide designed in this work and is most close analog of piracetam with respect to pharmacological activity. The universal character of the proposed strategy is demonstrated by the design of active dipeptide analogs of an atypical neuroleptic drug sulpiride. As a result, a potential dipeptide neuroleptic dilept was obtained, which has been patented in Russia and now passes broad preclinical trials.