Analogues of γ-hydroxybutyric acid. Synthesis and binding studies

Article abstract of DOI:10.1021/jm00400a001

Substituted 4-hydroxybutyric (GHB) or trans-4-hydroxycrotonic acids (T-HCA) and structurally related compounds were synthesized and submitted to [³H]GHB binding. Structure-activity relationship studies highlighted for [³H]GHB binding (a) the necessity of a nonlactonic, relatively extended conformation of the γ-hydroxybutyric chain, (b) the existence of some bulk tolerance in the vicinity of the hydroxyl group, and (c) the high sensitivity toward isosteric replacement of the carboxyl or the hydroxyl groups. T-HCA has been recently identified as a naturally occurring substance in the central nervous system (CNS) and shows a better affinity than GHB. Our findings are in favor of the presence in the CNS of specific GHB binding sites, which are different from the GABA and the picrotoxin binding sites, and for which T-HCA may be an endogenous ligand.