Synthesis and preliminary evaluation of hydroquinone-substituted histidine derivatives as putative histaminergic neurotoxins
摘要:
A series of hydroquinone-substituted histidine derivatives were synthesized as potential histaminergic neurotoxins. The compounds undergo autoxidation at physiologic pH as exemplified by 2-amino-3-[2-4,5,-trihydroxyphenyl)imidazo-4-yl]propionic acid 11. One of the synthesized histidine derivatives, namely 2-amino-3-[2-(2,3-dihydroxyphenyl)imidazo-4-yl]propionic acid 8, was tested for its degenerating effect on histaminergic, dopaminergic and serotonergic neurons in rat brain. After 4 d of an unilateral injection of 1 mu l 3 mM 8 in 0.1 M phosphate buffer (pH 7.4) into the posterior hypothalamus, a decrease in immunoreactivity in the presumable histaminergic neurons was observed whilst dopaminergic and serotonergic neuronal elements were little affected. A possible mechanism of action is discussed.
2-Phenyl-4-(aminomethyl)imidazoles as Potential Antipsychotic Agents. Synthesis and Dopamine D2 Receptor Binding
摘要:
A series of 2-phenyl-4-(aminomethyl)imidazoles were designed as conformationally restricted analogs of the dopamine D-2 selective benzamide antipsychotics. The title compounds were synthesized and tested for blockade of[H-3]YM-09151 binding in cloned African green monkey dopamine D-2 receptor preparations. The binding affinity data thus obtained were compared against that of the benzamides and a previously described series of 2-phenyl-5-(aminomethyl)-pyrroles.