(alpha S)-erythro-alpha-methylepinephrine: preparation and stereoselective binding to adrenergic receptors in rat forebrain.
The enantiomers of a number of catecholamines, including (alpha S)- and (alpha R)-erythro-alpha-methylepinephrine, were evaluated for their capacity to compete for binding sites in rat forebrain homogenates with [3H]prazosin, a ligand which selectively binds to adrenergic receptors of the alpha 1 subtype. (alpha R)-erythro-alpha-Methylepinephrine is devoid of apparent biological activity, but the activity of the alpha S isomer is substantial. The latter is less active than the endogeneous catecholamines, (R)-norepinephrine and (R)-epinephrine, but the stereospecific competition for [3H]prazosin binding sites by the catecholamine isomers with the beta R configuration is additional evidence that (alpha S)-erythro-alpha-methylepinephrine may be a biologically active metabolite of L-alpha-methyl-3,4-dihydroxyphenylalanine.
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002395:Catecholamines / Q000138:chemical synthesis* / Q000378:metabolism; D002942:Circular Dichroism; D004837:Epinephrine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000378:metabolism; D011224:Prazosin / Q000378:metabolism; D051381:Rats; D011941:Receptors, Adrenergic / Q000378:metabolism*; D013237:Stereoisomerism
D002395:Catecholamines; D011941:Receptors, Adrenergic; C029205:alpha-methylepinephrine; D011224:Prazosin; D004837:Epinephrine