Synthesis and structure-activity relationships of a new model of arylpiperazines. 5. Study of the physicochemical influence of the pharmacophore on 5-HT(1a)/alpha(1)-adrenergic receptor affinity: synthesis of a new derivative with mixed 5-HT(1a)/d(2) antagonist properties.
In this paper we have designed and synthesized a test series of 32 amide arylpiperazine derivatives VI in order to gain insight into the physicochemical influence of the pharmacophores of 5-HT(1A) and alpha(1)-adrenergic receptors. The training set was designed applying a fractional factorial design using six physicochemical descriptors. The amide moiety is a bicyclohydantoin or a diketopiperazine (X = -(CH(2))(3)-, -(CH(2))(4)-; m = 0, 1), the spacer length is 3 or 4 methylene units, which are the optimum values for both receptors, and the aromatic substituent R occupies the ortho- or meta-position and has been selected from a database of 387 substituents using the EDISFAR program. The 5-HT(1A) and alpha(1)-adrenergic receptor binding affinities of synthesized compounds VI (1-32) have been determined. This data set has been used to derive classical quantitative structure-activity relationships (QSAR) and neural networks models for both receptors (following paper). A comparison of these models gives information for the design of the new ligand EF-7412 (46) (5-HT(1A): K(i) = 27 nM; alpha(1): K(i) > 1000 nM). This derivative displays affinity for the dopamine D(2) receptor (K(i) = 22 nM) and is selective versus all other receptors examined (5-HT(2A), 5-HT(3), 5-HT(4) and Bz; K(i) > 1000 nM). EF-7412 (46) acts as an antagonist in vivo in pre- and postsynaptic 5-HT(1A) receptor sites and as an antagonist in the dopamine D(2) receptor. Thus, EF-7412 (46) is a derivative with mixed 5-HT(1A)/D(2) antagonist properties and this derivative could be useful as a pharmacological tool.
López-Rodríguez
M L
ML
Departamento de Química Orgánica I, Facultad de Ciencias Químicas, and Departamento de Farmacología, Facultad de Farmacia, Universidad Complutense, 28040 Madrid, Spain. mluzlr@eucmax.sim.ucm.es
Morcillo
M J
MJ
Fernández
E
E
Porras
E
E
Orensanz
L
L
Beneytez
M E
ME
Manzanares
J
J
Fuentes
J A
JA
D000818:Animals; D001667:Binding, Competitive; D001831:Body Temperature / Q000187:drug effects; D001921:Brain / Q000378:metabolism; D020650:Combinatorial Chemistry Techniques; D003345:Corticosterone / Q000097:blood; D018492:Dopamine Antagonists / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D010879:Piperazines / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D011187:Posture; D011863:Radioimmunoassay; D011869:Radioligand Assay; D051381:Rats; D017207:Rats, Sprague-Dawley; D018340:Receptors, Adrenergic, alpha-1 / Q000378:metabolism*; D017448:Receptors, Dopamine D2 / Q000187:drug effects*; D011985:Receptors, Serotonin / Q000187:drug effects*; D044263:Receptors, Serotonin, 5-HT1; D012702:Serotonin Antagonists / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013449:Sulfonamides / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology
D018492:Dopamine Antagonists; D010879:Piperazines; D018340:Receptors, Adrenergic, alpha-1; D017448:Receptors, Dopamine D2; D011985:Receptors, Serotonin; D044263:Receptors, Serotonin, 5-HT1; D012702:Serotonin Antagonists; D013449:Sulfonamides; C120936:EF 7412; D003345:Corticosterone