title: N-(4-(4-(2,3-dichloro- or 2-methoxyphenyl)piperazin-1-yl)butyl)heterobiarylcarboxamides with functionalized linking chains as high affinity and enantioselective D3 receptor antagonists.
abstract: In the present report, the D3 receptor pharmacophore is modified in the 2,3-diCl- and 2-OCH(3)-phenylpiperazine class of compounds with the goal to improve D3 receptor affinity and selectivity. This extension of structure-activity relationships (SAR) has resulted in the identification of the first enantioselective D3 antagonists (R- and S-22) to be reported, wherein enantioselectivity is more pronounced at D3 than at D2, and that a binding region on the second extracellular loop (E2) may play a role in both enantioselectivity and D3 receptor selectivity. Moreover, we have discovered some of the most D3-selective compounds reported to date that show high affinity (K(i) = 1 nM) for D3 and approximately 400-fold selectivity over the D2 receptor subtype. Several of these analogues showed exquisite selectivity for D3 receptors over >60 other receptors, further underscoring their value as in vivo research tools. These lead compounds also have appropriate physical characteristics for in vivo exploration and therefore will be useful in determining how intrinsic activity at D3 receptors tested in vitro is related to behaviors in animal models of addiction and other neuropsychiatric disorders.
authors.affiliation: Medicinal Chemistry Section, National Institute on Drug AbuseIntramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, USA. anewman@intra.nida.nih.gov
authors.forename: Amy Hauck
authors.initials: AH
authors.lastname: Newman
authors.forename: Peter
authors.initials: P
authors.lastname: Grundt
authors.forename: George
authors.initials: G
authors.lastname: Cyriac
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Deschamps
authors.forename: Michelle
authors.initials: M
authors.lastname: Taylor
authors.forename: Rakesh
authors.initials: R
authors.lastname: Kumar
authors.forename: David
authors.initials: D
authors.lastname: Ho
authors.forename: Robert R
authors.initials: RR
authors.lastname: Luedtke