Synthesis and in Vitro Activity of 3β-Substituted-3α-hydroxypregnan-20-ones: Allosteric Modulators of the GABAA Receptor
摘要:
Two naturally occurring metabolites of progesterone, 3 alpha-hydroxy-5 alpha- and 5 beta-pregnan-20-one (1 and 2), are potent allosteric modulators of the GABA(A) receptor. Their therapeutic potential as anxiolytics, anticonvulsants, and sedative/hypnotics is limited by rapid metabolism. To avoid these shortcomings, a series of 3 beta-substituted derivatives of 1 and 2 was prepared. Small lipophilic groups generally maintain potency in both the 5 alpha- and 5 beta-series as determined by inhibition of [S-35]TBPS binding. In the 5 alpha-series, 3 beta-ethyl, -propyl, -trifluoromethyl and -(benzyloxy)methyl, as well as substituents of the form 3 beta-XCH(2), where X is Cl, Br, or I or contains unsaturation, show limited efficacy in inhibiting [S-35]TBPS binding. In the 5 beta-series, the unsubstituted parent 2 is a two-component inhibitor, whereas all of the 3 beta-substituted derivatives of 2 inhibit TBPS via a single class of binding sites. In addition, all of the 3-substituted 5 beta-sterols tested are full inhibitors of [S-35]TBPS binding. Electrophysiological measurements using alpha 1 beta 2 gamma 2L receptors expressed in oocytes show that 3 beta-methyl- and 3 beta-(azidomethyl)-3 alpha-hydroxy-5 alpha-pregnan-20-one (6 and 22, respectively) are potent full efficacy modulators and that 3 alpha-hydroxy-3 beta-(trifluoromethyl)-5 alpha-pregnan-20-one (24) is a low-efficacy modulator, confirming the results obtained from [S-35]TBPS binding. These results indicate that modification of the 3 beta-position in 1 and 2 maintains activity at the neuroactive steroid site on the GABA(A) receptor. In animal studies, compound 6 (CCD 1042) is an orally active anticonvulsant, while the naturally occurring progesterone metabolites I and 2 are inactive when administered orally, suggesting that 3 beta-substitution slows metabolism of the S-hydroxyl, resulting in orally bioavailable steroid modulators of the GABA(A) receptor.
[EN] ANDROSTANE AND PREGNANE SERIES FOR ALLOSTERIC MODULATION OF GABA RECEPTOR<br/>[FR] SERIES DE L'ANDROSTANE ET DE LA PREGNANE PRODUISANT UNE MODULATION ALLOSTERIQUE DU RECEPTEUR DU GABA
申请人:COCENSYS, INC.
公开号:WO1996016076A1
公开(公告)日:1996-05-30
(EN) Methods, compositions, and compounds for modulating the GABAA receptor-chloride ionophore complex to alleviate stress, anxiety, seizures, mood disorders, PMS and PND and to induce anesthesia.(FR) Procédés, compositions et composés servant à moduler le complexe ionophore de chlorure et récepteur du GABAA, permettant ainsi d'atténuer le stress, l'anxiété, les crise d'épilepsie, les troubles de l'humeur, la dépression post natale et le syndrome prémenstruel, et de provoquer l'anesthésie.