Block of human NaV1.5 sodium channels by novel α-hydroxyphenylamide analogues of phenytoin
摘要:
Voltage-gated sodium (Na) channels are a critical component of electrically excitable cells. Phenytoin (diphenylhydantoin, DPH) is an established sodium channel blocker and is a useful anticonvulsant and class 1b antiarrhythmic, and has been effectively used in the treatment of neuropathic pain. In this study, we have synthesized novel alpha-hydroxyphenylamide analogues of diphenylhydantoin and examined their ability to inhibit human Na(v)1.5 sodium channels expressed in Chinese Hamster Ovary (CHO-K1) cells. Phenyl ring substitutions were examined including para-methyl, para-fluoro, para-chloro, ortho-chloro and meta-chloro. We have found that phenyl ring substitutions with electron withdrawing properties resulted in compounds with greater activity. In comparison to diphenylhydantoin, the novel chloro-substituted (alpha-hydroxyphenylamide compounds produced as much as a 20-fold greater tonic and frequency-dependent blockade of Na(v)1.5 channels with an IC50 value of 14.5 muM. In addition, the chloro-substitutions have position specific state dependent blocking properties. The ortho-, ineta- and para-chloro substitutions have an 8-, 13- and 3-fold increased affinity for the inactivated state, respectively. Molecular modeling suggests that these differences in affinity are due to a direct interaction with the receptor. Comparing models of diphenylhydantoin to the novel alpha-hydroxyphenlyamide compound suggests that the increased activity may be due to an optimized phenyl ring position and increased molecular volume. This information may be useful in the development of more potent sodium channel blockers. (C) 2004 Elsevier B.V. All rights reserved.
Block of human NaV1.5 sodium channels by novel α-hydroxyphenylamide analogues of phenytoin
摘要:
Voltage-gated sodium (Na) channels are a critical component of electrically excitable cells. Phenytoin (diphenylhydantoin, DPH) is an established sodium channel blocker and is a useful anticonvulsant and class 1b antiarrhythmic, and has been effectively used in the treatment of neuropathic pain. In this study, we have synthesized novel alpha-hydroxyphenylamide analogues of diphenylhydantoin and examined their ability to inhibit human Na(v)1.5 sodium channels expressed in Chinese Hamster Ovary (CHO-K1) cells. Phenyl ring substitutions were examined including para-methyl, para-fluoro, para-chloro, ortho-chloro and meta-chloro. We have found that phenyl ring substitutions with electron withdrawing properties resulted in compounds with greater activity. In comparison to diphenylhydantoin, the novel chloro-substituted (alpha-hydroxyphenylamide compounds produced as much as a 20-fold greater tonic and frequency-dependent blockade of Na(v)1.5 channels with an IC50 value of 14.5 muM. In addition, the chloro-substitutions have position specific state dependent blocking properties. The ortho-, ineta- and para-chloro substitutions have an 8-, 13- and 3-fold increased affinity for the inactivated state, respectively. Molecular modeling suggests that these differences in affinity are due to a direct interaction with the receptor. Comparing models of diphenylhydantoin to the novel alpha-hydroxyphenlyamide compound suggests that the increased activity may be due to an optimized phenyl ring position and increased molecular volume. This information may be useful in the development of more potent sodium channel blockers. (C) 2004 Elsevier B.V. All rights reserved.
TiCl<sub>4</sub>-Catalyzed Indirect Anti-Markovnikov Hydration of Alkynes: Application to the Synthesis of Benzo[<i>b</i>]furans
作者:Lutz Ackermann、Ludwig T. Kaspar
DOI:10.1021/jo070887i
日期:2007.8.1
An efficient methodology for the indirect anti-Markovnikov hydration of unsymmetrically substituted terminal and internal alkynes is based on TiCl4-catalyzed hydroamination reactions. Its application to ortho-alkynylhaloarenes, followed by a copper-catalyzed O-arylation, provides flexible access to substituted benzo[b]furans.
一种不对称取代的末端和内部炔烃的间接反马氏水合的有效方法是基于TiCl 4催化的加氢胺化反应。其在邻炔基卤代芳烃上的应用,然后在铜催化的O-芳基化反应中,可以灵活地获得取代的苯并[ b ]呋喃。