Modulation of GABA<sub>A</sub>-Receptors by Honokiol and Derivatives: Subtype Selectivity and Structure–Activity Relationship
作者:Barbara Taferner、Wolfgang Schuehly、Antje Huefner、Igor Baburin、Katharina Wiesner、Gerhard F. Ecker、Steffen Hering
DOI:10.1021/jm200186n
日期:2011.8.11
A series of 31 analogues of the neolignan honokiol (a major constituent of Magnolia officinalis) was synthesized, and their effects on GABA(A) receptors expressed in Xenopus oocytes were investigated. Honokiol enhanced chloride currents (I-GABA) through GABA(A) receptors of seven different subunit compositions with EC50 values ranging from 23.4 mu M (alpha(5)beta(2)) to 59.6 mu M (alpha(1)beta(3)). Honolciol was most efficient on alpha(3)beta(2) (maximal IGABA enhancement 2386%) > alpha(2)beta(2) (1130%) > alpha(1)beta(2) (1034%) > alpha(1)beta(1) (260%)). On alpha(1)beta(2)-receptors, N-substituted compounds were most active with 3-acetylamino-4'-O-methylhonolciol (31), enhancing I-GABA by 2601% (EC50 (alpha(1)beta(2)) = 3.8 mu M). Pharmacophore modeling gave a model with an overall classification accuracy of 91% showing three hydrophobic regions, one acceptor and one donor region. Unlike honokiol, 31 was most efficient on alpha(2)beta(2)- (5204%) > alpha(3)beta(2)- (3671%) > alpha(1)beta(2)-receptors (2601%), suggesting a role of the acetamido group in subunit-dependent receptor modulation.