Chemical Transformation of Terpenoids. X. Ionophoretic Activities of Macrocyclic Lactone Epoxides Synthesized from Geraniol.
作者:Hirotaka SHIBUYA、Kazuyoshi OHASHI、Norihiko NARITA、Toshimasa ISHIDA、Isao KITAGAWA
DOI:10.1248/cpb.42.293
日期:——
Two coronand-type 18-membered lactone epoxides, i.e., geranyl dimeric lactone diepoxide (GL2E2, 10) and tetraepoxide (GL2E4, 11), were synthesized from geraniol as diastereomeric mixtures. Among them, GL2E4 (11) was shown to exhibit ion-transport activity for Ca2+ ion in the test using a W-07 (liquid-membrane type) apparatus and ion-permeation activities for Ca2+ and K+ ions across the human erythrocyte membrane. Isolation of six component diastereomers of GL2E4 (11) [GL2E4-1 (11c), -2 (11d), -3 (11e), -4 (11f), -5 (11g), -6 (11h)], was effected by HPLC separation of two diastereomeric tetraepoxides (11a, 11b) which were prepared from two diepoxides (GL2E2-1, 10a and GL2E2-2, 10b). The relative stereostructures of these diastereomers were determined by a combination of X-ray diffraction and 1H-NMR analyses. Among the six diastereomers, S2-symmetrical GL2E4-4 (11f) exhibited the strongest ion-transport activity for Ca2+ ion while C2-symmetrical GL2E4-6 (11h) exhibited the strongest ion-permeation activity for Ca2+ ion across the human erythrocyte membrane.
合成了两种冠烷型18元内酯环氧化物,即香叶醇二聚体内酯二环氧化物(GL2E2,10)和四环氧化物(GL2E4,11),它们以二烯异构体混合物的形式存在。测试结果显示,GL2E4(11)在使用W-07(液膜类型)设备的实验中对Ca2+离子表现出离子运输活性,并且在通过人红细胞膜对Ca2+和K+离子表现出离子渗透活性。从两种二环氧化物(GL2E2-1,10a和GL2E2-2,10b)分离出六种组分的二烯异构体GL2E4(11)[GL2E4-1(11c),-2(11d),-3(11e),-4(11f),-5(11g),-6(11h)],这是通过HPLC分离两种二烯异构体四环氧化物(11a,11b)实现的。这些二烯异构体的相对立体结构通过X射线衍射和1H-NMR分析相结合的方法来确定。在这六种二烯异构体中,S2对称的GL2E4-4(11f)对Ca2+离子展现出最强的离子运输活性,而C2对称的GL2E4-6(11h)则在通过人红细胞膜对Ca2+离子的离子渗透活性中表现最强。