The naturally occurring bitter principle quassin (1) was converted chemically into the gamma-lactone quassilactone (13) in an attempt to enhance its antiplasmodial activity. The in vitro antiplasmodial activity of 13 against Plasmodium falciparum (K1) (IC(50) = 23 microM) was 40-fold greater than that of 1. However, one of the intermediates, compound 8, the 15beta-hydroxy,16-O-m-chlorobenzoyl analogue
为了增强其抗血浆活性,将天然存在的
苦味素quassin(1)
化学转化为γ-内酯,quassilactone(13)。13对恶性疟原虫(K1)(IC(50)= 23 microM)的体外抗血浆活性比1高40倍。但是,其中一种中间体化合物8、15beta-hydroxy,16-Om 1的-
氯苯甲酰基类似物对恶性疟原虫的活性比1高506倍(IC(50)= 1.8 microM),效力仅比
氯喹低3倍。此外,在所有测试的化合物中,有8个显示出最佳的细胞毒性/抗血浆比率(112)。在这项工作过程中,还制备了在C-16处连接的二聚体新quassin醚(6)。6个被发现具有较弱的抗疟原虫活性(IC(50)= 9.7 microM)。