A (IAS-A) isolated from Thermomonospora alba showed weak inhibition against topoisomerase (topo) I (IC(50)=307microM). To get more strong inhibition, derivatives of IAS-A were prepared and their structure-activity relationships against topo I and II were investigated. The addition of hydroxyl group on aromatic rings increased the activities, 3-(3,4,5-trihydroxybenzylidene)-5-hydroxy-3H-benzofuran-2-one
从白热单孢菌中分离得到的异潮红素A(IAS-A)对拓扑异构酶(topo)I的抑制作用较弱(IC(50)= 307microM)。为了获得更强的抑制作用,制备了IAS-A衍
生物,并研究了它们对topo I和II的构效关系。芳香环上羟基的添加增加了活性,3-(3,4,5-三羟基亚苄基)-5-羟基-3H-
苯并呋喃-2-酮(IAS-9)表现出较强的抑制作用(IC(50)= 3microM ),同时增加羟基对多种癌细胞的生长抑制作用,而IAS-9表现出最强的抑制作用。与
喜树碱和
依托泊苷不同,IAS-9既不能稳定DNA-拓扑可裂解的复合物,也不能插入DNA中,并且非竞争性地抑制了topo I和II。