Many kinds of 3, 3-disubstituted-1-(2-chloroethyl)-1-nitrosourea derivatives (V) of aldopentoses were synthesized and tested for antitumor activities against leukemia L1210 and Ehrlich ascites carcinoma. The reaction of aldopentoses with primary amines followed by treatment with 2-chloroethyl isocyanate usually gave a mixture of two or three structural isomers of glycosylureas (III'). Complete isomerization into thermodynamically stable glycopyranosylureas (III) was observed when the mixture of the isomers was dissolved in formic acid. Glycopyranosylureas (III) were nitrosated with 4 equivalents of dinitrogen tetroxide followed by treatment with methanol to give the corresponding nitrosoureas (V) in good yields. A large number of nitrosoureas (V) were remarkably active against leukemia L1210 and Ehrlich ascites carcinoma and showed greater therapeutic ratios than the positive controls, 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea, 3-[(4-amino-2-methyl-5-pyrimidinyl) methyl]-1-(2-chloroethyl)-1-nitrosourea, and 1-(2-chloroethyl)-3-(β-D-glucopyranosyl)-1-nitrosourea. In particular, many of the arabinopyranosyl-nitrosoureas had large therapeutic ratios (more than fifty) against leukemia L1210 and even larger ones (more than a hundred) against Ehrlich ascites carcinoma. These nitrosoureas (V) appear to be activated nonenzymatically by attack of the hydroxyl group of the sugar moiety on the carbonyl group to give the cyclic carbamate (VII) without generation of the isocyanate.
合成了多种3, 3-二取代-1-(2-
氯乙基)-1-亚硝基
脲衍
生物(V),并测试其对白血病L1210和厄赫里希腹
水癌的抗肿瘤活性。醛戊糖与初级胺反应后,再用2-
氯乙基异氰酸酯处理,通常会得到两种或三种结构异构体的糖基
脲(III')的混合物。当将异构体混合物溶解在
甲酸中时,观察到完全异构化为热力学稳定的糖
吡喃糖基
脲(III)。糖
吡喃糖基
脲(III)与4份四氮四氧反应进行亚硝化,然后用
甲醇处理,得到相应的亚硝基
脲(V),产率良好。大量亚硝基
脲(V)对白血病L1210和厄赫里希腹
水癌表现出显著的活性,其治疗比率高于阳性对照药物,1-(2-
氯乙基)-3-环己基-1-亚硝基
脲、3-[(4-
氨基-2-甲基-5-
嘧啶基)甲基]-1-(2-
氯乙基)-1-亚硝基
脲和1-(2-
氯乙基)-3-(β-
D-葡萄糖吡喃糖基)-1-亚硝基
脲。特别是,许多阿拉伯
吡喃糖基亚硝基
脲对白血病L1210的治疗比率超过五十,对厄赫里希腹
水癌的比率更是超过一百。这些亚硝基
脲(V)似乎通过糖分子羟基对羰基的非酶促攻击而被激活,生成环状
氨基酸酯(VII),而不形成
异氰酸酯。