Five acidic 3', 5'-diesters of 5-fluoro-2'-deoxyuridine (FUdR) including 3-carboxypropionate, 4-carboxybutyrate, 5-carboxypentanoate, 6-carboxyhexanoate and 7-carboxyheptanoate were synthesized, and their susceptibility to porcine liver, rat liver homogenate, rat intestinal homogenate and rat plasma esterase preparations was studied. The susceptibility of the derivatives to porcine liver esterase preparation increased as the number of methylene groups in the ester promoiety increased in both acidic (pH 5.0) and neutral (pH 7.0) solutions. The derivatives showed about 100 times higher reactivity to the esterase at pH 5.0 than at pH 7.0. With the rat tissue homogenates and plasma preparations, the longer the ester chain the higher the susceptibility, except for 3', 5'-bis (3-carboxypropionyl) FUdR (I) with rat liver homogenate. Though the reactivity of I was the lowest with porcine liver esterase preparation and not measurable with rat intestinal homogenate and plasma, I showed the highest reactivity with the rat liver homogenate.
合成了 5-
氟-
2'-脱氧尿苷(FUdR)的五种酸性 3',5'-二酯,包括 3-羧基
丙酸酯、4-羧基
丁酸酯、5-羧基
戊酸酯、6-羧基
己酸酯和 7-羧基
庚酸酯,并研究了它们对猪肝、大鼠肝匀浆、大鼠肠匀浆和大鼠血浆酯
酶制剂的敏感性。在酸性(pH 值 5.0)和中性(pH 值 7.0)溶液中,随着酯原基中亚甲基数目的增加,衍
生物对猪肝酯
酶制剂的敏感性也随之增加。在 pH 值为 5.0 时,衍
生物与
酯酶的反应性比 pH 值为 7.0 时高约 100 倍。在大鼠组织匀浆和血浆制剂中,酯链越长,敏感性越高,但 3',5'-双(3-羧基丙酰基)FUdR(I)在大鼠肝脏匀浆中除外。虽然 I 在猪肝酯
酶制剂中的反应性最低,在大鼠肠匀浆和血浆中也无法测量,但 I 在大鼠肝匀浆中的反应性最高。