microM; IC(50) human: 0.74 microM). The inhibitory potency depends markedly on the stereochemistry at C20 of the inhibitors. This effect is more pronounced for the rat enzyme. Tested for selectivity, the highly potent inhibitors show poor inhibitory activity toward P450 arom, P450 scc, P450 TxA(2), and 5alpha-reductase. Tested for in vivo activity, 3 and 8 (0.019 mmol/kg) decreased the plasma testosterone
在寻找有效的P450 17
抑制剂中,合成了雄激素
生物合成中的关键酶,合成了一系列甾体
抑制剂并针对大鼠和人P450 17进行了测试。小的脂肪族杂环(
氮丙啶,
环氧乙烷,
噻吩烷,重
氮丙啶,重氮基,氮杂
环丁烷)是引入到anstrost-5-en-3beta-ol的17beta位置。在确定
氮丙啶是最适合与血红素
铁配合的官能团后,对甾体骨架进行修饰以进一步优化。对于21种测试化合物,发现了对P450 17的广泛抑制效力。对人和大鼠酶最有效的
抑制剂是
氮丙啶化合物3(IC(50)大鼠:0.21 microM,K(i)= 3 nM; IC(50)人类:0.54 microM,K(i)= 8 nM), 5(IC(50)大鼠:0.43 microM,K(i)= 7 nM; IC(50)人类:0.29 microM,K(i)= 4 nM)和8(21R:21S = 1:1; IC(50)大鼠:0.53 microM,K(i)=