Dueker S R, Lamé M W, Segall H J
Department of Veterinary Molecular Biosciences, University of California, Davis 95616, USA.
Arch Toxicol. 1995;69(10):725-8. doi: 10.1007/s002040050240.
Many of the commonly studied pyrrolizidine alkaloids (PAs) are built upon the subgroup retronecine (RET), which is released from the parent molecule by either base catalyzed or enzymatic hydrolysis of the ester linkages. The rate of appearance of RET in a hydrolytic study would thus reflect the rate of hydrolysis for the PA being tested. We have developed a gas chromatographic (GC) method to measure the release of RET from incubations of PAs with the guinea pig carboxylesterase, GPH1. The PAs tested were the following: jacobine (JAB), jacozine (JAZ), retrorsine (RES), and seneciphylline (SNP). The KmS for SNP and JAZ were determined to be 64.9 and 349.2 microM, respectively. In addition, a qualitative assessment of hydrolytic activity toward a radiolabelled mixture of retrorsine/riddelliine (RES/RIL) was performed with HPLC and radiometric detection.
许多常见的被研究的吡咯里西啶生物碱（PAs）都是基于次级碱饱和氮原子（RET）构建的，RET是通过酯键的碱催化或酶促水解从母体分子中释放出来的。因此，在水解研究中RET出现的速率将反映所测试PA的水解速率。我们开发了一种气相色谱（GC）方法来测量PA与豚鼠羧酸酯酶GPH1孵育时RET的释放量。所测试的PA如下：雅各宾碱（JAB）、雅各嗪（JAZ）、倒千里光碱（RES）和苦叶碱（SNP）。SNP和JAZ的米氏常数分别测定为64.9和349.2微摩尔。此外，还采用高效液相色谱和放射性检测对倒千里光碱/里德利碱（RES/RIL）的放射性标记混合物进行了水解活性的定性评估。
