THE MIGRATION AND ELIMINATION OF HYDROGEN DURING BIOSYNTHESIS OF CHOLESTEROL FROM SQUALENE.
THE MIGRATION AND ELIMINATION OF HYDROGEN DURING BIOSYNTHESIS OF CHOLESTEROL FROM SQUALENE.
复制标题
角鲨烯生物合成胆固醇过程中氢的迁移和消除。
DOI：
10.1021/ja01092a038
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发表时间：
1965
影响因子：
15
通讯作者：
E. Caspi
中科院分区：
文献类型：
--
作者：
J. Cornforth;R. H. Cornforth;C. Donninger;G. Popják;Y. Shimizu;S. Ichii;E. Forchielli;E. Caspi
由4R-4-H3-甲戊酸生物合成的羊毛甾醇和胆固醇分别保留了中间体角鲨烯中存在的六个标记原子中的五个和三个。胆固醇被降解，在保留的三个H‘，J原子中，有一个在17a-位。剩下的两个氚原子很可能位于C-20和C-24。这种H3的损失、保留和分布模式与角鲨烯环化的理论机理完全一致。类固醇核中没有氚证实了生物合成过程中C-3羟基的中间氧化，并表明当形成胆固醇的双键时，5a氢原子被消除，而不是重排。
Lanosterol and cholesterol biosynthesized from 4R-4-H3-mevalonic acid retain, respectively, five and three of the six labeled atoms present in the intermediate squalene. The cholesterol was degraded and, of the three H', J atoms retained, one is at the 17a-position. The remaining two tritium atoms are most probably located at C-20 and C-24. This pattern of loss, retention, and distribution of H3 is in complete harmony with the theoretical mechanism of squalene cyclization. The absence of tritium in the steroidal nucleus confirms the intermediateoxidation of the C-3 hydroxyl during biosynthesis and shows that when the doublebond of cholesterol is formed the 5a-hy-drogen atom is eliminated, not rearranged.