TREMORGENIC MYCO-TOXINS FROM PENICILLIUM-CRUSTOSUM - BIOSYNTHESIS OF PENITREM-A
TREMORGENIC MYCO-TOXINS FROM PENICILLIUM-CRUSTOSUM - BIOSYNTHESIS OF PENITREM-A
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DOI：
10.1039/p19830001863
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发表时间：
1983-01-01
期刊：
影响因子：
--
通讯作者：
HULL, WE
中科院分区：
文献类型：
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作者：
DE JESUS, AE;GORSTALLMAN, CP;HULL, WE
已经用13 C-和2 H-标记的前体，即[1- 13 C]-、[2- 13 C]-、[1，2 - 13 C2]-和[1- 13 C，2- 2 H3]-乙酸盐、[2- 13 C]-、[2，3 - 13 C2]-、[2- 2 H2]-和[5- 2 H2]-甲羟戊酸盐研究了青霉烯A的生物合成。结果表明，penitrem A是来自色氨酸，这有助于吲哚部分的代谢产物，香叶基香叶基焦磷酸，和两个异戊烯焦磷酸单位。在生物合成过程中发生涉及甲羟戊酸单元的2，3-键的1，2-键迁移，并导致观察到两个[1- 13 C]乙酸酯衍生的碳原子之间和两个[2- 13 C]乙酸酯衍生的碳原子之间的单键（C，C）偶联。对[2- 13 C]乙酸酯衍生的青霉烯A中的单键（C，C）偶合常数的分析表明，在发酵过程中形成了[1，2 - 13 C2]乙酸酯。虽然从羟基异丙基损失水以形成存在于青霉烯A中的异丙烯基官能团应继续保持两个甲基的立体化学完整性，但双键的异构化导致13 C标记在C-36和C-38之间均匀分布，并排除任何立体化学扣除。
The biosynthesis of penitrem A has been studied with both 13C- and 2H-labelled precursors, viz. [1-13C]-, [2-13C]-, [1,2-13C2]-, and [1-13C,2-2H3]-acetate, [2-13C]-, [2,3-13C2]-, [2-2H2]- and [5-2H2]-mevalonate. The results show that penitrem A is derived from tryptophan, which contributes the indole moiety of the metabolite, geranylgeranylpyrophosphate, and two isopentenylpyrophosphate units. A 1,2-bond migration, involving the 2,3-bond of a mevalonate unit, occurs in the course of the biosynthesis and results in the observation of a one-bond (C,C) coupling between two [1-13C]acetate-derived carbon atoms and between two [2-13C]acetate-derived carbon atoms. Analysis of the one-bond (C,C)coupling constants in [2-13C]acetate-derived penitrem A showed that [1,2-13C2]acetate was formed during the fermentation. Although loss of water from an hydroxyisopropyl group to form the isopropenyl function present in penitrem A should proceed with retention of the stereochemical integrity of the two methyl groups, isomerization of the double bond causes equal distribution of 13C label between C-36 and C-38 and precludes any stereochemical deductions.