Enzymes Catalyzing the Biosynthesis of Alkaloids (Chemistry)

有机与高分子化学计划中的这一研究项目旨在更深入地了解某些关键有机化合物是如何在植物中合成的。含有特定酶的无细胞系统将从生物碱生产植物的不同部分获得。将考察这些无细胞提取物在生物合成最终生物碱过程中催化已知或可疑中间体转化的能力。一般来说，这些酶将通过使用专门标记的(碳、氚和氢)底物进行检测，使用这些底物将有助于产品和瞬时中间体的鉴定。将被研究的一些转化是：(1)尼古丁的去甲基化(烟叶)；(2)可卡因的生物合成(红花古柯叶)；(3)苯丙氨酸转化为(S)-托洛酸(多瑙根)；(4)托皮酮转化为托品(曼陀罗根)；(5)辛酸转化为5-氧代辛酸(斑叶)；和(6)邻琥珀基苯甲酸转化为紫草宁(石斛茎叶)。

This research project in the Organic and Macromolecular Chemistry Program is designed to provide deeper understanding of how certain key organic compounds are synthesized in plants. Cell-free systems containing specific enzymes will be obtained from various parts of alkaloid-producing plants. The ability of these cell-free extracts to catalyze the transformation of known or suspected intermediates in the biosynthesis of the ultimate alkaloids will be examined. In general, the enzymes will be assayed by the use of specifically labeled (carbon, tritium, and deuterium) substrates, the use of which will facilitate identification of products and transient intermediates. Some transformations which will be studied (with the potential source of the enzymes indicated in parenthesis) are the following: (1) the demethylation of nicotine (Nicotinia glutinosa leaves); (2) cocaine biosynthesis (Erythroxylon coca leaves); (3) phenylalanine conversion to (s)-tropic acid (Danutura innoxia roots); (4) tropinone conversion to tropine (Datura innoxia roots); (5) octanoic acid conversion to 5-oxo-octanoic acid (Conium maculatum leaves); and (6) o-succinyl benzoic acid conversion to shihunine (Dendrobium pierardii stems and leaves).