METABOLISM OF AROMATIC COMPOUNDS

我们建议继续我们的生物化学研究，对几种 芳香族生氰苷，天然产物，存在于生氰中 植物。这些研究是为了获得基本的生化指标。 关于天然产物新陈代谢的信息 任何确立的原则都将适用于其他类似的 化合物。植物天然产物包括许多物质(生物碱、 香豆素、黄酮类、硫代葡萄糖苷)，具有药用和 毒物学兴趣。芳香生氰苷的来源是 L-酪氨酸和L-苯丙氨酸的生物合成序列 相应的N-羟基氨基酸、缩醛、腈和氰基。二 四个步骤中的一个是由混合功能的加氧酶催化的。这个 高粱微生物体催化的生物合成序列是代谢的 导流，以便更有效地利用现场生产的中间体 而不是从外部添加到微粒体内的相同中间体。我们建议 看看其他生氰苗(野豌豆和亚麻)的颗粒是否 也同样被通灵。因为溶解几种酶的努力 没有产生一种可溶的、纯化的蛋白质，其分子 重量(大小)可以确定，我们将使用辐射技术 测定失活所涉及的酶(S)的相对分子质量。 这样的信息应该表明这几种酶是否是分开的 催化授权或它们是否以多酶复合体的形式发挥作用。 生氰高粱幼苗具有有效的生物合成系统 从淀粉中生产酪氨酸。因为人们对这种酶知之甚少 或它们的调控，我们建议研究莽草酸途径。 这样的苗木。特别是，我们将研究叶绿体的作用。 在这个过程中，由于这个细胞器现在被认为是 植物中氨基酸的合成。最后，推定的机制。 脱水反应(乙醛肟大于丁腈水)，它似乎 需要对NADPH进行研究。

We propose to continue our biochemical studies of the metabolism of several aromatic cyanogenic glycosides, natural products, which occur in cyanogenic plants. The studies are desgined to obtain fundamental biochemical information concerning the metabolism of natural products on the assumption that any principles established will be applicable to other such compounds. Plant natural products include many substances (alkaloids, coumarins, flavonoids, glucosinolates) which are of medicinal and toxicological interest. Aromatic cyanogenic glycosides are derived from L-tyrosine and L-phenylalanine by a biosynthetic sequence involving the corresponding N-hydroxyamino acid, aldoxime, nitrile and cyanoydrin. Two of the four steps are catalyzed by mixed-function oxygenases. The biosynthetic sequence catalyzed by sorghum microsomes is metabolically channeled so that intermediates produced in situ are used more effectively than the same intermediates added externally to the microsomes. We propose to see whether particules from other cyanogenic seedlings (vetch and flax) are similarly channeled. Because efforts to solubilize the several enzymes involved have not yielded a soluble, purified protein whose molecular weight (size) could be determined, we shall used the technique of radiation inactivation to measure the molecular weight of the enzyme(s) involved. Such information should indicate whether the several enzymes are separate catalytic entitles or whether they function as a multi-enzyme complex. Cyanogenic sorghum seedlings possess an effective biosynthetic system for producing tyrosine from starch. Since little is known about the enzymes involved or their regulation, we propose to study the shikimate pathway in such seedlings. In particular, we will examine the role of the chloroplast in this process, since this organelle is now recognized as a site of synthesis of amino acids in plants. Finally, the mechanism of putative dehydration reaction (aldoxime greater than nitrile + H2O) which appears to require NADPH will be studied.