Studies on Biogeneration of Plant Flavor and Its Physiological Function

Ⅰ）通过研究脂肪氧合酶和脂肪酸氢过氧化物裂解酶的底物特异性，阐明了这两种酶的反应机理。通过分析，可以详细地分析控制“绿色气味“排放的因素。这些研究使我们认识到“绿色气味”的生理作用。2.植物如何应对压力？使用在生长室中生长的豌豆幼苗。当幼苗的下部叶片受到伤害胁迫时，上部叶片产生反应并形成C6-醛。通过这些调查，我们获得了一些新的发现和有趣的事实，这是非常重要的植物生理学的科学领域。iii）作为“绿色气味”的主要成分的C6-醛的量在完整的植物组织中非常低，而在对组织进行染色时，这些醛迅速形成。由于在体外可以检测到参与C6-醛形成的酶系统的高活性，因此这些酶系统可以被认为是C6-醛形成的主要途径。 ...更多信息 酶系统被认为以潜伏形式存在于完整的植物组织中。潜在形式的酶系统的活化应在均质化后迅速发生。对这一现象的深入分析揭示了控制该酶系统活性状态的机理。iv）分析了从茶叶释放和在茶叶中形成的C6-醛的量。醛类的排放速率在5月份有所增加。有趣的是，从茶叶中释放的醛的组成不同于存储在leafe.A-II组酶活性分布形成海藻风味：脂肪酸转化为长链醛在海藻中已被广泛研究。已揭示长链醛从组织释放到海水中。这一事实表明，这些醛类化合物在海洋生态学中具有重要的作用。A-I，C合作组大多数植物来源的风味化合物被认为是由类胡萝卜素形成的。以大豆脂肪氧合酶为模型实验体系，研究了其与多烯化合物视黄酸的共氧化活性。通过这些研究，阐明了共氧化反应的机理。B、C协同组风味化合物的含量一般很低。因此，很难确定这些风味化合物的立体化学。施赖尔和他在维尔茨堡大学的同事试图确定葡萄中作为糖苷配基的挥发性化合物的立体化学。我们通过合作，讨论了一种测定少量化合物立体化学的方法，并决定采用手性气相色谱分析和二维气相色谱分析。用这种方法，确定了一组芳樟醇类化合物的绝对构型。少

A-I Group i)With investigating substrate specificities of lipoxygenase and fatty acid hydroperoxide lyase, reaction mechanism of these two enzymes were elucidated. From the results, factors who control the emission of "Green odor"could be analyzed in detail. These investigation led us to know the physiological roles of "Green odor". ii) How plants respond to stresses? Pea seedlings which were grown in a growth chamber were used. When lowest leaves of the seedlings were stressed with wounding, the upper leaves responded and formed C6-aldehydes. With these investigations, we obtained several novel findings and interesting facts which are very important to a scientific field of plant physiology. iii)Th amounts of C6-aldehydes which are major constituents of "Green odor" are very low in intact plant tissue, while, upon homogenizing the tissue, these aldehydes are rapidly formed. Because high activities of enzyme systems involved in C6-aldehyde formation could be detected in vitro, these en … More zyme systems are thought to present in intact plant tissue as latent forms. Activation of the latent-form enzyme systems should be occurred rapidly after homogenization. Precise analyses on this phenomenon revealed the mechanism controlling the activity state of this enzyme system. iv)Amounts of C6-aldehydes emitted from and formed in tea leaves have analyzed. The rate of emission of aldehydes increased temporally during May. Interestingly, the composition of aldehydes emitted from tea leaves differed from that of stored in the leaves.A-II Group Distribution of enzyme activity forming seaweeds flavor : Conversion of fatty acid to long chain aldehyde in sea algae has been extensively investigated. It has been revealed that the long chain aldehydes are emitted from tissues to sea-water. This fact indicates that these aldehydes have significant roles in sea-ecology.A-I, C Co-operative group Most of flavor compounds of plant origins are thought to be formed from carotenoids. As a model experimental system, cooxidation activity of soybean lipoxygenase has been studied with a polyene compound, retinoic acid. With these studies, reaction mechanism of cooxidation has been clarified.B, C Co-operative group The amounts of flavor compounds are generally very low. Thus, it is very difficult to determine stereo chemistry of these flavor compounds. P.Schreier and his co-workers in Wurzburg University have been tried to determine stereo chemistry of volatile compounds found in grapes as aglycons. We, with co-operating, discussed about a methodology to determine stereo chemistry of a compound of small amount, and decided to used chiral GC analyses and two-dimensional GC analyses. With this strategy, absolute configurations of a group of linalool-like compounds have been determined. Less