Elucidation of deodrant mechanism of bark pophphanols using molecular orbital calcularion

与城市相比，在森林和草原等植物生长的地方，我们不会感到难闻的气味。植物的吸收和分解能力可能导致这种现象。特别是树皮、树叶等外部组织被认为是固定大气污染物和二氧化碳、保护树体的重要组织。本文研究了几种针叶树树皮及其所含原花青素对氨（NH_3）和甲基硫醇（CH_3SH）的除臭活性。采用气体检测管和气相色谱质谱联用法测定其除臭活性。以一种日本苹果酒和两种日本松为原料制备的树皮粕对NH_3有较强的除臭活性，对CH_3SH有较好的除臭活性。他们的内部树皮和木粉也进行了测试。木粕的活性极低，内皮粕的活性处于两种组织的中间，没有物种关系。另一方面，从树皮粕中提取的原花青素和热带木材、绿茶和乌龙茶中提取的几种多酚对CH_3SH的除臭作用很小或没有。然而，柿子中的多酚具有相当好的活性。根据之前的一篇论文，认为柿子中的原花青素与体内产生的乙醛发生反应，将原花青素转化为聚合多酚。为了模拟聚合反应，在酸性条件下合成了树皮原花青素与乙醛的缩合物，并进行了除臭活性测试。冷凝物对两种气体的活性都有很大的改善，如柿子多酚所示。

We do not feel a disgusting smell in the places growing plants such a forest and a prairie compared to in a city. Absorbing and decomposing abilities of a plant may cause this phenomenon. Especially external tissues such as bark and leaf are considered to be important tissues to fix atmospheric pollutants and carbon dioxide as well as to protect the tree body. In this paper, the deodorant activity of several coniferous barks and proanthocyanidins contained in the bark on ammonia (NH_3) and methyl mercaptan (CH_3SH) were investigated. The deodorant activity was measured with a decicator method using gas detector tube and by GC/MS. Outer bark meals prepared from a Japanese cider and two Japanese pines have strong deodorant activities on NH_3 and reasonably good one on CH_3SH. Their inner bark and wood meals were also tested. The activities of wood meals were extremely lower and that of inner bark meals were the middle of the two tissues without relations of the species. On the other hand proanthocyanidins extracted from bark meal and several polyphenols from tropical wood, green tea and oolong tea showed little or no deodorant activities on CH_3SH. However the polyphenls from persimmon was a reasonably good activity. According to a previous paper, it is considered that the proanthocyanidins in persimmon fruit react with acetaldehyde produced in vivo to convert proanthocyanidins into polymeric polyphenols. In order to mimic the polymerization the condensates of proanthocyanidins from bark with acetaldehyde under acidic condition were synthesized and tested for deodorant activity. The condensates resulted in a large improvement of the activity on both gasses as shown in persimmon polyphenols.