Development of a novel enzymatic synthesis method for trehalose derivatives and its application

研究海藻糖衍生物的酶法合成方法及其在杀虫剂和抗真菌化学品中的应用。海藻糖是一种双糖，通常存在于真菌、藻类和一些无脊椎动物中，但不存在于开花植物和脊椎动物中。它存在于所有昆虫中，在许多昆虫中浓度很高，是主要的血淋巴糖。海藻糖对海藻糖具有特异性水解作用，是蚕卵巢发育过程中血淋巴海藻糖合成糖原过程中的限速酶。因此，海藻酶特异性抑制剂是新型杀虫剂的候选物。我们从Halomonas sp. A -15中纯化了葡萄糖-3-脱氢酶，发现其具有生产海藻糖衍生物的活性。其中的衍生物3,3′-二酮海藻糖对海藻糖具有抑制活性，因此我们研究了其作为杀虫剂或抗真菌化学品的活性。虽然没有抗真菌活性，但可以作为杀虫剂。我们还研究了其高效的生产过程，发现酶生产比微生物生产更有效。以铁氰化钾为电子受体，采用高纯度的葡萄糖-3-脱氢酶，产率可达80%。由此建立了一种高效的生产3,3′-二酮海藻糖的方法，有望成为一种对动物无害的新型有效杀虫剂。

We aimed at the development of novel enzymatic synthesis method of the trehalose derivatives and those applications to insecticides or anti-fungal chemicals. Trehalose is a disaccharide and commonly found in fungi, algae and in several invertebrate phyla but not in flowering plants and vertebrates. It presents in all insects and in many insects it is present in high concetration s and constitutes the major hemolymph sugar. Trehalose secifically hydrolyzed trehalose and is the rate-limiting enzyme in the process of glycogen synthesis from hemolymph trehalose in developing ovaries of the silkworm. Therefore the specific inhibitor for trehalases is a candidate of novel insecticides.We purified glucose-3-dehydrogenase from Halomonas sp. A -15 and found its activity to produce trehalose derivatives. One of those derivatives, 3,3'-diketotrehalose showed an inhibitory activity to trehalose, and therefore we investigated its activity as insecticide or anti-fungal chemicals. It did not show anti-fungal activity but it can be an insecticide. We also investigated its efficient production process, and found the enzymatic production is more efficient than microbial production. By using potassium ferricyanide as electron acceptor and the highly purified glucose-3-dehydrogenase, 80% productivity was attained. Hence we established efficient method to produce 3,3'-diketotrehalose, it can contribute as a novel effective insecticide which is not harmful to animals.