Yuki Gosei Kogyo Co., Ltd.

Japan Tobacco Inc.

Yoichi Mikami

Seiichiro Matsumoto

Yoshinori Hayashi

Toyoki Sato

Ayumi Hasegawa

Atsushi Fukushima

Tadaharu Hieda

Shinjhi Yoshinaka

Yonosuke Sunaga

Kuniaki Ono

Motomu Tan

Michiko Aoki

A glyoxal-guanosine-group compound is prepared either by reacting glyoxal-guanine with any one of ribose-1-phosphate and 2-deoxyribose-1-phosphate in the presence of purine nucleoside phosphorylase, or by reacting glyoxal-guanine with any one selected from the group consisting of uridine, 2'-deoxyuridine and thymidine, together with phosphate ion, in the presence of purine nucleoside phosphorylase and pyrimidine nucleoside phosphorylase. The glyoxal-guanosine-group compound is then decomposed by alkali, whereby a guanosine-group compound consisting of guanosine and 2&#x2032;-deoxyguanosine is prepared.

Method of preparing a guanosine-group compound and an intermediate thereof

A glyoxal-guanosine-group compound is prepared either by reacting glyoxal-guanine with any one of ribose-1-phosphate and 2-deoxyribose-1-phosphate in the presence of purine nucleoside phosphorylase, or by reacting glyoxal-guanine with any one selected from the group consisting of uridine, 2&prime;-deoxyuridine and thymidine, together with phosphate ion, in the presence of purine nucleoside phosphorylase and pyrimidine nucleoside phosphorylase. The glyoxal-guanosine-group compound is then decomposed by alkali, whereby a guanosine-group compound consisting of guanosine and 2&prime;-deoxyguanosine is prepared.

Method of preparing a guanosine-group compound

The present invention provides a method of preparing stably and at a high yield a purine nucleoside compound by utilizing an exchange reaction of a nucleic acid base which is carried out in the presence of an enzyme, and also provides a microorganism capable of producing uracil thymine dehydrogenase or dihydrouracil dehydrogenase. In preparing the purine nucleoside compound, a pyrimidine nucleoside compound and a purine base are subjected to a base exchange reaction in an aqueous solution containing phosphate ions in the presence of pyrimidine nucleoside phosphorylase and purine nucleoside phosphorylase. The pyrimidine base formed by the base exchange reaction is converted by a microorganism or an enzyme derived from the microorganism into a compound incapable of acting as substrates of pyrimidine nucleoside phosphorylase and purine nucleoside phosphorylase so as to obtain a desired product of purine nucleoside compound.

Method of preparing purine nucleoside compound

This invention relates to a chemical for protection of plants and removal of plant viruses and its producing method, which is applicable to the prevention of viral disease in the fields of agriculture and horticulture. That is, this invention relates to a chemical for protection of plants and removal of plant viruses which contains a plant virus prevention active substance as its effective ingredient and which was cultivated using a fungus selected from the genus Fomes and was produced in fungi or medium.

Chemicals for protection of plant and removal of plant virus, and

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Tokyo, Japan

Yoichi Mikami