Mitsui Chemicals, Inc.

Yasushi Fukuiri

Hiroki Ishibashi

Toshihiro Oikawa

Kiyoteru Nagahara

Yasuko Matsuba

Tomoyuki Ando

Tadashi Araki

Hironori Komatsu

Atsushi Sakuma

Kaori Matoishi

Toshifumi Yamaki

Hitoki Miyake

Hideki Umetani

Kazuhiko Togashi

Reiko Abe

Ichirou Ikeda

Tsuyoshi Inoue

Takeshi Nakamura

Tomoyuki Kawabata

Katsuyuki Takahashi

Provided is a purified lactic acid-glycolic acid copolymer, preferably in the form of powder, having a reduced content of dimers such as residual lactide and glycolide that can be produced by a simple industrial process without the use of any high-shear special device. Further provided is a high-purity lactic acid-glycolic acid copolymer which has small amounts of dimers such as residual lactide and glycolide and small amounts of a low-molecular weight lactic acid-glycolic acid copolymer or a salt thereof and which has a small ratio of weight average molecular weight to number average molecular weight (Mw/Mn). The copolymer can be produced in accordance with a defined process.

Process for producing a lactic acid-glycolic acid copolymer or a salt thereof

The invention provides a method for producing a cytosine nucleoside compound from pentose-1-phosphate and cytosine or a derivative thereof using a nucleoside phosphorylase reactive to cytosine or a bacterium having the enzyme activity. The invention also provides a method for specifically reducing an activity to degrade the substrates or the product, resulting in efficient production of the cytosine nucleoside compound. According to the invention, little by-product is produced in producing cytonucleocide compounds.

Method for producing cytosine nucleoside compounds

A novel gluconate dehydratase derived fromand a gene encoding the gluconate dehydratase are provided. By reacting the gluconate dehydratase or a transformed cell containing the gene with an aldonic acid, the corresponding 2-keto-3-deoxyaldonic acid can be efficiently produced.

Gluconate dehydratase

A protected 2'-deoxycytidine is purified by precipitating the protected 2&#x2032;-deoxycytidine represented by general formula (3) in the form of a hydrated crystal from a solution containing the protected 2&#x2032;-deoxycytidine and water, and by recovering the protected 2&#x2032;-deoxycytidine:wherein R1 represents a 4-methoxytrityl, 4, 4&#x2032;-dimethoxytrityl, or triphenylmethyl group; and B1 represents a cytosine group having a protected amino group. The compound represented by general formula (3) is, in particular, a protected 2&#x2032;-deoxycytidine represented by formula (4):The 2&#x2032;-deoxycytidine is used as a raw material for antisense DNA.

Method for purifying protected 2'-deoxycytidines and hydrated crystals thereof

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Fukuoka, Japan

Yasushi Fukuiri