Ajinomoto Co., Ltd.

Asahi Glass Company, Limited

Hirokazu Morisawa

Akihiro Yamazaki

Yoshio Oda

Susumu Shibahara

Fumihiro Yoshinaga

Koji Mitsugi

Keiichi Uchida

Takeshi Miyoshi

Takashi Utagawa

Sachiko Mukai

Tohru Nishihara

Eiko Ohtsuka

Hideo Inoue

There is disclosed a compound having a double chain which is composed of an RNA (+chain) and a complementary DNA (-chain), wherein a portion of the DNA (-chain) has been replaced by an RNA or a derivative thereof, and wherein, when the compound is subjected to the action of an enzyme having a ribonuclease H activity, it is possible to preferentially cleave the RNA (+chain) in a position corresponding to the unsubstituted portion of the DNA (-chain). The compound can thus be used for the preferential cleavage of a phosphodiester bond in a specific position of RNA. Accordingly, the invention provides a useful means for preparing, for instance, a deletion mutant. There is also disclosed a mixed oligomer which comprises an oligomer of RNA or a derivative thereof and a DNA oligomer, wherein the RNA oligomer or a derivative thereof is conjugated to the DNA oligomer via a phosphate diester linkage between the 5'-hydroxyl group and the 3'-hydroxyl group in the ribose or deoxyribose moiety. There is further disclosed a nucleoside derivative of a given general formula for use as a starting material.

Compounds for the cleavage at a specific position of RNA, oligomers

Purine-arabinosides and a method for making purine-arabinosides are disclosed. The method comprises contacting an arabinose donor and a purine source in the presence of an effective amount of enzyme produced by a bacterium and capable of transarabinosylation from the arabinose donor to the purine source, whereby a 9-(.beta.-D-arabinofuranosyl)-purine is produced.

Method for producing purine arabinosides

5-Fluorouraacil is produced by reacting orotic acid with a fluorinating agent and then, decarboxylating the resulting 5-fluoro-orotic acid.

Process for producing 5-fluorouracil

Growing community of inventors

Kawasaki, Japan

Hirokazu Morisawa