Other

Wako Pure Chemical Industries, Inc.

The Nisshin Oil Mills, Ltd.

Japan Science and Technology Agency

Toyota Boshoku Kabushiki Kaisha

Japan Tobacco Inc.

Otsuka Pharmaceutical Company, Limited

Kanebo, Limited

Nippon Shinyaku Company, Ltd.

Toho Yakuhin Kogyo Kabushiki Kaisha

Akira Hasegawa

Makoto Kiso

Hideharu Ishida

Hiroshi Ueda

Yoshiaki Yoshikuni

Shinji Satomura

Yutaka Saito

Kazuyuki Morihara

Masanobu Suzuki

Shinichi Uesato

Tomio Ishida

Hiromune Ando

Akihiro Imamura

Seiichi Kitamura

Yukihiro Isogai

An &#x3b1;-selective glycosylation process of a glycosylation reaction between a sugar structure of hexose or an aldose having a chain with six or more carbon atoms in the molecule, which is a monosaccharide or a reducing end of an oligosaccharide with two or more monosaccharide residues connected by glycosidic linkages (an oligosaccharide with two monosaccharide residues is disaccharide) (also referred to as 'a disaccharide to an oligosaccharide') or a sugar chain and alcoholic hydroxyl group or thiol group, to obtain a sugar structure glycoside containing &#x3b1;-glycoside at a high ratio, under the ring-shaped formation of a protective group in a silyl acetal structure over hydroxyl groups at positions 4 and 6 in the sugar structure. By the process, highly selective &#x3b1;-glycosylation of sugar structure can be progressed in a simple and efficient manner.

Method of &#x3b1;-selective glycosylation

Carboxymethylgalactose derivatives

The invention provides important intermediate compounds for the synthesis of acidic glycolipids which are identical with the glycolipid antigens isolated from the acidic glycolipid fractions of peripheral nerve and embryonic central nervous system and preparation methods thereof. By the adoption of the present intermediate compounds, sulfation of 3-hydroxyl group of end glucuronic acid portion of the acidic glycolipid can be quite easily carried out and total synthetic yield be greatly improved.

Intermediate compounds for the synthesis of glycolipids

Novel glycolipid derivatives of Formula (I): ##STR1## wherein R is a long chain alkyl, or their salts are disclosed. These compounds act as a ligand for selectin family and exhibit a remarkable inhibitory effect on the binding of selectin family to its native ligand sialyl Lewis.sup.x.

Glycolipid derivatives acting as ligands for selectins

Lewis-type sugar chain derivative

Disclosed are ganglioside GM.sub.3 analogs represented by the formula ##STR1## in which X represents a radical of the following formula ##STR2## wherein at least one of R.sub.1, R.sub.2, R.sub.3 and R.sub.4 is hydrogen and the remainder is hydroxyl; ##STR3## wherein at least one of R.sub.5 and R.sub.6 is hydrogen and the remainder is methyl; ##STR4## wherein m is an integer of 15 to 25, l is an integer of 0 to 3, n is an integer of 11 to 15 and Ac represents acetyl. The ganglioside GM.sub.3 analogs are expected to possess an inhibitory activity for influenza virus.

Ganglioside GM3 analogs

Disclosed are thioglycoside analogs of gangliosides represented by the formula ##STR1## in which Y represents a radical of the following formula ##STR2## and X represents a radical of the formula ##STR3## wherein m is an integer of 15 to 25, l is an integer of 0 to 3 and n is an integer of 11 to 15. The thioglycoside analogs are expected to exert specific enzyme-inhibitory effects.

Thioglycoside analogs of gangliosides

An oligosaccharide derivative of the formula: ##STR1## wherein R is --SR.sup.2, ##STR2## R.sup.1 is an optically detectable group, etc.; R.sup.2 is alkyl or substituted alkyl; and n is zero or 1-5, is effective as a substrate for measuring .alpha.-amylase activity and can be synthesized easily in high yield.

Oligosaccharide derivatives suitable for .alpha.-amylase determination

Lipid A monosaccharide analogues

The present invention provides a novel process for producing gangliosides such as GM.sub.3 and GM.sub.4 and analogues thereof. This process has the excellent characteristics in that in introduction of ceramide into sialooligosaccharides, first an azidosphingosine derivative is introduced and then the azido portion is reduced to effect N-acylation. The present invention has a conspicuous effect in that the yield is markedly improved as compared with conventional processes.

Process for producing gangliosides

The present invention provides a process for selective production of a 2-.alpha.-O-glycoside compound of sialic acid which is useful as a starting material or intermediate for medicines and biochemical reagents. The process comprises reacting an alkylthiosialic acid derivative represented by the formula [I]: ##STR1## wherein R represents an acyl group and R.sup.1 and R.sup.2 each represents a lower alkyl group with a compound having alcoholic hydroxyl group at a low temperature in a polar solvent having no hydroxyl group in the presence of a Lewis acid selected from the group consisting of methyl triflate, trimethylsilyl triflate and dimethyl(methylthio)sulfonium triflate. The present invention further provides novel compounds.

Process for producing sialic acid derivatives

Provided herein is a derivative of 2-deoxy-2-amino-4-O-phophono-D-glucopyranose, which is derived from lipid A, of the formula: ##STR1## wherein R.sub.1 and R.sub.2 are a member in a pair selected from the group consisting of those indicated in a following table:

Analogs of nonreducing monosaccharide moiety of lipid A

Growing community of inventors

Gifu, Japan

Makoto Kiso