Synthesis of lentinan core fragment trisaccharide, tetrasaccharide, hexasaccharide and heptasaccharide

Abstract

A synthesis method of lentinan core fragments trisaccharide, tetrasaccharide, hexasaccharide and heptasaccharide includes the following steps: using trichloro-acetyliminoester of acyl glucose or its halogenated compound as glycosyl donor, using 1,2:5,6-di-O-isopropylidene glucose as glycosyl receptor, firstly obtaining 1,3-beta-connected disaccharide, selective hydrolysis to remove 5,6-O-isopropylidene to oblain the disaccharide whose 5,6 position is free hydroxyl disaccharide, then using the obtained disaccharide as receptor, using trichloro-acetyliminoester of acyl glucose or its halogenated compound as glycosyl donor, making coupling reaction to obtain trisaccharide, hydrolyzing said trisaccharide under the acid condition, making acetylation, selectively removing acetyl group of 1-position, activating to obtain non-reducing end trisaccharide donor, then using similar method to synthesize reducing end trisaccharide receptor of glucose whose 3-position is free hydroxyl glycose, coupling trisaccharide donor and receptor, removing protection to obtain hexasaccharide, using similar method to obtain heptasaccharide.

Description

technical field [0001] The present invention relates to biological activity, especially relates to trisaccharides of the core fragment trisaccharides of citrus polysaccharides that may be used as medicine, starting from 1,2:5,6-di-O-isopropylidene glucose, Synthesis of tetrasaccharides, hexasaccharides, and heptasaccharides. Background technique [0002] According to current knowledge, polysaccharides are mostly used to enhance animal immunity, such as polysaccharides extracted from practical bacteria such as lentinan and ganoderma lucidum polysaccharides, or polysaccharides extracted from Chinese herbal medicines. There are not many oligosaccharides that have been studied clearly and have clear immune activity, such as 1,3-α-linked mannan oligosaccharides, 1,3-β-linked glucose oligosaccharides, etc. However, whether it is extracted from natural products, isolated, or oligosaccharides synthesized with great effort, its efficacy has not reached as high as plant self-defense ...

AI Technical Summary

Problems solved by technology

[0003] Repeating unit of Ientinan heptascharide Due to the different structures of oligosaccharides of antigens associated with different diseases, it is still not easy to synthesize some oligosaccharides by existing methods

So far, there has been no report on the synthesis of oligosaccharide repeating units of lentinan