NEO-AMYLOPECTINYL MODELS SYNTHESIS OF
COMPLEX BETA-BRANCHED
MALTO-OLIGOSACCHARIDES IN SOLUBLE AND
SOLID PHASE

Christophe Bliard, Virginie Glaçon

► To cite this version:

Christophe Bliard, Virginie Glaçon. NEO-AMYLOPECTINYL MODELS SYNTHESIS OF COMPLEX BETA-BRANCHED MALTO-OLIGOSACCHARIDES IN SOLUBLE AND SOLID PHASE. 1st European Chemistry Congress, Aug 2006, Budapest, Hungary. , 2006. [arXiv:0602.4189]

HAL Id: hal-02328669

https://hal.science/hal-02328669

Submitted on 23 Oct 2019

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
# NEO-AMYLOPECTINYL MODELS
## SYNTHESIS OF COMPLEX BETA-BRANCHED MALTO-OLIGOSACCHARIDES IN SOLUBLE AND SOLID PHASE.

<figure><img src="image_2.png" /></figure>

Christophe BLIARD & Virginie GLAÇON

<figure><img src="image_3.png" /></figure>

FRE 2715 CNRS, UFR Sciences, bâtiment 18 Europol'Agro, Moulin de la Housse, BP 1039, 51687 Reims cedex 2

Tel: 03 26 91 34 95 / Fax : 03 26 91 35 96 / christophe.bliard@univ-reims.fr

<figure><img src="image_4.png" /></figure>

CENTRE NATIONAL
DE LA RECHERCHE
SCIENTIFIQUE

<figure><img src="image_5.png" /></figure>

EUROPOL'
AGRO

### Abstract:

Starch is the ubiquitous glucidic reserve compound in nature. Synthesized by most plants from solar energy it is easily produced in very large scale cultures (cereals, tubers, legumes...). Besides its irreplaceable position in the food chain Starch is also a widely used commodity for its non-alimentary properties (paper, textile industry, adhesive, gels...) in almost all human activities¹. Though the polysaccharidic nature and the basic structure : polya(1-4) glucopyrannose of its minor constituent Amylose, and α(1-6) branched α(1-4) polyglucopyrannose of the major amylopectin has long been known, to date, the fine primary structure of the former still remains to be described ! The branching pattern found in amylopectin can reach extreme complexity. The determination of amylopectins' primary structures from various botanical origins families can be a real challenge. Moreover, though the enzymes involved in starch synthesis have been well-described², no satisfactory in-vitro synthesis has been achieved to date, one of the reasons invoked being the lack of proper primer substrate³. In this paper we present an investigation of such structural diversity by re-building well-defined branched malto-oligosaccharidic model structures through chemical hemisynthesis, in order to obtain such substrates. Several isoamylase resistant, beta-branched neo-amylopectinyl oligosaccharides having degrees of polymerisation (DP) 4 to 8, with well-defined structures, were obtained. The construction of these models was performed using chemically modified malto-oligosaccharides in solution. All structures were confirmed by long distance heteronuclear NMR spectroscopy. Using activated Wang resin, solid-phase supported oligosaccharides were synthesised and the structures analysed by HR-MAS NMR.

1. Sicard P.J. *L'actualité chimique* 11-12 (2002) 23-26

2. Buléon A., Colonna P., Planchot V., Ball S., Int. J. Biol. Macromolecules, 23, (1998) 85-112.

3. Ball S. et al., Cell, 86(1996)349-352

<figure><img src="image_6.png" /></figure>

### Oligosaccharide Syntheses :

The model oligosaccharides, chosen as targets were the neo-amylopectines β-branched analogs. Retro-synthesis analysis showed the possibility a fast, flexible and easy access of a large variety of well defined specific branched structures of DP 3 to 9 from maltose and maltotriose in 7 to 11 steps. Oligosaccharides up to DP 8 branched neo-amylopectinyl models were synthesized from common activated substrates on selectively protected di- and trisaccharide derivatives. These derivatives are destined :

* to enzymatic test on starch synthetases and hydrolases in order to study biosynthesis and biodegradation

* to serve as RMN structure references in the analysis of limit dextrines from amylopectine enzymatic degradation

* to serve as reference in structural analysis (influence of parameters such as inter-branched chain distances).

<figure><img src="image_7.png" /></figure>

<figure><img src="image_8.png" /></figure>

<figure><img src="image_9.png" /></figure>

<figure><img src="image_10.png" /></figure>