Chemical synthesis of 6'-α-maltosyl-maltotriose, a branched oligosaccharide representing the branch point of starch

Article abstract of DOI:10.1016/0008-6215(95)00203-6

Chemical synthesis of the branched pentasaccharide 6'-α-maltosyl-maltotriose (15) is reported, based on the use of one synthon as a glycosyl acceptor and another synthon as a glycosyl donor. The synthon used as glycosyl acceptor was phenyl 2,3,6-tri-O-benzyl-1-thio-β-D-glucopyranoside (7) and was synthesized from D-glucose with phenyl 2,3-di-O-acetyl-4,6-O-benzylidene-1-thio-β-D-glucopyranoside and phenyl 2,3-di-O-benzyl-4,6-O-benzylidene-1-thio-β-D-glucopyranoside as key intermediates. The synthon used as glycosyl donor was O-(2,3,4,6-tetra-O-benzyl-α-D-glucopyranosyl)-(1 → 4)-O-(2,3,6-tri-O-benzyl-α-D-glucopyranosyl)-(1 → 6)-O-[(2,3,4,6-tetra-O-benzylα-D-glucopyranosyl)-(1 → 4)]-2,3-di-O-benzyl-α,β-D-glucopyranosyl trichloroacetimidate (12) and was synthesized from phenyl O-(2,3,4,6-tetra-O-benzyl-α-D-glucopyranosyl)-(1 → 4)-O-(2,3,6-tri-O-benzyl-α-D-glucopyranosyl)-(1 → 6)-O-[(2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl)(1 → 4)]-2,3-di-O-acetyl-1-thio-β-D-glucopyranoside with O-(2,3,4,6-tetra-O-benzyl-α-D-glucopyranosyl)-(1 → 4)-O-(2,3,6-tri-O-benzyl-α-D-glucopyranosyl)-(1 → 6)-O-[(2,3,4,6-tetra-O-benzyl-α-D-glucopyranosyl)-(1 → 4)]-2,3-di-O-benzyl-D-glucopyranose as an intermediate. Condensation of compounds 7 and 12 followed by removal of the phenylthio group and debenzylation provided the branched pentasaccharide 15. Alternatively, the branched pentasaccharide was produced from amylopectin by consecutive alpha- and beta-amylase treatments and purified by chromatography. The identity of the products obtained by chemical synthesis and enzymatic hydrolysis is documented by ¹H and ¹³C NMR spectra.

Full text of DOI:10.1016/0008-6215(95)00203-6

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Evaluation Only. Created with Aspose.PDF. Copyright 2002-2021 Aspose Pty Ltd.

Evaluation Only. Created with Aspose.PDF. Copyright 2002-2021 Aspose Pty Ltd.