- Synthesis of α-D-glucopyranosyl-(1-3)-α-D-mannopyranosyl-(1-7)-4- methylumbelliferone, a fluorogenic substrate for endo-α-1,2-mannosidase
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α-D-Glucopyranosyl-(1-3)-α-D-mannopyranosyl-(1-7)-4- methylumbelliferone (Glc-Man-Muf) was synthesized as a potential fluorogenic substrate for endo-α-1,2-mannosidase. The synthesis was designed in a convergent way. The glucose donor ethyl 2,3,4,6-tetra-O-benzyl-1-thio-β-glucopyranoside and the mannose acceptor 1,2:4,6-di-O-isopropylidene-β-D-mannopyranose were coupled in the presence of N-iodosuccinimide and trifluoromethane-sulfonic acid to yield the corresponding disaccharide derivative. After conversion into peracetylated α-D-glucopyranosyl-(1-3)-α-D-mannopyranose the disaccharide was attached to 4-methylumbelliferone using the Helferich method. After separation of the desired isomer, deacetylation yielded the title compound. Glc-Man-Muf was used as a substrate in endomannosidase assays with rat liver Golgi preparations as an enzyme source (in the presence of the α-glucosidase inhibitor deoxynojirimycin). The degradation of Glc-Man-Muf was linear with protein up to 300 μg and with time up to 2 h. Vmax and Km were determined to be 0.17 nmol/mg × h and 3.7 mM, respectively.
- Vogel,Pohlentz
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p. 1247 - 1258
(2007/10/03)
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- SYNTHESIS OF A PEPTIDYLDIMANNOSYL PHOSPHATE: FRAGMENT OF THE VARIANT-SPECIFIC SURFACE GLYCOPROTEIN MEMBRANE ANCHOR FROM TRYPANOSOMA BRUCEI
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Condensation of protected β-benzyl-aspartate 4 with 2-amino-ethanol, subsequent deprotection of the amino function and coupling with N,N'-di-benzyloxycarbonyl-lysine (7) afforded the peptidyl alcohol 8.Glycosylation of methyl 3,4,6-tri-O-benzyl-α-D-mannopyranoside (11) by ethyl 2,6-di-O-benzoyl-3,4-di-O-benzyl-1-thio-α-D-mannopyranoside (14) gave, after debenzoylation and protection of the 2'-hydroxyl function, the suitably protected dimannoside 21.Phosphitylation of 21 with benzyloxy-bis-(N,N-diisopropylamino)phosphine (18) followed by the addition of 8 gave, after oxidation and subsequent hydrogenolysis of the benzyl groups, the title compound in a good yield.
- Verduyn, R.,Belien, J. J. A.,Dreef-Tromp, C. M.,Marel, G. A. van der,Boom, J. H. van
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p. 6637 - 6640
(2007/10/02)
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- SYNTHESIS OF A MODEL OF AN IMMER CHAIN OF CELL-WALL PROTEOHETEROGLYCAN ISOLATED FROM Piricularia oryzae: BRANCHED D-MANNOPENTAOSIDES
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Efficient syntheses are described of the branched D-mannopentaosides methyl 2,6-di-O-(2-O-α-D-mannopyranosyl-α-D-mannopyranosyl)-α-D-mannopyranoside and methyl 2,4-di-O-(2-O-α-D-mannopyranosyl-α-D-mannopyranosyl)-α-D-mannopyranoside, starting from the gly
- Ogawa, Tomoya,Sasajima, Kikuo
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