1.Stimuli-responsive spherical brushes based on D-galactopyranose and 2-(dimethylamino)ethyl methacrylate.
Arslan H1, Pfaff A, Lu Y, Stepanek P, Müller AH. Macromol Biosci. 2014 Jan;14(1):81-91. doi: 10.1002/mabi.201300290. Epub 2013 Sep 17.
Stimuli-responsive spherical brushes composed of 6-O-methacryloyl-1,2:3,4-di-O-isopropylidene-D-galactopyranose (MAIGal) and 2-(dimethylamino)ethyl methacrylate (DMAEMA) are prepared via atom transfer radical polymerization (ATRP) using cross-linked polystyrene nanoparticles covered with a thin layer of 2-(2-bromoisobutyryloxy)ethyl methacrylate (BIEM) as ATRP initiator by the "grafting from" approach. The stimuli-responsive behavior of the deprotected spherical PMAGal-b-PDMAEMA block copolymer brushes is investigated by dynamic light scattering and cryogenic transmission electron microscopy. A brush with arms containing 160 MAGal and 170 DMAEMA monomer units shows a significant contraction of the hydrodynamic radius from 20 to 70 °C at pH = 8 with a cloud point at ≈40 °C, whereas no LCST is detected at pH = 6 and 7 due to the protonation of the DMAEMA units. Aggregates occur at low temperatures and pH 8 due to intermolecular interactions between the chains of different brushes, which disappear above LCST, when the PDMAEMA chains fold back to the core of the brushes, exposing the glycopolymer chains to the outside.
2.Preparation of some (1 goes to 6)-linked disaccharides, and their derivatives suitable for protein modification.
Lee RT, Lee YC. Carbohydr Res. 1982 Feb 16;101(1):39-47.
Synthetic methods for the preparation of per-O-acetylated, (1 goes to 6)-linked disaccharides containing either a D-galactose or a D-glucose residue at the reducing end are described. In these methods, 1,2,3,4-tetra-O-acetyl-6-O-trityl-beta-D-glucopyranose was first converted into 1,2,3,4-tetra-O-acetyl-beta-D-glucopyranose (1) by rapid treatment with 90% trifluoroacetic acid, followed by rapid isolation designed to minimize O-acyl migration. Disaccharides acid, followed by rapid isolation designed to minimize )-acyl migration. Disaccharides were formed by glycosylation of 1 or 1,2:3,4-di-O-isopropylidene-D-galactopyranose with per-O-acetylglycosyl halides. Isopropylidene groups in the resulting disaccharide, if present were removed, and the disaccharide was per-O-acetylated. Per-O-acetylated beta-Gal-(1 goes to 6)-Glc and beta-GlcNAc-(1 goes to 6)-Gal, and a mixture of per-O-acetylated alpha-Gal-(1 goes to 6)-Gal and beta-Gal-(1 goes to 6)-Gal (in the ratio of 3:7) were thus obtained.
3.Synthesis of amphiphilic galactopyranosyl diamines and amino alcohols as antitubercular agents.
de Almeida MV1, Le Hyaric M, Amarante GW, Silva Lourenço MC, Lima Brandão ML. Eur J Med Chem. 2007 Aug;42(8):1076-83. Epub 2007 Jan 25.
Mono- and diacylated derivatives of galactopyranosyl amines were obtained from d-galactose, via aminated intermediates prepared by reaction of 6-deoxy-6-iodo-1,2:3,4-di-O-isopropylidene-alpha-d-galactopyranose with 1,3-propanediamine, 1,2-ethanediamine or ethanolamine. Monoacylated derivatives displayed antitubercular activity.
4.Novel perfluoroalkylated derivatives of D-galactopyranose and xylitol for biomedical uses. Hemocompatibility and effect on perfluorocarbon emulsions.
Církva V1, Polák R, Paleta O, Kefurt K, Moravcová J, Kodícek M, Forman S. Carbohydr Res. 2004 Sep 13;339(13):2177-85.
6-O-(4,4,5,5,6,6,7,7,7-Nonafluoro-2-hydroxyheptyl)-, 6-O-(4,4,5,5,6,6,7,7,8,8,9,9,9-tridecafluoro-2-hydroxynonyl)-, and 6-O-(4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-heptadecafluoro-2-hydroxyundecyl)-d-galactopyranose (9, 10, and 11, resp.) were prepared by a two-step synthesis including the reaction of 1,2:3,4-di-O-isopropylidene-alpha-d-galactopyranose with 2-[(perfluoroalkyl)methyl]oxiranes under catalysis with BF(3).Et(2)O. Similarly, 1-O-(4,4,5,5,6,6,7,7,7-nonafluoro-2-hydroxyheptyl)-, 1-O-(4,4,5,5,6,6,7,7,8,8,9,9,9-tridecafluoro-2-hydroxynonyl)-, 1-O-(4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-heptadecafluoro-2-hydroxyundecyl)-dl-xylitol (18, 19, and 20, resp.) were prepared by a two-step synthesis from the corresponding 1,2:3,4-di-O-isopropylidene-dl-xylitol. Most of the both types of fluoroalkylated carbohydrate derivatives 9-11 and 18-20 generally displayed very low level of hemolytic activity and excellent co-emulsifying properties on testing on perfluorodecalin-Pluronic F-68 microemulsions.