Raphael Thomas

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Benzyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-alpha-D-glucopyranoside was converted into its 4-O-(methylsulfonyl) derivative (2) by treatment with methanesulfonyl chloride in pyridine. Displacement of the methylsulfonyloxy group of 2 with fluoride ion afforded benzyl 2-acetamido-3,6-di-O-benzyl-2,4-dideoxy-4-fluoro-alpha-D-galactopyranosi de, which on(More)
Several physical and chemical parameters of angiotensin-converting enzyme (ACE) were determined using a spectrophotometric assay of gill tissue homogenates from rainbow trout. This assay is based on the evolution of free hippuric acid via enzymatic cleavage of histidyl-leucine from the synthetic substrate hippuryl-l-histidyl-l-leucine (HHL). Piscine ACE(More)
Benzyl 2-acetamido-6-O-(2-acetamido-2-deoxy-4,6-O-isopropylidene-beta-D- glucopyranosyl)-2-deoxy-3,4-O-isopropylidene-alpha-D-galactopyranoside (2) was obtained by acetalation of its parent disaccharide with 2,2-dimethoxypropane in hot N,N-dimethylformamide and in the presence of 4-toluenesulfonic acid. Glycosylation of 2 with(More)
To meet the increasing demand of high performance filters in GHz radio communication systems, we have improved the design techniques and fabrication processes for SAW devices. The standard optical projection printing technique based on i-line lithography used for mass-production was optimized, thus attaining a linewidth of 0.3 microns. As a first SAW device(More)
Condensation of 3-O-(2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-beta-D- glucopyranosyl)-2,4,6-tri-O-acetyl-alpha-D-galactopyranosyl bromide (1) with benzyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-alpha-D-glucopyranoside in boiling benzene and in the presence of mercuric cyanide afforded a trisaccharide that was O-deacetylated to give benzyl(More)
Treatment of benzyl 2-acetamido-2-deoxy-alpha-D-galactopyranoside with 4-methoxybenzaldehyde dimethyl acetal in N,N-dimethylformamide in the presence of 4-toluenesulfonic acid afforded the 4,6-O-(4-methoxybenzylidene) acetal, which was glycosylated with 2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosyl bromide (1). Reductive ring-opening of the acetal group(More)
Liquid chromatography under elevated pressure (l.c.) was employed for the separation of some benzyl and nitrophenyl glycosides of a variety of mono-, di-, tri-, and tetra-saccharides. The separation was conducted on a Waters Carbohydrate Analysis column by use of a mixture of acetonitrile-water as the mobile phase. In general, monosaccharides emerged first(More)