ANALYSIS OF PRODUCTS FROM PERIODATE OXIDATION AND FROM METHYLATION OF A RHAMNAN

1965 ◽  
Vol 43 (6) ◽  
pp. 1738-1745 ◽  
Author(s):  
G. G. S. Dutton ◽  
A. M. Unrau
Keyword(s):  
Vapor Phase ◽  
Paper Chromatography ◽  
Periodate Oxidation ◽  
Trimethylsilyl Ethers ◽  
Model Substance ◽  
Terminal Units

A synthetic L-rhamnan containing both rhamnofuranosyl and rhamnopyranosyl units has been used as a model substance in the application of vapor phase chromatography (v.p.c.) to the study of the structure of rhamnose containing polysaccharides. Groups of isomeric methylated sugars obtained from the methylated rhamnan were analyzed by converting them to methylated alditols which had widely different retention times. A Smith periodate degradation of the rhamnan gave 1,2-dihydroxypropane, 1-deoxy-D-erythritol, L-rhamnose, and 5-deoxy-L-arabinose, which were separated by paper chromatography. There were also obtained l-deoxy-3-O-(α-L-rhamnopyranosyl)-D-erythritol and the β-anomer, and 1-deoxy-2-O-(L-rhamnopyranosyl)-D-erythritol, separable by v.p.c. as their trimethylsilyl ethers. 1-Deoxy-D-erythritol was synthesized and characterized as the tri-p-nitrobenzoate. Of the terminal units in the synthetic rhamnan 35% were furanose and 2,3-di-O-methyl-L-rhamnose constituted 75% of the dimethyl fraction indicating that the principal linkage was (1 → 4).

THE STRUCTURE OF A SYNTHETIC ARABINAN

1965 ◽  
Vol 43 (4) ◽  
pp. 924-927 ◽  
Author(s):  
G. G. S. Dutton ◽  
A. M. Unrau
Keyword(s):  
Vapor Phase ◽  
Paper Chromatography ◽  
Methyl Ether ◽  
Periodate Oxidation ◽  
Borohydride Reduction ◽  
Terminal Units ◽  
Branched Structure ◽  
Hydrolysis Of

Hydrolysis of the fully methylated synthetic arabinan showed it to have a highly branched structure in which about 16% of the terminal units were furanose and 2,3-di-O-methyl-L-arabinose was the principal di-O-methyl ether. A method has been developed whereby mixtures of isomeric di- or mono-O-methyl arabinoses may be qualitatively analyzed by successive borohydride reduction, periodate oxidation, and borohydride reduction. The resulting fragments may be separated directly by vapor phase chromatography or by paper chromatography after demethylation.

THE WATER-SOLUBLE POLYSACCHARIDES OF DERMATOPHYTES: IV. GALACTOMANNANS I FROM TRICHOPHYTON GRANULOSUM, TRICHOPHYTON INTERDIGITALE, MICROSPORUM QUINCKEANUM, TRICHOPHYTON RUBRUM, AND TRICHOPHYTON SCHÖNLEINII

1965 ◽  
Vol 43 (1) ◽  
pp. 30-39 ◽  
Author(s):  
C. T. Bishop ◽  
M. B. Perry ◽  
F. Blank ◽  
F. P. Cooper
Keyword(s):  
Aqueous Solutions ◽  
Copper Complexes ◽  
Trichophyton Rubrum ◽  
Periodate Oxidation ◽  
Structural Features ◽  
Water Soluble ◽  
Major Constituent ◽  
Branch Points ◽  
Terminal Units ◽  
Hydrolysis Of

A group of polysaccharides, called galactomannans I, were precipitated as their insoluble copper complexes from aqueous solutions of the crude polysaccharides obtained from each of the organisms designated in the title. The five galactomannans I were homogeneous under conditions of electrophoresis and ultracentrifugation and had high positive specific rotations. The major constituent monosaccharide was D-mannose; amounts of D-galactose ranged from nil for the polysaccharide from T. rubrum to 13% for that from T. schönleinii. Methylation and hydrolysis of the five galactomannans I yielded varying amounts of the following: 2,3,5,6-tetra-O-methyl-D-galactose (not present in the products from T. rubrum), 2,3,4,6-tetra-O-methyl-D-mannose, 2,3,4-tri-O-methyl-D-mannose, 2,4,6-tri-O-methyl-D-mannose, 3,4-di-O-methyl-D-mannose, and 3,5-di-O-methyl-D-mannose. Periodate oxidation results agreed with the methylation studies. The gross structural features of each galactomannan I appear to be the same, namely, a basic chain of 1 → 6 linked α-D-mannopyranose units for approximately every 22 of which there is a 1 → 3 linked α-D-mannopyranose residue. Branch points occur along the 1 → 6 linked chain at the C2 positions of the D-mannopyranose units and once in every 45 units at the C2 position of a 1 → 6 linked D-mannofuranose residue. The D-galactose in the polysaccharides is present exclusively as non-reducing terminal furanose units; non-reducing terminal units of D-mannopyranose are also present. The variations in the identities and relative amounts of the non-reducing terminal units were the only apparent differences in the gross structural features within this group of polysaccharides.

THE GAS-LIQUID CHROMATOGRAPHY OF STEROID FORMATES; AN APPLICATION IN CONGENITAL ADRENAL HYPERPLASIA

1970 ◽  
Vol 47 (1) ◽  
pp. 55-64 ◽  
Author(s):  
H. L. J. MAKIN
Keyword(s):  
Liquid Chromatography ◽  
Periodate Oxidation ◽  
Oxygenation Index ◽  
Rapid Screening ◽  
Gas Liquid Chromatography ◽  
Adrenal Hyperplasia ◽  
Trimethylsilyl Ethers ◽  
Rapid Screening Test ◽  
Speed Up ◽  
Urinary Steroid

SUMMARY The gas-liquid chromatography (GLC) of some C19 steroid formates has been investigated in an attempt to speed up the final stages of the estimation of the 11-oxygenation index. SE-30 was found to give the best separation of the urinary C19 steroids formed after borohydride reduction and periodate oxidation of urine. Formates, acetates, propionates, n-butyrates, valerates and trimethylsilyl ethers were examined; formate esters gave the best separation of androsterone and aetiocholanolone. Estimation of the 11-oxygenation index by GLC increases the specificity and speed of single estimations and it is suggested that this method may find use as a rapid screening test for abnormal urinary steroid patterns.

CONSTITUTION OF A GLUCOMANNAN FROM JACK PINE (PINUS BANKSIANA, LAMB)

1960 ◽  
Vol 38 (6) ◽  
pp. 793-804 ◽  
Author(s):  
C. T. Bishop ◽  
F. P. Cooper
Keyword(s):  
Pinus Banksiana ◽  
Group Analysis ◽  
Periodate Oxidation ◽  
Jack Pine ◽  
Degree Of Polymerization ◽  
Molar Ratio ◽  
Partition Chromatography ◽  
Pine Wood ◽  
Terminal Units ◽  
End Group

A hemicellulose fraction from jack pine wood has been shown to contain D-mannose, D-glucose, and D-galactose in a molar ratio of 49:17:2. The glucomannan was electrophoretically homogeneous and showed a degree of polymerization of 18–21 by three different methods of end group analysis. Methylation and hydrolysis yielded the following O-methyl ethers: 2,3,4,6-tetra-O-methyl-D-glucose (2.8 moles); 2,3,4,6-tetra-O-methyl-D-galactose (1 mole); 2,3,6-tri-O-methyl-D-mannose (52 moles); 2,3,6-tri-O-methyl-D-glucose (15.3 moles); di-O-methyl-D-glucose (1 mole); di-O-methyl-D-galactose (2 moles). Lack of survival of any monosaccharides in the periodate-oxidized glucomannan showed that there was no branching through C2 or C3 of any of the units. Gas–liquid partition chromatography was used to analyze products from methylation and hydrolysis and from periodate oxidation and reduction of the polysaccharides. The results showed that the glucomannan from jack pine was composed of 1 → 4 linked β-D-mannose and β-D-glucose residues with D-galactose residues present as non-reducing terminal units. Branching, if any, must occur through C6 of units making up the polysaccharide. This structure is compared with those of glucomannans found in other soft woods.

QUANTITATIVE ISOLATION AND ASSAY OF NEUTRAL GLYCERIDE GLYCEROL AND PHOSPHOGLYCERIDE GLYCEROL

1964 ◽  
Vol 42 (2) ◽  
pp. 195-202 ◽  
Author(s):  
A. S. W. DeFreitas ◽  
Florent Depocas
Keyword(s):  
Paper Chromatography ◽  
Specific Activity ◽  
Periodate Oxidation ◽  
Chromotropic Acid ◽  
Sodium Borate ◽  
Carbon 14 ◽  
Acid Catalyzed ◽  
Radioactivity Measurements

Neutral glyceride glycerol and phosphoglyceride glycerol obtained by acid-catalyzed methanolysis of 10-100 mg quantities of mixed lipids are separated by paper chromatography. Quantitative elution of the compounds is followed by a periodate oxidation – chromotropic acid assay of the released formaldehyde. Application of this method to the assay of carbon-14-labelled material permits accurate specific activity determinations by radioactivity measurements on phosphoglycerol and on glycerol complexed with sodium borate.

CONSTITUTION OF A SYNTHETIC GLUCAN: III. PERIODATE OXIDATION

1964 ◽  
Vol 42 (9) ◽  
pp. 2048-2055 ◽  
Author(s):  
G. G. S. Dutton ◽  
A. M. Unrau
Keyword(s):  
Ion Exchange ◽  
Vapor Phase ◽  
Degradation Products ◽  
Periodate Oxidation ◽  
Ion Exchange Resins ◽  
Mild Acid Hydrolysis ◽  
Trimethylsilyl Derivatives ◽  
Exchange Resins ◽  
First Time ◽  
Mild Acid

A synthetic glucan known to contain D-glucofuranose and D-glucopyranose units was subjected to a Smith periodate degradation. After mild acid hydrolysis any aldehydic compounds were oxidized with bromine and the neutral fragments separated from the acidic by ion exchange resins. The acidic portion, after lactonization and reduction, gave glycerol and a series of oligosaccharides. The neutral portion was resolved into glycerol, erythritol, and a series of seven fractions containing glycosides with degrees of polymerization up to eight. Each fraction which was homogeneous by paper chromatography contained at least two components. Some of these individual components were separated as their trimethylsilyl derivatives by vapor phase chromatography and the following glycosides were identified: 1-O-(α-D-glucopyranosyl)-glycerol, 1-O-(β-D-glucopyranosyl)-glycerol, 2-O-(D-xylofuranosyl)-D-erythritol, 2-O-(α-D-glucopyranosyl)-D-erythritol, 2-O-(β-D-glucopyranosyl)-D-erythritol, 1-O-(D-glucopyranosyl)-erythritol. These results demonstrate for the first time the separation of Smith degradation products by vapor phase chromatography. The presence in the polysaccharide of α and β linkages and the existence of D-glucofuranose residues are confirmed. The highly branched nature of the polymer is shown by the fact that four successive periodate oxidations and mild hydrolyses were necessary to oxidize all the hexose units.

A METHOD FOR THE IDENTIFICATION OF THE MONO-O-METHYLGLUCOSES

1953 ◽  
Vol 31 (9) ◽  
pp. 814-820 ◽  
Author(s):  
R. U. Lemieux ◽  
H. F. Bauer
Keyword(s):  
Paper Chromatography ◽  
Sodium Borohydride ◽  
Alkaline Hydrolysis ◽  
Periodate Oxidation ◽  
Methyl Cellulose ◽  
Water Soluble ◽  
The Other ◽  
Potential Value ◽  
Hydrolysis Of

Periodate oxidation of any one mono-O-methylglucopyranose and alkaline hydrolysis of the product yields a substance which can be positively distinguished by paper chromatography from the products formed under the same conditions from the other mono-O-methylglucopyranoses. Thus, the components of a mixture of the mono-O-methylglucopyranoses can be readily identified. The method appears useful for the identification of di-O-methylglucoses. Reduction with sodium borohydride prior to periodate oxidation renders the method useful for the identification of tri-O-methylglucoses. The potential value of the method, which can be used on a microscale, is illustrated by an application to the characterization of the O-methylglucoses derived from a water-soluble O-methyl-cellulose

Cytochemical Studies of Cell Wall Biosynthesis in Staphylococcus Aureus

1972 ◽  
Vol 30 ◽  
pp. 328-329
Author(s):  
Masaatsu Koike ◽  
Koichi Nakashima ◽  
Kyoko Iida
Keyword(s):  
Staphylococcus Aureus ◽  
Periodate Oxidation ◽  
Early Time ◽  
The Other ◽  
Penicillin G ◽  
Cell Wall Biosynthesis ◽  
Septal Wall ◽  
Peptidoglycan Biosynthesis ◽  
Gram Positive Bacteria ◽  
Cross Linkage

Penicillin exerts the activity to inhibit the peptide cross linkage between each polysaccharide backbone at the final stage of wall-peptidoglycan biosynthesis of bacteria. Morphologically, alterations of the septal wall and mesosome in gram-positive bacteria, which were occurred in early time after treatment with penicillin, have been observed. In this experiment, these alterations were cytochemically investigated by means of silver-methenamine staining after periodate oxidation, which is applied for detection of localization of wall mucopolysaccharide.Staphylococcus aureus strain 209P treated with 100 u/ml of penicillin G was divided into two aliquotes. One was fixed by Kellenberger-Ryter's OSO4 fixative at 30, 60 and 120 min after addition of the antibiotic, dehydrated through alcohol series, and embedded in Epon 812 (Specimen A). The other was fixed by 21 glutaraldehyde, dehydrated through glycolmethacrylate series and embedded in glycolmethacrylate mixture, according to Bernhard's method (Specimen B).

Planar defects in ordered (Ga,In)P

1988 ◽  
Vol 46 ◽  
pp. 902-903
Author(s):  
S. McKernan ◽  
C. B. Carter ◽  
D. Bour ◽  
J. R. Shealy
Keyword(s):  
Electron Diffraction ◽  
Vapor Phase ◽  
Growth Direction ◽  
High Density ◽  
Ordered Structure ◽  
Planar Defects ◽  
Diffraction Patterns ◽  
Ternary Semiconductors ◽  
Anion Species ◽  
Metallic Vapor

The growth of ternary III-V semiconductors by organo-metallic vapor phase epitaxy (OMVPE) is widely practiced. It has been generally assumed that the resulting structure is the same as that of the corresponding binary semiconductors, but with the two different cation or anion species randomly distributed on their appropriate sublattice sites. Recently several different ternary semiconductors including AlxGa1-xAs, Gaxln-1-xAs and Gaxln1-xP1-6 have been observed in ordered states. A common feature of these ordered compounds is that they contain a relatively high density of defects. This is evident in electron diffraction patterns from these materials where streaks, which are typically parallel to the growth direction, are associated with the extra reflections arising from the ordering. However, where the (Ga,ln)P epilayer is reasonably well ordered the streaking is extremely faint, and the intensity of the ordered spot at 1/2(111) is much greater than that at 1/2(111). In these cases it is possible to image relatively clearly many of the defects found in the ordered structure.

Multiple phase transitions investigated by high-speed TEM

1990 ◽  
Vol 48 (4) ◽  
pp. 550-551
Author(s):  
Oleg Bostanjoglo ◽  
Peter Thomsen-Schmidt
Keyword(s):  
Phase Transitions ◽  
High Speed ◽  
Short Exposure ◽  
Semiconductor Film ◽  
Time Resolved ◽  
Short Exposure Time ◽  
Multiple Phase ◽  
Model Substance ◽  
History Of ◽  
Electron Image

Thin GexTe1-x (x = 0.15-0.8) were studied as a model substance of a composite semiconductor film, in addition being of interest for optical storage material. Two complementary modes of time-resolved TEM were used to trace the phase transitions, induced by an attached Q-switched (50 ns FWHM) and frequency doubled (532 nm) Nd:YAG laser. The laser radiation was focused onto the specimen within the TEM to a 20 μm spot (FWHM). Discrete intermediate states were visualized by short-exposure time doubleframe imaging /1,2/. The full history of a transformation was gained by tracking the electron image intensity with photomultiplier and storage oscilloscopes (space/time resolution 100 nm/3 ns) /3/. In order to avoid radiation damage by the probing electron beam to detector and specimen, the beam is pulsed in this continuous mode of time-resolved TEM,too.Short events ( <2 μs) are followed by illuminating with an extended single electron pulse (fig. 1c)

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