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.

ChemInform Abstract: VAPOR-PHASE DEHYDRATION OF ISOPROPANOL ON MACROPOROUS ION EXCHANGE RESINS

1981 ◽  
Vol 12 (41) ◽  
Author(s):  
S. P. SIVANAND ◽  
B. V. KAMATH ◽  
R. S. SINGH ◽  
D. K. CHAKRABARTY
Keyword(s):  
Ion Exchange ◽  
Vapor Phase ◽  
Ion Exchange Resins ◽  
Exchange Resins

Interference by the 4-hydroxylated metabolite of propranolol with determination of metanephrines by the Pisano method.

1980 ◽  
Vol 26 (6) ◽  
pp. 776-777 ◽  
Author(s):  
D Chou ◽  
M Tsuru ◽  
J L Holtzman ◽  
J H Eckfeldt
Keyword(s):  
Ion Exchange ◽  
Periodate Oxidation ◽  
Ion Exchange Resins ◽  
Special Significance ◽  
High Ph ◽  
Exchange Resins ◽  
Hydroxylated Metabolite ◽  
Urinary Metanephrines

Abstract Measurements of urinary metanephrines by the Pisano procedure (Clin. Chim. Acta 5: 406, 1960) are unreliable in patients who are taking propranolol owing to the presence of 4-hydroxypropranolol in the urine. Three properties of this propranolol metabolite lead to interference: (a) it is absorbed and eluted from ion-exchange resins under the conditions Pisano used for metanephrine isolation, (b) at high pH it absorbs at 350 to 360 nm, and (c) it is oxidized by periodate to a substance with negligible absorption in this region. Because 350 to 360 nm is the wavelength used to quantitate vanillin, the product formed from periodate oxidation of metanephrines, and because the unoxidized eluate is used as a specimen blank, the presence of 4-hydroxypropranolol spuriously decreases the measured urinary metanephrines; this has special significance because patients being tested for increased metanephrines are also likely to be receiving propranolol for hypertension.

Interference by the 4-hydroxylated metabolite of propranolol with determination of metanephrines by the Pisano method.

1980 ◽  
Vol 26 (6) ◽  
pp. 776-777
Author(s):  
D Chou ◽  
M Tsuru ◽  
J L Holtzman ◽  
J H Eckfeldt
Keyword(s):  
Ion Exchange ◽  
Periodate Oxidation ◽  
Ion Exchange Resins ◽  
Special Significance ◽  
High Ph ◽  
Exchange Resins ◽  
Hydroxylated Metabolite ◽  
Urinary Metanephrines

Abstract Measurements of urinary metanephrines by the Pisano procedure (Clin. Chim. Acta 5: 406, 1960) are unreliable in patients who are taking propranolol owing to the presence of 4-hydroxypropranolol in the urine. Three properties of this propranolol metabolite lead to interference: (a) it is absorbed and eluted from ion-exchange resins under the conditions Pisano used for metanephrine isolation, (b) at high pH it absorbs at 350 to 360 nm, and (c) it is oxidized by periodate to a substance with negligible absorption in this region. Because 350 to 360 nm is the wavelength used to quantitate vanillin, the product formed from periodate oxidation of metanephrines, and because the unoxidized eluate is used as a specimen blank, the presence of 4-hydroxypropranolol spuriously decreases the measured urinary metanephrines; this has special significance because patients being tested for increased metanephrines are also likely to be receiving propranolol for hypertension.

Embedding Procedure for Water Swollen Samples

1970 ◽  
Vol 28 ◽  
pp. 504-505
Author(s):  
Ann M. Thomas ◽  
Virginia Shemeley
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Exchange ◽  
Structural Changes ◽  
Cross Linking ◽  
Ion Exchange Resins ◽  
Transmission Electron ◽  
First Pass ◽  
Exchange Resins

Those samples which swell rapidly when exposed to water are, at best, difficult to section for transmission electron microscopy. Some materials literally burst out of the embedding block with the first pass by the knife, and even the most rapid cutting cycle produces sections of limited value. Many ion exchange resins swell in water; some undergo irreversible structural changes when dried. We developed our embedding procedure to handle this type of sample, but it should be applicable to many materials that present similar sectioning difficulties.The purpose of our embedding procedure is to build up a cross-linking network throughout the sample, while it is in a water swollen state. Our procedure was suggested to us by the work of Rosenberg, where he mentioned the formation of a tridimensional structure by the polymerization of the GMA biproduct, triglycol dimethacrylate.

Applications of Ion Exchange Resin in Oral Drug Delivery Systems

2017 ◽  
Vol 7 (03) ◽  
Author(s):  
Kathpalia Harsha ◽  
Das Sukanya
Keyword(s):  
Drug Delivery ◽  
Ion Exchange ◽  
Drug Delivery Systems ◽  
Oral Drug Delivery ◽  
Physical Stability ◽  
Delivery Systems ◽  
Oral Drug ◽  
Ion Exchange Resins ◽  
Exchange Resins ◽  
Oral Drug Delivery Systems

Ion Exchange Resins (IER) are insoluble polymers having styrene divinylbenzene copolymer backbone that contain acidic or basic functional groups and have the ability to exchange counter ions with the surrounding aqueous solutions. From the past many years they have been widely used for purification and softening of water and in chromatographic columns, however recently their use in pharmaceutical industry has gained considerable importance. Due to the physical stability and inert nature of the resins, they can be used as a versatile vehicle to design several modified release dosage forms The ionizable drug is complexed with the resin owing to the property of ion exchange. This resin complex dissociatesin vivo to release the drug. Based on the dissociation strength of the drug from the drug resin complex, various release patterns can be achieved. Many formulation glitches can be circumvented using ion exchange resins such as bitter taste and deliquescence. These resins also aid in enhancing disintegrationand stability of formulation. This review focuses on different types of ion exchange resins, their preparation methods, chemistry, properties, incompatibilities and their application in various oral drug delivery systems as well as highlighting their use as therapeutic agents.

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