Methylation of Guar Polysaccharide

Swanson, John W.

doi:10.1021/ja01172a523

Cited by 12 publications

(6 citation statements)

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“…Horowitz, Bonner and Houlahan have shown, by a study of mutants induced by ultraviolet irradiation, that the mold Neurospora crassa synthesizes choline by an enzymatic stepwise methylation of ethanolamine. 4 It is known that the animal can perform this same (2) Winterstein, Z. physiol.…”

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confidence: 99%

The Biogenesis of Alkaloids. I. The Isolation of N-Methyltyramine from Barley¹

Kirkwood¹,

Marion²

1950

J. Am. Chem. Soc.

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None is new.Cyanic acid was generated by subliming cyanuric acid from a 25-cc. flask connected by a glass joint to a Pyrex tube heated to dull redness in an electric combustion furnace.The exit end of the tube was bent downward to lead the effluent gases into a 50-cc. flask containing the alcohol. A gentle current of carbon dioxide was used to prevent accidental sucking back.In a typical run, 5 g. of cyanuric acid was placed in the generator and 10-15 cc. of the alcohol in the receiver which was clamped in a pan of cold water. When less than 5 cc.of alcohol was available, 10 cc. of dry ether was used as solvent. The cyanuric acid was heated with a free flame, and the carbon dioxide was adjusted so that one bubble per second appeared. Sublimation of the bulk of the cyanuric acid required about fifteen minutes. The receiver was removed, stoppered and left to itself for twentyfour hours.7 When the reaction was at an end as evidenced (6) Microanalyses by E. F. Sb el berg and staff. Melting points are uncorrected.(7) It should be emphasized that the reaction of cyanuric acid with alcohols is not always rapid. ß-Phenylethanol, for example, required several days; simple alcohols, however, usually react so rapidly that the mixture becomes hot.

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confidence: 99%

The Biogenesis of Alkaloids. I. The Isolation of N-Methyltyramine from Barley¹

Kirkwood¹,

Marion²

1950

J. Am. Chem. Soc.

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“…The side Experimental chains are linked at C-6 and are composed of Unless otherwise stated all evaporations were carried galactose and mannose (' 3 13) the former out at 40-50" under reduced pressure. All specific rota- (2)(3)(4)(5)(6)(7)14). It will be seen that the Cassia abfus tions are equilibrium values and melting points are ungalactomannan is essentially similar to other corrected.…”

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confidence: 67%

“…Many such seeds e.g. guar (2,3), fenugreek ( 4 , carob (5,6), lucerne and clover (7), and Kentucky coffee bean (8) have been studied and the structure of galactomannan worked out. It would be interesting to study other seeds of this family and find out the relationship between their polysaccharide material.…”

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confidence: 99%

Galactomannan from Cassiaabsus seed. I. Nature of sugars present, methylation, and periodate oxidation studies

Kapoor¹,

Mukherjee²

1969

Can. J. Chem.

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A galactomannan composed of D-galactose (1 mole) and D-mannose (3 moles) was isolated from the seed of Cassia absus. Methylation and hydrolysis of the galactomannan produced 2,3,4,6-tetra-0-methyl-D-galactose (2 moles), 2,3,6-tri-0-methyl-D-mannose (4.2 moles), 2,3-di-0-methyl-D-mannose (1 mole), and 4,6-di-0-methyl-D-mannose (1 mole). Periodate consumption was 1.09 moles for each hexose unit with concomitant liberation of 0.26 mole of formic acid. The periodate oxidized and the reduced galactomannan afforded, on hydrolysis, glycerol (1.94 moles), erythritol (5 moles), and Dmannose (1.08 moles).On the basis of the above findings, a structure for the galactomannan can be proposed in which mannose units form the main chain and the galactose units are present as branches, the former being attached mostly through 1 + 4 (ca. 85 %) and the rest which is nearly half the branch points through I + 3 or 1 + 2, and branches of single galactose units are attached through 1 -> 6 (ca. 50 %) and therest through 1 -+ 2 o r 1 + 3 .

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“…The Chemical structure of this polysaccharide has been the subject of many studies [2][3][4]. The currently accepted model consists of a straight chain of d-mannose units, linked together by ␤(1 → 4) glycoside linkage s and have on every alternate mannose a single d-glactose unit, joined by ␣(1 → 6) glycoside linkage (Fig.…”

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confidence: 99%