Dibenzoylglucoxlose : a natural benzoyl derivate of a new disaccharide / by Frederick Belding Power and Arthur Henry Salway.

  • Power, Frederick B. (Frederick Belding), 1853-1927
Date:
1914.]
Catalogue details

Licence: Public Domain Mark

Credit: Dibenzoylglucoxlose : a natural benzoyl derivate of a new disaccharide / by Frederick Belding Power and Arthur Henry Salway. Source: Wellcome Collection.

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    extremely bitter taste, and as this property is also exhibited, although in a less degree, by penta-acetyldextrose (Ber., 1889, 22, 1466), it is possibly common to the acyl derivatives of the sugars. The substance has no reducing action on Fehling’s solution. It is strongly laevorotatory, its specific rotation having been determined with the following result: 05094,* made up to 20 c.c. with methyl alcohol, gave aD — 5°26/ in a 2-dcm. tube, whence [ot]D —106'7°. Penta-acetyldibenzoylgluco xylose, C11H1oO10(CO*C6Hri)2*(CO,CH3)5. This compound was prepared primarily for the purpose of obtain¬ ing a derivative of dibenzoylglucoxylose which would be suitable for the determination of the molecular weight of the latter by the cryoscopic method. A quantity of dibenzoylglucoxylose was heated for several hours with an excess of acetic anhydride, and the pro¬ duct then poured into water, when the acetyl derivative quickly separated in the solid state. This was collected and purified by crystallisation from absolute acetic acid, from which it was deposited in slender needles, melting at 203°. The substance was anatysed, and its molecular weight determined, with the following results: 0*1002 gave 0-2094 C02 and 0-0473 H20. C = 57‘0; H = 5*2. 02964 in 263 nitrobenzene gave \t — 0-110°. M.W. = 717. 02609 „ 27*4 absolute acetic acid gave — 0048°. M.W. = 778. C35H38017 requires C = 57‘5; H = 52 per cent. M.W. = 730. The number of acetyl groups in this compound cannot be ascer¬ tained from its analysis, but an investigation of the action of alkali hydroxides on it and the original dibenzoyl compound, as described below, indicated that five acetyl groups were present. It is, how¬ ever, evident from the above results that the original compound, dibenzoylglucoxylose, is correctly represented by the formula C25H28012, thus confirming the previous determination of its molecular weight (loc. cit.) by the microscopic method. Penta-acetyldibenzoylglucoxylose is sparingly soluble in alcohol, but more readily so in benzene, chloroform, or acetic acid. It is quite insoluble in water, and possesses only a faintly bitter taste. Alkaline Hydrolysis of Dibenzoylglucoxylose. Formation of Glucoxylose, C'nH20O10, and Benzoic Acid. In order to ascertain the best conditions for the alkaline hydro¬ lysis of the compound, a number of preliminary experiments were first conducted with the use of a known volume of standard alkali under varying conditions, and determining the amount of alkali