Studies; Reprints Volume 21

Studies; Reprints Volume 21

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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1915 edition. Excerpt: ...with The hydrochlorides differ in their crystal form, in their solubility in water and in dilute alcohol, in their melting points, and their specific rotations. The salt of glucosamine is quite soluble in water, almost insoluble in 80 per cent alcohol; the salt of the new substance is quite soluble in 80 per cent alcohol. The salt of glucosamine showed no tendency to melt at a temperature considerably above 2o0C., whereas the melting point of the hydrochloride of chondrosamine is sharp at 182C. The optical rotation of the two substances is particularly worthy of note. That of the salt of chondrosamine has an initial specific rotation of 129, is mutarotating and reaches the equilibrium at 93; glucosamine hydrochloride also is mutarotating, with the initial rotation of 100 and the equilibrium point at 73. bromine. Received for publication, May 5, 1914. 1This Journal, xv, p. 69 and p. 155, 1913. If the rotation of chondrosamine is measured at room temperature and in 1 per cent solution it may show the effect of mutarotation already at the time of the first reading. This occurred in our first experiments with the substance, and the occurrence misled us into the belief that chondrosamine possessed the specific rotation of glucosamine. In order to avoid this possible error the first reading should be taken immediately after solution of the substance is effected and precautions should be exercised to prevent the temperature of the solution from rising above 0C. The osazones differ in their melting points, and in their specific rotation. The phenylosazone of glucosamine is regarded as identical with glucosazone. A sample prepared by us had a melting point of 208C, possessed the solubility of glucosazone and hence could be recrystallized out of 98...show more

Product details

  • Paperback
  • 189 x 246 x 12mm | 395g
  • Rarebooksclub.com
  • United States
  • English
  • black & white illustrations
  • 1236992792
  • 9781236992796