The alkaloids of Alstonia barks. Pt. 2, A. macrophylla, Wall; A. somersetensis, F.M. Bailey; A. verticillosa, F. Muell; A. villosa, Blum / by T.M. Sharp.

  • Sharp, Thomas Marvel.
Date:
[1934]
Catalogue details

Licence: Public Domain Mark

Credit: The alkaloids of Alstonia barks. Pt. 2, A. macrophylla, Wall; A. somersetensis, F.M. Bailey; A. verticillosa, F. Muell; A. villosa, Blum / by T.M. Sharp. Source: Wellcome Collection.

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    The colour reactions of the above alkaloids are given in the following table. Alkaloid. Villalstonine Vanillin-alcoholic HC1. Immediate pink colour, gradually becomes blue-violet Gaebel’s reagent. Reddish- brown Glyoxylic reagent. Not char¬ acteristic Cone. hno3. Greenish- yellow Cone. H2S04. Brown, changing through purple to blue Macralstonine Pale yellow, changes to orange and finally to brownish-pink Brown Not char¬ acteristic Yellow Yellowish-green, be¬ coming yellow Macralston- idine No colour for some hours, gradually be¬ comes pink Red Not char¬ acteristic Yellow No colour at first; becomes blue then pink Base V No colour for some hours, pink after 24 hours Yellow Pink ring Red No colour Sulphate of No immediate colour, Reddish- Not char- Yellow Yellowish-brown, base M amethyst after some hours brown acteristic changing to yellow The echitamine hydrochloride from A. verticillosa was recrystallised from water until the m. p. and specific rotation remained constant. It then had m. p. 293—295° (decomp.), alone or admixed with an authentic specimen of echitamine hydrochloride; [a]D — 58*8° (c — 1-003 in water) (recorded [a]D — 54-3°). It gave a pure blue colour with Hopkins and Cole’s glyoxylic reagent, a magenta colour with vanillin-hydrochloric acid, and a bright red coloration with strong nitric acid (Found, on dry salt : C, 62-9, 63-0; H, 7-0, 7-0; N, 6-6, 6-6; Cl, 8-7, 8-5. Calc, for C22H2804N2,HC1 : C, 62-8; H, 6-95; N, 6-7; Cl, 8-4%). The author thanks Dr. T. A. Henry for placing these barks at his disposal and for his interest and advice during the work, Messrs. W. A. Cowdrey and A. G. Turner for help with the extraction of the alkaloids, Messrs. A. Bennett and H. C. Clarke for the micro-analyses, and Dr. H. A. D. Jowett for the arrangements for the extraction of A. macrophylla bark. The Wellcome Chemical Research Laboratories, London, N.W. 1. [Received, July 9th, 1934.] Printed in Great Britain by Richard Clay & Sons, Limited, Bungay, Suffolk.
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