The nature and origin of the poison of Lotus Arabicus / by Wyndham R. Dunstan and T.A. Henry.

  • Dunstan, Wyndham R. (Wyndham Rowland), 1861-1949.
Date:
1901
Catalogue details

Licence: In copyright

Credit: The nature and origin of the poison of Lotus Arabicus / by Wyndham R. Dunstan and T.A. Henry. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    •1532 gramme of lotusin, hydrolysed by dilute hydrochloric acid, gave dextrose sufficient to produce an amount of cuprous oxide corresponding to ‘1792 gramme CuO = 53'4 per cent, dextrose. The equation C28H31016N + 2H20 = 2C6HMOfl + C15H10O6 + HCN requires the formation of 56‘5 per cent, dextrose. Examination of the Yellow Crystalline product of Hydrolysis, Lotofavin. It was found most convenient in preparing quantities of this material to bring About the hydrolysis by the addition of a little strong hydrochloric acid, warming gently for a few minutes, and rapidly filtering. At first there is some resinous matter produced which remains on the filter. The filtrate deposits almost imme- diately a yellow precipitate which, on examination with a lens, is found to consist of minute needles. The hydrolysis of lotusin is easily effected, even in dilute solution, by hydrochloric acid, but is not readily induced by sulphuric or nitric acids even when the acid solution is warmed for several hours on the water-bath. The insoluble hydrolytic product can he re-crystallised from its solution in hot glacial acetic acid, when it forms bright yellow needles melting indefinitely above 200° C. As the substance is a yellow colouring matter, the name lotof avin is proposed for it. Lotoflavin dissolves in alcohol and in aqueous alkaline solutions with a bright yellow colour, but it is insoluble in water, chloroform, ether, and light petroleum. Its solutions in alcohol form orange-red precipitates with soluble lead and barium salts. Combustions of lotoflavin, re-crystallised several times from acetic acid and dried at 100° C., gave the following results :— T76 gramme gave C02 '4041 gramme = <>2*6 per cent. C. HoO -0581 „ = 379 „ H. •0894 „ C02 '2067 „ = 63D9 „ C. H20 -0232 „ := 2-8 „ H. C16H10O0 requires C 62‘9 per cent. ; H 3‘5 per cent. The amount of lotoflavin produced by the hydrolysis of lotusin was determined by hydrolysing a known weight of the latter with hydrochloric acid, collecting, washing, and weighing the lotoflavin precipitated. ’6128 gramme gave '286 gramme lotoflavin, i.e., 46'6 per cent. C28H31016N = 2C6H1206 requires 44’9 per cent.