Isolation of the pressor principles of putrid meat / by George Barger and G.S. Walpole.

  • George Barger
Date:
[1909?]
Catalogue details

Licence: Public Domain Mark

Credit: Isolation of the pressor principles of putrid meat / by George Barger and G.S. Walpole. Source: Wellcome Collection.

    5/16 page 345
    Identification of the base soluble in chloroform. The acid solution of the bases was washed with chloroform made alkaline and repeatedly extracted with ether. The ethereal solution was dried with sodium sulphate and precipitated with an ethereal solution of anhydrous oxalic acid. The filtrate from the precipitated oxalates did not contain any pressor substances ; the oxalate itself readily crystallised from alcohol and the crystalline oxalate represented nearly the whole of the chloroform-soluble pressor principle; from the mother liquors on concentration a little of a more soluble oxalate eventually separated, but this had no pressor action. After recrystallisation from a mixture of alcohol and acetone the physiologically active oxalate melted at 166 and was analysed. The substance was dried in vacuo over sulphuric acid ; it was found impossible to dry to constant weight at 100 because of decomposition and loss of base. 0-2080 grm. gave 0-3618 C02 and 0-1573 H20 ; C = 47-53, H = 8-40. 0-2046 grm. gave 13-7 c.c. of moist N at 765 mm., and 11° C. = 8-0 per cent. N. Found Calculated for c7h15o4n c 47-53 47-46 H 8-40 8-48 N 8-0 7-9 The analyses agree with the formula C5H13N. C2H204 which is that of the acid oxalate of an amylamine. By heating the salt with an excess of lime we obtained a small quantity of the free base which boiled at 89—90° and possessed the characteristic smell of a fatty amine. (Isoamylamine is stated to boil at 95°.) We determined its vapour density according to Victor Meyer’s method. 0*0745 gave 21 c.c. of moist air at 761 mm. and 10° C. Y.D. = 41-5; vapour density calculated for C5H13N = 43-5. The free amine was converted into the hydrobromide by adding alcoholic hydrobromic acid to its solution in ether. It formed glistening plates m.p. 225° which were non-deliquescent but extremely soluble in water. The hydrochloride, i.e. the salt first obtained by Abelous and his colleagues, was even more soluble and could not be obtained pure. 0-1293 grm. gave 0-1712 C02 and 0-0939 H20; C = 36*l, H = 81. Calculated for C5H1SN, HBr. 35-7 8-3 C H Found 36-1 8-1
    digitised image 1
    digitised image 2
    digitised image 3