The constituents of senna leaves / by Frank Tutin.

Tutin, Frank.

Date:: [1913?]

Credit: The constituents of senna leaves / by Frank Tutin. Source: Wellcome Collection.

14/22 page 2017

$petroleum liquid was then evaporated, and the residue dissolved in methyl alcohol, and esterified by means of sulphuric acid. On cooling the mixture a quantity of a dark green, wax-like solid separated, which was collected. This solid, on examination, was found to consist of chlorophyll, together with myricyl alcohol, which had escaped extraction during the removal of the unsaponi- fiable material. The methyl-alcoholic filtrate was poured into water, and the mixture extracted with ether, the resulting ethereal solu¬ tion being deprived of some unesterified acid and much chlorophyll by extracting it with aqueous potassium hydroxide, and subse¬ quently washing it with water. The ethereal liquid was then evaporated, and the residue purified by distillation under dimin¬ ished pressure, when a quantity (about 15 grams) of a pale brown liquid was obtained. This portion of methyl ester, together with that previously obtained from the free fatty acids, was then frac¬ tionally distilled five times under diminished pressure, when the following fractions were obtained: Below 240°; 240—250°; 250—260°; above 260°/60 mm. The fraction boiling below 240° represented about one-third of the total material, and consisted of methyl palmitate (m. p. 29°). On hydrolysis it yielded palmitic acid, which formed colourless plates melting at 62*5°. (Found, C=74*8; H = 12*5. Calc., C=75*0; H = 12*5 per cent.) The fraction boiling at 240—250°/60 mm. was somewhat larger than the preceding one. On hydrolysis it yielded a mixture, which contained a small proportion of unsaturated acid, but consisted for the most part of palmitic acid, together with apparently a little stearic acid. The portion of the material distilling at 250—260°/60 mm., when hydrolysed, gave a small amount of unsaturated acid, together with a solid acid. The latter, when crystallised five times alter¬ nately from alcohol and ethyl acetate, yielded stearic acid melting at 69°. (Found, 0 = 75*9; H = 12*7. Calc., C=76'l; H = 12*7 per cent.) % The fraction of ester boiling above 260°/60 mm. wras too small for examination. Examination of the TJ nsaponifable Material. The combined ethereal extracts containing the unsaponifiable material, which had been obtained as above described, were washed, dried, and evaporated. The residue was then heated with a large amount of alcohol, and the mixture filtered whilst hot, thereby removing a quantity of almost black, tarry material. The filtrate, which was dark brown, deposited, on cooling, a quantity of an$

The constituents of senna leaves / by Frank Tutin.

Licence and re-use

Contents