The alkaloids of ergot. [Pt. I] / by George Barger and Francis Howard Carr.

  • George Barger
Date:
1907
Catalogue details

Licence: In copyright

Credit: The alkaloids of ergot. [Pt. I] / by George Barger and Francis Howard Carr. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    II. By a microscopic method, due to one of us (Trans., 1905, 87, 1756), 0*0858 in 1*06 pyridine at 80° = 0*17- 0*18 mole.; M.W. = 463. The number of carbon, oxygen, and nitrogen atoms in ergotinine seems now to be established with tolerable certainty. The number of hydrogen atoms is less certain ; it must, however, be an odd number, in order to make the total number of valencies even, and can therefore not be forty, as Tanret suggests. From our analyses we conclude that there are very probably 39, possibly 41 hydrogen atoms in ergotinine. The formula C35H3905N5 requires 6*45 per cent., the formula C35H4i05N5 6*76 per cent., of hydrogen : on the average we found 6*52 per cent, in good agreement with the first formula, since the amount of water found in combustions is generally somewhat too high. Properties of Ergotinine. Ergotinine crystals consist of long needles, the sides of which are not quite parallel; the ends are symmetrically replaced by a pair of faces, and the extinction is straight.* When placed in a bath at 210° and heated further ergotinine sinters, darkens and melts at temperatures up to 229° (corr.). Kraft gives m. p. 219°, Tanret 205°. We have also frequently found 219—220° (uncorr.). The decomposition point is not very characteristic and depends greatly on the rate of heating. Solubility determinations were made by shaking the powdered alkaloid in the cold with the solvent, and by rapidly filtering the boiling solution. One part of ergotinine dissolves at 10° in 312 parts by weight of absolute ethyl alcohol, at 18° in 292 parts of alcohol, in 1,020 parts of absolute ether, in 91 parts of ethyl acetate, and in 26 parts of acetone; further, in 77 parts of boiling benzene, 52 parts of boiling ethyl alcohol, and 56 parts of boiling methyl alcohol. It is extremely soluble in cold chloroform, moderately so in amyl alcohol, methylal or xylene, and insoluble in light petroleum. The determination of the specific rotation at 10° in a saturated solu- tion in ethyl alcohol, prepared by shaking in the cold, gave aD + 1 *91°; 1= 0*22 dcm. ; c = 0*257 ; [a]D +338°. Tanret found + 334° and + 336°. Five different specimens of ergo- tinine, in alcoholic solutions prepared by boiling, with c = 0*172 —0*257, gave at 10—18° [a]D +320°, +328°, +326°, +330°, + 327°; mean +328°. The rotatory power of an alcoholic solution of ergotinine falls * For this description of ergotinine crystals and for 'others of the crystals of ergotoxine salts given later, we are indebted to Prof. W. J. Pope and tender him our best thanks for his assistance in this respect.
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