Notes on the alkaloid indaconitine

Properties:—Indaconitine is soluble in acetone, chloroform, alcohol, or ether, but practically insoluble in light petroleum or water.

By the addition of light petroleum to a solution of the base in alcohol, chloroform, or ether, well defined crystals may be readily obtained.

A peculiar property of indaconitine which sharply distinguishes it from aconitine is its capability of crystallising in several forms from the same solvent. The crystalline form appears to depend on the purity of the substance and on the strength of the solution. By rapid crystallisation, the base is deposited from ether in rosettes of needles, but if allowed to crystallise slowly, or if the substance is not quite pure, it is obtained as transparent, hexagonal prisms or large, irregular masses. If a somewhat concentrated solution is decanted from a flask, the indaconitine crystallises on the sides, either in a characteristic fern-like form or in thin, circular layers of silky needles.

Indaconitine crystallises uncombined with its solvent.

The melting point of indaconitine, if immersed in the bath at 150° and the temperature slowly raised, is 202-203°. Crystallographically, indaconitine very closely resembles aconitine, and on further investigation may prove to be isomorphous.

Composition:—C_34: H₄₇ O₁₀ N, requires C=64'86; H=7'47, and N—2'22 per cent.

Physiological action:—This differs in degree only, and not in kind, from that of aconitine and pseudo-aconitine. As in the case of other “aconitines,” the toxic action of indaconitine is virtually abolished by the removal of the acetyl group, which occurs in the formation of indbenzaconine, an alkaloid which is scarcely poisonous.