Refinement of the Crystal Structure of Aconitine

The crystal of aconitine has been obtained through an unexpected spontaneous change of the solid power of aconitine in air and characterized by single-crystal X-ray diffraction analysis and elemental analysis. Crystallographic data: orthorhombic, space group P212121 with a = 17.0745（6）, b = 15.5990（6）, c = 12.2443（6） ?, V = 3261.2（2） ?3, Z = 4, C34H47NO11, Mr = 645.73, Dc = 1.315 g/cm3, F（000） = 1384, μ（MoKa） = 0.098 mm-1, R = 0.0605 and wR = 0.1311. Aconitine is diester diterpenoid alkaloid, and its main structure is composed of four six-membered and two five-membered rings. The intramolecular and intermolecular O–H···O and C–H···O hydrogen bonds extend the adjacent molecules into a one-dimensional chain and a two-dimensional framework, which may be the essential reason for the change.