Crystal structure determination of Jatrorrhizine chloride

Optimum resolution data of powder X-ray diffraction (PXRD) for Jatrorrhizine (Jat) were collected by an X’ Pert Pro MPD diffractometer with an X’celerator detector under the stepwise scanning condition as 8.255 ms and 0.00836° per step, 2θ range of 5°―80° and total scanning period of 8―10 min. Indexing of the crystal system and a search of the space group from the powder X-ray diffraction data were con-ducted by the computational crystallography method. The pilot crystal models of Jat were globally op-timized with Monte Carlo method and then refined with the Rietveld method. In parallel with PXRD test, single crystals of Jat were cultured in an aqueous solution by a slow-decreasing temperature method, then its crystal structure was determined by single crystal X-ray diffraction (SCXRD). Both crystal structures from PXRD and SCXRD are identical. The results show that the crystal structure of Jat be-longs to a monoclinic system and the space group P21/c. The parameters of cell dimensions from PXRD are a =7.69 Å, b = 12.55 Å, c = 20.89 Å, β = 106.53°, Z = 4, and V = 1933.4 Å3, meanwhile the parameters from SCXRD are a = 7.72 Å, b = 12.61 Å, c =20.99 Å, β=106.38°, Z =4, and V =1961.3 Å3.