The solid phase of ginkgolide K: Structure and physicochemical properties

• Four solvates of ginkgolide K (forms I–IV) and one solvate-free (V) have been reported for the first time.
• X-ray diffraction, thermal analysis and IR spectra were used to characterize the solid phases of ginkgolide K.
• The crystal structure of forms I–IV were analyzed and discussed in detail.

Four solvates of ginkgolide K with dimethyl sulfoxide(I), water molecule(II), acetone-isopropyl alcohol(III), methanol-ethanol(IV) and one solvate-free (V) have been described in this work. And the solid-state techniques such as X-ray diffraction, thermal analysis and Fourier transform infrared spectroscopy were used for characterization of the solid phases. The single crystal structures of ginkgolide K solvates (I–IV) have been determined. Ginkgolide K shows strong inflexibility and solvents being incorporated in the crystal structure results in it forming polymorphs via the diverse hydrogen bond interactions.