Elucidating the Polymorphism of Xanthone: A Crystallization and Characterization Study.

Area of Science:

• Solid-state chemistry
• Crystallography
• Materials science

Background:

• Xanthones are bioactive oxygenated molecules with antioxidant, anticancer, and anti-inflammatory properties.
• Understanding xanthone polymorphism is crucial for developing new pharmaceutical, nutraceutical, and agrochemical products.
• Previous studies reported two different crystal structures for 9-xanthone, but their distinction was unclear.

Purpose of the Study:

• To resolve the ambiguity surrounding the polymorphism of xanthone.
• To investigate the existence of distinct crystal structures for xanthone.
• To develop a reliable workflow for identifying twinned crystal structures in polymorphic systems.

Main Methods:

• Thermal analysis
• Powder X-ray diffraction (XRD)
• Synchrotron single-crystal XRD
• Optical microscopy
• Principal Component Analysis (PCA) for data analysis

Main Results:

• The study provides a definitive analysis of xanthone polymorphism, resolving previous ambiguities.
• A novel workflow combining high-resolution synchrotron XRD and PCA was established for accurate identification of polymorphic forms and phase transitions.
• Crystallization experiments were optimized to yield different xanthone crystal structures.

Conclusions:

• The research clarifies the crystal structure of xanthone, essential for its bioactive applications.
• The developed workflow offers a robust method for analyzing polymorphism in other crystalline systems.
• Accurate characterization of xanthone solid forms will aid in the design of improved products.