Elucidating the Structure and Identity of Pinckneyin, a Historical Natural Product from Pinckneya bracteata

High Resolution Image Download MS PowerPoint Slide Pinckneya bracteata (Georgia bark) was historically used in the southeastern United States to treat intermittent fevers and has long been believed to contain quinine. In 1885, a bitter crystalline substance termed pinckneyin was isolated, but its structure remained unknown. Reproduction of the original extraction procedure combined with modern spectroscopic and single-crystal X-ray diffraction analysis definitively identifies pinckneyin as 7-hydroxycoumarin (umbelliferone). This work resolves a long-standing ambiguity in the phytochemical literature and clarifies the chemical basis for reassessing the historical medicinal use of P. bracteata .