xanthene

Xanthene is a white, crystalline heterocyclic compound with the chemical formula C₁₃H₁₀O. It also refers to an isomer that serves as the parent structure for colored xanthene dyes. These dyes are known for their brilliant, fluorescent colors, ranging from yellow to pink and bluish-red.12

A significant development in xanthene chemistry was the discovery of fluorescein in 1871 by Adolph von Baeyer. While fluorescein itself isn't a practical dye, it's valuable as a marker for sea accidents and a tracer for underground water flow. Derivatives of xanthene, such as eosin, are used in inks, cosmetics, and as food dyes.3