A Validated HPTLC Densitometric Method for Simultaneous Determination of Evernic and Usnic Acids in Four Usnea Species and Comparison of Their Antioxidant Potential.

A simple, sensitive and precise high-performance thin-layer chromatography method with densitometric detection was used for simultaneous determination of evernic (EV) and (+)-usnic acids (USN) in Usnea aciculifera (UA), U. ghattensis (UG), U. longissima (UL) and U.