The Constituents of Iris florentina L. (3). Structure of Irisxanthone, a New C-Glycosylxanthone

Abstract

Irisxanthone (IV), C₂₀H₂₀O₁₁·H₂O, decomposing over 208° without melting, a new C-glycosylxanthone, has been isolated from the rhizoma of Iris florentina L. (Iridaceae) along with mangiferin. The structure of irisxanthone (IV) has been determined as 2-C-β-D-glucopyranosyl-5-methoxy-1, 3, 6-trihydroxyxanthone by chemical and spectral studies.