Three new chromanones from Calea clausseniana.

Abstract

Three new chromanones, uniflorol A acetate (1), uniflorol B acetate (2), and 2,2-dimethyl-6-{1-[(4’- acetoxy)angeloyloxy]ethyl}chroman-4-one (3), together with the known chromanone 4, and two known p-hydroxyacetophenone derivatives, 5 and 6, were isolated from the CH2Cl2 crude extract of the underground parts of Calea clausseniana Baker. The structures of the new compounds were elucidated by spectroscopic analyses, including 2D-NMR techniques.