Investigation on the roots of Helianthella quinquenervis (Hook.) A. Gray (Asteraceae), led to the isolation of one new benzofuran (6-methoxy-tremetone (1)) and a new prenylacetophenone (4-beta-D-(glucopyranosyloxy)-3-[3-methoxy-trans-isopenten-1 -yl] acetophenone (3)). In addition,