The Department of Botany, The University of Texas at Austin, Austin, TX 78712, U.S.A.
Abstract:
Three new heliangolides (niveusin-A, -B and -C) and three known diterpene carboxylic acids were isolated and characterized from a CHCl3, extract of Helianthus niveus. The structures of the three new lactones were deduced by 1H and 13C NMR as well as extensive decoupling experiments and derivatizations.