Activity-directed fractionation of a CH(2)Cl(2)-MeOH (1:1) extract of Leucophyllum ambiguum led to the isolation of two new lignans designated with the trivial names of 2'-methoxykobusin (1) and 2'-methoxy-4' '-hydroxydemethoxykobusin (2). In addition, the known compounds kobusin (3), 2',2'