A diaacetylenic spiroketal enol ether epoxide, AL-1, from Artemisia lactiflora inhibits 12-O-tetradecanoylphorbol-13-acetate-induced tumor promotion possibly by suppression of oxidative stress. - Nakamura,Y.; Kawamoto,N.; Ohto,Y.; Torikai,K.; Murakami,A.; Ohigashi,H. (Cancer Lett, 1999)