Bioactive guaianolides from siyekucai (Ixeris chinensis).
Zhang S, Zhao M, Bai L, Hasegawa T, Wang J, Wang L, Xue H, Deng Q, Xing F, Bai Y, Sakai J, Bai J, Koyanagi R, Tsukumo Y, Kataoka T, Nagai K, Hirose K, Ando M.
Two new guaianolides, named chinensiolides D (5) and E (6), were isolated from Ixeris chinensis Nakai, and their structures were determined to be 10alpha-hydroxy-3-oxoguaia-11(13)-eno-12,6alpha-lactone (5) and 10alpha-hydroxy-3beta-O-[2,6-di(p-hydroxyphenylacetyl)-beta-glucopylanosyl]guaia-4(15),11(13)-dieno-12,6alpha-lactone (6). The first isolation of (11S)-10alpha-hydroxy-3-oxoguaia-4-eno-12,6alpha-lactone (4) from natural sources and its characterization are also reported. Chinenciolide E (6) showed significant growth inhibitory activity toward VA-13 malignant lung tumor cells (IC50 = 0.72 microM).