New 7,20:14,20-Diepoxy ent-Kauranoids from Isodon xerophilus
journal contributionposted on 12.04.2000, 00:00 by Ai-Jun Hou, Ma-Lin Li, Bei Jiang, Zhong-Wen Lin, Shu-Yu Ji, Yi-Ping Zhou, Han-Dong Sun
Three new 7,20:14,20-diepoxy-ent-kaurane diterpenoids, xerophilusins A−C (1−3), together with a known one, macrocalin B (4), were isolated from the leaves of Isodon xerophilus. Their structures were elucidated on the basis of their spectral properties and X-ray crystallographic analysis. Compounds 1, 2, and 4 showed significant cytotoxic activity against K562, HL-60, and MKN-28 cells.