title: Maoecrystal Z, a cytotoxic diterpene from Isodon eriocalyx with a unique skeleton.
abstract: [structure: see text] A novel diterpene with an unprecedented tetracyclic 6,7:8,15-di-seco-7,20-olide-6,8-cyclo-ent-kaurane skeleton, named maoecrystal Z (1), has been isolated from the leaves of a Chinese medicinal herb, Isodon eriocalyx (Labiatae). Its structure was determined by comprehensive NMR and MS spectroscopic analysis coupled with single-crystal X-ray crystallographic diffraction. Compound 1 exhibited comparable inhibitory effect against human K562 leukemia, MCF7 breast, and A2780 ovarian tumor cells with IC(50) = 2.90, 1.63, and 1.45 microg/mL and with camptothecin and paclitaxel as the positive controls.
authors.affiliation: Chinese Medicine Laboratory, Hong Kong Jockey Club Institute of Chinese Medicine, Hong Kong, P. R. China.
authors.forename: Quan-Bin
authors.initials: QB
authors.lastname: Han
authors.forename: Susan
authors.initials: S
authors.lastname: Cheung
authors.forename: Joseph
authors.initials: J
authors.lastname: Tai
authors.forename: Chun-Feng
authors.initials: CF
authors.lastname: Qiao
authors.forename: Jing-Zheng
authors.initials: JZ
authors.lastname: Song
authors.forename: Ting-Fai
authors.initials: TF
authors.lastname: Tso
authors.forename: Han-Dong
authors.initials: HD
authors.lastname: Sun
authors.forename: Hong-Xi
authors.initials: HX
authors.lastname: Xu
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D018360:Crystallography, X-Ray; D045786:Diterpenes, Kaurane / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D005260:Female; D006801:Humans; D037602:Isodon / Q000737:chemistry*; D015394:Molecular Structure; D010946:Plants, Medicinal / Q000737:chemistry*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D045786:Diterpenes, Kaurane; C520391:maoecrystal Z