title: Three new sesquiterpene lactone dimers from Carpesium macrocephalum.
abstract: Three new sesquiterpene lactone dimers (SLDs), carpedilactones E-G (1-3), together with two known monomeric units, ivalin (4) and alantolactone (5), were isolated from the acetonic extract of Carpesium macrocephalum. Their chemical structures were elucidated by IR, UV, HR-ESI-MS, NMR 1D and 2D experiments, and the absolute configuration of 1-3 was resolved according to the (1)H NMR and CD spectrographic features of 1,3-/2,4-linked SLDs. Furthermore, 1 was unambiguously confirmed by Cu-Kα X-ray crystallographic analysis. Additionally, compounds 1 and 2 were revealed with potent cytotoxicities against human colon cancer HCT116 cells with IC50 values of 2.27 and 3.30 μM, respectively.
authors.affiliation: School of Pharmacy, Second Military Medical University, Shanghai 200433, PR China.
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Zhang
authors.affiliation: School of Pharmacy, Second Military Medical University, Shanghai 200433, PR China.
authors.forename: Xi-Ke
authors.initials: XK
authors.lastname: Xu
authors.affiliation: School of Pharmacy, Second Military Medical University, Shanghai 200433, PR China.
authors.forename: Ji
authors.initials: J
authors.lastname: Ye
authors.affiliation: School of Pharmacy, Second Military Medical University, Shanghai 200433, PR China.
authors.forename: Yong-Xun
authors.initials: YX
authors.lastname: Yang
authors.affiliation: School of Pharmacy, Second Military Medical University, Shanghai 200433, PR China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Gao
authors.affiliation: School of Pharmacy, Second Military Medical University, Shanghai 200433, PR China. Electronic address: faranli@hotmail.com.
authors.forename: Hui-Liang
authors.initials: HL
authors.lastname: Li
authors.affiliation: School of Pharmacy, Second Military Medical University, Shanghai 200433, PR China; Shanghai Institute of Pharmaceutical Industry, Shanghai 200400, PR China. Electronic address: wdzhangy@hotmail.com.
authors.forename: Wei-Dong
authors.initials: WD
authors.lastname: Zhang
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry* / Q000302:isolation & purification; D019659:Asteraceae / Q000737:chemistry*; D045744:Cell Line, Tumor; D006801:Humans; D007783:Lactones / Q000737:chemistry* / Q000302:isolation & purification; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry; D012717:Sesquiterpenes / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D007783:Lactones; D010936:Plant Extracts; D012717:Sesquiterpenes
keywords: Carpedilactones E–G; Carpesium macrocephalum; Cytotoxicity; Sesquiterpene lactone dimers