title: New thymol derivatives and cytotoxic constituents from the root of Eupatorium cannabinum ssp. asiaticum.
abstract: Two new thymol (=5-methyl-2-(1-methylethyl)phenol) derivatives, 8,10-didehydro-9-(3-methylbutanoyl)thymol 3-O-tiglate (1) and 9-O-angeloyl-8-methoxythymol 3-O-isobutyrate (2), were isolated from the root of Eupatorium cannabinum ssp. asiaticum, together with six known compounds, 3-8. The structures of 1 and 2 were determined through extensive 1D/2D-NMR and MS analyses. Among the isolates, 9-acetoxy-8,10-epoxythymol 3-O-tiglate (3) was the most cytotoxic, with IC50 values of 0.02±0.01, 1.02±0.07, and 1.36±0.12 μg/ml, respectively, against DLD-1, CCRF-CEM, and HL-60 cell lines. In addition, 10-acetoxy-9-O-angeloyl-8-hydroxythymol (4) and eupatobenzofuran (6) exhibited cytotoxicities, with IC50 values of 1.14±0.16 and 2.63±0.22, and 7.63±0.94 and 2.31±0.14 μg/ml, respectively, against DLD-1 and CCRF-CEM cell lines.
authors.affiliation: Department of Pharmacy of Zuoying Branch of Kaohsiung Armed Forces General Hospital, Kaohsiung 813, Taiwan.
authors.forename: Li-Chai
authors.initials: LC
authors.lastname: Chen
authors.forename: Tzong-Huei
authors.initials: TH
authors.lastname: Lee
authors.forename: Ping-Jyun
authors.initials: PJ
authors.lastname: Sung
authors.forename: Chih-Wen
authors.initials: CW
authors.lastname: Shu
authors.forename: Yun-Ping
authors.initials: YP
authors.lastname: Lim
authors.forename: Ming-Jen
authors.initials: MJ
authors.lastname: Cheng
authors.forename: Wen-Lung
authors.initials: WL
authors.lastname: Kuo
authors.forename: Jih-Jung
authors.initials: JJ
authors.lastname: Chen
mesh_terms: D002460:Cell Line; D004354:Drug Screening Assays, Antitumor; D036602:Eupatorium / Q000737:chemistry*; D006801:Humans; D020128:Inhibitory Concentration 50; D009682:Magnetic Resonance Spectroscopy; D018517:Plant Roots / Q000737:chemistry*; D013943:Thymol / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D013943:Thymol
keywords: Cytotoxic activity; Eupatorium cannabinum; Thymol derivatives