title: Secondary metabolites from two species of Tolpis and their biological activities.
abstract: Phytochemical research of two Tolpis species, T. proustii and T. lagopoda, led to the isolation of three new compounds: 30-chloro-3&#946;-acetoxy-22&#945;-hydroxyl-20(21)-taraxastene (1), 3&#946;,22&#945;-diacetoxy-30-ethoxy-20(21)-taraxastene (2) and 3&#946;,28-dihydroxy-11&#945;-hydroperoxy-12-ursene (3). The structures of the new compounds were elucidated by means of extensive IR, NMR, and MS data and by comparison of data reported in the literature. The in vitro antioxidant activities of the extracts were assessed by the DPPH and ABTS scavenging methods. The cytotoxicity of several known compounds and its derivatives was also assessed against human myeloid leukemia K-562 and K-562/ADR  cell lines.
authors.affiliation: Departamento de Química, Unidad Asociada al CSIC, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain. jtriana@dqui.ulpgc.es
authors.forename: Jorge
authors.initials: J
authors.lastname: Triana
authors.forename: Mariana
authors.initials: M
authors.lastname: López
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Pérez
authors.forename: Milagros
authors.initials: M
authors.lastname: Rico
authors.forename: Aroa
authors.initials: A
authors.lastname: López
authors.forename: Francisco
authors.initials: F
authors.lastname: Estévez
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Marrero
authors.forename: Ignacio
authors.initials: I
authors.lastname: Brouard
authors.forename: Francisco
authors.initials: F
authors.lastname: León
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D019659:Asteraceae / Q000737:chemistry*; D001713:Biphenyl Compounds / Q000737:chemistry; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D005609:Free Radicals / Q000737:chemistry; D006801:Humans; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D021241:Spectrometry, Mass, Electrospray Ionization; D013055:Spectrophotometry, Infrared; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: C579365:30-chloro-3beta-acetoxy-22alpha-hydroxyl-20(21)-taraxastene; C579364:3beta,22alpha-diacetoxy-30-ethoxy-20(21)-taraxastene; C579362:3beta,28-dihydroxy-11alpha-hydroperoxy-12-ursene; D000972:Antineoplastic Agents, Phytogenic; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D005609:Free Radicals; D010851:Picrates; D010936:Plant Extracts; D014315:Triterpenes; C004931:1,1-diphenyl-2-picrylhydrazyl