title: Casearin X, its degradation product and other clerodane diterpenes from leaves of Casearia sylvestris: evaluation of cytotoxicity against normal and tumor human cells.
abstract: An EtOH extract of the leaves of Casearia sylvestris afforded new clerodane diterpene, casearin X, together with the known compounds casearins B, D, L, and O, and caseargrewiin F. Casearin X degraded to the corresponding dialdehyde when stored in CDCl(3). The diterpenes isolated were cytotoxic to human cancer cell lines, with caseargrewiin F being the most active and the new clerodane, casearin X, the second active compound with IC(50) values comparable to the positive control doxorubicin. All isolated diterpenes showed lower activities against normal human cells than against cancer cell lines, which might indicate a possible selective action on cancer cells. Casearin X dialdehyde was not cytotoxic to cancer cells indicating that the occurrence of these CO groups at C(18) and C(19) is incompatible with the cytotoxic activity.
authors.affiliation: Núcleo de Bioensaios, Biossíntese e Ecofisiologia de Produtos Naturais, Instituto de Química, São Paulo State University, CP 355, 14800-900, Araraquara-SP, Brazil.
authors.forename: André Gonzaga
authors.initials: AG
authors.lastname: dos Santos
authors.forename: Paulo Michel Pinheiro
authors.initials: PM
authors.lastname: Ferreira
authors.forename: Gerardo Magela
authors.initials: GM
authors.lastname: Vieira Júnior
authors.forename: Carla Cristina
authors.initials: CC
authors.lastname: Perez
authors.forename: Aristeu
authors.initials: A
authors.lastname: Gomes Tininis
authors.forename: Geraldo Humberto
authors.initials: GH
authors.lastname: Silva
authors.forename: Vanderlan da Silva
authors.initials: Vda S
authors.lastname: Bolzani
authors.forename: Letícia Veras
authors.initials: LV
authors.lastname: Costa-Lotufo
authors.forename: Cláudia do O
authors.initials: Cdo O
authors.lastname: Pessoa
authors.forename: Alberto José
authors.initials: AJ
authors.lastname: Cavalheiro
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity; D037821:Casearia / Q000737:chemistry*; D045744:Cell Line, Tumor; D045785:Diterpenes, Clerodane / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D018515:Plant Leaves / Q000737:chemistry
chemical_list: C548433:1-(acetyloxy)-3,5,6,6a,7,8,9,10-octahydro-10-hydroxy-7,8-dimethyl-7-(3-methylpenta-2,4-dien-1-yl)naphtho(1,8a-c)furan-3,5-diyl dibutanoate; D000972:Antineoplastic Agents, Phytogenic; D045785:Diterpenes, Clerodane