title: Diterpenoids from Haplopappus rigidus.
abstract: Fractionation of the aerial parts of Haplopappus rigidus Phil., directed by the brine shrimp lethality test (BST), has led to the isolation of two new diterpenoids, rigidusol and deacetylrigidusol. Their structures were established as 13-hydroxy-18-acetoxy-cis-cleroda-3,14-diene (8betaH, 10betaH, 19beta, 20alpha form) and 13,18-dihydroxy-cis-cleroda-3,14-diene (8betaH, 10betaH, 19beta, 20alpha form), respectively. Rigidusol exhibit moderate cytotoxic activity against human breast adenocarcinoma cell line MCF-7. Their structures were established by spectral data, in particular using 2D NMR spectroscopy (DEPT, DQF-COSY, HMQC and HMBC).
authors.affiliation: Departamento de Química, Facultad de Ciencias Básicas, Universidad de Antofagasta, Chile.
authors.forename: G
authors.initials: G
authors.lastname: Morales
authors.forename: P
authors.initials: P
authors.lastname: Sierra
authors.forename: L A
authors.initials: LA
authors.lastname: Loyola
authors.forename: J
authors.initials: J
authors.lastname: Borquez
mesh_terms: D019659:Asteraceae / Q000737:chemistry*; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation
chemical_list: D004224:Diterpenes; C420184:deacetylrigidusol 2; C420183:rigidusol 1