Isolation of cytotoxic diterpenoids from the Chilean medicinal plant Azorella compacta Phil from the Atacama Desert by high-speed counter-current chromatography.
Azorella compacta (Apiaceae) is a native Chilean cushion shrub which produces a resin containing mulinane and azorellane diterpenoids. This plant has been used since pre-Colombian times to treat inflammation and dental neuralgias. In this work the first preparative fractionation of diterpenoids present in this plant by means of high-speed counter-current chromatography (HSCCC) was applied, and cytotoxic effects of the isolated compounds were evaluated for the first time against a panel of MCF7 cells. The major compounds isolated were identified by means of spectroscopy as azorellanol, 13α, 14α-dihydroxymulin-11-en-20-oic acid, mulinolic acid, mulin-11,13-dien-20-oic acid, 17-acetoxy-mulin-11,13-dien-20 oic acid, and 17-acetoxy-mulinic acid (compounds 7, 9-11 and 13, respectively), and four minor diterpenoids [7-deacetyl-azorellanol (6), 13-epi-azorellanol, 7-acetoxy-mulin-9,12-diene, and 17-acetoxy-mulin-11,13-dien-20-oic acid (compounds 4, 8 and 12)], together with three new minor diterpenoids: 13β,14β-dihydroxymulin-11-en-20-oic acid (1), 13-epiazorellanone (2) and 13-epi-7-deacetyl-azorellanol (3) were identified. Besides, compounds 4, 6, 7, 8 and 11 displayed good cytotoxic activity (less than 50% cell viability at 100 µM). Among them, compound 7, an acetylated azorellane, was the most active. HSCCC allowed the isolation of 13 diterpenoids present in A. compacta. Three compounds are reported for the first time. Isolated azorellanes are more potent cytotoxic agents than are mulinanes. © 2015 Society of Chemical Industry.
- 1Laboratorio de Productos Naturales, Facultad de Ciencias Básicas, Departamento de Química, Universidad de Antofagasta, Av. Coloso S-N, Antofagasta, 1240000, Chile.
- 2Laboratorio de Investigación e Innovación Biomédica (LIIB), Centro de Investigaciones del Hombre en el Desierto (CIHDE), Av. General Velásquez, 1775, Arica, Chile.
- 3Facultad de Ciencias de la Salud, Universidad de Tarapacá, Av. General Velásquez, 1775, Arica, Chile.
- 4Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitz-Strasse 20, D-38106, Braunschweig, Germany.
- 5Departamento de Química, Universidad Católica del Norte, Av. Angamos 610, Antofagasta, 1240000, Chile.
J Sci Food Agric. 2015 Sep 7. doi: 10.1002/jsfa.7451