title: New Pesticidal Diterpenoids from Vellozia gigantea (Velloziaceae), an Endemic Neotropical Plant Living in the Endangered Brazilian Biome Rupestrian Grasslands.
abstract: Vellozia giganteais a rare, ancient, and endemic neotropical plant present in the Brazilian Rupestrian grasslands. The dichloromethane extract ofV. giganteaadventitious roots was phytotoxic againstLactuca sativa,Agrostis stolonifera, andLemna paucicostata, and showed larvicidal activity againstAedes aegypti. Phytotoxicity bioassay-directed fractionation of the extract revealed one new isopimaradiene, 8(9),15-isopimaradien-1,3,7,11-tetraone, and three new cleistanthane diterpenoids, 7-oxo-8,11,13-cleistanthatrien-3-ol, 3,20-epoxy-7-oxo-8,11,13-cleistanthatrien-3-ol, and 20-nor-3,7-dioxo-1,8,11,13-cleistanthatetraen-10-ol. These new structures are proposed based on interpretation of ¹H,13C, COSY, NOESY, HSQC, and HMBC NMR data. 8(9),15-isopimaradien-1,3,7,11-tetraone was especially phytotoxic with an IC50value (30 μM) comparable to those of commercial herbicides clomazone, EPTC, and naptalam. In addition, 7-oxo-8,11,13-cleistanthatrien-3-ol provided 100% mortality at a concentration of 125 ppm against one-day-oldAe. aegyptilarvae. Our results show that ancient and unique plants, like the endangered narrowly endemic neotropical speciesV. giganteapresent in the Rupestrian grasslands, should also be protected because they can be sources of new bioactive compounds.
authors.affiliation: Department of Microbiology, Federal University of Minas Gerais, Belo Horizonte, MG 31270-901, Brazil. marianacostaferreira@yahoo.com.br.
authors.forename: Mariana C
authors.initials: MC
authors.lastname: Ferreira
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Natural Products Utilization Research University, MS 38677, USA. clcantr1@olemiss.edu.
authors.forename: Charles L
authors.initials: CL
authors.lastname: Cantrell
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Natural Products Utilization Research University, MS 38677, USA. sduke@olemiss.edu.
authors.forename: Stephen O
authors.initials: SO
authors.lastname: Duke
authors.affiliation: National Center for Natural Products Research, University of Mississippi, MS 38677, USA. aali@olemiss.edu.
authors.forename: Abbas
authors.initials: A
authors.lastname: Ali
authors.affiliation: Department of Microbiology, Federal University of Minas Gerais, Belo Horizonte, MG 31270-901, Brazil. lhrosa@icb.ufmg.br.
authors.forename: Luiz H
authors.initials: LH
authors.lastname: Rosa
mesh_terms: D000330:Aedes / Q000187:drug effects; D031703:Agrostis / Q000187:drug effects; D000818:Animals; D029064:Araceae / Q000187:drug effects; D001938:Brazil; D004224:Diterpenes / Q000737:chemistry / Q000494:pharmacology*; D056727:Endangered Species; D006540:Herbicides / Q000737:chemistry / Q000494:pharmacology*; D007306:Insecticides / Q000737:chemistry / Q000494:pharmacology*; D018545:Lactuca / Q000187:drug effects; D019684:Magnoliopsida / Q000737:chemistry*; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology
chemical_list: D004224:Diterpenes; D006540:Herbicides; D007306:Insecticides; D010936:Plant Extracts
keywords: Velloziacea; diterpene; herbicide; natural products