Synthesis of acetogenins and analogues searching for compounds with insecticidal activity against maize weevil and leaf-cutting ants

• Grant number: 13/13819-8
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Effective date (Start): November 01, 2013
• Effective date (End): September 30, 2014
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Organic Chemistry
• Principal Investigator: João Batista Fernandes
• Grantee: Keylla Utherdyany Bicalho
• Supervisor: Richard Charles Downie Brown
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Research place: University of Southampton, England
• Associated to the scholarship: 10/18832-4 - Biomonitored studies of Spondia dulcis (Anacardiaceae), Annona montana and Rollinia mucosa (Annonaceae) against Atta sexdens rubropilosa, Leucoagaricus gongylophorus and Sitophilus zeamais and development of nanoencapsulation processes., BP.DR

Abstract

Agriculture plays a key role in the economic development of Brazil and its participation in Brazilian GDP has been growing significantly mainly based on productivity. However various losses may occur during the production process mostly caused by pest's attacks. In order to obtain higher productivity it is necessary to develop techniques for controlling these pests such as leaf-cutting ants and maize weevil that have been causing serious losses in the national production. In this context arises the need of search for new compounds for the chemical control of these pests. An interesting strategy is the use of secondary metabolites produced by plants and other organisms. These metabolites can be used directly in the field as active principle or as model, "lead structures", to the development of new classes of insecticides. A class commonly reported in the literature with insecticidal activity is the acetogenins, isolated from the tropical plant family Annonaceae. These compounds act as inhibitors of complex I (NADH: ubiquinone oxidoreductase) in the mitochondrial electron transport chain promoting cellular apoptosis. Previous works involving the Annonaceae species Annona mucosa have shown strong insecticidal activity for this plant and its phytochemical studies led, so far, to the isolation of the acetogenin Rolliniastatin-1 as the majority component of the insecticidal fractions. The bioassay with this acetogenin against maize weevil resulted in 50% of mortality at a concentration of only 58,0 ppm and, besides the mortality value at the 10° day of experiment, was also observed loss of motor coordination symptoms in all subjects tested. In view of all these factors and the initial proposed for the PhD project, this PhD sandwich project proposes the development of new compounds with insectidal activity to maize weevil and leaf-cutting ants control using natural acetogenins as models. The proposal is based on total synthesis of bis-THF acetogenins able to be obtained from the methodologies developed in the organic synthesis group from University of Southampton under supervision of Dr. Richard Brown with subsequent evaluation of the acetogenin's insecticidal activity and its analugues as well as the intermediates of the synthetic route, which would allow a initial analisys of the effect of the structural differences among the compounds on the insecticidal activity of this class. (AU)