Larvicidal Activity against Aedes aegypti and Chemical Characterization of the Inflorescences of Tagetes patula.

Letícia Maria Krzyzaniak,Ana Luiza Sereia,Gisely Cristiny Lopes,Denise Brentan Silva,João Carlos Palazzo De Mello,José Roberto Pinto De Souza,Gean Panizzon,Daniela Cristina De Medeiros,Eneri Vieira De Souza Leite-Mello,João Antonio Cyrino Zequi,Cláudio Roberto Novello,Tânia Mara Antonelli-Ushirobira

doi:10.1155/2017/9602368

Abstract

The crude acetone extract (CAE) of defatted inflorescences of Tagetes patula was partitioned into five semipurified fractions: n-hexane (HF), dichloromethane (DF), ethyl acetate (EAF), n-butanol (BF), and aqueous (AQF). BF was fractionated by reversed-phase polyamide column chromatography, obtaining 34 subfractions, which were subjected to HSCCC, where patuletin and patulitrin were isolated. CAE and the fractions BF, EAF, DF, and AQF were analyzed by LC-DAD-MS, and patuletin and patulitrin were determined as the major substances in EAF and BF, respectively. BF was also analyzed by HPLC and capillary electrophoresis (CE), and patulitrin was again determined to be the main substance in this fraction. CAE and the semipurified fractions (750, 500, 300, 100, and 50 mg/L) were assayed for larvicidal activity against Aedes aegypti, with mortality rate expressed as percentage. All fractions except AQF showed insecticidal activity after 24 h exposure of larvae to the highest concentration. However, EAF showed the highest activity with more than 50% reduction in larval population at 50 mg/L. The insecticidal activity observed with EAF might have been due to the higher concentration of patuletin present in this fraction.

Highlights

Aedes aegypti (Linnaeus, 1762) is an anthropophilic and domicile mosquito, and it is the main vector for dengue viruses in the Americas
An exsiccate is deposited at the Herbarium of the Universidade Estadual de Maringa (HUEM) under number 21907, and the identification was provided by Professor Dr Jimi Nakajima at the Institute
Among the semipurified fractions obtained from crude acetone extract (CAE) of the inflorescences of T. patula, BF showed a higher yield of the flavonoids patuletin and patuletin-7-O-β-glycoside

Summary

Introduction

Aedes aegypti (Linnaeus, 1762) is an anthropophilic and domicile mosquito, and it is the main vector for dengue viruses in the Americas. This mosquito puts half of the world’s population at risk with a 30-fold increase in incidence in the past 50 years in more than 100 endemic countries [1, 2]. There is currently a great deal of interest in alternative methods and selective principles for the control of mosquitoes with less environmental damage [7]. In this sense, substances extracted from plants present a great perspective for the control of Ae. aegypti

Objectives

Methods

Conclusion