Seasonal variability of the essential oil of Hesperozygis ringens (Benth.) Epling.

C G Pinheiro,C A A Almeida,L P Amaral,C M Machado,D T Silva,S J Longhi,C A Mallmann,B M Heinzmann

doi:10.1590/1519-6984.16314

Abstract

This study was developed to evaluate the effect of seasonality on the yield and chemical composition of the essential oil (EO) of Hesperozygis ringens (Benth.) Epling, a native species from the Brazilian Pampa. Leaves were collected from four specimens of a single population in each of the four seasons for a year and were extracted in triplicate by hydro-distillation for 2 hours. The yield of EO (% w/w) was calculated on fresh weight basis (FWB), and the 16 oil samples were analyzed by gas chromatography coupled to mass spectrometry (GC-MS) and gas chromatography with flame ionization detector (GC-FID). Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA) were used as statistical tools to evaluate differences in chemical composition. The highest yields were obtained in autumn, spring and summer (2.32-4.38%), while the lowest yields were detected in winter, ranging from 1.15 to 1.91%. Oxygenated monoterpenoids were the predominant class of chemical constituents in the EO obtained in all seasons, showing the highest contents in autumn and summer, and pulegone was identified as a major compound, whose contents varied between 54.13 and 81.17%. The EO samples were divided into three chemical groups by HCA and PCA and were assigned to the same group, except for the three samples gathered in winter. The results showed a seasonal influence on the yield and chemical composition of the EO.

Highlights

The Brazilian Pampa is located in the state of Rio Grande do Sul, southern Brazil, between 28o 00’ S and 34o 00’ S, and 49o 30’ W and 58o 00’ W
gas chromatography coupled to mass spectrometry (GC-MS) and gas chromatography with flame ionization detector (GC-FID) analysis allowed the identification of 37 compounds in the 16 Essential oils (EO) samples, which were classified into six different chemical classes
The yields were expressed in fresh weight basis because different authors have described EO loss in the leaves of Lamiaceae species and changes in the chemical composition of the oil due to drying processes (Argyropoulos and Müller, 2014; Sellami et al, 2012)

Summary

Introduction

The Brazilian Pampa is located in the state of Rio Grande do Sul, southern Brazil, between 28o 00’ S and 34o 00’ S, and 49o 30’ W and 58o 00’ W. Some studies have described a high production of essential oil by its leaves, with pulegone as major component (Ribeiro et al, 2010; Silva et al, 2014; Toni et al, 2014; Von Poser et al, 1996). This species is known by the vernacular name “espanta-pulga” (literally “to keep fleas away”) (Von Poser et al, 1996) and is used because of its anti-parasitic properties. The acaricidal, allelopathic, anesthetic and larvicidal activities of its EO have been already reported in the literature (Ribeiro et al, 2010; Silva et al, 2013, 2014; Von Poser et al, 1996)

Objectives

Methods

Conclusion