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

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.Keywords: Lamiaceae, "espanta-pulga", pulegone, oxygenated monoterpenoids. Variabilidade sazonal do óleo essencial deHesperozygis ringens (Benth.) Epling. ResumoEste estudo foi desenvolvido a fim de avaliar o efeito da sazonalidade no rendimento e composição química do óleo essencial (OE) de Hesperozygis ringens (Benth.) Epling., uma espécie nativa do Pampa brasileiro. Folhas foram coletadas de quatro indivíduos de uma mesma população, em cada uma das quatro estações de um ano, e foram extraídas em triplicada por hidrodestilação durante 2 horas. O rendimento do OE (% m/m) foi calculado considerando a base fresca (BF) e as 16 amostras de óleo foram analisadas por cromatografia gasosa acoplada à espectrometria de massas (CG-EM) e cromatografia gasosa com detector de ionização de chamas (CG-DIC). Análise Hierárquica de Cluster (AHC) e Análise de Componentes Principais (ACP) foram utilizadas como ferramentas estatísticas para avaliar as diferenças na composição química. Os maiores rendimentos foram obtidos no outono, primavera e verão (2,32-4,38%), enquanto que os menores foram detectados no inverno, variando de 1,15 até 1,91%. Os monoterpenoides oxigenados foram a classe predominante dos constituintes do OE obtido em todas as estações, apresentando os maiores teores no outono e no verão, e a pulegona foi identificada como o constituinte majoritário, cujos teores variaram entre 54,13 e 81,17%. As amostras de OE foram divididas em três grupos químicos por AHC e ACP e foram classificadas no mesmo grupo, com exceção de três amostras coletadas no inverno. Os resultados demonstraram influência sazonal no rendimento e...

Essential oils from Citrus x aurantium and Citrus x latifolia (Rutaceae) have anesthetic activity and are effective in reducing ion loss in silver catfish ( Rhamdia quelen )

“…The qualitative analysis of the EOs was performed by gas chromatography-mass spectrometry-total ion chromatogram using an Agilent 7890A gas chromatograph coupled with an Agilent 5975C mass selective detector and employing a HP-5MS column (5% phenyl, 95% methylsiloxane, 30 m × 0.25 mm i.d. × 0.25 mm) as described by Pinheiro et al (2016). The constituents were identified by comparison of the Kovats retention index and their mass spectra with data from the mass spectral library (NIST, 2010) and the literature (Adams, 2009).…”

“…The constituents were identified by comparison of the Kovats retention index and their mass spectra with data from the mass spectral library (NIST, 2010) and the literature (Adams, 2009). The quantitative analysis was performed with an Agilent 7890A gas chromatograph with flame ionization detection using the same parameters described by Pinheiro et al (2016). The percentage of the chemical components was based on peak area normalization.…”

Extracts of Hesperozygis ringens (Benth.) Epling: in vitro and in vivo antibacterial activity against fish pathogenic bacteria

“…Thus, EO and HEHR partially share chemical composition (menthone, pulegone, isopulegone, spathulenol and caryophyllene) which may be directly related to the antibacterial action against fish pathogenic bacteria (Pinheiro et al . ; Bandeira Junior et al . ).…”

“…; Pinheiro et al . ). However, only 65·06% of the hexane soluble fraction could be identified by gas chromatography.…”

“…Other substances such as menthone, menthol, isopulegone, spathulenol and caryophyllene were identified in the volatile fraction of HEHR and are part of the constituents frequently found in the EO of this species, except menthol (Pinheiro et al . ). Among the unidentified constituents, there may be compounds unreported in the literature and therefore require isolation for subsequent structural elucidation.…”