Gas chromatography coupled to mass spectrometry (GC-MS) characterization and evaluation of antibacterial bioactivities of the essential oils from Piper arboreum Aubl., Piper aduncum L. e Piper gaudichaudianum Kunth.

Ana Cristina A Da Silva,Camila F Bezerra,Edinardo F F Matias,Beatriz Helena L N S Maia,Wanderlei Do Amaral,Marcello Iriti,Maria Do S Costa,Ana Carolina Justino De Araújo,Thiago S De Freitas,Henrique D M Coutinho,Janaína E Rocha,Fábia F Campina,Aurea P Ferriani,Luiz E Silva

doi:10.1515/znc-2020-0045

Abstract

The objective of this study was to determine the chemical profile and to evaluate the antibacterial activity of the essential oils of Piper species and modulation of the antibiotic activity, using the microdilution method to determine the minimum inhibitory concentration. The chemical components were characterized by gas chromatography coupled to mass spectrometry, which revealed β-copaen-4-α-ol (31.38%), spathulenol (25.92%), and germacrene B (21.53%) as major constituents of the essential oils of Piper arboreum, Piper aduncum, and Piper gaudichaudianum, respectively. The essential oils analyzed in this study did not present a clinically relevant activity against standard and multiresistant Escherichia coli. However, in the case of multiresistant Staphylococcus aureus, there was a significant activity, corroborating with reports in the literature, where Gram-positive bacteria are more susceptible to antimicrobial activity. The essential oils modulated the effect of the antibiotics norfloxacin and gentamicin, having on the latter greater modulating effect; however, for erythromycin, no statistically significant effect was observed. In conclusion, the results obtained in this study demonstrated that the essential oils of the analyzed Piper species present an inhibitory effect against S. aureus and modulate antibiotic activity, most of which presents synergistic activity.

Highlights

Many medicinal plants have a large amount of bioactive compounds, such as phenolic compounds, terpenoids, nitrogen compounds, vitamins, and several other secondary metabolites, and since the beginning of mankind, they have been used for therapeutic purposes [1,2,3]
The chemical components were characterized by gas chromatography coupled to mass spectrometry, which revealed β-copaen-4α-ol (31.38%), spathulenol (25.92%), and germacrene B (21.53%) as major constituents of the essential oils of Piper arboreum, Piper aduncum, and Piper gaudichaudianum, respectively
The results obtained in this study demonstrated that the essential oils of the analyzed Piper species present an inhibitory effect against S. aureus and modulate antibiotic activity, most of which presents synergistic activity

Summary

Introduction

Many medicinal plants have a large amount of bioactive compounds, such as phenolic compounds, terpenoids, nitrogen compounds, vitamins, and several other secondary metabolites, and since the beginning of mankind, they have been used for therapeutic purposes [1,2,3]. Studies show that several phytochemicals present in medicinal plants have anti-inflammatory, antitumoral, antibacterial, or viral action [4]. The genus Piper widely distributed in subtropical regions is known for its aromatic herbs [5]. Many species of this genus produce essential oils which contain monoterpenes (germacrene A, α-pinene), sesquiterpenes (germacrene B, germacrene D, α-humulene, β-copaen-4-α-ol) , phenylpropanoids The species Piper arboreum Aubl., popularly known as “pau-de-angola”, “jaborandi”, chilli pepper, has antifungal, trypanocidal, antibacterial, and antioxidant activities [7,8]. Piper aduncum L., popularly known as “jaborandi do mato”, monkey pepper, “jaboti” [9] herb possesses antifungal [10], antiprotozoal [11], and insecticide activities [12]. Other studies report biological activities such as fungicide [14], insecticidal, anti-inflammatory, larvicidal, and analgesic effects [15,16]

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