Preprint / Version 1

Study of the Chemical Composition and Biological Activity of the Essential Oil from Congona (Peperomia inaequalifolia Ruiz and Pav.)

Authors

  • Eduardo Valarezo Departamento de Química, Universidad Técnica Particular de Loja, Loja 110150, Ecuador
  • Mercedes Herrera-García Departamento de Química, Universidad Técnica Particular de Loja, Loja 110150, Ecuador
  • Paola Astudillo-Dávila Departamento de Química, Universidad Técnica Particular de Loja, Loja 110150, Ecuador
  • Isabel Rosales-Demera Departamento de Química, Universidad Técnica Particular de Loja, Loja 110150, Ecuador
  • Ximena Jaramillo-Fierro Departamento de Química, Universidad Técnica Particular de Loja, Loja 110150, Ecuador
  • Luis Cartuche Departamento de Química, Universidad Técnica Particular de Loja, Loja 110150, Ecuador
  • Miguel Meneses Departamento de Química, Universidad Técnica Particular de Loja, Loja 110150, Ecuador
  • Vladimir Morocho Departamento de Química, Universidad Técnica Particular de Loja, Loja 110150, Ecuador

Keywords:

biological activity, chemical composition, enantiomeric distribution, essential oil, Peperomia inaequalifolia

Abstract

The species Peperomia inaequalifolia, commonly known as congona, is a succulent herbaceous plant belonging to the Piperaceae family, which is used for different purposes in traditional medicine. In this study, the chemical composition, enantiomeric distribution, and biological activity of essential oil isolated from the leaves of this species was determined. Hydrodistillation was used to isolate the essential oil. Gas chromatography coupled to mass spectrometry was used to determine the qualitative composition, a gas chromatograph equipped with a flame ionization detector was used to determine quantitative composition, and gas chromatography on an enantioselective column was used to determine enantiomeric distribution. Antibacterial activity was determined using the broth microdilution method, for which we used three Gram-positive cocci bacteria, a Gram-positive bacilli bacterium, and three Gram-negative bacilli bacteria. 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical cations and 2,2-diphenyl-1-picrylhydryl (DPPH) radicals were used as reagents for determining the antioxidant activity of the essential oil. The spectrophotometric method was used to analyze the acetylcholinesterase inhibitory effect of the essential oil. The yield of leaves in essential oil was 0.16 ± 0.01% (v/w). Forty-three chemical compounds were identified in the essential oil, which represent 97.46% of the total composition. Sesquiterpene hydrocarbons were the most representative group, with 24 compounds (21.63%). The principal constituents were found to be elemicin (27.44 ± 1.35%), bisabolol <α-> (17.76 ± 1.38), myristicin (15.45 ± 0.86), methyl eugenol (6.22 ± 0.24), viridiflorene (6.81 ± 0.10), and safrole (6.68 ± 0.23). Three pairs of enantiomers were identified in the essential oil of Peperomia inaequalifolia. Essential oil presented a minimum inhibitory concentration (MIC) of 4000 μg/mL against Enterococcus faecalis, Enterococcus faecium, Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli. The antioxidant activity of the essential oil was strong according to the DPPH and ABTS methods, with a half radical scavenging capacity (SC50) of 293.76 ± 3.12 µg/mL and 226.86 ± 0.05 µg/mL, respectively. Additionally, the essential oil reported moderate anticholinesterase activity, with an IC50 of 43.93 ± 1.05 µg/mL. Keywords: biological activity, chemical composition, enantiomeric distribution, essential oil, Peperomia inaequalifolia

Author Biographies

Eduardo Valarezo, Departamento de Química, Universidad Técnica Particular de Loja, Loja 110150, Ecuador

Conceptualization, Resources, Writing – original draft, Project administration

Mercedes Herrera-García, Departamento de Química, Universidad Técnica Particular de Loja, Loja 110150, Ecuador

Methodology, Formal analysis, Investigation

Paola Astudillo-Dávila, Departamento de Química, Universidad Técnica Particular de Loja, Loja 110150, Ecuador

Methodology, Formal analysis, Investigation

Isabel Rosales-Demera, Departamento de Química, Universidad Técnica Particular de Loja, Loja 110150, Ecuador

Methodology, Formal analysis, Investigation

Ximena Jaramillo-Fierro, Departamento de Química, Universidad Técnica Particular de Loja, Loja 110150, Ecuador

Writing – original draft, Writing – review & editing, Visualization

Luis Cartuche, Departamento de Química, Universidad Técnica Particular de Loja, Loja 110150, Ecuador

Validation, Data curation, Supervision

Miguel Meneses, Departamento de Química, Universidad Técnica Particular de Loja, Loja 110150, Ecuador

Data curation, Writing – review & editing, Visualization

Vladimir Morocho, Departamento de Química, Universidad Técnica Particular de Loja, Loja 110150, Ecuador

Validation, Resources, Supervision

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