Performance, chemical composition and antibacterial activity of the essential oil of Ruta chalepensis and Origanum vulgare

Abstract

The antibacterial effectiveness of Origanum vulgare and Ruta chalepensis essential oils cultivated in three municipalities of Norte de Santander, Colombia, on gram positive and gram-negative bacteria was determined in vitro. The oil extraction process was carried out at zoey perfumery company by the steam dragging method from 5 kg of vegetable material, the oil yield obtained compared with the vegetable material collected was calculated using mathematical formulas and its chemical composition was determined by mass spectrometry since is an analytical technique with great potential that allows to elucidate the structure and chemical properties of molecules. For the determination of the minimum inhibitory concentration and the minimum bactericidal concentration of the extracted oils, the mother solution of 2.5 g/mL was prepared and from this solution, the different dilutions at concentrations from 1000 mg/mL up to 15.62 mg/mL were made. A suspension equal to tube 0.5 of the McFarland scale of each of the microorganisms (Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853) was then prepared with sterile saline solution and inoculated in microplates with volumes of diluted solution, soy tripticasa broth and dimethyl sulfoxide, was then incubated at 37 °C for 18 hours and proceeded to inoculate in Müeller-Hinton agar to verify its minimum bactericidal concentration. The results show that the yield of Origanum vulgare essential oil was 0.8% and for Ruta chalepensis 0.1%. The chemical analysis of the oils revealed the major components of Origanum vulgare such as β-mircene 1.6%, ∝-terpinene 15.7%, 1.8-cineol 3.8%, yterpineno 2.6%, terpine-4-ol 1.1%, timol methyl ether 17.4%, timol 30.6%, carvacrol 8.1%, trans-β-caryophyllene 6.3%, ∝-humulene 1%, cariophylene oxide 3.1% and Ruta chalepensis as nonanone 37.1%, undecanone 39.4%, nonanyl acetate 2.2%, decanone 2.8%. The results obtained show that essential oil of Ruta chalepensis at concentration of 500 mg/mL stop growth of Escherichia coli and seudomonas aeruginosa and at a concentration of 1000 mg/mL stop growth of S. aureus while the essential oil of Origanum vulgare was the most effective for the inhibition of all the microorganisms evaluated, requiring a concentration of 15.62 mg/mL for Escherichia coli and Staphylococcus aureus and for Pseudomonas aeruginosa, a concentration of 125 mg/mL was necessary. It is concluded that according to the chemical composition, materials of vegetable origin such as Ruta chalepensis and Origanum vulgare essential oils can be taken for the elaboration of products with potential in artisanal cosmetics and even in pharmaceutical products.