L-L Extraction Mixture Between Eucalyptus-Pelargonium Essential Oils and its Effectiveness on Klebsiella Pneumonieae

Objective: The synergistic or adjuvant effect on the antimicrobial effectiveness of pelargonium essential oil (PEO) in combination with eucalyptus essential oil (EEO) has been the objective of this work. Theoretical Framework: The small amounts of oil in pelargonium (difficultly extractable by vapor drag) have motivated a liquid PEO-liquid EEO (L-L) extraction. EEO has been used as an extractant for PEO, giving a final proportion of 5:2. Method: Both essential oils were obtained by steam stripping with water. Analysis by GC-FID chromatography gave 80.5% w/w of 1,8-cineole (eucalyptol), 3.05% w/w of limonene, 5.4% w/w of α-pinene, and antioxidant capacity of 76.0%. For the ME-E5P2 mixture, 56.4% of 1,8-cineole and 9.30% of citronellol were obtained from the essential oil of Pelargonium spp. with an antioxidant capacity of 78.6%. Due to the small amount of PEO (0.033% in the wet base of the plant) compared to EEO (5%), a direct soxhlet extraction of PEO with EEO as extractant was developed, until obtaining a proportion equivalent to EEO (5): PEO (2), so that volatility losses (typical of hydro distillation) were avoided. This mixture has been called the L-L EXTRACTION MIXTURE (ME-E5P2). Results and Discussion: In vitro, the effectiveness of ME-E5P2 against Klebsiella pneumoniae had better effectiveness against K. pneumoniae ATCC 13883 with a minimum bacterial concentration (MBC) of 60.5 mg/mL, a minimum inhibitory concentration (MIC) of 130 mg /mL and an excellent antimicrobial sensitivity (AMS) between 15.0 to 29.0 mm compared to Imipenem and oxacillin. It was found that the combination of the essential oils of Eucalyptus globulus Labill and Pelargonium spp. in a ratio of 5:2 has better antimicrobial effectiveness against Klebsiella pneumoniae. Research Implications: The practical and theoretical implications of this research are discussed, providing information on how the results can be applied or influence practices in the field of medicine and biology. Originality/Value: The relevance and value of this research is evident in providing an efficient and natural alternative to the indiscriminate use of chemical antibiotics, avoiding microbial resistance.