A C Kimbaris

Publications (3)6.36 Total impact

• Article: Antibacterial activities of essential oils from eight Greek aromatic plants against clinical isolates of Staphylococcus aureus.

  A Alexopoulos, A C Kimbaris, S Plessas, I Mantzourani, I Theodoridou, E Stavropoulou, M G Polissiou, E Bezirtzoglou
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  ABSTRACT: Aromatic plants have been used widely to extend the shelf life of foods but at the same time research is undergoes for their properties as antibacterial agents in clinical use. Although there are promising results for the antimicrobial properties of various essential oils against environmental or food-isolated strains of Staphylococcus aureus, limited work has been done concerning these properties against clinical isolates of this pathogen. S. aureus is responsible for an increase number of nosocomial infections and at the same time exhibits increased resistance to synthetic agents. In this study, essential oils from eight aromatic plants common in Greece were isolated by hydrodistillation, analyzed by gas chromatography (GC) and GC/mass spectrometry (GC/MS) for their chemical components and tested for their antimicrobial activities against 24 clinical isolates of S. aureus. The methods used were disk diffusion and broth dilution in order to determine the Minimum Inhibitory Concentration (MIC). Our results showed that essential oils from Origanum vulgare and Origanum dictamnus were active against S. aureus when tested by disk diffusion, but exhibited increased MIC values (>256 mg/L) with the dilution method. In contrast, the reference strain NCTC 6571 showed to be extremely sensitive in most of the oils tested (MICs 0.25-32.0 mg/L) and resistant only to the essential oil from Ocimum basilicum. Therefore, there is no evidence of a potential clinical use for those essential oils and further research is needed in order to determine if they could substitute efficiently synthetic antibiotics or, perhaps be used in combination.
  Anaerobe 04/2011; 17(6):399-402. · 2.41 Impact Factor
• Article: Toxicity of citrus essential oils against Ceratitis capitata (Diptera: Tephritidae) larvae

  D.P. Papachristos, A.C. Kimbaris, N.T. Papadopoulos, M.G. Polissiou
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  ABSTRACT: Citrus peel essential oils are considered to constitute the most important resistance factor of citrus fruits against fruit flies. Essential oils were obtained from three sweet orange varieties, one bitter orange and one lemon variety. Yield, chemical composition and toxicity against neonates of the Mediterranean fruit fly were determined. Based on chemical analysis, the toxicity of commercially purchased major and minor components (monoterpenes and sesquiterpenes) of essential oils was determined. In addition, fractions were prepared to evaluate the role of minor components in the toxicity of crude essential oils. Limonene was by far the most abundant ingredient (96.2–97.4%) in all sweet orange varieties and in bitter orange, while the concentration of limonene was much lower in lemon essential oils (74.3%). Orange and bitter orange essential oils were more toxic than lemon essential oils. The toxicity of orange and bitter orange essential oils was similar to that of their major component limonene. In tests of commercially purchased chemicals, the oxygenated components of essential oils were more toxic than hydrocarbons but their low concentration in citrus essential oils could not affect the toxic activity of essential oils. The presence of -pinene and β-pinene seems to account for the lower toxicity of lemon essential oils in relation to other citrus essential oils. The importance of understanding the toxicity of essential oils in relation to their composition and their role regarding the resistance of citrus fruits to Ceratitis capitata infestation is discussed.
  Annals of Applied Biology 09/2009; 155(3):381 - 389. · 2.18 Impact Factor
• Article: Improvement of biodiesel production based on the application of ultrasound: Monitoring of the procedure by FTIR spectroscopy

  N. G. Siatis, A. C. Kimbaris, C. S. Pappas, P. A. Tarantilis, M. G. Polissiou
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  ABSTRACT: A novel application of ultrasounds is presented for the improvement of the efficiency of the production of FAME (or biodiesel) from materials not used so far for this purpose, such as seed cakes. The novelty of this work is the introduction of in situ derivatization assisted by ultrasounds (ultrasonically assisted extraction transesterification) for biodiesel production. Thus, the TG contained in solid material are extracted and immediately transesterified in a methanolic solution of 1 M NaOH in an ultrasonic field. The total yield of FAME from seeds that contain TG is greatly increased in most instances. In the seeds use in this work yields were increased from 46 to 85.5% for cotton, 67.2 to 93% for sunflower, and 43.2 to 83.5% for sesame. An FTIR methodology was developed to determine the percentage of FAME in the n-hexane layer of the reaction and thus, to monitor the reaction process. Overall advantages of the proposed methodology include the elimination of saponification, low reaction time, milder reaction conditions, and higher FAME yields.
  Journal of Oil & Fat Industries 12/2005; 83(1):53-57. · 1.77 Impact Factor