Essential Oils from Different Plant Parts of Eucalyptus cinerea F. Muell. ex Benth. (Myrtaceae) as a Source of 1,8-Cineole and Their Bioactivities

Abstract

Eucalyptus cinerea, known as silver dollar tree, has few descriptions in traditional medicine. Chemical composition and antimicrobial properties of the essential oils of leaves, flowers and fruits, collected seasonally, were determined by GC/MS and disk diffusion/MIC, respectively. 1,8-Cineole was the main compound, particularly in fresh leaves—Spring (74.98%), dried leaves—Spring (85.32%), flowers—Winter (78.76%) and fruits—Winter (80.97%). Other compounds were found in the aerial parts in all seasons: α-pinene (2.41% to 10.13%), limonene (1.46% to 4.43%), α-terpineol (1.73% to 11.72%), and α-terpinyl acetate (3.04% to 20.44%). The essential oils showed antimicrobial activities against bacteria and yeasts, with the best results being found for the dried autumn and winter leaves oils (MIC < 0.39 mg/mL) against Streptococcus pyogenes. For the other tested microorganisms the following MIC results were found: Staphylococcus aureus— Dried leaves oil from summer (0.78 mg/mL), Pseudomonas aeruginosa—Flowers oil from autumn and fruits oil from winter (1.56 mg/mL) and Candida albicans—Flowers oil from autumn and fruits oils from winter and spring (0.78 mg/mL).

Comparative evaluation of essential oils from Lippia javanica L leaf obtained by two methods and their effect on Artemia salina L

“…The higher yield in fresh leaves of the L. javanica negates what was reported by Silva et al [17], with the dried leaves of Eucalyptus cinera having a higher yield than the fresh ones. The yield of the essential oils of the leaf part of this plant was higher with hydrodistillation method compared with solvent-free microwave extraction method.…”

“…The significant low hatchability activity of essential oil of the fresh leaves of L. javanica extracted through HD might be due to the presence and yield of some inhibitory compounds such as humulene, 6-epi-shybunol, 3-Tetradecen-5-yne, (E) and Cyclopropanecarboxylic acid. Silva et al [17] and Bartololme et al [21] established the contributory effects of 3-tetradecen-5-yne and humulene as part of the compounds responsible for the anticancer and antitumoral activities of Bidens pilosa L. and Casearia sylvestris Sw.…”

Chemical&nbsp;Variability and&nbsp;Biological Activities of&nbsp;<em>Eucalyptus</em> spp. Essential Oils

“…The lowest reported contents were observed for plants from Argentina, 56.9% [85] and 62.1% [86]. EOs with content of 1,8-cineole superior to 70% were found from plants cultivated in Argentina, 88.5% [84] and 79.8% [75]; in Paraná State, Brazil, 83.6% [82] and 75.7% [81]; and in Tunisia, 79.2% [83] and 70.4% [80].…”

“…The essential oils of E. camaldulensis and E. tereticornis exhibited relevant activity against P. aeruginosa, presenting, respectively, izd = 15.5 mm and 16.0 mm [53]. The essential oils from E. cinerea were less active as shown by the izd = 7.0 mm when tested against P. aeruginosa [82].…”

Chemical Composition and Bactericidal Activities of the Leaf Essential Oil of Eucalyptus maculata Hook

“…The wood is slightly greasy and gum veins are common [7,8]. E. maculata is commonly used locally for treatment of various diseases and preservatives in food and drugs [9][10][11]. Essential oils are volatile complex mixture of organic compounds found in plants as secondary metabolites and characterized by a strong odour [12,13].…”