Evaluation of seasonal chemical composition, antibacterial, antioxidant and anticholinesterase activity of essential oil from <i>Eugenia brasiliensis</i> Lam.

<div><p>This study describes the seasonal composition and the antibacterial, antioxidant and anticholinesterase activity of the essential oil from <i>Eugenia brasiliensis</i> leaves. Analysis by using GC allowed the identification of 40 compounds. It was observed that the monoterpenes varied more (42%) than the sesquiterpenes (14%), and that the monoterpene hydrocarbons suffered the greatest variation throughout the year (64%). Major compounds were spathulenol in the spring (16.02 ± 0.44%) and summer (18.17 ± 0.41%), τ-cadinol in the autumn (12.83 ± 0.03%) and α-pinene (15.94 ± 0.58%) in the winter. Essential oils were tested for their antibacterial activity, and the best result was obtained from the autumn oil, with MIC = 500 μg mL^− 1 against <i>Staphylococcus saprophyticus</i> and <i>Pseudomonas aeruginosa</i>. Antioxidant activity was evaluated using DPPH, lipid peroxidation and iron-reducing power assays, as well as the anticholinesterase activity. Both tests showed a weak performance of the essential oils.</p></div

Characterisation of phenolic compounds of the ethyl acetate fraction from <i>Tabernaemontana catharinensis</i> and its potential antidepressant-like effect

<p>This study evaluates the antidepressant-like effect and analysed the qualitative and quantitative 74 phenolic standards of ethyl acetate fraction from <i>Tabernaemontana catharinensis</i> leaves. Acute administration of fraction in mice reduced the immobility time in forced swimming and tail suspension tests confirming its antidepressant-like activity. The anti-immobility effect elicited by this fraction was prevented by the pretreatment of mice with PCPA (100 mg kg⁻¹), ketanserin (5 mg kg⁻¹), SCH 23,390 (0.05 mg kg⁻¹) or yohimbine (1 mg kg⁻¹). A sub effective dose of the fraction produced a synergistic effect with fluoxetine (5 mg kg⁻¹). Chromatographic analysis identified 4-hydroxybenzoic and <i>p</i>-coumaric acids in the ethyl acetate fraction from <i>T. catharinensis</i>. Capillary electrophoresis presented 7.34 ± 0.02 mg g⁻¹ of <i>p</i>-coumaric acid concentration in the fraction. Therefore, it is possible that antidepressant-like effect elicited by ethyl acetate fraction from <i>T. catharinensis</i> be dependent on the <i>p</i>-coumaric acid.</p

Chemical composition and evaluation of the antimicrobial activity of the essential oil from leaves of <i>Eugenia platysema</i>

<p>This study describes the qualitative and quantitative chemical composition and evaluates the antibacterial activity of essential oil from <i>Eugenia platysema</i> leaves. Analysis by GC–FID and GC–MS allowed the identification of 22 compounds. Different from the other species of the <i>Eugenia</i> genus, the major compound found in the essential oil was the diterpene phytol (66.05%), being this the first report of the presence of this compound in the essential oils from <i>Eugenia</i> genus. The sesquiterpene elixene was the second most concentrated compound in the studied essential oil (9.16%). The essential oil from <i>E. platysema</i> was tested for its antibacterial activity against cell-walled bacteria and mollicute strains of clinical interest using the microdilution broth assay. The results showed that the essential oil of <i>E. platysema</i> was inactive until 1000 μg mL⁻¹ against tested bacteria.</p

Antimycoplasmic activity and seasonal variation of essential oil of <i>Eugenia hiemalis</i> Cambess. (Myrtaceae)

<p>The purpose of this work was to study the chemical composition and antimycoplasmic and anticholinesterase activities of the essential oil of <i>Eugenia hiemalis</i> leaves collected throughout the year. A total of 42 compounds were identified by CG, and are present in almost every seasons. Sesquiterpenes were dominant (86.01–91.48%), and non-functionalised sesquiterpenes comprised the major fraction, which increased in the summer; monoterpenes were not identified. The major components were spathulenol (5.36–16.06%), δ-cadinene (7.50–15.93%), bicyclogermacrene (5.70–14.24%) and β-caryophyllene (4.80–9.43%). The highest oil yield was obtained in summer and autumn. Essential oils presented activity against three evaluated <i>Mycoplasma</i> strains, but no activity was observed in the anticholinesterase assay.</p