The essential oil obtained from the stem bark of Croton urucurana Baillon (Euphorbiaceae) was analysed by GC and GC-MS. 83 compounds were identified and borneol (14.7%), bornyl acetate (5.2%), 1-isopropyl-7-methyl-4-methylene-1,3,4,5,6,8-hexahydro-2H-naphthalen-4a-ol (14.7%), sesquicineole (10.5%) and gamma-gurjunene epoxide (5.4%) were the main components. The EC50 value of the crude essential oil in the DPPH free radical scavenging assay was 3.21 mg mL-1. The fraction of the crude essential oil that presented antioxidant activity was purified by prep-TLC on silica gel. GC and GC-MS analysis revealed that alpha-bisabolol (38.3%), alpha-eudesmol (9.3%) and guaiol (8.2%) were the main components of the antioxidant fraction. The EC50 value measured for the bioactive oil fraction in the DPPH assay was 1.05 mg mL-1. The antimicrobial activity of the crude essential oil was assayed against seven Gram-positive and Gram-negative bacteria and three yeasts. Measured MIC values ranged from 1.25 to 10.00 mg mL-1.

The Schinus molle species produces high yields of volatile oils that can be obtained from leaves and fruits. It has been reported that S. molle oils have a variable chemical composition and biological activities, besides, they can be a source of bioactive compounds. In this work, studies were performed on the influence of extraction methods (hydrodistillation, steam distillation and fractional hydrodistillation) and seasonal variation, on the chemical composition (GC/MS and GC/FID analysis) of volatile oils (fruits and leaves) of this species. The comparison between the methods of hydrodistillation and steam distillation demonstrated that higher yields are obtained with hydrodistillation (1.2 % ± 0.2 % leaves, 1.8 % ± 0.3 % fruits). Increases in the concentrations of monoterpenes (50.7 % leaves and 70 % fruits) and sesquiterpenes (73.2 % leaves and 45.9 % fruits) are favored by the use of hydrodistillation and steam distillation techniques, respectively. Fractional hydrodistillation, using fractions collected at different extraction times (120 and 240 minutes), presented variations in the composition of oils from leaves and fruits. The 120 minutes fraction displayed the balanced distribution of monoterpenes and sesquiterpenes (46.8 % and 48.7 %, respectively), while 240 minutes fraction exhibited a high concentration of sesquiterpenes (80.5 %), with a predominance of epi-α-cadinol (40 %). The 240-minutes fraction was subjected to purification by preparative thin-layer chromatography and enabled isolation of the epi-α-cadinol (characterized by NMR). In the statistical analysis referring to the seasonal study of oil from leaves, 3 groups of compounds were characterized. Group I, corresponding to autumn, was characterized by the highest content of sesquiterpenes. Group II, corresponding to spring, was characterized by a higher percentage of monoterpenes. And group III, referring to summer and winter, was characterized by concentrations close to all the compounds identified.

The essential oils from the aerial parts of leaves, fruits and flowers of Zanthoxylum rhoifolium of Southern Brazil (Rio Grande do Sul), were analysed by GC, GC/MS, and chiral phase gas chromatography (CPGC). Forty-eight compounds were identified from the essential oils. The major constituents of the essential oil of the leaves were germacrene D (34 %) and bicyclogermacrene (23 %) and of the fruits, menth-2-en-1-ol (46.2 %), β-myrcene (30.2 %), (-)-linalool (15 %) and (-)-α-terpineol (8.45 %). β-Myrcene (65 %) and menth-2-en-1-ol (5.4 %) dominate the essential oil of the flowers. The oils of the leaves and fruits were bioactive with antibacterial activity against Staphylococcus aureus (Gram positive), and Klebsiella pneumoniae and Salmonella setubal bacteria (Gram negative) microorganisms, while the essential oil of the flowers was inactive.

The essential oils from the stem barks and leaves of Croton urucurana Baillon (Euphorbiaceae) were analyzed by GC-FID and GC-MS. 100 compounds were identified and borneol (14.7 %), bornyl acetate (5.2 %), cadina-4,10(14)-dien-1α-ol (14.7 %), sesquicineole (10.5 %) and γ-gurjunene epoxide (5.4 %) were the main components in essential oil from the steam barks. The oil from leaves was rich in sesquiterpenoids,mainly germacrene-D (15.2 %) and bicyclogermacrene (36.4 %). The in vitro cytotoxicity of the oils was evaluated against nine cancer cell lines and herbicidal effects against two seeds. The antimicrobial and antioxidant activities of the oils also were evaluated. The essential oil of stem bark was found to be more active than oil from leaves.