Terpenos e ácidos graxos de Dipteryx lacunifera Ducke

This paper describes the isolation of the furanocassane-type diterpene, named vinhaticoic acid, along with beta-farnesene and spatulenol from fruit shells of D. lacunifera. Structural determinations were accomplished by chemical derivatization and spectral analysis, including 1D and 2D NMR and X-ray crystallography. The fatty portion was extracted from the fruit kernels, transesterfied and analysed by HRGC/MS. Oleic acid (75.8 ± 4.3%) was the major component. Essential oil extracted from the fruit shells of D. lacunifera was analysed by HRGC/MS and nine sesquiterpenes were identified; beta-farnesene (48.6%) and spatulenol (21.61%) were the major constituents.

Composição química dos óleos essenciais das folhas de seis espécies do gênero Baccharis de "Campos de Altitude" da mata atlântica paulista

The essential oils from the leaves of six species of the Baccharis genus (B. dracunculifolia, B. microdonta, B. regnelli, B. schultzii, B. trimera, and B. uncinella), collected in the "Campos de Altitude" of the Atlantic Forest (SP), were extracted using hydrodistillation procedures and analyzed by GC and GC/MS. There was a predominance of sesquiterpenes in all studied oils as b-elemene in B. dracunculifolia and B. regnelli, a-humulene in B. trimera, g-gurjunene in B. schultzii, bicyclogermacrene in B. regnelli, d-cadinene in B. regnelli and B. uncinella, spathulenol in B. schultzii, caryophyllene oxide in B. microdonta and guaiol in B. uncinella. However, a high amount of monoterpenes was also observed in B. uncinella (a-pinene), B. regnelli (d-car-3-ene) and B. schultzii (limonene). The chemical compounds of the essential oils of B. schultzii, B. regnelli and B. microdonta are described for the first time in this work.

Composição e atividade antibacteriana dos óleos essenciais de Senecio crassiflorus var. crassiflorus

The essential oils of leaves, aerial and underground stems of Senecio crassiflorus var. crassiflorus were extracted by hydrodistillation and their analyses were performed by GC/MS. Qualitative and quantitative differences have been found between the analyzed parts. The main compounds of the essentials oils of the leaves were found to be oxygenated sesquiterpenes, while the oils from the aerial and underground stems showed sesquiterpene hydrocarbons as major constituents. Furthermore, the essential oils were tested against Staphylocccus aureus, Escherichia coli, Pseudomonas aeruginosa and Bacillus cereus. The essential oil of the leaves was shown to be the most active.

Influência da luz e da temperatura sobre a oxidação do óleo essencial de capim-limão (Cymbopogon citratus (D.C.) Stapf)

The identification of the chemical compounds of the essential oil was performed with a gas chromatograph coupled to a mass spectrometer. The oil was left in the presence and absence of light and submitted to different temperatures to evaluate its stability. The yields of the major compounds were evaluated every fifteen days. Citral and myrcene, the major compounds of the essential oil, were degraded over time in both the presence and absence of light, but temperature only influenced the degradation of myrcene.

Constituintes químicos voláteis das folhas e galhos de Zanthoxylum syncarpum Tull.

The essential oils of the leaves and twigs from Zanthoxylum syncarpum Tull. were examined by GC/MS and GC-FID. Variation in the oil composition relative to the harvesting time was also described. The major components in the leaves oils were limonene (23.1-47.3%) and myrcene (4.8-10.8%). In the oils of twigs, the main components were ar-curcumene (12.8-18.1%), E-β-farnesene (9.1-9.7%) and β-caryophyllene (9.2-9.3%). This paper describes for the first time the composition of the essential oil of the twigs from Z. syncarpum.

Óleos essenciais no Brasil: aspectos gerais, desenvolvimento e perspectivas

Essential oils are extracted by steam distillation of plants or cold pressing of citrus fruit pericarp. They are used in food, cosmetic, personal care and pharmaceutical industries. In Brazil, oils from orange and related products contribute to near 97% to the positive commercial performance of the sector. Predatory exploitation and the availability of new sources of raw materials, with more attracting prices, changed the paradigm. Prospective studies, sustainable use of Brazilian biodiversity, domestication of exotic species with commercial relevance, the use of breeding techniques and the development of new applications for essential oils are thematic lines, usually multidisciplinary, which have been prompting the expansion of the research on essential oils. This paper presents an analysis on essential oils balance trade from 2005 to 2008 and some historical data on research and production of essential oils in Brazil.

Variabilidade sazonal e biossíntese de terpenóides presentes no óleo essencial de Lippia alba (Mill.) N. E. Brown (Verbenaceae)

The essential oil of the leaves of Lippia alba chemotype linalool-1,8-cineol was extracted by hidrodistillation at different seasons and analyzed by GC/MS. Qualitative and quantitative variations in regard to the period of harvesting have been performed and the results were correlated with meteorological data. The essential oil yield varied from 0.33 to 0.67%. The chemical diversity of the constituents increased throughout the year, being 1,8-cineol and linalool the major components. Possible biosynthetic routes of mono and sesquiterpenoids present in the essential oil are discussed.

Variação sazonal da composição do óleo essencial de Myrcia salzmannii Berg. (Myrtaceae)

This work report the seasonal variation of composition of the volatile oils from leaves and from flowers of Myrcia salzmannii harvested in the sand dunes of Salvador, Bahia, northeastern region of Brazil in the years 2001 and 2003. The oils were analyzed by GC-FID and GC-MS being identified 49 components. Nine essential oil samples of leaves collected on different months and years and one sample of flowers were analyzed. β-Caryophyllene and α-humulene were the only compounds present in all of the samples being the first the majority compound.

Óleo essencial de limão no ensino da cromatografia em camada delgada

This paper describes a simple experiment employing the essential oil of limes which can be applied in undergraduate organic chemistry laboratory classes for the teaching of thin layer chromatography (TLC). The experiment consists in submit lime peel oil to TLC separation employing hexane and dichloromethane as the eluents and five different systems for visualization of the chromatogram. In one experiment it is possible to teach the different variables of the TLC technique. This experiment may also be performed following vapor distillation and liquid-liquid extraction technique in experimental classes.

Influência do armazenamento de folhas secas no óleo essencial de patchouli (Pogostemon cablin Benth.)

The aim of this work was to evaluate the influence of five storage times of dry leaves of two patchouli genotypes on its essential oil content and chemical composition. Harvest was realized four months after planting. Storage influenced essential oil content of genotype POG-002. Patchoulol was the majority compound. Storage of dry leaves increased significatively the content of the compounds α-bulnesene and germacrene A of genotype POG-021 and longicanfenilone, pogostol and patchoulol of POG-002. However, storage reduced significatively the content of the compounds cicloseichelene, β-cariofilene, α-guaiene, acifilene and α-bulnesene of the essential oil of genotype POG-002.

Efeito da temperatura do ar de secagem sobre o teor e a composição química do óleo essencial de Pectis brevipedunculata

Leaves and flower heads of P. brevipedunculata were submitted to four drying-air temperatures (room temperature, 40, 50 and 60 ºC). Room temperature (approximately 30 ºC) and higher temperature drying (50 and 60 ºC) had a deleterious effect on the essential oil content. The recommended drying-air temperature for the species is 40 ºC for it results in the same amount of essential oil observed in fresh cut plants. Overall, 13 components accounting for more than 92% of the total composition were identified. Citral was the major component, followed by α-pinene and limonene. The essential oil showed high toxicity against Artemia salina larvae.

Análise e discriminação de quimiotipos de Lippia graveolens H.B.K. da Guatemala por microextração em fase sólida, CG-EM e análise multivariada

SPME-GC-MS, PCA and HCA multivariate techniques were used in order to evaluate their applicability to discriminate the three chemotypes (thymol, carvacrol and mixed) described for L. graveolens of Guatemala. The leaves of L. graveolens are used for treatment of colds, bronchitis, and as seasoning for food preparations, yielding essential oil up to 4.34 %. Leaves of 35 individuals from eight populations, and eight composite samples were analyzed using a DVB/Carboxen/PDMS fiber and GC-MS. PCA and HCA were carried out using eight markers (p-cymene, cis-sabinene hydrate, linalool, terpinen-4-ol, thymol, carvacrol, (E)-caryophyllene and caryophyllene oxide). The three chemotypes of L. graveolens were satisfactorily discriminated.

Composição química e avaliação da atividade antimicrobiana do óleo essencial das folhas de Piper malacophyllum (C. Presl.) C. DC.

This work reports the chemical composition as well as the antibacterial, antifungal and antiparasitic activities of the leaf essential oil from Piper malacophyllum. The oil was extracted by hydrodistillation and analyzed by GC-FID, GC-MS and polarimetry. Among the 28 compounds identified, (+)-camphor was the major constituent. The essential oil showed activity against most of the microorganisms tested, especially antifungal action, with a MIC of 500 µg mL-1 against Trichophyton mentagrophytes and Cryptococcus neoformans. This is the first study reporting the composition and biological properties of leaf essential oil from P. malacophyllum.

Biomassa em aula prática de Química Orgânica Verde: cravo-da-índia como fonte simultânea de óleo essencial e de furfural

This work presents an optimized integrated experiment for isolation of clove bud essential oil, rich in eugenol, and subsequent utilization of the solid residue for furfural synthesis. The operationally simple laboratory protocols and utilization of water as a solvent in both operations, plus the use of biomass as the starting material for preparation of versatile intermediates in organic synthesis, make the experiments attractive for undergraduate experimental organic chemistry courses in the context of green chemistry. In addition, this is the first description of the use of biomass (clove bud) in the simultaneous preparation of two chemical feedstocks, eugenol and furfural, on experimental organic chemistry courses.

Volatile and non-volatile compounds and antimicrobial activity of Mansoa difficilis (Cham.) Bureau & K. Schum: (Bignoniaceae)

Essential oil from the leaves of Mansoa difficilis was analyzed by GC/MS. Oct-1-en-3-ol (49.65%) was the major compound, but diallyl di- and trisulfide were also present (0.85 and 0.37%, respectively), justifying the garlic-like odor of the crushed leaves. The hexane and methanol extracts of the leaves and stems afforded as main constituents a mixture of linear hydrocarbons, spinasterol, stigmasterol, ursolic and oleanolic acids, two apigenin derivatives and verbascoside. The hexane and methanol extracts of leaves were tested for antimicrobial activity against ten microorganisms. The hexane extract was active against both Psedomonas aeruginosa and Staphylococcus aureus.