Encyclia cordigera is native from Central America tropical region, and Encyclia randii occurs at Brazilian Amazon environment domains. Floral concentrates from both Encyclia species were extracted, analyzed by gas chromatography-mass spectrometry, and identified compounds belong to terpenoids, phenylpropanoids, and fatty acid derivatives classes. Primary constituents of the E. cordigera floral scent were β-ionol (45.4%), terpinen-4-ol (12.4%), benzyl benzoate (5.6%), and indole (5.0%). (2E,6Z)-Farnesol (24.9%), heptanal (11.8%), (E)-nerolidol (9.4%), nonanal (6.4%), p-vinyl-guaiacol (6.0%), and phenylethyl benzoate (5.3%) have predominated in the floral scent of E. randii. From the olfactory standpoint, E. cordigera scent was previously characterized as a blend of ionone-floral and aromatic-floral notes. Very likely, E. randii scent presents the woody fragrance due to sesquiterpenes (2E,6Z)-farnesol and (E)-nerolidol and the fruity note from the aldehydes heptanal and nonanal. Floral perfume plays a fundamental role in attracting pollinating insects, whose symbiosis contributes to the appearance of chemical variations in orchid species.

The leaves and thin branches of Lippia grandis Schauer, Verbenaceae, are used for flavoring of food in the Brazilian Amazon, as substitute for oregano. In this study the constituents of the essential oil were identified and the antioxidant capacity and larvicidal activity of the oil and methanol extract and its sub-fractions were evaluated. A sensory evaluation was determined in view of absence of toxicity. The oil showed a yield of 2.1% and its main constituents were thymol (45.8%), p-cymene (14.3%), γ-terpinene (10.5%), carvacrol (9.9%) and thymol methyl ether (4.8%), totalizing 85%. The DPPH radical scavenging activity showed values for the EC50 between 9.0 and 130.5 µg mL-1 and the TEAC/ABTS values varied from 131.1 to 336.0 mg TE/g, indicating significant antioxidant activity for the plant. The total phenolic content ranged from 223.0 to 761.4 mg GAE/g, contributing to the antioxidant activity observed. The crude extracts inhibited the bleaching of β-carotene and the oil showed the greatest inhibition (42.5%). The oil (LgO, 7.6±2.4 µg mL-1) showed strong larvicidal activity against the brine shrimp bioassay. The sensory evaluation was highly satisfactory in comparison to oregano. The results are very promising for the use of L. grandis in seasoning and antioxidant products.

O óleo essencial das folhas e ramos finos frescos e secos de Hyptis crenata forneceu os seguintes rendimentos, 1,4% e 0,9%. Os constituintes voláteis principais foram ±-pineno (22,0%; 19,5%), 1,8-cineol (17,6%; 23,2%), ²-pineno (17,0%: 13,8%), cânfora (4,7%; 11,6%), limoneno (5,4%; 4,4%) e ³-terpineno (3,5%; 2,4%), totalizando mais de 70% nos óleos. A atividade de seqüestro do radical DPPH para o extrato metanólico (CE50, 16,7 + 0,4 µg/mL) foi comparável ao do BHT (19,8 ± 0,5 µg/mL) mostrando uma significante atividade antioxidante. Os óleos apresentaram baixa atividade. O teor de fenólicos totais (TP, 373,0 + 15,9 mg GAE/g) e equivalente trolox (TEAC, 226,8 + 0,5 mg TE/g) confirmaram a atividade antioxidante do extrato metanólico, que pode ser atribuída à presença de compostos fenólicos polares. No teste com larvas de camarão as concentrações letais para o óleo e extrato metanólico foram 6,7 + 0,2 µg/mL e 13,0 + 3,7 µg/mL, respectivamente, fornecendo importante evidência de suas atividade biológicas.

The essential oils of fresh and dried leaves and fine stems of Hyptis crenata furnished the following yields: 1.4% and 0.9%. The main volatile constituents were ±-pinene (22.0%; 19.5%), 1,8-cineole (17.6%; 23.2%), ²-pinene (17.0%; 13.8%), camphor (4.7%; 11.6%), limonene (5.4%; 4.4%) and ³-terpinene (3.5%; 2.4%), totalizing more than 70% in the oils. The DPPH radical scavenging activity (EC50, 16.7 + 0.4 µg/mL) of the methanol extract was comparable to BHT (19.8 ± 0.5 µg/mL) showing a significant antioxidant activity. The oils showed low activities. The amount of total phenolics (TP, 373.0 + 15.9 mg GAE/g) and trolox equivalent (TEAC, 226.8 + 0.5 mg TE/g) confirmed the antioxidant activity of the methanol extract that can be attributed to the presence of polar phenolic compounds. In the brine shrimp bioassay the lethal concentrations (LC50) for the oil and methanol extract were 6.7 + 0.2 µg/mL and 13.0 + 3.7 µg/mL, respectively, providing important evidence of their biological activities.

The aromatic flora of the Amazon has been inventoried for 30 years. In this sense, were made over 500 field trips to collect over 2500 plants and to obtain more than 2000 essential oils and aroma concentrates, all of them submitted to GC and GC-MS. This work led to the creation of a database for the aromatic plants of the Amazon, which catalogs general information about 1250 specimens. The database has allowed the publication of the chemical composition of the oils and aromas of more than 350 species, associated with a larger number of chemical types. The essential oils of many species offer optimum conditions for economic exploitation and use in national and international market of fragrances, cosmetics, agricultural and household pesticides.

Os óleos essenciais das folhas, ramos finos, galhos, cascas do caule e frutos de Croton palanostigma foram analisados por CG e CG-EM. Os componentes principais determinados no óleo das folhas foram linalol (25,4%), (E)-cariofileno (21,0%), metileugenol (17,2%) e β-elemeno (6,0%); no óleo dos ramos finos foram α-pineno (41,4%), limoneno (29,0%), sabineno (11,5%) e β-pineno (5,7%); no óleo dos galhos foram metileugenol (24,1%), (E)-metilisoeugenol (15,3%), α-pineno (11,2%) e (E)-cariofileno (8,5%); no óleo das cascas do caule foram a-pineno (31,6%), metileugenol (25,6%) e (E)-metilisoeugenol (23,7%); e no óleo dos frutos foram linalol (42,7%), metileugenol (16,3%) e β-elemeno (6,4%). Análise estatística mostrou que as folhas e os frutos apresentam significante similaridade entre si, assim como os galhos e as cascas do caule. Adicionalmente, o óleo obtido das cascas do caule possui elevada atividade larvicida sobre Artemia salina (CL50, 3,71 ± 0,01 mg mL-1).

The essential oils of leaves, twigs, branches, trunk bark and fruits of Croton palanostigma were analyzed by GC and GC-MS. The main compounds found in the oil of the leaves were linalool (25.4%), (E)-caryophyllene (21.0%), methyleugenol (17.2%) and β-elemene (6.0%); in the oil of the twigs were α-pinene (41.4%), limonene (29.0%), sabinene (11.5%) and β-pinene (5.7%); in the oil of the branches were methyleugenol (24.1%), (E)-methylisoeugenol (15.3%), α-pinene (11.2%) and (E)-caryophyllene (8.5%); in the oil of the trunk bark were a-pinene (31.6%), methyleugenol (25.6%) and (E)-methylisoeugenol (23.7%); and in the oil of the fruits were linalool (42.7%), methyleugenol (16.3%) and β-elemene (6.4%). Statistical analysis showed that the leaves and fruit, and the branches and trunk bark, have significant similarities between them. In addition, the trunk bark oil has high brine shrimp larvicidal activity (LC50, 3.71 ± 0.01 mg mL-1).

Os óleos essenciais da planta sub-aquática Conobea scoparioides (fresca e previamente seca) apresentaram rendimentos de 3,4 e 3,3%, respectivamente. Os principais constituintes identificados foram o éter metílico do timol (39,6 e 47,7%), timol (40,0 e 26,4%), α-felandreno (12,1 e 14,3%) e p-cimeno (1,5 e 1,7%), totalizando mais de 90% nos referidos óleos. A concentração de seqüestro do radical DPPH (CE50) dos óleos e extrato foi de 46,7 ± 3,6 µg mL-1 para a planta fresca (CsO-f), de 56,1 ± 2,4 µg mL-1 para a planta seca (CsO-d), e de 23,0 ± 2,2 µg mL-1 para o extrato metanólico (CsE-d). O valor do extrato é comparável ao BHT (19,8 ± 0,5 µg mL-1), usado como padrão antioxidante. O valor médio dos óleos é duas vezes menor, mas igualmente importante como agente antioxidante. O teor de Fenólicos Totais (TP, 124,6 ± 8,7 mg GAE per g) e o Trolox Equivalente (TEAC, 144,1 ± 4,9 mg TE per g) do extrato metanólico confirmaram a significativa atividade antioxidante de C. scoparioides. Da mesma forma, nos bioensaios com larva de camarão (Artemia salina) o valor médio da concentração letal dos óleos (CL50, 7,7 ± 0,3 µg mL-1) foi dez vezes maior que no extrato metanólico (CL50, 77,6 ± 7,1 µg mL-1) mostrando importante atividade biológica.

The essential oils of the sub-aquatic plant Conobea scoparioides (fresh and dried previously) showed yields of 3.4 and 3.3%, respectively. The main identified constituents were thymol methyl ether (39.6 and 47.7%), thymol (40.0 and 26.4%), α-phellandrene (12.1 and 14.3%) and p-cymene (1.5 and 1.7%), totalizing more than 90% of the oils. The DPPH radical scavenging activity (EC50) of the oils and extract was 46.7 ± 3.6 µg mL-1 in the fresh plant (CsO-f), 56.1 ± 2.4 µg mL-1 in the dried plant (CsO-d), and 23.0 ± 2.2 µg mL-1 in the methanol extract. The extract (CsE-d)value is comparable to BHT (19.8 ± 0.5 µg mL-1) used as antioxidant standard. The mean value of the oils is twice smaller but equally important as antioxidant agent. The mean amount of Total Phenolics (TP, 124.6 ± 8.7 mg GAE per g) and the Trolox Equivalent (TEAC, 144.1 ± 4.9 mg TE per g) of the methanol extract confirmed the significant antioxidant activity of C. scoparioides. Similarly, in the brine shrimp bioassay (Artemia salina) the mean value of the lethal concentration for the oils (LC50, 7.7 ± 0.3 µg mL-1) was ten times higher than the methanol extract (LC50, 77.6 ± 7.1 µg mL-1) showing important biological activity.

The aim of this study is to reevaluate the plant sources of the Amazon rosewood oil which have been named Aniba rosaeodora Ducke and Aniba duckei Kosterm. There is some disagreement on the exact botanical status of these species. Some Lauraceae specialists analyzing available material from both species concluded that there is no basis for regarding them as different. Based on our results we are confirming that the chemical composition of both species is quite different from that previously reported. So we are suggesting to bring back the previous botanical rosewood status as proposed by Adolph Ducke.

Os óleos essenciais das folhas e dos galhos de Cinnamomum zeylanicum coletada no município de Manaus, estado do Amazonas, foram obtidos por hidrodestilação e analisados através de CG-EM. Vinte e três constituintes foram identificados nas folhas, dos quais o eugenol foi o que apresentou maior porcentagem (60%). Nos galhos foram identificados trinta e seis componentes, com predominância dos monoterpenos alfa- e beta-pineno (9,9%; 3,5%), alfa-felandreno (9,2%), p-cimeno (6,2%), limoneno (7,9%), linalol (10,6%); os sesquiterpenos alfa-copaeno (3,3%), (beta )-cariofileno (6,7%), óxido de cariofileno (3,1%) e os alilbenzenos (E)-cinamaldeído (7,8%) e acetato de (E)-cinamila (9,7%).

The essential oils of the leaves and branches "of Cinnamomum zeylanicum, collected at Manaus, state of Amazonas, were obtained by hydrodistillation and analyzed by GC-MS. Twenty-three components were identified, of which eugenol, was the major (60%). Thirty-six components were identified in the branch oil, among them the monoterpenes alpha-pinene (9.9 %), beta-pinene (3.5 %), alpha phellandrene (9.2 %), p-cymene (6.2%), limonene (7.9%), linalool (10.6%) were the most abundant, followed by the sesquiterpenes alpha-copaene (3.3%), (beta)-caryophyllene (6.7%), caryophyllene oxide (3.1%) and the allybenzenes (E)-cinnamaldehyde (7.8%), (E)-cinnamyl acetate (9.7%).

Os óleos essenciais das folhas e dos galhos finos de Aniba canelilla (Kunth) Mez coletada na cidade de Manaus, AM, Brasil, foram obtidos por hidrodestilação e analisados por CG-EM. Quarenta e dois componentes foram identificados, dos quais 1-nitro-2-feniletano, como esperado, foi o que apresentou maior porcentagem (71,2%-68,2%).

The essential oil of the leaves and fine stems of Aniba canelilla (Kunth) Mez collected in the city of Manaus, AM, Brazil, were obtained by hydrodistillation and analyzed by GC/MS. Forty-two components were identified, of which 1-nitro-2-phenylethane, as expected, was the major (71.2%-68.2%).

Os constituintes voláteis obtidos dos extratos pentânicos das flores de Encyclia vespa e E. fragrans através de destilação-extração simultânea foram analisados por CG/EM. Os principais componentes voláteis identificados nas flores de E. vespa foram terpinen-4-ol (20,3%), verbenona (14,8%), trans-verbenol (13,6%) e a-pineno (11,8%). Os principais voláteis das flores de E. fragrans foram terpinen-4-ol (18,3%), (2Z,6E)-farnesol (15,4%) e trans-verbenol (10,2%).

The volatile constituents obtained from the pentane extract, using simultaneous distillation-extraction of the flowers of Encyclia vespa and E. fragrans were analysed by GC/ MS. The main volatile components identified in the flowers of E. vespa were terpinen-4-ol (20.3%), verbenone (14.8%), trans-verbenol (13.6%) and x-pinene (11.8%). The major volatiles of the flowers of E. fragrans were terpinen-4-ol (18.3%), (2Z,6E)-farnesol (15.4%) and trans-verbenol (10.2%).