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Essential oils from the leaves and stems of Croton adenocalyx, C. grewioides, C. heliotropiifoliusand C. blanchetianusobtained through hydrodistillation were analyzed by GC-MS. We then investigated the lethal and sublethal effects of the Croton oils and 15 major constituents against Tetranychus urticae. β-Caryophyllene was the major component in the leaf and stem oils from C. heliotropiifoliusand C. adenocalyx. Spathulenol and (E)-anethole were the major constituents identified in the leaf and stem oils of C. blanchetianusand C. grewioides, respectively. The oil with the greatest lethal and sublethal effects was those from C. adenocalyx. Among the constituents β-caryophyllene and spatulenol were the most toxic to the mite, whereas eugenol and methyl eugenol were the most repellent. The toxicity and repellency of the Croton oils, particularly the oils from C. adenocalyx, demonstrate that these oils constitute a promising alternative to synthetic acaricides for use in the control of T. urticae.

Weed control in sustainable agriculture requires new bioherbicidal molecules to replace synthetic herbicides that have damaged the environment and generated resistance in weeds. This study was conducted to investigate the chemical composition of Eucalyptus globulus essential oil and to explore its bioherbicidal potential on the germination and radicle growth inhibition . The phytotoxic effects of E. globulus essential oil (1, 10 and 20 μL mL -1 ) were tested in comparison to those of the synthetic herbicide Glyphosate (1, 10 and 20 μL mL -1 ) in bioassays of germination and radicle growth of Lactuca sativa and the resistant weeds Avena fatua and Amaranthus hybridus . Gas Chromatography with Flame Ionization Detector and Gas Chromatography-Mass Spectroscopy analysis showed that major monoterpenes comprised 1,8-Cineole (86.94%), α-pinene (7.71%), d-limonene (2.65%), and p-cymene (1.48%). The seed germination and radicle length exhibited different degrees of inhibition in response to the concentration of E. globulus essential oil. At some concentrations, both the Glyphosate herbicide and the E. globulus essential oil demonstrated the same phytotoxicity against the resistant weeds A. fatua and A. hybridus. Essential oil bioactivity Lethal Concentration (LC 50 ) in the majority of cases was lowest for A. hybridus , followed by A. fatua and L. sativa. Based on the results, it can be concluded that E. globulus essential oil possesses phytotoxic potential and could be explored as a bioherbicide for resistant weeds management programs.

In the laboratory, were evaluated the effects (residual contact and feeding deterrence) of the essential oils from the leaves of Piper aduncum, Lippia sidoides and Schinus terebinthifolius, as well as eleven selected constituents and binary blends of oils in different proportions against 3rd instar larvae of Plutella xylostella (L.). The Piper oil demonstrated the greatest toxicity (LC50 = 0.31 µL/mL) and feeding deterrence (DC50 = 1.08 µL/mL) between oils tested. Dillapiole (LC50 = 1.01 µL/mL; DC50 = 1.10 µL/mL) and carvacrol (LC50 = 6.03 µL/mL; DC50 = 0.075 µL/mL) demonstrated the greatest toxicity and feeding deterrence between constituents tested, respectively. Based on the fractional effects indices for the blends, a synergistic interaction was found for the blend of the Lippia and Schinus oils at a proportion of 75 and 25%, respectively. The present findings indicate that this blend could be used in the control of P. xylostella, as the literature reports populations resistant to the active ingredient in the positive control, Premio®. Further studies are needed for the development of a new botanical insecticide based on the active ingredients in oils from L. sidoides and S. terebinthifolius to improve efficiency, stability and the cost-benefit in the control of P. xylostella.

Bemisia tabaci is a cosmopolitan pest responsible for causing harm to crops in the agricultural hub of Petrolina in the state of Pernambuco, Brazil. We investigated the lethal and sublethal effects of vapors from essential oils obtained through hydrodistillation of the peels of four species of Citrus and the latex from Mangifera indica (var. “rosa” and “espada”) on B. tabaci. The chemical analysis by Gas chromatography coupled to mass spectrometry of the oils led to the identification of 71 constituents, with limonene as the major component of the Citrus oils and terpinolene as the major component of the M. indica oils. B. tabaci was more susceptible to Citrus aurantiifolia (LC50 = 0.70 µL L-1 air) and C. limon (LC50 = 1.77 µL L-1 air) oils, which had the same level of toxicity. Citrus and M. indica oils also led to a reduction in the fecundity of the pest. The lethal and sublethal action of the constituents linalool, α-terpineol, α-pinene, β-pinene, terpinolene and limonene is also discussed. The toxicity of the oils investigated herein associated with the reduction in fecundity is a considerable advantage in the management of B. tabaci. However, for practical use of these oils as a novel insecticide to proceed, further research is required to address safety issues for human health and determine the formulation to improve the insecticidal potency, stability and cost-benefit ratio. RESUMO Bemisia tabaci é uma praga cosmopolita e responsável por causar prejuízos aos agricultores no Polo agrícola de Petrolina-PE. Os efeitos letal e subletal dos vapores dos óleos essenciais obtidos por hidrodestilação de quatro espécies de Citrus e do látex Mangifera indica var. rosa e espada, foram investigados sobre B. tabaci. Análise química por cromatografia gasosa acoplado à espectrometria de massa dos óleos permitiu a identificação de 71 constituintes, sendo limonene o principal dos óleos de Citrus e terpinolene para os de M. indica. A susceptibilidade de B. tabaci foi maior para os óleos de Citrus aurantiifolia (CL50 = 0,70 µL L-1 air) e C. limon (CL50 = 1,77 µL L-1 air), que apresentaram o mesmo nível de toxicidade entre si. Além da toxicidade, os óleos de Citrus e M. indica também atuaram na redução da fecundidade de B. tabaci. A ação letal e subletal dos constituintes, Linalol, α-terpineol, α-pineno, β-pineno, terpinoleno e limoneno também é discutida. A toxicidade associada com a redução da fecundidade dos óleos aqui investigados é uma grande vantagem para o manejo de B. tabaci. No entanto, para o uso prático destes óleos como novo inseticida, mais pesquisas são necessárias sobre questões de segurança para a saúde humana e formulação para melhorar a potencialidade inseticida, estabilidade e custo benéfico.

Essential oils from the leaves, stems, flowers and fruits of Melaleuca leucadendra growing in the state of Pernambuco, Brazil, were analyzed using gas chromatography-mass spectrometry (GC-MS). The effects of the oils and their major constituent were evaluated on the agricultural pests Tetranychus urticae and Plutella xylostella in different stages of development. The analysis revealed a M. leucadendra chemotype rich in (E)-nerolidol (81.78 ± 0.90 to 95.78 ± 1.20%). P. xylostella was more susceptible to the oils and major constituent than T. urticae. The fruit oil was 1.5-fold more toxic than the leaf oil to T. urticae eggs. (E)-Nerolidol was 5.5-fold and 4.5-fold more toxic to T. urticae adults than the leaf and fruit oils, respectively. Azamax® used as the positive control was more efficient than the oils and (E)-nerolidol against T. urticae. However, the oils and (E)-nerolidol were more toxic to P. xylostella than Azamax®.

This paper describes the construction of a polarimeter for the identification of chemical substances. The device was built with low-cost materials, measures the phenomenon of optical activity and has educational applicability. The measurement of optical activity is achieved through the measurement of the resulting polarized radiation in a photodiode connected to a voltmeter after passing through polarizing and analyzing filters.

Essential oils are natural compounds that have been widely studied in the control of various microbial diseases. In this context, Listeria monocytogenes and Enterococcus faecalis are disease-causing human pathogens that can lead to important health complications. This work aimed to evaluate effect of the essential oil (EO) of Tetragastris catuaba leaves, as well as its main compound in free and nanoemulsion-encapsulated forms, on the biofilm formation and planktonic growth of E. faecalis and L. monocytogenes. The chemical composition of the EO was identified using GC-MS, and the formulated nanoemulsions were evaluated for their physicochemical characteristics. The essential oil comprised 54 compounds, with β-caryophyllene being the major component (25.6%). The average size of nanoemulsions were 40.7 ± 0.07 nm for EO nanoemulsion and 41.7 ± 0.41 nm for β-caryophyllene nanoemulsion. The biological activities were observed mainly for the free EO and its nanoemulsion, with a significant reduction in biofilm formation and planktonic growth for both bacteria. While for β-caryophyllene, activity was observed only against E. faecalis, showing no activity against L. monocytogenes. These results indicate that T. catuaba EO may have promising applications in the prevention and control of contamination by bacterial biofilms. Furthermore, the formulated nanoemulsions proved to be an effective drug delivery system due to their stability and solubility in aqueous media.

Piper bellidifolium, Piper durilignum, Piper acutilimbum and Piper consanguineum are bushes that occur in the Amazon and are morphologically similar. With the aim of analyzing the chemical profile of the volatile constituents of these species, essential oils from the leaves were obtained through steam distillation and analyzed using gas chromatography-flame ionization detection (GC-FID) and gas chromatograph coupled to a mass spectrometer (GC-MS). The chemical analysis enabled the identification of 95 compounds representing 96.3 ± 0.6% of the P. bellidifolium oil, 95.5 ± 0.71% of the P. durilignum oil, 98.0 ± 1.0% of the P. acutilimbum oil and 96.1 ± 2.1% of the P. consanguineum oil. Although sesquiterpenes were the predominant chemical class in the oils of the four species, qualitative and quantitative differences were found in their chemical composition. The major constituents were (E)-nerolidol (20.3 ± 0.4%) in the P. bellidifolium oil, germacrene D (11.1 ± 0.3%) in the P. durilignum oil, and γ-eudesmol in both the P. consanguineum (18.6 ± 0.5%) and P. acutilimbum (7.5 ± 0.4%) oils. Despite their morphological similarity, a principal component analysis (PCA) of the GC-MS data clearly separated the four species according to the chemical profile of the essential oil extracted from their leaves. RESUMO Piper bellidifolium, Piper durilignum, Piper acutilimbum e Piper consanguineum são arbustos que ocorrem na Amazônia e são morfologicamente similares. Com o intuito de analisar o perfil químico dos constituintes voláteis dessas espécies, óleos essenciais das folhas foram obtidos por hidrodestilação e analisados por cromatografia gasosa - detector por ionização de chama (CG-FID) e cromatografia gasosa acoplada a espectrometria de massa (CG-EM). A análise química permitiu identificar 95 compostos, representando 96.3 ± 0.6% do óleo de P. bellidifolium; 95.5 ± 0.71% de P. durilignum; 98.0 ± 1.0% de P. acutilimbum e 96.1 ± 2.1% de P. consanguineum. Apesar dos óleos das quatro espécies terem sesquiterpeno como classe química predominante, diferenças qualitativas e quantitativas em sua composição química foram observadas. Os principais componentes encontrados foram: (E)-nerolidol (20.3 ± 0.4%) em P. bellidifolium; germacreno D (11.1 ± 0.3%) em P. durilignum; e γ-eudesmol nos óleos de P. consanguineum (18.6 ± 0.5%) e P. acutilimbum (7.5 ± 0.4%). Apesar da similaridade morfológica entre as espécies, uma análise de componentes principais (PCA) dos dados de CG-EM claramente separou as quatro espécies quanto ao perfil químico do óleo essencial extríado de suas folhas.

Diaphania hyalinata is an important pest in organic melon crops and has caused considerable harm to growers in northeastern Brazil. The aim of the present study was to determine the chemical composition of essential oils from Eugenia uniflora (pitanga) and Cinnamomum zeylanicum (cinnamon) as well as evaluate the repellant action, oviposition deterrence and effect on body mass caused by the oils and the constituents linalool and β-pinene in D. hyalinata. The essential oils from pitanga and cinnamon had a predominance of sesquiterpenes and phenylpropanoids, respectively. The pitanga oil was more effective as a larval repellent than the cinnamon oil and the constituents tested exhibited low repellent activity. In the evaluation of oviposition deterrence, the response of D. hyalinata exposed to the cinnamon oil did not vary with the distance between the treated and untreated leaf disks, but varied significantly when exposed to the pitanga oil. Linalool exhibited greater long-distance oviposition deterrence in comparison with β-pinene. In the experiments on body mass gain, second-instar larvae were more susceptible to the cinnamon oil than the pitanga oil and constituents tested. The findings suggest that these oils, especially the pitanga oil, could be an alternative for the control of D. hyalinata in the larval and adult phases. Further studies are needed to evaluate the effect on natural enemies and pollinating insects as well as the cost–benefit of the formulation of an insecticide for use on organic crops in northeastern Brazil.

Normal 0 21 false false false MicrosoftInternetExplorer4 Os oleos essenciais obtidos por hidrodestilacao das folhas e caules de Peperomia pellucida coletadas de um fragmento de Mata Atlântica no estado da Bahia, Brasil, foram analisados utilizando cromatografia gasosa e cromatografia gasosa-espectrometria de massa. Independentemente da parte da planta, sesquiterpenos foram a classe de compostos mais abundantes nos oleos, seguido de fenilpropanoides. Os principais constituintes do oleo das folhas foram ? -gurjuneno (11,34%), 1,10-di- epi -cubenol (11,27%), ( E )-cariofileno (8,71%) e dillapiole (8,50%), enquanto que carotol (9,77%), dillapiole (9,18%), trans - ? -guaieno (9,05%) e ( E )-cariofileno (8,53%) foram os principais constituintes do oleo de caule. A atividade dos oleos contra Tetranychus urticae foi avaliada por 24 h. O oleo do caule (LC 50 = 1 x 10 -2 µL/L of air) foi quatro vezes mais toxico do que o oleo de folha (LC 50 = 4 x 10 -2 µL/L of air), mas 2,5 vezes menos ativo do que o eugenol, o qual foi utilizado como o controle positivo .

Laboratory bioassays on fumigation, ovicidal and oviposition deterrence activity of the essential oil from Indigofera suffruticosa and its constituents [eugenol, (E)-asarone, dill apiole, (Z)-asarone, thymol, (E)-nerolidol and safrole] against Tetranychus urticae were carried out. Components of Indigofera leaf oil were characterized by gas chromatography (GC) ad mass spectrometry (GC-MS), which revealed the identification of 17 components, representing 97.7 ± 0.6% of the total oil, with a high percentage of phenylpropanoids (89.9 ± 0.5%), among which eugenol (45.6 ± 0.4%) and (E)-asarone (17.4 ± 0.2%) were major constituents. The ovicidal activity and oviposition deterrence tests revealed that the essential oil as well as its main compounds affected the oviposition and hatchability of mite eggs. Eugenol and thymol were the most potent compounds and were approximately 225-fold more potent than the oil. The acaricidal action exerted by sesquiterpenes and phenylpropanoids of the leaf oil is also discussed. The results suggest that the Indigofera oil and selected components associated with ovicidal activity and oviposition deterrence can serve as the basis for a promising agent that could be used in the formulation of a product for use against the T. urticae.

The essential oil from the leaves of Lippia gracilis was investigated for fumigant and residual activity against Tetranychus urticae (Acari: Tetranychidae) and Neoseiulus californicus (Acari: Phytoseiidae). The results were compared to eugenol, Ortus® and Azamax®, as positive controls. Gas chromatography (GC) and GC/mass spectrometry analysis enabled the identification of 28 compounds, accounting for 99.1 ± 0.6% of the essential oil. The major constituents were carvacrol (61%), p-cymene (11%) and thymol (11%). Mites were more susceptible to the oil in fumigant tests than in residual tests. Among the components, thymol and β-caryophyllene had the greatest fumigant and residual toxicity against T. urticae, respectively. The role of selected constituents (carvacrol, p-cymene, thymol, limonene, β-pinene, 1,8-cineole, terpinolene and β-caryophyllene) in the acaricidal properties of the L. gracilis essential oil is also discussed. Fumigant and residual effects of Lippia oil were more selective than eugenol with regard to a natural enemy of T. urticae, Neoseiulus californicus. Experiments under greenhouse conditions demonstrated greater toxicity of the Lippia oil in comparison to the positive control at 24, 48 and 72 h after treatment. The results suggest that Lippia oil is a good candidate for the formulation of a botanical acaricide for the integrated management of T. urticae.

Chemical analysis involving gas chromatography coupled to mass spectrometry of the essential oils of red and orange flowers from E. velutina revealed a predominance of phenylpropanoids in both samples. However, qualitative and quantitative differences were found in the compositions. (E)-Asarone (16.22 ± 0.23%) and (E)-caryophyllene (12.22 ± 0.11%) were identified as the major constituents of the essential oil from the red flowers, whereas (E)-caryophyllene (41.72 ± 1.65%) and eugenol (20.99 ± 0.21%) were identified as the major constituents of the oil from the orange flowers. Seventeen fatty acids were characterized in the red and black seeds. The fatty acid composition in the two chromatic variations had a high degree of similarity. Oleic acid (41.56 ± 1.33% and 46.12 ± 1.90% in the red and black seeds, respectively), palmitic acid (15.39 ± 0.16% and 12.33 ± 0.41%) and behenic acid (9.95 ± 0.14% and 12.10 ± 0.42%) were identified as the main fatty acids. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) enabled identifying significant differences in the chemical profile of the essential oils from the red flower and orange flower varieties of E. velutina. In contrast, PCA and HCA analysis revealed no significant differences in the fatty acid profile of the red and black seeds.

The aim of the present study was to evaluate the insecticidal potential of the essential oil from ripened and unripened fruit of the plant Schinus terebinthifolius and compare the toxic effects of artificial blends made with selected constituents of these oils [limonene, (E)-nerolidol, α-terpineol, β-terpineol, terpinolene, α-pinene and β-pinene] on the lesser grain borer, Rhyzopertha dominica (family -order). No statistically significant difference was found between the oils in the time periods tested (24, 48 and 72 h). Rhyzopertha dominica was more susceptible to limonene, terpinolene, α-pinene and β-pinene. Among the complete artificial blends tested at the proportions identified chemically, only that prepared with the constituents of the ripened fruit oil demonstrated toxicity on the same level as the essential oil. The analysis of the constituents revealed that limonene and α-terpineol contributed most to toxicity of the ripened fruit oil, whereas only limonene contributed to the toxicity of the unripened fruit oil. The present findings demonstrate that the toxicity of the ripened and unripened fruit oils cannot be attributed only to the individual toxicity of the constituents, but also the proportion at which these compounds are found and the types of interactions among the compounds. El objetivo del presente estudio fue evaluar el potencial insecticida de los aceites esenciales de los frutos maduros y no maduros de la planta Schinus terebinthifolius y comparar los efectos tóxicos de mezclas artificiales con los constituyentes seleccionados de estos aceites [limoneno, (E)-nerolidol, α-terpineol, β-terpineol, terpinoleno, α-pineno y β-pineno] en el barrenador de grano pequeño, Rhyzopertha dominica. La susceptibilidad de la plaga a los aceites aumentó con el tiempo. No se encontró diferencia estadísticamente significativa entre los aceites en los períodos de tiempo evaluados (24, 48 y 72 h). Rhyzopertha dominica fue más susceptible al limoneno, terpinoleno, α-pineno y β-pineno. Entre las mezclas artificiales completas, ensayadas en las proporciones caracterizadas químicamente, solamente la preparada con los componentes del aceite de fruta madura demostró toxicidad al mismo nivel que el aceite esencial. El análisis de los constituyentes reveló que el limoneno y el α-terpineol contribuyeron más a la toxicidad del aceite de fruta madura, mientras que unicamente el limoneno contribuyó a la toxicidad del aceite de fruta no madura. Los presentes hallazgos demuestran que la toxicidad de los aceites de frutas maduras y no maduras no puede atribuirse únicamente a la toxicidad individual de los constituyentes, sino también a la proporción en que se encuentran estos compuestos y al tipo de interaccion entre estos.

The essential oils from leaves, stems and roots of Piper caldense were analyzed by GC-MS. The antibacterial potential of the oils was evaluated against gram-negative bacteria and gram-positive bacteria. The major chemical constituents that were identified from various parts of this plant were α-cardinal, α-muurolol, tujopsan-2-β-ol and δ-cadiene in the leaves, valencene, pentadecane, elina-3,7-11-dieno α-terpineol in the roots and terpine-4-ol, α-terpineol, α-cadinol 2-β-ol in the stems. Tissue oils showed antibacterial activity against the bacteria tested except for Enterococcus faecalis. This is the first report of the biological activity and chemical composition essential oil of P. caldense.

The apolar fractions components of fruit latex of twelve species of Clusia belonging to four different taxonomic sections were examined by GC-MS. The latex of Clusia is characterised by large amounts of sesquiterpene hydrocarbons as major constituents like germacrene D: C. paralicola (44.28 %), C. criuva subsp. criuva (29.03 %); β-caryophyllene: C. fluminensis (35.61 %), C. lanceolata (36.39 %), C. hilariana (58.10 %); α-trans-bergamontene: C. spirictus-sanctensis (36.30 %); α-bulnesene: C. weddelliana (25.61 %); bicyclogermacrene: C. panapanari (25.93 %) and trans-β-farnesene: C. nemorosa (24.63 %), while C. grandiflora is composed of 42.16 % monoterpene hydrocarbons. Verbenone (31.91 %) was the major component. In contrast, C. rosea, C. grandiflora, C. lanceolata and C. criuva subsp. parviflora are rich in 3-methylcyclohexanone (19.56 %), hexadecanol (22.72 %), p-anisaldehyde (23.39 %) and octadecanol (26.81 %), respectively. This study suggests considerable chemical variation among the non-polar fractions of fruit latex of the twelve Clusia species.

Essential oils from the leaves of two species of the genus Ocotea that occur in the Atlantic Forest in the state of Pernambuco, Brazil, were analyzed using gas chromatography-mass spectrometry. The acaricidal activity of these oils as well as 11 selected components and blends were evaluated in fumigation and residual contact tests against the two-spotted spider mite (Tetranychus urticae). Sixty-seven constituents were identified, totaling 97.3 ± 0.3% and 97.8 ± 0.5% of the oils from O. duckei and O. glomerata, respectively. Sesquiterpene was the dominant class. The compounds β-caryophyllene (18.6 ± 0.1%) and aromadendrene (17.3 ± 0.6%) were the main constituents of the oils from O. duckei and O. glomerata, respectively. Acaricidal action varied depending on the method employed, species and chemical nature of the selected constituents. The mites were susceptible to the oils and chemical constituents using the fumigation method. The O. duckei oil was respectively 2.5-fold and 1.5-fold more toxic than the O. glomerata oil using the fumigation and residual contact methods. Among the selected constituents, β-caryophyllene was the most toxic, independently of the method employed. The individual toxicity of the selected compounds and their blends as well as the role of these constituents in the overall toxicity of the essential oils are also discussed.

The essential oils from fresh leaves of Protium bahianum collected bimonthly throughout one year were investigated using GC/FID and GC-MS analyses. The yield of essential oil ranged from 0.2 % to 1.6 %, with the maximum amount in summer (1.6 ± 0.1 %) and the minimum in winter (0.2 ± 0.1 %). A total of thirty-five compounds were identified. Sesquiterpene (from 57.0 % to 98.2 %) dominated the oil content, followed by monoterpenes and benzenoids. There was a significant difference for essential oil composition in the different seasons. For example, caryophyllene oxide (22.6 ± 0.0 % in July and 22.1 ± 0.1 % in May) and α-cadinene (25.3 ± 0.1 % in March) were found to be main compounds in winter season, while in the summer, aromadendrene (21.0 ± 0.1 % in January) and Caryophyllene oxide (20.3 ± 0.1 % in September) and α-pinene (19.1± 0.1 % in November) were the major components. The percentage found for two compound from germacrane group during seasonal variation were inversely proportional and an increase of ...

The essential oils of Protium bahianum fruit and leaves obtained through water distillation were analyzed by GC-FID and GC/MS, and their acaricidal activity was also evaluated using Tetranychus urticae as model. Twenty-nine components were identifed in the oils. The main component of the fruit oil was α-pinene (34.0%) whereas aromadendrene (20.3%) was the major component of the leaf oil. The leaf oil exhibited a higher lethality rate with LC50 of 3.5 μL/L of air after 24 h exposure. The fruits oil showed LC50 of 9.1 μL/L of air and was repellent at 1% concentration.

The volatile components of the fruits from nine collections of Clusia nemorosa G. Mey. from two municipalities (Tamandare: T1–3 and Cabo de Santo Agostinho: N1–3; G1–3) of the coastal region of Pernambuco, Northeast of Brazil, in two kind of soil, rocky rich in iron (N1–3) and sandy clays (T1–3 and G1–3), were analyzed by GC and GC/MS. The isolated oils were obtained in similar yields, 0.1–0.3 % (w/w) and 0.1–0.2% (w/w) in the samples from Taman- dare (T1–3) and Fortress Nazare (N1–3) and in the samples from Gaibu (G1–3), respectively. The oil samples can be characterized by the abundance of sesquiterpene hydrocarbons, while the percentage of oxygenated sesquiterpenes was higher in the samples collected in Tamandare (T1–3: 20.4—22.0%) and Gaibu (G1–3: 17.6–20.4%). Monoterpenes hydrocarbons were totally absent in all samples. All samples showed β-caryophyllene (37.3–48.6%) as the principal component. Based on the information of other major components, two subtypes of C. nemorosa growing wild in Pe...

The essential oils of leaves and stems of Croton grewioides Baill. of the “agreste” region of Pernambuco, Brazil, were obtained by hydrodistillation and analyzed by GC and GC/MS. Twenty-two components were identified, which represented 99.8% and 98.6% of the total constituents in the leaf and stem oil, respectively. Croton grewioides produced an oil with a predominance of phenylpropanoid compounds, whose principal component was (E)-anethole (65.5% in the leaf and 47.8% in the stem). Other major components found in the leaf oil were methyl eugenol (10.6%) and (E)-methyl isoeugenol (4.7%). Other components identified in the stem oil were (E)-methyl isoeugenol (30.0%), cadalene (8.4%) and methyl eugenol (4.6%). The insecticidal activity of C. grewioides was evaluated against Mexican bean weevils, Zabrotes subfaciatus (Boheman) resulting in a LC50 for the leaf oil, which was 3.4 times less than that obtained from the stem oil.

The chemical compositions of the essential oils from the leaves collected of Lippia gracilis Schauer at two localities in the bioma caatinga of Pernambuco were analyzed by GC and GC/MS, where a total of thirty-six compounds were identified in the oils from all the samples. The chemical profiles of samples from the same locations were the same having only relative changes in composition. But the chemical compositions of oils collected in the vicinity of Buique in the Agreste of Pernambuco were quite different from the ones collected in Ouricuri in the Sertao. The main components identified in samples from Buique were carvacrol (36.4–45.0%) and p-cymene (18.1–26.2%), while thymol (37.4%), γ-terpinene (14.9–20.5%) and 4-methoxy-acetophenone (10.1–12.4%) were the major components found in the specimen collected in Buique.

Essential oils obtained by hydrodistillation from stem and leaves of Cordia globosa (Jacq.) Hmb., Bonpl. et Kunth and Cordia curassavica (Jacq.) Roem. et Schult. were analyzed by GC/FID and GC/MS. The oil yield of C. globosa and C. curassavica was 0.5% and 1.1% for the stem and 0.6% and 1.0% for the leaves, respectively. Although they belong to the same genus, the chemical composition of the oils from two Cordia species was very different. The main components in the oil of C. globosa were: 1-endo-bourbonanol (20.2% in stem) and linalyl butyrate (14.7% in stem); β-caryophyllene (39.0% in leaves) and α-humulene (12.1% in leaves). Spathulenol (27.1% in stem), trans-sesquisabinene hydrate (11.0% in stem), viridiflorol (10.7% in stem), β-phellandrene (25.3% in leaves), cubebol (23.9% in leaves) and α-pinene (10.4 % in leaves) were the main constituents of the oils of C. curassavica.

The essential oils from two sources of resinous exudates of Protium bahianum obtained by hydrodistillation were analyzed by combinations of GC and GC/MS. Twenty-two and thirteen components were identified in the oils from fresh and aged resins, comprising 95.8 % and 98.6 %, of the oils, respectively. The aged resin oil contained a high percentage of oxygen-containing sesquiterpenes (85.4 %) with a high predominance of β-(Z)-santalol acetate (83.1 %). In contrast, no sesquiterpenes were detected in the fresh resin oil and it was constituted basically by monoterpenes hydrocarbons (42.4 %) and oxygen-containing monoterpenes (27.7 %), of which α-phellandrene (13.9 %) and terpinen-4-ol (7.4 %) were the major components, respectively. The acaricidal activities against Tetranychus urticae of the resin oil were also investigated. Both oils showed fumigant toxicity (mortality and fecundity), but only the aged resin oil induced repellence.

The essential oils of Lantana camara L. and L. fucata Lindl. leaves collected in the region of Mata Serrana in the municipality of Brejo da Madre de Deus in Pernambuco—Brazil were obtained by hydrodistillation and analyzed by GC and GC/MS. Twenty-five compounds were identified in L. camara, representing 99.4% of the leaf oil constituents, while 15 compounds were identified in L. fucata, representing 97.1% of the leaf oil constituents. The major compounds present in the oil of L. fucata were caryophyllene oxide (27.9%), gossonorol (18.2%), β-caryophyllene (12.3%) and bulnesol (10.8%), whereas those in the oil of L. camara were germacrene D (28.6%), germacrene D-4-ol (19.9%), β-caryophyllene (16.2%) and bicyclogermacrene (14.7%).

n-Hexane and dichloromethane extracts obtained from Laurencia dentroidea (Rhodophyta) and Canistrocarpus cervicornis (Phaeophyta) were investigated for their acaricidal and repellent properties against Tetranychus urticae under laboratory conditions. The two extracts displayed moderate toxicity and good repellent proprieties, and were significantly more toxic (36-fold) than the positive control (eugenol), whereas eugenol was tenfold more repellent than either seaweed extract. The sesquiterpenoid elatol (1) was isolated from L. dentroidea and the diterpenoid seco-dolastane (4 R,9 S,14 S)-4α-acetoxy-9β,14α-dihydroxydolast-1(15),7-diene (2) from C. cervicornis, the chemical structures of which were characterized by NMR spectroscopic data (1H and 13C) and by comparison with literature data. These compounds exhibited moderate toxicity, but a high degree of repellent activity against T. urticae. The findings suggest that marine natural products, specifically terpenes, can be employed for the development of new pesticides and become prototype agrochemical agents.

This present work addresses research on the discovery of new compounds from natural sources. It is based on a study of Mangifera indica leaf metabolism by the Tropidacris collaris grasshopper. We found that the grasshopper hydrolyzed the flavonoid isoquercitrin to quercetin when the O- glycosidic bond was broken and sugar released as a probable energy source for the insect. There was not, however, hydrolysis of the major compound in the leaves, mangiferin, which contains the C- glycosidic bond. All compounds were isolated and their chemical structure determined by UV, IR, MS, 1H and 13C NMR.

Published in Khimiya Prirodnykh Soedinenii, No. 4, July–August, 2012, pp. 622–623. Original article submitted May 12, 2011.

The compositions of the essential oils from unripe (UFr) and ripe (RFr) fruits of Schnus terebinthifolius were analyzed by GC and GC/MS. The major compound identified in both oils was limonene (UFr = 44.1 ± 1.3%; RFr = 31.8 ± 1.2%), followed by α-phellandrene (15.7 ± 0.4%) in the UFr oil and thujene (21.7 ± 0.9%) in the RFr oil. Repellent and toxicity activities of the two oils were also evaluated, and the results compared with eugenol. The UFr oil was more active in the fumigation tests (LC50 = 1.46 μL/L of air), whereas the RFr oil was more active in the sealed dishes (SD) than open dishes (OD) contact assay (LC50 = 3.04 μL/cm2) and not significantly different from eugenol. Both oils exhibited significant repellent activity comparable with that of eugenol. The results suggest that the repellent activity of these oils in association with its toxicity could be a great advantage for the integrated management of T. urticae.

Volatile components of essential oils from the leaves and stems of Croton jacobinensis, C. rhamnifolius, C. muscicapa and C. micans, which are medicinal plants found in the Caatinga biome of northeastern Brazil, were analyzed using GC and GC/MS. The acaricidal activity of these oils against Tetranychus urticae was evaluated using the fumigation method. Oil yields from the Croton species ranged from 1.1 +/- 0.0 to 0.6 +/- 0.0%, w/w, for leaves and 0.7 +/- 0.0 to 0.1 +/- 0.0% for stems. Sesquiterpenoids were dominant in all oils, except the stem oil from C. rhamnifolius, which exhibited a high monoterpene content, and the leaf and stem oils from C. muscicapa, which were rich in phenylpropanoids. The major volatile components of the leaf and stem oils from C. jacobinensis were (Z)-alpha-atlantone (24.3 +/- 0.4%) and trans-isolongifolanone (22.8 +/- 0.5%), respectively. The most abundant constituents detected in C. rhamnifolius were alpha-cedrene epoxide (23.3 +/- 0.1%) and caryophyllene oxide (21.9 +/- 0.0%) in the leaf oil, and camphor (16.6 +/- 0.5%) and tricyclene (12.8 +/- 0.1%) in the stem oil. Foenicolin was the main compound identified in the leaf (50.6 +/- 0.2%) and stem (72.7 +/- 0.6%) oils of C. muscicapa, while alpha-bulnesene (32.9 +/- 0.2%) and guaiol (17.9 +/- 0.7%) were the principal components of C. micans oils. These oils exhibited a high degree of toxicity in the fumigation assay. The stem oils from C. jacobinensis and C. rhamnifolius exhibited high lethality rates, with LC50 values of 0.3 and 0.2 microL/L of air after 24 h, respectively. The results suggest the potential use of stem essential oil, especially from C. rhamnifolius and C. jacobinensis, for the integrated control of Tetranychus urticae.