Effect of the essential oil from the latex of the fruit Mangifera indica L. on Tetranychus urticae Koch (Acari, Tetranychidae)

International audienceTetranychus urticae Koch is a cosmopolitan pest that causes damage to crops in protected farming activities in the semiarid region of the state of Pernambuco, Brazil. We investigated the lethal and sublethal effects of the essential oil from the latex of the mango fruit [Mangifera indica, Espada and Rosa (MESPA and MROSA) varieties] and selected monoterpenes on T. urticae. The yield of the MROSA oil was higher (9.22 ± 0.15%). The GC/MS analysis of the oils enabled the identification of 26 constituents. Terpinolene (70.14 ± 0.61%) was the major compound identified in the MESPA oil; β-pinene (38.22 ± 0.80%) was the major constituent of the MROSA oil, followed by terpinolene (29.44 ± 0.29%). The mite was more susceptible to the oils and constituents through fumigation, with no difference between the two varieties. By residual contact, the MROSA oil was 2.7-fold more toxic than the MESPA oil. Terpinolene was the most toxic constituent by fumigation, whereas β-pinene and α-pinene were the most active by residual contact. The selected compounds from M. indica also affected the behavior of the mite, exerting an influence on fecundity, feeding preference and egg-laying preference. The positive control (Azamax®) was more efficient at reducing the fecundity of the mite than the oils, but the MROSA oil was more toxic by fumigation and residual contact. The effects of fumigation and residual contact combined with the change in behavior may be a considerable advantage in the integrated management of T. urticae. For the practical use of these oils as novel acaricides, however, further investigations are needed to evaluate the effects on non-target organisms and the cost-benefit ratio for the formulation of a product to be used on protected crops in the semiarid region of the state of Pernambuco, Brazil

Chemical compositions of essential oil of piper species from atlantic forest of Amazonia, Brazil

Essential oils from the leaves of Piper japurense (Miq.) C. DC., P. coariense Yunk., P. auriculifolium Yunk., P. curtistilum C.DC., P. alatipetiolatum Yunk. and P. brevesanum Yunk. from the Amazon Forest (Brazil) were obtained through hydrodistillation. The chemical composition of the oils was determined using gas chromatography and mass spectrometry, which revealed the presence of 108 compounds representing 95.14%, 95.64%, 95.57%, 92.05%, 96.24% and 91.316% of the oils, respectively. All oils had an abundance of sesquiterpenes, except the oil from P. alatipetiolatum, which had a higher percentage of monoterpenes. The major components were α-eudesmol in the P. japurense (22.05%) and P. coariense (27.33%) oils, premnaspirodiene (32.26%) in the P. auriculifolium oil, caryophyllene oxide (28.69%) in the P. curtistilum oil, linalool (43.88%) in the P. alatipetiolatum oil and β-elemene (12.75%) in the P. brevesanum oil. Although the oils were composed of terpenes, the chemical analysis revealed qualitative and quantitative differences. This is the first report of the chemical composition of these six species of Piper that occur in the Amazonia biome in Brazil. © 2019 ACG Publications. All rights reserved

Relação entre a toxicidade de mono e sesquiterpenos identificados no óleo essencial de espécies dos gêneros Ocotea (Lauraceae) e Eugenia (Myrtaceae) sobre o ácaro rajado (Tetranycus urticae)

O presente trabalho tem como objetivo investigar a composição química do óleo essencial das folhas de Ocotea duckei e Ocotea glomerata e das folhas e frutos de Eugenia langsdorffii por CG-FID e CG-EM bem como avaliar a ação acaricida desses óleos essenciais e de seus compostos (de forma isolada e na forma de blendas) sobre o Tetranycus urticae. Os óleos das folhas das espécies do gênero Ocotea foram caracterizados pelo alto percentual de sesquiterpenos. Os principais compostos identificados foram o β-cariofileno (18,6±0,1%) e o valenceno (17,6±0,0%) no óleo da O. duckei e o Aromadendreno (17,3±0,6%) e β-cariofileno (14,6±0,3%) no óleo da O. glomerata. Os óleos das folhas e dos frutos da E. langsdorffii foram caracterizados pelo alto percentual de sesquiterpenos. Epilongipinanol (13,6±0,1%) e -eudesmol (12,3±0,2%) foram os componentes principais no óleo das folhas, enquanto que 10-epi--eudesmol (35,7±0,3%) e 1,10- di-epi-cubennol (15,6±0,3%) foram os constituintes majoritários identificados no óleo dos frutos. Todos os óleos testados foram tóxicos ao T. urticae. O óleo da O. duckei (CL50 = 0,52 μL L-1de ar) se mostrou 2,5 vezes mais tóxico do que o óleo da O. glomerata no teste de fumigação e 1,5 vezes mais tóxico do que o óleo da O. glomerata (CL50 = 7,22 μL/mL) no teste de contato residual. O óleo das folhas da E. langsdorffii (CL50 = 1,7 mL L-1 ar) foi 1,7 vezes mais tóxico do que o óleo dos frutos por fumigação, e 1,8 vezes menos tóxico por contato residual. A toxicidade por fumigação observada para todos os óleos foi muito inferior comparada com o controle positivo (eugenol). Entretanto, o efeito de contato residual dos óleos das folhas de O. duckei, O. glomerata e dos frutos da E. langsdorffii foram apenas 2,5; 4,0 e 6,7 vezes menor do que a do eugenol. A relação entre a propriedade acaricida dos constituintes e das blendas de todos os óleos investigados também é discutida.The present study aims to investigate the chemical composition of essential oil from leaves of Ocotea duckei and Ocotea glomerata and leaves and fruits of Eugenia langsdorffii by GC-FID and GC-MS and to evaluate the acaricide action of essential oils and their compounds (separately and as blends) on the Tetranycus urticae.The oils from the leaves of species of the genus Ocotea were characterized by high percentage of sesquiterpenes. The main compounds identified were β-caryophyllene (18.6 ± 0.1%) and valenceno (17.6 ± 0.0%) for the oil of O. duckei and aromadendrene (17.3 ± 0.6%) and β-caryophyllene (14.6 ± 0.3%) for the oil of O. glemerata. The oils from leaves and fruits of E. langsdorffii were characterized by high percentage of sesquiterpenes. Epi-longipinanol (13.6 ± 0.1%) and -eudesmol (12.3 ± 0.2%) were the main components of oil from the leaves, while 10-epi-- eudesmol (35.7 ± 0.3%) and 1,10-di-epi-cubennol (15.6 ± 0.3%) were the major identified in the oil of the fruits. All oils tested were toxic to T. urticae. The oil of O. duckei (LC50 = 0.52 mL L-1from air) showed 2.5 times more toxic than the oil of O. glomerata fumigation test and 1.5 times more toxic than the oil of O. glomerata (LC50 = 7.22 mL / mL) in the residual contact test. The oil from the leaves of E. langsdorffii (LC50 = 1.7 mL L-1 air) was 1.7 times more toxic than the oil of the fruit by fumigation, and 1.8 times less toxic by residual contact. The fumigation toxicity observed for all oils was much lower compared with the positive control (eugenol). However, the effect of residual contact of the oils from the leaves of O. duckei, O. glomerata and the fruits of E. langsdorffii were only 2.5, 4.0 and 6.7 times lower than that of eugenol. The relationship between property acaricide, constituents and the blends of all the oils investigated in this work is also discussed

Biosynthesis of pellucidin A in Peperomia pellucida (L.) HBK

Peperomia pellucida (L.) HBK (Piperaceae) (erva de jaboti) é uma herbácea amplamente encontrada nos trópicos e que possui diversas propriedades biológicas. Seus estudos fitoquímicos haviam demonstrado a presença da pellucidina A, uma rara dinorlignana ciclobutânica, que seria formada por acoplamento oxidativo de 2,4,5- triidroxi-estireno seguido de metilações. Nesse trabalho, foram caracterizados o ácido 2,4,5-trimetoxi-cinâmico, 2,4,5-trimetoxi-estireno, 2,4,5-trimetoxi-benzaldeído, dilapiol, 5,6,7-trimetoxi-flavona, sesamina, além da pellucidina A. Estudos de aspectos dinâmicos envolvidos na formação da pellucidina A incluíram a ontogenia e respostas à diferentes tratamentos como estresse hídrico, predação por herbívoros, ácido jasmônico e luz UV360. O tratamento com ácido jasmônico resultou num significativo incremento do dilapiol enquanto que, o tratamento sob luz UV360 resultou no aumento na produção da pellucidina A sugerindo um mecanismo de cicloadição [2+2] para sua biossíntese. A administração de diferentes precursores in vivo revelou que a L-[2-13C]- fenilalanina (0,75%), ácido [8-13C]-cinâmico (1,32%), ácido [8-13C]-ferúlico (0,51%), ácido 2,4,5-trimetoxi-[8-13C]-cinâmico (7,9%) e o 2,4,5-trimetoxi-estireno (13,3%) foram incorporados à pellucidina A. Ensaios de conversão enzimática indicaram a descarboxilação do ácido 2,4,5-trimetoxi-cinâmico em 2,4,5-trimetoxi-estireno enquanto que o 2,4,5-trimetoxi-estireno foi dimerizado em pellucidina A através da reação de cicloadição [2+2] sensibilizada pela presença da 5,6,7-trimetoxi-flavona (18,45%), tal qual a benzofenona (11,15%). Assim, sugere-se a sequência L-fenilalanina, ácido cinâmico, ácido 2,4,5-trimetoxi-cinâmico, 2,4,5-trimetoxi-estireno e pellucidina A, sendo a última etapa através de mecanismo fotoquímico tendo como sensibilizador a 5,6,7-trimetoxi-flavona.Peperomia pellucida (L.) HBK (Piperaceae) (erva de jaboti) is an herbaceous plant that is widespread in the tropics and have several biological properties. Previous reports described the presence of pellucidin A, a rare dinorlignan having the unique cyclobutane moiety, that was supposedly formed by oxidative coupling of the precursor 2,4,5-trihydroxy-styrene followed by methylations steps. In this study, a comprehensive phytochemical study resulted in the description of 2,4,5-trimethoxy-cinnamic acid, 5,6,7-trimethoxy-flavone, 2,4,5-trimethoxy-styrene, 2,4,5-trimethoxy-benzaldehyde, dillapiol and sesamin in addition to pellucidin A. Studies of the dynamic aspects involved in the formation of pellucidin A included changes during ontogeny and responses to different treatments such as drought stress, herbivory, jasmonic acid and UV360 light. The treatment with jasmonic acid resulted in a significant increase in dillapiol whereas treatment under UV360 light resulted in an increase in production of pellucidin A, suggesting that a cycloaddition [2+2] mechanism is involved in its formation. The in vivo administration of different precursors to plants of P. pellucida revealed that L-[2-13C]-phenylalanine (0.75%), [8-13C]-cinnamic acid (1.32%), [8-13C]-ferulic acid (0.51%) 2,4,5-trimethoxy-[8-13C]-cinnamic acid (7.9%) and 2,4,5-trimethoxy-[8-13C]-styrene (13.3%) were incorporated into pellucidin A. The enzymatic conversion assays indicated decarboxylation of 2,4,5-trimethoxy-cinnamic acid into 2,4,5-trimethoxy-styrene while the 2,4,5-trimethoxy-styrene was dimerized in the pellucidin A by cycloaddition reaction [2+2] sensitized by 5,6,7-trimethoxy-flavone (18.45%), as well as by benzophenone (11.15%). Thus, we suggest the sequence L-phenylalanine, cinnamic acid, 2,4,5-trimethoxy-cinnamic acid, 2,4,5-trimethoxy-styrene and pellucidin A, the last step being carried out by a photochemical mechanism having 5,6,7- trimethoxy-flavone as a sensitizer

First record of the chemical composition of essential oil of piper bellidifolium, piper durilignum, piper acutilimbum and piper consanguineum from the Brazilian Amazon forest

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. © 2018, Instituto Nacional de Pesquisas da Amazonia. All rights reserved