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The leaves of Piper auritum Kunth ('Hoja Santa') have been consumed for centuries by native people of central and southern Mexico as a fresh vegetable or condiment. Herein we present the result of the 1 H-NMR metabolomics profiling of three accessions of P. auritum harvested in three different provinces of Mexico (Puebla, Tlaxcala, and Oaxaca). The volatile content associated with the flavoring properties of the plant was also determined by GC/MS. The non-targeted metabolome of these samples revealed that P. auritum is a source of free essential amino acids such as isoleucine, leucine, threonine, valine, histidine, phenylalanine, and tryptophan as well as organic acids, free monosaccharides, and valuable nutraceuticals such as trigonelline, Myo-inositol, betaine, and choline. Principal component analysis and orthogonal partial least squares discriminated analysis of the metabolites found in P. auritum revealed trigonelline as the main differential compound found in the three studied accessions, suggesting this metabolite as a possible chemical marker. According to these statistical approaches, 60 % of the differential metabolites were provided by Oaxaca samples, suggesting that leaves harvested in this province have better (p<0.05) nutritional properties than the other samples analyzed. Nevertheless, the high abundance of the anti-nutrient safrole (90 %) in the volatile fraction, advises the potential toxicity of P. auritum consumed in Oaxaca. On the other hand, samples harvested in the northern highlands of Puebla, contained the lowest levels of safrole (30 %) and acceptable levels of nutrients and nutraceuticals including choline. From the three groups of studied plants, those harvested in the northern highlands from Puebla, could be considered safer for human consumption than the other analyzed accessions.

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The species Piper hispidinervum, Piper aduncum, and Piper affinis hispidinervum have essential oils with high levels of safrole, dillapiole, and sarisan, respectively. Safrole is important for pharmaceutical and chemical industries, while dillapiole and sarisan are promising compounds to control insects and fungi. These species are very similar morphologically and their taxonomy is controversial. Divergent hypotheses consider P. aduncum and P. hispidinervum either as a single species or as distinct taxa, while P. affinis hispidinervum is inferred to be a natural hybrid or a chemotype of P. hispidinervum. Delimiting the taxonomic boundaries would be helpful for germplasm conservation and breeding programs. This study aimed to undertake a detailed analysis of P. aduncum, P. hispidinervum, and P. affinis hispidinervum karyotype and rDNA sites. Genomic in situ hybridization (GISH) was used to establish genomic homology among species and to test the natural hybridization hypothesis for origin of P. affinis hispidinervum. Karyotype traits were similar for all three species: 2n = 26 small chromosomes, predominantly metacentric. All three species exhibited CMA+ bands on the secondary constriction of chromosome pair 4. A size-heteromorphic 35S rDNA site was co-localized with the CMA+ band. A 5S rDNA site was located in the proximal region of chromosome pair 7. The patterns of genomic hybridization revealed that the repetitive DNA fraction of the species is highly similar in terms of proportion of genome, sequence type, and distribution. Our findings did not allow us to differentiate the three species and point to the importance of deeper genomic studies to elucidate the taxonomic controversy.

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Bioinsecticides are regarded as important alternatives for controlling agricultural pests. However, few studies have determined the persistence of these compounds in stored grains. This study aimed at optimizing and validating a fast and effective method for extraction and quantification of residues of safrole (the main component of Piper hispidinervum essential oil) in cowpea beans. It also sought to assess the persistence of this substance in the grains treated by contact and fumigation. The proposed method used headspace solid-phase microextraction (HS-SPME) and gas chromatography with a flame ionization detector (GC/FID). Factors such as temperature, extraction time and type of fiber were assessed to maximize the performance of the extraction technique. The performance of the method was appraised via the parameters selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy. The LOD and LOQ of safrole were 0.0057 and 0.019 µg kg-1, respectively and the determination coefficient (R2) was >0.99. The relative recovery ranged from 99.26 to 104.85, with a coefficient of variation <15%. The validated method was applied to assess the persistence of safrole residue in grains, where concentrations ranged from 1.095 to 0.052 µg kg-1 (contact) and from 2.16 to 0.12 µg kg -1 (fumigation). The levels measured up from the fifth day represented less than 1% of the initial concentration, proving that safrole have low persistence in cowpea beans, thus being safe for bioinsecticide use. Thus, this work is relevant not only for the extraction method developed, but also for the possible use of a natural insecticide in pest management in stored grains.

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In this study, the essential oil (EO) from Laurelia sempervirens was analyzed by GC/MS and safrole (1) was identified as the major metabolite 1, was subjected to direct reactions on the oxygenated groups in the aromatic ring and in the side chain, and eight compounds (4 to 12) were obtained by the process. EO and compounds 4-12 were subjected to biological assays on 24 strains of the genus Saprolegnia, specifically of the species 12 S. parasitica and 12 S. australis. EO showed a significant effect against Saprolegnia strains. Compound 6 presents the highest activity against two resistant strains, with minimum inhibitory concentration (MIC) and minimum oomyceticidal concentration (MOC) values of 25 to 100 and 75 to 125 µg/mL, respectively. The results show that compound 6 exhibited superior activities compared to the commercial controls bronopol and azoxystrobin used to combat these pathogens.

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Resumen La leishmaniasis es una enfermedad con una alta incidencia en el ser humano, que puede ser controlada, pero como los tratamientos tienen efectos secundarios importantes se han realizado estudios de diversas plantas con el fin de encontrar compuestos con actividad antileishmaniásica que presenten pocos efectos nocivos para el ser humano. El presente estudio consistió en realizar un tamizaje fitoquímico de la planta, para identificar la presencia de cumarinas, terpenos, triterpenos y azúcares reductores. El objetivo fue encontrar componentes químicos puros con actividad contra el parásito Leishmania sp. Por tal razón se purificaron los compuestos: trans-Z-alfabisaboleno y el Safrol, a los que se les realizaron pruebas del efecto anti parasitario que presentaron un CI50 de 50.0 µg/mL y 0.0 µg/mL, respectivamente. Además, se discute la importancia de estos nuevos hallazgos. El compuesto mayoritario presente en los aceites esenciales (Safrol) no es el componente que presentó la actividad. Es importante realizar estudios sobre su proyección en el tratamiento de la leishmaniasis.

Abstract The leishmaniosis disease incidence is high in tropical regions, and its current treatment has shown severe secondary effects. Considering this problem, many studies have focused on plants, looking for chemical components that have anti-leishmanial activity, and are free of adverse effects for human beings. The purpose of this work was to find a chemical component with this kind of activity in Piper auritum. In a phytochemical screening of this plant, we found some cumarins, terpens, triterpens and reducing sugars; and later, we identified the components trans-Z-α-bisabolene epoxide and Safrol. The first component presented a CI50 of 50.0 µg/mL of anti-Leishmania activity. The Safrol, which is the major component of the essential oils of this plant, did not show antiparasitic activity. These results are discussed considering treatment of leishmaniasis. Rev. Biol. Trop. 66(2): 826-835. Epub 2018 June 01.

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The direct in vitro fungitoxicity and metabolism of safrole and dillapiole (isolated from Piper auritum and Piper holtonii, respectively) by Botryodiplodia theobromae and Colletotrichum acutatum were investigated. Higher values of mycelial growth inhibition for both fungi were obtained for dillapiole, as compared with safrole. B. theobromae was able to metabolize both compounds to their respective vicinal diols, reaching 65 percent relative abundance during the biotransformation of dillapiole; while C. acutatum only transformed safrole to various metabolites with relative abundances under 5 percent. According to the low antifungal activity of the major metabolic products (< 5 percent for vicinal diols), a detoxification process was implied. Studies on the influence of some substituents in the aromatic ring of safrole and dillapiole on the antifungal activity against B. theobromae were also carried out. As result, the safrole nitrated derivative, 6-nitrosafrole, showed a fungitoxicity level similar to that displayed by the commercial fungicide Carbendazim® under the conditions used. In light of this, safrole and dillapiole could be suggested as feasible structural templates for developing new antifungal agents.

Se investigó la fungitoxicidad directa in vitro y el metabolismo de safrol y dilapiol (obtenidos desde Piper auritum and Piper holtonii, respectivamente) por Botryodiplodia theobromae y Colletotrichum acutatum. Los valores mayores de inhibición del crecimiento micelial de ambos hongos se obtuvieron para dilapiol, en comparación con safrol. B. theobromae metabolizó ambos compuestos a sus respectivos dioles vecinales, alcanzando abundancias relativas del 65 por ciento durante la biotransformación del dilapiol; mientras que C. acutatum solo transformó safrol en varios metabolitos con abundancias relativas menores al 5 por ciento. De acuerdo con la baja actividad antifúngica de los productos metabólicos mayoritarios (< 5 por ciento para los dioles vecinales), se sugiere un proceso de desintoxicación. Adicionalmente, se evaluó la influencia de algunos sustituyentes en el anillo aromático de safrol y dilapiol sobre la actividad antifúngica contra B. theobromae. Como resultado, el derivado nitrado del safrol, el 6–nitro safrol, presentó un nivel de fungitoxicidad similar al exhibido por el fungicida comercial Carbendazim® bajo las condiciones usadas. A la luz de lo anterior, safrol y dilapiol podrían ser sugeridos como plantillas estructurales adecuadas para el desarrollo de nuevos agentes antifúngicos.

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A guanine-rich DNA oligonucleotide complexed with hemin was used to catalyze controlled oxygen transfer reactions to different sulfides for sulfoxide preparation in the presence of H2O2. Comparable activities were obtained when using fully modified L-DNA. In addition, oligonucleotide immobilization led to an active catalyst which could be successfully recovered and reused without loss of activity.

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Long pepper (Piper hispidinervum) is an Amazonian species of commercial interest due to the production of safrole. Drying long pepper biomass to extract safrole is a time consuming and costly process that can also result in the contamination of the material by microorganisms. The objective of this study was to analyze the yield of essential oil and safrole content of fresh and dried biomass of long pepper accessions maintained in the Active Germoplasm Bank of Embrapa Acre, in the state of Acre, Brazil, aiming at selecting genotypes with best performance on fresh biomass to recommend to the breeding program of the species. Yield of essential oil and safrole content were assessed in 15 long pepper accessions. The essential oil extraction was performed by hydrodistillation and analyzed by gas chromatography. A joint analysis of experiments was performed and the means of essential oil yield and safrole content for each biomass were compared by Student's t-test. There was variability in the essential oil yield and safrole content. There was no difference between the types of biomass for oil yield; however to the safrole content there was difference. Populations 9, 10, 12 and 15 had values of oil yield between 4.1 and 5.3%, and safrole content between 87.2 and 94.3%. The drying process does not interfere in oil productivity. These populations have potential for selection to the long pepper breeding program using oil extraction in the fresh biomass.

A pimenta longa (Piper hispidinervum) é uma espécie amazônica de interesse comercial devido à produção de safrol. A secagem da biomassa para extração do óleo essencial demanda tempo e acarreta custos, podendo também resultar em contaminação do material por microorganismos. O objetivo deste estudo foi analisar o rendimento de óleo essencial e teor de safrol da biomassa verde e seca de acessos de pimenta longa mantida no Banco Ativo de Germoplasma da Embrapa Acre a fim de selecionar genótipos com melhor desempenho em biomassa verde para recomendação ao programa de melhoramento genético da espécie. O rendimento do óleo essencial e o teor de safrol foram avaliados em 15 acessos de pimenta longa. Foi realizada uma análise conjunta de experimentos e as médias do rendimento do óleo essencial e do teor de safrol para cada população foram comparadas pelo teste t de Student. Houve variabilidade do rendimento de óleo essencial e do teor de safrol. Não houve diferença entre os tipos de biomassa para o rendimento do óleo, já para o teor de safrol houve diferença. As populações 9, 10, 12 e 15 mostraram valores de rendimento de óleo entre 4,1 e 5,3%, e teor de safrol entre 87,2 e 94,3%. O processo de secagem não interfere na produtividade de óleo. Estas populações têm potencial para seleção para o programa de melhoramento genético de pimenta longa por meio da extração de óleo essencial da biomassa verde.

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Long pepper (Piper hispidinervum) is an Amazonian species of commercial interest due to the production of safrole. Drying long pepper biomass to extract safrole is a time consuming and costly process that can also result in the contamination of the material by microorganisms. The objective of this study was to analyze the yield of essential oil and safrole content of fresh and dried biomass of long pepper accessions maintained in the Active Germoplasm Bank of Embrapa Acre, in the state of Acre, Brazil, aiming at selecting genotypes with best performance on fresh biomass to recommend to the breeding program of the species. Yield of essential oil and safrole content were assessed in 15 long pepper accessions. The essential oil extraction was performed by hydrodistillation and analyzed by gas chromatography. A joint analysis of experiments was performed and the means of essential oil yield and safrole content for each biomass were compared by Student's t-test. There was variability in the essential oil yield and safrole content. There was no difference between the types of biomass for oil yield; however to the safrole content there was difference. Populations 9, 10, 12 and 15 had values of oil yield between 4.1 and 5.3%, and safrole content between 87.2 and 94.3%. The drying process does not interfere in oil productivity. These populations have potential for selection to the long pepper breeding program using oil extraction in the fresh biomass.(AU)

A pimenta longa (Piper hispidinervum) é uma espécie amazônica de interesse comercial devido à produção de safrol. A secagem da biomassa para extração do óleo essencial demanda tempo e acarreta custos, podendo também resultar em contaminação do material por microorganismos. O objetivo deste estudo foi analisar o rendimento de óleo essencial e teor de safrol da biomassa verde e seca de acessos de pimenta longa mantida no Banco Ativo de Germoplasma da Embrapa Acre a fim de selecionar genótipos com melhor desempenho em biomassa verde para recomendação ao programa de melhoramento genético da espécie. O rendimento do óleo essencial e o teor de safrol foram avaliados em 15 acessos de pimenta longa. Foi realizada uma análise conjunta de experimentos e as médias do rendimento do óleo essencial e do teor de safrol para cada população foram comparadas pelo teste t de Student. Houve variabilidade do rendimento de óleo essencial e do teor de safrol. Não houve diferença entre os tipos de biomassa para o rendimento do óleo, já para o teor de safrol houve diferença. As populações 9, 10, 12 e 15 mostraram valores de rendimento de óleo entre 4,1 e 5,3%, e teor de safrol entre 87,2 e 94,3%. O processo de secagem não interfere na produtividade de óleo. Estas populações têm potencial para seleção para o programa de melhoramento genético de pimenta longa por meio da extração de óleo essencial da biomassa verde.(AU)

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Stored grain insects have shown resistance to synthetic insecticides, fact that has promoted the use of vegetable species for integrated pest management. Piper auritum and P. multiplinervium are two plants from the Piperaceae family present in the department of Chocó, Colombia, one of the most important hot spots of biodiversity in the world. This study was conducted to determine the repellent activity and toxicity of essential oils (EOs) isolated from these plants against Tribolium castaneum, using the area preference and contact toxicity methods, respectively. P. auritum EO presented greater repellency than P. multiplinervium, the first showed 100 percent lethality at minimum tested exposure period (24 h) whereas the second reached 16 percent at 72 h. EOs were analyzed by gas chromatography-mass spectrometry. P. auritum major components were safrole (93.2 percent) and miristicine (4.3 percent), whereas for P. multiplinervium were beta-elemene (9.0 percent), trans-beta-caryophyllene (5.3 percent) and caryophyllene oxide (4.1 percent). It is speculated that the repellent effect of P. auritum may be related to its safrole content, a known repellent. These results evidenced Piper species could be used for development of repellents against T. castaneum.

Los insectos de los granos almacenados han mostrado resistencia a los insecticidas sintéticos, hecho que ha promovido el uso de especies vegetales para el manejo integrado de plagas. Piper auritum y P. multiplinervium son dos plantas de la familia Piperaceae presentes en el departamento del Chocó, Colombia, uno de los puntos de biodiversidad más importantes del mundo. En este estudio fue determinada la actividad repelente y toxicidad de los aceites esenciales (AE) aislados de estas plantas contra Tribolium castaneum, utilizando el método de área de preferencia y toxicidad por contacto, respectivamente. El AE de P. auritum presentó mayor repelencia que el de P. multiplinervium, el primero mostró 100 percent de letalidad al menor tiempo de exposición (24 h), mientras que el segundo alcanzó el 16 percent a las 72 h. Los AEs fueron analizados por cromatografía de gases-espectrometría de masas. Los componentes principales de P. auritum fueron safrol (93.2 percent) y miristicina (4.3 percent), mientras que para P. multiplinervium fueron beta-elemene (9.0 percent), trans-beta-cariofileno (5.3 percent) y óxido de cariofileno (4.1 percent). Se cree que el efecto repelente de P. auritum puede estar relacionado con su contenido de safrol, un repelente conocido. Estos resultados evidencian que las especies de Piper podrían ser utilizadas para el desarrollo de repelentes contra T. castaneum.

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