ABSTRACT Essential oils used as bioherbicides are a promising alternative in agriculture. This study aimed to assess the phytotoxic potential of Piper marginatum essential oil through an in vitro study with detached and post-emergence leaves of three commercial species (lettuce, pepper, and tomato) and a weed (Spermacoce verticillata). The experiments were conducted in a randomized design with six treatments that consisted of four concentrations of essential oil (0.001, 0.01, 0.1, and 1% [v/v]) and two control treatments (distilled water, and 1% polysorbate 80 in distilled water). The P. marginatum essential oil had a phytotoxic effect on the leaves of the experimental species. The highest essential oil concentration resulted in greater toxicity effects on tomato, lettuce, and pepper leaves. The 0.1% essential oil concentration completely destroyed the S. verticillata leaves. Seven days after application, the P. marginatum essential oil did not show adverse effects on plant growth in the post-emergence phase. It is recommended to investigate its possible phytotoxic activity in other phases of plant development to understand its mode of action and potential as an alternative to developing bioproducts for weed control. agriculture postemergence post emergence lettuce (lettuce tomato Spermacoce verticillata. . verticillata) 0.001, 0001 0 001 (0.001 01 0.01 1 0.1 v/v vv v [v/v] water 8 water. water) P S application phase 0.001 000 00 (0.00 0.0 0. [v/v 0.00 (0.0 (0. (0 (

RESUMO Óleos essenciais usados como bioherbicidas são uma alternativa promissora na agricultura. O objetivo deste trabalho foi avaliar o potencial fitotóxico do óleo essencial de Piper marginatum, através de estudo in vitro com folhas destacadas e em pós-emergência de três espécies comerciais (alface, pimentão e tomate) e uma planta daninha (Spermacoce verticillata). Os experimentos foram conduzidos em delineamento casualizado com seis tratamentos que consistiram em quatro concentrações de óleo essencial (0,001; 0,01; 0,1 e 1% [v/v]), e dois tratamentos controle (água destilada, e 1% de polissorbato 80 em água destilada). O óleo essencial de P. marginatum apresentou efeito fitotóxico sobre as folhas das espécies experimentais. A maior concentração de óleo essencial resultou em maiores efeitos de toxicidade nas folhas de tomate, alface e pimentão. A concentração de 0,1% de óleo essencial foi suficiente para destruir completamente as folhas de S. verticillata. Sete dias após a aplicação, o óleo essencial de P. marginatum não evidenciou efeitos adversos no crescimento das plantas na fase pós-emergencial. Recomenda-se investigar sua possível atividade fitotóxica em outras fases do desenvolvimento vegetal, para entender o seu modo de ação e potencial como alternativa no desenvolvimento de bioprodutos para controle de plantas daninhas. agricultura pósemergência pós emergência alface, (alface tomate Spermacoce verticillata . verticillata) 0,001 0001 0 001 (0,001 0,01 01 1 0, v/v, vv v/v , v [v/v]) destilada 8 destilada. destilada) P experimentais S aplicação pósemergencial. pósemergencial emergencial. emergencial pós-emergencial Recomendase Recomenda se vegetal daninhas 0,00 000 00 (0,00 0,0 [v/v] (0,0 [v/v (0, (0 (

RESUMEN Los aceites esenciales sirven como un sustituto viable para la utilización de antimicrobianos convencionales. En la actualidad, la distribución mundial de cepas de Streptococcuspneumoniae son resistentes a la penicilina. Esta bacteria en particular posee la capacidad de causar daño a los seres humanos. Se evalúa la eficacia antimicrobiana del timol, un compuesto activo que se encuentra en el aceite de tomillo. Se examinaron un total de 30 cepas distintas de Streptococcuspneumoniae. La metodología empleada en este estudio fue la técnica de microdilución en caldo. Los resultados revelaran que la mayoría de las cepas mostraron resultados similares tanto en las pruebas de concentración inhibitoria mínima como en las de concentración bactericida mínima. Estas alteraciones permitieron a los investigadores detectar y establecer de manera efectiva la actividad antimicrobiana del timol como una posible opción de tratamiento alternativo.

ABSTRACT Essential oils serve as a viable substitute for the use of conventional antimicrobials. Currently, the worldwide distribution of strains of Streptococcus pneumoniae are resistant to penicillin. This particular bacterium has the ability to cause harm to humans. The antimicrobial efficacy of thymol, an active compound found in thyme oil, is evaluated. A total of 30 different strains of Streptococcus pneumoniae were examined. The methodology used in this study was the broth microdilution technique. The results reveal that most of the strains showed similar results in both the minimum inhibitory concentration and minimum bactericidal concentration tests. These alterations allowed the researchers to effectively detect and establish the antimicrobial activity of thymol as a possible alternative treatment option.

ABSTRACT Piper marginatum and Piper tuberculatum are species used for their insecticidal properties by local indigenous people in eastern Ecuador. This study aimed to determine the acaricidal and larvicidal activity of the essential oil of these species. The essential oils were obtained by hydrodistillation. The acaricidal activity was evaluated with the contact toxicity method against larvae of the tick Rhipicephalus microplus. Larvicidal activity was evaluated against Aedes aegypti mosquito larvae following WHO recommended guidelines. The essential oils of P. marginatum and P. tuberculatum showed an acaricidal potential with LC50 of 0.90 and 0.73 µL mL-1,respectively. In addition, excellent larvicidal activity was obtained with LC50 of 11.87 µL mL-1 (P. marginatum) and 8.42 µL mL-1 (P. tuberculatum) at 48 hours of evaluation. This is the first report of the acaricidal activity of P. marginatum and P. tuberculatum essential oils against R. microplus tick larvae. The results indicate that essential oils could serve as a natural alternative for controlling these pests, with ethnobotanical applications as a lice and tick repellent.

Piper marginatum y Piper tuberculatum son especies utilizadas por sus propiedades insecticidas por indígenas locales del este de Ecuador. Este estudio tuvo como objetivo determinar la actividad acaricida y larvicida del aceite esencial de estas especies. Los aceites esenciales se obtuvieron por hidrodestilación. La actividad acaricida se evaluó con el método de toxicidad por contacto frente a larvas de la garrapata Rhipicephalus microplus. Se evaluó la actividad larvicida contra larvas del mosquito Aedes aegypti siguiendo los lineamientos recomendados por la OMS. Los aceites esenciales de P. marginatum y P. tuberculatum mostraron un potencial acaricida con CL50 de 0.90 y 0.73 µL mL-1,respectivamente. Además, se obtuvo una excelente actividad larvicida con CL50 de 11.87 µL mL-1 (P. marginatum) y 8.42 µL mL-1 (P. tuberculatum) a las 48 horas de evaluación. Este es el primer reporte de la actividad acaricida de los aceites esenciales de P. marginatum y P. tuberculatum frente a las larvas de la garrapata R. microplus. Los resultados indican que los aceites esenciales podrían servir como una alternativa natural para el control de estas plagas, con aplicaciones etnobotánicas como repelente de piojos y garrapatas.

Abstract Citrus production in Colombia is divided into six productive centers, with a total production of 1,450 thousand tons in 2021. The greater entrepreneurial activity stands out in the West and a lower level in the South, which generates 230 thousand tons per year of citrus waste, posing challenges in terms of pollution and wet/semi-solid waste management. This study evaluates the industrial potential of these waste products for strengthening the national citrus industry, considering three aspects: raw materials availability, technological opportunities, and market opportunities. The results indicate that Colombia has a robust citrus production, with an emphasis on oranges, mandarins, and lemons, and significant potential in the industrialization of the peel, which constitutes between 40% and 60% of the total fruit. To industrialization were identified six key research areas of citrus waste in terms of technological opportunities. Regarding market opportunities, there is observed growth both nationally and internationally in products derived from citrus waste, including essential oils, terpenes, dietary fiber, pectin, citric acid, and biofuels. Colombia is considered a country with great potential for the industrialization of citrus waste, supported by its abundant raw materials, promising technological opportunities, and a growing market. However, improvements in infrastructure, investment in research and development, and the promotion of entrepreneurial culture in the citrus sector are needed to fully capitalize on this opportunity.

Resumen La producción de cítricos en Colombia se divide en seis núcleos productivos con una producción en 2021, de 1450 mil toneladas. Se destaca mayor empresarización en el Occidente y menor nivel en el Sur, lo que genera 230 mil toneladas por año de residuos cítricos, planteando desafíos de contaminación y gestión de desechos húmedos/semi-sólidos. El presente estudio evalúa el potencial industrial de estos residuos para el fortalecimiento de la industria citrícola nacional, considerando tres aspectos: disponibilidad de materia prima, oportunidades tecnológicas y oportunidades de mercado. Los resultados indican que Colombia tiene una sólida producción de cítricos, con énfasis en naranjas, mandarinas y limones, y un potencial significativo en la industrialización de la cáscara, que constituye entre el 40% y el 60% del total de la fruta. Se identifican seis áreas clave de investigación para la industrialización de residuos cítricos en términos de oportunidades tecnológicas. En cuanto a las oportunidades de mercado, se observa un crecimiento tanto a nivel nacional como internacional en productos derivados de residuos cítricos, que incluyen aceites esenciales, terpenos, fibra dietética, pectina, ácido cítrico y biocombustibles. Colombia se considera un país con un gran potencial para la industrialización de residuos cítricos, respaldado por su abundante materia prima, prometedoras oportunidades tecnológicas y un mercado en crecimiento. Sin embargo, se requiere mejorar la infraestructura, invertir en investigación y desarrollo, y promover la cultura empresarial en el sector citrícola para aprovechar al máximo esta oportunidad.

ABSTRACT The ancestral use of essential oils, obtained from various parts of plants, encompasses a wide range of purposes, including medicinal, flavoring, preserving, and aromatic uses. This research focused on conducting a comprehensive literature review on the use of essential oils in the sausage industry. A descriptive, inductive, and analytical approach was adopted, drawing on a variety of sources such as books, journals, technical regulations, theses, and scientific articles. The results of this study revealed that, out of the 92 technical documents (articles and theses) initially selected, 24 were excluded due to their age, leaving a total of 68 articles for the preparation of the technical document. Additionally, 21 documents were identified that provided specific information on the components and effects of essential oils in sausage manufacturing. In conclusion, it is highlighted that essential oils extracted from various plants, such as clove, rosemary, oregano, thyme, among others, have demonstrated their ability to prolong the shelf life of sausages by inhibiting the growth of pathogenic microorganisms and preventing lipid oxidation. Furthermore, it was observed that the application of these essential oils not only contributes to the preservation of meat products but also improves their organoleptic properties by imparting distinctive flavors and aromas.

RESUMEN El empleo ancestral de aceites esenciales, obtenidos de diversas partes de las plantas, abarca una amplia gama de propósitos, incluyendo usos medicinales, condimentarios, conservantes y aromatizantes. Esta investigación se centró en realizar una revisión bibliográfica sobre el uso de aceites esenciales en la industria de embutidos. Se adoptó un enfoque descriptivo, inductivo y analítico, recurriendo a una diversidad de fuentes como libros, revistas, normativas técnicas, tesis y artículos científicos. Los resultados de este estudio revelaron que, de los 92 documentos técnicos (artículos y tesis) inicialmente seleccionados, 24 fueron excluidos debido a su antigüedad, dejando un total de 68 artículos para la elaboración del documento técnico. Además, se identificaron 21 documentos que proporcionaron información específica sobre los componentes y efectos de los aceites esenciales en la fabricación de embutidos. Como conclusión, se destaca que los aceites esenciales extraídos de diversas plantas, como clavo, romero, orégano, tomillo, entre otros, han demostrado su capacidad para prolongar la vida útil de los embutidos al inhibir el crecimiento de microorganismos patógenos y prevenir la oxidación lipídica. Además, se observó que la aplicación de estos aceites esenciales no solo contribuye a la conservación de los productos cárnicos, sino que también mejora sus propiedades organolépticas al conferirles sabores y aromas distintivos.

Abstract The objective was to evaluate the increasing use of garlic, sesame, and cinnamon oil in the production of CH4 in 60 d in vitro regrowth of Koronivia grass. The addition of 0, 2.5, 5.0, 5.0, 7.5, and 10 % garlic, cinnamon, or sesame oil was evaluated in an in vitro fermentation using a 60-d regrowth of Koronivia grass as substrate. The variables evaluated were cumulative CH4 production at 12, 24, 36, 36, 48, and 72 h; dry matter degradation (DMD), and CH4 production kinetics estimators (A= CH4 production potential, b= CH4 production rate constant, and k= lag time). The CH4 production and the DMD were analyzed with a completely randomized experimental design and orthogonal contrast. The estimators were subjected to a descriptive analysis. An increase of garlic oil and cinnamon linearly reduced CH4 production at 12, 24, 36, 48, and 72 h. The DMD decreased linearly with the use of any of the three oils (P<0.05). The highest value of A was obtained with 2.5 % garlic oil, and the highest value of k and b, with 10 % cinnamon oil. In conclusion, the use of garlic and cinnamon oils resulted in a linear decrease of Koronivia grass CH4 and Koronivia grass DMD under in vitro conditions.

Resumen El objetivo fue evaluar el uso creciente de aceite de ajo, ajonjolí y canela en la producción de CH4 in vitro de pasto llanero con 60 días de rebrote. Se evaluó la adición de 0, 2.5, 5.0, 7.5 y 10 % de aceite de ajo, canela o ajonjolí en una fermentación in vitro usando como sustrato pasto llanero con 60 días de rebrote. Las variables evaluadas fueron producción acumulada de CH4 a las 12, 24, 36, 48 y 72 h, degradación de materia seca (DMS) y los estimadores de cinética de producción de CH4 (A= potencial de producción de CH4, b= tasa constante de producción de CH4 y k= tiempo lag). La producción de CH4 y DMS se analizaron con un diseño experimental completamente al azar y contraste ortogonal. Los estimadores fueron un análisis descriptivo. El aumento de aceite de ajo y canela redujo linealmente la producción de CH4 a las 12, 24, 36, 48 y 72 h. La DMS disminuyó linealmente con cualquiera de los tres aceites (P<0.05). El mayor valor de A fue con 2.5 % de aceite de ajo, el mayor valor de k y b fue con 10 % de aceite de canela. En conclusión, el uso de aceites de ajo y canela mostraron una disminución lineal de la producción de CH4 y DMS de pasto llanero en condiciones in vitro.

Abstract Citral is a secondary metabolite found in the composition of many essential oils from plants, such as the essential oil of Cymbopogon citratus (DC.) Stapf, in which it is the major constituent. Citral has been demonstrated to possess several biological activities, among them herbicidal activity, so it has a high potential for the development of natural herbicides. In this work, the phytotoxic potential of citral was studied on two weeds, Avena fatua L. (monocotyledonous) and Chenopodium album L. (dicotyledonous). The tests were carried out under greenhouse conditions at the Universitat Politècnica de València. Citral was tested at different concentrations applied by spraying in post-emergence when the plants had 2-3 leaves in the case of A. fatua and 4-6 leaves in the case of C. album. The results showed high efficacy of citral as herbicide under greenhouse conditions. Trials on other species and under field conditions would be necessary to verify its herbicidal potential under real conditions, but it was shown to be a good candidate for bioherbicide formulations.

Resumen El citral es un metabolito secundario que se encuentra en la composición de muchos aceites esenciales de plantas, como por ejemplo en el aceite esencial de Cymbopogon citratus (DC.) Stapf, en el que es el componente mayoritario. Se trata de una molécula con diferentes propiedades biológicas, entre ellas, se ha demostrado su actividad herbicida, lo que le confiere un elevado potencial como base para el desarrollo de herbicidas naturales. En este trabajo, se ha estudiado el potencial fitotóxico del citral sobre dos arvenses, Avena fatua L. (moconotiledónea) y Chenopodium album L. (dicotiledónea). Los ensayos se llevaron a cabo en condiciones de invernadero en la Universitat Politècnica de València. Se probó el citral a diferentes concentraciones aplicado mediante pulverización en post emergencia sobre las plantas arvenses cuando tenían 2-3 hojas en el caso de A. fatua y 4-6 hojas para C. album. Los resultados mostraron una elevada efectividad del citral como herbicida en condiciones de invernadero. Sería necesario realizar ensayos sobre otras especies y en condiciones de campo, para verificar su potencial herbicida en condiciones reales, pero se demostró que puede ser un buen candidato para la formulación de bioherbicidas.

Abstract Synthetic herbicides have been the most widely used tool for weed control since their discovery and development in the mid-20th century. However, their continued use has led to the emergence of resistant weed biotypes, reducing their efficacy. They also provoked environmental problems, affecting non-target species, and causing crop stress. It is therefore necessary to look for new herbicides that could be effective in controlling weeds while also being environmentally friendly. The essential oils of some plants have compounds with phytotoxic properties, which can inhibit the germination and growth of weeds. Carvacrol is a monoterpene phenol found mainly in the essential oils of plants of the Lamiaceae family, with proven herbicidal activity. The aim of the present work was to obtain a dose-response curve of carvacrol on Lolium rigidum (monocotyledonous weed model) and Sonchus oleraceus (dicotyledonous weed model). The tests were carried out under greenhouse conditions, applying different doses of carvacrol on the weeds studied to obtain the dose-response curves. To assess the herbicidal activity of carvacrol, its efficacy on weeds were determined. S. oleraceus was more sensitive to carvacrol than L. rigidum. The dose-response curves obtained will be used in the future as a reference for field trials and for the study of synergistic interactions of carvacrol with other compounds.

Resumen Los herbicidas sintéticos han sido la herramienta más utilizada para el control de las plantas arvenses desde su descubrimiento y desarrollo a mediados del siglo XX. Sin embargo, su uso continuado ha llevado a la aparición de biotipos de arvenses resistentes, disminuyendo su eficacia. Además, han causado problemas medioambientales, afectan a especies no diana, y pueden producir fitotoxicidad en los cultivos. Por ello, es necesario buscar nuevas materias herbicidas que sean efectivas en el control de las arvenses pero respetuosas con el medio ambiente. Los aceites esenciales de algunas plantas poseen compuestos con propiedades fitotóxicas, que pueden inhibir la germinación y el crecimiento de las arvenses. El carvacrol es un fenol monoterpénico que se encuentra principalmente en los aceites esenciales de las plantas de la familia Lamiaceae, con demostrada actividad herbicida. El objetivo del presente trabajo fue obtener una curva dosis-respuesta del carvacrol sobre las especies Lolium rigidum (modelo de arvense monocotiledónea) y Sonchus oleraceus (modelo de arvense dicotiledónea). Los ensayos se realizaron en invernadero, aplicando distintas dosis de carvacrol sobre las arvenses estudiadas a fin de obtener la curva dosis-respuesta de cada una de ellas. Para evaluar la actividad herbicida del carvacrol se determinó su eficacia. S. oleraceus fue más sensible al carvacrol que L. rigidum. La obtención de estas curvas dosis-respuesta permitirá en el futuro utilizarlas como referencia para realizar ensayos en condiciones de campo y para el estudio de interacciones sinérgicas del carvacrol con otros compuestos.

Abstract Due to its allelopathic capability, the investigation of essential oils (EO) as sustainable alternatives for weed control has gained considerable interest in the last years. In this study, we investigated the phytotoxic capacity of the essential oil extracted from Carlina acaulis L. (Apiaceae) on the weed Bidens pilosa L. This essential oil, mainly composed of carlina oxide (98%), has demonstrated remarkable phytotoxic effects on the metabolism of Bidens pilosa. These effects include leaf necrosis, a reduction in relative water content and total leaf area, and an increase in the dry weight/fresh weight ratio, indicating possible alteration in the plant's water status. After EO short-exposition, analysis of the photosynthetic system revealed a significant decrease in the photochemical efficiency of photosystem II (Φ II) and the maximum photochemical efficiency of photosystem II (F v /F m ). In contrast, the energy dissipated as heat (Φ NPQ) increased significantly. Damage to photosystem II was accompanied by a decrease in manganese and calcium concentrations, suggesting an alteration in the Mn4Ca cluster of photosystem II. Metabolomics analysis revealed a general decrease in sugar content and an accumulation of isoleucine and valine, commonly associated with osmotic stress situations. Our results indicate that the EO of C. acaulis is a promising natural product with strong phytotoxic potential against Bidens pilosa, and the exploration of its effects on other weeds is suggested.

Resumen Gracias a su capacidad alelopática, la investigación de aceites esenciales (AE) como alternativas sostenibles para el control de malas hierbas ha despertado un considerable interés a lo largo de los últimos años. En este estudio, se ha evaluado la capacidad fitotóxica del AE extraído de Carlina acaulis L. (Apiaceae) en la mala hierba Bidens pilosa L. Este aceite, principalmente compuesto de óxido de carlina (98%), ha exhibido notables efectos fitotóxicos en el metabolismo de Bidens pilosa. Estos efectos incluyen necrosis en las hojas, reducción en el contenido relativo de agua y área foliar total, y un aumento en la relación peso seco/peso fresco, indicando una posible alteración en el estado hídrico de la planta. El análisis del sistema fotosintético reveló una significativa disminución en la eficiencia fotoquímica del fotosistema II (Φ II) y en la eficiencia cuántica máxima del fotosistema II (F v /F m ) tras la aplicación del AE. En contraste, la energía disipada en forma de calor (Φ NPQ) aumentó significativamente. El daño al fotosistema II coincidió con una disminución en las concentraciones de manganeso y calcio, sugiriendo una alteración en el clúster Mn4Ca del fotosistema II. El análisis metabolómico reveló acumulación de isoleucina y valina, asociadas comúnmente con estrés osmótico, y una disminución general en el contenido de azúcares. Nuestros resultados indican que el AE de C. acaulis es un producto natural prometedor con un fuerte potencial fitotóxico contra Bidens pilosa, y se sugiere la exploración de sus efectos en otras malas hierbas.

Abstract Under the IWM strategy for the post-herbicide era, allelopathy may play a relevant role, as many plants produce a variety of allelochemicals with different structures and new modes of action capable of inhibiting weed germination and growth. Inspired by green manuring with cover crops, using allelopathic biomass from weed species, invasive plants, forest plantation residues, and other abundant wild plants has additional advantages over green manures grown in situ or other alternatives such as applying extracts or essential oils. In addition to the multiple ecosystem services provided by green manures, the use of allelopathic biomass offers new opportunities for research and practice of holistic, integrated weed management because (i) it would alleviate the resource investment to produce cover crops and (ii) it provides a new use of agroforestry residues and a sink for biomass of invasives. We compiled examples of allelopathic species whose biomass used as a soil amendment has demonstrated significant weed control, revisiting the complex allelopathic processes underlying the efficacy of cover crops and allelopathic biomass used as green manures and amendments. This communication to the XIX SEMh Congress complements a review published in the journal Agronomy with a summary of the advantages and possible disadvantages of following this plant-based strategy in the transition to holistic IWM systems.

Resumen Bajo la estrategia de IWM en la era post-herbicida, la alelopatía puede jugar un papel relevante, ya que muchas plantas producen una variedad de aleloquímicos con diferentes estructuras y nuevos modos de acción, capaces de inhibir la germinación y el crecimiento de malas hierbas. Inspirándonos en la práctica del abonado en verde con cultivos de cobertura, el uso de biomasa alelopática procedente de especies arvenses, plantas invasoras, residuos de plantaciones forestales, y otras plantas silvestres abundantes tiene ventajas adicionales sobre los abonos verdes cultivados in situ, u otras alternativas como la aplicación de extractos o aceites esenciales. Además de los múltiples servicios ecosistémicos proporcionados por los abonos verdes, el uso de biomasa alelopática ofrece nuevas oportunidades para la investigación y la práctica de la gestión holística integrada de malas hierbas porque (i) aliviaría la inversión de recursos para producir cultivos de cobertura, y (ii) proporciona un nuevo uso de residuos agroforestales y un sumidero para la biomasa de invasoras. Hemos recopilado ejemplos de especies alelopáticas cuya biomasa utilizada como enmienda del suelo ha demostrado un control significativo de malas hierbas, revisando los complejos procesos alelopáticos que subyacen a la eficacia de los cultivos de cobertura y la biomasa alelopática utilizados como abonos verdes y enmiendas del suelo. Esta comunicación al XIX Congreso de la SEMh complementa una revisión publicada en la revista Agronomy con un resumen de las ventajas y posibles inconvenientes del seguimiento de esta estrategia basada en plantas, en la transición hacia sistemas holísticos de IWM.

Abstract The need to obtain new generation herbicides based on allelochemicals has prompted in recent years the use of more sustainable natural products, such as plant essential oils. This study evaluated the impact of plant phenological stage on the chemical composition and bioherbicidal potential of Cistus ladanifer L. essential oil. The essential oil was extracted by hydrodistillation and analysed by gas chromatography coupled to mass spectrometry (GC-MS). The oxygenated sesquiterpenes were the most representative group of the essential oil and the chemical composition varied according to the plant phenological stage. The bioherbicidal effect was tested in vitro on the weed Echinochloa crus-galli and two of its respective associated crops (rice and tomato). We tested three increasing doses of essential oil (0.022; 0.044 and 0.088 μl/mL of headspace in the Petri dish) and a control with distilled water. Five replicates per phenological stage, dose and species were prepared, with 10 seeds in each replicate. The Aligned Ranks Anova analysis showed a significant effect for the three factors analysed (phenological stage, dose and species). However, the dose-dependent phytotoxic effect was significantly higher on Echinochloa crus-galli compared to rice and tomato at medium and low doses (0.022 and 0.044 µl/ml). Furthermore, the essential oil extracted in October, with a higher percentage of hydrocarbon monoterpenes, showed a significantly higher phytotoxic effect than that obtained in August. Therefore, these results show the high potential of C. ladanifer essential oil for use as a bioherbicide in agriculture.

Resumen La necesidad de obtener herbicidas de nueva generación basados en aleloquímicos ha impulsado en los últimos años el uso de productos naturales más sostenibles, como pueden ser los aceites esenciales de plantas. El estudio evaluó el impacto del estado fenológico de la planta sobre la composición química y el potencial bioherbicida del aceite esencial de Cistus ladanifer L. El aceite esencial fue extraído por hidrodestilación y analizado por cromatografía de gases acoplada a espectrometría de masas (GC-MS). La composición química varió en función del estado fenológico de la planta, pero el grupo más representativo de compuestos del aceite esencial fueron los sesquiterpenos oxigenados. El efecto herbicida se testó in vitro sobre la mala hierba Echinochloa crus-galli y en dos de sus respectivos cultivos asociados (arroz y tomate). Se ensayaron tres dosis crecientes de aceite esencial (0,022; 0,044 y 0,088 μl/mL de espacio libre en la placa Petri) y un control con agua destilada. Se prepararon 5 repeticiones por estado fenológico, dosis y especie, con 10 semillas en cada repetición. El análisis Anova de Rangos Alineados mostró un efecto significativo para los tres factores analizados (estado fenológico, dosis y especie). Sin embargo, este efecto fitotóxico dependiente de la dosis fue significativamente mayor sobre Echinochloa crus-galli en comparación con arroz y tomate a dosis medias y bajas (0,022 y 0,044 µl/ml). Además, el aceite esencial obtenido en octubre, con un mayor porcentaje de monoterpenos hidrocarbonados, mostró un efecto fitotóxico significativamente mayor que aquel obtenido en agosto. Por tanto, estos resultados muestran el elevado potencial del aceite esencial de C. ladanifer para su empleo como bioherbicida en agricultura.

Abstract Previous investigations suggested the orange essential oil as antimicrobial and natural antioxidant; however, the high volatility and sensibility due to extern factors are imitating its applications. Thus, the encapsulation is an ideal alternative of protection for essentials oils and the molecular inclusion has greater advantages compared to others, but the drying method and temperature can influence its characteristics and stability. Therefore, the orange essential oil was microencapsulated into beta-cyclodextrin (β-CD), and was evaluated the effect of drying by stove, lyophilization and atomization (160, 180 and 200 °C) on humidity, water activity, encapsulation efficiency, yield, and stability (82% relative humidity for 36 days). The microparticles were analyzed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The best drying method was lyophilization achieved an encapsulation efficiency of 97,35%, humidity 1,76%, water activity 0,54, and low hygroscopicity 0,20%. The results by FTIR found the formation and loss of some bonds between orange essential oil and beta-cyclodextrin, probably by effect of temperature. The lyophilized microparticles presented best stability with final efficiency of 52,53% with low humidity and water activity. This study makes it possible to establish the best drying method in cases of molecular inclusion, which may be useful in future applications when developing products.

Resumen Previas investigaciones sugieren al aceite esencial de naranja como un antimicrobiano y antioxidante natural; sin embargo, la alta volatilidad y sensibilidad a factores externos limita sus aplicaciones. En ese sentido, la encapsulación resulta en una alternativa de protección ideal para los aceites esenciales, y la inclusión molecular tiene ventajas frente a otros métodos de encapsulación, pero el método y temperatura de secado puede influenciar en sus características y estabilidad. Por esta razón, se microencapsuló al aceite esencial de naranja en beta-ciclodextrina (β-CD); y se evaluó el efecto del secado por estufa, liofilización y atomización (160, 180 y 200 °C) sobre la humedad, actividad de agua, eficiencia de encapsulación, rendimiento y estabilidad (82% de humedad relativa por 36 días). Las micropartículas fueron analizadas mediante microscopía electrónica de barrido (MEB), y espectroscopia infrarroja por transformada de Fourier (FTIR). El mejor método de secado fue la liofilización alcanzando una eficiencia de encapsulación de 97,35%, humedad 1,76%, actividad de agua 0,54, y una baja higroscopicidad de 0,20%. Los resultados por FTIR encontraron la formación y pérdida de algunos enlaces en el aceite esencial de naranja y la beta-ciclodextrina, posiblemente por efecto de la temperatura. Las micropartículas liofilizadas presentaron una mejor estabilidad en el almacenamiento logrando una eficiencia final de 52,53% con baja humedad y actividad de agua. Este estudio permite establecer el mejor método de secado en casos de una inclusión molecular; lo cual puede ser útil en aplicaciones futuras al desarrollar productos.

Abstract The present study is the first to investigate the chemical composition, antimicrobial and larvicidal activities of the essential oils from the leaves of Syzygium attopeuense (Gagnep.) Merr. & L.M.Perry and Syzygium tonkinense (Gagnep.) Merr. & L.M.Perry collected in Vietnam. The essential oils were extracted by hydrodistillation and analyzed by GC and GC–MS. The study indicated the presence of a high percentage of sesquiterpenes in both investigated essential oils. The major components of S. attopeuense essential oil were bicyclogermacrene (24.26%), (E)-caryophyllene (11.72%), and (E)-β-ocimene (6.75%), whereas S. tonkinense essential oil was dominated by (E)-caryophyllene (80.80%). The antimicrobial activity of essential oils was evaluated by broth microdilution assay to determine the minimum inhibitory concentration (MIC) and median inhibitory concentration (IC50). Both essential oils exhibited remarkable inhibitory activity against all tested Gram-positive bacteria and yeast than Gram-negative bacteria. Among them, essential oils of S. attopeuense and S. tonkinense possessed the strongest activity against Enterococcus faecalis (MIC = 4.00 μg/mL; IC50 = 1.69 μg/mL) and Candida albicans (MIC = 16.00 μg/mL; IC50 = 8.67 μg/mL), respectively. Furthermore, the larvicidal activity of essential oils was tested using fourth-instar larvae of Aedes aegypti. Results from the larvicidal test revealed that both essential oils had an excellent inhibitory effect against A. aegypti larvae with LC50 values from 25.55 to 30.18 μg/mL and LC90 values from 33.00 to 39.01 μg/mL. Our findings demonstrate that the essential oil extracted from S. attopeuense and S. tonkinense are potential sources of natural antimicrobials and can act as inexpensive mosquito larvicidal agents. composition Gagnep. Gagnep (Gagnep. Merr LMPerry L M Perry Vietnam GCMS MS GC–MS S 24.26%, 2426 24.26% , 24 26 (24.26%) Ecaryophyllene E caryophyllene 11.72%, 1172 11.72% 11 72 (11.72%) Eβocimene β ocimene 6.75%, 675 6.75% 6 75 (6.75%) 80.80%. 8080 80.80% . 80 (80.80%) MIC IC50. IC (IC50) Grampositive Gram positive Gramnegative negative them 400 4 00 4.0 μgmL μg mL IC5 169 1 69 1.6 1600 16 16.0 867 8 67 8.6 μg/mL, respectively Furthermore fourthinstar fourth instar A LC LC5 2555 25 55 25.5 3018 30 18 30.1 LC9 3300 33 33.0 3901 39 01 39.0 agents (Gagnep 242 24.26 2 (24.26% 117 11.72 7 (11.72% 6.75 (6.75% 808 80.80 (80.80% (IC50 40 0 4. 1. 160 16. 86 8. 255 5 25. 301 3 30. 330 33. 390 39. 24.2 (24.26 11.7 (11.72 6.7 (6.75 80.8 (80.80 (IC5 24. (24.2 11. (11.7 6. (6.7 80. (80.8 (IC (24. (11. (6. (80. (24 (11 (6 (80 (2 (1 ( (8

Resumo O presente estudo é o primeiro a investigar a composição química, as atividades antimicrobiana e larvicida dos óleos essenciais das folhas de Syzygium attopeuense (Gagnep.) Merr. & L.M.Perry e Syzygium tonkinense (Gagnep.) Merr. & L.M.Perry coletadas no Vietnã. Os óleos essenciais foram extraídos por hidrodestilação e analisados por GC e GC–MS. O estudo indicou a presença de alta porcentagem de sesquiterpenos em ambos os óleos essenciais investigados. Os principais componentes do óleo essencial de S. attopeuense foram biciclogermacreno (24,26%), (E)-cariofileno (11,72%) e (E)-β-ocimeno (6,75%), enquanto o óleo essencial de S. tonkinense foi dominado por (E)-cariofileno (80,80%). A atividade antimicrobiana dos óleos essenciais foi avaliada pelo ensaio de microdiluição em caldo para determinar a concentração inibitória mínima (CIM) e a concentração inibitória mediana (IC50). Ambos os óleos essenciais exibiram notável atividade inibitória contra todas as bactérias Gram-positivas e leveduras testadas do que bactérias Gram-negativas. Entre eles, os óleos essenciais de S. attopeuense e S. tonkinense possuíam a atividade mais forte contra Enterococcus faecalis (CIM = 4,00 μg/mL; IC50 = 1,69 μg/mL) e Candida albicans (CIM = 16,00 μg/ml; IC50 = 8,67 μg/ml), respectivamente. Além disso, a atividade larvicida de óleos essenciais foi testada usando larvas de quarto instar de Aedes aegypti. Os resultados do teste larvicida revelaram que ambos os óleos essenciais tiveram um excelente efeito inibitório contra larvas de A. aegypti com valores de CL50 de 25,55 a 30,18 μg/ml e valores de CL90 de 33,00 a 39,01 μg/ml. Nossos achados demonstram que o óleo essencial extraído de S. attopeuense e S. tonkinense são fontes potenciais de antimicrobianos naturais e podem atuar como agentes larvicidas baratos para mosquitos. química Gagnep. Gagnep (Gagnep. Merr LMPerry L M Perry Vietnã GCMS MS GC–MS investigados S 24,26%, 2426 24,26% , 24 26 (24,26%) Ecariofileno E cariofileno 11,72% 1172 11 72 (11,72% Eβocimeno β ocimeno 6,75%, 675 6,75% 6 75 (6,75%) 80,80%. 8080 80,80% . 80 (80,80%) CIM IC50. IC (IC50) Grampositivas Gram positivas Gramnegativas. Gramnegativas negativas. negativas Gram-negativas eles 400 4 00 4,0 μg/mL μgmL μg mL IC5 169 1 69 1,6 1600 16 16,0 μgml ml 867 8 67 8,6 μg/ml, μg/ml) respectivamente disso CL CL5 2555 25 55 25,5 3018 30 18 30,1 CL9 3300 33 33,0 3901 39 01 39,0 mosquitos (Gagnep 242 24,26 2 (24,26% 11,72 117 7 (11,72 6,75 (6,75% 808 80,80 (80,80% (IC50 40 0 4, 1, 160 16, 86 8, 255 5 25, 301 3 30, 330 33, 390 39, 24,2 (24,26 11,7 (11,7 6,7 (6,75 80,8 (80,80 (IC5 24, (24,2 11, (11, 6, (6,7 80, (80,8 (IC (24, (11 (6, (80, (24 (1 (6 (80 (2 ( (8

Abstract The genus Psidium, belonging to the family Myrtaceae, encompasses several plant species rich in essential oils. Several studies involving different research areas have shown promising results for essential oils, which has attracted interest from diverse sectors, including pharmaceutical, food, and cosmetic industries. Thus, the objective of this study was to evaluate the biological activity of the essential oil extracted from Psidium bahianum leaves (EOPb) collected in an Atlantic Forest remnant in the northern coast of the state of Bahia, Brazil. EOPb was extracted by steam distillation and analyzed through proton nuclear magnetic resonance (1H-NMR). The free radical scavenging activity was assessed using the DPPH methodology (analyzing the scavenging of the stable free radical 1,1-diphenyl-2-picrylhydrazyl). Antimicrobial disk diffusion assays were conducted; toxicity was determined through assays on sheep erythrocytes and Artemia salina. 1H-NMR evaluation showed the presence mainly of monoterpenes and sesquisterpenes. The percentage of antioxidant activity was 18.03±2.53 53 for 125 125 µg mL-1. Antimicrobial assays showed that the essential oil at a concentration of 10 mg mL-1 inhibited the growth of the microorganisms Staphylococcus aureus, Bacillus subtilis, B. cereus, Micrococcus luteus, Escherichia coli, Aspergillus niger, Candida albicans, and C. glabrata. The toxicity results indicated that concentrations of EOPb at 10, 100, 250, and 500 µg mL-1 were not toxic to sheep erythrocytes. The toxicity assay on A. salina showed that the lethal concentration for 50% of individuals (LC50) within 24 and 48 hours were 371.48 and 302 µg mL-1 of EOPb, respectively, which were considered moderately toxic, whereas the LC50 within 72 horas was 33.11 µg mL-1, considered highly toxic. These findings are promising, as the essential oil from P. bahianum leaves showed antimicrobial activity against both Gram-positive and Gram-negative bacteria and fungi. The data obtained for the essential oil toxicity in A. salina could be tested on different tumor cell lines. Myrtaceae oils sectors pharmaceutical food industries Thus (EOPb Bahia Brazil 1HNMR. 1HNMR HNMR 1H NMR . H (1H-NMR) analyzing 1,1diphenyl2picrylhydrazyl. 11diphenyl2picrylhydrazyl diphenylpicrylhydrazyl 1,1 diphenyl 2 picrylhydrazyl 1 1,1-diphenyl-2-picrylhydrazyl) conducted sesquisterpenes 1803253 18 03 18.03±2.5 5 12 mL1. mL1 mL 1. mL- aureus subtilis B cereus luteus coli niger albicans C glabrata 100 250 50 A LC (LC50 4 37148 371 371.4 30 respectively LC5 7 3311 33 11 33.1 mL1, 1, P Grampositive Gram positive Gramnegative negative fungi lines (1H-NMR 1diphenyl2picrylhydrazyl 1,1diphenyl2picrylhydrazyl 1,1-diphenyl-2-picrylhydrazyl 180325 0 18.03±2. 25 (LC5 3714 37 371. 3 331 33. 18032 18.03±2 (LC 1803 18.03± 180 18.03 18.0 18.

Resumo O gênero Psidium, pertencente à família Myrtaceae é rico em óleos essenciais que vêm sendo utilizados na indústria farmacêutica, alimentícia e na estética. Desse modo, o objetivo geral deste estudo foi avaliar a atividade biológica do óleo essencial de Psidium bahianum coletadas em remanescente de Mata Atlântica no Litoral Norte da Bahia, Brasil. O óleo essencial (OEPb) foi obtido das folhas do P. bahianum por arraste a vapor d'água. O OEPb foi analisado pela Ressonância magnética nuclear de H1. A atividade sequestradora de radicais livres foi avaliada pela metodologia de DPPH (analisando a eliminação do radical livre estável 1,1-difenil-2-picrilhidrazil). Foram realizados testes antimicrobianos em difusão em disco, e para a determinação da atividade tóxica realizou-se através dos ensaios em hemácias de carneiro e Artemia salina. O estudo de ressonância demonstrou principalmente a presença de monoterpenos, dentre eles o linalol, e sequisterpenos. A porcentagem da atividade antioxidante foi de 18,03 ± 2,53 53 para 125 µg /mL. No ensaio antimicrobiano o óleo essencial inibiu o crescimento dos microrganismos Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Micrococcus luteus, Escherichia coli, Aspergillus niger, Candida albicans e Candida glabrata testados na concentração de 10mg/mL. Os resultados da toxicidade demonstraram que nas concentrações de 10 e 100, 250 e 500µg/mL, o óleo essencial não é tóxico para hemácias de carneiro. No teste de toxicidade em Artemia salina, os resultados mostram que em 24 e 48 horas da DL50 é de 371,48 e 302µg/mL de óleo essencial sendo considerados moderadamente tóxicos e em 72 horas a DL 50 é de 33,11µg/mL considerado altamente tóxico. Os dados alcançados são promissores, uma vez que o óleo essencial de P. bahianum demostrou atividade antimicrobiana para bactérias Gram positiva e negativa e para fungos. Os dados obtidos de toxicidade em A. salina para o óleo essencial poderá ser testado em diferentes linhagens tumorais. farmacêutica estética modo Bahia Brasil (OEPb P dágua. dágua d água. água d'água H1 H analisando 1,1difenil2picrilhidrazil. 11difenil2picrilhidrazil difenilpicrilhidrazil 1,1 difenil 2 picrilhidrazil . 1 1,1-difenil-2-picrilhidrazil) disco realizouse realizou se monoterpenos linalol sequisterpenos 1803 18 03 18,0 253 2,5 5 12 mL /mL aureus subtilis cereus luteus coli niger 10mgmL mgmL 10mg mg 10mg/mL 100 25 500µgmL µgmL 500µg 500µg/mL 4 DL5 37148 371 371,4 302µgmL 302µg 7 3311µgmL 33 11µg promissores fungos tumorais 1difenil2picrilhidrazil 1,1difenil2picrilhidrazil 11 1, 1,1-difenil-2-picrilhidrazil 180 0 18, 2, 3714 37 371, 3

Abstract Bacterial contamination causes irreparable losses in the performance of alcoholic fermentation. Antibiotics are used to control these microorganisms, but they generate residues and cause microbial resistance. Today the only commercial product used by the mills is hops, but it is very expensive. As an alternative, the objective of this work was to evaluate the feasibility of using extracts from plants grown in the Cerrado for antimicrobial control during an alcoholic fermentation to replace antibiotics. Hydraethanolic extracts of leaves and essential oil of the following species were tested: Schinus terebinthifolius Raddi, Serjania erecta, Serjania marginata, Campomanesia adamantium and Syzygium cumini. Only the extract of Serjania marginata did not show any activity against the bacterium Bacillus sp. Both the essential oils as well as the hydroalcoholic extracts of S. terebinthifolius and C. adamantium and the extract of S. erecta showed antibacterial activity without harming the yeast, with potential to replace the hops. microorganisms resistance hops expensive alternative antibiotics tested Raddi cumini sp S C yeast

Resumo A contaminação bacteriana provoca perdas irreparáveis no desempenho da fermentação alcoólica. Antibióticos são utilizados para controlar esses microrganismos, mas geram resíduos e causam resistência microbiana. Hoje o único produto comercial utilizado pelas fábricas é o lúpulo, mas é muito caro. Como alternativa, o objetivo deste trabalho foi avaliar a viabilidade da utilização de extratos de plantas cultivadas no Cerrado para controle antimicrobiano durante uma fermentação alcoólica em substituição a antibióticos. Foram testados extratos hidroetanólicos de folhas e óleo essencial das seguintes espécies: Schinus terebinthifolius Raddi, Serjania erecta, Serjania marginata, Campomanesia adamantium e Syzygium cumini. Apenas o extrato de Serjania marginata não apresentou atividade contra a bactéria Bacillus sp. Tanto os óleos essenciais como os extratos hidroetanólicos de S. terebinthifolius e C. adamantium e o extrato de S. erecta apresentaram atividade antibacteriana sem agredir a levedura, com potencial para substituir o lúpulo. microrganismos microbiana lúpulo caro alternativa antibióticos espécies Raddi cumini sp S C levedura