Abstract This study aimed to evaluate the coating based on Amaranthus flour (AF), montmorillonite, and three essential oils (clove, muña, and matico) to extend the shelf life of minimally processed mango. The mango cubes were divided into four different treatments. T1- control (uncoated mango), T2 (0.3% w/v of clove), T3 (0.3% w/v of muña), and T4 (0.3% w/v of matico). All treatments had 0.6% w/v Amaranth flour and 0.02% w/v montmorillonite (MMT) and were subjected to 5°C for 12 days. Water activity (Aw), pH, Total soluble solids, acidity, weight loss, color, texture, and antimicrobial activity were evaluated for each treatment. Matico treatment maintained pH and had the lowest count of yeast and mold forming units on mango (3.47 log UFC g-1). On the last day of storage, all coating treatments showed less weight loss and favorable results than the control. The matico treatment showed higher efficiency for mango preservation.

This study investigated the efficacy of a commercial phytogenic-based premixed feed additive (PFA) in treating combined Lawsonia intracellularis and Brachyspira hyodysenteriae infections in finishing pigs, with tiamulin/lincomycin treatment as the control. Pigs aged 20 weeks were allocated to PFA treatment (11 pens, 45 pigs per pen) and control (7 pens, 43 pigs per pen) groups for a seven-week experimental period. Floor faecal samples and rectal swabs were collected weekly, and the percentage of pigs per pen with diarrhoea was recorded weekly. The bacterial contents of the samples were determined using real-time polymerase chain reaction, and at the end of the experiment, histological changes in ileal samples were examined. There was an intermittent decrease in L. intracellularis in the control group (from 4.85 to 0.82 DNA log10 copies/μl) and a continuous reduction in L. intracellularis in the PFA group (from 5.69 to 0.64 DNA log10 copies/μl) over a six-week period. B. hyodysenteriae was not detected in rectal swabs from the control group at week six, and an intermittent decrease in B. hyodysenteriae, from 3.04 to 0.26 DNA log10 copies/μl, was observed in the PFA group. Bacterial DNA in the floor faecal samples declined during the seven-week experimental period, as found for the rectal swabs. There were no cases of diarrhoea from week two onwards in the control group and week three onwards in the PFA group. The results of this study indicate that a PFA rich in essential oils has a therapeutic effect comparable to that of tiamulin/lincomycin in pigs with proliferative enteropathy and swine dysentery.

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 (

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 (

Abstract Introduction: The genus Myrcianthes ranges from southern Florida to Chile, including the Caribbean, and the species Myrcianthes storkii is a shrub or tree found in Costa Rica and western Panama, in wet to very rainy, cloud, and oak forests (altitude 1300-3150m). Objective: To identify the chemical composition of essential oils from leaves, floral buds, and twigs of M. storkii of Costa Rica. Methods: We obtained the essential oils through hydrodistillation in a Clevenger-type apparatus. The chemical composition of the oils was done by GC/FID and GC/MS, using the retention indices on DB- 5 and Carbowax types of capillary columns in addition to mass spectra. Results: The oils consisted mainly of terpenoids (55,45-87,75%). A total of 281 compounds accounted for 91,27-74,56% of the total amount of oils. The major constituents from the leaf oil were myrcene (17,44%), cis-calamenene (12,60%), α-pinene (5,48%), (E)-caryophyllene (5,16%), limonene (3,91%), p-cymene(3,71%), 1,8-cineole (2,80%), and α-humulene (2,80%). The floral bud essential oil consisted mainly of α-pinene (15,23%), cis-calamenene (12,70%), myrcene (8,59%), 1,8-cineole (4,26%), germacrene B (3,65%), α-humulene (3,55%), and (E)-caryophyllene oxide (2,93%). The major components of twig oil were cis-calamenene (11,31%), palmitic acid (7,99%), (E)-caryophyllene (4,68%), 𝛿-cadinene (3,28%), cubenol (3,24%), and (Z)-caryophyllene oxide (2,94%). Conclusion: The presence of a significant quantity of myrcene and cis-calamenene seems to be characteristic of this species.

Resumen Introducción: El género Myrcianthes se extiende desde el sur de Florida hasta Chile, incluyendo el Caribe, y la especie Myrcianthes storkii es un arbusto o árbol que se encuentra en Costa Rica y el oeste de Panamá, en bosques húmedos, muy lluviosos, de neblina y robles (altitud de 1300 a 3150 m). Objetivo: Identificar la composición química de los aceites esenciales de las hojas, yemas florales y ramas de M. storkii de Costa Rica. Métodos: Obtuvimos los aceites esenciales mediante hidrodestilación en un aparato de tipo Clevenger. Determinamos la composición química de los aceites mediante cromatografía de gases con detector de ionización de llama (GC/FID) y cromatografía de gases acoplada a espectrometría de masas (GC/MS). Usamos los índices de retención en columnas capilares de tipos DB-5 y Carbowax, además de espectros de masas. Resultados: Los aceites están compuestos principalmente por terpenoides (55,45-87,75%). Identificamos 281 compuestos, que representaron el 91,27-74,56% de la cantidad total de los aceites. Los principales constituyentes del aceite de hoja fueron mirceno (17,44%), cis-calameneno (12,60%), α-pineno (5,48%), (E)- cariofileno (5,16%), limoneno (3,91%), p-cimeno (3,71%), 1,8-cineol (2,80%) y α-humuleno (2,80%). El aceite esencial de las yemas florales consistió principalmente en α-pineno (15,23%), cis-calameneno (12,70%), mirceno (8,59%), 1,8-cineol (4,26%), germacreno B (3,65%), α- humuleno (3,55%) y óxido de (E)-cariofileno (2,93%). Los componentes principales del aceite de las ramas fueron cis-calameneno (11,31%), ácido palmítico (7,99%), (E)-cariofileno (4,68%), δ-cadineno (3,28%), cubenol (3,24%) y óxido de (Z)-cariofileno (2,94%). Conclusión: La presencia de una cantidad significativa de mirceno y cis- calameneno parece ser característica de esta especie.

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 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.

RESUMEN Los aceites esenciales de Melaleuca alternifolia L. (MaEO), extraídos mediante destilación al vapor de sus hojas, ofrecen múltiples beneficios. El objetivo del estudio fue determinar las propiedades fisicoquímicas y biológicas, como la densidad relativa, la densidad absoluta, el índice de acidez, el índice de saponificación, el índice de éster, el punto de congelación, la retención de fragancia, la actividad antioxidante y antibacteriana del MaEO. Se utilizó análisis de cromatografía de gases-espectrometría de masas (GC-MS) para analizar la composición química de los aceites esenciales (AE), y los resultados obtenidos mostraron que se identificaron y cuantificaron 45 compuestos; entre ellos, el componente principal fue terpinen-4-ol (44,55%). Además, la capacidad antioxidante (CA) se evaluó mediante el ensayo de 2,2-difenil-1-picrilhidrazilo (DPPH) con la concentración inhibidora media máxima (IC50) de 360 mg mL-1. Asimismo, MaEO también tuvo una excelente actividad antibacteriana (AA) contra ciertos tipos de bacterias, utilizando el método de difusión en disco de papel para pruebas de susceptibilidad a los antibióticos. El diámetro de las zonas inhibidoras fueron 12,33, 14, 15,67 y 24,33 mm para Bacillus cereus (ATCC 11778), Staphylococcus aureus (ATCC 25923), Salmonella enterica (ATCC 13076) y Escherichia coli (ATCC 25922), respectivamente.

ABSTRACT Melaleuca alternifolia L. essential oils (MaEO), extracted through steam, distillation of its leaves, offer a multitude of benefits. The aim of the study was to determine the physicochemical and biological properties, such as relative density, absolute density, acid value, saponification value, ester value, freezing point, fragrance retention, antioxidant and antibacterial activity of MaEO. Gas chromatography-mass spectrometry (GC-MS) analysis was used to analyze the chemical composition of essential oils (EO), and the obtained results displayed those 45 compounds were identified and quantified; among them, the main component was Terpinen-4-ol (44.55%). In addition, the antioxidant capacity (AC) was evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay with the half maximal inhibitory concentration (IC50) of 360 mg mL-1. Moreover, MaEO also had excellent antibacterial activity (AA) against certain types of bacteria, using the paper disc diffusion method for antibiotic susceptibility testing. The diameter of the inhibitory zones were 12.33, 14, 15.67, and 24.33 mm for Bacillus cereus (ATCC 11778), Staphylococcus aureus (ATCC 25923), Salmonella enterica (ATCC 13076), and Escherichia coli (ATCC 25922), respectively.

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.

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 are one of the most important products in the agricultural and food industry, as they are obtained from aromatic plants using various extraction techniques, such as steam distillation or hydrodistillation. However, these methods present challenges, such as low efficiency, limited selectivity, extensive use of solvents and long extraction times. Moreover, the quality of the oils obtained can be affected by hydrolysis or oxidation due to the duration and amount of water used in the process. This review updates the information on Clevenger-type hydrodistillation extraction of four high-value commercial plant species: Matricaria chamomilla, Rosmarinus officinalis, Origanum vulgare, and Eucalyptus spp. The aim is to evaluate the results of original articles, considering the origin and characteristics of the plant material, extraction conditions, yield and metabolites. The search covered a 10-year period (2013-2023) in Scopus, Web of Science, PubMed, and Google Scholar, using keywords such as species names and terms “essential oils” and “hydrodistillation”, with Boolean connectors such as OR, AND or NOT. The results show that quality and yield are influenced by factors such as geographical regions of origin, plant part used, drying techniques or extraction conditions (plant material/water ratio, extraction temperature, extraction time, etc.). In future research, the conditions associated with the plant material and the extraction process need to be optimized in obtaining high quality essential oils.

Resumen En este trabajo se identifican los compuestos químicos presentes en los aceites esenciales de cinco especies de frailejones y se evaluó su actividad biológica frente a diferentes microorganismos. Los aceites esenciales de las hojas frescas de Espeletia argentea, Espeletia barclayana, Espeletia killipii, Espeletia summapacis y Espeletiopsis corymbosa fueron extraídos por hidrodestilación. La composición química de los aceites esenciales fue determinada mediante cromatografía de gases acoplada a espectrometría de masas (GC-MS). Los aceites esenciales de algunas de las especies fueron evaluados frente a hongos (Fusarium sp., Chaetomium sp., Botrytis sp., Penicillium sp., Alternaria sp.), la bacteria Staphylococcus aureus ATCC 25923, así como frente a la levadura Candida sp. mediante el método de difusión en agar. Los compuestos mayoritarios identificados en los aceites esenciales fueron α-pineno, β-pineno, sabineno, p-cimeno, limoneno, α- y β-felandreno. Por otra parte, los aceites esenciales de cuatro especies de Espeletia mostraron actividad frente a Fusarium sp. y Chaetomium sp. en comparación con un control comercial. Además, los aceites de E. argentea y E. corymbosa fueron evaluados posteriormente frente a cepas de Botrytis sp., Penicillium sp. y Alternaria sp. Se encontró que el aceite esencial de E. argentea tiene un porcentaje de inhibición del 30% al 80% en las cepas evaluadas.

Abstract This study identifies the chemical compounds present in the essential oils of five species of frailejones and evaluates their biological activity against various microorganisms. The essential oils from the fresh leaves of Espeletia argentea, Espeletia barclayana, Espeletia killipii, Espeletia summapacis, and Espeletiopsis corymbosa were extracted through hydrodistillation. The chemical composition of the essential oils was determined using gas chromatography-mass spectrometry (GC-MS). The essential oils of some species were tested against fungi (Fusarium sp., Chaetomium sp., Botrytis sp., Penicillium sp., Alternaria sp.) and the bacteria Staphylococcus aureus ATCC 25923, as well as the yeast Candida sp., using the agar diffusion method. The major compounds identified in the essential oils were α-pinene, β-pinene, sabinene, p-cymene, limonene, and α- and β-phellandrene. Additionally, the essential oils of four Espeletia species exhibited activity against Fusarium sp. and Chaetomium sp. when compared to a commercial control. Furthermore, the oils of E. argentea and E. corymbosa were subsequently tested against strains of Botrytis sp., Penicillium sp., and Alternaria sp. It was found that the essential oil of E. argentea exhibited inhibition rates ranging from 30% to 80% against the tested strains.

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 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 estudio presenta una caracterización de los compuestos orgánicos volátiles encontrados en la "Cebolla Pereirana", una variedad endémica de cebolla de rama en Colombia para la cual no se había informado previamente sobre su composición. El análisis se realizó utilizando cuatro diferentes fibras por la técnica HS-SPME/GC-MS. Los resultados revelaron que las cebollas Pereirana picadas liberan hasta 29 compuestos diferentes, con concentraciones hasta 20 veces más altas que las observadas en otras especies de cebolla evaluadas (Biónica, Veleña y Veleña Sonsón). La mayoría de estos compuestos son de origen organosulfurado, incluyendo el disulfuro de dipropilo, (E)-1-(Prop-1-en-1-il)-2-propildisulfano, disulfuro, metil 1-(metiltio) propilo, trisulfuro de dipropilo y (E)-1-(Prop-1-en-1-il)-3-propiltrisulfano. Además, la extracción de aceites esenciales mediante arrastre por vapor de las cebollas Pereirana permitió identificar hasta 70 compuestos diferentes. El análisis de correspondencia simple (SCA) reveló que las especies de cebolla Veleña y Veleña Sonsón comparten compuestos comunes, pero difieren significativamente de las variedades Biónica y Pereirana cultivadas en Risaralda, Colombia. Estos hallazgos sugieren aplicaciones potenciales en las industrias farmacéutica, agrícola y alimentaria, allanando el camino para futuras investigaciones y utilización industrial.

ABSTRACT The study presents a characterization of the volatile organic compounds found in both raw and the essential oil of the "Pereirana Onion", an endemic Colombian Welsh onion variety for which the composition has not been previously reported. The analysis was conducted using four distinct fibers through the HS-SPME/GC-MS method. The results revealed that chopped Pereirana onions release as many as 29 different compounds, with concentrations up to 20 times higher than those observed in other evaluated onion species (Biónica, Veleña, and Veleña Sonsón). Most of these compounds are sulfur-based, including dipropyl disulfide, (E)-1-(Prop-1-en-1-yl)-2-propyldisulfane, disulfide, methyl 1-(methylthio) propyl, dipropyl trisulphide, and (E)-1-(Prop-1-en-1-yl)-3-propyltrisulfane. Furthermore, steam extraction of essential oils from Pereirana onions led to the identification of up to 70 different compounds. Simple correspondence analysis (SCA) revealed that Veleña and Veleña Sonsón onion species share common compounds but significantly differ from Biónica and Pereirana varieties cultivated in Risaralda, Colombia. These findings suggest potential applications in the pharmaceutical, agricultural, and food industries, paving the way for future research and industrial utilization.

RESUMEN En el presente trabajo, se determinó la composición química volátil de los aceites esenciales colombianos de Eryngium foetidum L. y Clinopodium brownei (Sw.) Kuntze, extraídos por hidrodestilación, usando la técnica de cromatografía de gases acoplada a espectrometría de masas (CG-EM). El aceite esencial de hojas de E. foetidum está compuesto en su mayoría de aldehídos alifáticos, principalmente 2-dodecenal (43,0%), mientras que en el aceite esencial de las partes aéreas de C. brownei contiene mentona (54,3%), pulegona (17,7%), y neomentol (16,1%). La susceptibilidad de las cepas bacterianas Staphylococcus aureus subsp. aureus (ATCC 11632), Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 13883), y Pseudomonas aeruginosa (ATCC 27853) a ambos aceites esenciales se probó mediante ensayos de difusión en agar. Se encontró que el aceite esencial de E. foetidum inhibe el crecimiento de S. aureus (90% a 150 µg mL-1). Las pruebas de microdilución en caldo determinaron que la MIC y MBC de E. foetidum contra S. aureus fue de 105 y 150 μg mL-1, respectivamente. El 2-dodecenal tuvo actividad antibacteriana fuerte contra S. aureus con MIC y MBC de 105 μg mL-1 (98%). Las combinaciones binarias de 2-dodecenal y S-limoneno o 2,4,6-trimetoxibenzaldehido tuvieron efecto indiferente en las pruebas de tablero de ajedrez, por lo que se podría afirmar que la actividad antibacteriana del aceite esencial de E. foetidum se debe principalmente a la acción del 2-dodecenal.

ABSTRACT In the present work, the volatile chemical composition was determined for the essential oils of Colombian Eryngium foetidum L. and Clinopodium brownei (Sw.) Kuntze, extracted by hydrodistillation, using gas chromatography coupled with mass spectrometry (GC-MS) technique. The essential oil of E. foetidum leaves is composed mostly of aliphatic aldehydes, mainly 2-dodecenal (43.0%), while the essential oil of the aerial parts of C. brownei contains menthone (54.3%), pulegone (17.7%), and neomenthol (16.1%). The susceptibility of the bacterial strains Staphylococcus aureus subsp. aureus (ATCC 11632), Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 13883), and Pseudomonas aeruginosa (ATCC 27853) to both essential oils was tested with agar diffusion assays. It was found that the E. foetidum essential oil inhibits the growth of S. aureus (90% at 150 µg mL-1). Broth microdilution tests determined that the MIC and MBC of the E. foetidum essential oil against S. aureus were 105 and 150 μg mL-1, respectively. 2-dodecenal had strong antibacterial activity against S. aureus with MIC and MBC of 105 μg mL-1 (98%). Binary combinations of 2-dodecenal and S-limonene or 2,4,6-trimethoxybenzaldehyde had an indifferent effect in checkerboard tests, so it could be stated that the antibacterial activity of the essential oil of E. foetidum is mainly due to the action of the 2-dodecenal.

RESUMEN Introducción. - El "nogal peruano" es un árbol grande distribuido en varias regiones del Perú, principalmente en áreas de bosques secundarios tardíos y maduros. Las especies proveedoras de aceites esenciales antioxidantes son consideradas valiosas para aplicaciones en el área de la salud. Los aceites esenciales con diversos constituyentes muestran efectos sinérgicos y pueden ser una alternativa eficaz para prevenir enfermedades. Objetivos. - Evaluar la composición química, actividad antioxidante y anti-Candida albicans del aceite esencial de hojas de Juglans neotropica Diels. Materiales y métodos. - Se obtuvo el aceite esencial mediante una destilación por arrastre de vapor de agua. Se analizó su composición química por un análisis GC-MS y se evaluó su actividad antioxidante según los métodos de DPPH• y ABTS•+. Además, se determinó su actividad anti-Candida albicans, adaptando protocolos, utilizando ketoconazol como referencia. Se diluyó el aceite en DMSO y se incubó con Candida albicans, midiendo el crecimiento mediante lecturas a las 24 horas en microplacas de 96 pocillos. Resultados. - El análisis de la composición química por GS-MS reveló la presencia de compuestos como el fitol, α-pineno, α-caryophyllene, copaeno y D-limoneno. Según el método DPPH•, el aceite esencial mostró un IC50 de 52,25 ul/ml. Con el método ABTS•+ el IC50 fue de 34,65 ul/ml. Sin embargo, no se observó actividad anti-Candida albicans. Conclusiones. - Los compuestos químicos de mayor importancia del aceite esencial de hojas de Juglans neotropica Diels fueron el α-pineno, D-limoneno y Copaeno. Además, presentó una actividad antioxidante regular y una nula actividad anti-Candida albicans.

ABSTRACT Introduction. - The "nogal peruano" is a large tree distributed in several regions of Peru, mainly in areas of late secondary and mature forests. Species supplying antioxidant essential oils are considered valuable for health applications. Essential oils with various constituents show synergistic effects and can be an effective alternative to prevent diseases. Objectives. - To evaluate the chemical composition, antioxidant and anti-Candida albicans activity of the essential oil of Juglans neotropica Diels leaves. Materials and methods. - The essential oil was obtained by steam distillation. Its chemical composition was analyzed by GC-MS analysis and its antioxidant activity was evaluated according to DPPH• and ABTS•+ methods. In addition, its anti-Candida albicans activity was determined, adapting protocols, using ketoconazole as a reference. The oil was diluted in DMSO and incubated with Candida albicans, measuring growth by 24-hour readings in 96-well microplates. Results. - Chemical composition analysis by GS-MS revealed the presence of compounds such as phytol, α-pinene, α-caryophyllene, copaene and D-limonene. According to the DPPH• method, the essential oil showed an IC50 of 52.25 ul/ml. With the ABTS•+ method the IC50 was 34.65 ul/ml. However, no anti-Candida albicans activity was observed. Conclusion. - The most important chemical compounds of the essential oil of Juglans neotropica Diels leaves were α-pinene, D-limonene and Copaene. In addition, it presented regular antioxidant activity and null anti-Candida albicans activity.

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 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 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 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.