Antibacterial potential of essential oils against planktonic and sessile cells of Escherichia coli isolated from diarrhea cases in swine / Potencial antibacteriano de aceites esenciales contra células de Escherichia coli planctónicas y sésiles aisladas de diarrea porcina

Escherichia coli is a pathogen associated with infections in piglets in the post-weaning phase, its pathogenicity is related to the animal's susceptibility to bacterial enterotoxins. The objective of the present study was to determine the EOs activity against E. colistrain, in the form planktonic and sessile. Although the Disc-Diffusion tests to determine the Minimum Inhibitory Concentration, do not fully corroborate with the other analyzes of this study, it was noticed bacteria inhibition. The EOs were prepared at 0.4%, 0.8% and 1.0% for tests. The tested EOs were effective against E. coliplanktonic cells (p<0.05). As for the sessile cells, the most significant result was inhibition and 100% sessile cells at the concentration of 1.0% of Cymbopogon citratusEO. Although there was resistance in some treatments, the tested EOs demonstrated inhibition capacity, constituting promising alternatives for the control of E. coli, especially of planktonic cells.

Escherichia coli es un patógeno asociado con infecciones en lechones en la fase posterior al destete, su patogenicidad está relacionada con la susceptibilidad del animal a las enterotoxinas bacterianas. El objetivo del presente estudio fue determinar la actividad de contra E. coli, en la forma planctónico y sésil. Aunque las pruebas de difusión de disco para determinar la concentración inhibitoria mínima, no corroboran completamente con los otros análisis de este estudio, se observó inhibición de la bacteria. Las soluciones basadas en AE se prepararon al 0.4%, 0.8% y 1.0% para pruebas. Los AEs probados fueron efectivos contra las células planctónicas (p<0.05). En cuanto a las células sésiles, el resultado más significativo fue la inhibición y el 100% de las células sésiles a la concentración de 1,0% de Cymbopogon citratus. Aunque hubo resistencia en algunos tratamientos, los AEs probados demostraron capacidad de inhibición, constituyendo alternativas prometedoras para el control de E. coli, especialmente de células planctónicas.

A simple method for the determination of bioethanol from lignocellulosic materials using gas chromatography-flame ionisation detector (GC-FID)

Aims@#The utilisation of lignocellulosic biomass for bioethanol production reduces the dependency on fossil fuels as a source of energy and emission of greenhouse gas (GHG). However, studies in this emerging field are hampered by the cost of ethanol quantification methods. Due to the volatile nature of ethanol, the method for the quantification of bioethanol production should be reproducible and rapid to avoid any evaporation loss to the surroundings. Therefore, this study aimed to develop a simple, rapid and precise bioethanol quantification method using a gas chromatographyflame ionisation detector (GC-FID) without having to go through distillation process for ethanol purification.@*Methodology and results@#The bioethanol was produced via consolidated bioprocessing (CBP) using Trichoderma asperellum B1581 and paddy straw. The peak corresponding to ethanol was obtained at 2.347 min with a peak area of 189.66, equating to 0.159% (v/v) or 1.25 g/L ethanol. A comparison between the quantity of ethanol detected by GC-FID and spectrophotometric analysis (340 nm) showed no significant difference (p>0.05) in the amount of ethanol detected by GC analysis, thus validating the accuracy of the GC method.@*Conclusion, significance and impact of study@#This work presents a simple, precise and reliable method to determine the amount of bioethanol in the sample using a GC-FID. Currently, there are many GC-FID methods available for the determination of ethanol/alcohol in a human blood samples or in beverages but not in bioethanol samples. Thus, this method was developed to facilitate the determination of bioethanol in the samples produced from lignocellulosic materials.

Contenido de grasa saturada y trans en panes de panaderías de la ciudad de Medellín, Colombia / Saturated and trans fat content in the breads of bakeries in Medellín, Colombia

ANTECEDENTES: Se desconoce el contenido de grasas saturada (GS) y trans (Gtrans) en panes sin etiqueta y sin vigilancia por entidad regulatoria de Colombia. PROPÓSITO: Comparar el contenido de GS y Gtrans en panes de algunas panaderías de Medellín con lo reglamentado: 0,5 g/50 g de pan, para ambos tipos de grasa según resolución 2508 de 2012 del Ministerio de Salud. MATERIALES Y MÉTODOS: Se muestrearon 45 panes de tres tipos (aliñado, leche y croissant) en tres niveles socioeconómicos (NSE) según ubicación de la panadería. Se cuantificó grasa total gravimétricamente y GS y Gtrans por cromatografía de gases. RESULTADOS: El porcentaje de GS y Gtrans con respecto a la grasa total extraíble fue 43,8% y 0,6% en pan aliñado, 37,4% y 0,6% en pan leche y 32,2% y 0,9% en pan croissant, sin diferencia significativa entre ellos (p= 0,155 y 0,184, respectivamente). CONCLUSIONES: Comparado con la resolución 2508, el contenido de GS fue mayor al límite establecido en resolución y el contenido de Gtrans fue menor en pan aliñado, leche o croissant. Los panes evaluados en las panaderías del NSE bajo contenían mayor Gtrans que los otros.

BACKGROUND: The content of saturated (GS) and trans (Gtrans) fats in unlabeled and breads that are not regulated by the Colombian government is unknown. PURPOSE: To compare the content of GS and Gtrans in breads of bakeries in Medellín with the following regulation: 0.5 g/50 g of bread, for both types of fat according to the 2012 Ministry of Health resolution #2508. MATERIALS AND METHODS: 45 breads of three types (seasoned, milk and croissant) were sampled at bakeries from three socioeconomic levels (NSE) according to the location. Total fat was quantified gravimetrically and GS and Gtrans by gas chromatography. RESULTS: The percentage of GS and Gtrans with respect to the total extractable fat was 43.8% and 0.6% in seasoned bread, 37.4% and 0.6% in milk bread and 32.2% and 0.9% in croissant bread, with no significant difference by bread type (p= 0.155 and 0.184, respectively). CONCLUSIONS: GS content of sampled breadswas greater than the limit established in the resolution. Gtrans content was lower in seasoned bread andmilk bread compared to croissant. The breads evaluated in the bakeries of lower NSE contained higher Gtrans than the others.

Chemical composition and acaricidal activity of essential oils and selected terpenes from two species of Psidium in the Cerrado biome of Brazil against Tetranychus urticae / Composición química y actividad acaricida del aceite esencial y terpenos seleccionados de dos especies de Psidium de Cerrado Biome de Brasil contra Tetranychus urticae

The aim of this study was to investigate the chemical composition and acaricidal effect of two Psidium species essential oils and selected compounds on Tetranychus urticae. Essential oils from the leaves of Psidium laruotteanum and Psidium myrsinites were obtained through hydrodistillation, analyzed using CG-FID and CG-MS and evaluated for toxicity to T. urticae by fumigation and residual contact. The susceptibility of T. urticae to monoterpenes and sesquiterpenes was also investigated. The major constituents of the P. laruotteanum oil were (E)-nerolidol (9.6 ± 0.4%) and γ-terpinene (9.4 ± 0.6%) and the major constituents of the P. myrsinites oil were ß-caryophyllene (21.2 ± 0.9%) and α-humulene (10.3 ± 0.5%). Based on the LC50 estimates, no significant differences were found between the two oils regarding toxicity by fumigation or residual contact. ß-Caryophyllene and (E)-nerolidol had the highest level of toxicity, independently of the method investigated. The findings indicate that both oils and selected constituents, especially ß-caryophyllene and (E)-nerolidol, are promising as natural acaricidal agents that affect T. urticae through more than one mode of action.

Los aceites esenciales de las hojas de Psidium laruotteanum y Psidium myrsinites se obtuvieron por hidrodestilación, se analizaron por CG-FID y CG-MS, y se evaluaron sus toxicidades por fumigación y contacto residual contra Tetranychus urticae. Se investigó también la susceptibilidad del T. urticae a monoterpenos y sesquiterpenos. En el aceite esencial de P. laruotteanum, (E)-nerolidol (9.6 ± 0.4%) y γ-terpinene (9.4 ± 0.6%) se identificaron como constituyentes mayoritarios, mientras que en el aceite esencial de P. myrsinites, ß-caryophyllene (21.2 ± 0.9%) y α-humulene (10.3 ± 0.5%) se encontraron como mayoritarios. Con base en las CL50 estimadas, no se observaron diferencias significativas entre las toxicidades de los aceites por fumigación, y tampoco por contacto residual. ßCaryophyllene y (E)-nerolidol presentaron las mayores toxicidades, independientemente del método investigado. Estos resultados indican, que los dos aceites, así como los constituyentes seleccionados, entre los que se destacan ß-caryophyllene y (E)-nerolidol, son promisores agentes acaricidas naturales por actuar en el T. urticae por más de un mecanismo de acción.

Ocotea (Lauraceae) Amazonian essential oils chemical composition and their tyrosinase inhibition to use in cosmetics / Ocotea (Lauraceae) composición química de aceites esenciales amazónicos y su inhibición de la tirosinasa para usar en cosméticos

This study presents analyses on the chemistry, biology, pharmacology and chromatography of essential oils extracted from three species of the Ocotea genus: O. minor, O. ceanothifolia and O. leucoxylon. Leaves and stems, as well as the bark of O. minor, were processed using a modified Clevenger apparatus. Seven essential oils were obtained and analyzed using GC-FID and GC-MS, and their chemical compositions were determined. Assays of cytotoxicity, antioxidant and free radical scavenging activity, as well as tyrosinase and elastase inhibition were performed. In total, 25 constituents were identified, the principal being sesquiterpenes, such as spathulenol caryophyllene and its oxide. The oils did not present cytotoxicity using a hemolytic model, but also did not show antioxidant activity in the DPPH assay. Essential oil from stems of O. ceanothifolia, rich in spathulenol and caryophyllene oxide, demonstrated the capacity to inhibit 49.08% of tyrosinase activity at a concentration of 100 µg/mL. This research contributes to the chemical profile analysis of the three species of Ocoteathrough chemical investigations and biological activity, which are reported for the first time here in this study.

Este trabajo realiza un estudio químico, biológico, farmacológico y cromatográfico de aceites esenciales extraídos de tres especies del género Ocotea: O. minor, O. ceanothifoliay O. leucoxylon. Las hojas y tallos, así como la corteza de O. minor, se procesaron utilizando un aparato Clevenger modificado. Se obtuvieron siete aceites esenciales y se analizaron usando GC-FID y GC-MS, y se determinaron sus composiciones químicas. Se realizaron ensayos de citotoxicidad, actividad antioxidante y de atrapamiento de radicales libres, así como inhibición de tirosinasa y elastasa. En total, se identificaron 25 componentes, siendo los principales sesquiterpenos, como el spathulenol cariofileno y su óxido. Los aceites no presentaron citotoxicidad en un modelo hemolítico y tampoco mostraron actividad antioxidante en el ensayo con DPPH. El aceite esencial de tallos de O. ceanothifolia, rico en espatulenol y óxido de cariofileno, mostró capacidad para inhibir el 49.08% de la actividad de tirosinasa a una concentración de 100 µg/mL. Esta investigación contribuye al análisis del perfil químico de las tres especies de Ocotea a través de investigaciones químicas y actividad biológica la cual se informan por primera vez.

Composition in fatty acids of mature milk of nursing mothers / Composição em ácidos graxos do leite maduro de nutrizes

Abstract Objectives: to determine the fatty acid composition of mature milk of nursing mothers and its distribution according to some maternal variables. Methods: this is a cross-sectional observational epidemiological study based on the eva-luation of the fatty acid profile of mature human milk. Samples of mature breast milk were taken from 106 nursing mothers, by manual milking and who were after the 5th postpartum week. The milk fat extraction was carried out by using the Bligh and Dyer method and methy-lated with 0.25 mol/L sodium methoxide in methanol diethyl ether. The fatty acid of the milk profile was determined by a Gas Chromatograph equipped with a flame ionization detector. Results: among the saturated fatty acids, the highest values were observed for palmitic (C16:0), stearic (C18:0), myristic (C14:0) and lauric (C12:0) fatty acids, respectively. Among the monounsaturated fatty acids, there was a higher contribution of oleic (C18:1) and palmi-toleic (C16:1) fatty acids, respectively. The total essential fatty acids (linoleic and α-linolenic) was 14.94%. Conclusions: a low content of essential fatty acids in the breast milk of the nursing mothers was observed in the present study, which are important for infant growth and deve-lopment. We suggest the need to implement nutrition education strategies aimed for pregnant women and nursing mothers who should be advised to eat healthier foods.

Resumo Objetivos: determinar a composição em ácidos graxos do leite maduro de nutrizes e sua distribuição segundo algumas variáveis maternas. Métodos: trata-se de um estudo epidemiológico observacional, transversal realizado a partir da avaliação do perfil de ácidos graxos do leite humano maduro. Amostras de leite materno maduro foram obtidas de 106 nutrizes, a partir da 5ª semana pós-parto, por meio de ordenha manual. A extração da gordura do leite foi realizada através do método de Bligh e Dyer, e metiladas com metóxido de sódio 0,25 mol/L em metanol dietil - éter. O perfil de ácidos graxos do leite foi determinado por um Cromatógrafo a Gás equipado com detector por ionização de chamas. Resultados: dentre os ácidos graxos saturados, foram observados valores mais elevados para os ácidos graxos palmítico (C16:0), esteárico (C18:0), mirístico (C14:0) e láurico (C12:0), respectivamente. Entre os ácidos graxos mono-insaturados, verificou-se maior contribuição dos ácidos graxos oleico (C18:1) e palmitoleico (C16:1), respectivamente. O total de ácidos graxos essenciais (linoleico e α- linolênico) foi de 14,94%. Conclusões: foi observado baixo teor de ácidos graxos essenciais no leite materno das nutrizes do presente estudo, que são importantes para o crescimento e desenvolvimento do lactente, sugerindo-se a necessidade de implementação de estratégias de educação nutricional direcionadas a gestantes e nutrizes que devem ser orientadas a consumir alimentos mais saudáveis.

Anti-inflammatory and anti-nociceptive activities of essential oil of Waltheria indica / Actividades antiinflamatorias y nociceptivas del aceite esencial de Waltheria indica

This paper reports for the first time volatile compounds, anti-nociceptive and anti-inflammatory activities of essential oils from the leaves of Waltheria indica L. (Stericullaceae) growing in Nigeria. The essential oil was hydro-distilled and characterized by gas chromatography-flame ionization detection (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS) analyses. The anti-inflammatory activity was evaluated on carrageenan induced rat paw edema while the anti-nociceptive test was based on hot plate model. The hydro-distillation afforded 0.41% (dry weight basis) of light green oil. Forty compounds representing 99.8% were identified in the oil. The main constituents of the oil were limonene (34.7%), sabinene (21.2%) and citronellal (9.7%). The anti-nociceptive property of the essential oils statically inhibited edema development (p<0.001) at a dose of 200 and 400 mg/kg independent of time of exposure. However, the 100 mg/kg Waltheria indica essential oils (WIEO) displayed a relatively low inhibition (p<0.01-p>0.5) which declines as exposure time increases. The anti-inflammatory activities shows a steady rate and non-dose dependent activity (p<0.001) up to the 3rd h of inflammation study. Conversely, a sharp reduction at the rate of p<0.5, 0.1 and 0.01 for the 100, 200 and 400 mg/kg WIEO doses respectively. Overall, the results presented sustain and establish the anti-nociceptive and anti-inflammatory properties and justifies the need for further evaluation and development of the essential oils from this plant.

Este artículo informa por primera vez de compuestos volátiles, actividades anti-nociceptivas y antiinflamatorias de aceites esenciales de las hojas de Waltheria indica L. (Stericullaceae) que crecen en Nigeria. El aceite esencial fue hidro-destilado y se caracterizó por cromatografía de gases-detección de ionización de llama (GC-FID) y cromatografía de gases junto con análisis de espectrometría de masas (GC-MS). La actividad antiinflamatoria se evaluó en el edema de pata de rata inducido por carragenano, mientras que la prueba antinociceptiva se basó en el modelo de placa caliente. La destilación hidráulica proporcionó 0,41% (en peso seco) de aceite verde claro. Cuarenta compuestos que representan el 99.8% fueron identificados en el aceite. Los principales componentes del aceite fueron el limoneno (34,7%), el sabineno (21,2%) y el citronelal (9,7%). La propiedad anti-nociceptiva de los aceites esenciales inhibió estáticamente el desarrollo del edema (p<0.001) a una dosis de 200 y 400 mg/kg independientemente del tiempo de exposición. Sin embargo, los aceites esenciales de Waltheria indica de 100 mg/kg (WIEO) mostraron una inhibición relativamente baja (p<0.01-p>0.5) que disminuye a medida que aumenta el tiempo de exposición. Las actividades antiinflamatorias muestran una tasa constante y una actividad no dependiente de la dosis (p<0.001) hasta la tercera hora del estudio de inflamación. Por el contrario, una fuerte reducción a una tasa de p<0.5, 0.1 y 0.01 para las dosis de 100, 200 y 400 mg/kg de WIEO respectivamente. En general, los resultados presentados sostienen y establecen las propiedades anti-nociceptivas y antiinflamatorias y justifican la necesidad de una mayor evaluación y desarrollo de los aceites esenciales de esta planta.

Effect of meteorological elements on the content and composition of Aloysia triphylla (L´Hérit) Britton essential oil / Efecto de los elementos meteorológicos sobre el contenido y la composición del aceite esencial de Aloysia triphylla (L´Hérit) Britton

The concentration and composition of an essential oil can vary according to environmental variations and seasonal periods. The objective of this study was to correlate meteorological elements with the content and concentration of components of Aloysia triphylla essential oil, for the four seasons of the year. The experiment was conducted in a plastic greenhouse of the UFSM, Frederico Westphalen campus ­ RS, Brazil, in a complete randomized blocks design during the four seasons, with three repetitions. The meteorological data were collected with the aid of a compact meteorological station, in order to characterize the environment in which the species was conducted. The evaluations were carried out at the middle date of each season. It was observed a correlation between the meteorological variables with the essential oil production and its components. According to the analysis, there influence of the temperature on the essential oil contents, considering that the maximum temperature shows a direct positive influence on the concentration of limonene and negative for spathulenol.

El contenido y la composición de un aceite esencial pueden variar según las variaciones ambientales y los períodos estacionales. El objetivo de este estudio fue correlacionar los elementos meteorológicos con el contenido y la concentración de los componentes del aceite esencial de Aloysia triphylla, para las cuatro estaciones del año. El experimento se realizó en un invernadero de plástico de la UFSM, campus de Frederico Westphalen - RS, Brasil, en un diseño completo de bloques al azar durante las cuatro estaciones, con tres repeticiones. Los datos meteorológicos se recopilaron con la ayuda de una estación meteorológica compacta, para caracterizar el entorno en el que se realizó la especie. Las evaluaciones se llevaron a cabo en la fecha media de cada temporada. Se observó una correlación entre las variables meteorológicas con la producción de aceites esenciales y sus componentes. De acuerdo con el análisis, existe una influencia de la temperatura en los contenidos de aceites esenciales, considerando que la temperatura máxima muestra una influencia positiva directa sobre la concentración de limoneno y negativa para el espatulenol.

Seasonal chemical composition of an unexplored essential oil of Eugenia brevistyla / Composición química estacional de un aceite esencial no explorado de Eugenia brevistyla

This study describes the qualitative and quantitative seasonal analysis of the essential oils from an unexplored plant Eugenia brevistyla, native from Brazilian Atlantic Rain Forest and Semidecidual Forest. Analysis by GC-FID and GC-MS allowed the identification of 28 compounds. The largest fraction corresponds to oxygenated sesquiterpenes in all seasons. The major compound was E-nerolidol in all seasons, being higher in winter (83.14%) and lower in spring (69.6%). The second major compound was byciclogermacrene in the spring and in the summer essential oils. Alloaromadendrene and spathulenol were the second major compounds in autumn and winter, respectively. Sesquiterpenes hydrocarbons showed higher variation along the year (58%) than oxygenated sesquiterpenes (2%). No monoterpenes were found in the analyzed essential oils.

Este estudio describe el análisis estacional cualitativo y cuantitativo del aceite esencial de la planta inexplorada Eugenia brevistyla, nativa de la Selva Tropical Atlántica dey del Bosque Semidecidual de Brasil. El análisis por GC-FID y GC-MS permitió la identificación de 28 compuestos. La fracción más grande corresponde a sesquiterpenos oxigenados en todas las estaciones. El compuesto principal fue E-nerolidol en todas las estaciones, siendo más alto en invierno (83.14%) y más bajo en la primavera (69.6%). El segundo compuesto principal fue biciclogermacreno en los aceites esenciales de la primavera y del verano. El aloaromadendreno y el espatulenol fueron los segundos compuestos principales en otoño e invierno, respectivamente. Los hidrocarburos sesquiterpénicos mostraron una mayor variación a lo largo del año (58%) que los sesquiterpenos oxigenados (2%). No se encontraron monoterpenos en los aceites esenciales analizados.

Constituents of essential oils from the leaf, stem, root, fruit and flower of alpinia macroura k. schum / Constituyentes de los aceites esenciales de las hojas, tallo, raíz y flores de alpinia macroura k. schum

This paper reports the chemical constituents of essential oils from the various parts of Alpinia macroura K. Schum (Zingiberaceae) from Vietnam. The essential oils were obtained by hydrodistillation and analysed by means of gas chromatography coupled to Flame ionization detector (GC-FID) and gas chromatography coupled to mass spectrometry (GC/MS). The main constituents of the oils were beta-pinene (8.8 percent-16.4 percent), 1,8-cineole (5.5 percent-17.7 percent), upsilon-terpinene (5.9 percent-16.9 percent), alpha-pinene (4.5 percent-8.4 percent) and beta-caryophyllene (1.4 percent-18.6 percent). Sabinene (9.0 percent) was identified only in the fruit. Overall, nineteen of the identified compounds are coming to all the essential oils. The chemical constituents of essential oils from the leaf, stem, root, fruit and flower of A. macroura are being reported for the first time and were found to be different from those of other Alpinia oils.

En este trabajo se presentan los componentes químicos de los aceites esenciales de las distintas partes de Alpinia macroura K. Schum (Zingiberaceae) de Vietnam. Los aceites esenciales se obtuvieron por hidrodestilación y se analizaron por medio de cromatografía de gases acoplada a detector de ionización de llama (GC-FID) y cromatografía de gases acoplada a espectrometría de masas (GC/MS). Los principales constituyentes de los aceites fueron beta-pineno (8,8 por ciento -16,4 por ciento), 1,8-cineol (5,5 por ciento -17,7 por ciento), ípsilon-terpineno (5,9 por ciento -16,9 por ciento), alfa-pineno (4,5 por ciento -8,4 por ciento) y beta-cariofileno (1,4 por ciento -18,6 por ciento). Sabineno (9,0 por ciento) fue identificado solamente en la fruta. En general, diecinueve de los compuestos identificados están llegando a todos los aceites esenciales. Los componentes químicos de los aceites esenciales de la hoja, tallo, raíz, frutas y flores de A. macroura están siendo reportados por primera vez y se encontró que eran diferentes de las de otros aceites de Alpinia.

Urinary Trans, Trans-Muconic Acid is Not a Reliable Biomarker for Low-level Environmental and Occupational Benzene Exposures

BACKGROUND: Benzene is a known occupational and environmental pollutant. Its urinary metabolite trans, trans-muconic acid (tt-MA) has been introduced by some environmental and occupational health regulatory associations as a biological index for the assessment of benzene exposure; however, recently, doubts have been raised about the specificity of tt-MA for low-level benzene exposures. In the present study, we investigated the association between urinary levels of tt-MA and inhalational exposure to benzene in different exposure groups. METHODS: Benzene exposure was assessed by personal air sampling. Collected benzene on charcoal tube was extracted by carbon disulfide and determined by a gas chromatograph (gas chromatography with a flame ionization detector). Urinary tt-MA was extracted by a strong anion-exchange column and determined with high-performance liquid chromatography–UV. RESULTS: Urinary levels of tt-MA in intensive benzene exposure groups (chemical workers and police officers) were significantly higher than other groups (urban and rural residents), but its levels in the last two groups with significant different exposure levels (mean = 0.081 ppm and 0.019 ppm, respectively) showed no significant difference (mean = 388 μg/g creatinine and 282 μg/g, respectively; p < 0.05). Before work shift, urine samples of workers and police officers showed a high amount of tt-MA and its levels in rural residents’ samples were not zero. CONCLUSION: Our results suggest that tt-MA may not be a reliable biomarker for monitoring low-level (below 0.5 ppm) benzene exposures.

Composition of the essential oils from leaves of Piper lepturum Kunth (C.DC.) var. lepturum and Piper lepturum var. angustifolium (Miq.) Yunck. from Brasil / Composición de los aceites esenciales de hojas de Piper lepturum Kunth (C.DC.) var. lepturum y Pip

The essential oils of Brazilian Piper lepturum var. lepturum and Piper lepturum var. angustifolium (Piperaceae) were obtained by hydrodistillation and analyzed by flame-detector gas chromatography (GC) and gas chromatography coupled to mass spectrometry (GC/MS). According to GC and GC/MS analysis, the essential oils are mostly composed by sesquiterpenes hydrocarbons. beta-Guaiene (29.96 percent) was the principal component in the essential oil of P. lepturum var. lepturum and beta-Bisabolene (17.72 percent) was the principal components in the essential oil of P. lepturum var. angustifolium.

Los aceites esenciales de las especies brasileñas Piper lepturum var. lepturum y Piper lepturum var. angustifolium fueron obtenidos por hidrodestilación y analizados utilizando cromatografía gas líquido con detector de ionización de llama (CG) y cromatografía gas líquido acoplada a un detector de masas (CG/EM). De acuerdo con los análisis de CG y CG/EM, los aceites esenciales muestran como componente principal beta-Guaieno (29,96 por ciento) en el aceite esencial de P. lepturum var. lepturum y beta-Bisaboleno (17,71 por ciento) en el aceite esencial de P. lepturum var. angustifolium.

Seasonal variability of the essential oil of Hesperozygis ringens (Benth.) Epling. / Variabilidade sazonal do óleo essencial de Hesperozygis ringens (Benth.) Epling.

Abstract This study was developed to evaluate the effect of seasonality on the yield and chemical composition of the essential oil (EO) of Hesperozygis ringens (Benth.) Epling, a native species from the Brazilian Pampa. Leaves were collected from four specimens of a single population in each of the four seasons for a year and were extracted in triplicate by hydro-distillation for 2 hours. The yield of EO (% w/w) was calculated on fresh weight basis (FWB), and the 16 oil samples were analyzed by gas chromatography coupled to mass spectrometry (GC-MS) and gas chromatography with flame ionization detector (GC-FID). Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA) were used as statistical tools to evaluate differences in chemical composition. The highest yields were obtained in autumn, spring and summer (2.32-4.38%), while the lowest yields were detected in winter, ranging from 1.15 to 1.91%. Oxygenated monoterpenoids were the predominant class of chemical constituents in the EO obtained in all seasons, showing the highest contents in autumn and summer, and pulegone was identified as a major compound, whose contents varied between 54.13 and 81.17%. The EO samples were divided into three chemical groups by HCA and PCA and were assigned to the same group, except for the three samples gathered in winter. The results showed a seasonal influence on the yield and chemical composition of the EO.

Resumo Este estudo foi desenvolvido a fim de avaliar o efeito da sazonalidade no rendimento e composição química do óleo essencial (OE) de Hesperozygis ringens (Benth.) Epling., uma espécie nativa do Pampa brasileiro. Folhas foram coletadas de quatro indivíduos de uma mesma população, em cada uma das quatro estações de um ano, e foram extraídas em triplicada por hidrodestilação durante 2 horas. O rendimento do OE (% m/m) foi calculado considerando a base fresca (BF) e as 16 amostras de óleo foram analisadas por cromatografia gasosa acoplada à espectrometria de massas (CG-EM) e cromatografia gasosa com detector de ionização de chamas (CG-DIC). Análise Hierárquica de Cluster (AHC) e Análise de Componentes Principais (ACP) foram utilizadas como ferramentas estatísticas para avaliar as diferenças na composição química. Os maiores rendimentos foram obtidos no outono, primavera e verão (2,32-4,38%), enquanto que os menores foram detectados no inverno, variando de 1,15 até 1,91%. Os monoterpenoides oxigenados foram a classe predominante dos constituintes do OE obtido em todas as estações, apresentando os maiores teores no outono e no verão, e a pulegona foi identificada como o constituinte majoritário, cujos teores variaram entre 54,13 e 81,17%. As amostras de OE foram divididas em três grupos químicos por AHC e ACP e foram classificadas no mesmo grupo, com exceção de três amostras coletadas no inverno. Os resultados demonstraram influência sazonal no rendimento e na composição química dos OE.

Effect of (+)-dehydrofukinone on GABAA receptors and stress response in fish model

(+)-Dehydrofukinone (DHF) is a major component of the essential oil of Nectandra grandiflora (Lauraceae), and exerts a depressant effect on the central nervous system of fish. However, the neuronal mechanism underlying DHF action remains unknown. This study aimed to investigate the action of DHF on GABAA receptors using a silver catfish (Rhamdia quelen) model. Additionally, we investigated the effect of DHF exposure on stress-induced cortisol modulation. Chemical identification was performed using gas chromatography-mass spectrometry and purity was evaluated using gas chromatography with a flame ionization detector. To an aquarium, we applied between 2.5 and 50 mg/L DHF diluted in ethanol, in combination with 42.7 mg/L diazepam. DHF within the range of 10-20 mg/L acted collaboratively in combination with diazepam, but the sedative action of DHF was reversed by 3 mg/L flumazenil. Additionally, fish exposed for 24 h to 2.5-20 mg/L DHF showed no side effects and there was sustained sedation during the first 12 h of drug exposure with 10-20 mg/L DHF. DHF pretreatment did not increase plasma cortisol levels in fish subjected to a stress protocol. Moreover, the stress-induced cortisol peak was absent following pretreatment with 20 mg/L DHF. DHF proved to be a relatively safe sedative or anesthetic, which interacts with GABAergic and cortisol pathways in fish.

Exposure Characteristics of Construction Painters to Organic Solvents

BACKGROUND: Construction painters have not been studied well in terms of their hazards exposure. The objective of this study was to evaluate the exposure levels of total volatile organic compounds (TVOCs) for painters in the construction industry. METHODS: Activity-specific personal air samplings were carried out in three waterproofing activities [polyurethane (PU), asphalt, and cement mortar] and three painting activities (epoxy, oil based, and water based) by using organic-vapor-monitor passive-sampling devices. Gas chromatograph with flame ionization detector could be used for identifying and quantifying individual organic chemicals. The levels of TVOCs, by summing up 15 targeted substances, were expressed in exposure-index (EI) values. RESULTS: As arithmetic means in the order of concentration levels, the EIs of TVOCs in waterproofing works were 10.77, 2.42, 1.78, 1.68, 0.47, 0.07, and none detected (ND) for indoor PU-primer task, outdoor PU-primer task, outdoor PU-resin task, indoor PU-resin task, asphalt-primer task, asphalt-adhesive task, and cement-mortar task, respectively. The highest EI for painting works was 5.61 for indoor epoxy-primer task, followed by indoor epoxy-resin task (2.03), outdoor oil-based-spray-paint task (1.65), outdoor water-based-paint task (0.66), and indoor oil-based-paint task (0.15). Assuming that the operations were carried out continuously for 8 hours without breaks and by using the arithmetic means of EIs for each of the 12 tasks in this study, 58.3% (7 out of 12) exceeded the exposure limit of 100% (EI > 1.0), while 8.3% (1 out of 12) was in 50-100% of exposure limit (0.5 > EI > 1.0), and 4 tasks out of 12 were located in less than 50% of the limit range (EI < 0.5). CONCLUSION: From this study, we recognized that construction painters are exposed to various solvents, including carcinogens and reproductive toxins, and the levels of TVOC concentration in many of the painting tasks exceeded the exposure limits. Construction workers need to be protected from chemical agents during their painting works by using personal protective devices and/or work practice measures. Additional studies should focus on the exposure assessment of other hazards for construction workers, in order to identify high-risk tasks and to improve hazardous work environments.

Fatty Acid Content in Perilla Cultivars and Commercial Oils Determined by GC Analysis

The content analysis of fatty acids in Perilla cultivars and commercial oils is conducted through gas chromatography with a flame ionization detector. Results show that Perilla cultivars, such as Deulsaem and Daesil, contain high amounts of α-linolenic acid (262.22 and 261.97 mg/g, respectively). Among commercial oils, Perilla oil contains a higher amount of α-linolenic acid (515.20 mg/g). Accordingly, α-linolenic acid is a major fatty acid of Perilla cultivars and oil. Therefore, Perilla cultivars could be used as a food supplement for nutritional and pharmaceutical purposes.

Composition of essential oils from Euodia lepta (Spreng.) Merr and Euodia calophylla Guill., grown in Vietnam / Composición de los aceites esenciales de Euodia lepta (Spreng.) Merr y Euodia calophylla Guill., crecidas en Vietnam

The chemical compositions of essential oils obtained by hydrodistillation of the leaves, stems and flowers of Euodia lepta and Euodia callophylla grown in Vietnam and then analysed by gas chromatography-flame ionization detector (GC-FID) and gas chromatography/mass spectrometry (GC-MS) were being reported. The main compounds of the leaves oil of E. lepta were (E)-beta-ocimene (24.4 percent), alpha-pinene (9.8 percent), (Z)-beta-ocimene (6.3 percent) and delta-cadinene (5.2 percent), while the stems oil comprised of spathulenol (26.0 percent), (E)-beta- ocimene (9.9 percent) and (Z)-9-octadecenamide (7.7 percent). However, ciscarane (19.2 percent), alpha-cadinol (10.8 percent), alpha-pinene (10.5 percent) and (E)-beta-ocimene (9.0 percent) were present in the flowers oil of E. lepta. On the other hand, alpha-pinene (8.3 percent), trans-alpha-bergamotene (7.5 percent), (E)-beta-ocimene (7.0 percent) and (E)-nerolidol (6.6 percent) were the major constituents of the leaves oil of E. calophylla. The quantitatively significant compounds of the stems oil were (E,E)-alpha-farnesene (11.9 percent), alpha-terpinolene (11.3 percent) and alpha-pinene (8.2 percent), while alpha-pinene (21.6 percent), limonene (19.0 percent) and sabinene (15.5 percent) were obtained from the flowers oil...

La composición químicas de los aceites esenciales obtenidos por hidrodestilación de las hojas, tallos y flores de Euodia lepta y Euodia callophylla cultivadas en Vietnam, fueron analizados por cromatografía de gases-detector de ionización de llama (GC-FID) y la cromatografía de gases/espectrometría de masas (GC-MS). Los principales compuestos del aceite de hojas de E. lepta fueron (E) -beta-ocimeno (24,4 por ciento), alfa-pineno (9,8 por ciento), (Z)-beta- ocimeno (6,3 por ciento) y delta-cadineno (5.2 por ciento), mientras que los tallos de aceite estaban compuestos de spatulenol (26,0 por ciento), (E) -beta-ocimeno (9,9 por ciento) y (Z) -9- octadecenamida (7,7 por ciento). Sin embargo, cis-carano (19,2 por ciento), alfa-cadinol (10,8 por ciento), alfa-pineno (10,5 por ciento) y (E) -beta-ocimeno (9,0 por ciento) estaban presentes en el aceite de flores de E. lepta. Por otro lado, alfa-pineno (8,3 por ciento), trans-alfa-bergamoteno (7,5 por ciento), (E) - beta-ocimeno (7,0 por ciento) y (E) -nerolidol (6,6 por ciento) fueron los principales constituyentes del aceite de las hojas de E. calophylla. Los compuestos cuantitativamente significativos del aceite de los tallos fueron (E, E)-farneseno -alfa (11,9 por ciento), alfa-terpinoleno (11,3 por ciento) y alfa-pineno (8,2 por ciento), mientras que alfa-pineno (21,6 por ciento), limoneno (19,0 por ciento) y sabineno (15,5 por ciento) se obtuvieron del aceite de las flores...

Characterization of residual oils for biodiesel production

Background: Residual oils were characterized according to their physicochemical properties, i.e. acidity, iodine value, peroxide value and saponification number, to evaluate the degradation level and viability for biodiesel production. Results: The methyl esters of fatty acids (FAME) from samples of residual bovine, chicken and soybean oils were quantified by using four transesterification methods, using acidic and basic catalysis and, gas chromatography with flame ionization detector (GC-FID). Methods that used acidic catalysis at a lower temperature were the most efficient. Methyl biodiesel samples were synthesized by basic catalysis (KOH) for all quantified oils and the physicochemical properties of the biofuel were evaluated, i.e. viscosity, flash and fire points, density, water content, iodine and acidity numbers. Conclusions: The obtained results suggesting that it is possible to take advantage of these residues for biodiesel production as the obtained products were approved according to the rules established by the National Association of Petroleum (ANP); the bovine samples were the exception regarding moisture and acidity.

Determination of the content of residual solvents in Haikesu I by head-space gas chromatography / 中国医学科学院学报

<p><b>OBJECTIVE</b>To explore the usefulness of head-space gas chromatography for the determination of methanol and ethanol in Haikesu I,a raw material of artificial musk.</p><p><b>METHODS</b>The determination was performed on HP-5(30 m×0.53 mm,5 Μm)capillary column with an hydrogen flame ionization detector. The solvent was dimethyl sulfoxide and the internal standard was acetone. The injector temperature and the detector temperature were controlled at 180 ℃ and 250 ℃,respectively. The carrier gas was nitrogen. The containers of head-space injector were preheated at 90 ℃ for 15 minutes. The column temperature was programmed raised,which achieved baseline separation of the components.</p><p><b>RESULTS</b>The results showed a good linear relationship for methanol and ethanol in their linearity range;and the limit of detection was 0.8 and 1.0 Μg/ml,respectively. The precision and average recoveries were satisfactory.</p><p><b>CONCLUSION</b>The head-space gas chromatography is simple,rapid,and precise technique for the measurement of residual solvents in Haikesu I.</p>

Determination of the content of residual solvents in Haikesu 2 by head-space gas chromatography / 中国医学科学院学报

<p><b>OBJECTIVE</b>To determine ethylacetate and petroleum ether(60-90 ℃)in Haikesu 2,which is one of the raw materials of artificial musk,using the head-space gas chromatography.</p><p><b>METHODS</b>The determination was performed on HP-5(30 m×0.53 mm,5 Μm)capillary column with an hydrogen flame ionization detector. The solvent was dimethyl sulfoxide and the internal standard was methanol. The injector temperature and the detector temperature were controlled at 180 ℃ and 250 ℃,respectively. The carrier gas was nitrogen. The containers of head-space injector were preheated at 90 ℃ for 15 minutes. The column temperature was programmed raised,which achieved baseline separation of the components.</p><p><b>RESULTS</b>The results showed a good linear relationship for ethylacetate and petroleum ether(60-90 ℃)in their linearity range;and the limit of detection was 0.7 and 0.3 Μg/ml,respectively. The good precision and good average recoveries were satisfactory.</p><p><b>CONCLUSION</b>The head-space gas chromatography is simple,rapid,and precise technique for the measurement of residual solvents in Haikesu 2.</p>