Chemical characterization of the essential oil from leaves of basil genotypes cultivated in different seasons / Caracterización química del aceite esencial de hojas genotipos de albahaca cultivados en diferentes estaciones del año

The aim of this study was to evaluate the concentration and chemical composition of the essential oil the leaves of basil cultivars and hybrids cultivated in different cropping seasons: dry season and rainy season. The variables evaluated were the content and composition of essential oils in the two seasons. The essential oil content ranged from 0.66% to 3.21% in the dry season and from 0.80% to 4.20% in the rainy season. The major compounds found among the genotypes were linalool, methyl chavicol, neral, geranial, eugenol, and methyl (E)- cinnamate, defining the formation of five groups in each season, classified in the following chemotypes: methyl chavicol (Group 1), citral (neral+geranial) (Group 2), methyl cinnamate (Group 3), linalool (Group 4), and intermediate linalool (Group 5). All the traits evaluated had heritability (h ) greater than 95% and high CVg/CVe ratio values. The cropping season affected the content and chemical compositions of basil essential oil.

El objetivo de este estudio fue evaluar la concentración y composición química del aceite esencial las hojas de cultivares de albahaca e híbridos cultivados en diferentes temporadas de cultivo: estación seca y estación lluviosa. Las variables evaluadas fueron la contenido y la composición de los aceites esenciales en las dos estaciones. La contenido de aceite esencial varió de 0.66% a 3.21% en la estación seca y de 0.80% a 4.20% en la estación lluviosa. Los principales compuestos encontrados entre los genotipos fueron linalool, metilchavicol, neral, geranial, eugenol y metil (E)-cinamato, definiendo la formación de cinco grupos en cada estación, clasificados en los siguientes quimiotipos: metil chavicol (Grupo 1), citral (neral + geranial) (Grupo 2), cinamato de metilo (Grupo 3), linalool (Grupo 4) y linalol intermedio (Grupo 5). Todos los rasgos evaluados mostraron una heredabilidad (h ) mayor que el 95% y altos valores de relación CVg/CVe. La temporada de cultivo afectó la contenido y las composiciones químicas del aceite esencial de albahaca.

Essential oil from leaves of Myrcianthes fragrans (Myrtaceae) from Costa Rica: a new chemotype? / Aceite esencial de las hojas de Myrcianthes fragrans (Myrtaceae) de Costa Rica: ¿Un nuevo quimiotipo?

Myrcianthes is a Myrtaceous genus of flowering plants of about 30 to 40 species, distributed in the American continent. The aim of this work was to study the chemical composition of the foliar essential oil from M. fragrans growing wild in central Costa Rica. The essential oil was obtained through the steam distillation process in a Clevenger type apparatus. The chemical composition of the oil was performed by capillary gas chromatography with a flame detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS) using the retention indices on a DB-5 type capillary column in addition to mass spectral fragmentation patterns. A total of 98 compounds were identified, accounting for 98.8% of the total amount of the oil. The major constituents in the leaf oil were (E)-methyl cinnamate (39.6%), limonene (34.6%), α-pinene (6.8%), and linalool (6.8%). This is the first report of (E)-methyl cinnamate occurring in oils of this plant genus. These findings appear to suggest a new chemotype of M. fragrans.

Myrcianthes (Myrtaceae) consta de 30 a 40 especies, distribuidas en el continente americano. El objetivo del presente trabajo consistió en identificar la composición química del aceite esencial contenido en las hojas de M. fragrans, planta que crece en forma silvestre en el Valle Central de Costa Rica. La extracción del aceite se efectuó mediante el método de hidrodestilación usando un equipo de Clevenger modificado. La composición química del aceite se analizó mediante las técnicas de cromatografía gaseoso-líquida con detector de ionización de llama (GC-FID) y de cromatografía gaseoso-líquida acoplada a un detector de masas (GC-MS). Se utilizaron índices de retención obtenidos en una columna capilar tipo DB-5 y se compararon con los patrones de iones de fragmentación de masas. Se identificaron en total 98 compuestos, correspondientes a un 98.8% de los constituyentes totales. Los componentes mayoritarios del aceite resultaron ser (E)-cinamato de metilo (39.6%), limoneno (34.6%), α-pineno (6.8%) y linalol (6.8%). Este es el primer informe de la aparición de (E)-cinamato de metilo en aceite de hojas de este género de plantas. Los datos obtenidos parecen sugerir un nuevo quimiotipo de M. fragrans.

Antibacterial potential of non-volatile constituents of Rosmarinus officinalis against 37 clinical isolates of multidrug-resistant bacteria / Actividad antibacteriana de constituyentes no volátiles de Rosmarinus officinalis contra 37 aislamientos clínicos de bacterias multirresistentes

In this paper we investigated the antibacterial activity of a methanolic extract of Rosmarinus officinalis L. and their main constituents, carnosic acid and rosmarinic acid, against 37 nosocomial strains of multidrug-resistant bacteria. Results obtained showed that both the rosemary extract and carnosic acid inhibited all clinical isolates of Staphylococcus aureus methicillin-resistant and Enterococcus faecalis gentamicin and streptomycin-resistant bacteria examined (MICs 60 ug/mL vs. 200 ug/mL, respectively). Rosemary extract showed MIC values between 400 and 1600 ug/ml against the Gram-negative multidrug-resistant bacteria: Escherichia coli, Proteus mirabilis, Enterobacter cloacae, Pseudomonas aeruginosa, Morganella morganii and Providencia stuartii, while carnosic acid showed MIC of 120 to 240 ug/mL. Bactericidal effect of carnosic acid against S. aureus and E. faecalis was observed at their MIC value, while 2 x MIC to 4 x MIC were needed to kill Gram-negative bacteria. Rosmarinic acid showed a narrow spectrum of action against a few Gram-negative clinical isolates. Our findings suggest that carnosic acid would be a good lead candidate useful in counteracting drug-resistant infections.

En este trabajo evaluamos la actividad antibacteriana de un extracto metanólico de Rosmarinus officinalis L. y sus principales componentes el ácido carnósico y ácido rosmarínico, contra 37 cepas de bacterias multirresistentes nosocomiales. Los resultados muestran que el extracto de romero y el ácido carnósico, inhibieron las bacterias Gram-positivas Staphylococcus aureus resistentes a meticilina y Enterococcus faecalis resistentes a gentamicina y estreptomicina (CIM 200 ug/mL y 60 ug/mL, respectivamente). El extracto de romero inhibió los Gram negativos multirresistentes: Escherichia coli, Proteus mirabilis, Enterobacter cloacae, Pseudomonas aeruginosa, Morganella morganii y Providencia stuartii (CIM 400 a 1600 ug/mL), mientras que el ácido carnósico mostró valores de CIM entre 120 a 240 ug/mL. El ácido carnósico mostró actividad bactericida contra S. aureus y E. faecalis a su CIM, mientras que 2 a 4 X CIM se requirieron para matar las bacterias Gram-negativas. El ácido rosmarínico mostró inhibió unos pocos aislados clínicos Gram-negativos. Estos hallazgos sugieren que el ácido carnósico puede ser de utilidad contra infecciones bacterianas multirresistentes a antibióticos.

Variation in concentrations of major bioactive compounds in Prunella vulgaris L. related to plant parts and phenological stages

Prunella vulgaris L. (Labiatae) contains a variety of structurally diverse natural products, primarily rosmarinic acid (RA), ursolic acid (UA) and oleanolic acid (OA), which possess a wide array of biological properties. In the present study, P. vulgaris was harvested at three developmental stages (vegetative, full-flowering and mature-fruiting stages), dissected into stem and leaf tissues and assayed for chemical contents using high performance liquid chromatography. Significant changes in the concentrations of the major secondary metabolites (RA, UA and OA) were observed at the different development stages. The highest concentrations of RA, UA and OA were found at the full-flowering stage (15.83 mg/g dry weight (DW) RA, 1.77 mg/g DW UA and 0.65 mg/g DW OA). Among the different aerial parts of the plant, the concentrations of RA, UA and OA were higher in the leaves than in the stems at the different developmental stages. These results suggest that the full-flowering stage is characterized by the highest concentrations of bioactive compounds. Therefore, this stage may be the optimum point for harvesting P. vulgaris plants. In additional, the leaves of P. vulgaris demonstrated higher RA, UA and OA concentrations than the stems, suggesting higher utilization potential.

Trans-isoferulic acid from Curcuma longa / Ácido trans-isoferulico en Curcuma Longa

Trans-isoferulic acid was isolated from the carbon tetrachloride soluble fraction of a methanol extract of the rhizomes of Curcuma longa (Zingiberaceae). The structure of the isolated compound was elucidated by comprehensive analysis of spectroscopic data. This is the first report of its occurrence from this plant.

El ácido trans-isoferulico fue aislado de la fracción soluble en tetracloruro de carbono del extracto metanólico de los rizomas de Curcuma Longa (Zingeraceae). La estructura del compuesto aislado fue elucidada por análisis de los datos espectroscópicos. Este es el primer reporte de su presencia en esta planta.

Role of phenolics and boron in reproductive success in seasonally transient sterile Tecoma stans L.

Quantitative and qualitative analysis of phenolics and boron in stigma of transient sterile Tecoma stans L. during seedless (May-July), partially seedbearing (August-November, April) and seedbearing periods (December-March) was made. UV absorption profile of stigmatic exudates indicated the presence of simple phenolics. Total phenolics were higher in stigma during seedless period. Thin layer chromatographic analysis of stigmatic extracts exhibited only three principal spots. Mass spectrophotometry showed the presence of derivatives of cinnamic acid, namely, caffeic acid in these spots. Quantity of boron in stigma during seedless period was lowest but the difference with other periods was not significant. It was suggested that the accumulation of higher quantity of caffeic acid in the stigma during seedless period due to high temperature (40 degrees-45 degrees C) could lead to inhibition of pollen germination in vivo, thereby rendering the plants seedless. This was confirmed by inhibition of in vitro pollen germination in the basal medium containing higher quantity of caffeic acid.