Impact of genus (Geotrigona, Melipona, Scaptotrigona) in the targeted 1H-NMR organic profile, and authenticity test by interphase emulsion of honey processed in cerumen pots by stingless bees in Ecuador.

The biodiversity of Ecuadorian stingless bees is almost 200 species. Traditional pot-honey harvest in Ecuador is mostly done from nests of the three genera selected here Geotrigona Moure, 1943, Melipona Illiger, 1806, and Scaptotrigona Moure, 1942. The 20 pot-honey samples collected from cerumen pots and three ethnic honeys "abeja de tierra", "bermejo", and "cushillomishki" were analyzed for qualitative and quantitative targeted 1H-NMR honey profiling, and for the Honey Authenticity Test by Interphase Emulsion (HATIE). Extensive data of targeted organic compounds (41 parameters) were identified, quantified, and described. The three honey types were compared by ANOVA. Amino acids, ethanol, hydroxymethylfurfural, aliphatic organic acids, sugars, and markers of botanical origin. The number of phases observed with the HATIE were one in Scaptotrigona and three in Geotrigona and Melipona honeys. Acetic acid (19.60 ± 1.45 g/kg) and lactic acid (24.30 ± 1.65 g/kg) were particularly high in Geotrigona honey (in contrast to 1.3 g/kg acetic acid and 1.6 g/kg lactic acid in Melipona and Scaptotrigona), and with the lowest fructose + glucose (18.39 ± 1.68) g/100g honey compared to Melipona (52.87 ± 1.75) and Scaptotrigona (52.17 ± 0.60). Three local honeys were tested using PCA (Principal Component Analysis), two were assigned with a correct declared bee origin, but "bermejo" was not a Melipona and grouped with the Scaptotrigona cluster. However after HCA (Hierarchical Cluster Analysis) the three honeys were positioned in the Melipona-Scaptotrigona cluster. This research supports targeted 1H-NMR-based profiling of pot-honey metabolomics approach for multi-parameter visualization of organic compounds, as well as descriptive and pertained multivariate statistics (HCA and PCA) to discriminate the stingless bee genus in a set of Geotrigona, Melipona and Scaptotrigona honey types. The NMR characterization of Ecuadorian honey produced by stingless bees emphasizes the need for regulatory norms. A final note on stingless bee markers in pot-honey metabolites which should be screened for those that may extract phylogenetic signals from nutritional traits of honey. Scaptotrigona vitorum honey revealed biosurfactant activity in the HATIE, originating a fingerprint Honey Biosurfactant Test (HBT) for the genus in this set of pot-honeys.

Chemical composition of the essential oil from the leaves of Carapa guianensis collected from Venezuelan Guayana and the antimicrobial activity of the oil and crude extracts.

The essential oil obtained by hydrodistillation of Carapa guianensis Aubl. (Meliaceae) leaves was analyzed by GC-FID and GC-MS. Twenty-three components were identified, which made up 93.7% of the oil. The most abundant constituents were bicyclogermacrene (28.5%), alpha-humulene (17.2%), germacrene B (11.9%), and trans-beta-caryophyllene (9.9%). Antimicrobial activity of the essential oil, as well as the crude extracts of the leaves obtained by refluxing the dried leaves with n-hexane, dichloromethane, and methanol, was determined using the disc diffusion assay. Activity against Staphylococcus aureus ATCC 29923 and Enterococcus faecalis ATCC 29212 was only found for the essential oil and the methanolic extract, at minimal inhibitory concentrations (MIC) of 400 microg/mL and 50 microg/mL.

Presencia de ácido láctico y otros compuestos semivolátiles en mieles de meliponini / Presence of lactic acid and other semivolatil compound in meliponini honeys

Durante el estudio de compuestos semivolátiles, se encontró ácido láctico en mieles producidas por cuatro especies de abejas sin aguijón. Además, se identificaron otros compuestos: ácido 2-etil-2-hidroxi-propanoico en mieles de Melipona favosa, 5-(hidroximetil)-2-furancarboxaldehído y a-(fenilmetil)-benceno etanol, en mieles de Scaptotrigona mexicana, 2-butanol, eneicosano y heptacosano en mieles deTrigona carbonaria.

During the study of semivolatile compounds, lactic acid was found in the honey produced by four species of stingless bees. Moreover, other compounds were identified: 2-ethylhydroxy- propanoic acid in Melipona favosa honeys, 5-(hydroxymethyl)-2-furancarboxaldehyde and a-phenylmethyl benzene ethanol in Scaptotrigona mexicana honey, 2-butanol, heneicosane and heptacosane in Trigona carbonaria honey.

Chemical composition and antibacterial activity of the essential oil of Cordia verbenacea from the Venezuelan Andes.

The essential oil of Cordia verbenacea D.C. (Boraginaceae) that grows in Mérida-Venezuela was obtained by hydrodistillation from the aerial parts of the plant, yielding 0.21%. The oil was analyzed by GC-FID and GC-MS. Thirty one components which made up 94.3% of the oil were identified. The most abundant constituents found were: tricyclene (23.9%), bicyclogermacrene (11.7%), germacrene D (9.9%) and beta-caryophyllene (8.2%). Antibacterial activity determination was carried out according to the disc diffusion assay. Activity against Gram-positive bacteria Staphylococcus aureus ATCC 6538 and Enterococcus faecalis ATCC 29212, at a minimal inhibitory concentration (MIC) of 170 microg/mL and 200 microg/mL, was found.

Estudio comparativo de los aceites esenciales de Callistemon speciosus DC: recolectado en los estados Carabobo, Lara y Mérida (Venezuela) / Study comparative oils of Callistemon speciosus DC: from Carabobo Lara and Mérida states (Venezuela)

Los aceites esenciales de callistemon speciosus DC; de los estados Carabobo, Lara y Mérida fueron extraídos por hidrodestilación y analizados por cromatografía de gases acoplada a espectrometría de masas (CG-EM). Se encontró como constituyente más abundante al 1,8-cineol, mostrando el aceite del estado Lara el mayor contenido del mismo (71,05 por ciento). El aceite de Carabobo contiene 68,56 por ciento de 1,8-cineol y el de Mérida solo 43,31 por ciento. El callistemon speciosus de Mérida produce el más bajo rendimiento de aceite (0.46 por ciento), mientras que las plantas de Lara (0,86 por ciento) y Carabobo (0,92 por ciento) tienen mayor rendimiento de aceite

Análisis de los componentes mayoritarios del aceite esencial del ocimum gratissimum L / Analysis of the majority components of the esential oil ocimum gratissimum L

El Ocimum gratissimum L., es comúnmente conocido como albahaca y pertenece a la familia Lamiaceae. Las partes aéreas fueron recolectadas del Jardín de Plantas Medicinales "Dr. Luis Ruis Terán" de la Facultad de Farmacia de la Universidad de Los Andes. La planta fue hidrodestilada por 3 horas en un aparato de Clevenger, dando un aceite con un rendimiento de 0,4 por ciento. El aceite fue analizado por cromatografía de gases y Cromatografía de Gases acoplada a Espectrometría de Masas. Los componentes mayoritarios encontrados en el aceite fueron: alfa-tujeno (2,46 por ciento de abundancia relativa), alfa-pineno (0,70 por ciento), ß-mirceno (2,95 por ciento), alfa-terpineno (2,69 por ciento), p-cimeno (5,21), gamma-terpineno (19,40 por ciento) y timol (50,37 por ciento)