Browsing by Author "Escuredo, Olga"
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- Assessment of the in vivo and in vitro release of chemical compounds from vespa velutinaPublication . Rodriguez-Flores, Maria Shantal; Falcão, Soraia; Escuredo, Olga; Queijo, Luis; Seijo-Coello, M. Carmen; Vilas-Boas, MiguelVespa velutina has been rapidly expanding throughout Galicia since 2012. It is causing human health risks and well-known losses in the beekeeping sector. Control methods are scarce, unspecific, and ineffective. Semiochemicals are insect-derived chemicals that play a role in communication and they could be used an integrated pest management tool alternative to conventional pesticides. A previous determination of the organic chemical profile should be the first step in the study of these semiochemicals. HS-SPME in living individuals and the sting apparatus extraction followed by GC-MS spectrometry were combined to extract a possible profile of these compounds in 43 hornets from Galicia. The identified compounds were hydrocarbons, ketones, terpenes, and fatty acid, and fatty acid esters. Nonanal aldehyde appeared in important concentrations in living individuals. While pentadecane, 8-hexyl-and ethyl oleate were mainly extracted from the venom apparatus. Ketones 2-nonanone, 2-undecanone and 7-nonen-2-one, 4,8-dimethyl-were identified by both procedures, as was 1,7-Nonadiene, 4,8-dimethyl-. Some compounds were detected for the first time in V. velutina such as naphthalene, 1,6-dimethyl-4-(1-methylethyl). The chemical profile by caste was also characterized.
- Chemical profile from the head of Vespa velutina and V. crabroPublication . Rodriguez-Flores, Maria Shantal; Falcão, Soraia; Escuredo, Olga; Seijo-Coello, M. Carmen; Vilas-Boas, MiguelVespa velutina and V. crabro are eusocial insects in which chemical communication is decisive for social interactions. V. velutina was accidentally introduced in 2004 in France and subsequently in northern Spain in 2010. It is an invasive species that severely affects the beekeeping sector. The hornet autochthonous V. crabro with a similar ecological niche is captured in bait traps used to control V. velutina populations. Insect cuticle and head structures had an important role in chemical communication so that this research approaches for the first time chemical compounds extracted from the heads of V. velutina and V. crabro. Chemical compounds were profiled using GC/MS. The main compounds identified were carbohydrates, fatty acids, and hydrocarbons. The chemical profile of both species was compared and also an intrinsic differentiation was made between queens and workers in V. velutina. Chemometric techniques (PCA and LSD) were used to achieve this goal.
- Description of the volatile fraction of Erica honey from the northwest of the Iberian PeninsulaPublication . Rodriguez-Flores, Maria Shantal; Falcão, Soraia; Escuredo, Olga; Seijo-Coello, M. Carmen; Vilas-Boas, MiguelHeather honey is highly appreciated by consumers for its sensorial profile, which varies depending on the flora used by the honeybees. Volatile compounds contribute to these qualities. Characterisation of the volatile profile related to the botanical origin is of great interest for the standardization of unifloral honey. For this reason, 33 heather honey samples from northwest of the Iberian Peninsula were analysed by headspace solid-phase microextraction (HS-SPME) to identify the key volatile compounds in this type of honey. The aim of this research was to provide a descriptive analysis of these compounds, and to find whether there is any relationship with the main Erica species. A total of 58 volatile organic compounds were found, with hotrienol, phenylacetaldehyde, and cis-linalool being the most abundant. A principal component analysis and Spearman's rank correlation showed the homogeneity of the volatile profile in the samples, and their close relationship with the main pollen types.
- Feromonas de Vespa Velutina. Estudio de sus compuestos volátiles orgánicosPublication . Rodriguez-Flores, Maria Shantal; Falcão, Soraia; Vilas-Boas, Miguel; Seijo-Coello, M. Carmen; Seijo Rodríguez, Ana; Escuredo, OlgaLa especie invasora, Vespa velutina, presenta una excelente adaptación a las condiciones climáticas del norte y noroeste de la Península Ibérica. Este factor, junto a la inexistencia de competidores naturales, ha favorecido su rápida expansión en esta región [1]. Los impactos socio-económicos causados son preocupantes, especialmente aquellos relacionados con el medio ambiente, ya que esta especie está perjudicando la diversidad entomológica, al provocar un descenso en las poblaciones de las especies de las que se alimenta, entre estas, destaca Apis mellifera. La acción sobre las abejas puede exterminar colmenas enteras afectando notablemente a la producción apícola. Uno de los métodos de control utilizados es el trampeo de las reinas fundadoras en primavera. Sin embargo, el trampeo es poco selectivo ya que actualmente no existe un atrayente específico que permita la captura exclusiva del avispón. V. velutina es una especie social, por lo que las feromonas, juegan un papel crucial en su comunicación [2]. Así el estudio de sus feromonas puede resultar interesante para la elaboración de un atrayente específico. De este modo, el principal objetivo de este estudio, se basa en la identificación de compuestos volátiles orgánicos (VOCs) presentes en individuos vivos y en feromonas procedentes de las glándulas de alarma. Los avispones se obtuvieron de una población natural con altas densidades de nidos en un colmenar de (A Cañiza, Pontevedra). El análisis GC-MS se realizó con un sistema Perkin Elmer con un módulo Clarus® 580 GC y un Clarus® SQ 8 S (Waltham, Massachusetts, USA). Se inyectaron muestras de feromonas recolectadas in vivo mediante un dispositivo SPME e in vitro mediante la extracción de las glándulas de alarma. Como principales resultados en los especímenes de velutina analizados in vivo, destacó el nonanal como uno de los compuestos con mayores concentraciones. Otros compuestos, destacables fueron el tetradecano, 4,6- dimethyldodecano, decanal, 4,7- dimethylundecano, y 9-hexylheptadecano. En cuanto a los extractos de las glándulas de alarma, los principales compuestos identificados fueron el tetracosano, heneicosano, eicosano, octacosanol, heptacosano, octacosano e sus derivados. La identificación de los compuestos presentes en las muestras junto al estudio de un mayor número de individuos de otras poblaciones puede ser de interés para desarrollar atrayentes específicos que mejoren el control de la especie.
- Phenolic profile of Castanea bee pollen from the northwest of the iberian peninsulaPublication . Rodriguez-Flores, Maria Shantal; Escuredo, Olga; Seijo-Coello, M. Carmen; Rojo, Sergio; Vilas-Boas, Miguel; Falcão, SoraiaBee pollen is a rich bee product, from the point of view of its nutritional and functional chemical characteristics. The chemical composition of bee pollen and its properties make this product an excellent food supplement for the human diet, due to its various functional bioactivities, such as having antioxidant, antibacterial, antifungal, and anti-inflammatory properties. These properties depend on the botanical origin of the bee pollen. Castanea sativa bee pollen is one of the most important types of pollen collected in the northwest of the Iberian Peninsula. Thus, the phenolic profile of Castanea bee pollen was featured in this study. For this, 11 samples of Castanea were selected through prior colorimetric separation using the CIELab* scale and verified with palynological analysis. Identification of the main phenol compounds was performed through LC/DAD/ESI-MSn analysis. The phenols compounds were quantified using calibration curves for caffeic acid, quercetin, and naringenin. The main results showed a profile formed of 19 compounds for all samples, although quantitative differences were found. Most of these compounds were phenolamides, with N-1, N-5, and N-10-tricaffeoylspermidine being significantly (p < 0.05) the most abundant. Three isorhamnetin glycoside derivatives and one naringenin were also identified. The richness in phenolamides of Castanea bee pollen identified in this study suggests Castanea bee pollen as a functional food, owing to its healthy properties.