Validación del uso tradicional de especies de Asclepias contra el veneno de Bothrops diporus (yarará chica) en el Nordeste de Argentina

La familia Asclepiadaceae posee tradición en etnomedicina. En el nordeste argentino, A.mellodora y A. curassavica se utilizan como cataplasmas en accidentes de ofidios. En este trabajo, los extractos acuosos, etanólicos y hexánicos de A. mellodora y A. curassavica se evaluaron por SDS-PAGE para determinar su actividad alexitérica. El estudio in vitro de la capacidad inhibitoria de las actividades proteolítica, hemolítica indirecta y coagulante permitieron determinar que ambas especies manifiestan actividad, siendo A. mellodora más activa. Estadísticamente los extractos de A. mellodora fueron igualmente activos contra el veneno de Bothrops diporus y no mostraron diferencias significativas respecto del órgano utilizado en la inhibición de la actividad coagulante. Este resultado está en consonancia con la forma tradicional de su uso como cataplasma. Sobre el extracto etanólico de las raíces de A. mellodora se realizó un fraccionamiento bioguiado que permitió identificar fracciones de compuestos responsables de la actividad

Determinación de marcadores de origen botánico para mieles de citrus (citrus spp) de la región fronteriza: Concordia (República Argentina) – Salto (República Oriental del Uruguay)

Argentina y Uruguay son productores de mieles de alta calidad que destinan en más de un 95% a exportación, especialmente a países de la CEE. Mercados exigentes que valorizan mieles diferenciadas por origen botánico y geográfico. La región fronteriza Concordia-Salto se caracteriza por ser una zona de producción citrícola, que cuenta con extensas plantaciones dedicadas a la producción de naranjas y mandarinas, lo que constituye una fuente de néctar para las colmenas instaladas en el área por apicultores de ambos países. La miel de cítricos es muy apreciada comercialmente con un valor agregado importante cuando es posible diferenciarla. Una de las dificultades que se presentan, es que debido a características propias la especie,  el número de gránulos de polen en la miel suele ser escaso, dificultando determinar origen botánico solo con este parámetro. El estudio complementario de las características físico-químicas y composición del aroma, resulta un aporte importante para diferenciar y valorizar estas mieles. El objetivo general de este proyecto es disponer en la región fronteriza Concordia-Salto de una miel tipificada de Citrus con el fin de aumentar su valor agregado y mejorar su posicionamiento en los mercados internacionales,  a partir de hallar componentes aromáticos marcadores de origen botánico

Odour-active compounds of Citrus deliciosa Tenore var. Caí essential oils detected by gas chromatography-mass spectrometry and gas chromatography-olfactometry

Context: Mandarins are a complex taxonomic group including different species, cultivars and hybrids growing around the world being fruits greatly appreciated by the consumers. Citrus deliciosa Tenore var. Caí originates from Rio Grande do Sul State (Brazil) and the fruit is characterised by its pleasant properties, especially its aroma. Aims: To evaluate the C. deliciosa cold-pressed essential oils, classified as “green”, “yellow” and “red” according to fruit maturity, and the one produced by distillation by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O). Methods: The essential oils aromatic quality was evaluated by GC-O through a panel of trained judges. The identification of the volatile compounds was performed by GC-MS and their quantification by GC-FID. Results: The chemical composition of the three types of cold-pressed essential oils was very similar. However, the distilled oil presented a higher concentration of oxygenated monoterpenes (mainly α-terpineol, 4-terpineol and sabinene hydrates). Herbaceous and floral aromatic notes were able to describe the “green” oil, while for the distilled oil wood and unpleasant notes were perceived. Conclusions: The cold-pressed oils did not show nor chemical, or aromatic differences, by the fruit maturity. The distilled oil was characterized by aromatic nuances making the oil less appreciated (inferior quality) than the cold-pressed oil. Probably as consequence of artifacts formation during the distillation process

<i>De Novo</i> Synthesis of Benzenoid Compounds by the Yeast <i>Hanseniaspora vineae</i> Increases the Flavor Diversity of Wines

Benzyl alcohol and other benzenoid-derived metabolites of particular importance in plants confer floral and fruity flavors to wines. Among the volatile aroma components in <i>Vitis vinifera</i> grape varieties, benzyl alcohol is present in its free and glycosylated forms. These compounds are considered to originate from grapes only and not from fermentative processes. We have found increased levels of benzyl alcohol in red Tannat wine compared to that in grape juice, suggesting <i>de novo</i> formation of this metabolite during vinification. In this work, we show that benzyl alcohol, benzaldehyde, <i>p</i>-hydroxybenzaldehyde, and <i>p</i>-hydroxybenzyl alcohol are synthesized <i>de novo</i> in the absence of grape-derived precursors by <i>Hanseniaspora vineae</i>. Levels of benzyl alcohol produced by 11 different <i>H. vineae</i> strains were 20–200 times higher than those measured in fermentations with <i>Saccharomyces cerevisiae</i> strains. These results show that <i>H. vineae</i> contributes to flavor diversity by increasing grape variety aroma concentration in a chemically defined medium. Feeding experiments with phenylalanine, tryptophan, tyrosine, <i>p</i>-aminobenzoic acid, and ammonium in an artificial medium were tested to evaluate the effect of these compounds either as precursors or as potential pathway regulators for the formation of benzenoid-derived aromas. Genomic analysis shows that the phenylalanine ammonia-lyase (<i>PAL</i>) and tyrosine ammonia lyase (<i>TAL</i>) pathways, used by plants to generate benzyl alcohols from aromatic amino acids, are absent in the <i>H. vineae</i> genome. Consequently, alternative pathways derived from chorismate with mandelate as an intermediate are discussed

Essential oils of Mentha pulegium and Mentha rotundifolia from Uruguay

Essential oils obtained by hydrodistillation from leaves of Mentha pulegium L. and Mentha rotundifolia (L.) Huds. from Uruguay were analysed by GC-FID and GC-MS. Oxygen-containing monoterpenes were the main group of constituents in both oils. Pulegone, isomenthone and menthone were the major components in the oil of M. pulegium, whereas piperitenone oxide and (Z)-sabinene hydrate were the major ones in M. rotundifolia. Enantiomerically pure (-)-menthone, (+)-isomenthone, (+)-isomenthol, (-)-menthol and (+)-pulegone were detected by multidimensional gas chromatography in the case of M. pulegium oil.<br>Óleos essenciais obtidos por hidrodestilação das folhas de Mentha pulegium L. e Mentha rotundifolia (L.) Huds. do Uruguay foram analisados por GC-FID e GC-MS. O grupo de monoterpenes oxigenados foi o mais importante em ambos os óleos, sendo que a pulegona, isomenthona e menthona foram os constituintes maioritarios no óleo de Mentha pulegium, no entanto, o ôxido de piperitenona e (Z)-hidrato de sabineno foram os maioritarios na Mentha rotundifolia. (-)-mentone, (+)-isomentone, (+)-isomenthol, (-)-menthol e (+)-pulegone enantioméricamente puras foram detectadas por cromatografía gasosa multidimensional no caso do óleo de Mentha pulegium