Volatiles and Nonvolatiles in Flourensia campestris Griseb. (Asteraceae), How Much Do Capitate Glandular Trichomes Matter?

The distribution and ultrastructure of capitate glandular trichomes (GTs) in Flourensia species (Asteraceae) have been recently elucidated, but their metabolic activity and potential biological function remain unexplored. Selective nonvolatile metabolites from isolated GTs were strikingly similar to those found on leaf surfaces. The phytotoxic allelochemical sesquiterpene (-)-hamanasic acid A ((-)-HAA) was the major constituent (ca. 40%) in GTs. Although GTs are quaternary ammonium compounds (QACs)-accumulating species, glycine betaine was not found in GTs; it was only present in the leaf mesophyll. Two (-)-HAA accompanying surface secreted products: compounds 4-hydroxyacetophenone (piceol; 1) and 2-hydroxy-5-methoxyacetophenone (2), which were isolated and fully characterized (GC/MS, NMR), were present in the volatiles found in GTs. The essential oils of fresh leaves revealed ca. 33% monoterpenes, 26% hydrocarbon- and 30% oxygenated sesquiterpenes, most of them related to cadinene and bisabolene derivatives. Present results suggest a main role of GTs in determining the volatile and nonvolatile composition of F. campestris leaves. Based on the known activities of the compounds identified, it can be suggested that GTs in F. campestris would play key ecological functions in plant-pathogen and plant-plant interactions. In addition, the strikingly high contribution of compounds derived from cadinene and bisabolene pathways, highlights the potential of this species as a source of high-valued bioproducts.

Resolution of deep nodes yields an improved backbone phylogeny and a new basal lineage to study early evolution of Asteraceae.

A backbone phylogeny that fully resolves all subfamily and deeper nodes of Asteraceae was constructed using 14 chloroplast DNA loci. The recently named genus Famatinanthus was found to be sister to the Mutisioideae-Asteroideae clade that represents more than 99% of Asteraceae and was found to have the two chloroplast inversions present in all Asteraceae except the nine genera of Barnadesioideae. A monotypic subfamily Famatinanthoideae and tribe Famatinantheae are named herein as new. Relationships among the basal lineages of the family were resolved with strong support in the Bayesian analysis as (Barnadesioideae (Famatinanthoideae (Mutisioideae (Stifftioideae (Wunderlichioideae-Asteroideae))))). Ancestral state reconstruction of ten morphological characters at the root node of the Asteraceae showed that the ancestral sunflower would have had a woody habit, alternate leaves, solitary capitulescences, epaleate receptacles, smooth styles, smooth to microechinate pollen surface sculpturing, white to yellow corollas, and insect-mediated pollination. Herbaceous habit, echinate pollen surface, pubescent styles, and cymose capitulescences were reconstructed for backbone nodes of the phylogeny corresponding to clades that evolved shortly after Asteraceae dispersed out of South America. No support was found for discoid capitula, multiseriate involucres or bird pollination as the ancestral character condition for any node. Using this more resolved phylogenetic tree, the recently described Raiguenrayun cura+Mutisiapollis telleriae fossil should be associated to a more derived node than previously suggested when time calibrating phylogenies of Asteraceae.

NeuroEditor: a tool to edit and visualize neuronal morphologies.

The digital extraction of detailed neuronal morphologies from microscopy data is an essential step in the study of neurons. Ever since Cajal's work, the acquisition and analysis of neuron anatomy has yielded invaluable insight into the nervous system, which has led to our present understanding of many structural and functional aspects of the brain and the nervous system, well beyond the anatomical perspective. Obtaining detailed anatomical data, though, is not a simple task. Despite recent progress, acquiring neuron details still involves using labor-intensive, error prone methods that facilitate the introduction of inaccuracies and mistakes. In consequence, getting reliable morphological tracings usually needs the completion of post-processing steps that require user intervention to ensure the extracted data accuracy. Within this framework, this paper presents NeuroEditor, a new software tool for visualization, editing and correction of previously reconstructed neuronal tracings. This tool has been developed specifically for alleviating the burden associated with the acquisition of detailed morphologies. NeuroEditor offers a set of algorithms that can automatically detect the presence of potential errors in tracings. The tool facilitates users to explore an error with a simple mouse click so that it can be corrected manually or, where applicable, automatically. In some cases, this tool can also propose a set of actions to automatically correct a particular type of error. Additionally, this tool allows users to visualize and compare the original and modified tracings, also providing a 3D mesh that approximates the neuronal membrane. The approximation of this mesh is computed and recomputed on-the-fly, reflecting any instantaneous changes during the tracing process. Moreover, NeuroEditor can be easily extended by users, who can program their own algorithms in Python and run them within the tool. Last, this paper includes an example showing how users can easily define a customized workflow by applying a sequence of editing operations. The edited morphology can then be stored, together with the corresponding 3D mesh that approximates the neuronal membrane.

Global sampling of plant roots expands the described molecular diversity of arbuscular mycorrhizal fungi.

We aimed to enhance understanding of the molecular diversity of arbuscular mycorrhizal fungi (AMF) by building a new global dataset targeting previously unstudied geographical areas. In total, we sampled 96 plant species from 25 sites that encompassed all continents except Antarctica. AMF in plant roots were detected by sequencing the nuclear SSU rRNA gene fragment using either cloning followed by Sanger sequencing or 454-sequencing. A total of 204 AMF phylogroups (virtual taxa, VT) were recorded, increasing the described number of Glomeromycota VT from 308 to 341 globally. Novel VT were detected from 21 sites; three novel but nevertheless widespread VT (Glomus spp. MO-G52, MO-G53, MO-G57) were recorded from six continents. The largest increases in regional VT number were recorded in previously little-studied Oceania and in the boreal and polar climatic zones - this study providing the first molecular data from the latter. Ordination revealed differences in AM fungal communities between different continents and climatic zones, suggesting that both biogeographic history and environmental conditions underlie the global variation of those communities. Our results show that a considerable proportion of Glomeromycota diversity has been recorded in many regions, though further large increases in richness can be expected in remaining unstudied areas.

Arbuscular Mycorrhizal Fungal Communities in the Soils of Desert Habitats.

Deserts cover a significant proportion of the Earth's surface and continue to expand as a consequence of climate change. Mutualistic arbuscular mycorrhizal (AM) fungi are functionally important plant root symbionts, and may be particularly important in drought stressed systems such as deserts. Here we provide a first molecular characterization of the AM fungi occurring in several desert ecosystems worldwide. We sequenced AM fungal DNA from soil samples collected from deserts in six different regions of the globe using the primer pair WANDA-AML2 with Illumina MiSeq. We recorded altogether 50 AM fungal phylotypes. Glomeraceae was the most common family, while Claroideoglomeraceae, Diversisporaceae and Acaulosporaceae were represented with lower frequency and abundance. The most diverse site, with 35 virtual taxa (VT), was in the Israeli Negev desert. Sites representing harsh conditions yielded relatively few reads and low richness estimates, for example, a Saudi Arabian desert site where only three Diversispora VT were recorded. The AM fungal taxa recorded in the desert soils are mostly geographically and ecologically widespread. However, in four sites out of six, communities comprised more desert-affiliated taxa (according to the MaarjAM database) than expected at random. AM fungal VT present in samples were phylogenetically clustered compared with the global taxon pool, suggesting that nonrandom assembly processes, notably habitat filtering, may have shaped desert fungal assemblages.

The Morelloid clade of Solanum L. (Solanaceae) in Argentina: nomenclatural changes, three new species and an updated key to all taxa.

Since the publication of the Solanaceae treatment in "Flora Argentina" in 2013 exploration in the country and resolution of outstanding nomenclatural and circumscription issues has resulted in a number of changes to the species of the Morelloid clade of Solanum L. (Solanaceae) for Argentina. Here we describe three new species: Solanum hunzikeri Chiarini & Cantero, sp. nov., from wet high elevation areas in Argentina (Catamarca, Salta and Tucumán) and Bolivia (Chuquisaca and Tarija), S. marmoratum Barboza & S. Knapp, sp. nov., from central Argentina in Catamarca, La Pampa, La Rioja, San Juan and San Luis, and S. tiinae Barboza & S. Knapp, sp. nov., from the mountains of Jujuy, La Rioja, Salta and Tucumán. We provide descriptions, illustrations and distribution maps for all new taxa. A table of nomenclatural changes and additional taxa now known to occur in Argentina summarizes additions and changes since the "Flora Argentina". We also provide an updated key, including all new taxa for the country, to facilitate identification and further exploration.

Screening of Argentinian plants for pesticide activity.

Aerial parts of 27 plant species native to Argentina were tested in anti-insect, germination inhibition and bactericide bio-assays. In antifeedant assays on Epilachna paenulata larvae, 11 species showed strong feeding deterrent effects (higher than 90% at 200 microg/cm(2)). Twelve plants strongly inhibited the germination of Avena sativa seeds, but only six inhibited Raphanus sativum germination at 10 mg/ml. Four plants showed complete growth inhibition of Escherichia coli at a concentration of 2 mg/ml.

NeuroTessMesh: A Tool for the Generation and Visualization of Neuron Meshes and Adaptive On-the-Fly Refinement.

Gaining a better understanding of the human brain continues to be one of the greatest challenges for science, largely because of the overwhelming complexity of the brain and the difficulty of analyzing the features and behavior of dense neural networks. Regarding analysis, 3D visualization has proven to be a useful tool for the evaluation of complex systems. However, the large number of neurons in non-trivial circuits, together with their intricate geometry, makes the visualization of a neuronal scenario an extremely challenging computational problem. Previous work in this area dealt with the generation of 3D polygonal meshes that approximated the cells' overall anatomy but did not attempt to deal with the extremely high storage and computational cost required to manage a complex scene. This paper presents NeuroTessMesh, a tool specifically designed to cope with many of the problems associated with the visualization of neural circuits that are comprised of large numbers of cells. In addition, this method facilitates the recovery and visualization of the 3D geometry of cells included in databases, such as NeuroMorpho, and provides the tools needed to approximate missing information such as the soma's morphology. This method takes as its only input the available compact, yet incomplete, morphological tracings of the cells as acquired by neuroscientists. It uses a multiresolution approach that combines an initial, coarse mesh generation with subsequent on-the-fly adaptive mesh refinement stages using tessellation shaders. For the coarse mesh generation, a novel approach, based on the Finite Element Method, allows approximation of the 3D shape of the soma from its incomplete description. Subsequently, the adaptive refinement process performed in the graphic card generates meshes that provide good visual quality geometries at a reasonable computational cost, both in terms of memory and rendering time. All the described techniques have been integrated into NeuroTessMesh, available to the scientific community, to generate, visualize, and save the adaptive resolution meshes.

Development of an Antioxidant Phytoextract of Lantana grisebachii with Lymphoprotective Activity against In Vitro Arsenic Toxicity.

Phytochemicals have been presumed to possess prophylactic and curative properties in several pathologies, such as arsenic- (As-) induced immunosuppression. Our aim was to discover a lymphoprotective extract from Lantana grisebachii Stuck. (Verbenaceae) (LG). We assessed its bioactivity and chemical composition using cell-based assays. Fractions produced from a hexane extract acutely induced nitrite formation in T-activated cell cultures (P < 0.0001). Water extraction released a fraction lacking nitrite inducing activity in both lymphocyte types. Aqueous LG was found to be safe in proliferated and proliferating cells. The infusion-derived extract presented better antioxidant capacity in proportion to phenolic amount in lymphocytes (infusive LG-1i at 100 µ g/mL), which protected them against in vitro As-induced lymphotoxicity (P < 0.0001). This infusive LG phytoextract contained 10.23 ± 0.43 mg/g of phenolics, with 58.46% being flavonoids. Among the phenolics, the only predominant compound was 0.723 mg of chlorogenic acid per gram of dry plant, in addition to 10 unknown minor compounds. A fatty acid profile was assessed. It contained one-third of saturated fatty acids, one-third of ω 9, followed by ω 6 (~24%) and ω 3 (~4%), and scarce ω 7. Summing up, L. grisebachii was a source of bioactive and lymphoprotective compounds, which could counteract As-toxicity. This supports its phytomedical use and research in order to reduce As-related dysfunctions.

Distribution of (-)-hamanasic acid A in South American species of Flourensia and phytotoxic effects of leaf aqueous extracts.

The presence of the phytotoxic sesquiterpene (-)-hamanasic acid A {(-)HAA; 7-carboxy-8-hydroxy-1(2), 12(13)-dien-bisabolene} isolated from Flourensia campestris (FC), was investigated in the South American species of the genus, together with the evaluation of the phytotoxic activity of their leaf aqueous extracts. (-)HAA was identified and isolated from F. fiebrigii (FF) and F. oolepis (FO), being chemically (GC-MS, NMR, [a]) and biologically (bioassayed on lettuce) indistinguishable from that of FC, while no (-)HAA was found in F. hirta (FH), F. riparia (FR) and F. niederleinii (FN). Its leaf content in FF was similar to that found in FC (ca. 15 mg g-1 WT) and significantly higher than in FO (0.8 mg g-1 WT). The screening for the presence of (-)HAA in other species of Flourensia communities showed that its natural occurrence is restricted only to Flourensia species. No (-)HAA could be detected in any of the 37 -most representative- species of these communities (26 natives, 11 exotics), despite many of them belong to the same family and tribe as Flourensia spp. Leaf aqueous extracts of all Flourensia species exhibited strong inhibitory effects on lettuce germination and on root and shoot growth, regardless of the presence and content of (-)HAA. These results strongly suggest the existence of other powerful phytotoxic compounds in those Flourensia spp lacking (-)HAA. Our results clearly show that (-)HAA only pertains to some species of the genus Flourensia. Relative to previous exomorphologic groupings of the genus, our chemotaxonomic data would give support to the close link described between FC and FF, but not with FR. In addition, the fact that (-)HAA was also found in FO, which belongs to a second different line, also points out that species position in this lineage would deserve to be revisited. The restricted production of (-)HAA by Flourensia in their communities suggests its special link with the genus, and sustains its putative allelochemical role.

Multivariate optimization of a HS-SPME/GC-MS technique for the characterization of volatile compounds present in Hedeoma multiflorum Benth / Optimización Multivariada de una técnica HS-SPME/GC para la caracterización de los compuestos volátiles presentes en Hedeoma multiflorum Benth

The aim of the present work was to optimize the main experimental variables of a procedure using HS-SPME/GC-MS as the analytical methodology to establish the profile of the volatile compounds present in aerial parts of Hedeoma multiflorum Benth. The influence of the type of fiber, equilibrium time, extraction time and extraction temperature on the composition of the volatile compounds was determined using response surface methodology (RSM), and the parameters of the models were corroborated by multiple linear regressions. The results showed that the regression models generated adequately explained the data variation and represented the relationships between the parameters and their responses. The optimal analysis conditions from the contour plots were established (DVB/CAR/PDMS fiber, with a 10 min equilibrium time, 10 min extraction time, and 40°C). Under these conditions, 41 volatile components in the whole plant were determined, which represents more than those reported using hydrodistillation.

El objetivo del presente trabajo fue optimizar las principales variables experimentales de un procedimiento HS-SPME/GC para establecer el perfil de compuestos volátiles presentes en la parte aérea de Hedeoma multiflorum Benth. Se determinó la influencia de las variables tipo de fibra, tiempo de equilibrio, tiempo de extracción y temperatura de extracción sobre la composición de los volátiles, utilizando una met odología de superficie de respuesta (RSM) y los parámetros del modelo se corroboraron por regresión lineal múltiple. Los resultados demostraron que los modelos de regresión generados explican adecuadamente la variación de los datos y representaron significativamente las relaciones reales entre los parámetros y sus respuestas. Las condiciones óptimas de análisis fueron establecidas (DVB/CAR/PDMS, con un tiempo de equilibrio de 10 minutos, un tiempo de extracción de 10 minutos y trabajando a 40°C). Utilizando esta metodología, se determinaron 41 componentes volátiles en planta entera, más que los reportados mediante hidrodestilación.

Phenolic compound production in relation to differentiation in cell and tissue cultures of Larrea divaricata (Cav.).

The lignan nordihydroguaiaretic acid (NDGA) and its derivatives existing in Larrea divaricata species show a wide range of pharmacological activities which makes this genus an interesting target to consider the plant in vitro cultivation systems as a feasible alternative source for their production. These compounds are potentially useful in treating diseases related to heart condition, asthma, arteriosclerosis, viral and bacterial infections, inflammation and cancer. In the present study, calli, cell suspension cultures, and in vitro and wild plants of L. divaricata were investigated for their potential to synthesize phenolic compounds. Calli, both with and without organogenesis, produced NDGA and quercetin, as did plantlet and wild plants. NDGA was also produced by the cell suspension cultures, together with p-coumaric acid, ferulic acid and sinapyl alcohol. The capacity of undifferentiated tissues to form phenolic compounds is very limited, but when the calli underwent organogenesis, developing mainly adventitious shoots, the phenolic compound production increased significantly. Plantlets regenerated from adventitious shoots of L. divaricata calli did not show the same phenolic pattern as wild plants, with levels of NDGA and quercetin being 3.6- and 5.9-fold lower, respectively.

Phytotoxic activity in Flourensia campestris and isolation of (--)-hamanasic acid A as its active principle compound.

An aqueous extract from Flourensia campestris (Asteraceae) dry aerial parts showed strong inhibition on the germination and growth of Lactuca sativa. Based on bio-guided chromatographic fractionation of aq. extracts from dry and fresh leaves and spectroscopic means, (-)-hamanasic acid A (7-carboxy-8-hydroxy-1(2), 12(13)-dien-bisabolene (1)) was isolated as the most inhibitory active principle on germination (ECg(50)=2.9 mM) and on root (ECr(50)=1.5 mM)/shoot (ECs(50)=2.0 mM) growth. As measured by GC, and correlated with a simple designed 2D-TLC, compound 1 was distributed throughout the plant, with a remarkably high concentration (1.6%) in the leaves and the inflorescences. At least a quarter of the amount of 1 was found in aqueous extracts suggesting that leaching would be a key route for its release into the environment. By contrast, leaf essential oils (HD) between 0.5 and 1.5 µl ml(-1) did not show herbicidal effects and 1 was not found in them (TLC) nor among volatiles (HS-SPME). Volatile compositions were assessed by GC-FID and GC-MS and led to the identification of 23 compounds (4 monoterpenes and 19 sesquiterpenes) with a wide seasonal (spring-summer%) variation, represented principally by bicyclo-germacrene (37-6%), spathulenol (4-32%), globulol (20-0%), beta-caryophyllene (15-6%), caryophyllene oxide (1-13%) and bicycloelemene (10-1%), respectively. The high amount of 1 in F. campestris together with its feasibility of being extracted with water suggest that (-)-hamanasic acid A is an allelochemical in this species. Species-specific studies must be carried out to evaluate the potential of 1 as a natural herbicidal compound.

Identification of volatile compounds of Clinopodium odorum (Lamiaceae):A comparison between HS-SPME and classic hydrodistillation / Identificación de compuestos volátiles de Clinopodium odorum (Lamiaceae): Una comparación entre HS-SPME ehidrodestilación clásica

In the present work an analytical methodology to micro scale based on the use of the HS-SPME/GC-MS to determine volatile compounds present in Clinopodium odorum (Griseb.) Harley (Lamiaceae)was optimized and settled differences and similarities with itsessential oil. A systematic description of the volatile components of flowers, stems, leaves and combined aerial parts (whole plant) was constructed via GC-MS analyses of HS-SPME adsorbed compounds and of essential oils obtained through hydrodistillation of the same tissues. Pulegone was the main component of both the HS-SPME analysis and essential oil analysis. In addition, piperitenone oxide andpiperitone oxide were the other main components in the essential oil whereas in the HS-SPME analysis cis-isopulegone and menthone prevailed. The HS-SPME method can achieve comparable results to those obtained by essential oil analysis, by using very fewer samples, ashorter extraction time and a much simpler procedure.

En el presente trabajo se ha optimizado una metodología analítica a micro-escala basada en HS-SPME/GC-MS para determinar los compuestos volátiles presentes en Clinopodium odorum (Griseb.) Harley (Lamiaceae), y se establecieron diferencias y similitudes con su aceite esencial. Se realizó una descripción sistemática de los componentes volátiles de flores, tallos, hojas y partes aéreas combinadas(planta entera) a partir de los análisis por GC-MS a través del sistema HS-SPME y de los aceites esenciales. Pulegona fue el componenteprincipal tanto del análisis por HS-SPME, como del aceite esencial. Además, el óxido de piperitenona y el óxido de piperitona eran los otroscomponentes principales en el aceite esencial mientras que en el análisis por HS-SPME, prevalecieron cis-isopulegona y mentona. El método de HS-SPME puede lograr resultados comparables a los obtenidos por el análisis de aceite esencial, mediante el uso de muestras de menor tamaño, un tiempo de extracción más corto y un procedimiento más simple.

Determination of volatile organic compounds of Tagetes filifolia Lag. (Asteraceae) from Córdoba (Argentina) using HS-SPME analysis / Determinación de compuestos orgánicos volátiles de Tagetes filifolia Lag. (Asteraceae) proveniente de Córdoba (Argentina) utilizando análisis por HS-SPME

A headspace solid-phase microextraction (HS-SPME) method followed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC–FID) are described for the analysis of volatile compounds in Tagetes filifolia Lag. The composition of the total aerial parts of the plant (whole plant) and the inflorescences, leaves and stems were studied separately using HS-SPME. As a result, 54 compounds were determined, of which 47 were identified. The major components observed in this analysis were trans-anethole and estragole. The HS-SPME method used for the analysis of volatile compounds of T. filifolia is simple, fast, effective, free from the use of solvents, and permits by an analysis of small amounts of samples to achieve better results in terms of the determination of the composition than those reported in the literature for the analysis of essential oil.

Se realizó el análisis de los componentes volátiles de Tagetes filifolia Lag. utilizando el método de microextracción en fase sólida del espacio de cabeza con análisis posterior por cromatografía de gases acoplada a espectrometría de masas y por cromatografía de gases con detección por ionización de llama. Se estudio la composición de la planta entera así como también la de las inflorescencias, hojas y tallos por separado empleando el método de HS-SPME. Como resultado, se determinaron 54 compuestos de los cuales 47 fueron identificados. Los componentes mayoritarios observados en este análisis fueron: trans-anetol y estragol. El método de HS-SPME utilizado para el análisis de los compuestos volátiles de T. filifolia es simple, rápido, efectivo, libre de la utilización de solventes, y permitió mediante el análisis de pequeñas cantidades de muestra alcanzar mejores resultados en cuanto a la determinación de la composición, que los reportados en literatura para el análisis del aceite esencial.

Phytochemistry of Tagetes minuta L. (Asteraceae) from Córdoba, Argentina: comparative study between essential oil and HS-SPME analyses / Fitoquímica de Tagetes minuta L. (Asteraceae) originario de Córdoba, Argentina: estudio comparativo entre análisis del aceite esencial y análisis por HS-SPME

A headspace solid-phase microextraction (HS-SPME) method followed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC–FID) is described for the analysis of volatile compounds in Tagetes minuta L. Five types of SPME commercial fibers including PA, PDMS, CAR-PDMS, PDMS–DVB and DVB–CAR–PDMS were investigated and the best extraction was achieved with the mixed fiber DVB–CAR–PDMS. Parameters for HS-SPME in terms of equilibrium time of HS, fiber exposition time and extraction temperature were also investigated. Additionally, the composition of inflorescences, leaves and stems was also studied separately by HS-SPME. As a result, 68 compounds were determined and 53 were identified. A comparison was made between results obtained by HS-SPME–GC–MS and steam distillation of essential oil of the aerial parts of the plant. In both analyses, the major components were: cis-tagetenone and trans-tagetenone. Using much smaller samples, a shorter extraction time and a simpler procedure, the HS-SPME method can achieve similar results to those obtained by EO analysis. In conclusion, the HS-SPME method is simple, rapid, effective and free of solvent, and can be used for the analysis of volatile compounds in samples of different populations of T. minuta.

Se realizó el análisis de los componentes volátiles de T. minuta L. utilizando el método de micro-extracción en fase sólida del espacio de cabeza con análisis posterior por cromatografía de gases acoplada a espectrometría de masas y por cromatografía de gases con detección por ionización de llama. Se estudiaron cinco tipos de fibras comerciales que incluyeron a PA, PDMS, CAR-PDMS, PDMS–DVB y DVB–CAR–PDMS y se estableció que la fibra de DVB–CAR–PDMS es la que posee mejor comportamiento en el proceso de extracción. Se determinó el efecto del tiempo de equilibrio del espacio de cabeza, de la temperatura de extracción y del tiempo de exposición de la fibra sobre el proceso de HS-SPME. Adicionalmente, también se estudio por separado la composición de inflorescencias, hojas y tallos empleando el método de HS-SPME. Como resultado de este estudio se determinaron 68 componentes de los cuales 53 fueron identificados. Por otra parte se realizó una comparación de los resultados HS-SPME con el análisis del aceite esencial obtenido de las partes aéreas de la planta. En ambos casos, los componentes mayoritarios fueron: cis-tagetenona y trans-tagetenona. Utilizando una muy pequeña cantidad de muestra, un corto periodo de tiempo y un procedimiento más simple se lograron similares resultados a los obtenidos mediante el análisis del aceite esencial. En conclusión, el método de HS-SPME desarrollado es simple, rápido, efectivo y libre de la utilización de solventes, puede ser fácilmente implementado para el análisis de componentes volátiles provenientes de muestras de diferentes poblaciones de T. minuta.

Determination of volatile organic compounds of tagetes Argentina Cabrera (Asteraceae) using HS-SPME analysis / Determinación de compuestos orgánicos volátiles de tagetes Argentina Cabrera (Asteraceae) utilizando análisis por HS-SPME

A headspace solid-phase microextraction (HS-SPME) method followed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC-FID) is described for the analysis of volatile compounds in Tagetes argentina Cabrera. The composition of the totality of the aerial parts of the plant (whole plant) and the inflorescences, leaves and stems was studied separately using HS-SPME. As a result, 53 compounds were determined, of which 39 were identified. The major components were: cis-tagetenone, trans-tagetenone, trans-tagetone and cis-tagetone.Using a much smaller amount of samples, a shorter extraction time and a very simple procedure, the HS-SPME method can achieve similar or better results than those obtained by EO analysis. In conclusion, the HS-SPME method is simple, rapid, effective and free of solvent, and can be used for the analysis of volatile compounds in samples of different populations of T. Argentina.

Se realizó el análisis de los componentes volátiles de T. argentina Cabrera utilizando el método de micro-extracción en fase sólida del espacio de cabeza con análisis posterior por cromatografía de gases acoplada a espectrometría de masas y por cromatografía de gases con detección por ionización de llama. Se estudio la composición de la totalidad de las partes aéreas de la planta (planta entera) como así también de las inflorescencias, hojas y tallos por separado empleando el método de HS-SPME. Como resultado, se determinaron 53 compuestos de los cuales 39 fueron identificados. Los componentes mayoritarios fueron: cis-tagetenona, trans-tagetenona, trans-tagetona and cis-tagetona. Utilizando una muy pequeña cantidad de muestra, un corto periodo de tiempo y un procedimiento muy simple se lograron similares o mejores resultados a aquellos reportados mediante el análisis del aceite esencial. En conclusión, el método de HS-SPME es simple, rápido, efectivo, libre de la utilización de solventes y puede ser fácilmente implementado para el análisis de componentes volátiles provenientes de muestras de diferentes poblaciones de T. Argentina.