Artemisia magellanica. Chemical Composition of the Essential Oil from an Unexplored Endemic Species of Patagonia.

The essential oil composition of the aerial parts of Artemisia magellanica Sch. Bip. (Asteraceae), native to Patagonia, was analyzed by GC-FID-MS. This is the first report on the essential oil composition of A. magellanica. A total of 113 components were identified accounting for 95.6-95.7 % of the oil. The essential oil was characterized by a high percentage of γ-costol (21.0-43.5 %), selina-4,11-diene, (Z)-ß-ocimene, (E)-ß-farnesene, (Z)-en-yn-dicycloether and 23 different esters (28.7 %). In turn, Artemisia biennis, a species native to North America, which is considered by some authors to be conspecific with A. magellanica, yielded an essential oil that was rich in (Z)-ß-ocimene (34.7 %), (E)-ß-farnesene (40.0 %) and the acetylenes (Z)- and (E)-en-yn-dicycloethers (11.0 %). Thus, as A. biennis lacks the three main components present in A. magellanica, namely γ-costol, 2-methylbutyl 2-methylbutyrate and selina-4,11-diene, these compounds could be considered as potential chemical markers for A. magellanica since they are absent or only found as minor constituents in other members of the genus. The data presented herein is also useful for genus taxonomy.

Acantholippia seriphioides: chemical biodiversity of wild populations from the Cuyo region in Argentina / Acantholippia seriphioides: biodiversidad química de poblaciones silvestres de la región de Cuyo de la Argentina

Nineteen samples from the aerial parts in bloom of Acantholippia seriphioides (Verbenaceae) were collected in three provinces belonging to the Cuyo region of Argentina. The essential oils were obtained by hydrodistillation, yielding between 0.57 and 2.46 percent (v/w). On the basis of the 13 main compounds determined by GC-FID-MS, representing the 87.2 and 95.3 percent of the total identified, four chemotypes were determined: carvacrol, thymol, cis and trans-dihydrocarvone and linalool-geraniol. The co-occurrence of different chemotypes in a same population indicates that the sample collection must be carefully done with the aid of an in situ olfactory testing of the plants, since no morphological differences at first sight were observed among them. The results showed in this study suggest that the pattern of variations for this species exists throughout its natural distribution area...

Se colectaron 19 muestras de partes aéreas en floración de Acantholippia seriphioides (Verbenaceae) de tres provincias de la región de Cuyo de la Argentina. Los aceites esenciales fueron obtenidos por hidrodestilación, arrojando rendimientos entre 0.57 y 2.46 por ciento (v/p). A partir de la determinación por GC-FID-MS de los 13 compuestos principales, que representaban entre el 87.2 y 95.3 por ciento del total de los identificados, fueron determinados cuatro quimiotipos: carvacrol, timol, cis y trans-dihidrocarvona, y linalol-geraniol. La co-ocurrencia de diferentes quimiotipos en una misma población indica que la colecta debe ser realizada con la ayuda de un examen olfatorio in situ de la planta, ya que, a primera vista no se observan diferencias morfológicas entre ellas. Los resultados sugieren que el patrón de variación para esta especie existe en toda su área de distribución natural...

Northwestern Argentina: a center of genetic diversity of lemon verbena (Aloysia citriodora PALÁU, Verbenaceae).

The aerial parts of lemon verbena (Aloysia citriodora PALÁU) are worldwide used due to their medicinal and aromatic properties. The essential-oil and acteoside contents have been proposed as the main quality markers for their pharmacological and organoleptic features. The northwestern region of Argentina has been repeatedly proposed as the place of origin for this species. For this reason, the essential-oil yields and chemical compositions of leaves of 25 populations of lemon verbena from both wild collections and experimental crops from this region were studied. Plants from six different collections were subsequently grown on the same experimental parcel located at Cerrillos, Salta province, during more than seven years. In addition, the acteoside contents determined in all the samples collected in 2010 showed significant variations (from 0.5 to 4.0%). Large differences were observed in the essential-oil composition and yields, which ranged from 0.4 to 2.1% (v/w). Nevertheless, most of the samples complied with the European Pharmacopoeia specifications. A remarkable chemical diversity with at least four clearly defined chemotypes was detected in this region. Therefore, it would be urgent to encourage actions to protect these genotypes of lemon verbena in the northwestern Argentina.

Identification of the genotype from the content and composition of the essential oil of lemon verbena (Aloysia citriodora Palau).

Aloysia citriodora accessions from cultivated material, botanical collections, and wild populations were studied by means of their biomass and essential oil production and composition to assist the selection of the most promising genotype. The study was carried out through both field experiments during two year's time and laboratory processes. Data were evaluated by means of univariate and multivariate techniques. Aloysia citriodora intraspecific variation was accounted for by differences in both yield and chemical profiles of the essential oils, but no differences were found in the biomass production. Three chemotypes were identified according to qualitative and quantitative differences of the essential oils. For the higher contents of neral and geranial, Mendoza accession was the most promising to be encouraged for future crops.

Volatile constituents of Aristolochia argentina.

The essential oils from leaves, aerial stems and underground organs of Aristolochia argentina Gris., a medicinal plant popularly known as "charrúa", were obtained by hydrodistillation and analyzed by GC and GC/MS. Forty-three components were identified in the oils. All parts of the plant afforded volatile oils characterized by high levels of argentilactone (57-89%) and the presence of undecatriene isomers (0.3-4.0%), these latter compounds providing the essential oils and extracts with an intense particular odor. Terpenes account for the remaining portion of the essential oils (5-29%). Bicyclogermacrene predominates in the aerial parts of the plant, whereas ishwarane is the main terpene of the subterranean organs. Argentilactone, a suspected carcinogenic compound, was also identified in a medicinal commercial tincture of A. argentina.