RESUMEN
The aerial parts of Lippia integrifolia (incayuyo) are widely used in northwestern and central Argentina for their medicinal and aromatic properties. The essential oil composition of thirty-one wild populations of L. integrifolia covering most of its natural range was analyzed by GC and GC-MS. A total of one hundred and fifty two terpenoids were identified in the essential oils. Sesquiterpenoids were the dominant components in all but one of the collections analyzed, the only exception being a sample collected in San Juan province where monoterpenoids amounted to 51%. Five clearly defined chemotypes were observed. One possessed an exquisite and delicate sweet aroma with trans-davanone as dominant component (usually above 80%). Another with an exotic floral odour was rich in oxygenated sesquiterpenoids based on the rare lippifoliane and africanane skeletons. The trans-davanone chemotype is the first report of an essential oil containing that sesquiterpene ketone as the main constituent. The absolute configuration of trans-davanone from L. integrifolia was established as 6S, 7S, 10S, the enantiomer of trans-davanone from 'davana oil' (Artemisia pallens). Wild plants belonging to trans-davanone and lippifolienone chemotypes were propagated and cultivated in the same parcel of land in Santa Maria, Catamarca. The essential oil compositions of the cultivated plants were essentially identical to the original plants in the wild, indicating that the essential oil composition is largely under genetic control. Specimens collected near the Bolivian border that initially were identified as L. boliviana Rusby yielded an essential oil practically identical to the trans-davanone chemotype of L. integrifolia supporting the recent view that L. integrifolia (Gris.) Hieron. and L. boliviana Rusby are synonymous.
Asunto(s)
Lippia/química , Lippia/genética , Aceites Volátiles/química , Aceites de Plantas/química , Plantas Medicinales/química , Plantas Medicinales/genética , Terpenos/aislamiento & purificación , Argentina , Cromatografía de Gases y Espectrometría de Masas , Estructura Molecular , Monoterpenos/química , Resonancia Magnética Nuclear Biomolecular , Componentes Aéreos de las Plantas/química , Reacción en Cadena de la Polimerasa , Sesquiterpenos/química , Estereoisomerismo , Terpenos/químicaRESUMEN
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...