RESUMO
The contents of tannins in the barks of barbatimão species, Stryphnodendron adstringens (Mart.) Cov. and S. polyphyllum (Mart.), were analysed monthly during one year. Results were correlated with climate conditions (rainfall, humidity and mean temperature) by chemometric methods. Principal component analysis of the data showed a tendency for higher production of tannins in the warm and wet season, suggesting that environmental factors can affect the levels of tannins in those plants.
A composição de taninos em cascas de espécies de barbatimão, Stryphnodendron adstringens (Mart.) Cov. and S. polyphyllum (Mart.), foi analisada mensalmente durante um ano. Os resultados foram correlacionados com as condições climáticas do período de coleta (precipitação, umidade e temperatura média) através de métodos quimiométricos. Análise de componentes principais dos dados mostrou uma tendência de maior produção de taninos na estação quente e chuvosa, sugerindo que os fatores ambientais podem afetar os teores de taninos nestas espécies.
RESUMO
Lychnophora ericoides is a Brazilian medicinal plant used in folk medicine as an anti-inflammatory and analgesic agent. The essential oils from leaves of two populations with and without scent, collected at 2-month intervals during an 1-year period, were analysed by GC-MS. The results were submitted to principal component and cluster analysis which allowed two groups of essential oils to be distinguished with respect to sampling site and scent: cluster I (Vianópolis site, with specimens exhibiting an aromatic scent) containing a high percentage of alpha-bisabolol (44.7-76.4%) and alpha-cadinol (10.9-23.5%), and cluster II (Cristalina site, with specimens without scent) characterised by a high content of (E)-nerolidol (31.3-47.1%) and ar-dihydro-turmerone (4.8-15.4%). The canonical discriminant analysis showed that using the data set of the seven sampling months and (E)-nerolidol and alpha-bisabolol as predictable variables, it was possible to distinguish between the samples harvested according to Cerrado seasons, dry winter (May-September) and humid summer (November-March). In addition, canonical correlation analysis between the soil sampling sites and the populations revealed a significant relationship between oil components and edaphic factors. Oxygenated sesquiterpenes and potential acidity, Al saturation, cationic exchange capacity, silt, and sand load as the first canonical variate were fairly strongly related to samples collected in Vianópolis site. On the other hand, monoterpenes and sesquiterpene hydrocarbons were strongly related to chemical balance in soils (organic matter, P and base saturation), which is related to samples at the Cristalina site. The chemovariation observed appears to be environmentally determined.
Assuntos
Asteraceae/química , Ecossistema , Óleos Voláteis/química , Óleos de Plantas/química , Óleos Voláteis/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , Óleos de Plantas/metabolismoRESUMO
A comparative study of tannin composition of three species known as barbatimão (Stryphnodendron adstringens, Stryphnodendron polyphyllum and Dimorphandra mollis) was developed by TLC, hydrolysis followed by PC, and colorimetry. Principal component analysis of the data obtained showed strong differentiation between the genus Dimorphandra and Stryphnodendron. Additionally, barks from the two Stryphnodendron sp. also presented considerable differences in the tannin structure.