Influence of foliar nutrients on phenol levels in leaves of Eugenia uniflora
Carregando...
Data
2011-08
TĂtulo da Revista
ISSN da Revista
TĂtulo de Volume
Editor
Resumo
Eugenia unifl ora L., Myrtaceae, leaves contain high amounts of phenolic
compounds which are responsible for several pharmacological activities. In order to
evaluate the phenolics seasonal variation leaves were analysed on a monthly basis
during the period of two years for the contents of hydrolysable tannins, total phenols,
fl avonoids, and nutrients (N, P, K, S, Ca, Mg, Mn, Zn, Cu, and Fe). Results were
correlated with climate conditions (rainfall, humidity, and mean temperature) by
Principal Component and Cluster Analysis which allowed four groups to be distinguished
with respect to the age of the leaves and the content of some metals. Young leaves were
characterised by high levels of Zn and nitrogen whereas old leaves contained high
levels of Fe and calcium, and both groups had moderate amounts of phenolics. Adult
leaves were divided in two groups and results revealed that while one group had the
highest levels of all phenols and lowest amounts of Mn and Cu, the other showed
opposite quantities. The Canonical Correlation Analysis confi rmed a highly signifi cant
negative correlation between phenol contents and Mn and Cu. These facts suggested
that fl avonoids and tannins production depends of the amounts of foliar nutrients, Cu
and Mn in particular, which are cofactors of enzymes involved in phenol degradation
and lignin biosynthesis. This knowledge can improve this specie cultivation in order to
enhance the phenolic compounds concentration.
Descrição
Palavras-chave
Ellagitannins, Eugenia uniflora, Flavonoids, Foliar mineral nutrientes, Pitangueira
Citação
SANTOS, Rosa M. et al. Influence of foliar nutrients on phenol levels in leaves of Eugenia uniflora. Revista Brasileira de Farmacognosia, Curitiba, v. 21, n. 4, p. 581-586, July/Aug. 2011.