Influence of foliar nutrients on phenol levels in leaves of Eugenia uniflora

Abstract

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.

Identification and Antioxidant Activity of the Extracts of Eugenia uniflora Leaves. Characterization of the Anti-Inflammatory Properties of Aqueous Extract on Diabetes Expression in an Experimental Model of Spontaneous Type 1 Diabetes (NOD Mice)

“…Santos et al (2011) [ 39 ] studied phenolic compounds from E. uniflora leaves at different times of the year; the leaves were dried, ground and, after using acetone as the solvent extractor, the material was lyophilized. Our results, regarding total phenolic content and hydrolysable tannins, were similar for the leaves collected in September, i.e ., 82.61 mg/g and 112.21 mg/g samples, respectively.…”

Secondary Metabolites as Indicators of Copper Mine Tailing Stress in Sonneratia Alba J. Smith in Marinduque Island, Philippines

“…The production of secondary metabolites are affected by climate [17]. Seasonal production of flavonoids and hydrolysable tannins in some mangrove leaves depends on various biotic and abiotic factors, such as temperature, rainfall and humidity [7].…”

“…It appeared that the balance among micronutrients, such as Zn, Cu, and Mn, may influence a competition between the different classes of phenolic compounds [7]. It further suggested that flavonoids 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 [7].…”

<b>Allelopathic bioactivity of fresh and infused aqueous extracts of Brazilian cherry (<i>Eugenia uniflora</i> L.) on lettuce and maize

“…Infusions containing Brazilian cherry leaves are commonly used in popular medicine (Santos, Fortes, Ferri, & Santos, 2011), due to its wide variety of chemicals, produced in the leaves and fruit, particularly phenolic compounds (Bagetti, Facco, Rodrigues, Bizzotto, & Emanuelli, 2009), terpenes, alkaloids and flavonoids (Bakr, Mohamed, & Waly, 2017). These substances are produced by secondary metabolism and contribute to a diverse number of functions in plant, such as defense, seed dormancy, and reproduction (Moore, Andrew, Kulheim, & Foley, 2014).…”