Análise dos compostos fenólicos da madeira do E. Grandis e do E. Urophilla do Triângulo Mineiro

Abstract

Phenolic compounds have been studied for a long time. The discovery of the biological activity of various plant-isolated phenolic compounds and the advent of new analytical and spectroscopic techniques such as mass spectrometry-coupled gas chromatography (GC / MS), high performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR) have contributed to a more efficient study of the higher polarity compounds, both quantitatively and qualitatively. Lately the phenolic compounds of eucalyptus wood have been object of study for the great adaptation of this tree to the Brazilian climatic conditions and its good yield in the pulp industry. Eucalyptus wood is also used for firewood, charcoal making, furniture making and civil construction. The primary objective of this work was to characterize the phenolic compounds and other extractives existing in the wood of Eucalyptus grandis and Eucalyptus urophilla species, cultivated in the Cerrado of Triângulo Mineiro. Hydrolysed tannins (galotanines and elagitanines), condensed tannins and flavonoids were the main components, although alcohols, carboxylic acids, fatty acids, esters and sugars were also identified. Several sugars, flavonoids and other compounds could not be identified. Catechin and hydroquinone were the most abundant phenolic compounds found by GC / MS and procyanidin was the main proanthocyanidin present in the extracts studied. Quantification of total phenols and proanthocyanidins was obtained by ultraviolet spectroscopy. The results were in agreement with those reported by other researchers, that is, the results showed similarities with other species studied, regardless of their geographical location. Infrared spectroscopy and especially nuclear magnetic resonance confirmed and complemented the results obtained by GC / MS and HPLC for the various extracts.