Low molecular weight polyphenols in leaves of Eucalyptus camaldulensis, E. globulus and E. rudis

Abstract

Ether soluble polyphenols from leaves of Eucalyptus camaldulensis, E. globulus and E. rudis have been studied. The phenolic aldehyde vanillin, the phenolic acids gallic, protocatechuic and ellagic acids, some flavonol glycosides (rutin, quercetin-3-arabinoside, quercetin-3,7-dirhamnoside, quercitrin, kaempferol-3-arabinoside and their aglycones), one flavanone (naringenin) and two flavones (luteolin and apigenin) were identified and quantified. Some ellagitannins, flavonols and flavanones were recognized according to their ultra-violet spectra. E. camaldulensis and E. rudis showed the highest concentrations and varieties of flavonol glycosides, whilst E. globulus was characterized by high concentrations of ellagitannins.

Flavonoid Composition of Citrus Juices

“…This approach has been successfully applied to problems involving trace analysis of Citrus flavanones, and can be expected to significantly improve the future development of LC-MS applications. Figure 10 provides an example of the HPLC-DAD-ESI-MS-MS analysis of a lemon juice, focusing on the peak corresponding to diosmin (43). Other interesting coupled methods are those based on HPLC separation coupled with electrochemical detection, being it either coulometric or amperometric [53m, 57a, 67].…”

“…Extraction with solvents of graded polarity [42] leads to the separation of flavonoids from the other components. Methanol [43], ethanol [44], acetone [45], water, ethyl acetate [46] and, to a lesser extent, propanol, dimethylformamide and combinations of these are frequently used for their extraction [47].…”

Identification of hydrolysable tannins in the reaction zone of Eucalyptus nitens wood by high performance liquid chromatography–electrospray ionisation mass spectrometry

“…Seikel and Hillis, 1970;Hillis and Yazaki, 1973;Hart and Hillis, 1974;Yazaki et al, 1993). Other studies have noted the presence of numerous ellagitannins in eucalypt branch wood but have not identified individual compounds (Conde et al, 1995;Cadahia et al, 1997). Some heartwood ellagitannins show anti-fungal activities in bioassays, including ellagitannin D-6 and D-13 from Eucalyptus species (Hart and Hillis, 1974).…”

Effect of exotic tree plantations on plant diversity and biological soil fertility in the Congo savanna: with special reference to eucalypts

“…Therefore the recovery of the initial population density could be easily achieved within one rainy season (8-9 months). The decrease in density could be better explained by a change in the microbial status of soil resulting from the disappearance of root exudates from grasses and the input of eucalypt litter essential oils (Li and Madden 1995) or polyphenols (Conde et al 1997) which have antibiotic activity. A decrease in microbial biomass could result in a shortage of food for free-living nematodes, since most of them are microbivorous.…”