Analytical approaches to the determination of simple biophenols in forest trees such as Acer(maple), Betula(birch), Coniferus, Eucalyptus, Juniperus(cedar), Picea(spruce) and Quercus(oak)

Abstract

Analytical methods are reviewed for the determination of simple biophenols in forest trees such as Acer (maple), Betula (birch), Coniferus, Eucalyptus, Juniperus (cedar), Picea (spruce) and Quercus (oak). Data are limited but nevertheless clearly establish the critical importance of sample preparation and pre-treatment in the analysis. For example, drying methods invariably reduce the recovery of biophenols and this is illustrated by data for birch leaves where flavonoid glycosides were determined as 12.3 +/- 0.44 mg g(-1) in fresh leaves but 9.7 +/- 0.35 mg g(-1) in air-dried samples (data expressed as dry weight). Diverse sample handling procedures have been employed for recovery of biophenols. The range of biophenols and diversity of sample types precludes general procedural recommendations. Caution is necessary in selecting appropriate procedures as the high reactivity of these compounds complicates their analysis. Moreover, our experience suggests that their reactivity is very dependent on the matrix. The actual measurement is less contentious and high performance separation methods particularly liquid chromatography dominate analyses whilst coupled techniques involving electrospray ionization are becoming routine particularly for qualitative applications. Quantitative data are still the exception and are summarized for representative species that dominate the forest canopy of various habitats. Reported concentrations for simple phenols range from trace level (<0.1 microg g(-1)) to in excess of 500 microg g(-1) depending on a range of factors. Plant tissue is one of these variables but various biotic and abiotic processes such as stress are also important considerations.

Phenols in Leaves and Bark of Fagus sylvatica as Determinants of Insect Occurrences

“…Methods for the extraction, quantification and chemical characterization of phenolics in beech primarily concern the coccid Cryptococcus fagisuga that attacks north-American and European populations of beech [2,6] and methods have been developed to deal with the phenolic content of beech wood [3] reviewed in Bedgood et al . [14]. Different delivery of phenolics and chemical analysis gives divergent results, for an already fluctuating profile of phenolics concentrations, it is essential that the analytical protocol be kept constant throughout the study in all beech forests.…”

“…In June, when the majority of the plant species were in full growth approximately 50 g of bark, both the inner and the outer layers from three sides of the trunk at breast height and 120° angular distance, was removed, brush cleaned, and put in dry-ice (CO 2 ). Following standard analytical procedures [2,14], we freeze dried, ground, and extracted the phenolic content of 40 g of bark (5 × 100 mL MeOH) for 24 h at room temperature (∼25 °C).…”

Modelling of the adsorption of phenolic acids onto α,γ–alumina particles

“…1. Indeed, they were evidenced in several humus of soils and in fruit peels [14][15][16][17][18][19][20] and these three acids differ only by adding an OH group on the aromatic ring. Adsorption of organic acids onto oxides is maximum for pH values around the pK a of acids [10,[21][22][23][24] and depends on several parameters such as pH, ionic strength, and number and position of ionizable polar functional groups [21,[24][25][26][27][28][29][30][31][32].…”

Exploration of natural enzyme inhibitors with hypoglycemic potentials amongst Eucalyptus Spp. by in vitro assays

“…After boiling the tube for 5 min, it was preincubated for 5 min at 37 ℃. Different concentrations (10,20,40,60,80 and 100 µg/mL) of the extracts of EC, EG and ECA were prepared by dissolving in 1 mL of 0.1% dimethyl sulfoxide. Then 0.2 mL of the extract of particular concentrations was put in the tube containing the substrate solution.…”

“…have been used in folk medicine for the treatment of ailments such as colds, fever, toothache, diarrhea and snake bites. Uses of Eucalyptus leaf hot decoctions as "herbal tea" have been recorded in Aboriginal, European and British Pharmacopeias for the traditional remedy of type DM [10][11][12][13][14][15][16][17][18][19][20][21] . A rich literature exists, reporting over 500 Eucalyptus species with different pharmacological actions [11][12][13][14][15][16][17][18][19][20][21][22] .…”