The antioxidative activity of a total of 92 phenolic extracts from edible and nonedible plant materials (berries, fruits, vegetables, herbs, cereals, tree materials, plant sprouts, and seeds) was examined by autoxidation of methyl linoleate. The content of total phenolics in the extracts was determined spectrometrically according to the Folin-Ciocalteu procedure and calculated as gallic acid equivalents (GAE). Among edible plant materials, remarkable high antioxidant activity and high total phenolic content (GAE > 20 mg/g) were found in berries, especially aronia and crowberry. Apple extracts (two varieties) showed also strong antioxidant activity even though the total phenolic contents were low (GAE < 12.1 mg/g). Among nonedible plant materials, high activities were found in tree materials, especially in willow bark, spruce needles, pine bark and cork, and birch phloem, and in some medicinal plants including heather, bog-rosemary, willow herb, and meadowsweet. In addition, potato peel and beetroot peel extracts showed strong antioxidant effects. To utilize these significant sources of natural antioxidants, further characterization of the phenolic composition is needed.

Antioxidant activity of plant extracts containing phenolic compounds

The impetus for developing analytical methods for phenolic compounds in natural products has proved to be multifaceted. Hundreds of publications on the analysis of this category of compounds have appeared over the past two decades. Traditional and more advanced techniques have come to prominence for sample preparation, separation, detection, and identification. This review provides an updated and extensive overview of methods and their applications in natural product matrices and samples of biological origin. In addition, it critically appraises recent developments and trends, and provides selected representative bibliographic examples.

Extraction, separation, and detection methods for phenolic acids and flavonoids

Analytical separation and detection methods for flavonoids.

Xanthohumol and related prenylflavonoids from hops and beer: to your good health!

Pharmacognostic and pharmacological profile of Humulus Lupulus L.

Prenylflavonoids from Humulus lupulus

Prenylflavonoid variation in Humulus lupulus: distribution and taxonomic significance of xanthogalenol and 4′-O-methylxanthohumol

Leaf surface flavonoids of Chrysothamnus

Structure of the Bacillus subtilis phage SPO1-encoded type II DNA-binding protein TF1 in solution.

A new flavonoid, 2,5-dihydroxy-6,7-dimethoxyflavanone (1), was isolated from the leaf and stem exudates of Collinsonia canadensis along with three known flavones, baicalein-6,7-dimethyl ether (2), norwogenin-7,8-dimethyl ether (3), and tectochrysin (5-hydroxy-7-methoxyflavone).

Monika Ivancic

Papers

Prenylflavonoids from Humulus lupulus

Prenylflavonoid variation in Humulus lupulus: distribution and taxonomic significance of xanthogalenol and 4′-O-methylxanthohumol

Leaf surface flavonoids of Chrysothamnus

Structure of the Bacillus subtilis phage SPO1-encoded type II DNA-binding protein TF1 in solution.

A novel 2-hydroxyflavanone from Collinsonia canadensis