Abstract
The object of this study was to elucidate the relationship between the chemical structure of purified condensed tannin polymers from tree species and their radical scavenging characteristics. By means of 13C-NMR spectrometry and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), four kinds of proanthocyanidins were identified: prorobinetinidins, profisetinidins, procyanidins, and prodelphinidins. The tannins were submitted to radical scavenging assays with DPPH and galvinoxyl radicals and from the time-course of the reactions was concluded: 1) Tannins with pyrogallol type B-ring scavenge radicals in the beginning faster than those with catechol type B-ring. 2) Tannins with catechol type B-ring needs more time to scavenge the same amount of radicals as those with pyrogallol type B-ring. 3) The IC50 values of tannins with catechol type B-ring decrease after longer reaction times with the galvinoxyl radical. 4) Radical scavenging with DPPH radical proceeds faster than that for the galvinoxyl radical.
©2011 by Walter de Gruyter Berlin Boston
Articles in the same Issue
- Original Papers
- Lignocellulosic biorefinery: process integration of hydrolysis and fermentation (SSF process)
- Study of stilbene and resin acid content of Scots pine heartwood by electrical impedance spectroscopy (EIS)
- Radical scavenging characteristics of condensed tannins from barks of various tree species compared with quebracho wood tannin
- Two-step hydrolysis of nipa (Nypa fruticans) frond as treated by semi-flow hot-compressed water
- Effect of acetic acid addition on chemical conversion of woods as treated by semi-flow hot-compressed water
- Oxidative cleavage of non-phenolic β-O-4 lignin model dimers by an extracellular aromatic peroxygenase
- Surface chemistry of vessel elements by FE-SEM, μ-XPS and ToF-SIMS
- Application of FT-NIR-DR and FT-IR-ATR spectroscopy to estimate the chemical composition of bamboo (Neosinocalamus affinis Keng)
- Chemical modification of lignin assisted by microwave irradiation
- Acidic oxidation of kraft lignin into aromatic monomers catalyzed by transition metal salts
- Effect of Physisporinus vitreus on wood properties of Norway spruce. Part 1: Aspects of delignification and surface hardness
- Effect of Physisporinus vitreus on wood properties of Norway spruce. Part 2: Aspects of microtensile strength and chemical changes
- Mode I critical stress intensity factor of wood and medium-density fiberboard measured by compact tension test
- Effect of oxalic acid pretreatment of wood chips on manufacturing medium-density fiberboard
- Experimental investigation of stress wave propagation in standing trees
- Relationships between mechanical properties of oak timber (Quercus robur L.)
- Estimating mechanical properties and specific gravity for five-year-old Eucalyptus tereticornis having broad moisture content range by NIR spectroscopy
- Effect of morphological variability of incrusted pit membranes on efficiency of transverse compression to improve liquid uptake
- Short Notes
- Performance of biopolymer films with reinforcing cellulose-containing fillers from pine pulp and bark and birch sawdust
- Efficacy of two organic biocides with co-added antioxidants
Articles in the same Issue
- Original Papers
- Lignocellulosic biorefinery: process integration of hydrolysis and fermentation (SSF process)
- Study of stilbene and resin acid content of Scots pine heartwood by electrical impedance spectroscopy (EIS)
- Radical scavenging characteristics of condensed tannins from barks of various tree species compared with quebracho wood tannin
- Two-step hydrolysis of nipa (Nypa fruticans) frond as treated by semi-flow hot-compressed water
- Effect of acetic acid addition on chemical conversion of woods as treated by semi-flow hot-compressed water
- Oxidative cleavage of non-phenolic β-O-4 lignin model dimers by an extracellular aromatic peroxygenase
- Surface chemistry of vessel elements by FE-SEM, μ-XPS and ToF-SIMS
- Application of FT-NIR-DR and FT-IR-ATR spectroscopy to estimate the chemical composition of bamboo (Neosinocalamus affinis Keng)
- Chemical modification of lignin assisted by microwave irradiation
- Acidic oxidation of kraft lignin into aromatic monomers catalyzed by transition metal salts
- Effect of Physisporinus vitreus on wood properties of Norway spruce. Part 1: Aspects of delignification and surface hardness
- Effect of Physisporinus vitreus on wood properties of Norway spruce. Part 2: Aspects of microtensile strength and chemical changes
- Mode I critical stress intensity factor of wood and medium-density fiberboard measured by compact tension test
- Effect of oxalic acid pretreatment of wood chips on manufacturing medium-density fiberboard
- Experimental investigation of stress wave propagation in standing trees
- Relationships between mechanical properties of oak timber (Quercus robur L.)
- Estimating mechanical properties and specific gravity for five-year-old Eucalyptus tereticornis having broad moisture content range by NIR spectroscopy
- Effect of morphological variability of incrusted pit membranes on efficiency of transverse compression to improve liquid uptake
- Short Notes
- Performance of biopolymer films with reinforcing cellulose-containing fillers from pine pulp and bark and birch sawdust
- Efficacy of two organic biocides with co-added antioxidants