Limitations of Folin assays of foliar phenolics in ecological studies

Citation
Hm. Appel et al., Limitations of Folin assays of foliar phenolics in ecological studies, J CHEM ECOL, 27(4), 2001, pp. 761-778
Citations number
38
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Environment/Ecology
Journal title
JOURNAL OF CHEMICAL ECOLOGY
ISSN journal
0098-0331 → ACNP
Volume
27
Issue
4
Year of publication
2001
Pages
761 - 778
Database
ISI
SICI code
0098-0331(200104)27:4<761:LOFAOF>2.0.ZU;2-B
Abstract
We examined the response of the widely used Folin-Denis assay to purified t annins from IG woody plant species and to three commercial polyphenol prepa rations often used as standards, The reagent's response to these chemical m ixtures differed significantly among sources (tree species, commercial prep arations) and sampling dates, even though the mixtures contained the same t otal dry weight of tannins. . Response to commercial standards usually did not resemble response to actual plant tannin and produced estimates that di ffered from actual concentrations by as much as twofold. Species-based and seasonal differences in polyphenol composition are evidently responsible Fo r these variable results. Reagents that depend on redox reactions, such as the Folin-Denis, do not produce reliable absolute or relative quantificatio n of phenolics when different species or samples from different dates are c ompared, and use of commercial standards does not resolve this problem.