title: NMR use to quantify phlorotannins: the case of Cystoseira tamariscifolia, a phloroglucinol-producing brown macroalga in Brittany (France).
abstract: Among the most renowned natural products from brown algae, phlorotannins are phloroglucinol polymers that have been extensively studied, both for their biotechnological potential and their interest in chemical ecology. The accurate quantification of these compounds is a key point to understand their role as mediators of chemical defense. In recent years, the Folin-Ciocalteu assay has remained a classic protocol for phlorotannin quantification, even though it frequently leads to over-estimations. Furthermore, the quantification of the whole pool of phlorotannins may not be relevant in ecological surveys. In this study, we propose a rapid (1)H qNMR method for the quantification of phlorotannins. We identified phloroglucinol as the main phenolic compound produced by the brown macroalga Cystoseira tamariscifolia. This monomer was detected in vivo using (1)H HR-MAS spectroscopy. We quantified this molecule through (1)H qNMR experiments using TSP as internal standard. The results are discussed by comparison with a standard Folin-Ciocalteu assay performed on purified extracts. The accuracy and simplicity of qNMR makes this method a good candidate as a standard phlorotannin assay.
authors: Laboratoire Universitaire de Biodiversité et d׳Écologie Microbienne (EA 3882), IUT de Quimper, Université de Bretagne Occidentale, 6 rue de l׳Université, 29000 Quimper, France.
authors: Camille
authors: C
authors: Jégou
authors: Service commun de Résonance Magnétique Nucléaire, UFR Sciences, Université de Bretagne Occidentale, 6 avenue Victor Le Gorgeu-CS93837, 29238 Brest Cedex 3, France.
authors: Nelly
authors: N
authors: Kervarec
authors: Service commun de Résonance Magnétique Nucléaire, UFR Sciences, Université de Bretagne Occidentale, 6 avenue Victor Le Gorgeu-CS93837, 29238 Brest Cedex 3, France.
authors: Stéphane
authors: S
authors: Cérantola
authors: Laboratoire des Sciences de l׳Environnement Marin (UMR 6539), Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, rue Dumont d׳Urville, 29280 Plouzané, France.
authors: Isabelle
authors: I
authors: Bihannic
authors: Laboratoire des Sciences de l׳Environnement Marin (UMR 6539), Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, rue Dumont d׳Urville, 29280 Plouzané, France. Electronic address: valerie.stiger@univ-brest.fr.
authors: Valérie
authors: V
authors: Stiger-Pouvreau
mesh_terms: D005602:France; D009682:Magnetic Resonance Spectroscopy; D000459:Phaeophyceae / Q000378:metabolism; D010696:Phloroglucinol / Q000032:analysis* / Q000378:metabolism; D013634:Tannins / Q000032:analysis
chemical_list: D013634:Tannins; D010696:Phloroglucinol
keywords: Cystoseira tamariscifolia; Folin–Ciocalteu; HR-MAS; Phloroglucinol; Phlorotannin; qNMR