title: Catechin glucosides: occurrence, synthesis, and stability.
abstract: Catechins are flavonoids with suggested health benefits, but are unstable during storage, processing and, after ingestion, during gut transit. We hypothesized that catechin glucosides, which occur in various plants, could be more stable than unsubstituted catechin, and additionally be deglucosylated in the gut and so act to deliver catechin in a form able to be absorbed. (+)-Catechin O-glucosides from various sources have been used in the course of this investigation. (+)-Catechin 3'-O-beta-D-glucopyranoside (C3'G), (+)-catechin 5-O-beta-D-glucopyranoside (C5G), and (+)-catechin 3-O-beta-D-glucopyranoside (C3G) were chemically synthesized. (+)-Catechin 4'-O-beta-D-glucopyranoside (C4'G) and (+)-catechin 7-O-beta-D-glucopyranoside (C7G) were prepared enzymically using preparations from lentil and barley. In general, but with some exceptions, the (+)-catechin glucosides were more stable between pH 4 and 8 than (+)-catechin, with C3'G exhibiting greatest stability. The intestinal metabolism of (+)-catechin and all (+)-catechin glucosides in the gut was determined by perfusion of rat intestine in vivo. C3'G and C5G were extensively deglycosylated in the gut, and C3'G showed greatest apparent "absorption" as calculated by the difference between effluent and influent. The results show the potential of catechin glucosides, especially C3'G, as more stable prescursors of catechin.
authors.affiliation: Nestle Research Center, Vers chez les Blanc, 1000 Lausanne 26, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Raab
authors.forename: Denis
authors.initials: D
authors.lastname: Barron
authors.forename: Francia Arce
authors.initials: FA
authors.lastname: Vera
authors.forename: Vanessa
authors.initials: V
authors.lastname: Crespy
authors.forename: Manuel
authors.initials: M
authors.lastname: Oliveira
authors.forename: Gary
authors.initials: G
authors.lastname: Williamson
mesh_terms: D002392:Catechin / Q000032:analysis* / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004355:Drug Stability; D005772:Gastrointestinal Transit; D005960:Glucosides / Q000032:analysis* / Q000096:biosynthesis / Q000737:chemistry; D001467:Hordeum / Q000737:chemistry; D006801:Humans; D027806:Lens Plant / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods; D008958:Models, Molecular; D018515:Plant Leaves / Q000737:chemistry; D010944:Plants / Q000737:chemistry*; D027861:Prunus / Q000737:chemistry
chemical_list: D005960:Glucosides; D002392:Catechin