title: Urinary metabolites from mango (Mangifera indica L. cv. Keitt) galloyl derivatives and in vitro hydrolysis of gallotannins in physiological conditions.
abstract: METHODS
  The absorption, metabolism, and excretion of mango galloyl derivatives (GD) has not yet been investigated in humans, and studies investigating repeated dosages of polyphenols are limited.
  
  
  RESULTS
  In this human pilot trial, healthy volunteers (age = 21-38 y, n = 11) consumed 400 g/day of mango-pulp (cv. Keitt) for 10 days, and seven metabolites of gallic acid (GA) were characterized and quantified in urine excreted over a 12 h period. Pyrogallol-O-sulfate and deoxypyrogallol-O-sulfate were found to be significantly more excreted between days 1 and 10 (p < 0.05) from 28.5 to 55.4 mg and 23.6 to 47.7 mg, respectively. Additionally, the in vitro hydrolysis of gallotannins (GTs) was monitored at physiological pH and temperature conditions, and after 4 h a significant (p < 0.05) shift in composition from relativity high to low molecular weight GTs was observed.
  
  
  CONCLUSIONS
  Seven metabolites of GA were identified in the urine of healthy volunteers, and two microbial metabolites were found to be significantly more excreted following 10 days of mango consumption. Mango GTs were also found to release free GA in conditions similar to the intestines. GTs may serve as a pool of pro-GA compounds that can be absorbed or undergo microbial metabolism.
authors.affiliation: Department of Nutrition and Food Science, Texas A&M University, College Station, TX, USA.
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Barnes
authors.affiliation: Department of Nutrition and Food Science, Texas A&M University, College Station, TX, USA.
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Krenek
authors.affiliation: College of Pharmacy, University of Tennessee, Memphis, TN, USA.
authors.forename: Bernd
authors.initials: B
authors.lastname: Meibohm
authors.affiliation: Department of Nutrition and Food Science, Texas A&M University, College Station, TX, USA.
authors.forename: Susanne U
authors.initials: SU
authors.lastname: Mertens-Talcott
authors.affiliation: Department of Nutrition and Food Science, Texas A&M University, College Station, TX, USA.
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Talcott
mesh_terms: D000328:Adult; D005260:Female; D005707:Gallic Acid / Q000378:metabolism* / Q000652:urine; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D047348:Hydrolyzable Tannins / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics* / Q000652:urine*; D007408:Intestinal Absorption; D008297:Male; D031022:Mangifera / Q000737:chemistry; D008970:Molecular Weight; D010865:Pilot Projects; D059808:Polyphenols / Q000032:analysis
chemical_list: D047348:Hydrolyzable Tannins; D059808:Polyphenols; D005707:Gallic Acid
keywords: Gallic acid; Gallotannins; Mango; Metabolomics