Phenolic acids gastrointestinal tract

Ferulic acid has often been reported as a model compound for the investigation of bioavailability of phenolic acids, as free or esterified forms (Table 2.3), since it is abundantly present in food. Absorption via the gastrointestinal tract has also been found for dimers of ferulic acid, or diferulic acids, released from cereal brans [Andreasen et al., 2001b]. 

Wu, X. Pittman, H.E. Hager, T. Hager, A. 2009. Phenolic acids in black raspberry and in the gastrointestinal tract of pigs fed black raspberry. Mol. Nutr. Food Res. 53 S76-S84. 

Disposition in the Body. Rapidly absorbed from the gastrointestinal tract and readily penetrates the skin. It is metabolised by conjugation to yield phenyl glucuronide and phenyl sulphate small amounts are oxidised to catechol and quinol which are also conjugated. Oxidation of these metabolites to quinones may tint the urine green. Acid-labile phenol conjugates are present endogenously in serum at concentrations of about 0.1 pg/ml. Phenol is a metabolite of benzene. 

Liothyronine sodium occurs in vivo together with levo-ihyroxinc sodium it has the same qualitative activities as thyroxine but is more active. It is absorbed readily from the gastrointestinal tract, is cleared rapidly from the bloodstream, and is hound more loosely to plasma proteins than is thyroxine, probably because of the less acidic phenolic hydroxyl group. 

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