Use of fluorescein isothiocyanate isomer I to study the mechanism of intestinal absorption of fucoidan sulfate in vivo and in vitro

A new method to label fucoidan sulfate was established with tyramine and fluorescein isothiocyanate isomer I (FITC). Fluorescence spectrophotometry and high performance liquid chromatography verified the successful labelling of fucoidan by FITC. The results of the single‐pass intestinal perfusion indicated that the jejunum and ileum are the main absorption sites, and there was carrier saturation. In addition, fucoidan sulfate at 1 mg/ml had no...