title: Relative oral bioavailability of glycidol from glycidyl fatty acid esters in rats.
abstract: In order to quantify the relative bioavailability of glycidol from glycidyl fatty acid esters in vivo, glycidyl palmitoyl ester and glycidol were orally applied to rats in equimolar doses. The time courses of the amounts of glycidol binding to hemoglobin as well as the excretion of 2,3-dihydroxypropyl mercapturic acids were determined. The results indicate that glycidol is released from the glycidyl ester by hydrolysis and rapidly distributed in the organism. In relation to glycidol, there was only a small timely delay in the binding to hemoglobin for the glycidol moiety released from the ester which may be certainly attributed to enzymatic hydrolysis. In both cases, however, an analogous plateau was observed representing similar amounts of hemoglobin binding. With regard to the urinary excretion of mercapturic acids, also similar amounts of dihydroxypropyl mercapturic acids could be detected. In an ADME test using a virtual double tag (³H, ¹⁴C) of glycidyl palmitoyl ester, a diverging isotope distribution was detected. The kinetics of the ¹⁴C-activity reflected the kinetics of free glycidol released after hydrolysis of the palmitoyl ester. In view of this experimental data obtained in rats, it is at present justified for the purpose of risk assessment to assume complete hydrolysis of the glycidyl ester in the gastrointestinal tract. Therefore, assessment of human exposure to glycidyl fatty acid ester should be regarded as an exposure to the same molar quantity of glycidol.
authors: Department of Food Safety, Federal Institute for Risk Assessment BfR, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany.
authors: Klaus E
authors: KE
authors: Appel
authors: Klaus
authors: K
authors: Abraham
authors: Edith
authors: E
authors: Berger-Preiss
authors: Tanja
authors: T
authors: Hansen
authors: Elisabeth
authors: E
authors: Apel
authors: Sven
authors: S
authors: Schuchardt
authors: Carla
authors: C
authors: Vogt
authors: Nadiya
authors: N
authors: Bakhiya
authors: Otto
authors: O
authors: Creutzenberg
authors: Alfonso
authors: A
authors: Lampen
mesh_terms: D000111:Acetylcysteine / Q000031:analogs & derivatives / Q000652:urine; D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D015415:Biomarkers / Q000097:blood / Q000378:metabolism / Q000652:urine; D001711:Biotransformation; D002250:Carbon Radioisotopes; D004852:Epoxy Compounds / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics*; D005506:Food Contamination; D006454:Hemoglobins / Q000378:metabolism; D006868:Hydrolysis; D008297:Male; D010168:Palmitates / Q000097:blood / Q000493:pharmacokinetics*; D010169:Palmitic Acids / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics*; D020005:Propanols / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution; D014316:Tritium; D014633:Valine / Q000031:analogs & derivatives / Q000097:blood
chemical_list: D015415:Biomarkers; D002250:Carbon Radioisotopes; D004852:Epoxy Compounds; D006454:Hemoglobins; C416044:N-(2,3-dihydroxypropyl)valine; D010168:Palmitates; D010169:Palmitic Acids; D020005:Propanols; D014316:Tritium; D014633:Valine; C004312:glycidol; D000111:Acetylcysteine