Xenobiotics in food. I. Metabolic phthalate degradation.

In conjunction with the programme of monitoring the food contamination by one of the most widely distributed contaminants--phthalic acid esters--the present investigation was focused on the elucidation of metabolic transformations of phthalates in the organism of the rat and humans and on assessment of the phthalate content of beef and pork liver. As a model substance di-(2-ethylhexyl)phthalate was selected. The paper contains new information on the mechanism of metabolic oxidative phthalate degradation in the rat, identifies the structure of intermediary products and suggests a reaction breakdown pattern.

Biotransformation of acrolein in rat: excretion of mercapturic acids after inhalation and intraperitoneal injection.

Biotransformation of acrolein (ACR) was studied in vivo in the rat following inhalation and ip administration. The major and minor urinary metabolites were 3-hydroxypropylmercapturic acid (HPMA) and 2-carboxyethylmercapturic acid (CEMA), respectively. Male Wistar rats were exposed to ACR, 23, 42, 77 and 126 mg/m3, for 1 hr.

Metabolic pathways of 1-butyl [3-13C]acrylate. Identification of urinary metabolites in rat using nuclear magnetic resonance and mass spectroscopy.

1-Butylacrylate, an industrial monomer, is rapidly metabolized by carboxylesterase-catalyzed hydrolysis to acrylic acid and 1-butanol. Acrylic acid enters the intermediary metabolism and is efficiently degraded to carbon dioxide as the metabolic end product. To obtain a virtually complete metabolic pattern, rats were dosed by a single intraperitoneal dose of 1 mmol/kg 1-butyl [3-13C]acrylate.

Biotransformation of diethenylbenzenes. IV. A simple high-performance liquid chromatographic method for separation of urinary metabolites of 1,3-diethenylbenzene on analytical and semi-preparative scales.

A simple ion-suppression separation on reversed-phase columns, which is applicable for both analytical and semi-preparative work, is described. Six urinary metabolites of 1,3-diethenylbenzene (I), namely 1-(3-ethenylphenyl)-1,2-dihydroxyethane beta-D-glucosiduronates (two isomers, II and III), N-acetyl-S-[1-(3-ethenylphenyl)-2-hydroxyethyl]cysteine (IV), N-acetyl-S-[2-(3-ethenylphenyl)-2-hydroxyethyl]cysteine (V), 3-ethenylphenylmandelic acid (VI) and 3-ethenylphenylglyoxylic acid (VII), were isolated (Fig. 1).

Biotransformation of diethenylbenzenes. III: Identification of metabolites of 1,3-diethenylbenzene in rat.

1. Biotransformation of 1,3-diethenylbenzene (1) in rat gave four major metabolites, namely, 3-ethenylphenylglyoxylic acid (2), 3-ethenylmandelic acid (3), N-acetyl-S-[2-(3-ethenylphenyl)-2-hydroxyethyl]-L-cysteine (4) and N-acetyl-S-[1-(3-ethenylphenyl)-2-hydroxyethyl]-L-cysteine (5) were isolated from urine and identified by n.m.