[Use of 2H-labeled compound and GC-MS in the isolation and identification of a metabolite of biphenyldimethyl-dicarboxylate in rat urine].

Abstract

Dimethyl-4, 4'-dimethoxy-5, 6, 5', 6'-dimethylenedioxy-biphenyl-2, 2'-dicarboxylate (biphenyldimethyldicarboxylate; BDD), a synthetic compound, has been used in the treatment of chronic hepatitis with good results in reducing s-GPT. Previous work in our laboratory studied its metabolites using 3H-labeled compound in combination with TLC and found that its main metabolic pathway is demethylation followed by conjugation with glucuronic acid. This paper reports the isolation and identification of a metabolite of BDD from rat urine using 2H-labeled compound and GC-MS. Rats fasted for 12 h were intragastrically given a mixture of 2H-labeled (consisting of monodeutero- and dideutero-BDD in the ratio about 1:1.3) and non-labeled BDD 150 mg/kg and placed in metabolism cages for urine collection. The 24 h urine was filtered and extracted three times each with 5 ml of methylenedichloride. The extracts were pooled and evaporated to dryness under reduced pressure at 35 degrees C. The residue was redissolved in chloroform and subjected to GC-MS analysis. The mass spectrum (m/z: 404, 405, 406; 373, 374, 375; 345, 346, 347; 330, 331, 332; etc) indicates that the molecular ionic and fragment peaks of the metabolite all have 14 amu less than those of BDD. This means that the metabolite isolated is mono-O-demethylated BDD. The result confirmed our findings reported previously.

• Authors: R M Xu, C Han, J X Xie, Z Y Song
• Journal: Yao xue xue bao = Acta pharmaceutica Sinica (Yao Xue Xue Bao) Vol. 25 Issue 10 Pg. 777-9 ( 1990) ISSN: 0513-4870 [Print] China
• PMID: 2099593 (Publication Type: English Abstract, Journal Article)

Chemical References

• Biphenyl Compounds
• Dioxoles
• Drugs, Chinese Herbal
• 7,7'-dimethoxy-(4,4'-bi-1,3-benzodioxole)-5,5'-dicarboxylic acid dimethyl ester
• 7-hydroxy-7'-methoxy-4,4'-bis(1,3-benzodioxole)-5,5'-dicarboxylic acid dimethyl ester

Topics

• Animals
• Biphenyl Compounds
• Dioxoles (metabolism, urine)
• Drugs, Chinese Herbal (metabolism)
• Gas Chromatography-Mass Spectrometry
• Male
• Rats
• Rats, Inbred Strains