Additional oxidized and alkyl chain breakdown metabolites of the plasticizer DINCH in urine after oral dosage to human volunteers

详细信息    查看全文

• 作者：André Schütze ; Rainer Otter ; Hendrik Modick ; Angelika Langsch…
• 关键词：DINCH ; Phthalate substitute ; Human metabolism ; Urinary metabolites ; Excretion fractions ; Human biomonitoring
• 刊名：Archives of Toxicology
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：91
• 期：1
• 页码：179-188
• 全文大小：
• 刊物主题：Pharmacology/Toxicology; Occupational Medicine/Industrial Medicine; Environmental Health; Biomedicine, general;
• 出版者：Springer Berlin Heidelberg
• ISSN：1432-0738
• 卷排序：91

文摘

Hexamoll® DINCH® (diisononyl-cyclohexane-1,2-dicarboxylate) is a new high molecular weight plasticizer and a non-aromatic phthalate substitute. In this follow-up study, we further investigated the extensive oxidative metabolism of Hexamoll® DINCH® after oral dosage of 50 mg to three male volunteers (0.552–0.606 mg/kg body weight). Urine samples were consecutively collected over 48 h post-dose. Chemical analysis was carried out by HPLC–MS/MS with labeled internal standards. New metabolites were tentatively identified and quantified via fragmentation analogies and new standard substances. In addition to the five urinary DINCH metabolites previously reported by us, we identified two groups of extensively oxidized metabolites characterized (a) by multiple side chain oxidation and breakdown and (b) by hydroxylation at the cyclohexane ring. The five newly identified carboxylated breakdown metabolites represented in sum 5.12 ± 0.49 % of the applied dose. MCHxCH (cyclohexane-1,2-dicarboxylic acid mono carboxyhexyl ester) was identified as a major metabolite (2.71 ± 0.34 %) and thus represents the second most important specific metabolite of DINCH after OH-MINCH (10.7 ± 2.1 %). Less than 1 % was excreted as ring-hydroxylated metabolites (four metabolites identified). Based upon a new reference standard, we can also update oxo-MINCH to 2.6 % of the applied dose. This follow-up study increases the total amount of the recovered dose from 39.2 to 45.7 % and describes a new major metabolite (MCHxCH) of DINCH that can be used as an additional valuable and specific biomarker to assess DINCH® exposure in future human biomonitoring studies.