Endocrine disrupting nonyl- and octylphenol in infant food in Germany: considerable daily intake of nonylphenol for babies.

Nonylphenol and octylphenol are persistent endocrine disrupters that are priority substances of the European Union Water Framework Directive. Their presence in the environment has caused increasing concern about their impact to human health. Infants are more sensitive to hormonal impacts of environmental chemicals than adults. The results of the present study indicate that nonylphenol is ubiquitous in foodstuffs for babies and toddlers commercially available in Germany, while octylphenol could only be determined in 80% of all food samples. The daily intakes based on consumption studies in µg nonylphenol kg⁻¹ body weight per day for high consumers in the baby category (0.23-0.65 µg kg⁻¹ bw d⁻¹) were relatively high. This could lead to a higher risk especially for babies.

Synthesis of defined endocrine-disrupting nonylphenol isomers for biological and environmental studies.

Nonylphenols are very important environmentally relevant substances in the focus of the world-wide endocrine disrupter research for over 25 years. Thus, they are among the 10 priority hazardous substances of the new European Union Water Framework Directive. They consist of a very complex mixture of isomers representing therefore a multi-component problem like dioxins or PCBs. As estrogenic effect and degradation behavior in the environment of individual 4-nonylphenols are heavily dependent on the structure and bulkiness of the side chain, it is absolutely necessary to consider the nonylphenol problem from an isomer-specific viewpoint. Therefore a range of 28 differently branched nonylphenol isomers were synthesized for biological and environmental studies. Nonylphenols with a quaternary alpha-carbon, like 4-(1,1,3,4-tetramethylpentyl)phenol (4-NP(95)) and 4-(1-ethyl-1,3,3-trimethylbutyl)phenol (4-NP(170)), were obtained by Friedel-Crafts alkylation of anisole with tertiary nonyl bromides and demethylation with BI(3). Nonylphenols with a tertiary alpha-carbon, such as 4-(1,2-dimethylheptyl)phenol (4-NP(10)) and 4-(1,2,4-trimethylhexyl)phenol (4-NP(41)), were accessible via coupling of p-methoxyphenylmagnesium bromide with ketones. Nonylphenols bearing a quaternary beta-carbon, like 4-(2,2-dimethylheptyl)phenol (4-NP(15)) and 4-(1,2,2-trimethylhexyl)phenol (4-NP(39)), were synthesized starting from 4'-methoxyisobutyrophenone. The compounds were characterized by GC-MS and NMR-spectroscopy. The individual isomers were designated according to the Juelich Nomenclature.