Aerobic degradation of tetramethyl bisphenol F (TMBPF) with activated sludge: Kinetics and biotransformation products.

This study investigated the bio-degradation kinetics of tetramethyl bisphenol F (TMBPF), a non-estrogenic alternative to bisphenol A (BPA). Batch biotransformation experiments were performed whereby samples were inoculated with activated sludge and analysed using liquid chromatography-Orbitrap-tandem mass spectrometry (LC-Orbitrap-MS) utilising two non-targeted workflows (commercial and freely available online) for biotransformation products (BTP) identification. The degradation of TMBPF followed single first-order reaction kinetics and depended on the initial concentration (c) with faster degradation -k = 0.

Characterization of a new polymeric food contact coating with emphasis on the chemical analysis and safety assessment of non-intentionally added substances (NIAS).

Regulators have established safety requirements for food packaging raw materials and finished products, including by-products of polymer synthesis known as non-intentionally added substances (NIAS). However, there are no official guidance or regulations for best practices to evaluate the safety of NIAS. Here we described the process we followed to identify, characterize, and prioritize for safety assessment low molecular weight NIAS from an epoxy coating (V70) made with tetramethyl bisphenol F-based diglycidyl ether resin (TMBPF-DGE).

Evidence of Absence: Estrogenicity Assessment of a New Food-Contact Coating and the Bisphenol Used in Its Synthesis.

Consumer concerns about exposure to substances found in food contact materials with estrogenic activity (EA) have created substantial demand for alternatives. We assessed the potential EA of both a new bisphenol monomer used to synthesize polymeric coatings for metal food-contact applications and the nonintentionally added substances (NIAS) that may migrate into food. We evaluated tetramethyl bisphenol F (TMBPF) using in vitro and in vivo assays.

Setting occupational exposure limits for unstudied pharmaceutical intermediates using an in vitro parallelogram approach.

Occupational exposure limits for unstudied pharmaceutical synthetic intermediates are often established under the assumption that penultimate and near-ultimate intermediates have the same structure-activity and dose-response as the ultimate active pharmaceutical ingredient (API). This is seldom the case because moieties that render biological activity to the API are often protected or modified for synthetic purposes. Incorrectly assuming that intermediates have biological activity similar to the API may lead to excessive exposure controls that in turn impose unnecessary ergonomic hazards on workers and greatly reduces the scale and efficiency of production.

The aryl hydrocarbon receptor agonist 3,3',4,4',5-pentachlorobiphenyl induces distinct patterns of gene expression between hepatoma and glioma cells: chromatin remodeling as a mechanism for selective effects.

Genome-wide oligonucleotide DNA microarrays and real time RT-PCR were used to assess differential gene expression in rat glioma and hepatoma cell lines after exposure to the aryl hydrocarbon receptor (AhR) agonist 3,3',4,4',5-pentachlorobiphenyl (penta-CB). Under maximal inducing concentrations for cytochrome P450 1A1 (CYP1A1) in H4IIE rat hepatoma cells, both H4IIE and C6 rat glioma cells were exposed to sub-micromolar concentrations of penta-CB for 24h. Differential gene expression for approximately 28,000 gene probes were computationally analyzed and compared.