Elucidating the structure of poly dopamine
Different expression of ERR-γ in different parts of the body may account for variations in bisphenol A effects.
For instance, ERR-γ has been found in high concentration in the placenta, explaining reports of high bisphenol accumulation in this tissue.
BPA seems to bind strongly to ERR-γ (dissociation constant = 5.5 n M), but only weakly to the ER.Despite these challenges, poly(dopamine) has found extraordinary utility in a range of applications including surface coatings, biotechnology and biomedicine, and water films that deposit onto a wide range of surfaces, as well as its inertness to harsh chemical environments.belonging to the group of diphenylmethane derivatives and bisphenols, with two hydroxyphenyl groups.Some, but not all, plastics that are marked with the Resin Identification Code 7 may be made with BPA." Type 7 is the catch-all "other" class, and some type 7 plastics, such as polycarbonate (sometimes identified with the letters "PC" near the recycling symbol) and epoxy resins, are made from bisphenol A monomer.Based on research by chemists at Bayer and General Electric, BPA has been used since the 1950s to harden polycarbonate plastics, and make epoxy resin, which is contained in the lining of food and beverage containers.At least 3.6 million tonnes (8 billion pounds) of BPA are used by manufacturers yearly.Polycarbonate plastic, which is clear and nearly shatterproof, is used to make a variety of common products including baby and water bottles, sports equipment, medical and dental devices, dental fillings sealants, CDs and DVDs, household electronics, eyeglass lenses, BPA is also used in the synthesis of polysulfones and polyether ketones, as an antioxidant in some plasticizers, and as a polymerization inhibitor in PVC.The European Food Safety Authority (EFSA) reviewed new scientific information on BPA in 2008, 2009, 2010, 20: EFSA's experts concluded on each occasion that they could not identify any new evidence which would lead them to revise their opinion that the known level of exposure to BPA is safe; however, the EFSA does recognize some uncertainties, and will continue to investigate them. The reaction is catalyzed by a strong acid, such as hydrochloric acid (HCl) or a sulfonated polystyrene resin.Industrially, a large excess of phenol is used to ensure full condensation; the product mixture of the cumene process (acetone and phenol) may also be used as starting material: A large number of ketones undergo analogous condensation reactions.As of 2014 there are no BPA labeling requirements for plastics in the US."In general, plastics that are marked with Resin Identification Codes 1, 2, 4, 5, and 6 are very unlikely to contain BPA.