Bisphenol A (BPA) is a chemical compound primarily used in the manufacturing of various plastics. It is a colourless solid which is soluble in most common organic solvents, but has very poor solubility in water. BPA is produced on an industrial scale by the condensation reaction of phenol and acetone. Global production in 2022 was estimated to be in the region of 10 million tonnes.
Nonylphenols are a family of closely related organic compounds composed of phenol bearing a 9 carbon-tail. Nonylphenols can come in numerous structures, all of which may be considered alkylphenols. They are used in manufacturing antioxidants, lubricating oil additives, laundry and dish detergents, emulsifiers, and solubilizers. They are used extensively in epoxy formulation in North America but its use has been phased out in Europe. These compounds are also precursors to the commercially important non-ionic surfactants alkylphenol ethoxylates and nonylphenol ethoxylates, which are used in detergents, paints, pesticides, personal care products, and plastics. Nonylphenol has attracted attention due to its prevalence in the environment and its potential role as an endocrine disruptor and xenoestrogen, due to its ability to act with estrogen-like activity. The estrogenicity and biodegradation heavily depends on the branching of the nonyl sidechain. Nonylphenol has been found to act as an agonist of the GPER (GPR30).
Estrogen receptors (ERs) are a group of proteins found inside cells. They are receptors that are activated by the hormone estrogen (17β-estradiol). Two classes of ER exist: nuclear estrogen receptors, which are members of the nuclear receptor family of intracellular receptors, and membrane estrogen receptors (mERs), which are mostly G protein-coupled receptors. This article refers to the former (ER).
Xenoestrogens are a type of xenohormone that imitates estrogen. They can be either synthetic or natural chemical compounds. Synthetic xenoestrogens include some widely used industrial compounds, such as PCBs, BPA, and phthalates, which have estrogenic effects on a living organism even though they differ chemically from the estrogenic substances produced internally by the endocrine system of any organism. Natural xenoestrogens include phytoestrogens which are plant-derived xenoestrogens. Because the primary route of exposure to these compounds is by consumption of phytoestrogenic plants, they are sometimes called "dietary estrogens". Mycoestrogens, estrogenic substances from fungi, are another type of xenoestrogen that are also considered mycotoxins.
Genistein (C15H10O5) is a naturally occurring compound that structurally belongs to a class of compounds known as isoflavones. It is described as an angiogenesis inhibitor and a phytoestrogen.
Homosalate is an organic compound used in some sunscreens. It is made by the Fischer–Speier esterification of salicylic acid and 3,3,5-trimethylcyclohexanol, the latter being a hydrogenated derivative of isophorone. Contained in 45% of U.S. sunscreens, it is used as a chemical UV filter. The salicylic acid portion of the molecule absorbs ultraviolet rays with a wavelength from 295 nm to 315 nm, protecting the skin from sun damage. The hydrophobic trimethyl cyclohexyl group provides greasiness that prevents it from dissolving in water.
HPTE, also known as hydroxychlor, p,p'-hydroxy-DDT, or 2,2-bis(4-hydroxyphenyl)-1,1,1-trichloroethane, is a metabolite of methoxychlor, a synthetic insecticide related to DDT. Like bisphenol A with similar chemical structure, HPTE is an endocrine disruptor which has estrogenic activity, and also inhibits Cholesterol side-chain cleavage enzyme and 3α-hydroxysteroid dehydrogenase (3α-HSD).
Polymeric immunoglobulin receptor (pIgR) is a transmembrane protein that in humans is encoded by the PIGR gene. It is an Fc receptor which facilitates the transcytosis of the soluble polymeric isoforms of immunoglobulin A and immunoglobulin M (pIg) and immune complexes. pIgRs are mainly located on the epithelial lining of mucosal surfaces of the gastrointestinal tract. The composition of the receptor is complex, including 6 immunoglobulin-like domains, a transmembrane region, and an intracellular domain. pIgR expression is under the strong regulation of cytokines, hormones, and pathogenic stimuli.
Estrogen-related receptor gamma (ERR-gamma), also known as NR3B3, is a nuclear receptor that in humans is encoded by the ESRRG gene. It behaves as a constitutive activator of transcription.
Coumestrol is a natural organic compound in the class of phytochemicals known as coumestans. Coumestrol was first identified as a compound with estrogenic properties by E. M. Bickoff in ladino clover and alfalfa in 1957. It has garnered research interest because of its estrogenic activity and prevalence in some foods, including soybeans, brussels sprouts, spinach and a variety of legumes. The highest concentrations of coumestrol are found in clover, Kala Chana, and Alfalfa sprouts.
Coumestan is a heterocyclic organic compound. Coumestan forms the central core of a variety of natural compounds known collectively as coumestans. Coumestans are oxidation products of pterocarpan that are similar to coumarin. Coumestans, including coumestrol, a phytoestrogen, are found in a variety of plants. Food sources high in coumestans include split peas, pinto beans, lima beans, and especially alfalfa and clover sprouts.
Bisphenol S (BPS) is an organic compound with the formula (HOC6H4)2SO2. It has two phenol functional groups on either side of a sulfonyl group. It is commonly used in curing fast-drying epoxy resin adhesives. It is classified as a bisphenol, and a close molecular analog of bisphenol A (BPA). BPS differentiates from BPA by possessing a sulfone group (SO2) as the central linker of the molecule instead of a dimethylmethylene group (C 2), which is the case of bisphenol A.
Bisphenol AF (BPAF) is a fluorinated organic compound that is an analogue of bisphenol A in which the two methyl groups are replaced with trifluoromethyl groups. It exists as a white to light-gray powder.
4-Methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene (MBP) is a metabolite of bisphenol A (BPA). MBP has potent estrogenic activity in vitro and in vivo, up to thousandfold stronger than BPA. It may also play a role in neuronal cell apoptosis and may increase risk for several forms of cancer.
Nitroapocynin is a mono-nitrated form of apocynin.
Bisphenol F is an organic compound with the chemical formula (HOC
6H
4)
2CH
2. It is structurally related to bisphenol A (BPA), a popular precursor for forming plastics, as both belong to the category of molecules known as bisphenols, which feature two phenol groups connected via a linking group. In BPF, the two aromatic rings are linked by a methylene connecting group. In response to concern about the health effects of BPA, BPF is increasingly used as a substitute for BPA.
Epiestriol, or epioestriol, also known as 16β-epiestriol or simply 16-epiestriol, as well as 16β-hydroxy-17β-estradiol, is a minor and weak endogenous estrogen, and the 16β-epimer of estriol. Epiestriol is used clinically in the treatment of acne. In addition to its estrogenic actions, epiestriol has been found to possess significant anti-inflammatory properties without glycogenic activity or immunosuppressive effects, an interesting finding that is in contrast to conventional anti-inflammatory steroids such as hydrocortisone.
The hydroxylation of estradiol is one of the major routes of metabolism of the estrogen steroid hormone estradiol. It is hydroxylated into the catechol estrogens 2-hydroxyestradiol and 4-hydroxyestradiol and into estriol (16α-hydroxyestradiol), reactions which are catalyzed by cytochrome P450 enzymes predominantly in the liver, but also in various other tissues.
Bisphenol A controversy centers on concerns and debates about the biomedical significance of bisphenol A (BPA), which is a precursor to polymers that are used in some consumer products, including some food containers. The concerns began with the hypothesis that BPA is an endocrine disruptor, i.e. it mimics endocrine hormones and thus has the unintended and possibly far-reaching effects on people in physical contact with the chemical.
11β-Chloromethylestradiol is a synthetic steroidal estrogen which was never marketed. It has very high affinity for the estrogen receptor and dissociates from it relatively slowly. It was originally thought that 11β-CME2 might be a covalent ligand of the estrogen receptors, but its binding was subsequently shown to be fully reversible. The relative binding affinity of 11β-CME2 for the estrogen receptors ranges from 230 to 3,320% of that of estradiol depending on the study. 11β-CME2 also has about 14% of the relative binding affinity of estradiol for sex hormone-binding globulin (SHBG). The compound has been developed as a radiolabel for the ERs.
