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4-Hydroxyestriol
4-Hydroxyestriol, also known as estra-1,3,5(10)-triene-3,4,16α,17β-tetrol, is an endogenous catechol estrogen and metabolite of estriol. It has been found in pregnancy urine. See also * 2-Hydroxyestriol 2-Hydroxyestriol, also known as estra-1,3,5(10)-triene-2,3,16α,17β-tetrol, is an endogenous catechol estrogen and metabolite of estriol. It is a suspected carcinogen A carcinogen is any substance, radionuclide, or radiation that promotes car ... References Cyclopentanols Sterols Phenols Estranes Estrogens Human metabolites {{steroid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catechol Estrogen
A catechol estrogen is a steroidal estrogen that contains catechol (1,2-dihydroxybenzene) within its structure. The catechol estrogens are endogenous metabolites of estradiol and estrone and include the following compounds: * 2-Hydroxylated: ** 2-Hydroxyestradiol ** 2-Hydroxyestrone ** 2-Hydroxyestriol * 4-Hydroxylated: ** 4-Hydroxyestradiol ** 4-Hydroxyestrone ** 4-Hydroxyestriol The most abundant catechol estrogen in serum and urine is 2-hydroxyestrone, with 2-hydroxyestradiol and 2-hydroxyestriol also being formed, while the principal 4-hydroxy catechol estrogen, 4-hydroxyestrone, is present in only small amounts in urine. 4-Hydroxyestriol has been detected in the urine of pregnant women. The catechol estrogens are formed from estradiol and estrone by cytochrome P450 enzymes predominantly in the liver but also in extrahepatic tissues, and are metabolized by catechol O-methyltransferase (COMT) into methoxylated estrogens such as 2-methoxyestradiol and 4-methoxyestrone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2-Hydroxyestriol
2-Hydroxyestriol, also known as estra-1,3,5(10)-triene-2,3,16α,17β-tetrol, is an endogenous catechol estrogen and metabolite of estriol. It is a suspected carcinogen A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive subst ... of carcinogenicity category 2. See also * 4-Hydroxyestriol * 2-Methoxyestriol References Phenols Cyclopentanols Sterols Carcinogens Estranes Human metabolites {{Steroid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endogenous
Endogenous substances and processes are those that originate from within a living system such as an organism, tissue, or cell. In contrast, exogenous substances and processes are those that originate from outside of an organism. For example, estradiol is an endogenous estrogen hormone produced within the body, whereas ethinylestradiol is an exogenous synthetic estrogen, commonly used in birth control pills Oral contraceptives, abbreviated OCPs, also known as birth control pills, are medications taken by mouth for the purpose of birth control. Female Two types of female oral contraceptive pill, taken once per day, are widely available: * The combin .... References External links *{{Wiktionary-inline, endogeny Biology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metabolite
In biochemistry, a metabolite is an intermediate or end product of metabolism. The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, catalytic activity of their own (usually as a cofactor to an enzyme), defense, and interactions with other organisms (e.g. pigments, odorants, and pheromones). A primary metabolite is directly involved in normal "growth", development, and reproduction. Ethylene exemplifies a primary metabolite produced large-scale by industrial microbiology. A secondary metabolite is not directly involved in those processes, but usually has an important ecological function. Examples include antibiotics and pigments such as resins and terpenes etc. Some antibiotics use primary metabolites as precursors, such as actinomycin, which is created from the primary metabolite tryptophan. Some sugars are metabolites, such as fructose or glucose, which ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estriol
Estriol (E3), also spelled oestriol, is a steroid, a weak estrogen, and a minor female sex hormone. It is one of three major endogenous estrogens, the others being estradiol and estrone. Levels of estriol in women who are not pregnant are almost undetectable. However, during pregnancy, estriol is synthesized in very high quantities by the placenta and is the most produced estrogen in the body by far, although circulating levels of estriol are similar to those of other estrogens due to a relatively high rate of metabolism and excretion. Relative to estradiol, both estriol and estrone have far weaker activity as estrogens. In addition to its role as a natural hormone, estriol is used as a medication, for instance in menopausal hormone therapy; for information on estriol as a medication, see the estriol (medication) article. Biological activity Estriol is an estrogen, specifically an agonist of the estrogen receptors ERα and ERβ. It is a far less potent estrogen than is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pregnancy
Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occurs by sexual intercourse, but can also occur through assisted reproductive technology procedures. A pregnancy may end in a live birth, a miscarriage, an induced abortion, or a stillbirth. Childbirth typically occurs around 40 weeks from the start of the last menstrual period (LMP), a span known as the gestational age. This is just over nine months. Counting by fertilization age, the length is about 38 weeks. Pregnancy is "the presence of an implanted human embryo or fetus in the uterus"; implantation occurs on average 8–9 days after fertilization. An ''embryo'' is the term for the developing offspring during the first seven weeks following implantation (i.e. ten weeks' gestational age), after which the term '' fetus'' is used until birth. Signs a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urine
Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra. Cellular metabolism generates many by-products that are rich in nitrogen and must be cleared from the bloodstream, such as urea, uric acid, and creatinine. These by-products are expelled from the body during urination, which is the primary method for excreting water-soluble chemicals from the body. A urinalysis can detect nitrogenous wastes of the mammalian body. Urine plays an important role in the earth's nitrogen cycle. In balanced ecosystems, urine fertilizes the soil and thus helps plants to grow. Therefore, urine can be used as a fertilizer. Some animals use it to mark their territories. Historically, aged or fermented urine (known as lant) was also used for gunpowder production, household cleaning, tanning of leather and dye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sterols
Sterol is an organic compound with formula , whose molecule is derived from that of gonane by replacement of a hydrogen atom in position 3 by a hydroxyl group. It is therefore an alcohol of gonane. More generally, any compounds that contain the gonane structure, additional functional groups, and/or modified ring systems derived from gonane are called steroids. Therefore, sterols are a subgroup of the steroids. They occur naturally in most eukaryotes, including plants, animals, and fungi, and can also be produced by some bacteria (however likely with different functions). The most familiar type of animal sterol is cholesterol, which is vital to cell membrane structure, and functions as a precursor to fat-soluble vitamins and steroid hormones. While technically alcohols, sterols are classified by biochemists as lipids ( fats in the broader sense of the term). Types Sterols of plants are called '' phytosterols'' and sterols of animals are called ''zoosterols''. The most impo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenols
In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of one or more hydroxyl groups (— O H) bonded directly to an aromatic hydrocarbon group. The simplest is phenol, . Phenolic compounds are classified as simple phenols or polyphenols based on the number of phenol units in the molecule. Phenols are both synthesized industrially and produced by plants and microorganisms. Properties Acidity Phenols are more acidic than typical alcohols. The acidity of the hydroxyl group in phenols is commonly intermediate between that of aliphatic alcohols and carboxylic acids (their pKa is usually between 10 and 12). Deprotonation of a phenol forms a corresponding negative phenolate ion or phenoxide ion, and the corresponding salts are called phenolates or phenoxides (aryloxides according to the IUPAC Gold Book). Condensation with aldehydes and ketones Phenols are susceptible to Electrophilic aromatic substitutions. Condensation with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estranes
Estrane is a C18 steroid derivative, with a gonane core. ''Estrenes'' are estrane derivatives that contain a double bond, with an example being nandrolone. '' Estratrienes'' (estrins) are estrane derivatives that contain three double bonds, for instance estrin (estra-1,3,5(10)-triene). The estrogen steroid hormones estradiol, estrone, and estriol Estriol (E3), also spelled oestriol, is a steroid, a weak estrogen, and a minor female sex hormone. It is one of three major endogenous estrogens, the others being estradiol and estrone. Levels of estriol in women who are not pregnant are almos ... are estra-1,3,5(10)-trienes. See also * Androstane * Pregnane References Estranes {{Steroid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estrogens
Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal activity: estrone (E1), estradiol (E2), and estriol (E3). Estradiol, an estrane, is the most potent and prevalent. Another estrogen called estetrol (E4) is produced only during pregnancy. Estrogens are synthesized in all vertebrates and some insects. Their presence in both vertebrates and insects suggests that estrogenic sex hormones have an ancient evolutionary history. Quantitatively, estrogens circulate at lower levels than androgens in both men and women. While estrogen levels are significantly lower in males than in females, estrogens nevertheless have important physiological roles in males. Like all steroid hormones, estrogens readily diffuse across the cell membrane. Once inside the cell, they bind to and activate estrogen receptors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
