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Estradiol 3-glucuronide
Estradiol 3-glucuronide (E2-3G), also known as 17β-estradiol 3-(β-D-glucuronide), is a naturally occurring and endogenous estrogen conjugate. It is specifically the C3 glucuronide conjugate of estradiol, the major estrogen in the body. It is formed from estradiol in the liver by UDP-glucuronosyltransferase via attachment of glucuronic acid and is eventually excreted in urine and bile. Similarly to estrogen sulfates like estrone sulfate, estrogen glucuronides have much higher water solubility than do unconjugated estrogens like estradiol. Estrogen glucuronides can be deconjugated into the corresponding free estrogens by β-glucuronidase in tissues that express this enzyme, such as the mammary gland. As a result, estrogen glucuronides have estrogenic activity via conversion into estrogens. Estradiol 3-glucuronide is a positional isomer of estradiol 17β-glucuronide. See also * Catechol estrogen * Estradiol sulfate * Estriol glucuronide * Estriol sulfate * Estrogen conjugat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naturally Occurring
A natural product is a natural compound or substance produced by a living organism—that is, found in nature. In the broadest sense, natural products include any substance produced by life. Natural products can also be prepared by chemical synthesis (both semisynthesis and total synthesis and have played a central role in the development of the field of organic chemistry by providing challenging synthetic targets). The term ''natural product'' has also been extended for commercial purposes to refer to cosmetics, dietary supplements, and foods produced from natural sources without added artificial ingredients. Within the field of organic chemistry, the definition of natural products is usually restricted to organic compounds isolated from natural sources that are produced by the pathways of primary or secondary metabolism. Within the field of medicinal chemistry, the definition is often further restricted to secondary metabolites. Secondary metabolites (or specialized met ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tissue (biology)
In biology, tissue is an assembly of similar cells and their extracellular matrix from the same embryonic origin that together carry out a specific function. Tissues occupy a Biological organisation#Levels, biological organizational level between cell (biology), cells and a complete organ (biology), organ. Accordingly, organs are formed by the functional grouping together of multiple tissues. The English word "tissue" Morphological derivation, derives from the French word "", the past participle of the verb tisser, "to weave". The study of tissues is known as histology or, in connection with disease, as histopathology. Xavier Bichat is considered as the "Father of Histology". Plant histology is Studied Space Shuttle designs, studied in both plant anatomy and Plant physiology, physiology. The classical tools for studying tissues are the Microtome#Applications, paraffin block in which tissue is embedded and then sectioned, the staining, histological stain, and the Microscope, o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estrogens
Estrogen (also spelled oestrogen in British English; see spelling differences) 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. 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 (ERs) which in turn modulate the expression of many genes. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estradiol Esters
Estradiol (E2), also called oestrogen, oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of female reproductive cycles such as estrous and menstrual cycles. Estradiol is responsible for the development of female secondary sexual characteristics such as the breasts, widening of the hips and a female pattern of fat distribution. It is also important in the development and maintenance of female reproductive tissues such as the mammary glands, uterus and vagina during puberty, adulthood and pregnancy. It also has important effects in many other tissues including bone, fat, skin, liver, and the brain. Though estradiol levels in males are much lower than in females, estradiol has important roles in males as well. Apart from humans and other mammals, estradiol is also found in most vertebrates and crustaceans, insects, fish, and other animal species. Estradiol is produced within the follicles of the ovaries and in other ti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipoidal Estradiol
Lipoidal estradiol (LE2) is the variety of endogenous C17β long-chain fatty acid esters of estradiol which are formed as metabolites of estradiol. Important examples of these esters include estradiol arachidonate, estradiol lineolate, estradiol oleate, estradiol palmitate, and estradiol stearate. LE2 are estrogens but do not bind to the estrogen receptor, instead acting as prohormones of estradiol. Relative to estradiol, they have far longer-lasting durations of effect due to their much slower rates of metabolism and clearance. It has been hypothesized that LE2 may serve as a store of estrogen for when estradiol levels become low. LE2 are highly lipophilic and hydrophobic and are found in highest concentrations in adipose tissue and other estrogen-sensitive tissues and in low but detectable concentrations in circulation, with none excreted in urine. They have been referred to as the "endogenous counterparts of the synthetic esters of estrogens" like estradiol valerate and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estrogen Conjugate
An estrogen conjugate is a conjugate of an endogenous estrogen. They occur naturally in the body as metabolites of estrogens and can be reconverted back into estrogens. They serve as a circulating reservoir for estrogen, particularly in the case of orally administered pharmaceutical estradiol. Estrogen conjugates include sulfate and/or glucuronide conjugates of estradiol, estrone, and estriol: * Sulfated: ** Estrone 3-sulfate (E1S) ** Estradiol 3-sulfate (E2S, E2-3S) and estradiol 17β-sulfate (E2-17S) ** Estriol 3-sulfate (E3S) ** Estradiol 3,17β-disulfate (E2DS) * Glucuronidated: ** Estrone 3-glucuronide (E1-G) ** Estradiol 3-glucuronide (E2-3G) and estradiol 17β-glucuronide (E2-17G) ** Estriol 3-glucuronide (E3-3G), estriol 16α-glucuronide (E3-16G) * Mixed: ** Estradiol 3-glucuronide 17β-sulfate (E2-3G-17βS) ** Estradiol 3-sulfate 17β-glucuronide (E2-3S-17βG) ** Estriol 3-sulfate 16α-glucuronide (E3-3S-16G) Estrogen conjugates are conjugated at the C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estriol Sulfate
Estriol sulfate, or estriol 3-sulfate, is a conjugated metabolite of estriol that is present in high quantities during pregnancy. It is formed from estriol in the liver and is eventually excreted in the urine by the kidneys. It has much higher water solubility than does estriol. Estriol sulfate is the second most prevalent conjugated metabolite of estriol during pregnancy; 35 to 46% is estriol glucuronide and 15 to 22% is estriol 3-sulfate, while the double conjugate estriol sulfate glucuronide also occurs. Estriol sulfate was a component, along with estriol glucuronide, of the early pharmaceutical estrogens Progynon and Emmenin. See also * Catechol estrogen * Estradiol glucuronide * Estradiol sulfate * Estrogen conjugate * Estrone glucuronide * Estrone sulfate * Lipoidal estradiol Lipoidal estradiol (LE2) is the variety of endogenous C17β long-chain fatty acid esters of estradiol which are formed as metabolites of estradiol. Important examples of these esters include estra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estriol Glucuronide
Estriol glucuronide (E3G), or oestriol glucuronide, also known as estriol monoglucuronide, as well as estriol 16α-β-D-glucosiduronic acid, is a natural, steroidal estrogen and the glucuronic acid (β-D-glucopyranuronic acid) conjugate of estriol. It occurs in high concentrations in the urine of pregnant women as a reversibly formed metabolite of estriol. Estriol glucuronide is a prodrug of estriol, and was the major component of Progynon and Emmenin, estrogenic products manufactured from the urine of pregnant women that were introduced in the 1920s and 1930s and were the first orally active estrogens. Emmenin was succeeded by Premarin ( conjugated equine estrogens), which is sourced from the urine of pregnant mares and was introduced in 1941. Premarin replaced Emmenin because it was easier and less expensive to produce. Estrogen glucuronides can be deglucuronidated into the corresponding free estrogens by β-glucuronidase in tissues that express this enzyme, such as the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estradiol Sulfate
Estradiol sulfate (E2S), or 17β-estradiol 3-sulfate, is a natural, endogenous steroid and an estrogen ester. E2S itself is biologically inactive, but it can be converted by steroid sulfatase (also called estrogen sulfatase) into estradiol, which is a potent estrogen. Simultaneously, estrogen sulfotransferases convert estradiol to E2S, resulting in an equilibrium between the two steroids in various tissues. Estrone and E2S are the two immediate metabolic sources of estradiol. E2S can also be metabolized into estrone sulfate (E1S), which in turn can be converted into estrone and estradiol. Circulating concentrations of E2S are much lower than those of E1S. High concentrations of E2S are present in breast tissue, and E2S has been implicated in the biology of breast cancer via serving as an active reservoir of estradiol. As the sodium salt sodium estradiol sulfate, E2S is present as a minor constituent (0.9%) of conjugated equine estrogens (CEEs), or Premarin. It effectively functio ... [...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 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estradiol 17β-glucuronide
Estradiol glucuronide, or estradiol 17β-D-glucuronide, is a conjugated metabolite of estradiol. It is formed from estradiol in the liver by UDP-glucuronyltransferase via attachment of glucuronic acid and is eventually excreted in the urine by the kidneys. It has much higher water solubility than does estradiol. Glucuronides are the most abundant estrogen conjugates. When exogenous estradiol is administered orally, it is subject to extensive first-pass metabolism (95%) in the intestines and liver. A single administered dose of estradiol is absorbed 15% as estrone, 25% as estrone sulfate, 25% as estradiol glucuronide, and 25% as estrone glucuronide. Formation of estrogen glucuronide conjugates is particularly important with oral estradiol as the percentage of estrogen glucuronide conjugates in circulation is much higher with oral ingestion than with parenteral estradiol. Estradiol glucuronide can be converted back into estradiol, and a large circulating pool of estrogen glucur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Positional Isomer
In chemistry, a structural isomer (or constitutional isomer in the IUPAC nomenclature) of a compound is a compound that contains the same number and type of atoms, but with a different connectivity (i.e. arrangement of bonds) between them. The term metamer was formerly used for the same concept. For example, butanol , methyl propyl ether , and diethyl ether have the same molecular formula but are three distinct structural isomers. The concept applies also to polyatomic ions with the same total charge. A classical example is the cyanate ion and the fulminate ion . It is also extended to ionic compounds, so that (for example) ammonium cyanate and urea are considered structural isomers,William F. Bynum, E. Janet Browne, Roy Porter (2014)''Dictionary of the History of Science'' page 218. and so are methylammonium formate and ammonium acetate . Structural isomerism is the most radical type of isomerism. It is opposed to stereoisomerism, in which the atoms and bonding s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
