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Epimer
In stereochemistry, an epimer is one of a pair of diastereomers. The two epimers have opposite configuration at only one stereogenic center out of at least two. All other stereogenic centers in the molecules are the same in each. Epimerization is the interconversion of one epimer to the other epimer. Doxorubicin and epirubicin are two epimers that are used as drugs. Examples The stereoisomers β-D- glucopyranose and β-D- mannopyranose are epimers because they differ only in the stereochemistry at the C-2 position. The hydroxy group in β-D-glucopyranose is equatorial (in the "plane" of the ring), while in β-D-mannopyranose the C-2 hydroxy group is axial (up from the "plane" of the ring). These two molecules are epimers but, because they are not mirror images of each other, are not enantiomers. (Enantiomers have the same name, but differ in D and L classification.) They are also not sugar anomers, since it is not the anomeric carbon involved in the stereochemistry. Simila ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RENBP
N-acylglucosamine 2-epimerase is an enzyme that in humans is encoded by the ''RENBP'' gene. The gene product inhibits renin activity by forming a dimer with renin, a complex known as high molecular weight renin. The encoded protein contains a leucine zipper domain, which is essential for its dimerization with renin. The gene product can catalyze the interconversion of N-acetylglucosamine ''N''-Acetylglucosamine (GlcNAc) is an amide derivative of the monosaccharide glucose. It is a secondary amide between glucosamine and acetic acid. It is significant in several biological systems. It is part of a biopolymer in the bacterial ... to N-acetylmannosamine, indicating that it is a GlcNAc 2-epimerase. Transcript variants utilizing alternative promoters have been described in the literature. References Further reading * * * * * * * * * * * * * * * * * * {{gene-X-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipoxin
A lipoxin (LX or Lx), an acronym for lipoxygenase interaction product, is a bioactive autacoid metabolite of arachidonic acid made by various cell types. They are categorized as nonclassic eicosanoids and members of the specialized pro-resolving mediators (SPMs) family of polyunsaturated fatty acid (PUFA) metabolites. Like other SPMs, LXs form during, and then act to resolve, inflammatory responses. Initially, two lipoxins were identified, lipoxin A4 (LXA4) and LXB4, but more recent studies have identified epimers of these two LXs: the epi-lipoxins, 15-epi-LXA4 and 15-epi-LXB4 respectively. History LXA4 and LXB4 were first described by Serhan, Hamberg, and the Nobel laurate Samuelsson in 1984. They reported that human blood neutrophils, when stimulated, make these two lipoxins and that neutrophils, when stimulated by either of the LXs, mounted superoxide anion (O2−) generation and degranulation responses. Both responses are considered to be pro-inflammatory in that, whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipoxin B4
A lipoxin (LX or Lx), an acronym for lipoxygenase interaction product, is a bioactive autacoid metabolite of arachidonic acid made by various cell types. They are categorized as nonclassic eicosanoids and members of the specialized pro-resolving mediators (SPMs) family of polyunsaturated fatty acid (PUFA) metabolites. Like other SPMs, LXs form during, and then act to resolve, inflammatory responses. Initially, two lipoxins were identified, lipoxin A4 (LXA4) and LXB4, but more recent studies have identified epimers of these two LXs: the epi-lipoxins, 15-epi-LXA4 and 15-epi-LXB4 respectively. History LXA4 and LXB4 were first described by Serhan, Hamberg, and the Nobel laurate Samuelsson in 1984. They reported that human blood neutrophils, when stimulated, make these two lipoxins and that neutrophils, when stimulated by either of the LXs, mounted superoxide anion (O2−) generation and degranulation responses. Both responses are considered to be pro-inflammatory in that, while ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta-D-glucopyranose
Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using energy from sunlight, where it is used to make cellulose in cell walls, the most abundant carbohydrate in the world. In energy metabolism, glucose is the most important source of energy in all organisms. Glucose for metabolism is stored as a polymer, in plants mainly as starch and amylopectin, and in animals as glycogen. Glucose circulates in the blood of animals as blood sugar. The naturally occurring form of glucose is -glucose, while -glucose is produced synthetically in comparatively small amounts and is less biologically active. Glucose is a monosaccharide containing six carbon atoms and an aldehyde group, and is therefore an aldohexose. The glucose molecule can exist in an open-chain (acyclic) as well as ring (cyclic) form. Glucos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucopyranose
Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using energy from sunlight, where it is used to make cellulose in cell walls, the most abundant carbohydrate in the world. In energy metabolism, glucose is the most important source of energy in all organisms. Glucose for metabolism is stored as a polymer, in plants mainly as starch and amylopectin, and in animals as glycogen. Glucose circulates in the blood of animals as blood sugar. The naturally occurring form of glucose is -glucose, while -glucose is produced synthetically in comparatively small amounts and is less biologically active. Glucose is a monosaccharide containing six carbon atoms and an aldehyde group, and is therefore an aldohexose. The glucose molecule can exist in an open-chain (acyclic) as well as ring (cyclic) form. Glucos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galactose
Galactose (, '' galacto-'' + '' -ose'', "milk sugar"), sometimes abbreviated Gal, is a monosaccharide sugar that is about as sweet as glucose, and about 65% as sweet as sucrose. It is an aldohexose and a C-4 epimer of glucose. A galactose molecule linked with a glucose molecule forms a lactose molecule. Galactan is a polymeric form of galactose found in hemicellulose, and forming the core of the galactans, a class of natural polymeric carbohydrates. D-Galactose is also known as brain sugar since it is a component of glycoproteins (oligosaccharide-protein compounds) found in Nerve tissue, nerve tissue. Etymology The word ''galactose'' was coined by Charles Weissman in the mid-19th century and is derived from Greek ''galaktos'' (of milk) and the generic chemical suffix for sugars ''-ose''. The etymology is comparable to that of the word '' lactose'' in that both contain roots meaning "milk sugar". Lactose is a disaccharide of galactose plus glucose. Structure and isomerism Gal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diastereomer
In stereochemistry, diastereomers (sometimes called diastereoisomers) are a type of stereoisomer. Diastereomers are defined as non-mirror image, non-identical stereoisomers. Hence, they occur when two or more stereoisomers of a compound have different configurations at one or more (but not all) of the equivalent (related) stereocenters and are not mirror images of each other. When two diastereoisomers differ from each other at only one stereocenter, they are epimers. Each stereocenter gives rise to two different configurations and thus typically increases the number of stereoisomers by a factor of two. Diastereomers differ from enantiomers in that the latter are pairs of stereoisomers that differ in all stereocenters and are therefore mirror images of one another. Enantiomers of a compound with more than one stereocenter are also diastereomers of the other stereoisomers of that compound that are not their mirror image (that is, excluding the opposing enantiomer). Diastereomers h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myo-inositol
Inositol, or more precisely ''myo''-inositol, is a carbocyclic sugar that is abundant in the brain and other mammalian tissues; it mediates cell signal transduction in response to a variety of hormones, neurotransmitters, and growth factors and participates in osmoregulation. It is a sugar alcohol with half the sweetness of sucrose (table sugar). It is made naturally in the human body from glucose. A human kidney makes about two grams per day. Other tissues synthesize it too, and the highest concentration is in the brain, where it plays an important role by making other neurotransmitters and some steroid hormones bind to their receptors. Inositol is promoted as a dietary supplement in the management of polycystic ovary syndrome (PCOS). However, there is only evidence of very low quality for its efficacy in increasing fertility for IVF in women with PCOS. Overview ''myo''-Inositol plays an important role as the structural basis for a number of secondary messengers in eukaryotic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diastereomer
In stereochemistry, diastereomers (sometimes called diastereoisomers) are a type of stereoisomer. Diastereomers are defined as non-mirror image, non-identical stereoisomers. Hence, they occur when two or more stereoisomers of a compound have different configurations at one or more (but not all) of the equivalent (related) stereocenters and are not mirror images of each other. When two diastereoisomers differ from each other at only one stereocenter, they are epimers. Each stereocenter gives rise to two different configurations and thus typically increases the number of stereoisomers by a factor of two. Diastereomers differ from enantiomers in that the latter are pairs of stereoisomers that differ in all stereocenters and are therefore mirror images of one another. Enantiomers of a compound with more than one stereocenter are also diastereomers of the other stereoisomers of that compound that are not their mirror image (that is, excluding the opposing enantiomer). Diastereomers h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inositol
Inositol, or more precisely ''myo''-inositol, is a carbocyclic sugar that is abundant in the brain and other mammalian tissues; it mediates cell signal transduction in response to a variety of hormones, neurotransmitters, and growth factors and participates in osmoregulation. It is a sugar alcohol with half the sweetness of sucrose (table sugar). It is made naturally in the human body from glucose. A human kidney makes about two grams per day. Other tissues synthesize it too, and the highest concentration is in the brain, where it plays an important role by making other neurotransmitters and some steroid hormones bind to their receptors. Inositol is promoted as a dietary supplement in the management of polycystic ovary syndrome (PCOS). However, there is only evidence of very low quality for its efficacy in increasing fertility for IVF in women with PCOS. Overview ''myo''-Inositol plays an important role as the structural basis for a number of secondary messengers in eukaryotic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anomer
In carbohydrate chemistry, a pair of anomers () is a pair of near-identical stereoisomers that differ at only the anomeric carbon, the carbon that bears the aldehyde or ketone functional group in the sugar's open-chain form. However, in order for anomers to exist, the sugar must be in its cyclic form, since in open-chain form, the anomeric carbon is planar and thus achiral. More formally stated, then, an anomer is an epimer at the hemiacetal/hemiketal carbon in a cyclic saccharide. Anomerization is the process of conversion of one anomer to the other. As is typical for stereoisomeric compounds, different anomers have different physical properties, melting points and specific rotations. Nomenclature Two anomers are designated alpha (α) or beta (β), according to the configurational relationship between the ''anomeric centre'' and the ''anomeric reference atom'', hence they are relative stereodescriptors. The anomeric centre in hemiacetals is the anomeric carbon C-1; in hemi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anomeric Carbon
In carbohydrate chemistry, a pair of anomers () is a pair of near-identical stereoisomers that differ at only the anomeric carbon, the carbon that bears the aldehyde or ketone functional group in the sugar's open-chain form. However, in order for anomers to exist, the sugar must be in its cyclic form, since in open-chain form, the anomeric carbon is planar and thus achiral. More formally stated, then, an anomer is an epimer at the hemiacetal/hemiketal carbon in a cyclic saccharide. Anomerization is the process of conversion of one anomer to the other. As is typical for stereoisomeric compounds, different anomers have different physical properties, melting points and specific rotations. Nomenclature Two anomers are designated alpha (α) or beta (β), according to the configurational relationship between the ''anomeric centre'' and the ''anomeric reference atom'', hence they are relative stereodescriptors. The anomeric centre in hemiacetals is the anomeric carbon C-1; in hemi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
