|
Betaines
A betaine () in chemistry is any neutral chemical compound with a positively charged cationic functional group that bears no hydrogen atom, such as a quaternary ammonium or phosphonium cation (generally: onium ions), and with a negatively charged functional group, such as a carboxylate group that may not be adjacent to the cationic site. Historically, the term was reserved for trimethylglycine (TMG), which is involved in methylation reactions and detoxification of homocysteine. This is a modified amino acid consisting of glycine with three methyl groups serving as methyl donor for various metabolic pathways. Pronunciation The pronunciation of the compound reflects its origin and first isolation from sugar ''beets'' (''Beta vulgaris'' subsp. ''vulgaris''), and does not derive from the Greek letter beta (β). It is commonly pronounced ''beta-INE'' or ''BEE-tayn''. Glycine betaine The original betaine, ''N'',''N'',''N''-trimethylglycine, was named after its discovery in sug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zwitterion
In chemistry, a zwitterion ( ; ), also called an inner salt or dipolar ion, is a molecule that contains an equal number of positively and negatively charged functional groups. : (1,2- dipolar compounds, such as ylides, are sometimes excluded from the definition.) Some zwitterions, such as amino acid zwitterions, are in chemical equilibrium with an uncharged "parent" molecule. Betaines are zwitterions that cannot isomerize to an all-neutral form, such as when the positive charge is located on a quaternary ammonium group. Similarly, a molecule containing a phosphonium group and a carboxylate group cannot isomerize. Amino acids Tautomerism of amino acids follows this stoichiometry: : The ratio of the concentrations of the two species in solution is independent of pH. It has been suggested, on the basis of theoretical analysis, that the zwitterion is stabilized in aqueous solution by hydrogen bonding with solvent water molecules. Analysis of neutron diffraction data for g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Betaine Formula V
A betaine () in chemistry is any neutral chemical compound with a positively charged cationic functional group that bears no hydrogen atom, such as a quaternary ammonium or phosphonium cation (generally: onium ions), and with a negatively charged functional group, such as a carboxylate group that may not be adjacent to the cationic site. Historically, the term was reserved for trimethylglycine (TMG), which is involved in methylation reactions and detoxification of homocysteine. This is a modified amino acid consisting of glycine with three methyl groups serving as methyl donor for various metabolic pathways. Pronunciation The pronunciation of the compound reflects its origin and first isolation from sugar ''beets'' (''Beta vulgaris'' subsp. ''vulgaris''), and does not derive from the Greek letter beta (β). It is commonly pronounced ''beta-INE'' or ''BEE-tayn''. Glycine betaine The original betaine, ''N'',''N'',''N''-trimethylglycine, was named after its discovery in su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesoionic
In chemistry, mesoionic compounds are one in which a heterocyclic structure is dipolar and where both the negative and the positive charges are delocalized. A completely uncharged structure cannot be written and mesoionic compounds cannot be represented satisfactorily by any one mesomeric structure. Mesoionic compounds are a subclass of betaines. Examples are sydnones and sydnone imines (e.g. the stimulant mesocarb), münchnones, and mesoionic carbenes. The formal positive charge is associated with the ring atoms and the formal negative charge is associated either with ring atoms or an exocyclic nitrogen or other atom. These compounds are stable zwitterionic compounds and belong to nonbenzenoid aromatic In organic chemistry, aromaticity is a chemical property describing the way in which a conjugated system, conjugated ring of unsaturated bonds, lone pairs, or empty orbitals exhibits a stabilization stronger than would be expected from conjugati ...s. See also * Mesom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trimethylglycine
Trimethylglycine is an amino acid derivative with the formula . A colorless, water-soluble solid, it occurs in plants. Trimethylglycine is a zwitterion: the molecule contains both a quaternary ammonium cation, quaternary ammonium group and a carboxylate group. Trimethylglycine was the first betaine discovered; originally it was simply called betaine because it was discovered in sugar beets (''Beta vulgaris'' subsp. ''vulgaris''). Several other betaines are now known. Medical uses Betaine, sold under the brand name Cystadane, is indicated for the adjunctive treatment of homocystinuria, involving deficiencies or defects in cystathionine beta-synthase (CBS), 5,10-methylene-tetrahydrofolate reductase (MTHFR), or cobalamin cofactor metabolism (cbl). The most common side effect is elevated levels of methionine in the blood. The EU has authorized the health claim that betaine "contributes to normal homocysteine metabolism.". Biological function Biosynthesis In most organisms, gly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesomeric Betaine
Mesomeric betaines are dipolar heterocyclic compounds in which both the negative and the positive charges are delocalized. Examples are mesoionic compounds and heteropentalenes (e.g. diazapentalenes). Heteropentalenes are not mesoionic In chemistry, mesoionic compounds are one in which a heterocyclic structure is dipolar and where both the negative and the positive charges are delocalized. A completely uncharged structure cannot be written and mesoionic compounds cannot be repr .... References Heterocyclic compounds Aromatic compounds {{aromatic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trimethylglycine
Trimethylglycine is an amino acid derivative with the formula . A colorless, water-soluble solid, it occurs in plants. Trimethylglycine is a zwitterion: the molecule contains both a quaternary ammonium cation, quaternary ammonium group and a carboxylate group. Trimethylglycine was the first betaine discovered; originally it was simply called betaine because it was discovered in sugar beets (''Beta vulgaris'' subsp. ''vulgaris''). Several other betaines are now known. Medical uses Betaine, sold under the brand name Cystadane, is indicated for the adjunctive treatment of homocystinuria, involving deficiencies or defects in cystathionine beta-synthase (CBS), 5,10-methylene-tetrahydrofolate reductase (MTHFR), or cobalamin cofactor metabolism (cbl). The most common side effect is elevated levels of methionine in the blood. The EU has authorized the health claim that betaine "contributes to normal homocysteine metabolism.". Biological function Biosynthesis In most organisms, gly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Disorder
A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosome abnormality. Although polygenic disorders are the most common, the term is mostly used when discussing disorders with a single genetic cause, either in a gene or chromosome. The mutation responsible can occur spontaneously before embryonic development (a ''de novo'' mutation), or it can be inherited from two parents who are carriers of a faulty gene ( autosomal recessive inheritance) or from a parent with the disorder (autosomal dominant inheritance). When the genetic disorder is inherited from one or both parents, it is also classified as a hereditary disease. Some disorders are caused by a mutation on the X chromosome and have X-linked inheritance. Very few disorders are inherited on the Y chromosome or mitochondrial DNA (due to their size). There are well over 6,000 known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymerase Chain Reaction
The polymerase chain reaction (PCR) is a method widely used to make millions to billions of copies of a specific DNA sample rapidly, allowing scientists to amplify a very small sample of DNA (or a part of it) sufficiently to enable detailed study. PCR was invented in 1983 by American biochemist Kary Mullis at Cetus Corporation. Mullis and biochemist Michael Smith (chemist), Michael Smith, who had developed other essential ways of manipulating DNA, were jointly awarded the Nobel Prize in Chemistry in 1993. PCR is fundamental to many of the procedures used in genetic testing and research, including analysis of Ancient DNA, ancient samples of DNA and identification of infectious agents. Using PCR, copies of very small amounts of DNA sequences are exponentially amplified in a series of cycles of temperature changes. PCR is now a common and often indispensable technique used in medical laboratory research for a broad variety of applications including biomedical research and forensic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Food Safety Authority
The European Food Safety Authority (EFSA) is the agency of the European Union (EU) that provides independent scientific advice and communicates on existing and emerging risks associated with the food chain. EFSA was established in February 2002 in Parma, Italy. It had a yearly budget of €118.6 million, and a total staff of 542 as of 2021. The work of EFSA covers all matters with a direct or indirect impact on food and feed safety, including animal health and welfare, plant protection and plant health and nutrition. EFSA supports the European Commission, the European Parliament and EU member states in taking effective and timely risk management decisions that ensure the protection of the health of European consumers and the safety of the food and feed chain. EFSA also communicates to the public in an open and transparent way on all matters within its remit. Structure Based on a regulation of 2002, the EFSA is composed of four bodies: * Management Board * Executive Direc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prescription Drug
A prescription drug (also prescription medication, prescription medicine or prescription-only medication) is a pharmaceutical drug that is permitted to be dispensed only to those with a medical prescription. In contrast, over-the-counter drugs can be obtained without a prescription. The reason for this difference in substance control is the potential scope of misuse, from drug abuse to practising medicine without a license and without sufficient education. Different jurisdictions have different definitions of what constitutes a prescription drug. In North America, , usually printed as "Rx", is used as an abbreviation of the word "prescription". It is a contraction of the Latin word "''recipe''" (an imperative form of "recipere") meaning "take". Prescription drugs are often dispensed together with a monograph (in Europe, a Patient Information Leaflet or PIL) that gives detailed information about the drug. The use of prescription drugs has been increasing since the 1960s. Regul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cocamidopropyl Betaine
Cocamidopropyl betaine (CAPB) is a mixture of closely related organic compounds derived from coconut oil and dimethylaminopropylamine. CAPB is available as a viscous pale yellow solution and it is used as a surfactant in personal care products and animal husbandry. The name reflects that the major part of the molecule, the lauric acid group, is derived from coconut oil. Cocamidopropyl betaine to a significant degree has replaced cocamide DEA. Production Despite the name cocamidopropyl betaine, the molecule is not synthesized from betaine. Instead it is produced in a two-step manner, beginning with the reaction of dimethylaminopropylamine (DMAPA) with fatty acids from coconut or palm kernel oil ( lauric acid, or its methyl ester, is the main constituent). The primary amine in DMAPA is more reactive than the tertiary amine, leading to its selective addition to form an amide. In the second step chloroacetic acid reacts with the remaining tertiary amine to form a quaternary am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homocystinuria
Homocystinuria (HCU) is an inherited disorder of the metabolism of the amino acid methionine due to a deficiency of cystathionine beta synthase or methionine synthase. It is an inherited autosomal recessive trait, which means a child needs to inherit a copy of the defective gene from both parents to be affected. Symptoms of homocystinuria can also be caused by a deficiency of vitamins B6, B12, or folate. Signs and symptoms This defect leads to a multi-systemic disorder of the connective tissue, muscles, central nervous system (CNS), and cardiovascular system. Homocystinuria represents a group of hereditary metabolic disorders characterized by an accumulation of the amino acid homocysteine in the serum and an increased excretion of homocysteine in the urine. Infants appear to be normal and early symptoms, if any are present, are vague. Signs and symptoms of homocystinuria that may be seen include the following: Cause It is usually caused by the deficiency of the enzyme cyst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
