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Tetrahydropalmatine
Tetrahydropalmatine (THP) is an isoquinoline alkaloid found in several different plant species, mainly in the genus ''Corydalis'' ( Yan Hu Suo), but also in other plants such as '' Stephania rotunda''. These plants have traditional uses in Chinese herbal medicine. The pharmaceutical industry has synthetically produced the more potent enantiomer Levo-tetrahydropalmatine (Levo-THP; technically ''l''-THP, often written L-THP), which has been marketed worldwide under different brand names as an alternative to anxiolytic and sedative drugs of the benzodiazepine group and analgesics such as opiates. It is also sold as a dietary supplement. In 1940, a Vietnamese scientist Sang Dinh Bui extracted an alkaloid from the root of '' Stephania rotunda'' with the yield of 1.2–1.5% and he named this compound rotundin. From 1950 to 1952, two Indian scientists studied and extracted from ''Stephania glabra'' another alkaloid named hyndanrine. In 1965, the structure of rotundine and hyndari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoquinoline Alkaloids
Isoquinoline alkaloids are natural products of the group of alkaloids, which are chemically derived from isoquinoline. They form the largest group among the alkaloids. Isoquinoline alkaloids can be further classified based on their different chemical basic structures. The most common structural types are the benzylisoquinolines and the aporphines.Bettina Ruff: ''Chemische und biochemische Methoden zur stereoselektiven Synthese von komplexen Naturstoffen.'' Verlag Logos, Berlin 2012, , S. 8. () According to current knowledge, a total of about 2500 isoquinoline alkaloids are known nowadays, which are mainly formed by plants.Jennifer M. Finefield, David H. Sherman, Martin Kreitman, Robert M. Williams: ''Enantiomere Naturstoffe: Vorkommen und Biogenese.'' In: ''Angewandte Chemie.'' Wiley-VCH, Weinheim 2012, doi:10.1002/ange.201107204, S. 4905–4915. Known examples Morphin - Morphine.svg, Morphine Codein - Codeine.svg, Codeine Papaverin - Papaverine.svg, Papaverine Berbe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatotoxicity
Hepatotoxicity (from ''hepatic toxicity'') implies chemical-driven liver damage. Drug-induced liver injury (DILI) is a cause of acute and chronic liver disease caused specifically by medications and the most common reason for a drug to be withdrawn from the market after approval. The liver plays a central role in transforming and clearing chemicals and is susceptible to the toxicity from these agents. Certain medicinal agents, when taken in overdoses (e.g. acetaminophen, paracetamol) and sometimes even when introduced within therapeutic ranges (e.g. halothane), may injure the organ. Other chemical agents, such as those used in laboratories and industries, natural chemicals (e.g., alpha-amanitin), and herbal remedies (two prominent examples being kava, though the causal mechanism is unknown, and comfrey, through pyrrolizidine alkaloid content) can also induce hepatotoxicity. Chemicals that cause liver injury are called hepatotoxins. More than 900 drugs have been implicated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dopamine Receptor D4
The dopamine receptor D4 is a dopamine D2-like G protein-coupled receptor encoded by the gene on chromosome 11 at 11p15.5. The structure of DRD4 has been reported in complex with the antipsychotic drug nemonapride. As with other dopamine receptor subtypes, the D4 receptor is activated by the neurotransmitter dopamine. It is linked to many neurological and psychiatric conditions including schizophrenia and bipolar disorder, ADHD, addictive behaviors, Parkinson's disease, and eating disorders such as anorexia nervosa. A weak association has been drawn between DRD4 and borderline personality disorder. It is also a target for drugs which treat schizophrenia and Parkinson's disease. The D4 receptor is considered to be D2-like in which the activated receptor inhibits the enzyme adenylate cyclase, thereby reducing the intracellular concentration of the second messenger cyclic AMP. Genetics The human protein is coded by the ''DRD4'' on chromosome 11 located in 11p15.5. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dopamine Receptor D3
Dopamine receptor D3 is a protein that in humans is encoded by the ''DRD3'' gene. This gene encodes the D3 subtype of the dopamine receptor. The D3 subtype inhibits adenylyl cyclase through inhibitory G-proteins. This receptor is expressed in phylogenetically older regions of the brain, suggesting that this receptor plays a role in cognitive and emotional functions. It is a target for drugs which treat schizophrenia, drug addiction, and Parkinson's disease. Alternative splicing of this gene results in multiple transcript variants that would encode different isoforms, although some variants may be subject to nonsense-mediated decay (NMD). On a side note, it is also the Dopamine Receptor sub-type possessing the highest binding affinity for Dopamine itself and may explain why non- ergoline Dopamine Agonists are D3-preferring Function Alpha-synuclein (α-Syn) aggregation via Lewy bodies inclusion, a pathogenic signature exclusively present in PD patients, is decreased by D3 ago ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dopamine Receptor D2
Dopamine receptor D2, also known as D2R, is a protein that, in humans, is encoded by the ''DRD2'' gene. After work from Paul Greengard's lab had suggested that dopamine receptors were the site of action of antipsychotic drugs, several groups, including those of Solomon H. Snyder and Philip Seeman used a radiolabeled antipsychotic drug to identify what is now known as the dopamine D2 receptor. The dopamine D2 receptor is the main receptor for most antipsychotic drugs. The structure of DRD2 in complex with the atypical antipsychotic risperidone has been determined. Function D2 receptors are coupled to Gi subtype of G protein. This G protein-coupled receptor inhibits adenylyl cyclase activity. In mice, regulation of D2R surface expression by the neuronal calcium sensor-1 (NCS-1) in the dentate gyrus is involved in exploration, synaptic plasticity and memory formation. Studies have shown potential roles for D2R in retrieval of fear memories in the prelimbic cortex and in d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dopamine Receptor D1
Dopamine receptor D1, also known as DRD1. It is one of the two types of D1-like receptor family receptors D1 and D5. It is a protein that in humans is encoded by the DRD1 gene. Tissue distribution D1 receptors are the most abundant kind of dopamine receptor in the central nervous system. Northern blot and in situ hybridization show that the gene expression, mRNA expression of DRD1 is highest in the dorsal striatum (caudate nucleus, caudate and putamen) and ventral striatum (nucleus accumbens and olfactory tubercle). Lower levels occur in the basolateral amygdala, cerebral cortex, septum, thalamus, and hypothalamus. The DRD1 gene expresses primarily in the caudate putamen in humans, and in the caudate putamen, the nucleus accumbens and the olfactory tubercle in mouse. Structure The dopamine receptor D1 (D1R) is a Gs-coupled GPCR characterized by a canonical seven-transmembrane (TM) helical domain, with a ligand-binding pocket located Extracellular space, extracellularl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reverse Transcriptase
A reverse transcriptase (RT) is an enzyme used to convert RNA genome to DNA, a process termed reverse transcription. Reverse transcriptases are used by viruses such as HIV and hepatitis B to replicate their genomes, by retrotransposon mobile genetic elements to proliferate within the host genome, and by eukaryotic cells to extend the telomeres at the ends of their linear chromosomes. The process does not violate the flows of genetic information as described by the classical central dogma, but rather expands it to include transfers of information from RNA to DNA. Retroviral RT has three sequential biochemical activities: RNA-dependent DNA polymerase activity, ribonuclease H (RNase H), and DNA-dependent DNA polymerase activity. Collectively, these activities enable the enzyme to convert single-stranded RNA into double-stranded cDNA. In retroviruses and retrotransposons, this cDNA can then integrate into the host genome, from which new RNA copies can be made via host-cell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tissue Factor
Tissue factor, also called platelet tissue factor or Coagulation factor III, is a protein present in subendothelial tissue and leukocytes which plays a major role in coagulation and, in humans, is encoded by ''F3'' gene. Its role in the blood clotting is the initiation of thrombin formation from the zymogen prothrombin. Thromboplastin defines the cascade that leads to the activation of factor X—the tissue factor pathway. In doing so, it has replaced the previously named extrinsic pathway in order to eliminate ambiguity. Function The F3 gene encodes tissue factor also known as coagulation factor III, which is a cell surface glycoprotein. This factor enables cells to initiate the blood coagulation cascades, and it functions as the high-affinity receptor for the coagulation factor VII. The resulting complex provides a catalytic event that is responsible for initiation of the coagulation protease cascades by specific limited proteolysis. Unlike the other cofactors of these pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnesium Trisilicate
Magnesium trisilicate is an inorganic compound that is used as a food additive. The additive is frequently used by fast food chains to absorb fatty acids and extract impurities formed while frying edible oils. It has good acid neutralizing properties, but the reaction appears too slow to serve as an effective non-prescription antacid. Health effects On March 12, 2007, Chinese health authorities halted the use of magnesium trisilicate at Shaanxi Province KFC franchises, suspecting it to be a possible carcinogen A carcinogen () is any agent that promotes the development of cancer. Carcinogens can include synthetic chemicals, naturally occurring substances, physical agents such as ionizing and non-ionizing radiation, and biologic agents such as viruse .... As a response, China's Ministry of Health conducted tests at six outlets of KFC. The results showed chemicals in the cooking process at KFC restaurants in the country were not harmful. The Ministry of Health said tests show ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium Hydroxide
Aluminium hydroxide, , is found as the mineral gibbsite (also known as hydrargillite) and its three much rarer polymorphs: bayerite, doyleite, and nordstrandite. Aluminium hydroxide is amphoteric, i.e., it has both basic and acidic properties. Closely related are aluminium oxide hydroxide, AlO(OH), and aluminium oxide or alumina (), the latter of which is also amphoteric. These compounds together are the major components of the aluminium ore bauxite. Aluminium hydroxide also forms a gelatinous precipitate in water. Structure is built up of double layers of hydroxyl groups with aluminium ions occupying two-thirds of the octahedral holes between the two layers. Four polymorphs are recognized. All feature layers of octahedral aluminium hydroxide units, with hydrogen bonds between the layers. The polymorphs differ in terms of the stacking of the layers. All forms of crystals are hexagonal : * gibbsite is also known as γ- or α- * bayerite is also known as α- or ''β ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitamin U
''S''-Methylmethionine (SMM) is a derivative of methionine with the chemical formula ( CH3)2S+CH2CH2CH(NH3+)CO2−. This cation is a naturally-occurring intermediate in many biosynthetic pathways owing to the sulfonium functional group. It is biosynthesized from L-methionine and ''S''-adenosylmethionine by the enzyme methionine ''S''-methyltransferase. ''S''-methylmethionine is particularly abundant in plants, being more abundant than methionine. ''S''-Methylmethionine is sometimes referred to as ''vitamin U'', but it is not considered a true vitamin. The term was coined in 1950 by Garnett Cheney for uncharacterized anti-ulcerogenic factors in raw cabbage juice that may help speed healing of peptic ulcers. Biosynthesis and biochemical function ''S''-Methylmethionine arises via the methylation of methionine by ''S''-adenosyl methionine (SAM). The coproduct is ''S''-adenosyl homocysteine. The biological roles of ''S''-methylmethionine are not well understood. Speculated rol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Medical Products Administration
The National Medical Products Administration (NMPA; ) is a national bureau responsible for drug supervision under the State Council of China and is managed by the State Administration for Market Regulation. History The agency had multiple former names, including China Food and Drug Administration and State Food and Drug Administration. The National Medical Products Administration was founded on the basis of the former State Food and Drug Administration (SFDA). In March 2013, the former regulatory body was rebranded and restructured as the China Food and Drug Administration, elevating it to a ministerial-level agency. In 2018, as part of China's 2018 government administration overhaul, the name was changed to 'National Medical Products Administration' and merged into the newly created State Administration for Market Regulation. The headquarters are in Xicheng, Beijing. In its first incarnation as the CFDA, the NMPA replaced a large group of overlapping regulators with an ent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
