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Oleanolic Acid
Oleanolic acid or oleanic acid is a naturally occurring pentacyclic triterpenoid related to betulinic acid. It is widely distributed in food and plants where it exists as a free acid or as an aglycone of triterpenoid saponins. Natural occurrence Oleanolic acid can be found in olive oil, ''Phytolacca americana'' (American pokeweed), and ''Syzygium'' spp, garlic, etc. It was first studied and isolated from several plants, including ''Olea europaea'' (leaves, fruit), ''Rosa woodsii'' (leaves), '' Prosopis glandulosa'' (leaves and twigs), '' Phoradendron juniperinum'' (whole plant), '' Syzygium claviflorum'' (leaves), '' Hyptis capitata'' (whole plant), '' Mirabilis jalapa'') and '' Ternstroemia gymnanthera'' (aerial part). Other ''Syzygium'' species including java apple (''Syzygium samarangense'') and rose apples contain it, as does ''Ocimum tenuiflorum'' (holy basil). Biosynthesis of oleanolic acids Oleanolic acid biosynthesis starts with mevalonate to create squalene. Squa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triterpenoid
Triterpenes are a class of chemical compounds composed of three terpene units with the molecular formula C30H48; they may also be thought of as consisting of six isoprene units. Animals, plants and fungi all produce triterpenes, including squalene, the precursor to all steroids. Structures Triterpenes exist in a great variety of structures. Nearly 200 different skeletons have been identified. These skeletons may be broadly divided according to the number of rings present. In general pentacyclic structures (5 rings) tend to dominate. Squalene is biosynthesized through the head-to-head condensation of two farnesyl pyrophosphate units. This coupling converts a pair of C15 components into a C30 product. Squalene serves as precursor for the formation of many triterpenoids, including bacterial hopanoids and eukaryotic sterols. Triterpenoids By definition triterpenoids are triterpenes that possess heteroatoms, usually oxygen. The terms ''triterpene'' and ''triterpenoid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antitumor
Cancer can be treated by surgery, chemotherapy, radiation therapy, hormonal therapy, targeted therapy (including immunotherapy such as monoclonal antibody therapy) and synthetic lethality, most commonly as a series of separate treatments (e.g. chemotherapy before surgery). The choice of therapy depends upon the location and grade of the tumor and the stage of the disease, as well as the general state of the patient (performance status). Cancer genome sequencing helps in determining which cancer the patient exactly has for determining the best therapy for the cancer. A number of experimental cancer treatments are also under development. Under current estimates, two in five people will have cancer at some point in their lifetime. Complete removal of the cancer without damage to the rest of the body (that is, achieving cure with near-zero adverse effects) is the ideal, if rarely achieved, goal of treatment and is often the goal in practice. Sometimes this can be accomplished ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrophile
In chemistry, an electrophile is a chemical species that forms bonds with nucleophiles by accepting an electron pair. Because electrophiles accept electrons, they are Lewis acids. Most electrophiles are positively charged, have an atom that carries a partial positive charge, or have an atom that does not have an octet of electrons. Electrophiles mainly interact with nucleophiles through addition and substitution reactions. Frequently seen electrophiles in organic syntheses include cations such as H+ and NO+, polarized neutral molecules such as HCl, alkyl halides, acyl halides, and carbonyl compounds, polarizable neutral molecules such as Cl2 and Br2, oxidizing agents such as organic peracids, chemical species that do not satisfy the octet rule such as carbenes and radicals, and some Lewis acids such as BH3 and DIBAL. Organic chemistry Addition of halogens These occur between alkenes and electrophiles, often halogens as in halogen addition reactions. Common reactions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidative
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a decrease in the oxidation state. There are two classes of redox reactions: * ''Electron-transfer'' – Only one (usually) electron flows from the reducing agent to the oxidant. This type of redox reaction is often discussed in terms of redox couples and electrode potentials. * ''Atom transfer'' – An atom transfers from one substrate to another. For example, in the rusting of iron, the oxidation state of iron atoms increases as the iron converts to an oxide, and simultaneously the oxidation state of oxygen decreases as it accepts electrons released by the iron. Although oxidation reactions are commonly associated with the formation of oxides, other chemical species can serve the same function. In hydrogenation, C=C (and other) bonds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heme Oxygenase 1
''HMOX1'' (heme oxygenase 1 gene) is a human gene that encodes for the enzyme heme oxygenase 1 (). Heme oxygenase (abbreviated HMOX or HO) mediates the first step of heme catabolism, it cleaves heme to form biliverdin. The ''HMOX'' gene is located on the long (q) arm of chromosome 22 at position 12.3, from base pair 34,101,636 to base pair 34,114,748. Related conditions * Heme oxygenase-1 deficiency Heme oxygenase Heme oxygenase, an essential enzyme in heme catabolism, cleaves heme to form biliverdin, carbon monoxide, and ferrous iron. The biliverdin is subsequently converted to bilirubin by biliverdin reductase. Heme oxygenase activity is induced by its substrate heme and by various nonheme substances. Heme oxygenase occurs as 2 isozymes, an inducible heme oxygenase-1 and a constitutive heme oxygenase-2. HMOX1 and HMOX2 belong to the heme oxygenase family. See also * HMOX2 * Focal segmental glomerulosclerosis Focal segmental glomerulosclerosis (FSGS) is a histopatholo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NADH-quinone Oxidoreductase
NADH:ubiquinone reductase (non-electrogenic) (, '' NDH-2'', ''ubiquinone reductase'', ''coenzyme Q reductase'', ''dihydronicotinamide adenine dinucleotide-coenzyme Q reductase'', ''DPNH-coenzyme Q reductase'', ''DPNH-ubiquinone reductase'', ''NADH-coenzyme Q oxidoreductase'', ''NADH-coenzyme Q reductase'', ''NADH-CoQ oxidoreductase'', ''NADH-CoQ reductase'') is an enzyme with systematic name ''NADH:ubiquinone oxidoreductase''. This enzyme catalyses the following chemical reaction: :NADH + H+ + a quinone \rightleftharpoons NAD+ + a quinol The 3 substrates of this enzyme are NADH, H+, and a quinone (electron acceptor), whereas its two products are NAD+ and a quinol ( reduced acceptor). An important example of this reaction is: : NADH + H+ + ubiquinone \rightleftharpoons NAD+ + ubiquinol This enzyme is a flavoprotein (FAD). It belongs to the family of oxidoreductases, specifically those acting on NADH or NADPH with other acceptors. The systematic name of this enzyme class is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase 2 Response
Phase or phases may refer to: Science *State of matter, or phase, one of the distinct forms in which matter can exist *Phase (matter), a region of space throughout which all physical properties are essentially uniform *Phase space, a mathematical space in which each possible state of a physical system is represented by a point — this equilibrium point is also referred to as a "microscopic state" **Phase space formulation, a formulation of quantum mechanics in phase space *Phase (waves), the position of a point in time (an instant) on a waveform cycle **Instantaneous phase, generalization for both cyclic and non-cyclic phenomena * AC phase, the phase offset between alternating current electric power in multiple conducting wires **Single-phase electric power, distribution of AC electric power in a system where the voltages of the supply vary in unison **Three-phase electric power, a common method of AC electric power generation, transmission, and distribution *Phase problem, the l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrophages
Macrophages (abbreviated as M φ, MΦ or MP) ( el, large eaters, from Greek ''μακρός'' (') = large, ''φαγεῖν'' (') = to eat) are a type of white blood cell of the immune system that engulfs and digests pathogens, such as cancer cells, microbes, cellular debris, and foreign substances, which do not have proteins that are specific to healthy body cells on their surface. The process is called phagocytosis, which acts to defend the host against infection and injury. These large phagocytes are found in essentially all tissues, where they patrol for potential pathogens by amoeboid movement. They take various forms (with various names) throughout the body (e.g., histiocytes, Kupffer cells, alveolar macrophages, microglia, and others), but all are part of the mononuclear phagocyte system. Besides phagocytosis, they play a critical role in nonspecific defense ( innate immunity) and also help initiate specific defense mechanisms (adaptive immunity) by recruiting oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
COX-2
Prostaglandin-endoperoxide synthase 2 (prostaglandin G/H synthase and cyclooxygenase) (The HUGO official symbol is PTGS2; HGNC ID, HGNC:9605), also known as cyclooxygenase-2 or COX-2, is an enzyme that in humans is encoded by the ''PTGS2'' gene. In humans it is one of two cyclooxygenases. It is involved in the conversion of arachidonic acid to prostaglandin H2, an important precursor of prostacyclin, which is expressed in inflammation. Function PTGS2 (COX-2), converts arachidonic acid (AA) to prostaglandin endoperoxide H2. PTGSs are targets for NSAIDs and PTGS2 (COX-2) specific inhibitors called coxibs. PTGS-2 is a sequence homodimer. Each monomer of the enzyme has a peroxidase and a PTGS (COX) active site. The PTGS (COX) enzymes catalyze the conversion of arachidonic acid to prostaglandins in two steps. First, hydrogen is abstracted from carbon 13 of arachidonic acid, and then two molecules of oxygen are added by the PTGS2 (COX-2), giving PGG2. Second, PGG2 is reduced t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inducible Nitric Oxide Synthase
Nitric oxide synthases () (NOSs) are a family of enzymes catalyzing the production of nitric oxide (NO) from L-arginine. NO is an important cellular signaling molecule. It helps modulate vascular tone, insulin secretion, airway tone, and peristalsis, and is involved in angiogenesis and neural development. It may function as a retrograde neurotransmitter. Nitric oxide is mediated in mammals by the calcium-calmodulin controlled isoenzymes eNOS (endothelial NOS) and nNOS (neuronal NOS). The inducible isoform, iNOS, involved in immune response, binds calmodulin at physiologically relevant concentrations, and produces NO as an immune defense mechanism, as NO is a free radical with an unpaired electron. It is the proximate cause of septic shock and may function in autoimmune disease. NOS catalyzes the reaction: * 2 L-arginine + 3 NADPH + 3 H+ + 4 O2 \rightleftharpoons 2 citrulline +2 nitric oxide + 4 H2O + 3 NADP+ NOS isoforms catalyze other leak and side reactions, such as superoxi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IFN-γ
Interferon gamma (IFN-γ) is a dimerized soluble cytokine that is the only member of the type II class of interferons. The existence of this interferon, which early in its history was known as immune interferon, was described by E. F. Wheelock as a product of human leukocytes stimulated with phytohemagglutinin, and by others as a product of antigen-stimulated lymphocytes. It was also shown to be produced in human lymphocytes. or tuberculin-sensitized mouse peritoneal lymphocytes challenged with Mantoux test (PPD); the resulting supernatants were shown to inhibit growth of vesicular stomatitis virus. Those reports also contained the basic observation underlying the now widely employed IFN-γ release assay used to test for tuberculosis. In humans, the IFN-γ protein is encoded by the ''IFNG'' gene. Through cell signaling, IFN-γ plays a role in regulating the immune response of its target cell. A key signaling pathway that is activated by type II IFN is the JAK-STAT sign ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structural Analog
A structural analog (analogue in modern traditional English; Commonwealth English), also known as a chemical analog or simply an analog, is a compound having a structure similar to that of another compound, but differing from it in respect to a certain component. It can differ in one or more atoms, functional groups, or substructures, which are replaced with other atoms, groups, or substructures. A structural analog can be imagined to be formed, at least theoretically, from the other compound. Structural analogs are often isoelectronic. Despite a high chemical similarity, structural analogs are not necessarily functional analogs and can have very different physical, chemical, biochemical, or pharmacological properties. In drug discovery, either a large series of structural analogs of an initial lead compound are created and tested as part of a structure–activity relationship study or a database is screened for structural analogs of a lead compound. Chemical analogues of i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
