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Indazoles
Indazole, also called isoindazole, is a heterocyclic aromatic organic compound. This bicyclic compound consists of the fusion of benzene and pyrazole. Indazole is an Amphoterism, amphoteric molecule which can be protonated to an indazolium cation or deprotonated to an indazolate anion. The corresponding ''pKa'' values are 1.04 for the equilibrium between indazolium cation and indazole and 13.86 for the equilibrium between indazole and indazolate anion. Indazole derivatives display a broad variety of biological activities. Indazoles are rare in nature. The alkaloids nigellicine, nigeglanine, and nigellidine are indazoles. Nigellicine was isolated from the widely distributed plant ''Nigella sativa'' L. (black cumin). Nigeglanine was isolated from extracts of ''Nigella glandulifera''. The Davis–Beirut reaction can generate 2''H''-indazoles. Indazole, C7H6N2, was obtained by E. Fischer (''Ann.'' 1883, 221, p. 280) by heating ortho-hydrazine cinnamic acid, : Some derivatives ; i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indazoles
Indazole, also called isoindazole, is a heterocyclic aromatic organic compound. This bicyclic compound consists of the fusion of benzene and pyrazole. Indazole is an Amphoterism, amphoteric molecule which can be protonated to an indazolium cation or deprotonated to an indazolate anion. The corresponding ''pKa'' values are 1.04 for the equilibrium between indazolium cation and indazole and 13.86 for the equilibrium between indazole and indazolate anion. Indazole derivatives display a broad variety of biological activities. Indazoles are rare in nature. The alkaloids nigellicine, nigeglanine, and nigellidine are indazoles. Nigellicine was isolated from the widely distributed plant ''Nigella sativa'' L. (black cumin). Nigeglanine was isolated from extracts of ''Nigella glandulifera''. The Davis–Beirut reaction can generate 2''H''-indazoles. Indazole, C7H6N2, was obtained by E. Fischer (''Ann.'' 1883, 221, p. 280) by heating ortho-hydrazine cinnamic acid, : Some derivatives ; i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Davis–Beirut Reaction
The Davis–Beirut reaction is ''N,N''-bond forming heterocyclization that creates numerous types of 2''H''-indazoles and indazolones in both acidic and basic conditions The Davis–Beirut reaction is named after Mark Kurth and Makhluf Haddadin's respective universities; University of California, Davis and American University of Beirut, and is appealing because it uses inexpensive starting materials and does not require toxic metals. : Mechanism in base The current proposed mechanism for the Davis–Beirut reaction in base was first published in 2005 by Kurth, Olmstead, and Haddadin. The reaction occurs when a ''N''-substituted 2-nitrobenzylamine is heated in the presence of base, such as NaOH and KOH, and an alcohol and includes the formation of a carbanion The reaction begins with the base removing a hydrogen (1) adjacent to the secondary amine-group, creating a carbanion. The carbanion then extracts an oxygen from the nitro-group (2), which is then subsequently protonat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
7-Nitroindazole
7-Nitroindazole, or 7-NI, is a heterocyclic small molecule containing an indazole ring that has been nitrated at the 7 position. Nitroindazole acts as a selective inhibitor for neuronal nitric oxide synthase, a hemoprotein enzyme that, in neuronal tissue, converts arginine to citrulline and nitric oxide (NO). Nitric oxide can diffuse through the plasma membrane into neighbouring cells, allowing cell signalling, so nitroindazole indirectly inhibits this signalling process. Other inhibitors exist such as 3-bromo-7-nitroindazole, which is more potent but less specific, or NPA ( N-propyl-L-arginine), which acts on a different site. Pharmacology 7-Nitroindazole is under investigation as a possible protective agent against nerve damage caused by excitotoxicity or neurodegenerative diseases. It may act by reducing oxidative stress or by decreasing the amount of peroxynitrite formed in these tissues. These effects are related to the inhibition of type 1 nitric oxide synthase. Howeve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lonidamine
Lonidamine is a derivative of indazole-3-carboxylic acid, which for a long time, has been known to inhibit aerobic glycolysis in cancer cells. It seems to enhance aerobic glycolysis in normal cells, but suppress glycolysis in cancer cells. This is most likely through the inhibition of the mitochondrially bound hexokinase. Later studies in Ehrlich ascites tumor cells showed that lonidamine inhibits both respiration and glycolysis leading to a decrease in cellular ATP. Clinical trials of lonidamine in combination with other anticancer agents for a variety of cancers has begun. This is due to its proven ability to inhibit energy metabolism in cancer cells, and to enhance the activity of anticancer agents. Lonidamine has been used in the treatment of brain tumours in combination with radiotherapy and temozolomide. An in-vitro study showed that a combination of temozolomide and lonidamine at clinically achievable, low plasma concentrations, could inhibit tumour growth, and lonidamine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nigella Glandulifera
''Nigella'' is a genus of 18 species of annual plants in the family Ranunculaceae, native to Southern Europe, North Africa, South Asia, Southwest Asia and Middle East. Common names applied to members of this genus are nigella, devil-in-a-bush or love-in-a-mist. The species grow to tall, with finely divided leaves; the leaf segments are narrowly linear to threadlike. The flowers are white, yellow, pink, pale blue or pale purple, with five to ten petals. The fruit is a capsule composed of several united follicles, each containing numerous seeds; in some species (e.g. '' Nigella damascena''), the capsule is large and inflated. Uses Culinary The seeds of ''Nigella sativa'', known as ''kalonji'', black cumin, black caraway, black coriander, roman coriander, black onion seed, onion seed, charnushka, git (in historical Roman cuisine), or just nigella, are used as a spice and a condiment in South Asian cuisine, Ethiopian cuisine, Middle Eastern and Polish cuisines. Garden flowe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 superox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simple Aromatic Ring
Simple aromatic rings, also known as simple arenes or simple aromatics, are aromatic organic compounds that consist only of a conjugated planar ring system. Many simple aromatic rings have trivial names. They are usually found as substructures of more complex molecules (" substituted aromatics"). Typical simple aromatic compounds are benzene, indole, and pyridine. Simple aromatic rings can be heterocyclic if they contain non-carbon ring atoms, for example, oxygen, nitrogen, or sulfur. They can be monocyclic as in benzene, bicyclic as in naphthalene, or polycyclic as in anthracene. Simple monocyclic aromatic rings are usually five-membered rings like pyrrole or six-membered rings like pyridine. Fused/condensed aromatic rings consist of monocyclic rings that share their connecting bonds. Heterocyclic aromatic rings The nitrogen (N)-containing aromatic rings can be separated into basic aromatic rings that are easily protonated, and form aromatic cations and salts (e.g., pyridin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzimidazole
Benzimidazole is a heterocyclic aromatic organic compound. This bicyclic compound may be viewed as fused rings of the aromatic compounds benzene and imidazole. It is a colorless solid. Preparation Benzimidazole is produced by condensation of o-phenylenediamine with formic acid,. or the equivalent trimethyl orthoformate: :C6H4(NH2)2 + HC(OCH3)3 → C6H4N(NH)CH + 3 CH3OH 2-substituted derivatives are obtained when the condensation is conducted with aldehydes in place of formic acid, followed by oxidation.Robert A. Smiley "Phenylene- and Toluenediamines" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. Reactions Benzimidazole is a base: :C6H4N(NH)CH + H+ → [C6H4(NH)2CH]+ It can also be deprotonated with stronger bases: :C6H4N(NH)CH + LiH → Li [C6H4N2CH] + H2 The imine can be alkylated and also serves as a ligand in coordination chemistry. The most prominent benzimidazole complex features ''N''-ribosyl-dimethylbenzimidazole as found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atom
Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are extremely small, typically around 100 picometers across. They are so small that accurately predicting their behavior using classical physics, as if they were tennis balls for example, is not possible due to quantum effects. More than 99.94% of an atom's mass is in the nucleus. The protons have a positive electric charge, the electrons have a negative electric charge, and the neutrons have no electric charge. If the number of protons and electrons are equal, then the atom is electrically neutral. If an atom has more or fewer electrons than protons, then it has an overall negative or positive charge, respectively – such atoms are called ions. The electrons of an atom are a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seventh in total abundance in the Milky Way and the Solar System. At standard temperature and pressure, two atoms of the element bond to form N2, a colorless and odorless diatomic gas. N2 forms about 78% of Earth's atmosphere, making it the most abundant uncombined element. Nitrogen occurs in all organisms, primarily in amino acids (and thus proteins), in the nucleic acids ( DNA and RNA) and in the energy transfer molecule adenosine triphosphate. The human body contains about 3% nitrogen by mass, the fourth most abundant element in the body after oxygen, carbon, and hydrogen. The nitrogen cycle describes the movement of the element from the air, into the biosphere and organic compounds, then back into the atmosphere. Many indus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indole
Indole is an aromatic heterocyclic organic compound with the formula C8 H7 N. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered pyrrole ring. Indole is widely distributed in the natural environment and can be produced by a variety of bacteria. As an intercellular signal molecule, indole regulates various aspects of bacterial physiology, including spore formation, plasmid stability, resistance to drugs, biofilm formation, and virulence. The amino acid tryptophan is an indole derivative and the precursor of the neurotransmitter serotonin. General properties and occurrence Indole is a solid at room temperature. It occurs naturally in human feces and has an intense fecal odor. At very low concentrations, however, it has a flowery smell, and is a constituent of many perfumes. It also occurs in coal tar. The corresponding substituent is called indolyl. Indole undergoes electrophilic substitution, mainly at position 3 (see diagra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboxylic Acid
In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an R-group. The general formula of a carboxylic acid is or , with R referring to the alkyl, alkenyl, aryl, or other group. Carboxylic acids occur widely. Important examples include the amino acids and fatty acids. Deprotonation of a carboxylic acid gives a carboxylate anion. Examples and nomenclature Carboxylic acids are commonly identified by their trivial names. They at oftentimes have the suffix ''-ic acid''. IUPAC-recommended names also exist; in this system, carboxylic acids have an ''-oic acid'' suffix. For example, butyric acid (C3H7CO2H) is butanoic acid by IUPAC guidelines. For nomenclature of complex molecules containing a carboxylic acid, the carboxyl can be considered position one of the parent chain even if there are other substituents, such as 3-chloropropanoic acid. Alternately, it can be named as a "carboxy" or "carboxylic acid" substituent on another ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
