Umbelliferone is traditionally synthesized using the Pechmann condensation, from resorcinol and formylacetic acid (generated from malic acid in situ). A newer synthesis uses methyl propiolate and a palladium catalyst. ...

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Umbelliferone, Umbelliferone - Chemical synthesis, Umbelliferone - Ultraviolet fluorescence, Umbelliferone - Uses, Umbelliferone - Derivatives of umbelliferone

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The solution of proteins to be analyzed is first mixed with SDS, an anionic detergent which denatures secondary and non–disulfide–linked tertiary structures, and applies a negative charge to each protein in proportion to its mass. Without SDS, different proteins with similar molecular weights would migrate differently due to differences in folding, as differences in folding patterns would cause some proteins to better fit through the gel matrix than others. Adding SDS solves this problem, as it linearizes the proteins so that they may be ...

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SDS-PAGE, SDS-PAGE - Procedure

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Cimetidine was the prototypical histamine H2-receptor antagonist from which the later members of the class were developed. Cimetidine was the culmination of a project at Smith, Kline & French (SK&F; now GlaxoSmithKline) to develop a histamine receptor antagonist to suppress stomach acid secretion. At the time (1964) it was known that histamine was able to stimulate the secretion of stomach acid, but also that traditional antihistamines had no effect on acid production. In the process, the SK&F scient ...

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H₂-receptor antagonist, H₂-receptor antagonist - History and development, H₂-receptor antagonist - Pharmacology, H₂-receptor antagonist - Clinical use of H2-antagonists, H₂-receptor antagonist - Indications, H₂-receptor antagonist - Adverse drug reactions, H₂-receptor antagonist - Drug interactions, H₂-receptor antagonist - Examples

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Alkynes are generally prepared by dehydrohalogenation of vicinal alkyl dihalides or the reaction of metal acetylides with primary alkyl halides. In the Fritsch-Buttenberg-Wiechell rearrangement an alkyne is prepared starting from a vinyl bromide. Alkynes can be prepared from aldehydes using the Corey-Fuchs reaction or the Seyferth-Gilbert homologation. ...

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Alkyne, Alkyne - Structure, Alkyne - Chemical properties, Alkyne - Examples, Alkyne - Terminal and internal alkynes, Alkyne - Metal acetylides, Alkyne - Synthesis, Alkyne - Reactions

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The hydroxyl group generally makes the alcohol molecule polar. Those groups can form hydrogen bonds to one another and to other compounds. Two opposing solubility trends in alcohols are: the tendency of the polar OH to promote solubility in water, and of the carbon chain to resist it. Thus, methanol, ethanol, and propanol are miscible in water because the hydroxyl group wins out over the short carbon chain. Butanol, with a four-carbon chain, is moderately soluble because of a balance between the two trends. Alcohols of five or more carbons (Pentanol and higher) are effecti ...

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Alcohol, Alcohol - Structure, Alcohol - Primary secondary and tertiary alcohols, Alcohol - Methanol & ethanol, Alcohol - Uses, Alcohol - Sources, Alcohol - Nomenclature, Alcohol - Systematic names, Alcohol - Etymology, Alcohol - Physical and chemical properties, Alcohol - Toxicity, Alcohol - Preparation of alcohols, Alcohol - Laboratory, Alcohol - Industrial, Alcohol - Reactions of alcohols, Alcohol - Deprotonation, Alcohol - Nucleophilic substitution, Alcohol - Dehydration, Alcohol - Esterification, Alcohol - Oxidation

Read more here: » Alcohol: Encyclopedia II - Alcohol - Physical and chemical properties

Amine oxide - Pyrolytic elimination. Amine oxides, when heated to 150 to 200 ºC eliminate a hydroxylamine, resulting in an alkene. This pyrolytic syn-elimination reaction is known under the name Cope reaction. The mechanism is similar to that of the Hofmann elimination. Amine oxide - Reduction to amines. Amine oxides are readily converted to the parent amine by common reduction reagents including lithium aluminum hydride, sodium borohydride, catalytic reduction, zi ...

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Amine oxide, Amine oxide - Synthesis, Amine oxide - Reactions, Amine oxide - Pyrolytic elimination, Amine oxide - Reduction to amines, Amine oxide - Metabolites, Amine oxide - Prodrugs

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Acridine occurs naturally in coal tar. It is separated from coal tar by shaking out with dilute sulfuric acid, and then precipitating the sulfuric acid solution with potassium dichromate, the resulting acridine bichromate is decomposed in the final step by ammonia. Many synthetic processes are known for the production of acridine and its derivatives. A. Bernthsen condensed diphenylamine with carboxylic acids, in the presence of zinc chloride in the Bernthsen acridine synthesis. With Formic acid as the carboxylic acid the reaction yields acridine itself, and with the higher homologues the derivatives substituted at ...

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Acridine, Acridine - Sources, Acridine - Physical properties, Acridine - Chemical properties

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The thiol group is the sulfur analog of the hydroxyl group (-OH) found in alcohols. Since sulfur and oxygen belong to the same periodic table group, they share some similar chemical bonding properties. The chemistry of thiols is thus related to the chemistry of alcohols: thiols form thioethers, thioacetals and thioesters, which are analogous to ethers, acetals, and esters. Furthermore, a thiol group can react wi ...

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Thiol, Thiol - Chemistry, Thiol - Biological importance, Thiol - Nomenclature, Thiol - Etymology, Thiol - Examples of thiols

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Titrations are often recorded on titration curves, whose compositions are generally identical: the independent variable is the volume of the titrant, while the dependent variable is the pH of the solution (which changes depending on the composition of the two solutions). The equivalence point is a significant point on the graph (the point at which all of the starting solution, usually an acid, has been neutralized by the titrant, usually a base). It can be calculated precisely by finding the second derivative of the titration curve and compu ...

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Titration, Titration - Procedure, Titration - Titration curves, Titration - Biodiesel, Titration - Types

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Akt possesses a protein domain known as a PH domain, or Pleckstrin Homology domain, named after Pleckstrin, the protein in which it was first discovered. This domain binds to phosphoinositides with high affinity. In the case of the PH domain of Akt, it binds either phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P3 aka PIP3) or phosphatidylinositol 3,4-bisphosphate (PtdIns(3,4)P2 aka PI(3,4)P2). This is useful for control of cellular signaling because the di-phosphorylated phosphoinositide PI(4,5)P2 is only phosphorylated by the famil ...

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AKT, AKT - Regulation, AKT - Functions

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The modern era of CCC began with the development by Dr. Yoichiro Ito (of the National Institutes of Health) of the planetary centrifuge, and the many possible column geometries it can support. These clever devices make use of a little-known means of making non-rotating connections between the stator and the rotor of a centrifuge. (It is beyond the scope of this discussion to describe the method of accomplishing this. Any of the several books available on CCC discuss it thoroughly.) Functionally, the high-speed CCC consists of a helica ...

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Countercurrent chromatography, Countercurrent chromatography - Direct Countercurrent Chromatography DCCC, Countercurrent chromatography - Centrifugal Partition Chromatography CPC, Countercurrent chromatography - High-Speed Countercurrent Chromatography, Countercurrent chromatography - Modes of Operation

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Aldehydes are named by IUPAC nomenclature by changing the suffix -e of the parent alkane to -al. Aliphatic aldehydes are named as derivatives of their longest alkyl chain. Thus, HCHO is named as a derivative of methane, and CH3CH2CH2CHO is named as a derivative of butane. The suffix -al replaces the -e of the alkane name. Thus, HCHO is named methanal, more commonly known as formaldehyde, and CH3CH2 ...

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Aldehyde, Aldehyde - Structure, Aldehyde - α carbon & α hydrogen, Aldehyde - Carbonyl group, Aldehyde - Nomenclature, Aldehyde - Physical properties, Aldehyde - Chemistry, Aldehyde - Preparation, Aldehyde - Common reactions, Aldehyde - Nucleophilic addition, Aldehyde - Keto-enol tautomerism, Aldehyde - Oxidation & Reduction, Aldehyde - Examples of Aldehydes, Aldehyde - Etymology

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Carbonic acid has two acidic hydrogens and so two dissociation constants: H2CO3 ⇌ HCO3− + H+ Ka1 = 2.5×10−4 mol/L; pKa1 = 3.60. HCO3− ⇌ CO32− + H+ Ka2 = 5.61×10−11 mol/L; p ...

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Carbonic acid, Carbonic acid - Acidity of carbonic acid, Carbonic acid - Instability of carbonic acid, Carbonic acid - Carbonic acid and rain water

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Fatty acids can be bound or attached to other molecules, like triglycerides or phospholipids. When they are not attached to other molecules, they are known as "free" fatty acids. The uncombined fatty acids or free fatty acids may come from the breakdown of a triglyceride into its components (fatty acids and glycerol). Free fatty acids are an important source of fuel for many tissues since they can yield relatively large quantities of ATP. Many cell types can use either glucose or fatty acids for this purpose. Howe ...

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Fatty acid, Fatty acid - Types of fatty acids, Fatty acid - Saturated fatty acids, Fatty acid - Unsaturated fatty acids, Fatty acid - Free fatty acids, Fatty acid - pH, Fatty acid - Autoxidation and rancidity, Fatty acid - Sources

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Researchers have yet to fully characterize the solvation of hydronium ion in water, in part because many different meanings of solvation exist. A freezing point depression study determined that the mean hydration ion in cold water is approximately H3O+(H2O)6 (1): on average, each hydronium ion is solvated by 6 water molecules which are unable to solvate other solute molecules. Some hydration structures are quite large: the H3O+(H2O)20 magic ion num ...

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Hydronium, Hydronium - Nomenclature, Hydronium - Acids and Acidity, Hydronium - Solvation, Hydronium - Solid hydronium salts

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Boric acid is soluble in boiling water. When heated above 170°C it dehydrates, forming metaboric acid HBO2. Metaboric acid is a white, cubic crystalline solid and is only slightly soluble in water. It melts at about 236°C, and when heated above about 300°C further dehydrates, forming tetraboric acid or pyroboric acid, H4B4O7. Boric acid can refer to any of these compounds. ...

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Boric acid, Boric acid - Preparation, Boric acid - Properties, Boric acid - Uses, Boric acid - Reference

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Methanethiol is primarily used as an odorant to add warning properties to propane and natural gas used as fuel. Propane by itself is odorless, as are many sources of natural gas. Methanethiol is added for safety reasons so that gas leaks are readily noted by anyone present due to the odor. Methanethiol vaporizes readily and is odoriferous enough that only small quantities need be used. For propane, liquid methanethiol is mixed with liquid propane by the refinery. Methanethiol remains in solution in the desired concentration as the pro ...

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Methanethiol, Methanethiol - Uses, Methanethiol - St. Petersburg incident

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Terminal alkynes have a hydrogen atom bonded to at least one of the sp hybridized carbons (those involved in the triple bond. An example would be methylacetylene (1-propyne under IUPAC nomenclature). Internal alkynes have something other than hydrogen attached to the sp hybridized carbons, usually another carbon atom, but could be a heteroatom. A good example is 2-pentyne, in which there is a methyl group on one side ...

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Alkyne, Alkyne - Structure, Alkyne - Chemical properties, Alkyne - Examples, Alkyne - Terminal and internal alkynes, Alkyne - Metal acetylides, Alkyne - Synthesis, Alkyne - Reactions

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Indole chemistry began to develop with the study of the dye indigo. This was converted to isatin and then to oxindole. Then, in 1866, Adolf von Baeyer reduced oxindole to indole using zinc dust. In 1869, he proposed the formula for indole (left) that is accepted today.[1] Certain indole derivatives were important dyestuffs until the end of the 19th century. In the 1930s, interest in indole intensified when it became known that the indole nucleus is present in many important alkaloids, as well is in tryptophan and auxins, and it remains ...

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Indole, Indole - History, Indole - Synthesis of indoles, Indole - Leimgruber-Batcho indole synthesis, Indole - Fischer indole synthesis, Indole - Other indole forming reactions, Indole - Chemical reactions of indole, Indole - Nitrogen basicity, Indole - Electrophilic substitution, Indole - Nitrogen-H acidity and organometallic indole anion complexes, Indole - Carbon acidity and C-2 lithiation, Indole - Oxidation of indole, Indole - Cycloadditions of indole, Indole - Applications, Indole - General references

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H₂-receptor antagonist - Indications. H2-antagonists are clinically used in the treatment of acid-related gastrointestinal conditions. Specifically, these indications may include: (Rossi, 2005) peptic ulcer disease (PUD) gastroesophageal reflux disease (GERD) dyspepsia stress ulcer prophylaxis (raniditine) People that suffer from heartburn (GERD) infrequently may take either antacids or H2-receptor antagonists for treatment. H2See also:

H₂-receptor antagonist, H₂-receptor antagonist - History and development, H₂-receptor antagonist - Pharmacology, H₂-receptor antagonist - Clinical use of H2-antagonists, H₂-receptor antagonist - Indications, H₂-receptor antagonist - Adverse drug reactions, H₂-receptor antagonist - Drug interactions, H₂-receptor antagonist - Examples

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Alcohol - Deprotonation. Alcohols can behave as weak acids, undergoing deprotonation. The deprotonation reaction to produce an alkoxide salt is either performed with a strong base such as sodium hydride or n-butyllithium, or with sodium or potassium metal. 2 R-OH + 2 NaH → 2 R-O-Na+ + H2↑ 2 R-OH + 2Na → 2R-O−Na+ e.g. 2 CH3CH2-OH + 2 Na → 2 CH3-CH ...

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Alcohol, Alcohol - Structure, Alcohol - Primary secondary and tertiary alcohols, Alcohol - Methanol & ethanol, Alcohol - Uses, Alcohol - Sources, Alcohol - Nomenclature, Alcohol - Systematic names, Alcohol - Etymology, Alcohol - Physical and chemical properties, Alcohol - Toxicity, Alcohol - Preparation of alcohols, Alcohol - Laboratory, Alcohol - Industrial, Alcohol - Reactions of alcohols, Alcohol - Deprotonation, Alcohol - Nucleophilic substitution, Alcohol - Dehydration, Alcohol - Esterification, Alcohol - Oxidation

Read more here: » Alcohol: Encyclopedia II - Alcohol - Reactions of alcohols

Slovakia at the 2004 Summer Olympics - Athletics. Women's 800 metres: Lucia Klocová - Round 1: 2:02.17, Semifinal: 2:00.79 Men's Marathon: Marcel Matanin - 2:50:26 (81st place) Men's 20 km Walk: Matej Tóth - 1:28:49 (32nd place) Women's 20 km Walk: Zuzana Malíková - 1:33:17 (22nd place) Men's 50 km Walk: Peter Korčok - 3:54:22 (14th place) Miloš Bátovský - 3: ...

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Slovakia at the 2004 Summer Olympics, Slovakia at the 2004 Summer Olympics - Medals, Slovakia at the 2004 Summer Olympics - Gold, Slovakia at the 2004 Summer Olympics - Silver, Slovakia at the 2004 Summer Olympics - Bronze, Slovakia at the 2004 Summer Olympics - Results by event, Slovakia at the 2004 Summer Olympics - Athletics, Slovakia at the 2004 Summer Olympics - Canoeing, Slovakia at the 2004 Summer Olympics - Cycling, Slovakia at the 2004 Summer Olympics - Gymnastics, Slovakia at the 2004 Summer Olympics - Judo, Slovakia at the 2004 Summer Olympics - Rowing, Slovakia at the 2004 Summer Olympics - Shooting, Slovakia at the 2004 Summer Olympics - Swimming, Slovakia at the 2004 Summer Olympics - Synchronised Swimming, Slovakia at the 2004 Summer Olympics - Tennis, Slovakia at the 2004 Summer Olympics - Weightlifting, Slovakia at the 2004 Summer Olympics - Wrestling, Slovakia at the 2004 Summer Olympics - Officials, Slovakia at the 2004 Summer Olympics - External link

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