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Oxathiazolones
The oxathiazolones are a family of heterocyclic compounds in which the parent derivative has the molecular formula C2HNO2S and for which multiple isomers are known. The two known isomers with the highest profile in the literature are 1,3,4-oxathiazol-2-one and 1,4,2-oxathiazol-5-one. 1,3,4-Oxathiazol-2-one Molecular and electronic structure 1,3,4-Oxathiaol-2-one derivatives are planar heterocycles that prefer co-planarity with aromatic substituents. It has been proposed that the π system of the ring consists of CNS and CO2 "π islands" that prefer coplanarity to enhance inter-ring π conjugation. Synthesis The traditional route for 1,3,4-oxathiazol-2-one synthesis is via 1,3 dipolar cycloaddition, where chlorocarbonylsulfenyl chloride and amide are heated together in an appropriate solvent. Appropriate solvents must dissolve the amide. Typically toluene or chloroform is used. A wide variety of amides have been used is the synthesis of 1,3,4-oxathiazol-2-one yielding vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrile
In organic chemistry, a nitrile is any organic compound that has a functional group. The name of the compound is composed of a base, which includes the carbon of the , suffixed with "nitrile", so for example is called " propionitrile" (or propanenitrile). The prefix '' cyano-'' is used interchangeably with the term ''nitrile'' in industrial literature. Nitriles are found in many useful compounds, including methyl cyanoacrylate, used in super glue, and nitrile rubber, a nitrile-containing polymer used in latex-free laboratory and medical gloves. Nitrile rubber is also widely used as automotive and other seals since it is resistant to fuels and oils. Organic compounds containing multiple nitrile groups are known as cyanocarbons. Inorganic compounds containing the group are not called nitriles, but cyanides instead. Though both nitriles and cyanides can be derived from cyanide salts, most nitriles are not nearly as toxic. Structure and basic properties The N−C−C geom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxathiazolone Isomers
The oxathiazolones are a family of heterocyclic compounds in which the parent derivative has the molecular formula C2HNO2S and for which multiple isomers are known. The two known isomers with the highest profile in the literature are 1,3,4-oxathiazol-2-one and 1,4,2-oxathiazol-5-one. 1,3,4-Oxathiazol-2-one Molecular and electronic structure 1,3,4-Oxathiaol-2-one derivatives are planar heterocycles that prefer co-planarity with aromatic substituents. It has been proposed that the π system of the ring consists of CNS and CO2 "π islands" that prefer coplanarity to enhance inter-ring π conjugation. Synthesis The traditional route for 1,3,4-oxathiazol-2-one synthesis is via 1,3 dipolar cycloaddition, where chlorocarbonylsulfenyl chloride and amide are heated together in an appropriate solvent. Appropriate solvents must dissolve the amide. Typically toluene or chloroform is used. A wide variety of amides have been used is the synthesis of 1,3,4-oxathiazol-2-one yielding vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycobacterium Tuberculosis
''Mycobacterium tuberculosis'' (M. tb), also known as Koch's bacillus, is a species of pathogenic bacteria in the family Mycobacteriaceae and the causative agent of tuberculosis. First discovered in 1882 by Robert Koch, ''M. tuberculosis'' has an unusual, waxy coating on its cell surface primarily due to the presence of mycolic acid. This coating makes the cells impervious to Gram staining, and as a result, ''M. tuberculosis'' can appear weakly Gram-positive. Acid-fastness, Acid-fast stains such as Ziehl–Neelsen stain, Ziehl–Neelsen, or Fluorescence, fluorescent stains such as Auramine O, auramine are used instead to identify ''M. tuberculosis'' with a microscope. The physiology of ''M. tuberculosis'' is highly aerobic organism, aerobic and requires high levels of oxygen. Primarily a pathogen of the mammalian respiratory system, it infects the lungs. The most frequently used diagnostic methods for tuberculosis are the Mantoux test, tuberculin skin test, Acid-Fast Stain, aci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkene
In organic chemistry, an alkene, or olefin, is a hydrocarbon containing a carbon–carbon double bond. The double bond may be internal or at the terminal position. Terminal alkenes are also known as Alpha-olefin, α-olefins. The International Union of Pure and Applied Chemistry (IUPAC) Preferred IUPAC name, recommends using the name "alkene" only for Open-chain compound, acyclic hydrocarbons with just one double bond; alkadiene, alkatriene, etc., or polyene for acyclic hydrocarbons with two or more double bonds; cycloalkene, cycloalkadiene, etc. for Cyclic compound, cyclic ones; and "olefin" for the general class – cyclic or acyclic, with one or more double bonds. Acyclic alkenes, with only one double bond and no other functional groups (also known as mono-enes) form a homologous series of hydrocarbons with the general formula with ''n'' being a >1 natural number (which is two hydrogens less than the corresponding alkane). When ''n'' is four or more, isomers are possible, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphaalkene
Phosphaalkenes (IUPAC name: alkylidenephosphanes) are organophosphorus compounds with double bonds between carbon and phosphorus(III) with the formula R2C=PR. In the compound phosphorine one carbon atom in benzene is replaced by phosphorus. The reactivity of phosphaalkenes is often compared to that of alkenes and not to that of imines because the HOMO of phosphaalkenes is not the phosphorus lone pair (as in imines the amine lone pair) but the double bond. Therefore like alkenes, phosphaalkenes engage in Wittig reactions, Peterson reactions, Cope rearrangements and Diels-Alder reactions. The first phosphaalkene discovered was a phosphabenzene, by Mërkl in 1969. The first localized phosphaalkene was reported in 1976 by Gerd Becker as a keto-enol tautomerism akin a Brook rearrangement: :: In the same year Harold Kroto established spectroscopically that thermolysis of Me2PH generates CH2=PMe. A general method for the synthesis of phosphaalkenes is by 1,2-elimination of suita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biologically Significant 1,3,40oxathiazol-2-one
Biology is the scientific study of life and living organisms. It is a broad natural science that encompasses a wide range of fields and unifying principles that explain the structure, function, growth, origin, evolution, and distribution of life. Central to biology are five fundamental themes: the cell as the basic unit of life, genes and heredity as the basis of inheritance, evolution as the driver of biological diversity, energy transformation for sustaining life processes, and the maintenance of internal stability (homeostasis). Biology examines life across multiple levels of organization, from molecules and cells to organisms, populations, and ecosystems. Subdisciplines include molecular biology, physiology, ecology, evolutionary biology, developmental biology, and systematics, among others. Each of these fields applies a range of methods to investigate biological phenomena, including observation, experimentation, and mathematical modeling. Modern biology is grounded in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteasome
Proteasomes are essential protein complexes responsible for the degradation of proteins by proteolysis, a chemical reaction that breaks peptide bonds. Enzymes that help such reactions are called proteases. Proteasomes are found inside all eukaryotes and archaea, and in some bacteria. In eukaryotes, proteasomes are located both in the nucleus and in the cytoplasm. The proteasomal degradation pathway is essential for many cellular processes, including the cell cycle, the regulation of gene expression, and responses to oxidative stress. The importance of proteolytic degradation inside cells and the role of ubiquitin in proteolytic pathways was acknowledged in the award of the 2004 Nobel Prize in Chemistry to Aaron Ciechanover, Avram Hershko and Irwin Rose. The core 20S proteasome (blue in the adjacent figure) is a cylindrical, compartmental protein complex of four stacked rings forming a central pore. Each ring is composed of seven individual proteins. The inner two rings a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterocyclic Compounds
A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic organic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and applications of organic heterocycles. Examples of heterocyclic compounds include all of the nucleic acids, the majority of drugs, most biomass (cellulose and related materials), and many natural and synthetic dyes. More than half of known compounds are heterocycles. 59% of US FDA-approved drugs contain nitrogen heterocycles. Classification The study of organic heterocyclic chemistry focuses especially on organic unsaturated derivatives, and the preponderance of work and applications involves unstrained organic 5- and 6-membered rings. Included are pyridine, thiophene, pyrrole, and furan. Another large class of organic heterocycles refers to those fused to benzene rings. For example, the fused benzene derivatives of pyridin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuberculosis Management
Management of tuberculosis refers to techniques and procedures utilized for treating tuberculosis (TB), or simply a treatment plan for TB. The medical standard for active TB is a short course treatment involving a combination of isoniazid, rifampicin (also known as Rifampin), pyrazinamide, and ethambutol for the first two months. During this initial period, Isoniazid is taken alongside pyridoxal phosphate to obviate peripheral neuropathy. Isoniazid is then taken concurrently with rifampicin for the remaining four months of treatment (6-8 months for miliary tuberculosis). A patient is expected to be free from all living TB bacteria after six months of therapy in Pulmonary TB or 8-10 months in Miliary TB. Latent tuberculosis or latent tuberculosis infection (LTBI) is treated with three to nine months of isoniazid alone. This long-term treatment often risks the development of hepatotoxicity. A combination of isoniazid plus rifampicin for a period of three to four months is shown to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cancer
Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible Signs and symptoms of cancer, signs and symptoms include a lump, abnormal bleeding, prolonged cough, unexplained weight loss, and a change in defecation, bowel movements. While these symptoms may indicate cancer, they can also have other causes. List of cancer types, Over 100 types of cancers affect humans. Tobacco use is the cause of about 22% of cancer deaths. Another 10% are due to obesity, poor Diet (nutrition), diet, sedentary lifestyle, lack of physical activity or Alcohol abuse, excessive alcohol consumption. Other factors include certain infections, exposure to ionizing radiation, and environmental pollutants. infectious causes of cancer, Infection with specific viruses, bacteria and parasites is an environmental factor cau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
