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4,5-Dihydroxy-2,3-pentanedione
4,5-Dihydroxy-2,3-pentanedione (DPD) is an organic compound that occurs naturally but exists as several related structures. The idealized formula for this species is CH3C(O)C(O)CH(OH)CH2OH, but it is known to exist as several other forms resulting from cyclization. It is not stable at room temperature as a pure material, which has further complicated its analysis. The (''S'')-stereoisomer occurs naturally. It is typically hydrated, i.e., one keto group has added water to give the geminal diol. DPD is produced by degradation of ''S''-adenosylhomocysteine by the action of the enzyme ''S''-ribosylhomocysteinase. The compound probably does not exist as depicted above, but as an equilibrium mixture of three hydrates. DPD is a precursor to borate diester, which is known as autoinducer-2 (AI-2). AI-2 is a signaling molecules found in quorum sensing. It is produced and recognized by many Gram-negative and Gram-positive bacteria. AI-2 is synthesized by the reaction of DPD with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autoinducer-2
Autoinducer-2 (AI-2), a furanosyl borate diester or tetrahydroxy furan (species dependent), is a member of a family of signaling molecules used in quorum sensing. AI-2 is one of only a few known biomolecules incorporating boron. First identified in the marine bacterium ''Vibrio harveyi'', AI-2 is produced and recognized by many Gram-negative and Gram-positive bacteria. AI-2 arises by the reaction of 4,5-Dihydroxy-2,3-pentanedione, which is produced enzymatically with boric acid, and is recognized by the two-component sensor kinase LuxPQ in Vibrionaceae. AI-2 is actively transported by the Lsr ABC-type transporter into the cell in Enterobacteriaceae and few other bacterial taxa ('' Pasteurella'', '' Photorhabdus'', ''Haemophilus'', ''Bacillus ''Bacillus'' (Latin "stick") is a genus of Gram-positive, rod-shaped bacteria, a member of the phylum '' Bacillota'', with 266 named species. The term is also used to describe the shape (rod) of other so-shaped bacteria; and the plura ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon- hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, hydrogen cyanide), are not classified as organic compounds and are considered inorganic. Other than those just named, little consensus exists among chemists on precisely which carbon-containing compounds are excluded, making any rigorous definition of an organic compound elusive. Although organic compounds make up only a small percentage of Earth's crust, they are of central importance because all known life is based on organic compounds. Livin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Cell
''Molecular Cell'' is a peer-reviewed scientific journal that covers research on cell biology at the molecular level, with an emphasis on new mechanistic insights. It was established in 1997 and is published two times per month. Its 2021 impact factor is 19.328. ''Molecular Cell'' is a Cell Press journal (an imprint of Elsevier) and is a companion to ''Cell Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery w ...''. Launched in December 1997, ''Molecular Cell'' publishes a relatively small number of papers, up to 15 articles per issue. Coverage includes structure to human diseases, concentrating on molecular analyses. Topics include gene expression, RNA processing, replication, recombination and repair, structure, chaperones, receptors, signal transduction, cell cycle, metabolism, and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbohydrate Chemistry
Carbohydrate chemistry is a subdiscipline of chemistry primarily concerned with the detection, synthesis, structure, and function of carbohydrates. Due to the general structure of carbohydrates, their synthesis is often preoccupied with the selective formation of glycosidic linkages and the selective reaction of hydroxyl groups; as a result, it relies heavily on the use of protecting groups. Monosaccharides Individual saccharide residues are termed monosaccharides. Carbohydrate synthesis Carbohydrate synthesis is a sub-field of organic chemistry concerned specifically with the generation of natural and unnatural carbohydrate structures. This can include the synthesis of monosaccharide residues or structures containing more than one monosaccharide, known as oligosaccharides. Glycosidic bond formation * Chemical glycosylation * Fischer glycosidation * Glycosyl halide * Koenigs-Knorr reaction Protecting groups * Carbohydrate acetalisation * Trimethylsilyl * Benzyl Ether * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vicinal Diols axis.
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Vicinal may refer to: * Vicinal (chemistry), stands for any two functional groups bonded to two adjacent atoms. * Vicinal (logology), a word where all letters have alphabetic neighbors. * Vicinal tramway or ''Buurtspoor'', a system of narrow gauge tramways or local railways in Belgium. * In materials science, a "vicinal substrate" is a thin-film substrate whose surface normal deviates slightly from a major crystallographic Crystallography is the experimental science of determining the arrangement of atoms in crystalline solids. Crystallography is a fundamental subject in the fields of materials science and solid-state physics (condensed matter physics). The word ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diketones
In organic chemistry, a dicarbonyl is a molecule containing two carbonyl () groups. Although this term could refer to any organic compound containing two carbonyl groups, it is used more specifically to describe molecules in which both carbonyls are in close enough proximity that their reactivity is changed, such as 1,2-, 1,3-, and 1,4-dicarbonyls. Their properties often differ from those of monocarbonyls, and so they are usually considered functional groups of their own. These compounds can have symmetrical or unsymmetrical substituents on each carbonyl, and may also be functionally symmetrical (dialdehydes, diketones, diesters, ''etc.'') or unsymmetrical (keto-esters, keto-acids, ''etc.''). 1,2-Dicarbonyls 1,2-Dialdehyde The only 1,2-dialdehyde is glyoxal, . Like many alkyldialdehydes, glyoxal is encountered almost exclusively as its hydrate and oligomers thereof. These derivatives often behave equivalently to the aldehydes since hydration is reversible. Glyoxal condenses ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vibrionaceae
The Vibrionaceae are a family of Pseudomonadota given their own order, Vibrionales. Inhabitants of fresh or salt water, several species are pathogenic, including the type species ''Vibrio cholerae'', which is the agent responsible for cholera. Most bioluminescent bacteria belong to this family, and are typically found as symbionts of deep-sea animals. Vibrionaceae are Gram-negative organisms and facultative anaerobes, capable of fermentation. They contain oxidase and have one or more flagella, which are generally polar. Originally, these characteristics defined the family, which was divided into four genera. Two of these, ''Vibrio'' and '' Photobacterium'', correspond to the modern group, although several new genera have been defined. Genetic studies have shown the other two original members—''Aeromonas'' and '' Plesiomonas''—belong to separate families. The family Vibrionaceae currently comprises eight validly published genera: ''Aliivibrio'', ''Catenococcus'', '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boric Acid
Boric acid, more specifically orthoboric acid, is a compound of boron, oxygen, and hydrogen with formula . It may also be called hydrogen borate or boracic acid. It is usually encountered as colorless crystals or a white powder, that dissolves in water, and occurs in nature as the mineral sassolite. It is a weak acid that yields various borate anions and salts, and can react with alcohols to form borate esters. Boric acid is often used as an antiseptic, insecticide, flame retardant, neutron absorber, or precursor to other boron compounds. The term "boric acid" is also used generically for any oxoacid of boron, such as metaboric acid and tetraboric acid . History Orthoboric acid was first prepared by Wilhelm Homberg (1652–1715) from borax, by the action of mineral acids, and was given the name ("sedative salt of Homberg"). However boric acid and borates have been used since the time of the ancient Greeks for cleaning, preserving food, and other activities. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annual Review Of Microbiology
The ''Annual Review of Microbiology'' is a peer-reviewed academic journal that publishes review articles about microbiology. It was first published in 1947 as the third journal title released by Annual Reviews. It covers significant developments in the field of microbiology, including the study of bacteria, archaea, viruses, and unicellular eukaryotes. As of 2020, it has had four editors, with Charles E. Clifton and L. Nicholas Ornston serving more than twenty years each. The current editor is Susan Gottesman. History The ''Annual Review of Microbiology'' was first published in 1947, the third journal title released by the publishing company Annual Reviews, following titles in biochemistry and physiology. Its first editor was Charles E. Clifton. From 1956 to 1958, Pierre Grabar provided a summary of the microbiologic literature appearing in the Russian language through a partnership with the National Science Foundation. This was no longer necessary as abstracts became increa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-positive Bacteria
In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bacteria take up the crystal violet stain used in the test, and then appear to be purple-coloured when seen through an optical microscope. This is because the thick peptidoglycan layer in the bacterial cell wall retains the stain after it is washed away from the rest of the sample, in the decolorization stage of the test. Conversely, gram-negative bacteria cannot retain the violet stain after the decolorization step; alcohol used in this stage degrades the outer membrane of gram-negative cells, making the cell wall more porous and incapable of retaining the crystal violet stain. Their peptidoglycan layer is much thinner and sandwiched between an inner cell membrane and a bacterial outer membrane, causing them to take up the counterstain ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
