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Apparicine
Apparicine is a monoterpenoid indole alkaloid. It is named after Apparicio Duarte, a Brazilian botanist who studied the ''Aspidosperma'' species from which apparicine was first isolated. It was the first member of the vallesamine group of alkaloids to be isolated and have its structure established, which was first published in 1965. It has also been known by the synonyms gomezine, pericalline, and tabernoschizine. Biochemistry The alkaloid has been isolated from seven species of ''Aspidosperma''. It is the principal alkaloid found in the callus of ''Tabernaemontana elegans'', and has also been identified in other ''Tabernaemontana'' species, including '' T. africana'', '' T. divaricata'', '' T. orientalis'', and '' T. pachysiphon''. In studies of ''T. pachysiphon'', it was found that alkaloid content including that of apparicine was greatest in young leaves and leaves receiving greater shade, and varied with leaf age, plant age, and provenance. Research on '' Aspidosperma pyri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoterpenoid
Monoterpenes are a class of terpenes that consist of two isoprene units and have the molecular formula C10H16. Monoterpenes may be linear (acyclic) or contain rings (monocyclic and bicyclic). Modified terpenes, such as those containing oxygen functionality or missing a methyl group, are called monoterpenoids. Monoterpenes and monoterpenoids are diverse. They have relevance to the pharmaceutical, cosmetic, agricultural, and food industries. Biosynthesis Monoterpenes are derived biosynthetically from units of isopentenyl pyrophosphate, which is formed from acetyl-CoA via the intermediacy of mevalonic acid in the HMG-CoA reductase pathway. An alternative, unrelated biosynthesis pathway of IPP is known in some bacterial groups and the plastids of plants, the so-called MEP-(2-methyl-D-erythritol-4-phosphate) pathway, which is initiated from Pentose, C5 sugars. In both pathways, IPP is isomerized to DMAPP by the enzyme isopentenyl pyrophosphate isomerase. Geranyl pyrophosphate is the pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tryptamine
Tryptamine is an indolamine metabolite of the essential amino acid, tryptophan. The chemical structure is defined by an indole ─ a fused benzene and pyrrole ring, and a 2-aminoethyl group at the second carbon (third aromatic atom, with the first one being the heterocyclic nitrogen). The structure of tryptamine is a shared feature of certain aminergic neuromodulators including melatonin, serotonin, bufotenin and psychedelic derivatives such as dimethyltryptamine (DMT), psilocybin, psilocin and others. Tryptamine has been shown to activate trace amine-associated receptors expressed in the mammalian brain, and regulates the activity of dopaminergic, serotonergic and glutamatergic systems. In the human gut, symbiotic bacteria convert dietary tryptophan to tryptamine, which activates 5-HT4 receptors and regulates gastrointestinal motility. Multiple tryptamine-derived drugs have been developed to treat migraines, while trace amine-associated receptors are being explored as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permanganate
A permanganate () is a chemical compound containing the manganate(VII) ion, , the conjugate base of permanganic acid. Because the manganese atom is in the +7 oxidation state, the permanganate(VII) ion is a strong oxidizing agent. The ion is a transition metal oxo complex with tetrahedral geometry. Permanganate solutions are purple in color and are stable in neutral or slightly alkaline media. The exact chemical reaction is dependent upon the organic contaminants present and the oxidant utilized. For example, trichloroethane (C2H3Cl3) is oxidized by permanganate ions to form carbon dioxide (CO2), manganese dioxide (MnO2), hydrogen ions (H+), and chloride ions (Cl−). :8 + 3 → 6 + 8 + + 4 + 9 In an acidic solution, permanganate(VII) is reduced to the pale pink +2 oxidation state of the manganese(II) (Mn2+) ion. :8 + + 5 e− → Mn2+ + 4 H2O In a strongly basic solution, permanganate(VII) is reduced to the green +6 oxidation state of the manganate ion, . : ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidation
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 ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dehydrogenation
In chemistry, dehydrogenation is a chemical reaction that involves the removal of hydrogen, usually from an organic molecule. It is the reverse of hydrogenation. Dehydrogenation is important, both as a useful reaction and a serious problem. At its simplest, it is useful way of converting alkanes, which are relatively inert and thus low-valued, to olefins, which are reactive and thus more valuable. Alkenes are precursors to aldehydes (), alcohols (), polymers, and aromatics. As a problematic reaction, the fouling and inactivation of many catalysts arises via coking, which is the dehydrogenative polymerization of organic substrates. Enzymes that catalyze dehydrogenation are called dehydrogenases. Heterogeneous catalytic routes Styrene Dehydrogenation processes are used extensively to produce aromatics in the petrochemical industry. Such processes are highly endothermic and require temperatures of 500 °C and above. Dehydrogenation also converts saturated fats to unsatura ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skeletal Formula
The skeletal formula, or line-angle formula or shorthand formula, of an organic compound is a type of molecular structural formula that serves as a shorthand representation of a molecule's bonding and some details of its molecular geometry. A skeletal formula shows the skeletal structure or skeleton of a molecule, which is composed of the skeletal atoms that make up the molecule. It is represented in two dimensions, as on a piece of paper. It employs certain conventions to represent carbon and hydrogen atoms, which are the most common in organic chemistry. An early form of this representation was first developed by organic chemist August Kekulé, while the modern form is closely related to and influenced by the Lewis structure of molecules and their valence electrons. Hence they are sometimes termed Kekulé structures or Lewis–Kekulé structures. Skeletal formulae have become ubiquitous in organic chemistry, partly because they are relatively quick and simple to draw, and ... [...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] |
Methylene Bridge
In organic chemistry, a methylene bridge, methylene spacer, or methanediyl group is any part of a molecule with formula ; namely, a carbon atom bound to two hydrogen atoms and connected by single bonds to two other distinct atoms in the rest of the molecule. It is the repeating unit in the skeleton of the unbranched alkanes. A methylene bridge can also act as a bidentate ligand joining two metals in a coordination compound, such as titanium and aluminum in Tebbe's reagent.W. A. Herrmann (1982), "The methylene bridge". In ''Advances in Organometallic Chemistry'', volume 20, pages 195-197. A methylene bridge is often called a methylene group or simply methylene, as in "methylene chloride" (dichloromethane ). As a bridge in other compounds, for example in cyclic compounds, it is given the name methano. However, the term methylene group (or "methylidene") properly applies to the group when it is connected to the rest of the molecule by a double bond (), giving it chemical proper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromophore
A chromophore is the part of a molecule responsible for its color. The color that is seen by our eyes is the one not absorbed by the reflecting object within a certain wavelength spectrum of visible light. The chromophore is a region in the molecule where the energy difference between two separate molecular orbitals falls within the range of the visible spectrum. Visible light that hits the chromophore can thus be absorbed by exciting an electron from its ground state into an excited state. In biological molecules that serve to capture or detect light energy, the chromophore is the moiety that causes a conformational change in the molecule when hit by light. Conjugated pi-bond system chromophores Just like how two adjacent p-orbitals in a molecule will form a pi-bond, three or more adjacent p-orbitals in a molecule can form a conjugated pi-system. In a conjugated pi-system, electrons are able to capture certain photons as the electrons resonate along a certain distance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultraviolet–visible Spectroscopy
UV spectroscopy or UV–visible spectrophotometry (UV–Vis or UV/Vis) refers to absorption spectroscopy or reflectance spectroscopy in part of the ultraviolet and the full, adjacent visible regions of the electromagnetic spectrum. Being relatively inexpensive and easily implemented, this methodology is widely used in diverse applied and fundamental applications. The only requirement is that the sample absorb in the UV-Vis region, i.e. be a chromophore. Absorption spectroscopy is complementary to fluorescence spectroscopy. Parameters of interest, besides the wavelength of measurement, are absorbance (A) or transmittance (%T) or reflectance (%R), and its change with time. Optical transitions Most molecules and ions absorb energy in the ultraviolet or visible range, i.e., they are chromophores. The absorbed photon excites an electron in the chromophore to higher energy molecular orbitals, giving rise to an excited state. For organic chromophores, four possible types of transitions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isotopes Of Hydrogen
Hydrogen (1H) has three naturally occurring isotopes, sometimes denoted , , and . and are stable, while has a half-life of years. Heavier isotopes also exist, all of which are synthetic and have a half-life of less than one zeptosecond (10−21 s). Of these, is the least stable, while is the most. Hydrogen is the only element whose isotopes have different names that remain in common use today: the (or hydrogen-2) isotope is deuterium and the (or hydrogen-3) isotope is tritium. The symbols D and T are sometimes used for deuterium and tritium. The IUPAC accepts the D and T symbols, but recommends using standard isotopic symbols ( and ) instead to avoid confusion in the alphabetic sorting of chemical formulas. The isotope , with no neutrons, is sometimes called protium. (During the early study of radioactivity, some other heavy radioactive isotopes were given names, but such names are rarely used today.) List of isotopes , - , , 1 , 0 , , colspan=3 align=ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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