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Luteolin-7-O-β-D-glucoside
Cynaroside (also known as luteoloside) is a flavone, a flavonoid-like chemical compound. It is a 7-O-glucoside of luteolin. Natural occurrences It can be found in '' Ferula varia'' and '' F. foetida'' in '' Campanula persicifolia'' and '' C. rotundifolia'', in the bamboo ''Phyllostachys nigra'', and in '' Teucrium gnaphalodes''. ; In food It can be found in dandelion (the highest concentration in the flowers, but also in the roots) and in ''Cynara scolymus'' (artichoke). Metabolism Flavone 7-O-beta-glucosyltransferase adds a glucose to luteolin Luteolin is a flavone, a type of flavonoid, with a yellow crystalline appearance. Luteolin is the main yellow dye from the '' Reseda luteola'' plant, used for dyeing since at least the first millennium B.C. Luteolin was first isolated in pure f .... A cynaroside 7-O-glucosidase has been identified in the artichoke. Spectral data References {{flavone Flavone glucosides Catechols ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flavone
Flavone is an organic compound with the formula . A white solid, flavone is a derivative of chromone with a phenyl (Ph) substituent adjacent to the ether group. The compound is of little direct practical importance, but substituted derivatives, the flavones and flavonoids are a large class of nutritionally important natural products. Flavone can be prepared in the laboratory by cyclization of 2-hydrox acetophenone. Isomeric with flavone is isoflavone, where the phenyl group is adjacent to the ketone In organic chemistry, a ketone is an organic compound with the structure , where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group (a carbon-oxygen double bond C=O). The simplest ketone is acetone ( .... References {{Flavones ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cynaroside 7-O-glucosidase
Cynaroside (also known as luteoloside) is a flavone, a flavonoid-like chemical compound. It is a 7-O-glucoside of luteolin. Natural occurrences It can be found in '' Ferula varia'' and '' F. foetida'' in ''Campanula persicifolia'' and '' C. rotundifolia'', in the bamboo ''Phyllostachys nigra'', and in ''Teucrium gnaphalodes''. ; In food It can be found in dandelion (the highest concentration in the flowers, but also in the roots) and in ''Cynara scolymus'' (artichoke). Metabolism Flavone 7-O-beta-glucosyltransferase adds a glucose to luteolin Luteolin is a flavone, a type of flavonoid, with a yellow crystalline appearance. Luteolin is the main yellow dye from the '' Reseda luteola'' plant, used for dyeing since at least the first millennium B.C. Luteolin was first isolated in pure f .... A cynaroside 7-O-glucosidase has been identified in the artichoke. Spectral data References {{flavone Flavone glucosides Catechols ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass Spectrometry
Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a ''mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is used in many different fields and is applied to pure samples as well as complex mixtures. A mass spectrum is a type of plot of the ion signal as a function of the mass-to-charge ratio. These spectra are used to determine the elemental or isotopic signature of a sample, the masses of particles and of molecules, and to elucidate the chemical identity or structure of molecules and other chemical compounds. In a typical MS procedure, a sample, which may be solid, liquid, or gaseous, is ionization, ionized, for example by bombarding it with a Electron ionization, beam of electrons. This may cause some of the sample's molecules to break up into positively charged fragments or simply become positively charged without fragmenting. These ions (fragmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon-13 NMR
Carbon-13 (C13) nuclear magnetic resonance (most commonly known as carbon-13 NMR spectroscopy or 13C NMR spectroscopy or sometimes simply referred to as carbon NMR) is the application of nuclear magnetic resonance (NMR) spectroscopy to carbon. It is analogous to proton NMR ( NMR) and allows the identification of carbon atoms in an organic molecule just as proton NMR identifies hydrogen atoms. 13C NMR detects only the isotope. The main carbon isotope, does not produce an NMR signal. Although ca. 1 mln. times less sensitive than 1H NMR spectroscopy, 13C NMR spectroscopy is widely used for characterizing organic and organometallic compounds, primarily because 1H-decoupled 13C-NMR spectra are more simple, have a greater sensitivity to differences in the chemical structure, and, thus, are better suited for identifying molecules in complex mixtures. At the same time, such spectra lack quantitative information about the atomic ratios of different types of carbon nuclei, because n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proton NMR
Proton nuclear magnetic resonance (proton NMR, hydrogen-1 NMR, or 1H NMR) is the application of nuclear magnetic resonance in NMR spectroscopy with respect to hydrogen-1 nuclei within the molecules of a substance, in order to determine the structure of its molecules. In samples where natural hydrogen (H) is used, practically all the hydrogen consists of the isotope 1H (hydrogen-1; i.e. having a proton for a nucleus). Simple NMR spectra are recorded in solution, and solvent protons must not be allowed to interfere. Deuterated (deuterium = 2H, often symbolized as D) solvents especially for use in NMR are preferred, e.g. deuterated water, D2O, deuterated acetone, (CD3)2CO, deuterated methanol, CD3OD, deuterated dimethyl sulfoxide, (CD3)2SO, and deuterated chloroform, CDCl3. However, a solvent without hydrogen, such as carbon tetrachloride, CCl4 or carbon disulfide, CS2, may also be used. Historically, deuterated solvents were supplied with a small amount (typically 0.1%) of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NMR Spectroscopy
Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy or magnetic resonance spectroscopy (MRS), is a spectroscopic technique based on re-orientation of atomic nuclei with non-zero nuclear spins in an external magnetic field. This re-orientation occurs with absorption of electromagnetic radiation in the radio frequency region from roughly 4 to 900 MHz, which depends on the isotopic nature of the nucleus and increases proportionally to the strength of the external magnetic field. Notably, the resonance frequency of each NMR-active nucleus depends on its chemical environment. As a result, NMR spectra provide information about individual functional groups present in the sample, as well as about connections between nearby nuclei in the same molecule. As the NMR spectra are unique or highly characteristic to individual compounds and functional groups, NMR spectroscopy is one of the most important methods to identify molecular structures, particularly of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared
Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those of red light (the longest waves in the visible spectrum), so IR is invisible to the human eye. IR is generally (according to ISO, CIE) understood to include wavelengths from around to . IR is commonly divided between longer-wavelength thermal IR, emitted from terrestrial sources, and shorter-wavelength IR or near-IR, part of the solar spectrum. Longer IR wavelengths (30–100 μm) are sometimes included as part of the terahertz radiation band. Almost all black-body radiation from objects near room temperature is in the IR band. As a form of EMR, IR carries energy and momentum, exerts radiation pressure, and has properties corresponding to both those of a wave and of a particle, the photon. It was long known that fires e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molar Absorptivity
In chemistry, the molar absorption coefficient or molar attenuation coefficient () is a measurement of how strongly a chemical species absorbs, and thereby attenuates, light at a given wavelength. It is an intrinsic property of the species. The SI unit of molar absorption coefficient is the square metre per mole (), but in practice, quantities are usually expressed in terms of −1⋅cm−1 or L⋅mol−1⋅cm−1 (the latter two units are both equal to ). In older literature, the cm2/mol is sometimes used; 1 M−1⋅cm−1 equals 1000 cm2/mol. The molar absorption coefficient is also known as the molar extinction coefficient and molar absorptivity, but the use of these alternative terms has been discouraged by the IUPAC. Beer–Lambert law The absorbance of a material that has only one absorbing species also depends on the pathlength and the concentration of the species, according to the Beer–Lambert law :A = \varepsilon c\ell, where * is the ''molar absorption coef ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanometre
330px, Different lengths as in respect to the Molecule">molecular scale. The nanometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: nm), or nanometer (American spelling), is a unit of length in the International System of Units (SI), equal to one billionth ( short scale) or one thousand million (long scale) of a meter (0.000000001 m) and to 1000 picometres. One nanometre can be expressed in scientific notation as 1 × 10−9 m and as m. History The nanometre was formerly known as the "''millimicrometre''" – or, more commonly, the "''millimicron''" for short – since it is of a micrometer. It was often denoted by the symbol ''mμ'' or, more rarely, as ''μμ'' (however, ''μμ'' should refer to a ''millionth'' of a micron). Etymology The name combines the SI prefix '' nano-'' (from the Ancient Greek , ', "dwarf") with the parent unit name ''metre'' (from Greek , ', "unit of measurement"). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flavone 7-O-beta-glucosyltransferase
In enzymology, a flavone 7-O-beta-glucosyltransferase () is an enzyme that catalyzes the chemical reaction :UDP-glucose + 5,7,3',4'-tetrahydroxyflavone \rightleftharpoons UDP + 7-O-beta-D-glucosyl-5,7,3',4'-tetrahydroxyflavone Thus, the two substrates of this enzyme are UDP-glucose and 5,7,3',4'-tetrahydroxyflavone (luteolin), whereas its two products are UDP and 7-O-beta-D-glucosyl-5,7,3',4'-tetrahydroxyflavone (cynaroside). This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-glucose:5,7,3',4'-tetrahydroxyflavone 7-O-beta-D-glucosyltransferase. Other names in common use include UDP-glucose-apigenin beta-glucosyltransferase, UDP-glucose-luteolin beta-D-glucosyltransferase, uridine diphosphoglucose-luteolin glucosyltransferase, uridine diphosphoglucose-apigenin 7-O-glucosyltransferase, and UDP-glucosyltransferase. This enzyme participates in flavonoid biosynthesis Flavonoids are synt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
