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Flavonoids
Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans. Chemically, flavonoids have the general structure of a 15-carbon skeleton, which consists of two phenyl rings (A and B) and a heterocyclic ring (C, the ring containing the embedded oxygen). This carbon structure can be abbreviated C6-C3-C6. According to the IUPAC nomenclature, they can be classified into: *flavonoids or bioflavonoids *isoflavonoids, derived from 3-phenyl chromen-4-one (3-phenyl-1,4-benzopyrone) structure *neoflavonoids, derived from 4-phenylcoumarine (4-phenyl-1,2-benzopyrone) structure The three flavonoid classes above are all ketone-containing compounds and as such, anthoxanthins ( flavones and flavonols). This class was the first to be termed bioflavonoids. The terms flavonoid and bioflavonoid have also been more loosely used to describe non- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoflavonoid
Isoflavonoids are a class of flavonoid phenolic compounds, many of which are biologically active. Isoflavonoids and their derivatives are sometimes referred to as phytoestrogens, as many isoflavonoid compounds have biological effects via the estrogen receptor. Medically, isoflavonoids and related compounds have been used in many dietary supplements but the medical and scientific community is generally skeptical of their use. Recently, some natural isoflavonoids have been identified as toxins, including biliatresone which may cause biliary atresia when infants are exposed to the plant product. The isoflavonoid group is broad, and includes many structurally similar groups, including: * isoflavones * isoflavanones * isoflavans * pterocarpans * rotenoids Isoflavonoids are derived from the flavonoid biosynthesis pathway via liquiritigenin or naringenin. Chemical makeup While flavonoids (in the narrow sense) have the 2-phenylchromen-4-one backbone, isoflavonoids have the 3-phenyl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4-phenylcoumarin
Neoflavonoids are a class of polyphenolic compounds. While flavonoids (in the narrow sense) have the 2-phenylchromen-4-one backbone, neoflavonoids have the 4-phenylchromen backbone with no hydroxyl group substitution at position 2. Types Neoflavonoids include 4-arylcoumarins (neoflavones), 4-arylchromanes, dalbergiones and dalbergiquinols. * Neoflavones are derived from the 4-phenylcoumarin (or 4-aryl-coumarin) backbone (C15H12O2). The first neoflavone isolated from natural sources was calophyllolide from ''Calophyllum inophyllum'' seeds (1951). It is also known to found in bark and timber of Sri Lankan endemic plant ''Mesua thwaitesii''. * Neoflavenes possess the 4-phenylchromen backbone (C15H10O2). Dalbergichromene, extracted from the stem-bark and heartwood of ''Dalbergia sissoo'', is an example of such compounds Other examples * Coutareagenin (5-hydroxy-7-methoxy-4-(3,4-dihydroxyphenyl)-2H-benzo-1-pyran-2-on) found in ''Hintonia latiflora'' * Dalbergin * Nivetin isolated f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flavonol
Flavonols are a class of flavonoids that have the 3-hydroxyflavone backbone (IUPAC name : 3-hydroxy-2-phenylchromen-4-one). Their diversity stems from the different positions of the phenolic -OH groups. They are distinct from flavanols (with "a") such as catechin, another class of flavonoids. Flavonols are present in a wide variety of fruits and vegetables. In Western populations, estimated daily intake is in the range of 20–50 mg per day for flavonols. Individual intake varies depending on the type of diet consumed. The phenomenon of dual fluorescence (due to excited state intramolecular proton transfer or ESIPT) is induced by tautomerism of flavonols (and glucosides) and could contribute to plant UV protection and flower colour. Besides being a subclass of flavonoids, flavonols are suggested by a study of cranberry juice to play a role along with proanthocyanidins, in the juice's ability to block bacterial adhesion, demonstrated by the compressing the fimbria of ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neoflavonoids
Neoflavonoids are a class of polyphenolic compounds. While flavonoids (in the narrow sense) have the 2-phenylchromen-4-one backbone, neoflavonoids have the 4-phenylchromen backbone with no hydroxyl group substitution at position 2. Types Neoflavonoids include 4-arylcoumarins (neoflavones), 4-arylchromanes, dalbergiones and dalbergiquinols. * Neoflavones are derived from the 4-phenylcoumarin (or 4-aryl-coumarin) backbone (C15H12O2). The first neoflavone isolated from natural sources was calophyllolide from ''Calophyllum inophyllum'' seeds (1951). It is also known to found in bark and timber of Sri Lankan endemic plant ''Mesua thwaitesii''. * Neoflavenes possess the 4-phenylchromen backbone (C15H10O2). Dalbergichromene, extracted from the stem-bark and heartwood of ''Dalbergia sissoo'', is an example of such compounds Other examples * Coutareagenin (5-hydroxy-7-methoxy-4-(3,4-dihydroxyphenyl)-2H-benzo-1-pyran-2-on) found in ''Hintonia latiflora'' * Dalbergin * Nivetin isolated f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyphenol
Polyphenols () are a large family of naturally occurring organic compounds characterized by multiples of phenol units. They are abundant in plants and structurally diverse. Polyphenols include flavonoids, tannic acid, and ellagitannin, some of which have been used historically as dyes and for tanning garments. Etymology The name derives from the Ancient Greek word (''polus'', meaning "many, much") and the word phenol which refers to a chemical structure formed by attaching to an aromatic benzenoid (phenyl) ring to a hydroxyl (-OH) group as is found in alcohols (hence the ''-ol'' suffix). The term polyphenol has been in use at least since 1894. Definition The term polyphenol is not well-defined, but is generally agreed that they are natural products "having a polyphenol structure (i.e., several hydroxyl groups on aromatic rings)" including four principal classes: "phenolic acids, flavonoids, stilbenes, and lignans". *Flavonoids include flavones, flavonols, flavanols, f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Metabolite
Secondary metabolites, also called specialised metabolites, toxins, secondary products, or natural products, are organic compounds produced by any lifeform, e.g. bacteria, fungi, animals, or plants, which are not directly involved in the normal growth, development, or reproduction of the organism. Instead, they generally mediate ecological interactions, which may produce a selective advantage for the organism by increasing its survivability or fecundity. Specific secondary metabolites are often restricted to a narrow set of species within a phylogenetic group. Secondary metabolites often play an important role in plant defense against herbivory and other interspecies defenses. Humans use secondary metabolites as medicines, flavourings, pigments, and recreational drugs. The term secondary metabolite was first coined by Albrecht Kossel, a 1910 Nobel Prize laureate for medicine and physiology in 1910. 30 years later a Polish botanist Friedrich Czapek described secondary metabolit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhizobia
Rhizobia are diazotrophic bacteria that fix nitrogen after becoming established inside the root nodules of legumes (Fabaceae). To express genes for nitrogen fixation, rhizobia require a plant host; they cannot independently fix nitrogen. In general, they are gram negative, motile, non-sporulating rods. Rhizobia are a "group of soil bacteria that infect the roots of legumes to form root nodules". Rhizobia are found in the soil and after infection, produce nodules in the legume where they fix nitrogen gas (N2) from the atmosphere turning it into a more readily useful form of nitrogen. From here, the nitrogen is exported from the nodules and used for growth in the legume. Once the legume dies, the nodule breaks down and releases the rhizobia back into the soil where they can live individually or reinfect a new legume host. History The first known species of rhizobia, '' Rhizobium leguminosarum'', was identified in 1889, and all further species were initially placed in the ''Rhiz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eriodictyol
Eriodictyol is a bitter-masking flavanone, a flavonoid extracted from yerba santa (''Eriodictyon californicum''), a plant native to North America. Eriodictyol is one of the four flavanones identified in this plant as having taste-modifying properties, the other three being homoeriodictyol, its sodium salt, and sterubin. Eriodictyol was also found in the twigs of ''Millettia duchesnei'', in ''Eupatorium arnottianum'', and its glycosides (eriocitrin) in lemons and rose hips The rose hip or rosehip, also called rose haw and rose hep, is the accessory fruit of the various species of rose plant. It is typically red to orange, but ranges from dark purple to black in some species. Rose hips begin to form after pollinat ... (''Rosa canina''). References {{Flavanone Flavanones Bitter-masking compounds Catechols Resorcinols ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hesperidin
Hesperidin is a flavanone glycoside found in citrus fruits. Its aglycone form is called hesperetin. Its name is derived from the word "hesperidium", for fruit produced by citrus trees. Hesperidin was first isolated in 1828 by French chemist M. Lebreton from the white inner layer of citrus peels (mesocarp, albedo). Hesperidin is believed to play a role in plant defense. Sources ''Rutaceae'' * 700–2,500 ppm in fruit of ''Citrus aurantium'' (bitter orange, petitgrain) * in orange juice (''Citrus sinensis'') * in ''Zanthoxylum gilletii'' * in lemon * in lime * in leaves of ''Agathosma serratifolia'' ''Lamiaceae'' Peppermint contains hesperidin. Content in foods Approximate hesperidin content per 100 ml * 481 mg peppermint, dried * 44 mg blood orange, pure juice * 26 mg orange, pure juice * 18 mg lemon, pure juice * 14 mg lime, pure juice * 1 mg grapefruit, pure juice Metabolism Hesperidin 6-''O''-α--rhamnosyl-β--glucosidase, an enzyme ... [...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 susbstituted 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-hydroxacetophenone. Isomeric with flavone is isoflavone, where the phenyl group is adjacent to the ketone In organic chemistry, a ketone is a functional group with the structure R–C(=O)–R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group –C(=O)– (which contains a carbon-oxygen double bo .... References {{Flavones ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthoxanthin
Anthoxanthins ( flavones and flavonols)Isolation of a UDP-glucose: Flavonoid 5-O-glucosyltransferase gene and expression analysis of anthocyanin biosynthetic genes in herbaceous peony (Paeonia lactiflora Pall.). Da Qiu Zhao, Chen Xia Han, Jin Tao Ge and Jun Tao, Electronic Journal of Biotechnology, 15 November 2012, Volume 15, Number 6, are a type of flavonoid pigments in plants. Anthoxanthins are water-soluble pigments which range in color from white or colorless to a creamy to yellow, often on petals of flowers. These pigments are generally whiter in an acid medium and yellowed in an alkaline medium. They are very susceptible to color changes with minerals and metal ions, similar to anthocyanins. Uses As with all flavonoids, anthoxanthins have antioxidant properties and are important for nutrition. They are sometimes used as food additives to add color or flavor to foods. One of the most well-known anthoxanthins is quercetin Quercetin is a plant flavonol from the flavonoi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coumarine
Coumarin () or 2''H''-chromen-2-one is an aromatic organic chemical compound with formula . Its molecule can be described as a benzene molecule with two adjacent hydrogen atoms replaced by a lactone-like chain , forming a second six-membered heterocycle that shares two carbons with the benzene ring. It can be placed in the benzopyrone chemical class and considered as a lactone. Coumarin is a colorless crystalline solid with a sweet odor resembling the scent of vanilla and a bitter taste. It is found in many plants, where it may serve as a chemical defense against predators. By inhibiting synthesis of vitamin K, a related compound is used as the prescription drug warfarin – an anticoagulant – to inhibit formation of blood clots, deep vein thrombosis, and pulmonary embolism. Etymology Coumarin is derived from ''coumarou'', the French word for the tonka bean. The word ''tonka'' for the tonka bean is taken from the Galibi (Carib) tongue spoken by natives of French Guia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
