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β-damascenone
Damascenones are a series of closely related chemical compounds that are components of a variety of essential oils. The damascenones belong to a family of chemicals known as rose ketones, which also includes damascones and ionones. ''beta''-Damascenone is a major contributor to the aroma of roses, despite its very low concentration, and is an important fragrance chemical used in perfumery. The damascenones are derived from the degradation of carotenoids. In 2008, (E)-β-damascenone was identified as a primary odorant in Kentucky bourbon. Biosynthesis The biosynthesis for β-damascenone begins with farnesyl pyrophosphate (FPP) and isopentenyl pyrophosphate (IPP) reacting to produce geranylgeranyl pyrophosphate (GGPP) Figure 1. Next two molecules of GGPP are condensed together to produce phytoene by removal of diphosphate and a proton shift catalyzed by the enzyme phytoene synthase (PSY). Phytoene then goes through a series of desaturation reactions using the enzyme Phytoene de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carotenoid
Carotenoids () are yellow, orange, and red organic pigments that are produced by plants and algae, as well as several bacteria, archaea, and fungi. Carotenoids give the characteristic color to pumpkins, carrots, parsnips, corn, tomatoes, canaries, flamingos, salmon, lobster, shrimp, and daffodils. Over 1,100 identified carotenoids can be further categorized into two classes xanthophylls (which contain oxygen) and carotenes (which are purely hydrocarbons and contain no oxygen). All are derivatives of tetraterpenes, meaning that they are produced from 8 isoprene units and contain 40 carbon atoms. In general, carotenoids absorb wavelengths ranging from 400 to 550 nanometers (violet to green light). This causes the compounds to be deeply colored yellow, orange, or red. Carotenoids are the dominant pigment in autumn leaf coloration of about 15-30% of tree species, but many plant colors, especially reds and purples, are due to polyphenols. Carotenoids serve two key roles in p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Essential Oil
An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the oil of the plant from which they were extracted, such as oil of clove. An essential oil is essential in the sense that it contains the essence of the plant's fragrance—the characteristic fragrance of the plant from which it is derived. The term "essential" used here does ''not'' mean required or usable by the human body, as with the terms essential amino acid or essential fatty acid, which are so called because they are nutritionally required by a living organism. Essential oils are generally extracted by distillation, often by using steam. Other processes include expression, solvent extraction, '' sfumatura'', absolute oil extraction, resin tapping, wax embedding, and cold pressing. They are used in perfumes, cosmetics, soaps, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lycopene
Lycopene is an organic compound classified as a tetraterpene and a carotene. Lycopene (from the Neo-Latin '' Lycopersicon'', the name of a former tomato genus) is a bright red carotenoid hydrocarbon found in tomatoes and other red fruits and vegetables. Occurrence Aside from tomatoes or tomato products like ketchup, it is found in watermelons, grapefruits, red guavas, and baked beans. It has no vitamin A activity. In plants, algae, and other photosynthetic organisms, lycopene is an intermediate in the biosynthesis of many carotenoids, including beta-carotene, which is responsible for yellow, orange, or red pigmentation, photosynthesis, and photoprotection. Like all carotenoids, lycopene is a tetraterpene. It is soluble in fat, but insoluble in water. Eleven conjugated double bonds give lycopene its deep red color. Owing to the strong color, lycopene is used as a food coloring (registered as E160d) and is approved for use in the US, Australia and New Zealand (register ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylenic Diol Mechanism
In organic chemistry, the term acetylenic designates *A doubly unsaturated position (''sp''-hybridized) on a molecular framework, for instance in an alkyne such as acetylene; *An ethynyl fragment, HC\equivC–, or substituted homologue. See also * Allylic * Propargylic * Vinylic Organic chemistry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neoxanthin Synthesis
Neoxanthin is a carotenoid and xanthophyll. In plants, it is an intermediate in the biosynthesis of the plant hormone abscisic acid. It is often present in two forms: all-trans and 9-cis isomers. It is produced from violaxanthin, but a suspected neoxanthin synthase is still to be confirmed. Two different genes were confirmed to be implied in violaxanthin conversion to neoxanthin in Arabidopsis and tomato. It has a specific role in protection against photooxidative stress. It is a major xanthophyll found in green leafy vegetables such as spinach Spinach (''Spinacia oleracea'') is a leafy green flowering plant native to Central Asia, Central and Western Asia. It is of the order Caryophyllales, family Amaranthaceae, subfamily Chenopodioideae. Its leaves are a common vegetable consumed eit .... References {{Carotenoids Carotenoids Epoxides Cumulated dienes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neoxanthin Synthase
In enzymology, a neoxanthin synthase () is an enzyme that catalyzes the chemical reaction: :violaxanthin \rightleftharpoons neoxanthin Hence, this enzyme has one substrate, violaxanthin, and one product, neoxanthin. This enzyme belongs to the family of isomerases, specifically a class of other intramolecular oxidoreductases. The systematic name A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection. Systematic names are usually part of a nomenclature. A semisystematic name or semitrivi ... of this enzyme class is violaxanthin---neoxanthin isomerase (epoxide-opening). This enzyme is also called NSY. This enzyme participates in carotenoid biosynthesis - general. References * * EC 5.3.99 Enzymes of unknown structure {{isomerase-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Violaxanthin
Violaxanthin is a xanthophyll pigment with an orange color found in a variety of plants. Violaxanthin is the product of the epoxidation of zeaxanthin where the oxygen atoms are from reactive oxygen species (ROS). Such ROS's arise when a plant is subject to solar radiation so intense that the light cannot all be absorbed by the chlorophyll. Food coloring Violaxanthin is used as a food coloring under the E number E161e and INS number The International Numbering System for Food Additives (INS) is an international naming system for food additives, aimed at providing a short designation of what may be a lengthy actual name."Class Names and the International Numbering System for Fo ... 161e. The coloring is not approved for use in food in the EU or the United States, but is allowed in Australia and New Zealand.Australia New Zealand Food Standards Code Violaxanthin cycle Violaxanthin is a participant in the violaxanthin cycle. : References {{Carotenoids Carotenoids Epoxides Fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeaxanthin Epoxidase
Zeaxanthin epoxidase (, ''Zea-epoxidase'') is an enzyme with systematic name ''zeaxanthin,NAD(P)H:oxygen oxidoreductase''. This enzyme catalyses the following chemical reaction A chemical reaction is a process that leads to the chemistry, chemical transformation of one set of chemical substances to another. When chemical reactions occur, the atoms are rearranged and the reaction is accompanied by an Gibbs free energy, ... : zeaxanthin + 2 NAD(P)H + 2 H+ + 2 O2 \rightleftharpoons violaxanthin + 2 NAD(P)+ + 2 H2O (overall reaction) :(1a) zeaxanthin + NAD(P)H + H+ + O2 \rightleftharpoons antheraxanthin + NAD(P)+ + H2O :(1b) antheraxanthin + NAD(P)H + H+ + O2 \rightleftharpoons violaxanthin + NAD(P)+ + H2O Zeaxanthin epoxidase is a flavoprotein (FAD) that is active under conditions of low light. References External links * {{Portal bar, Biology, border=no EC 1.14.13 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeaxanthin
Zeaxanthin is one of the most common carotenoids in nature, and is used in the xanthophyll cycle. Synthesized in plants and some micro-organisms, it is the pigment that gives paprika (made from bell peppers), corn, saffron, goji ( wolfberries), and many other plants and microbes their characteristic color. The name (pronounced ''zee-uh-zan'-thin'') is derived from ''Zea mays'' (common yellow maize corn, in which zeaxanthin provides the primary yellow pigment), plus ''xanthos'', the Greek word for "yellow" (see xanthophyll). Xanthophylls such as zeaxanthin are found in highest quantity in the leaves of most green plants, where they act to modulate light energy and perhaps serve as a non-photochemical quenching agent to deal with triplet chlorophyll (an excited form of chlorophyll) which is overproduced at high light levels during photosynthesis. Zeaxanthin in guard cells acts as a blue light photoreceptor which mediates the stomatal opening. Animals derive zeaxanthin from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
