|
Paracoumaryl Alcohol
Paracoumaryl alcohol is a phytochemical, one of the monolignols. It is a white solid. ''p''-Coumaryl alcohol is a major precursor to lignin or lignans. Biosynthesis and occurrence It is synthesized via the phenylpropanoid biochemical pathway. Esters of ''p''-coumaryl alcohol and fatty acids are the basis of epicuticular waxes covering the surfaces of apples. ''p''-Coumaryl alcohol is an intermediate in biosynthesis of chavicol, stilbenoids, and coumarin 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 an unsaturated lactone ring , forming a second six-me .... External links Molecule of the week: p-coumaryl alcohol References {{Monolignols Monolignols 4-Hydroxyphenyl compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytochemical
Phytochemicals are naturally-occurring chemicals present in or extracted from plants. Some phytochemicals are nutrients for the plant, while others are metabolites produced to enhance plant survivability and reproduction. The fields of extracting phytochemicals for manufactured products or applying scientific methods to study phytochemical properties are called ''phytochemistry''. An individual who uses phytochemicals in food chemistry manufacturing or research is a ''phytochemist''. Phytochemicals without a nutrient definition have no confirmed biological activities or proven health benefits when consumed in plant foods. Once phytochemicals in a food enter the digestion process, the fate of individual phytochemicals in the body is unknown due to extensive metabolism of the food in the gastrointestinal tract, producing phytochemical metabolites with different biological properties from those of the parent compound that may have been tested in vitro. Further, the bioavaila ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monolignol
Monolignols, also called lignols, are the source materials for biosynthesis of both lignans and lignin and consist mainly of paracoumaryl alcohol (H), coniferyl alcohol (G) and sinapyl alcohol (S). These monolignols differ in their degree of methoxylation of the aromatic ring. The monolignols are derived from the amino acid phenylalanine via the phenylpropanoid pathway involving various enzymes. Phenylalanine is first converted to paracoumaryl alcohol (H), which is subsequently elaborated to coniferyl alcohol (G) and sinapyl alcohol (S). This reaction happens in the cytosol, while the polymerization of the monolignols occurs in the apoplast to which the monolignols have to be transported through the cell membrane. The monolignols have been found as monolignol-4-O-β-d- glucosides, which might be their major way of storage. Another theory for this conversion is that is improving the transportation of the monolignols. The polymerization consists of oxidative coupling reactions, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lignin
Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity and do not rot easily. Chemically, lignins are polymers made by cross-linking phenolic precursors. History Lignin was first mentioned in 1813 by the Swiss botanist A. P. de Candolle, who described it as a fibrous, tasteless material, insoluble in water and alcohol but soluble in weak alkaline solutions, and which can be precipitated from solution using acid. He named the substance "lignine", which is derived from the Latin word '' lignum'', meaning wood. It is one of the most abundant organic polymers on Earth, exceeded only by cellulose and chitin. Lignin constitutes 30% of terrestrial non-fossil organic carbon on Earth, and 20 to 35% of the dry mass of wood. Lignin is present in red algae, which suggest that the common ancestor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lignan
The lignans are a large group of low molecular weight polyphenols found in plants, particularly seeds, whole grains, and vegetables. The name derives from the Latin word for "wood". Lignans are precursors to phytoestrogens. They may play a role as antifeedants in the defense of seeds and plants against herbivores. Biosynthesis and metabolism Lignans and lignin differ in their molecular weight, the former being small and soluble in water, the latter being high polymers that are undigestable. Both are polyphenolic substances derived by oxidative coupling of monolignols. Thus, most lignans feature a C18 cores, resulting from the dimerization of C9 precursors. The coupling of the lignols occurs at C8. Eight classes of lignans are: "furofuran, furan, dibenzylbutane, dibenzylbutyrolactone, aryltetralin, arylnaphthalene, dibenzocyclooctadiene, and dibenzylbutyrolactol." Many lignans are metabolized by mammalian gut microflora, producing so-called enterolignans. Food sources Fl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenylpropanoid
The phenylpropanoids are a diverse family of organic compounds that are biosynthesized by plants from the amino acids phenylalanine and tyrosine in the shikimic acid pathway. Their name is derived from the six-carbon, aromatic phenyl group and the three-carbon propene tail of coumaric acid, which is the central intermediate in phenylpropanoid biosynthesis. From 4-Coumaroyl-CoA, 4-coumaroyl-CoA emanates the biosynthesis of myriad natural products including Monolignol, lignols (precursors to lignin and lignocellulose), flavonoids, isoflavonoids, coumarins, aurones, stilbenes, catechin, and phenylpropanoids. The coumaroyl component is produced from cinnamic acid. Phenylpropanoids are found throughout the plant kingdom, where they serve as essential components of a number of structural polymers, provide protection from ultraviolet light, defend against herbivores and pathogens, and also mediate plant-pollinator interactions as floral pigments and scent compounds. Hydroxycinnamic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biochemical Pathway
In biochemistry, a metabolic pathway is a linked series of chemical reactions occurring within a cell. The reactants, products, and intermediates of an enzymatic reaction are known as metabolites, which are modified by a sequence of chemical reactions catalyzed by enzymes. In most cases of a metabolic pathway, the product of one enzyme acts as the substrate for the next. However, side products are considered waste and removed from the cell. Different metabolic pathways function in the position within a eukaryotic cell and the significance of the pathway in the given compartment of the cell. For instance, the electron transport chain and oxidative phosphorylation all take place in the mitochondrial membrane. In contrast, glycolysis, pentose phosphate pathway, and fatty acid biosynthesis all occur in the cytosol of a cell. There are two types of metabolic pathways that are characterized by their ability to either synthesize molecules with the utilization of energy ( anab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ester
In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distinctive functional group. Analogues derived from oxygen replaced by other chalcogens belong to the ester category as well. According to some authors, organyl derivatives of acidic hydrogen of other acids are esters as well (e.g. amides), but not according to the IUPAC. Glycerides are fatty acid esters of glycerol; they are important in biology, being one of the main classes of lipids and comprising the bulk of animal fats and vegetable oils. Lactones are cyclic carboxylic esters; naturally occurring lactones are mainly 5- and 6-membered ring lactones. Lactones contribute to the aroma of fruits, butter, cheese, vegetables like celery and other foods. Esters can be formed from oxoacids (e.g. esters of acetic acid, carbonic acid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fatty Acid
In chemistry, in particular in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated and unsaturated compounds#Organic chemistry, saturated or unsaturated. Most naturally occurring fatty acids have an Branched chain fatty acids, unbranched chain of an even number of carbon atoms, from 4 to 28. Fatty acids are a major component of the lipids (up to 70% by weight) in some species such as microalgae but in some other organisms are not found in their standalone form, but instead exist as three main classes of esters: triglycerides, phospholipids, and cholesteryl esters. In any of these forms, fatty acids are both important diet (nutrition), dietary sources of fuel for animals and important structural components for cell (biology), cells. History The concept of fatty acid (''acide gras'') was introduced in 1813 by Michel Eugène Chevreul, though he initially used some variant terms: ''graisse acide'' and ''acide huileux'' ("acid fat" and "oi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apple
An apple is a round, edible fruit produced by an apple tree (''Malus'' spp.). Fruit trees of the orchard or domestic apple (''Malus domestica''), the most widely grown in the genus, are agriculture, cultivated worldwide. The tree originated in Central Asia, where its wild ancestor, ''Malus sieversii'', is still found. Apples have been grown for thousands of years in Eurasia before they were introduced to North America by European colonization of the Americas, European colonists. Apples have cultural significance in many mythological, mythologies (including Norse mythology, Norse and Greek mythology, Greek) and religions (such as Christianity in Europe). Apples grown from seeds tend to be very different from those of their parents, and the resultant fruit frequently lacks desired characteristics. For commercial purposes, including botanical evaluation, apple cultivars are propagated by clonal grafting onto rootstocks. Apple trees grown without rootstocks tend to be larger and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biosynthesis
Biosynthesis, i.e., chemical synthesis occurring in biological contexts, is a term most often referring to multi-step, enzyme-Catalysis, catalyzed processes where chemical substances absorbed as nutrients (or previously converted through biosynthesis) serve as enzyme substrate (chemistry), substrates, with conversion by the living organism either into simpler or more complex Product (chemistry), products. Examples of biosynthetic pathways include those for the production of amino acids, lipid membrane components, and nucleotides, but also for the production of all classes of biological macromolecules, and of acetyl-coenzyme A, adenosine triphosphate, nicotinamide adenine dinucleotide and other key intermediate and transactional molecules needed for metabolism. Thus, in biosynthesis, any of an array of Chemical compound, compounds, from simple to complex, are converted into other compounds, and so it includes both the catabolism and anabolism (building up and breaking down) of comple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chavicol
Chavicol (''p''-allylphenol) is a natural phenylpropene, a type of organic compound. Its chemical structure consists of a benzene ring substituted with a hydroxy group and a propenyl group. It is a colorless liquid found together with terpenes in betel oil. Properties and reactions Chavicol is miscible with alcohol, ether, and chloroform. Dimerization of chavicol gives the neo-lignan magnolol. Uses Chavicol is used as an odorant in perfumery and as a flavor. It is found in many essential oils, including anise and gardenia. Biosynthesis Chavicol is formed in sweet basil (''Ocimum Basilicum'') by the phenylpropanoid pathway via ''p''-coumaryl alcohol. The allylic alcohol in ''p''-coumaryl alcohol is converted into a leaving group. This then leaves thus forming a cation, this cation can be regarded as a quinone methide which then is reduced by NADPH to form either anol or chavicol. : See also * Estragole, the methyl ether * Safrole Safrole is an organic compound with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stilbenoid
Stilbenoids are hydroxylated derivatives of stilbene. They have a C6–C2–C6 structure. In biochemical terms, they belong to the family of phenylpropanoids and share most of their biosynthesis pathway with Chalconoid, chalcones. Most stilbenoids are produced by plants, and the only known exception is the antimicrobial stilbenoid drug tapinarof which is biosynthesized by the Gram-negative bacterium ''Photorhabdus luminescens.'' Chemistry Stilbenoids are hydroxylated derivatives of stilbene and have a C6–C2–C6 structure. They belong to the family of phenylpropanoids and share most of their biosynthesis pathway with Chalconoid, chalcones. Under UV irradiation, stilbene and its derivatives undergo intramolecular cyclization, called stilbene photocyclization to form dihydrophenanthrenes. Oligomeric forms are known as oligostilbenoids. Types ;Aglycones * Piceatannol in the roots of Norway spruces * Pinosylvin is a fungal toxin protecting wood from fungal infection, found in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
