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2,6-dimethoxyphenol
Syringol is the organic compound with the formula HO(CH3O)2C6H3. The molecule is a phenol, with methoxy groups in the flanking (2 and 6) positions. It is the symmetrically dimethylated derivative of pyrogallol. It is a colorless solid, although typical samples are brown owing to air-oxidized impurities. Together with guaiacol, syringol and its derivatives are produced by the pyrolysis of lignin. Specifically, syringol is derived from the thermal decomposition of the sinapyl alcohol component. As such, syringol is an important component of wood smoke. Syringyl/guaiacyl ratio Lignin, comprising a major fraction of biomass, is sometimes classified according to the syringyl component. Pyrolysis of lignin derived from sinapyl alcohol affords syringol. The conversion involves replacement of the propenyl alcohol substituent of the sinapyl alcohol by hydrogen. A high syringyl (or S) content is indicative of lignin from angiosperms. In contrast, pyrolysis of lignin from gymnosperms gi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canolol
Canolol is a phenolic compound found in crude canola oil. It is produced by decarboxylation of sinapic acid during canola seed roasting.Isolation and Identification of a Potent Radical Scavenger (Canolol) from Roasted High Erucic Mustard Seed Oil from Nepal and Its Formation during Roasting. Kshitij Shrestha, Christian V Stevens, Bruno De Meulenaer, J. Agric. Food Chem., 2012, 60 (30), pp 7506–7512, See also *Phenolic content in wine *Syringaldehyde *Syringol *Syringic acid *Acetosyringone *Sinapyl alcohol *Sinapaldehyde *Sinapinic acid *Sinapine Sinapine is an alkaloidal amine found in some seeds, particularly oil seeds of plants in the family Brassicaceae. It is the choline ester of sinapic acid. Sinapine was discovered by Etienne Ossian Henry in 1825. Occurrence Sinapine typically ... References O-methylated natural phenols Vinyl compounds Vegetable oils {{phenol-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetosyringone
Acetosyringone is a phenolic natural product and a chemical compound related to acetophenone and 2,6-dimethoxyphenol. It was first described in relation to lignan/phenylpropanoid-type phytochemicals, with isolation from a variety of plant sources, in particular, in relation to wounding and other physiologic changes. Occurrence and biological role Historically, this substance has been best known for its involvement in plant-pathogen recognition, especially its role as a signal attracting and transforming unique, oncogenic bacteria in genus ''Agrobacterium''. The ''virA'' gene on the Ti plasmid of ''Agrobacterium tumefaciens'' and the Ri plasmid of ''Agrobacterium rhizogenes'' is used by these soil bacteria to infect plants, via its encoding for a receptor for acetosyringone and other phenolic phytochemicals exuded by plant wounds. This compound also allows higher transformation efficiency in plants, as shown in ''A. tumefaciens''-mediated transformation procedures, and so is of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinapyl Alcohol
Sinapyl alcohol is an organic compound structurally related to cinnamic acid. It is biosynthetized via the phenylpropanoid biochemical pathway, its immediate precursor being sinapaldehyde. This phytochemical is one of the monolignols, which are precursor to lignin or lignans. It is also a biosynthetic precursor to various stilbenoids and coumarins. See also *Sinapinic acid *Syringol *Syringaldehyde *Syringic acid *Acetosyringone *Sinapine *Canolol *Phenolic content in wine The phenolic content in wine refers to the phenolic compounds—natural phenol and polyphenols—in wine, which include a large group of several hundred chemical compounds that affect the taste, color and mouthfeel of wine. These compounds include ... References {{DEFAULTSORT:Sinapyl Alcohol Monolignols Ethers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrolysis Oil
Pyrolysis oil, sometimes also known as bio-crude or bio-oil, is a synthetic fuel under investigation as substitute for petroleum. It is obtained by heating dried biomass without oxygen in a reactor at a temperature of about with subsequent cooling. Pyrolysis oil is a kind of tar and normally contains levels of oxygen too high to be considered a pure hydrocarbon. This high oxygen content results in non-volatility, corrosiveness, immiscibility with fossil fuels, thermal instability, and a tendency to polymerize when exposed to air. As such, it is distinctly different from petroleum products. Removing oxygen from bio-oil or nitrogen from algal bio-oil is known as upgrading. Standards There are few standards for pyrolysis oil because of limited efforts to produce it. One of the few standards is from ASTM. Feedstock decomposition Pyrolysis is a well established technique for decomposition of organic material at elevated temperatures in the absence of oxygen into oil and other c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinapine
Sinapine is an alkaloidal amine found in some seeds, particularly oil seeds of plants in the family Brassicaceae. It is the choline ester of sinapic acid. Sinapine was discovered by Etienne Ossian Henry in 1825. Occurrence Sinapine typically occurs in the outer seed coat of oil crops and is plentiful in some types of press cake leftover after vegetable oil extraction. Typical oil seed cake residues high in sinapine include ''Brassica juncea'' (1.22% by mass), and rapeseed (0.39-1.06% by mass). Isolation The typical protocol for extracting Sinapine from seed cakes entails defatting the cake with hexane via a Soxhlet apparatus followed by extraction with 70% methanol held at 75 °C. Metabolism Sinapine esterase is an enzyme whose two substrates are sinapine and H2O and whose two products are sinapic acid and choline. Sinapoylglucose—choline O-sinapoyltransferase is an enzyme whose two substrates are 1-''O''-sinapoyl-β-D-glucose and choline, whereas its two products ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinapinic Acid
Sinapinic acid, or sinapic acid (Sinapine - Origin: L. Sinapi, sinapis, mustard, Gr., cf. F. Sinapine.), is a small naturally occurring hydroxycinnamic acid. It is a member of the phenylpropanoid family. It is a commonly used matrix in MALDI mass spectrometry. It is a useful matrix for a wide variety of peptides and proteins. It serves well as a matrix for MALDI due to its ability to absorb laser radiation and to also donate protons (H+) to the analyte of interest. Sinapic acid can form dimers with itself (one structure) and ferulic acid (three different structures) in cereal cell walls and therefore may have a similar influence on cell-wall structure to that of the diferulic acids. Sinapine is an alkaloidal amine found in black mustard seeds. It is considered a choline ester of sinapinic acid. Natural occurrences Sinapinic acid can be found in wine and vinegar. Metabolism Sinapate 1-glucosyltransferase is an enzyme that uses UDP-glucose and sinapate to produce UDP and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinapaldehyde
Sinapaldehyde is an organic compound with the formula HO(CH3O)2C6H2CH=CHCHO. It is a derivative of cinnamaldehyde, featuring one hydroxy group and two methoxy groups as substituents. It is an intermediate in the formation of sinapyl alcohol, a lignol that is a major precursor to lignin. Biosynthetic role In sweetgum (''Liquidambar styraciflua''), sinapaldehyde arises in two steps from coniferyl aldehyde beginning with hydroxylation mediated by coniferyl aldehyde 5-hydroxylase. The diphenol is then methylated at the 5-OH by the action of caffeate ''O''-methyltransferase. Sinapaldehyde is reduced to the alcohol by the action of dehydrogenase enzymes. In ''Arabidopsis thaliana'', the enzyme dihydroflavonol 4-reductase uses NADP+ to reduce sinapaldehyde to sinapyl alcohol. It is found in ''Senra incana'' (Hibisceae). It is a low molecular weight phenol that is susceptible to extraction from cork stoppers into wine.Polyphenolic Composition of ''Quercus suber'' Cork from Different ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syringic Acid
Syringic acid is a naturally occurring phenolic compound and dimethoxybenzene that is commonly found as a plant metabolite. Natural occurrence Syringic acid can be found in several plants including ''Ardisia elliptica'' and '' Schumannianthus dichotomus''. Synthesis Syringic acid can be prepared by selectively hydrolyzing ( demethylating) eudesmic acid with 20% sulfuric acid. Presence in food Syringic acid can be found in several fruits including olives, dates, spices, pumpkin, grapes, acai palm, honey, red wine, among others. Its presence in the ancient Egyptian drink shedeh could confirm it was made out of grape, as syringic acid is released by the breakdown of the compound malvidin, also found in red wine. It is also found in vinegar. Applications Various studies have found syringic acid to exhibit useful pharmaceutical properties such as anti-oxidant, anti-microbial, anti-inflammation, anti-cancer, and anti-diabetic. Syringic acid can be enzymatically polymerise ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syringaldehyde
Syringaldehyde is an organic compound that occurs in trace amounts widely in nature. Some species of insects use syringaldehyde in their chemical communication systems. ''Scolytus multistriatus'' uses it as a signal to find a host tree during oviposition. Because it contains many functional groups, it can be classified in many ways - aromatic, aldehyde, phenol. It is a colorless solid (impure samples appear yellowish) that is soluble in alcohol and polar organic solvents. Its refractive index is 1.53. Natural sources Syringaldehyde can be found naturally in the wood of spruce and maple trees. Syringaldehyde is also formed in oak barrels and extracted into whisky, which it gives spicy, smoky, hot and smoldering wood aromas. Preparation This compound may be prepared from syringol by the Duff reaction: : See also *Phenolic content in wine *Syringol *Syringic acid *Acetosyringone *Sinapyl alcohol *Sinapinic acid *Sinapaldehyde *Sinapine *Canolol Canolol is a phenolic comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenolic Content In Wine
The phenolic content in wine refers to the phenolic compounds—natural phenol and polyphenols—in wine, which include a large group of several hundred chemical compounds that affect the taste, color and mouthfeel of wine. These compounds include phenolic acids, stilbenoids, flavonols, dihydroflavonols, anthocyanins, flavanol monomers (catechins) and flavanol polymers (proanthocyanidins). This large group of natural phenols can be broadly separated into two categories, flavonoids and non-flavonoids. Flavonoids include the anthocyanins and tannins which contribute to the color and mouthfeel of the wine. The non-flavonoids include the stilbenoids such as resveratrol and phenolic acids such as benzoic, caffeic and cinnamic acids. Origin of the phenolic compounds The natural phenols are not evenly distributed within the fruit. Phenolic acids are largely present in the pulp, anthocyanins and stilbenoids in the skin, and other phenols (catechins, proanthocyanidins and flavonols) in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plywood
Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured boards which include medium-density fibreboard (MDF), oriented strand board (OSB) and particle board (chipboard). All plywoods bind resin and wood fibre sheets (cellulose cells are long, strong and thin) to form a composite material. This alternation of the grain is called ''cross-graining'' and has several important benefits: it reduces the tendency of wood to split when nailed at the edges; it reduces expansion and shrinkage, providing improved dimensional stability; and it makes the strength of the panel consistent across all directions. There is usually an odd number of plies, so that the sheet is balanced—this reduces warping. Because plywood is bonded with grains running against one another and with an odd number of composite part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adhesive
Adhesive, also known as glue, cement, mucilage, or paste, is any non-metallic substance applied to one or both surfaces of two separate items that binds them together and resists their separation. The use of adhesives offers certain advantages over other binding techniques such as sewing, mechanical fastenings, or welding. These include the ability to bind different materials together, the more efficient distribution of stress across a joint, the cost-effectiveness of an easily mechanized process, and greater flexibility in design. Disadvantages of adhesive use include decreased stability at high temperatures, relative weakness in bonding large objects with a small bonding surface area, and greater difficulty in separating objects during testing. Adhesives are typically organized by the method of adhesion followed by ''reactive'' or ''non-reactive'', a term which refers to whether the adhesive chemically reacts in order to harden. Alternatively, they can be organized eithe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
