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Cyclopropane Fatty Acid
Cyclopropane fatty acids (CPA) are a subgroup of fatty acids that contain a cyclopropane group. Although they are usually rare, the seed oil from lychee contains nearly 40% CPAs in the form of triglycerides. Biosynthesis CPAs are derived from unsaturated fatty acids by cyclopropanation. The methylene donor is a methyl group on S-adenosylmethionine (SAM). The conversion is catalyzed by cyclopropane-fatty-acyl-phospholipid synthase. The mechanism is proposed to involve transfer of a CH3+ group from SAM to the alkene, followed by deprotonation of the newly attached methyl group and ring closure. Cyclopropene fatty acids Cycloprop''e''ne fatty acids are even rarer than CPAs. The best-known examples are malvalic acid and sterculic acid. Sterculic acid as its triglyceride is present in sterculia oils and at low levels in kapok seed oil (~12%), cottonseed oil (~1%), and in the seeds of the tree ''Sterculia foetida'' (~65-78%). These acids are highly reactive but the cyclopropen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycobacterium Mycolic Acids
''Mycobacterium'' is a genus of over 190 species in the phylum Actinomycetota, assigned its own family, Mycobacteriaceae. This genus includes pathogens known to cause serious diseases in mammals, including tuberculosis (''Mycobacterium tuberculosis, M. tuberculosis'') and leprosy (''Mycobacterium leprae, M. leprae'') in humans. The Greek language, Greek prefix ''myco-'' means 'fungus', alluding to this genus' Mold (fungus), mold-like colony surfaces. Since this genus has Cell wall, cell walls with Gram-positive bacteria, Gram-positive and Gram-negative bacteria, Gram-negative features, Acid-fastness, acid-fast staining is used to emphasize their resistance to acids, compared to other cell types. Metabolism and Morphology Mycobacteria are aerobic organism, aerobic with 0.2-0.6 µm wide and 1.0-10 µm long Bacillus (shape), rod shapes. They are generally Non-motile bacteria, non-motile, except for the species ''Mycobacterium marinum'', which has been shown to be motile within macr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sterculic Acid
Sterculic acid is a cyclopropene fatty acid. It is found in various plants of the genus ''Sterculia'', including being the main component of ''Sterculia foetida'' seed oil. Biosynthesis The biosynthesis of sterculic acid begins with the cyclopropanation of the alkene of phospholipid-bound oleic acid, an 18-carbon ''Cis–trans isomerism, cis''-monounsaturated fatty acid. This transformation involves two mechanistic steps: electrophilic methylation with S-Adenosyl methionine, ''S''-adenosyl methionine to give a carbocationic reactive intermediate, followed by cyclization via loss of Hydron (chemistry), H+ mediated by a cyclopropane-fatty-acyl-phospholipid synthase enzyme. The product, dihydrosterculic acid, is converted to sterculic acid by dehydrogenation of the ''cis''-disubstituted cyclopropane to cyclopropene. An additional step of alpha oxidation, α oxidation removes one carbon from the carboxy chain to form the 17-carbon-chain structure of malvalic acid. References F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Co-carcinogen
A co-carcinogen is a chemical that promotes the effects of a carcinogen in the production of cancer. Usually, the term is used to refer to chemicals that are not carcinogenic on their own, such that an equivalent amount of the chemical is insufficient to initiate carcinogenesis. A chemical can be co-carcinogenic with other chemicals or with nonchemical carcinogens, such as UV radiation. For example, sodium arsenite can be administered to mice at a low enough concentration that it does not cause tumors on its own, but it increases the rate of formation and size of tumors formed after UV exposure. A chemical may act as a co-carcinogen even if it does not cause direct DNA damage such as mutation, as long as it can affect a cancer-related pathway. An example of this category includes chemicals within the phorbol ester family, which mimic a native signalling molecule. This ester is not mutagenic, but can increase the rate of cancer by promoting cell growth, a traditional hallmar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carcinogen
A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive substances are considered carcinogens, but their carcinogenic activity is attributed to the radiation, for example gamma rays and alpha particles, which they emit. Common examples of non-radioactive carcinogens are inhaled asbestos, certain dioxins, and tobacco smoke. Although the public generally associates carcinogenicity with synthetic chemicals, it is equally likely to arise from both natural and synthetic substances. Carcinogens are not necessarily immediately toxic; thus, their effect can be insidious. Carcinogens, as mentioned, are agents in the environment capable of contributing to cancer growth. Carcinogens can be categorized into two different types: activation-dependent and activation-independent, and each nature impacts their level ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oleic Acid
Oleic acid is a fatty acid that occurs naturally in various animal and vegetable fats and oils. It is an odorless, colorless oil, although commercial samples may be yellowish. In chemical terms, oleic acid is classified as a monounsaturated omega-9 fatty acid, abbreviated with a lipid number of 18:1 ''cis''-9, and a main product of Δ9 desaturase. It has the formula CH3(CH2)7CH=CH(CH2)7COOH. The name derives from the Latin word ''oleum'', which means oil. It is the most common fatty acid in nature. The salts and esters of oleic acid are called oleates. Occurrence Fatty acids (or their salts) often do not occur as such in biological systems. Instead fatty acids such as oleic acid occur as their esters, commonly triglycerides, which are the greasy materials in many natural oils. Oleic acid is the most common monounsaturated fatty acid in nature. It is found in fats (triglycerides), the phospholipids that make membranes, cholesterol esters, and wax esters. Triglycerides of oleic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stearic Acid
Stearic acid ( , ) is a saturated fatty acid with an 18-carbon chain. The IUPAC name is octadecanoic acid. It is a waxy solid and its chemical formula is C17H35CO2H. Its name comes from the Greek word στέαρ "''stéar''", which means tallow. The salts and esters of stearic acid are called stearates. As its ester, stearic acid is one of the most common saturated fatty acids found in nature following palmitic acid.Gunstone, F. D., John L. Harwood, and Albert J. Dijkstra "The Lipid Handbook with Cd-Rom. 3rd ed. Boca Raton: CRC Press, 2007. , The triglyceride derived from three molecules of stearic acid is called stearin. Occurrence and production Stearic acid is more abundant in animal fat (up to 30%) than in vegetable fat (typically <5%). The important exceptions are the foods (34%) and [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stearoyl-CoA 9-desaturase
Stearoyl-CoA desaturase (Δ-9-desaturase) is an endoplasmic reticulum enzyme that catalyzes the rate-limiting step in the formation of monounsaturated fatty acids (MUFAs), specifically oleate and palmitoleate from stearoyl-CoA and palmitoyl-CoA. Oleate and palmitoleate are major components of membrane phospholipids, cholesterol esters and alkyl-diacylglycerol. In humans, the enzyme is encoded by the SCD gene. Stearoyl-CoA desaturase-1 is a key enzyme in fatty acid metabolism. It is responsible for forming a double bond in Stearoyl-CoA. This is how the monounsaturated fatty acid oleic acid is produced from the saturated fatty acid stearic acid. A series of redox reactions, during which two electrons flow from NADH to flavoprotein cytochrome b5, then to the electron acceptor cytochrome b5 as well as molecular oxygen introduces a single double bond within a row of methylene fatty acyl-CoA substrates. The complexed enzyme adds a single double bond between the C9 and C10 of lon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sterculia Foetida
''Sterculia foetida'' is a soft wooded tree that can grow up to tall.Sterculia Foetida" - Meet the Plants - National Tropical Botanical Garden Plant Database. Web. 08 Dec. 2013. Common names for the plant are the bastard poon tree, java olive tree, hazel sterculia, wild almond tree, and skunk tree. Description The branches of ''Sterculia foetida'' are arranged in s; they spread horizontally. The tree's bark is smooth and gray. The are placed at the end of branchlets; they have[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cottonseed Oil
Cottonseed oil is cooking oil from the seeds of cotton plants of various species, mainly ''Gossypium hirsutum'' and ''Gossypium herbaceum'', that are grown for cotton fiber, animal feed, and oil. Cotton seed has a similar structure to other oilseeds such as sunflower seed, having an oil-bearing kernel surrounded by a hard outer hull; in processing, the oil is extracted from the kernel. Cottonseed oil is used for salad oil, mayonnaise, salad dressing, and similar products because of its flavor stability. Composition Its fatty acid profile generally consists of 70% unsaturated fatty acids (18% monounsaturated, and 52% polyunsaturated), 26% saturated fatty acids. When it is fully hydrogenated, its profile is 94% saturated fat and 2% unsaturated fatty acids (1.5% monounsaturated, and 0.5% polyunsaturated). According to the cottonseed oil industry, cottonseed oil does not need to be hydrogenated as much as other polyunsaturated oils to achieve similar results. Gossypol is a toxic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kapok Tree
Kapok tree can refer to several plants Malvales with one exception with seeds that grow long hairs: *''Bombax ceiba'', an Asian tree with red flowers *''Calotropis procera'' (Asterid), a shrub with white and purple flowers, native to Asia and North Africa, but a weed in other places *''Ceiba pentandra'', a tree of the tropical Americas with white flowers, cultivated particularly in south-east Asia for its seed fibre *Two trees with yellow flowers native to northern Australia and Papua New Guinea **''Cochlospermum gillivraei ''Cochlospermum gillivraei'' is a tree in the family Bixaceae, with the common name kapok. It is native to Northern Australia. References gillivraei {{rosid-tree-stub ...'' **'' Cochlospermum fraseri'' {{Plant common name ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malvalic Acid
Malvalic acid is a cyclopropene fatty acid found in baobab seed oil and cottonseed oil. The cyclopropene ring is thought to be one of the causes of abnormalities that develop in animals that ingest cottonseed oil. Refining processes, such as hydrogenation, can remove or destroy malvalic acid. Biosynthesis The biosynthesis of malvalic acid starts with oleic acid, an 18-carbon monounsaturated fatty acid, leading to sterculic acid. An α-oxidation reaction removes one carbon from the chain to form the 17-carbon-chain structure of malvalic acid. History Wilson et al. demonstrated the co-occurrence of malvalic acid and the corresponding cyclopropane acids in several types of seeds. He suggested that methylene addition to oleic acid gave rise to dihydrosterculic acid, which was desaturated to sterculic acid, and that 8-heptadecenoic acid was similarly the precursor of dihydromalvalic acid and malvalic acid. Smith and Bu'Lock showed that in ''Hibiscus ''Hibiscus'' is a genus of flo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fatty Acids
In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an 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 dietary sources of fuel for animals and important structural components for 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 "oily acid"). Types of fatty acids Fatty acids are classified in many ways: by length, by saturation vs unsatura ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
