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Stigmastane
Stigmastane or 24''R''-ethylcholestane is a tetracyclic triterpene, along with cholestane and ergostane, this sterane is used as a biomarker for early eukaryotes. File:5α-Stigmastane.svg, 5α-Stigmastane File:5β-Stigmastane.svg, 5β-Stigmastane See also * Stigmastanol (Stigmastan-3β-ol) * β-Sitosterol (Stigmast-5-en-3β-ol) * Stigmasterol Stigmasterol – a plant sterol (''phytosterol'') – is among the most abundant of plant sterols, having a major function to maintain the structure and physiology of cell membranes. In the European Union, it is a food additive listed with E numb ... (Stigmast-5,22-dien-3β-ol) References {{Reflist Triterpenes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Union Of Pure And Applied Chemistry
The International Union of Pure and Applied Chemistry (IUPAC ) is an international federation of National Adhering Organizations working for the advancement of the chemical sciences, especially by developing nomenclature and terminology. It is a member of the International Science Council (ISC). IUPAC is registered in Zürich, Switzerland, and the administrative office, known as the "IUPAC Secretariat", is in Research Triangle Park, North Carolina, United States. This administrative office is headed by IUPAC's executive director, currently Lynn Soby. IUPAC was established in 1919 as the successor of the International Congress of Applied Chemistry for the advancement of chemistry. Its members, the National Adhering Organizations, can be national chemistry societies, national academies of sciences, or other bodies representing chemists. There are fifty-four National Adhering Organizations and three Associate National Adhering Organizations. IUPAC's Inter-divisional Committee on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Society Of Chemistry
The Royal Society of Chemistry (RSC) is a learned society (professional association) in the United Kingdom with the goal of "advancing the chemistry, chemical sciences". It was formed in 1980 from the amalgamation of the Chemical Society, the Royal Institute of Chemistry, the Faraday Society, and the Society for Analytical Chemistry with a new Royal Charter and the dual role of learned society and professional body. At its inception, the Society had a combined membership of 34,000 in the UK and a further 8,000 abroad. The headquarters of the Society are at Burlington House, Piccadilly, London. It also has offices in Thomas Graham House in Cambridge (named after Thomas Graham (chemist), Thomas Graham, the first president of the Chemical Society) where ''RSC Publishing'' is based. The Society has offices in the United States, on the campuses of The University of Pennsylvania and Drexel University, at the University City Science Center in Philadelphia, Pennsylvania, in both Beijing a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triterpene
Triterpenes are a class of chemical compounds composed of three terpene units with the molecular formula C30H48; they may also be thought of as consisting of six isoprene units. Animals, plants and fungi all produce triterpenes, including squalene, the precursor to all steroids. Structures Triterpenes exist in a great variety of structures. Nearly 200 different skeletons have been identified. These skeletons may be broadly divided according to the number of rings present. In general pentacyclic structures (5 rings) tend to dominate. Squalene is biosynthesized through the head-to-head condensation of two farnesyl pyrophosphate units. This coupling converts a pair of C15 components into a C30 product. Squalene serves as precursor for the formation of many triterpenoids, including bacterial hopanoids and eukaryotic sterols. Triterpenoids By definition triterpenoids are triterpenes that possess heteroatoms, usually oxygen. The terms ''triterpene'' and ''triterpenoid'' oft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cholestane
Cholestane is a saturated tetracyclic triterpene. This 27-carbon biomarker is produced by diagenesis of cholesterol and is one of the most abundant biomarkers in the rock record. Presence of cholestane, its derivatives and related chemical compounds in environmental samples is commonly interpreted as an indicator of animal life and/or traces of O2, as animals are known for exclusively producing cholesterol, and thus has been used to draw evolutionary relationships between ancient organisms of unknown phylogenetic origin and modern metazoan taxa. Cholesterol is made in low abundance by other organisms (e.g., rhodophytes, land plants), but because these other organisms produce a variety of sterols it cannot be used as a conclusive indicator of any one taxon. It is often found in analysis of organic compounds in petroleum. Background Cholestane is a saturated C-27 animal biomarker often found in petroleum deposits. It is a diagenetic product of cholesterol, which is an organic molec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ergostane
Ergostane is a tetracyclic triterpene, also known as 24''S''-methylcholestane. The compound itself has no known uses; however various functionalized analogues are produced by plants and animals. The most important of these are the heavily derivatised withanolides. However simpler forms do exist, such as the sterane campestane (24''R''-methylcholestane). Along with cholestane and stigmastane, this sterane is used as a biomarker for early eukaryotes. See also * Cholane * Cholestane * Lanostane Lanostane or 4,4,14α-trimethylcholestane is a chemical compound with formula . It is a polycyclic hydrocarbon, specifically a triterpene. It is an isomer of cucurbitane. The name is applied to two stereoisomers, distinguished by the prefixes 5Π... References {{Reflist Triterpenes Biomarkers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sterane
Sterane (cyclopentanoperhydrophenanthrenes) compounds are a class of tetracyclic compounds derived from steroids or sterols via diagenetic and catagenetic degradation and saturation. Steranes have an androstane skeleton with a side chain at carbon C-17. The sterane structure constitutes the core of all sterols. Steranes are sometimes used as biomarkers for the presence of eukaryotic cells. Steranes may be rearranged to diasteranes during diagenesis (C-27 to C-30, rearrangement at C-18 and C-19, no R at C-24). Oils from clastic source rocks tend to be rich in diasteranes. Cholesterol and its derivatives (such as progesterone, aldosterone, cortisol, and testosterone), are common examples of compounds with the cyclopentanoperhydrophenanthrene nucleus. See also * Cholestane Cholestane is a saturated tetracyclic triterpene. This 27-carbon biomarker is produced by diagenesis of cholesterol and is one of the most abundant biomarkers in the rock record. Presence of cholestane, its d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biomarker
In biomedical contexts, a biomarker, or biological marker, is a measurable indicator of some biological state or condition. Biomarkers are often measured and evaluated using blood, urine, or soft tissues to examine normal biological processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention. as cited in Biomarkers are used in many scientific fields. Medicine Biomarkers used in the medical field, are a part of a relatively new clinical toolset categorized by their clinical applications. The three main classes are molecular biomarkers, cellular biomarkers or imaging biomarkers. All three types of biomarkers have a clinical role in narrowing or guiding treatment decisions and follow a sub-categorization of being either predictive, prognostic, or diagnostic. Predictive Predictive molecular, cellular, or imaging biomarkers that pass validation can serve as a method of predicting clinical outcomes. Predictive biomarkers are used to help optimize id ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stigmastanol
Stigmastanol (sitostanol) is a phytosterol found in a variety of plant sources. Similar to sterol esters and stanol esters, stigmastanol inhibits the absorption of cholesterol from the diet. Animal studies suggest that it also inhibits biosynthesis of cholesterol in the liver. Stigmastanol is the product of the reduction of β-sitosterol and the hydrogenation of stigmasterol. See also * Stigmasterol Stigmasterol – a plant sterol (''phytosterol'') – is among the most abundant of plant sterols, having a major function to maintain the structure and physiology of cell membranes. In the European Union, it is a food additive listed with E numb ..., a closely related sterol References Phytosterols {{steroid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
β-Sitosterol
β-sitosterol (beta-sitosterol) is one of several phytosterols (plant sterols) with chemical structures similar to that of cholesterol. It is a white, waxy powder with a characteristic odor, and is one of the components of the food additive E499. Phytosterols are hydrophobic and soluble in alcohols. Natural occurrences and food β-sitosterol is widely distributed in the plant kingdom. It is found in vegetable oil, nuts, avocados, and derived prepared foods such as salad dressings. Human research β-sitosterol is being studied for its potential to reduce benign prostatic hyperplasia (BPH) and blood cholesterol levels. Genetic disorder While plant sterols are usually beneficial, there is a rare autosomal recessive genetic disorder phytosterolemia which causes over-absorption of phytosterols. Precursor of anabolic steroid boldenone Being a steroid, β-sitosterol is a precursor of anabolic steroid boldenone. Boldenone undecylenate is commonly used in veterinary medicine to induce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stigmasterol
Stigmasterol – a plant sterol (''phytosterol'') – is among the most abundant of plant sterols, having a major function to maintain the structure and physiology of cell membranes. In the European Union, it is a food additive listed with E number E499, and may be used in food manufacturing to increase the phytosterol content, potentially lowering the levels of LDL cholesterol. Discovery Once called ''Wulzen factor'' in the mid-20th century, stigmasterol was discovered by the University of California physiologist Rosalind Wulzen (born 1886). Natural occurrences Stigmasterol is an unsaturated phytosterol occurring in the plant fats or oils of numerous plants, such as soybean, calabar bean, and rape seed, and in herbs used in herbalism practices, including the Chinese herbs ''Ophiopogon japonicus'' (Mai men dong), in ''Mirabilis jalapa''. Stigmasterol is a constituent of various vegetables, legumes, nuts, seeds, and unpasteurized milk. Pasteurization will inactivate stig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
