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Cholesterol

C27H46O (386.3548466)

Cholesterol is a sterol (a combination steroid and alcohol) and a lipid found in the cell membranes of all body tissues and transported in the blood plasma of all animals. The name originates from the Greek chole- (bile) and stereos (solid), and the chemical suffix -ol for an alcohol. This is because researchers first identified cholesterol in solid form in gallstones in 1784. In the body, cholesterol can exist in either the free form or as an ester with a single fatty acid (of 10-20 carbons in length) covalently attached to the hydroxyl group at position 3 of the cholesterol ring. Due to the mechanism of synthesis, plasma cholesterol esters tend to contain relatively high proportions of polyunsaturated fatty acids. Most of the cholesterol consumed as a dietary lipid exists as cholesterol esters. Cholesterol esters have a lower solubility in water than cholesterol and are more hydrophobic. They are hydrolyzed by the pancreatic enzyme cholesterol esterase to produce cholesterol and free fatty acids. Cholesterol has vital structural roles in membranes and in lipid metabolism in general. It is a biosynthetic precursor of bile acids, vitamin D, and steroid hormones (glucocorticoids, estrogens, progesterones, androgens and aldosterone). In addition, it contributes to the development and functioning of the central nervous system, and it has major functions in signal transduction and sperm development. Cholesterol is a ubiquitous component of all animal tissues where much of it is located in the membranes, although it is not evenly distributed. The highest proportion of unesterified cholesterol is in the plasma membrane (roughly 30-50\\\\% of the lipid in the membrane or 60-80\\\\% of the cholesterol in the cell), while mitochondria and the endoplasmic reticulum have very low cholesterol contents. Cholesterol is also enriched in early and recycling endosomes, but not in late endosomes. The brain contains more cholesterol than any other organ where it comprises roughly a quarter of the total free cholesterol in the human body. Of all the organic constituents of blood, only glucose is present in a higher molar concentration than cholesterol. Cholesterol esters appear to be the preferred form for transport in plasma and as a biologically inert storage (de-toxified) form. They do not contribute to membranes but are packed into intracellular lipid particles. Cholesterol molecules (i.e. cholesterol esters) are transported throughout the body via lipoprotein particles. The largest lipoproteins, which primarily transport fats from the intestinal mucosa to the liver, are called chylomicrons. They carry mostly triglyceride fats and cholesterol that are from food, especially internal cholesterol secreted by the liver into the bile. In the liver, chylomicron particles give up triglycerides and some cholesterol. They are then converted into low-density lipoprotein (LDL) particles, which carry triglycerides and cholesterol on to other body cells. In healthy individuals, the LDL particles are large and relatively few in number. In contrast, large numbers of small LDL particles are strongly associated with promoting atheromatous disease within the arteries. (Lack of information on LDL particle number and size is one of the major problems of conventional lipid tests.). In conditions with elevated concentrations of oxidized LDL particles, especially small LDL particles, cholesterol promotes atheroma plaque deposits in the walls of arteries, a condition known as atherosclerosis, which is a major contributor to coronary heart disease and other forms of cardiovascular disease. There is a worldwide trend to believe that lower total cholesterol levels tend to correlate with lower atherosclerosis event rates (though some studies refute this idea). As a result, cholesterol has become a very large focus for the scientific community trying to determine the proper amount of cholesterol needed in a healthy diet. However, the primary association of atherosclerosis with c... Constituent either free or as esters, of fish liver oils, lard, dairy fats, egg yolk and bran Cholesterol is the major sterol in mammals. It is making up 20-25\\% of structural component of the plasma membrane. Plasma membranes are highly permeable to water but relatively impermeable to ions and protons. Cholesterol plays an important role in determining the fluidity and permeability characteristics of the membrane as well as the function of both the transporters and signaling proteins[1][2]. Cholesterol is also an endogenous estrogen-related receptor α (ERRα) agonist[3]. Cholesterol is the major sterol in mammals. It is making up 20-25\% of structural component of the plasma membrane. Plasma membranes are highly permeable to water but relatively impermeable to ions and protons. Cholesterol plays an important role in determining the fluidity and permeability characteristics of the membrane as well as the function of both the transporters and signaling proteins[1][2]. Cholesterol is also an endogenous estrogen-related receptor α (ERRα) agonist[3].

Lanosterol

C30H50O (426.386145)

Lanosterol, also known as lanosterin, belongs to the class of organic compounds known as triterpenoids. These are terpene molecules containing six isoprene units. Thus, lanosterol is considered to be a sterol lipid molecule. Lanosterol is a very hydrophobic molecule, practically insoluble (in water), and relatively neutral. Lanosterol is biochemically synthesized starting from acetyl-CoA by the HMG-CoA reductase pathway. The critical step is the enzymatic conversion of the acyclic terpene squalene to the polycylic lanosterol via 2,3-squalene oxide. Constituent of wool fat used e.g. as chewing-gum softenerand is) also from yeast COVID info from COVID-19 Disease Map Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS

7-Dehydrocholesterol

C27H44O (384.3391974)

7-Dehydrocholesterol (7-DHC), also known as provitamin D3 or 5,7-cholestadien-3-b-ol, belongs to the class of organic compounds known as cholesterols and derivatives. Cholesterols and derivatives are compounds containing a 3-hydroxylated cholestane core. Thus, 7-dehydrocholesterol is also classified as a sterol. 7-Dehydrocholesterol is known as a zoosterol, meaning that it is a sterol isolated from animals (to distinguish those sterols isolated from plants which are called phytosterols). 7-DHC functions in the serum as a cholesterol precursor and is photochemically converted to vitamin D3 in the skin. Therefore 7-DHC functions as provitamin-D3. The presence of 7-DHC in human skin enables humans and other mammals to manufacture vitamin D3 (cholecalciferol) from ultraviolet rays in the sun light, via an intermediate isomer pre-vitamin D3. 7-DHC absorbs UV light most effectively at wavelengths between 290 and 320 nm and, thus, the production of vitamin D3 will occur primarily at those wavelengths (PMID: 9625080). The two most important factors that govern the generation of pre-vitamin D3 are the quantity (intensity) and quality (appropriate wavelength) of the UVB irradiation reaching the 7-dehydrocholesterol deep in the stratum basale and stratum spinosum (PMID: 9625080). 7-DHC is also found in the milk of several mammalian species, including cows (PMID: 10999630; PMID: 225459). It was discovered by Nobel-laureate organic chemist Adolf Windaus. 7-DHC can be produced by animals and plants via different pathways (PMID: 23717318). It is not produced by fungi in significant amounts. 7-DHC is made by some algae and can also be produced by some bacteria. 7-Dehydrocholesterol is a zoosterol (a sterol produced by animals rather than plants). It is a provitamin-D. The presence of this compound in skin enables humans to manufacture vitamin D3 from ultra-violet rays in the sun light, via an intermediate isomer provitamin D3. It is also found in breast milk. [HMDB] D018977 - Micronutrients > D014815 - Vitamins > D000072664 - Provitamins 7-Dehydrocholesterol is biosynthetic precursor of cholesterol and vitamin D3. 7-Dehydrocholesterol is biosynthetic precursor of cholesterol and vitamin D3.

Lathosterol

C27H46O (386.3548466)

Lathosterol is a a sterol (a combination steroid and alcohol) and a lipid found in the cell membranes of all body tissues, and transported in the blood plasma of all animals. It is used as an indicator of whole-body cholesterol synthesis (PMID 14511438). Plasma lathosterol levels are significantly elevated in patients with bile acid malabsorption (PMID: 8777839). Lathosterol oxidase (EC 1.14.21.6) is an enzyme that catalyzes the chemical reaction 5alpha-cholest-7-en-3beta-ol + NAD(P)H + H+ + O2 cholesta-5,7-dien-3beta-ol + NAD(P)+ + 2 H2O [HMDB] Lathosterol is a a sterol (a combination steroid and alcohol) and a lipid found in the cell membranes of all body tissues, and transported in the blood plasma of all animals. It is used as an indicator of whole-body cholesterol synthesis (PMID 14511438). Plasma lathosterol levels are significantly elevated in patients with bile acid malabsorption (PMID:8777839). Lathosterol oxidase (EC 1.14.21.6) is an enzyme that catalyzes the chemical reaction 5alpha-cholest-7-en-3beta-ol + NAD(P)H + H+ + O2 cholesta-5,7-dien-3beta-ol + NAD(P)+ + 2 H2O. Lathosterol is a cholesterol-like molecule. Serum Lathosterol concentration is an indicator of whole-body cholesterol synthesis. Lathosterol is a cholesterol-like molecule. Serum Lathosterol concentration is an indicator of whole-body cholesterol synthesis.

Desmosterol

C27H44O (384.3391974)

Desmosterol is an intermediate in the synthesis of cholesterol. Desmosterolosis is a rare autosomal recessive inborn errors of cholesterol synthesis that is caused by defective activity of desmosterol reductase which results in an accumulation of demosterol (DHCR24, EC 1.3.1.72), combines a severe osteosclerotic skeletal dysplasia and includes 2-3 toe syndactyly with Smith-Lemli-Opitz syndrome (SLOS; the biochemical block in SLOS results in decreased cholesterol levels and increased 7-dehydrocholesterol levels). Desmosterolosis is caused by mutation of the 24-dehydrocholesterol reductase gene (DHCR24). Many of the malformations in SLOS and desmosterolosis are consistent with impaired hedgehog function. The hedgehog proteins include Sonic hedgehog (SHH), which plays a major role in midline patterning and limb development. Desmosterolosis, caused by defective activity of desmosterol reductase, combines a severe osteosclerotic skeletal dysplasia. 7-dehydrocholesterol reductase (DHCR7, EC 1.3.1.21) reduces the C7-C8 double bond in the sterol B ring to form cholesterol or desmosterol depending upon the precursor. Desmosterol can be converted to cholesterol by DHCR24. Therefore, SLOS and Desmosterolosis patients invariably have elevated levels of cholesterol precursors 7-dehydrocholesterol (and its spontaneous isomer 8-dehydrocholesterol) and absent desmosterol. (PMID: 14631207, 16207203). Desmosterol is found in many foods, some of which are fig, sago palm, mexican groundcherry, and pepper (c. frutescens). Desmosterol is an intermediate in the synthesis of cholesterol. Desmosterolosis is a rare autosomal recessive inborn errors of cholesterol synthesis that is caused by defective activity of desmosterol reductase which results in an accumulation of demosterol (DHCR24, EC 1.3.1.72), combines a severe osteosclerotic skeletal dysplasia and includes 2-3 toe syndactyly with Smith-Lemli-Opitz syndrome (SLOS; the biochemical block in SLOS results in decreased cholesterol levels and increased 7-dehydrocholesterol levels). Desmosterolosis is caused by mutation of the 24-dehydrocholesterol reductase gene (DHCR24). Many of the malformations in SLOS and desmosterolosis are consistent with impaired hedgehog function. The hedgehog proteins include Sonic hedgehog (SHH), which plays a major role in midline patterning and limb development. Desmosterolosis, caused by defective activity of desmosterol reductase, combines a severe osteosclerotic skeletal dysplasia. 7-dehydrocholesterol reductase (DHCR7, EC 1.3.1.21) reduces the C7-C8 double bond in the sterol B ring to form cholesterol or desmosterol depending upon the precursor. Desmosterol can be converted to cholesterol by DHCR24. Therefore, SLOS and Desmosterolosis patients invariably have elevated levels of cholesterol precursors 7-dehydrocholesterol (and its spontaneous isomer 8-dehydrocholesterol) and absent desmosterol. (PMID: 14631207, 16207203). Desmosterol is a molecule similar to cholesterol. Desmosterol is the immediate precursor of cholesterol in the Bloch pathway of cholesterol biosynthesis. Desmosterol, as an endogenous metabolite, used to study cholesterol metabolism[1]. Desmosterol is a molecule similar to cholesterol. Desmosterol is the immediate precursor of cholesterol in the Bloch pathway of cholesterol biosynthesis. Desmosterol, as an endogenous metabolite, used to study cholesterol metabolism[1].

5alpha-Cholest-8-en-3beta-ol

C27H46O (386.3548466)

5a-Cholest-8-en-3b-ol is a normal human metabolite and an intermediate of cholesterol synthesis. The concentrations of zymostenol are higher, both in serum and bile of patients with cerebrotendinous xanthomatosis, compared to controls or in patients with cerebrotendinous xanthomatosis treated with chenodeoxycholic acid. Kidney transplant recipients had lower serum zymostenol when compared to controls. During consumption of plant stanol ester spread by hypercholesterolemic children, plant sterols in the plasma decrease and cholesterol precursor sterols such as zymostenol increase. (PMID: 15736111, 16709621, 16477216, 12756385) [HMDB]. 5a-Cholest-8-en-3b-ol is found in many foods, some of which are chinese water chestnut, garden tomato, calabash, and cassava. 5alpha-Cholest-8-en-3beta-ol, also known as zymostenol, is a normal human metabolite and an intermediate of cholesterol synthesis. The concentrations of zymostenol are higher, both in the serum and bile of patients with cerebrotendinous xanthomatosis, compared to controls or in patients with cerebrotendinous xanthomatosis treated with chenodeoxycholic acid. Kidney transplant recipients had lower serum zymostenol when compared to controls. During consumption of plant stanol ester spread by hypercholesterolemic children, plant sterols in the plasma decreased and cholesterol precursor sterols such as zymostenol increased (PMID: 15736111, 16709621, 16477216, 12756385).

7-Dehydrodesmosterol

C27H42O (382.3235482)

7-dehydrodesmosterol, also known as cholesta-5,7,24-trien-3beta-ol or 24-dehydroprovitamin d3, belongs to cholesterols and derivatives class of compounds. Those are compounds containing a 3-hydroxylated cholestane core. Thus, 7-dehydrodesmosterol is considered to be a sterol lipid molecule. 7-dehydrodesmosterol is practically insoluble (in water) and an extremely weak acidic compound (based on its pKa). 7-dehydrodesmosterol can be found in a number of food items such as nectarine, orange bell pepper, cinnamon, and carrot, which makes 7-dehydrodesmosterol a potential biomarker for the consumption of these food products. In humans, 7-dehydrodesmosterol is involved in several metabolic pathways, some of which include atorvastatin action pathway, simvastatin action pathway, pamidronate action pathway, and steroid biosynthesis. 7-dehydrodesmosterol is also involved in several metabolic disorders, some of which include mevalonic aciduria, wolman disease, chondrodysplasia punctata II, X linked dominant (CDPX2), and hyper-igd syndrome. 7-Dehydrodesmosterol is a sterol intermediate in the biosynthesis of steroids. 7-Dehydrodesmosterol is a substrate of the enzyme 24-dehydrocholesterol reductase (EC:1.3.1.72), an important enzyme in the biosynthesis of Cholesterol. Cholesterol is synthesized from either Lathosterol, 7-Dehydrocholesterol, Desmosterol or Cholestenol by the enzyme 3beta-hydroxysterol delta7 reductase (EC 1.3.1.21, Dhcr7). The Smith-Lemli-Opitz syndrome (SLOS, OMIM 270400) is caused by a genetic defect in cholesterol biosynthesis; mutations in the enzyme 3beta-hydroxysterol delta7 reductase lead to a failure of cholesterol synthesis, with an accumulation of precursor sterols, such as 7-Dehydrodesmosterol. SLOS results in craniofacial, limb as well as major organ defects, including the brain. In individuals with this syndrome, mental retardation, as well as other CNS dysfunction, is almost 100\\% prevalent. (PMID: 15862627, 17197219).

Zymosterol intermediate 2

C27H44O (384.3391974)

Zymosterol, also known as 5alpha-cholesta-8,24-dien-3beta-ol or delta8,24-cholestadien-3beta-ol, belongs to cholesterols and derivatives class of compounds. Those are compounds containing a 3-hydroxylated cholestane core. Thus, zymosterol is considered to be a sterol lipid molecule. Zymosterol is practically insoluble (in water) and an extremely weak acidic compound (based on its pKa). Zymosterol can be synthesized from 5alpha-cholestane. Zymosterol is also a parent compound for other transformation products, including but not limited to, 4beta-methylzymosterol-4alpha-carboxylic acid, 3-dehydro-4-methylzymosterol, and zymosterol intermediate 1b. Zymosterol can be found in a number of food items such as squashberry, hard wheat, salmonberry, and loquat, which makes zymosterol a potential biomarker for the consumption of these food products. Zymosterol exists in all eukaryotes, ranging from yeast to humans. In humans, zymosterol is involved in several metabolic pathways, some of which include zoledronate action pathway, alendronate action pathway, pravastatin action pathway, and atorvastatin action pathway. Zymosterol is also involved in several metabolic disorders, some of which include cholesteryl ester storage disease, lysosomal acid lipase deficiency (wolman disease), smith-lemli-opitz syndrome (SLOS), and chondrodysplasia punctata II, X linked dominant (CDPX2). Zymosterol is an intermediate in cholesterol biosynthesis. Disregarding some intermediate compounds (e.g. 4-4-dimethylzymosterol) lanosterol can be considered a precursor of zymosterol in the cholesterol synthesis pathway. The conversion of zymosterol into cholesterol happens in the endoplasmic reticulum. Zymosterol accumulates quickly in the plasma membrane coming from the cytosol. The movement of zymosterol across the cytosol is more than twice as fast as the movement of cholesterol itself . Zymosterol is the precursor of cholesterol and is found in the plasma membrane. zymosterol circulates within the cells. The structural features of zymosterol provided optimal substrate acceptability. In human fibroblasts, zymosterol is converted to cholesterol solely in the rough ER. Little or no zymosterol or cholesterol accumulates in the rough ER in vivo. Newly synthesized zymosterol moves to the plasma membrane without a detectable lag and with a half-time of 9 min, about twice as fast as cholesterol. The pool of radiolabeled zymosterol in the plasma membrane turns over rapidly, faster than does intracellular cholesterol. Thus, plasma membrane zymosterol is not stagnant. [3H]Zymosterol pulsed into intact cells is initially found in the plasma membrane. (PMID: 1939176). COVID info from COVID-19 Disease Map Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS

4,4-Dimethylcholesta-8,14,24-trienol

C29H46O (410.3548466)

4,4-Dimethylcholesta-8,14,24-trienol is a product of the enzyme delta14-sterol reductase [EC 1.3.1.70] (KEGG). It is involved in the biosynthesis of steroids and is involved in the conversion of lanosterol to zymosterol. In particular, lanosterol 14-alpha-demethylase, catalyzes the C-14 demethylation of lanosterol to form 4,4-Dimethylcholesta-8,14,24-trienol in the ergosterol biosynthesis pathway. It is thought to be a meiosis activating sterol. [HMDB] 4,4-Dimethylcholesta-8,14,24-trienol is a product of the enzyme delta14-sterol reductase [EC 1.3.1.70] (KEGG). It is involved in the biosynthesis of steroids and is involved in the conversion of lanosterol to zymosterol. In particular, lanosterol 14-alpha-demethylase, catalyzes the C-14 demethylation of lanosterol to form 4,4-Dimethylcholesta-8,14,24-trienol in the ergosterol biosynthesis pathway. It is thought to be a meiosis activating sterol.

ST 29:1;O

C29H50O (414.386145)

A cholestanoid that is 5alpha-cholesta-8-en-3beta-ol bearing two additional methyl substituents at position 4.

5alpha-Cholesta-7,24-dien-3beta-ol

C27H44O (384.3391974)

5alpha-Cholesta-7,24-dien-3beta-ol belongs to the class of organic compounds known as cholesterols and derivatives. Cholesterols and derivatives are compounds containing a 3-hydroxylated cholestane core. Thus, 5alpha-cholesta-7,24-dien-3beta-ol is considered to be a sterol lipid molecule. 5alpha-Cholesta-7,24-dien-3beta-ol is involved in the biosynthesis of steroids. 5alpha-Cholesta-7,24-dien-3beta-ol is reversibly converted into 5alpha-cholest-7-en-3beta-ol by delta24-sterol reductase (EC 1.3.1.72). 5alpha-Cholesta-7,24-dien-3beta-ol is also converted into zymosterol by cholestenol delta-isomerase (EC 5.3.3.5). 5alpha-Cholesta-7,24-dien-3beta-ol is also converted into 7-Dehydrodesmosterol. 5alpha-Cholesta-7,24-dien-3beta-ol is a substrate for 3-beta-hydroxysteroid-delta(8),delta(7)-isomerase. 5alpha-Cholesta-7,24-dien-3beta-ol is involved in the biosynthesis of steroids. 5alpha-Cholesta-7,24-dien-3beta-ol is reversibly converted to 5alpha-Cholest-7-en-3beta-ol by delta24-sterol reductase [EC:1.3.1.72]. 5alpha-Cholesta-7,24-dien-3beta-ol is also converted to zymosterol by cholestenol delta-isomerase [EC:5.3.3.5]. 5alpha-Cholesta-7,24-dien-3beta-ol is also converted to 7-Dehydrodesmosterol. 5a-Cholesta-7,24-dien-3b-ol is a substrate for 3-beta-hydroxysteroid-delta(8),delta(7)-isomerase. [HMDB]

8-Dehydrocholesterol

C27H44O (384.3391974)

8-Dehydrocholesterol (8-DHC) elevated concentration is one of the diagnostic biochemical hallmarks of classical Smith-Lemli-Opitz syndrome (SLOS). Plasma 8-DHC could be only marginally elevated. (PMID: 16435228). Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive condition caused by a defect in cholesterol synthesis (caused by a deficit of 3beta-hydroxysterol-Delta7 reductase). Affected children often have malformations and mental retardation. Autistic behaviors also are evident. In children, the baseline cholesterol, 8-DHC levels, and cholesterol levels following supplementation does not correlate with the presence or severity of autistic symptoms. (PMID: 16761297). Accumulation of 8-dehydrocholesterol in Amniotic fluid is diagnostic for SLOS. (PMID 16231320). 8-Dehydrocholesterol (8-DHC) elevated concentration is one of the diagnostic biochemical hallmarks of classical Smith-Lemli-Opitz syndrome (SLOS) . Plasma 8-DHC could be only marginally elevated. (PMID: 16435228) 8-Dehydrocholesterol elevated concentration is one of the diagnostic biochemical hallmarks of classical Smith-Lemli-Opitz syndrome (SLOS).

14-Demethyllanosterol

C29H48O (412.37049579999996)

A 3beta-sterol formed formally by loss of a methyl group from the 14-position of lanosterol.

4,4-Dimethylcholesta-8(9),14-dien-3beta-ol

C29H48O (412.37049579999996)