Sterols

Cholesterol is the principal sterol of all animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.

Estrogen (American English) or oestrogen (Commonwealth English; see spelling differences) is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal activity: estrone (E1), estradiol (E2), and estriol (E3). Estradiol, an estrane, is the most potent and prevalent. Another estrogen called estetrol (E4) is produced only during pregnancy.

class=skin-invert-image|thumb|Gonan-3-ol, the simplest sterol

Ergosterol (ergosta-5,7,22-trien-3β-ol) is a mycosterol found in cell membranes of fungi and protozoa, serving many of the same functions that cholesterol serves in animal cells. Because many fungi and protozoa cannot survive without ergosterol, the enzymes that synthesize it have become important targets for drug discovery. In human nutrition, ergosterol is a provitamin form of vitamin D2; exposure to ultraviolet (UV) light causes a chemical reaction that produces vitamin D2.

Estrone (E1), also spelled oestrone, is a steroid, a weak estrogen, and a minor female sex hormone. It is one of three major endogenous estrogens, the others being estradiol and estriol. Estrone, as well as the other estrogens, are synthesized from cholesterol and secreted mainly from the gonads, though they can also be formed from adrenal androgens in adipose tissue. Relative to estradiol, both estrone and estriol have far weaker activity as estrogens. Estrone can be converted into estradiol, and serves mainly as a precursor or metabolic intermediate of estradiol. It is both a precursor and m

Pregnenolone (P5), or pregn-5-en-3β-ol-20-one, is an endogenous steroid and precursor/metabolic intermediate in the biosynthesis of most of the steroid hormones, including the progestogens, androgens, estrogens, glucocorticoids, and mineralocorticoids. In addition, pregnenolone is biologically active in its own right, acting as a neurosteroid.

Lanosterol is a tetracyclic triterpenoid and is the compound from which all animal and fungal steroids are derived. By contrast, plant steroids are produced via cycloartenol. In the eyes of vertebrates, lanosterol is a natural constituent, having a role in maintaining health of the lens. Lanosterol is the precursor to cholesterol.

Allopregnanolone is a naturally occurring neurosteroid which is made in the body from the hormone progesterone. As a medication, allopregnanolone was referred to as brexanolone, sold under the brand name Zulresso, and was used to treat postpartum depression. It was given by injection into a vein.

thumb|250px|right|The epidermal strata of the skin

Cycloartenol is an important triterpenoid often found in plants. It belongs to the sterol class of steroids. It is the starting point for the synthesis of almost all plant steroids, making them chemically distinct from the steroids of fungi and animals, which are, instead, produced from lanosterol.

Lumisterol is a compound that is part of the vitamin D family of steroid compounds. It is the (9β,10α) stereoisomer of ergosterol and was produced as a photochemical by-product in the preparation of vitamin D1, which was a mixture of vitamin D2 and lumisterol. Vitamin D2 can be formed from lumisterol by an electrocyclic ring opening and subsequent [[Sigmatropic reaction#.5B1.2C7.5D_Shifts|sigmatropic [1,7] hydride shift]].

Ganaxolone, sold under the brand name Ztalmy, is a medication used to treat seizures in people with cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder. Ganaxolone is a neuroactive steroid gamma-aminobutyric acid (GABA) A receptor positive modulator.

Lathosterol is a cholesterol-like molecule found small amounts in humans. The enzyme Δ7-sterol 5(6)-desaturase converts it to 7-dehydrocholesterol. It is accumulated in lathosterolosis.

Equilenin, also known as 6,8-didehydroestrone, as well as estra-1,3,5(10),6,8-pentaen-3-ol-17-one, is a naturally occurring steroidal estrogen obtained from the urine of pregnant mares. It is used as one of the components in conjugated estrogens (brand name Premarin). It was the first complex natural product to be fully synthesized, in work reported by 1940 by Bachmann and Wilds.

20-Hydroxyecdysone (ecdysterone or 20E) is a naturally occurring ecdysteroid hormone which controls the ecdysis (moulting) and metamorphosis of arthropods. It is therefore one of the most common moulting hormones in insects, crabs, etc. A phytoecdysteroid produced by and extracted from various plants, including Cyanotis vaga, Ajuga turkestanica and Rhaponticum carthamoides, it is thought to be a plant defense against herbivory that disrupts the reproduction of insect pests. In arthropods, 20-hydroxyecdysone acts through the ecdysone receptor. Although mammals (including humans) lack this recep

chemical compound

Adosterol is an iodine-containing sterol.

7-Dehydrositosterol is a sterol which serves as a precursor for sitocalciferol (vitamin D5).

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.

Equilin is a naturally occurring estrogen sex hormone found in horses as well as a medication. It is one of the estrogens present in the estrogen combination drug preparations known as conjugated estrogens (CEEs; e.g. Premarin) and esterified estrogens (EEs; e.g. Estratab, Menest). CEEs is the most commonly used form of estrogen medications in hormone replacement therapy (HRT) for menopausal symptoms in the United States. Estrone sulfate is the major estrogen in CEEs (about 50%) while equilin sulfate is the second major estrogen in the formulation, present as about 25% of the total.

Alfaxalone, also known as alphaxalone or alphaxolone and sold under the brand name Alfaxan and Faxone, is a neuroactive steroid and general anesthetic which is used currently in veterinary practice as an induction agent for anesthesia and as an injectable anesthetic. The most common side effect seen in current veterinary practice is respiratory depression when Alfaxan is administered concurrently with other sedative and anesthetic drugs; when premedications are not given, veterinary patients also become agitated and hypersensitive when waking up.

5-Dehydroepisterol is a sterol and an intermediate in steroid biosynthesis, particularly synthesis of brassinosteroids. It is formed from episterol through action of ERG3, the C-5 sterol desaturase in the yeast and is then converted into 24-methylenecholesterol by 7-dehydrocholesterol reductase.

Episterol is a sterol involved in the biosynthesis of steroids. Episterol is synthesized from 24-methylenelophenol. Episterol is converted to 5-dehydroepisterol by ERG3, the C-5 sterol desaturase in the yeast. Episterol is also known to be a precursor to ergosterol.

Panaxatriol is an organic compound that is an aglycone of ginsenosides, a group of steroid glycosides. It is a dammarane-type tetracyclic triterpene sapogenin found in ginseng (Panax ginseng) and in notoginseng (Panax pseudoginseng). It is formed by the dehydration of protopanaxatriol.

7α-Hydroxycholesterol is a precursor of bile acids, created by cholesterol 7α-hydroxylase (CYP7A1). Its formation is the rate-determining step in bile acid synthesis.

Hippuristanol is a small molecule found in the coral Isis hippuris which was discovered by Jerry Pelletier and others of McGill University in Montreal, Quebec, Canada. It appears to have anti-viral activity and may hold promise as a cancer therapy. Binds to and inhibits the eukaryotic translation initiation factor protein eIF4A.

Azacosterol (), or azacosterol hydrochloride () (brand name Ornitrol), also called 20,25-diazacholesterol, is a cholesterol-lowering drug (hypocholesteremic), which was marketed previously, but has since been discontinued. It is also an avian chemosterilant used to control pest pigeon populations via inducing sterility. The drug is a sterol and derivative of cholesterol in which two carbon atoms have been replaced with nitrogen atoms.

chemical compound

An oxysterol is a derivative of cholesterol obtained by oxidation involving enzymes and / or pro-oxidants. Such compounds play important roles in various biological processes such as cholesterol homeostasis, lipid metabolism (sphingolipids, fatty acids), apoptosis, autophagy, and prenylation of proteins; the mode of action of oxysterols in these effects is still poorly understood. Several oxysterols are associated with age-related diseases such as cardiovascular disease, eye disease (cataract, age-related macular degeneration), certain neurodegenerative diseases and cancers. Identifying thera

lipids in the blood, either free or bound to other molecules

Dinosterol (4α,23,24-trimethyl-5α-cholest-22E-en-3β-ol) is a 4α-methyl sterol that is produced by several genera of dinoflagellates and is rarely found in other classes of protists. The steroidal alkane, dinosterane, is the 'molecular fossil' of dinosterol, meaning that dinosterane has the same carbon skeleton as dinosterol, but lacks dinosterol's hydroxyl group and olefin functionality. As such, dinosterane is often used as a biomarker to identify the presence of dinoflagellates in sediments.

'22R-Hydroxycholesterol, or (3β)-cholest-5-ene-3,22-diol' is an endogenous, metabolic intermediate in the biosynthesis of the steroid hormones from cholesterol. Cholesterol ((3β)-cholest-5-en-3-ol) is hydroxylated by cholesterol side-chain cleavage enzyme (P450scc) to form 22R-hydroxycholesterol, which is subsequently hydroxylated again by P450scc to form 20α,22R-dihydroxycholesterol, and finally the bond between carbons 20 and 22 is cleaved by P450scc to form pregnenolone ((3β)-3-hydroxypregn-5-en-20-one), the precursor to the steroid hormones.

Avenasterol, or Δ-7-Avenasterol is a natural, stigmastane-type sterol.

Fucosterol is a sterol isolated from algae such as Ecklonia cava or Ecklonia stolonifera.

Fecosterol is a sterol made by certain fungi and lichens.

'20α,22R-Dihydroxycholesterol, or (3β)-cholest-5-ene-3,20,22-triol' is an endogenous, metabolic intermediate in the biosynthesis of the steroid hormones from cholesterol. Cholesterol ((3β)-cholest-5-en-3-ol) is hydroxylated by cholesterol side-chain cleavage enzyme (P450scc) to form 22R-hydroxycholesterol, which is subsequently hydroxylated again by P450scc to form 20α,22R-dihydroxycholesterol, and finally the bond between carbons 20 and 22 is cleaved by P450scc to form pregnenolone ((3β)-3-hydroxypregn-5-en-20-one), the precursor to the steroid hormones.

Saringosterol is an isolate of Lessonia nigrescens that has activity against Mycobacterium tuberculosis.

27-Hydroxycholesterol (27-HC) is an endogenous oxysterol with multiple biological functions, including activity as a selective estrogen receptor modulator (SERM) (a mixed, tissue-specific agonist-antagonist of the estrogen receptor (ER)) and as an agonist of the liver X receptor (LXR). It is a metabolite of cholesterol that is produced by the enzyme CYP27A1.

Daucosterol (eleutheroside A) is a natural phytosterol-like compound. It is the glucoside of β-sitosterol.

4-Dehydroepiandrosterone (4-DHEA) is a steroid that is an isomer of 5-dehydroepiandrosterone.

Fungisterol is a bio-active sterol made by certain fungi.

'24S-Hydroxycholesterol (24S-HC), also known as cholest-5-ene-3,24-diol or cerebrosterol', is an endogenous oxysterol produced by neurons in the brain to maintain cholesterol homeostasis. It was discovered in 1953 by Alberto Ercoli, S. Di Frisco, and Pietro de Ruggieri, who first isolated the molecule in the horse brain and then demonstrated its presence in the human brain.

α-Spinasterol is a stigmastane-type phytosterol found in a variety of plant sources such as spinach, from which it gets its name.