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Azasteroids
An azasteroid is a type of steroid derivative which has one of the carbon atoms in the steroid ring system replaced by a nitrogen atom. Two azasteroids, finasteride and dutasteride, are used clinically as 5α-reductase inhibitor 5α-Reductases, also known as 3-oxo-5α-steroid 4-dehydrogenases, are enzymes involved in steroid metabolism. They participate in three metabolic pathways: bile acid biosynthesis, androgen and estrogen metabolism. There are three isozymes of ...s. Some of the 6-azasteroids may prove to be useful drugs, but have yet to reach the pharmaceutical market. References Steroids {{pharmacology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azasteroid Pharmaceuticals
An azasteroid is a type of steroid derivative which has one of the carbon atoms in the steroid ring system replaced by a nitrogen atom. Two azasteroids, finasteride and dutasteride, are used clinically as 5α-reductase inhibitor 5α-Reductases, also known as 3-oxo-5α-steroid 4-dehydrogenases, are enzymes involved in steroid metabolism. They participate in three metabolic pathways: bile acid biosynthesis, androgen and estrogen metabolism. There are three isozymes of ...s. Some of the 6-azasteroids may prove to be useful drugs, but have yet to reach the pharmaceutical market. References Steroids {{pharmacology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steroid
A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and as signaling molecules. Hundreds of steroids are found in plants, animals and fungi. All steroids are manufactured in cells from the sterols lanosterol (opisthokonts) or cycloartenol (plants). Lanosterol and cycloartenol are derived from the cyclization of the triterpene squalene. The steroid core structure is typically composed of seventeen carbon atoms, bonded in four " fused" rings: three six-member cyclohexane rings (rings A, B and C in the first illustration) and one five-member cyclopentane ring (the D ring). Steroids vary by the functional groups attached to this four-ring core and by the oxidation state of the rings. Sterols are forms of steroids with a hydroxy group at position three and a skeleton derived from cholestane. ''A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Derivative
In chemistry, a derivative is a compound that is derived from a similar compound by a chemical reaction. In the past, derivative also meant a compound that ''can be imagined to'' arise from another compound, if one atom or group of atoms is replaced with another atom or group of atoms, but modern chemical language now uses the term structural analog for this meaning, thus eliminating ambiguity. The term "structural analogue" is common in organic chemistry. In biochemistry, the word is used for compounds that at least theoretically can be formed from the precursor compound. Chemical derivatives may be used to facilitate analysis. For example, melting point (MP) analysis can assist in identification of many organic compounds. A crystalline derivative may be prepared, such as a semicarbazone or 2,4-dinitrophenylhydrazone (derived from aldehydes or ketones), as a simple way of verifying the identity of the original compound, assuming that a table of derivative MP values is available ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon
Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with other atoms when it forms chemical compounds or molecules. Description The combining capacity, or affinity of an ...—its atom making four electrons available to form covalent bond, covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon makes up only about 0.025 percent of Earth's crust. Three Isotopes of carbon, isotopes occur naturally, Carbon-12, C and Carbon-13, C being stable, while Carbon-14, C is a radionuclide, decaying with a half-life of about 5,730 years. Carbon is one of the Timeline of chemical element discoveries#Ancient discoveries, few elements known since antiquity. Carbon is the 15th Abundance of elements in Earth's crust, most abundant element in the Earth's crust, and the Abundance of the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seventh in total abundance in the Milky Way and the Solar System. At standard temperature and pressure, two atoms of the element bond to form N2, a colorless and odorless diatomic gas. N2 forms about 78% of Earth's atmosphere, making it the most abundant uncombined element. Nitrogen occurs in all organisms, primarily in amino acids (and thus proteins), in the nucleic acids ( DNA and RNA) and in the energy transfer molecule adenosine triphosphate. The human body contains about 3% nitrogen by mass, the fourth most abundant element in the body after oxygen, carbon, and hydrogen. The nitrogen cycle describes the movement of the element from the air, into the biosphere and organic compounds, then back into the atmosphere. Many indus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Finasteride
Finasteride, sold under the brand names Proscar and Propecia among others, is a medication used to treat hair loss and benign prostatic hyperplasia (BPH) in men. It can also be used to treat excessive hair growth in women and as a part of hormone therapy for transgender women. It is taken by mouth. Finasteride is a 5α-reductase inhibitor and therefore an antiandrogen. It works by decreasing the production of dihydrotestosterone (DHT) by about 70%, including in the prostate gland and the scalp. In addition to DHT, finasteride also inhibits the production of several anticonvulsant neurosteroids including allopregnanolone, androstanediol, and THDOC. Adverse effects from finasteride are rare, however some men experience sexual dysfunction, depression, and breast enlargement. In some men, sexual dysfunction may persist after stopping the medication. It may also hide the early symptoms of certain forms of prostate cancer. Finasteride was patented in 1984 and approved for med ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dutasteride
Dutasteride, sold under the brand name Avodart among others, is a medication primarily used to treat the symptoms of a benign prostatic hyperplasia (BPH), an enlarged prostate not associated with cancer. A few months may be required before benefits occur. It is also used for scalp hair loss in men and as a part of hormone therapy in transgender women. It is usually taken by mouth. The most commonly reported side effects of dutasteride, although rare, include sexual dysfunction and depression. In the largest available study of 6,729 men with BPH, 9% experienced erectile dysfunction (compared to 5.7% treated with a placebo), 3.3% experienced decreased sex drive (vs 1.6% of placebo), and 1.9% had enlarged breasts (vs 1% of placebo). Exposure during pregnancy is specifically contraindicated because antiandrogens such as dutasteride have been shown to interfere with the sexual development of male fetuses. Dutasteride was patented in 1993 by GlaxoSmithKline and was approved for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5α-reductase Inhibitor
5α-Reductases, also known as 3-oxo-5α-steroid 4-dehydrogenases, are enzymes involved in steroid metabolism. They participate in three metabolic pathways: bile acid biosynthesis, androgen and estrogen metabolism. There are three isozymes of 5α-reductase encoded by the genes SRD5A1, SRD5A2, and SRD5A3. 5α-Reductases catalyze the following generalized chemical reaction: :a 3-oxo-5α-steroid + acceptor a 3-oxo-Δ4-steroid + reduced acceptor Where a 3-oxo-5α-steroid and acceptor are substrates, and a corresponding 3-oxo-Δ4-steroid and the reduced acceptor are products. An instance of this generalized reaction that 5α-reductase type 2 catalyzes is: :dihydrotestosterone + NADP+ \rightleftharpoons testosterone + NADPH + H+ where dihydrotestosterone is the 3-oxo-5α-steroid, NADP+ is the acceptor and testosterone is the 3-oxo-Δ4-steroid and NADPH the reduced acceptor. Production and activity The enzyme is produced in many tissues in both males and females, in the rep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
