Pregnenolone
Systematic (IUPAC) name
3β-hydroxypregn-5-en-20-one
Identifiers
CAS number	145-13-1
ATC code	?
PubChem	8955
DrugBank	EXPT02608
Chemical data
Formula	C21H32O2
Mol. mass	316. IUPAC Nomenclature is a system of naming Chemical compounds and of describing the science of Chemistry in general CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to The Anatomical Therapeutic Chemical Classification System is used for the classification of drugs It is controlled by the WHO Collaborating Centre for Drug PubChem is a Database of chemical Molecules The system is maintained by the National Center for Biotechnology Information (NCBI a component The DrugBank database available at the University of Alberta is a unique Bioinformatics and Cheminformatics resource that combines detailed drug (i A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the The molecular mass (abbreviated m of a substance, more commonly referred to as molecular weight and abbreviated as MW, is the Mass of one 483 g/mol
Pharmacokinetic data
Bioavailability	?
Metabolism	?
Half life	?
Excretion	?
Therapeutic considerations
Pregnancy cat.	?
Legal status
Routes	?

Pregnenolone is a steroid hormone involved in the steroidogenesis of progesterone, mineralocorticoids, glucocorticoids, androgens, and estrogens. In Pharmacology, bioavailability is used to describe the fraction of an administered Dose of unchanged drug that reaches the Systemic circulation, one of Drug metabolism is the Metabolism of drugs, their Biochemical modification or degradation usually through specialized enzymatic systems The biological half-life of a substance is the time it takes for a substance (drug radioactive nuclide or other to lose half of its pharmacologic physiologic or radiologic activity Excretion is the process of eliminating waste products of Metabolism and other non-useful materials The pregnancy category of a pharmaceutical agent is an assessment of the risk of fetal injury due to the pharmaceutical if it is used as directed by the mother during The regulation of therapeutic goods, that is drugs and therapeutic devices, varies by jurisdiction In Pharmacology and Toxicology, a route A steroid is a Terpenoid Lipid characterized by a Carbon skeleton with four fused rings generally arranged in a 6-6-6-5 fashion Steroid metabolism is the complete set of Chemical reactions in organisms that produce modify and consume Steroids These Metabolic pathways include Progesterone is a C-21 Steroid Hormone involved in the Female Menstrual cycle, Pregnancy (supports Gestation Mineralocorticoids are a class of Steroid hormones characterised by their similarity to Aldosterone and their influence on salt and water balance Glucocorticoids (GC are a class of Steroid hormones characterised by an ability to bind with the glucocorticoid receptor ( GR) and trigger similar effects Androgen is the generic term for any natural or synthetic compound usually a Steroid Hormone, that stimulates or controls the development and maintenance of masculine Estrogens (US otherwise oestrogens or œstrogens) are a group of Steroid compounds named for their importance in the Estrous cycle, As such it is a prohormone. A prohormone is a substance that is a precursor to a Hormone, usually having minimal hormonal effect by itself

Contents 1 Chemistry 2 Synthesis 3 Prohormone 4 Neurosteroid 5 Additional images 6 References

Chemistry

Like other steroids, pregnenolone consists of four interconnected cyclic hydrocarbons. A steroid is a Terpenoid Lipid characterized by a Carbon skeleton with four fused rings generally arranged in a 6-6-6-5 fashion In Organic chemistry, a hydrocarbon is an Organic compound consisting entirely of Hydrogen and Carbon. It contains ketone and hydroxyl functional groups, two methyl branches, and a double bond at C5, in the B cyclic hydrocarbon ring. A ketone (pronounced as key tone) is either the Functional group characterized by a Carbonyl group (O=C linked to two other Carbon atoms or Hydroxyl in Chemistry stands for a molecule consisting of an Oxygen atom and a Hydrogen atom connected by a Covalent bond. In Chemistry, a methyl group is a Hydrophobic Alkyl Functional group named after Methane (4 Like all steroid hormones, it is hydrophobic. In Chemistry, hydrophobicity (from the combining form of water in Attic Greek hydro- and for fear phobos) refers to the physical property of Its esterified version, pregnenolone sulfate, is water-soluble.

Synthesis

Pregnenolone is synthesized from cholesterol. Progesterone is a C-21 Steroid Hormone involved in the Female Menstrual cycle, Pregnancy (supports Gestation Cholesterol is a Lipid found in the Cell membranes and transported in the Blood plasma of all Animals It is an essential component of mammalian This conversion involves hydroxylation at the side-chain at C20 and C22 positions, with cleavage of the side-chain. A side chain in Organic chemistry and Biochemistry is a part of a Molecule that is attached to a core structure The enzyme performing this task is cytochrome P450scc, located in the mitochondria, and controlled by pituitary tropic hormones, such as ACTH, FSH, LH. Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins Cytochrome P450 family 11 subfamily A polypeptide 1, also known as CYP11A1, is a human Gene. In Cell biology, a mitochondrion (plural mitochondria) is a membrane-enclosed Organelle found in most eukaryotic cells. Adrenocorticotropic hormone ( ACTH or corticotropin) is a Polypeptide Hormone produced and secreted by the Pituitary gland

Prohormone

Pregnenolone undergoes further steroid metabolism in one of three ways.

• Pregnenolone can be converted to progesterone. Progesterone is a C-21 Steroid Hormone involved in the Female Menstrual cycle, Pregnancy (supports Gestation The critical enzyme step is two-fold using a 3-beta-hydroxysteroid dehydrogenase and a delta 4-5 isomerase. 3-beta-HSD (or 3-beta-hydroxysteroid dehydrogenase-isomerase) is an Enzyme which catalyses the synthesis of Progesterone from Pregnenolone, 17-hydroxyprogesterone The latter transfers the double bond from C5 to C4 on the A ring. Progesterone is the entry into the delta-4-pathway, resulting in production of 17-hydroxy progesterone and androstenedione, precursor to testosterone and estrone. Androstenedione (also known as 4-androstenedione) is a 19- Carbon Steroid Hormone produced in the Adrenal glands and the Gonads Testosterone is a Steroid hormone from the Androgen group In mammals testosterone is primarily secreted in the testes of males and the Ovaries Estrone (also oestrone) is an Estrogenic Hormone secreted by the Ovary. Aldosterone and corticosteroids are also derived from progesterone or its derivatives. Aldosterone is a hormone that causes the tubules of the kidneys to retain sodium and water Corticosteroids are a class of Steroid hormones that are produced in the Adrenal cortex.

• Pregnenolone can be converted to 17-hydroxy-pregnenolone by the enzyme 17α-hydroxylase (CYP17A1). CYP17A1 (also known as 17&alpha-hydroxylase/1720 lyase/1720 desmolase) is a Cytochrome P450 enzyme which acts upon Pregnenolone and Progesterone Using this pathway, termed delta-5 pathway, the next step is conversion to dehydroepiandrosterone (DHEA) using a desmolase. Dehydroepiandrosterone ( DHEA) is a natural Steroid Prohormone produced from Cholesterol by the Adrenal glands the Gonads DHEA is the precursor of androstenedione.

• Pregnenolone can be converted to androsta-5,16-dien-3 beta-ol by 16-ene synthetase.

Neurosteroid

Pregnenolone and its sulfate, like dehydroepiandrosterone and its sulfate and progesterone, belong to the group of neurosteroids that are found in high concentrations in certain areas in the brain, and are synthesized there. Dehydroepiandrosterone ( DHEA) is a natural Steroid Prohormone produced from Cholesterol by the Adrenal glands the Gonads Neuroactive Steroids (or neurosteroids') rapidly alter Neuronal excitability through interaction with Neurotransmitter[[ligand gated ion channel|-gated Neurosteroids affect synaptic functioning, are neuroprotective, and enhance myelinization. The term neuroprotection refers to mechanisms within the Nervous system which protect Neurons from Apoptosis or Degeneration, for example following Myelin is an electrically-insulating Dielectric Phospholipid layer that surrounds only the Axons of many Neurons It is an outgrowth Pregnenolone and its sulfate ester are under investigation for their potential to improve cognitive and memory functioning. In Psychology, memory is an organism's ability to store retain and subsequently retrieve information ^[1]

Additional images

Steroidogenesis

Cholesterol

Progesterone

References

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