Hubbry Logo
PregnanePregnaneMain
Open search
Pregnane
Community hub
Pregnane
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Pregnane
Pregnane
Pregnane
View on Wikipedia
from Wikipedia
Pregnane
Skeletal formula of pregnane
Ball-and-stick model of the pregnane molecule
Names
IUPAC name
5ξ-Pregnane[1]
Systematic IUPAC name
(1S,3aS,3bS,5aΞ,9aS,9bS,11aR)-1-Ethyl-9a,11a-dimethylhexadecahydro-1H-cyclopenta[a]phenanthrene
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
UNII
  • InChI=1S/C21H36/c1-4-15-9-11-18-17-10-8-16-7-5-6-13-20(16,2)19(17)12-14-21(15,18)3/h15-19H,4-14H2,1-3H3/t15-,16?,17-,18-,19-,20-,21+/m0/s1 checkY
    Key: JWMFYGXQPXQEEM-WZBAXQLOSA-N checkY
  • InChI=1/C21H36/c1-4-15-9-11-18-17-10-8-16-7-5-6-13-20(16,2)19(17)12-14-21(15,18)3/h15-19H,4-14H2,1-3H3/t15-,16?,17-,18-,19-,20-,21+/m0/s1
    Key: JWMFYGXQPXQEEM-WZBAXQLOBZ
  • C41CCCC[C@@]1([C@@H]3[C@H]([C@@H]2CC[C@@H]([C@@]2(C)CC3)CC)CC4)C
Properties
C21H36
Molar mass 288.511 g/mol
Density 0.926 g/ml
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Pregnane, also known as 17β-ethylandrostane or as 10β,13β-dimethyl-17β-ethylgonane, is a C21 steroid and, indirectly, a parent of progesterone. It is a parent hydrocarbon for two series of steroids stemming from 5α-pregnane (originally allopregnane) and 5β-pregnane (17β-ethyletiocholane). It has a gonane core.

5β-Pregnane is the parent of pregnanediones, pregnanolones, and pregnanediols, and is found largely in urine as a metabolic product of 5β-pregnane compounds.

Pregnanes

[edit]
Steroid nomenclature: Pregnanes have carbons 1 through 21.

Pregnanes are steroid derivatives with carbons present at positions 1 through 21.

Most biologically significant pregnane derivatives fall into one of two groups: pregnenes and pregnadienes. Another class is pregnatrienes.

Pregnenes

[edit]
Main article: Pregnene
Cortisone

Pregnenes have a double bond. Examples include:

Pregnadienes

[edit]
Main article: Pregnadiene
Cyproterone acetate

Pregnadienes have two double bonds. Examples include:

See also

[edit]

References

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Pregnane

View on Grokipedia
from Grokipedia
Pregnane is a crystalline with the molecular formula C₂₁H₃₆ that serves as the parent compound for several classes of steroid hormones, including progestogens such as progesterone and corticosteroids produced by the . Its systematic IUPAC name is (5S,8S,9S,10S,13R,14S,17S)-17-ethyl-10,13-dimethyl-2,3,4,5,6,7,8,9,11,12,14,15,16,17-tetradecahydro-1H-cyclopenta[a], featuring a characteristic tetracyclic gonane core with methyl groups at positions 10 and 13 and an ethyl at position 17. This exists in stereoisomeric forms, notably 5β-pregnane (also called pregnane) and 5α-pregnane (allopregnane), which differ at the A/B ring junction and influence the of their derivatives. Derivatives of pregnane play critical roles in reproductive physiology, stress response, and , with progesterone acting as a key hormone in maintenance and the . Pregnane-based neurosteroids, such as , modulate GABAA receptors in the , exerting , , and neuroprotective effects. Since the mid-20th century, synthetic pregnane derivatives have been widely used in as hormonal therapies, including oral contraceptives, agents like corticosteroids, and treatments for conditions such as and . These compounds are biosynthesized primarily in the gonads, adrenal glands, and through metabolism via enzymatic pathways involving enzymes.

Definition and Structure

Molecular Formula and Properties

Pregnane is the fully saturated parent of the pregnane class of , characterized by the molecular formula C₂₁H₃₆. This formula reflects its composition as a C21 derived from the gonane nucleus with an additional ethyl side chain. The of pregnane is 288.51 g/mol. For the 5α-isomer, the melting point is reported as 79–81 °C. Pregnane is insoluble in water, with a computed water solubility of approximately 10⁻⁶.⁵ mol/L, but it is soluble in organic solvents such as ethanol and chloroform. Structurally, pregnane features four fused rings labeled A, B, C, and D, where rings A, B, and C are six-membered and ring D is five-membered, following the standard steroid core configuration. The carbon atoms are numbered from 1 to 17 across the ring system, with an ethyl side chain (carbons 20 and 21) attached at position 17. This arrangement defines the parent scaffold for numerous steroid derivatives.

Steroid Core Configuration

The pregnane skeleton derives from the gonane core, a fundamental hydrocarbon consisting of four linearly fused rings: three six-membered rings designated as A, B, and C, and a five-membered ring D. The A ring fuses to B at positions 5-10, B to C at 8-9, and C to D at 13-14, forming the characteristic perhydrocyclopenta framework. The of the pregnane core features trans fusions at the B/C and C/D junctions, ensuring a relatively flat overall conformation across rings B, C, and D. Angular methyl groups are attached at C10 (β-oriented, designated C19) and C13 (β-oriented, designated C18), both projecting above the plane of the rings. At C17 (β-oriented), an ethyl (carbons C20 and C21, with C20 as methylene and C21 as methyl) extends above the plane, completing the C21 structure with formula C21H36. Textually, the core connectivity can be represented as a phenanthrene-like system with an additional fused cyclopentane: ring A (C1-C5,C10), ring B (C5-C10), ring C (C8-C9,C11-C14), and ring D (C13-C17), with the C17β-ethyl group as -CH₂-CH₃. Pregnane exhibits isomerism at the A/B junction, yielding 5α-pregnane (trans fusion, with hydrogen at C5 α-oriented) and 5β-pregnane (cis fusion, with hydrogen at C5 β-oriented). The 5α configuration imparts greater conformational stability due to the all-chair trans arrangement, and 5α-reduced pregnanes predominate in neurosteroid metabolism in the mammalian brain.

Nomenclature and Classification

IUPAC and Steroid Naming Conventions

The systematic IUPAC name for the parent pregnane, specifically the 5β-isomer, is (1S,3aS,3bS,5aS,9aS,9bS,11aR)-1-ethyl-9a,11a-dimethylhexadecahydro-1H-cyclopenta. For the 5α-isomer (also known as allopregnane), the configuration at the 5-position changes to 5aR, yielding (1S,3aS,3bS,5aR,9aS,9bS,11aR)-1-ethyl-9a,11a-dimethylhexadecahydro-1H-cyclopenta. These names describe the fully saturated tetracyclic structure with angular methyl groups at positions 10 and 13, and an ethyl at position 17, distinguishing pregnane (C21) from shorter-chain (C19) and longer-chain cholestane (C27). In the steroid numbering system, the carbon atoms in the ring structure are assigned numbers 1 through 17, with rings designated A (carbons 1-5, 10), B (5-10), C (8, 9, 11-14), and D (13-17). The angular methyl groups are numbered 18 (at C-13) and 19 (at C-10), while the at C-17 in pregnane consists of carbons 20 and 21. This numbering convention ensures consistent reference across derivatives and is retained in both trivial and systematic . Stereochemistry in steroid naming employs the Greek letters α and β to indicate the orientation of substituents relative to the plane of the ring system: α for positions below the plane and β for those above. Ring fusions, particularly at C-5, are specified using descriptors such as 5α (trans fusion between rings A and B) or 5β (cis fusion), which precede the parent name. Absolute configurations may also be denoted using R/S designations in systematic names, but α/β conventions are preferred for s to reflect biological relevance. The IUPAC-IUB definitive rules for steroid nomenclature, adopted in 1971, formalized these conventions based on earlier proposals from 1952 and the 1958 Basle Symposium, establishing "pregnane" as the trivial stem name for the C21 parent hydrocarbon to standardize naming across biochemical literature.

Categorization by Unsaturation

Pregnanes represent the fully saturated hydrocarbons in the pregnane series, characterized by a with no double bonds within the ring system. According to IUPAC recommendations, the parent is named "pregnane," consisting of a gonane core with an additional at C-10, a at C-13, and an at C-17. The degree of unsaturation in pregnane-based steroids is classified by the number of double bonds in the ring system, with reflecting this through systematic changes to the parent name. A single double bond results in "pregnene," indicated by replacing the "-ane" ending with "-ene" and specifying the position using the Δ notation (e.g., Δ4 for a bond between carbons 4 and 5), based on standard steroid numbering where the lower carbon atom receives the . In natural derivatives, this double bond is typically positioned at Δ4 or Δ5, influencing the conformational flexibility of the rings. Pregnadienes feature two double bonds, denoted by the ending "-adiene" with appropriate locants, often forming conjugated systems such as Δ4,6 or Δ1,4, which extend delocalization across adjacent rings. These configurations are prevalent in certain classes where the double bonds enhance structural rigidity. Unsaturation generally increases the planarity of the steroid rings, particularly in ring A, by restricting puckering and promoting flatter conformations, while conjugation between double bonds and nearby functional groups stabilizes the molecule through delocalized π-s and alters reactivity, such as facilitating electrophilic additions. Higher levels of unsaturation, like trienes (three double bonds, e.g., Δ5,7,9), are possible per but occur rarely in natural pregnanes compared to mono- and diunsaturated forms.

Biosynthesis

Pathway from Cholesterol in Animals

In animal steroidogenesis, the biosynthesis of pregnane derivatives begins with the conversion of to , a C21 Δ5-pregnene , catalyzed by the mitochondrial side-chain cleavage (CYP11A1, also known as P450scc). This rate-limiting reaction occurs on the and involves a three-step, six-electron oxidation : first, at the C22 position to form 22R-hydroxycholesterol; second, at the C20 position to yield 20R,22R-dihydroxycholesterol; and third, cleavage of the C20-C22 bond, producing and isocaproaldehyde as a . The exhibits high catalytic efficiency, with kinetic parameters such as a k_cat of approximately 56 min⁻¹ and a K_m of 0.16 mol per mol , enabling near-quantitative conversion of to once substrate delivery is achieved. This initial step is localized primarily in the mitochondria of steroidogenic tissues, including the , gonads (ovaries and testes), and , where serves as the first pregnane derivative and common precursor for all subsequent steroids. The transport of from the outer to the , essential for CYP11A1 access, is facilitated and rate-limited by the steroidogenic acute regulatory () protein, whose expression is upregulated by trophic hormones such as (ACTH) in the adrenal glands and (LH) or (FSH) in the gonads. ACTH and LH/FSH stimulate cAMP production, which in turn activates StAR transcription and promotes rapid cholesterol mobilization, ensuring efficient steroid precursor formation. Pregnenolone is then converted to progesterone, a key saturated pregnane, by the enzyme 3β-hydroxysteroid dehydrogenase/Δ5-Δ4 isomerase (3β-HSD), primarily through oxidation of the 3β-hydroxyl group to a ketone at C3 and isomerization of the double bond from Δ5 to Δ4, with NAD⁺ as the cofactor. This transformation occurs in the endoplasmic reticulum or mitochondria of the same steroidogenic tissues and is catalyzed by isoforms such as 3β-HSD1 and 3β-HSD2, yielding progesterone as the foundational Δ4-3-keto pregnane structure. The overall pathway from cholesterol to these initial pregnane derivatives is highly regulated to match physiological demands, with StAR-mediated delivery often representing the primary control point rather than the enzymatic steps themselves.

Synthesis in Plants and Microorganisms

In plants, the biosynthesis of pregnane derivatives primarily begins with phytosterols such as and β-sitosterol, which serve as precursors in contrast to the cholesterol-dependent pathway observed in animals. Side-chain cleavage of these phytosterols is catalyzed by endoplasmic reticulum-localized enzymes, including CYP108 and CYP150 homologs, producing as a key intermediate. Subsequent conversion to progesterone occurs via cytoplasmic 3β-hydroxysteroid dehydrogenases (3β-HSD), such as MtHSD5 and MtHSD6 in species like Marsdenia tenacissima, which isomerize the Δ5 and oxidize the 3β-hydroxyl group. This pathway exhibits lower yields compared to animal steroidogenesis due to competing routes, such as the diversion of toward brassinosteroid production, which shares early enzymatic steps. Notable examples of plant pregnane synthesis include the production of cardenolide precursors in species, where promiscuous CYP87A enzymes initiate the transformation of sterols to , followed by 5β-reductase activity to yield 5β-pregnane intermediates essential for cardiac s like digitoxigenin. In kombé, and phytosterols are directly incorporated into pregnane derivatives as part of cardenolide glycoside biosynthesis, highlighting the role of these compounds in plant defense mechanisms. These plant-specific routes often involve unique stereochemical modifications, such as the formation of 5β-pregnane configurations, differing from the 5α or Δ4-3-keto forms more common in other kingdoms. In microorganisms, pregnane synthesis occurs mainly through biotransformation of or phytosterols, particularly in actinomycetes like neoaurum and species, where side-chain degradation produces pregnane intermediates en route to in industrial processes. These employ enzymes such as CYP125 for initial C-26 of the side chain, followed by β-oxidation-like steps involving thiolases (e.g., FadA5) to cleave the chain and generate progesterone analogs. Fungi, including nigricans, contribute via selective modifications like 11α-hydroxylation of existing progesterone, enhancing yields of pharmaceutical intermediates such as 11α-hydroxyprogesterone. Some microbial systems, such as engineered , incorporate Δ24-reductases to process plant-derived 24-alkyl s into -like substrates before side-chain cleavage, achieving titers up to 420 mg/L. This microbial contrasts with synthesis by emphasizing degradative rather than anabolic pathways, often optimized for , and features enzymes localized differently from counterparts. For instance, bacterial P450s are membrane-bound but lack the strict compartmentalization seen in ER systems. Industrial applications leverage these transformations, with mycobacterial strains converting phytosterols to pregnane-derived synthons at scales supporting global drug production. Evolutionarily, steroidogenic enzymes in and microorganisms reflect convergent adaptations, with bacterial origins for core P450 and reductase activities transferred horizontally to eukaryotes, enabling independent elaboration of pregnane pathways across kingdoms in response to oxygenation events.

Major Derivatives

Saturated Pregnanes

Saturated pregnanes refer to the fully hydrogenated C21 derivatives lacking carbon-carbon double bonds in their tetracyclic core, distinguishing them from unsaturated pregnenes and pregnadienes. The parent structures, 5α-pregnane and 5β-pregnane, represent the saturated hydrocarbon skeletons with trans (A/B ring fusion) and cis (A/B ring fusion) configurations at the C5 position, respectively. These parent hydrocarbons are exceedingly rare in , occurring almost exclusively as synthetic compounds or as partially reduced intermediates in metabolic pathways, rather than as free entities. The most prominent saturated pregnanes are oxygenated metabolites derived from progesterone or , including (3α-hydroxy-5β-pregnan-20-one) and (3α-hydroxy-5α-pregnan-20-one). These compounds arise through stereospecific reduction of the Δ4-3-keto group in their precursors, catalyzed by 5β-reductase (AKR1D1) for the 5β-series and 5α-reductases (SRD5A1 and SRD5A2) for the 5α-series, followed by 20-ketone reduction and 3α-hydroxylation via aldo-keto reductases such as AKR1C1–4. As neurosteroids, both and potently enhance GABA_A receptor function by binding to distinct allosteric sites, increasing chloride conductance and promoting inhibitory neurotransmission in the . , in particular, exhibits nanomolar potency in modulating GABA_A receptors, contributing to and effects. The saturation of the pregnane core imparts , rendering these molecules resistant to electrophilic additions or isomerizations common in unsaturated steroids. In vivo, however, saturated pregnanes remain vulnerable to enzymatic oxidation, primarily by isoforms that introduce hydroxyl groups at various positions, facilitating their clearance. They occur predominantly as metabolites in urine, where they are excreted as conjugates following phase II metabolism during and stress responses, and in the , where local synthesis supports neuromodulatory roles without serving as primary circulating hormones.

Monounsaturated Pregnenes

Monounsaturated pregnenes are a class of C21 steroids characterized by a single double bond in the steroid ring system, typically at the Δ4 or Δ5 position, which imparts specific reactivity and biological roles as hormonal precursors. These compounds serve as key intermediates in steroid hormone biosynthesis, with the double bond influencing their conjugation and metabolic conversion. Representative structures include progesterone, systematically named as pregn-4-ene-3,20-dione, which features a Δ4 double bond between carbons 4 and 5 in ring A of the pregnane skeleton. Another prominent example is pregnenolone, or pregn-5-en-3β-ol-20-one, distinguished by its Δ5 double bond between carbons 5 and 6, positioning it as an early intermediate in the pathway. The functional groups in monounsaturated pregnenes commonly include at positions C3 and C20, as seen in progesterone, which contribute to its progestogenic activity by enabling interactions with receptors. In contrast, bears a at C20 and a hydroxyl group at C3β, with the position of hydroxyls varying across derivatives to modulate and enzymatic susceptibility. These groups, combined with the unsaturation, facilitate and reduction reactions . arises from via side-chain cleavage and acts as the universal precursor for all subsequent hormones in animals. Progesterone, synthesized downstream from , is abundantly produced in the of the during the , where it reaches concentrations supporting endometrial preparation for implantation. Synthetic analogs of monounsaturated pregnenes have been developed to enhance stability and potency, with serving as a foundational structure for progestins used in medical applications. This analog introduces a hydroxyl at C17α, altering its while retaining core progestational effects. Spectroscopic identification of Δ4-3-keto monounsaturated pregnenes, such as progesterone, relies on their characteristic absorption maximum at 240 nm, arising from the conjugated enone system in ring A, which aids in analytical detection and purity assessment.

Diunsaturated Pregnadienes

Diunsaturated pregnadienes are a subclass of pregnane steroids characterized by the presence of two double bonds in the A-ring of the steroid nucleus, typically forming conjugated systems that confer enhanced biological activity compared to their monounsaturated counterparts. The predominant structural motif is the Δ^{1,4}-pregnadiene-3,20-dione core, where double bonds are located between carbons 1-2 and 4-5, conjugated with a ketone at position 3, which extends the π-electron system and influences molecular planarity and receptor interactions. This conjugation stabilizes the enone system, contributing to increased lipophilicity and receptor affinity. Alternative diunsaturated configurations, such as Δ^{4,6}-pregnadienes, feature non-conjugated double bonds between carbons 4-5 and 6-7, and are less common in pharmacological applications but appear in certain synthetic analogs. Key examples of Δ^{1,4}-pregnadienes include prednisolone, systematically named (11β)-11,17,21-trihydroxypregna-1,4-diene-3,20-dione, which serves as a foundational structure with hydroxyl groups at positions 11, 17, and 21. , or 17,21-dihydroxypregna-1,4-diene-3,11,20-trione, is the 11-dehydro analog of prednisolone and functions as a that is metabolically converted to the active form . Another prominent derivative is dexamethasone, (8S,9R,10S,11S,13S,14S,16R,17R)-9-fluoro-11,17-dihydroxy-17-(2-hydroxyacetyl)-10,13,16-trimethyl-6,7,8,9,10,11,12,13,14,15,16,17-dodecahydro-3H-cyclopentaphenanthren-3-one, incorporating the Δ^{1,4}- system alongside a 9α-fluoro and 16α-methyl group for augmented potency. The conjugated Δ^{1,4}-diene system enhances binding to the by promoting a more planar A-ring conformation, which improves hydrophobic interactions within the receptor's ligand-binding pocket and increases transcriptional activation efficiency. This structural feature typically results in increased receptor affinity compared to Δ^4-monoenes, while reducing activity by altering side-chain orientation. In Δ^{4,6}-pregnadienes, the shifted unsaturation may modulate steric hindrance but generally yields lower receptor selectivity. Structural modifications further optimize these compounds for therapeutic use; for instance, 9α-fluorination in dexamethasone sterically hinders enzymatic deactivation and strengthens hydrogen bonding with receptor residues, yielding up to 25-fold greater potency relative to . Acetylation at the 21-position, as in , improves and without compromising the conjugation. Such alterations are strategically introduced to balance efficacy, duration of action, and side-effect profile. Certain synthetic progestins, such as derivatives of , also incorporate diunsaturated systems for enhanced therapeutic profiles in hormonal therapies. Natural diunsaturated pregnadienes are exceedingly rare in biological systems, with most endogenous glucocorticoids like featuring only a single Δ^4 ; instead, these compounds are predominantly semi-synthetic, derived from progesterone through microbial 1,2-dehydrogenation or chemical oxidation to install the additional unsaturation. This biosynthetic allows precise tailoring of the system for pharmaceutical applications.

Biological and Pharmacological Significance

Hormonal and Metabolic Roles

Pregnane derivatives, particularly progesterone, play essential roles in reproductive physiology. Progesterone maintains the uterine lining during by promoting endometrial and inhibiting myometrial contractions, thereby supporting implantation and fetal development. It also regulates the by acting through progesterone receptors (PR) to induce secretory changes in the during the , preparing for potential pregnancy or facilitating if implantation does not occur. These actions ensure cyclic ovarian function and reproductive readiness. Corticosteroids derived from pregnane, such as , are pivotal in metabolic and stress responses. mediates the body's adaptation to stress by mobilizing energy reserves, including the promotion of in the liver to increase blood glucose levels during acute challenges. It also exerts immunosuppressive effects by binding to receptors (GR), which downregulate pro-inflammatory cytokines and inhibit immune cell activity, thereby preventing excessive . These functions help maintain under physiological stress. Neurosteroids like , a pregnane metabolite, influence neurological processes through modulation of GABA_A receptors. enhances GABAergic inhibition, producing anxiolytic effects by reducing neuronal excitability in brain regions associated with anxiety, such as the . It also promotes and improves sleep architecture by potentiating tonic GABA_A currents in the and cortex. These actions contribute to mood regulation and stress resilience. Metabolic end-products of pregnane derivatives provide diagnostic insights into endocrine function. Pregnanediols, primary urinary metabolites of progesterone such as pregnanediol-3-glucuronide, reflect ovarian progesterone production and are used to assess adequacy and status. Elevated levels in urine indicate active function, serving as non-invasive markers of reproductive health. Disruptions in pregnane-related pathways underlie certain endocrine disorders. (CAH) arises from genetic defects in enzymes like (CYP21A2) or (CYP17A1), which impair synthesis from pregnane precursors such as progesterone and , leading to and excess. These deficiencies disrupt the steroidogenic pathway, causing symptoms like salt-wasting crises in severe cases and in others.

Therapeutic Applications

Pregnane derivatives have been pivotal in the development of synthetic hormones since the , when chemists synthesized 19-norpregnanes, such as norethindrone, to create orally active progestins for contraception. These modifications, involving the removal of the at position 19 and alterations like ethynylation at C17, enhanced progestational potency and through structure-activity relationship (SAR) studies that optimized receptor binding and metabolic stability. This era marked the transition from injectable natural progesterone to effective oral formulations, revolutionizing . Progestins derived from pregnane, including norethindrone and , are widely used in hormonal contraceptives to prevent and endometrial proliferation, as well as in (HRT) to manage menopausal symptoms and protect against estrogen-induced endometrial hyperplasia. However, these agents carry risks of venous , such as deep vein thrombosis and , particularly in postmenopausal women on HRT, due to procoagulant effects on clotting factors. Glucocorticoid pregnane derivatives like and dexamethasone serve as potent agents, treating conditions such as exacerbations by suppressing immune responses and production. Long-term use, however, increases the risk of through accelerated and reduced calcium absorption, necessitating monitoring and supplementation with calcium and . In current clinical practice, pregnane-based glucocorticoids function as adjuncts in regimens to mitigate inflammation, nausea, and reactions associated with antineoplastic agents. They also play a key role in organ transplant , often as part of induction and maintenance protocols to prevent acute rejection by inhibiting T-cell activation. Emerging therapeutic applications include selective progesterone receptor modulators (SPRMs), such as , which act as partial agonists or antagonists at the to provide effective by delaying even after luteinizing hormone surge initiation. These agents offer advantages over traditional progestins by maintaining efficacy in the advanced , with ulipristal approved for use up to 120 hours post-unprotected intercourse. Pregnane-based neurosteroids have therapeutic applications in . , a synthetic analog of , was approved by the U.S. in 2023 as the first oral treatment for in adults. It functions as a positive of GABA_A receptors, offering rapid and sustained effects with a two-week course of once-daily dosing.

References

  1. https://www.merriam-webster.com/medical/pregnane
  2. https://www.tabers.com/tabersonline/view/Tabers-Dictionary/753200/0/pregnane
  3. https://pubchem.ncbi.nlm.nih.gov/compound/Pregnane
  4. https://webbook.nist.gov/cgi/cbook.cgi?ID=C481265
  5. https://www.nature.com/articles/pr2003435
  6. https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/pregnane
  7. https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2024.1430781/full
  8. https://www.steraloids.com/5pregnan/pregn-based/5-pregnane.html
  9. https://www.chemeo.com/cid/17-648-4/Pregnane
  10. http://publications.iupac.org/pac/1989/pdf/6110x1783.pdf
  11. https://iupac.qmul.ac.uk/steroid/3S01.html
  12. https://pubs.acs.org/doi/10.1021/acsomega.3c08963
  13. https://www.sciencedirect.com/topics/medicine-and-dentistry/pregnane-derivative
  14. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/pregnenolone
  15. https://pmc.ncbi.nlm.nih.gov/articles/PMC6264551/
  16. https://pmc.ncbi.nlm.nih.gov/articles/PMC10716780/
  17. https://pmc.ncbi.nlm.nih.gov/articles/PMC3121847/
  18. https://pmc.ncbi.nlm.nih.gov/articles/PMC3286270/
  19. https://pmc.ncbi.nlm.nih.gov/articles/PMC8205265/
  20. https://pmc.ncbi.nlm.nih.gov/articles/PMC7219929/
  21. https://pmc.ncbi.nlm.nih.gov/articles/PMC3283258/
  22. https://pmc.ncbi.nlm.nih.gov/articles/PMC6044331/
  23. https://pmc.ncbi.nlm.nih.gov/articles/PMC6993601/
  24. https://pmc.ncbi.nlm.nih.gov/articles/PMC3943232/
  25. https://pubmed.ncbi.nlm.nih.gov/7637579/
  26. https://doi.org/10.1016/j.ymben.2025.03.016
  27. https://doi.org/10.1016/S0031-9422(00)85797-0
  28. https://doi.org/10.1111/j.1751-7915.2012.00331.x
  29. https://doi.org/10.1186/s12934-024-02385-2
  30. https://doi.org/10.1073/pnas.2101276118
  31. https://pmc.ncbi.nlm.nih.gov/articles/PMC3971473/
  32. https://pmc.ncbi.nlm.nih.gov/articles/PMC3825703/
  33. https://pmc.ncbi.nlm.nih.gov/articles/PMC3356040/
  34. https://pmc.ncbi.nlm.nih.gov/articles/PMC7231972/
  35. https://pmc.ncbi.nlm.nih.gov/articles/PMC11897187/
  36. https://pubchem.ncbi.nlm.nih.gov/compound/Progesterone
  37. https://pubchem.ncbi.nlm.nih.gov/compound/Pregnenolone
  38. https://pmc.ncbi.nlm.nih.gov/articles/PMC6857441/
  39. https://pmc.ncbi.nlm.nih.gov/articles/PMC8946127/
  40. https://joe.bioscientifica.com/view/journals/joe/44/1/joe_44_1_011.pdf
  41. https://pmc.ncbi.nlm.nih.gov/articles/PMC2650492/
  42. https://www.steraloids.com/pregnadiene/pregn-based/4-6-pregnadiene-11-17-21-triol-3-20-dione
  43. https://webbook.nist.gov/cgi/cbook.cgi?ID=C50248&Mask=4
  44. https://www.drugs.com/pro/prednisone.html
  45. https://go.drugbank.com/drugs/DB01234
  46. https://pubmed.ncbi.nlm.nih.gov/10375032/
  47. https://patents.google.com/patent/US2891079A/en
  48. https://go.drugbank.com/drugs/DB00860
  49. https://pubchem.ncbi.nlm.nih.gov/compound/Medroxyprogesterone-acetate
  50. https://www.ncbi.nlm.nih.gov/books/NBK558960/
  51. https://pmc.ncbi.nlm.nih.gov/articles/PMC8640821/
  52. https://www.ncbi.nlm.nih.gov/books/NBK500020/
  53. https://www.ncbi.nlm.nih.gov/books/NBK538239/
  54. https://www.ncbi.nlm.nih.gov/books/NBK560897/
  55. https://pmc.ncbi.nlm.nih.gov/articles/PMC10706127/
  56. https://pmc.ncbi.nlm.nih.gov/articles/PMC5469411/
  57. https://pmc.ncbi.nlm.nih.gov/articles/PMC6279762/
  58. https://pmc.ncbi.nlm.nih.gov/articles/PMC5990994/
  59. https://www.ncbi.nlm.nih.gov/books/NBK448098/
  60. https://pmc.ncbi.nlm.nih.gov/articles/PMC5576025/
  61. https://embryo.asu.edu/pages/progestin-synthetic-progesterone
  62. https://pmc.ncbi.nlm.nih.gov/articles/PMC10218893/
  63. https://www.pbs.org/wgbh/americanexperience/features/pill-development-synthetic-hormones/
  64. https://www.mdpi.com/2077-0383/12/10/3388
  65. https://www.drugs.com/sfx/medroxyprogesterone-side-effects.html
  66. https://ashpublications.org/hematology/article/2024/1/644/526191/Estrogen-progestin-and-beyond-thrombotic-risk-and
  67. https://www.mayoclinic.org/tests-procedures/cortisone-shots/in-depth/steroids/art-20045692
  68. https://theros.org.uk/information-and-support/osteoporosis/causes/steroids/
  69. https://go.drugbank.com/categories/DBCAT000748
  70. https://www.uspharmacist.com/article/immunosuppressants-used-in-solid-organ-transplantation
  71. https://pubmed.ncbi.nlm.nih.gov/32365199/
  72. https://www.sciencedirect.com/science/article/pii/S0010782425000538
  73. https://www.fda.gov/news-events/press-announcements/fda-approves-first-oral-treatment-postpartum-depression
Add your contribution
Related Hubs
User Avatar
No comments yet.