Steroid

A Steroid is a lipid molecule characterized by a four-ring carbon structure consisting of three cyclohexane rings and one cyclopentane ring arranged in a specific configuration.

• AKA: Steroid Molecule, Steroidal Compound, Sterane Derivative.
• Context:
  • It can typically contain 17 Carbon Atoms in its core structure.
  • It can typically have Rings labeled A, B, C, and D in standard nomenclature.
  • It can typically be derived from Squalene through biosynthetic pathways.
  • It can typically exhibit Stereochemistry with specific 3D configurations.
  • It can typically be modified by Functional Groups determining biological activity.
  • It can typically show Hydrophobic Properties due to hydrocarbon structure.
  • It can typically undergo Enzymatic Modification at various carbon positions.
  • It can typically be synthesized from Acetyl-CoA via mevalonate pathway.
  • It can typically have Chiral Centers creating stereoisomers.
  • It can typically be classified by functional groups and saturation state.
  • ...
  • It can often contain Hydroxyl Groups, ketone groups, or aldehyde groups.
  • It can often have Double Bonds in specific ring positions.
  • It can often undergo Phase I Metabolism through oxidation and reduction.
  • It can often be conjugated in Phase II Metabolism for excretion.
  • It can often accumulate in Lipid-Rich Tissues due to lipophilicity.
  • It can often cross Biological Membranes without transporters.
  • It can often be detected by Chromatography and mass spectrometry.
  • It can often form Crystal Structures with characteristic melting points.
  • ...
  • It can range from being a Natural Steroid to being a Synthetic Steroid, depending on its origin source.
  • It can range from being a Simple Steroid to being a Complex Steroid, depending on its functional group complexity.
  • It can range from being a Saturated Steroid to being an Unsaturated Steroid, depending on its double bond presence.
  • It can range from being a Biologically Active Steroid to being an Inactive Steroid, depending on its physiological effect.
  • ...
  • It can be found in Animals, plants, and fungi.
  • It can serve as precursor for Steroid Hormones, bile acids, and vitamin D.
  • It can function as Membrane Components like cholesterol.
  • It can have Pharmaceutical Applications as drugs.
  • It can be named using IUPAC Nomenclature based on gonane or estrane.
  • ...
• Example(s):
  • Cholesterol, the primary animal steroid and precursor for steroid hormones.
  • Steroid Hormones, such as:
    • Cortisol, a glucocorticoid regulating metabolism.
    • Testosterone, an androgen controlling male characteristics.
    • Estradiol, an estrogen regulating female reproduction.
    • Aldosterone, a mineralocorticoid controlling electrolyte balance.
  • Bile Acids, such as:
    • Cholic Acid, facilitating lipid digestion.
    • Chenodeoxycholic Acid, a primary bile acid.
    • Deoxycholic Acid, a secondary bile acid.
  • Plant Steroids, such as:
    • Phytosterols, including β-sitosterol and stigmasterol.
    • Brassinosteroids, serving as plant hormones.
    • Cardiac Glycosides like digoxin.
  • Synthetic Steroids, such as:
    • Anabolic Steroids like nandrolone.
    • Corticosteroid Medications like prednisone.
    • Contraceptive Steroids like norethindrone.
  • Vitamin D Compounds, such as:
    • Cholecalciferol (Vitamin D3).
    • Ergocalciferol (Vitamin D2).
    • Calcitriol, the active form.
  • Sterols, such as:
    • Ergosterol in fungi.
    • Lanosterol, a cholesterol precursor.
    • 7-Dehydrocholesterol in skin.
  • ...
• Counter-Example(s):
  • Fatty Acid, which are linear hydrocarbon chains rather than ring structures.
  • Phospholipid, which contain phosphate groups and lack steroid rings.
  • Prostaglandin, which are eicosanoids with different carbon skeletons.
  • Terpene, which may have rings but different structural arrangements.
  • Alkaloid, which are nitrogen-containing compounds with different core structures.
  • Carbohydrate, which are polyhydroxy compounds without steroid scaffolds.
• See: Lipid, Cholesterol, Steroid Hormone, Bile Acid, Four-Ring Structure, Lipophilic Molecule, Steroid Biosynthesis, Nuclear Receptor, Endocrine System, Membrane Lipid, Pharmaceutical Steroid, IUPAC Nomenclature.

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References

2020

• (Wikipedia, 2020) ⇒ https://en.wikipedia.org/wiki/steroid Retrieved:2020-4-21.
  • 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 which 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. Steroids can also be more radically modified, such as by changes to the ring structure, for example, cutting one of the rings. Cutting Ring B produces secosteroids one of which is vitamin D₃. Examples include the lipid cholesterol, the sex hormones estradiol and testosterone, and the anti-inflammatory drug dexamethasone.

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