Cholesterol Chemical Structure

1. Identification

Summary

Cholesterol is an endogenous sterol (cholest-5-en-3β-ol) essential for mammalian cell membranes, precursor of bile acids, steroid hormones, and vitamin D, and a major cargo of lipoproteins (HDL, LDL, VLDL).

Brand Names

Not applicable (endogenous biomolecule; bulk chemical/excipient).

Name

Cholesterol

Background

Core membrane lipid that modulates fluidity and raft microdomains; central node of hepatic and intestinal sterol homeostasis (synthesis, dietary uptake, reverse transport). Widely used as an excipient and in liposomes.

Modality

Small molecule

Groups

Endogenous biomolecule; excipient

Structure

Cholesterol 2D chemical structure (cholest-5-en-3β-ol). Formula C27H46O; IUPAC systematic name; CAS 57-88-5.
Cholesterol Chemical Structure — Sterol, 2D Skeletal Formula, C27H46O, CAS 57-88-5

Weight

~386.65 g/mol

Chemical Formula

C₂₇H₄₆O

Synonyms

Cholest-5-en-3β-ol; 3β-hydroxycholest-5-ene; Cholesterin

External IDs

CAS: 57-88-5; PubChem CID: 5997; UNII: 97C5T2UQ7J


2. Pharmacology

Indication

Not an approved therapeutic active; roles as nutrient/excipient, and as a structural component in research lipid nanoparticles/liposomes.

Associated Conditions

Atherosclerotic cardiovascular disease risk relates to LDL-cholesterol burden; cholestasis and malabsorption affect sterol handling.

Associated Therapies

Targeted by statins (HMG-CoA reductase inhibitors), ezetimibe (NPC1L1 inhibitor), PCSK9 inhibitors (↑ LDLR recycling), bile-acid sequestrants, bempedoic acid, fibrates (indirect effects).

Contraindications & Blackbox Warnings

None (molecule is endogenous; safety considerations pertain to dyslipidemia management rather than exogenous cholesterol per se).

Pharmacodynamics

Modulates membrane order and permeability; regulates SREBP2 feedback; substrates for LCAT (plasma esterification) and ACAT/SOAT (intracellular esterification).

Mechanism of action

Endogenous: integrates into phospholipid bilayers; serves as precursor for bile acids (CYP7A1 pathway) and steroidogenesis; governs lipoprotein assembly/clearance via LDLR–ApoB/ApoE interactions.

Absorption

Dietary sterol uptake via NPC1L1 in enterocytes; competition with plant sterols; packaged into chylomicrons.

Volume of distribution

Distributed across membranes and lipoproteins; major pools in hepatobiliary system, enterocytes, and tissues.

Protein binding

Carried predominantly within lipoprotein particles (ApoB/ApoA-I platforms), not classical plasma protein binding.

Metabolism

De novo synthesis via mevalonate pathway (HMG-CoA reductase rate-limiting); esterification by ACAT/LCAT; conversion to bile acids in liver.

Route of elimination

Fecal elimination as bile acids and neutral sterols; minimal urinary excretion.

Half-life

Pool- and compartment-dependent; turnover governed by synthesis, conversion to bile acids, and fecal loss.

Clearance

Physiologic clearance through hepatic uptake (LDLR), biliary secretion (ABCG5/ABCG8), and fecal excretion.

Adverse Effects

Not applicable to the molecule itself; pathologic elevation of atherogenic lipoproteins drives ASCVD risk.

Toxicity

No conventional overdose context for endogenous cholesterol; toxicology pertains to lipoprotein-mediated vascular disease.

Pathways

Mevalonate (cholesterol) biosynthesis, bile acid synthesis, reverse cholesterol transport (HDL–SR-B1), esterification (LCAT/ACAT), intestinal NPC1L1 uptake, hepatic LDLR clearance.

Pharmacogenomic Effects/ADRs

Variants in LDLR, PCSK9, APOB, APOE, ABCG5/8, NPC1L1 influence cholesterol levels and therapeutic response.


3. Interactions

Drug Interactions

Not applicable as a therapeutic active; interactions concern lipid-lowering drugs acting on cholesterol pathways.

Food Interactions

Dietary cholesterol competes with phytosterols; overall impact on serum LDL-C is smaller than that of saturated/trans-fat intake.


4. Categories

ATC Codes

None assigned (not a drug active).

Drug Categories

Endogenous sterol; Excipient; Biomolecule

Chemical Taxonomy

Sterol (cholestanoid); tetracyclic cyclopenta[a]phenanthrene nucleus with Δ⁵ double bond; 3β-hydroxy substituent; isooctyl side chain.

Affected organisms

Humans and other animals


5. Chemical Identifiers

UNII

97C5T2UQ7J

CAS number

57-88-5

InChI Key

HVYWMOMLDIMFJA-DPAQBDIFSA-N

InChI

InChI=1S/C27H46O/c1-18(2)7-6-8-19(3)23-11-12-24-22-10-9-20-17-21(28)13-15-26(20,4)25(22)14-16-27(23,24)5/h9,18-19,21-25,28H,6-8,10-17H2,1-5H3/t19-,21+,22+,23-,24+,25+,26+,27-/m1/s1

IUPAC Name

(1R,3aS,3bS,7S,9aR,9bS,11aR)-9a,11a-dimethyl-1-[(2R)-6-methylheptan-2-yl]-1H,2H,3H,3aH,3bH,4H,6H,7H,8H,9H,9aH,9bH,10H,11H,11aH-cyclopenta[a]phenanthren-7-ol

SMILES

CC(C)CCCC(C)C1CCC2C3C(CC=C4C(C)(CCC(O)C24)C)C3CC1


6. References

PubChem Compound Summary: Cholesterol (CID 5997) — formula C₂₇H₄₆O, MW ~386.65, identifiers (InChI/InChIKey, SMILES). PubChem+1
CAS Common Chemistry — CAS RN 57-88-5, molecular formula, mass. Common Chemistry
FDA GSRS/UNII — Cholesterol UNII 97C5T2UQ7J entries in labeling databases. DailyMed+1
IUPAC/IARC Exposome-Explorer — IUPAC systematic name confirmation. Exposome Explorer
IUPHAR/BPS Guide to Pharmacology — ligand page (cholesterol; PDB ligand CLR; cross-references). IUPHAR/BPS Guide to Pharmacology
WHO/physiology texts — pathways: mevalonate biosynthesis, bile acid synthesis, lipoprotein transport; intestinal NPC1L1, hepatic LDLR, ABCG5/8 roles. Wikipedia

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