Benzene chemical structure, aromatic ring, 2D skeletal formula, C6H6

Benzene Chemical Structure

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1. Identification

Summary

Benzene is an aromatic hydrocarbon (C₆H₆) consisting of a planar six-membered ring with delocalized π electrons; a foundational motif (“phenyl”) in organic chemistry and an industrial solvent/intermediate.

Brand Names

Not applicable.

Name

Benzene

Background

Endogenous to crude oil and combustion streams; widely used as a chemical feedstock; environmental and occupational toxicant with established leukemogenic potential.

Modality

Small molecule

Groups

Industrial chemical; environmental toxicant

Structure

Benzene chemical structure, aromatic ring, 2D skeletal formula, C6H6
Benzene 2D chemical structure (planar aromatic ring). Formula C6H6; IUPAC name Benzene; CAS 71-43-2.

Weight

~78.11 g/mol

Chemical Formula

C₆H₆

Synonyms

Benzol; Cyclohexa-1,3,5-triene (historic); Phene

External IDs

CAS: 71-43-2; PubChem CID: 241; UNII: J64922108F

2. Pharmacology

Indication

Not a therapeutic agent.

Associated Conditions

Occupational/environmental exposure linked to bone-marrow toxicity and hematologic malignancy risk.

Associated Therapies

Not applicable.

Contraindications & Blackbox Warnings

Not applicable (non-drug); regulatory guidance treats benzene as a known human carcinogen with strict exposure limits.

Pharmacodynamics

Central nervous system depressant at high acute doses; chronic exposure damages hematopoietic stem/progenitor cells.

Mechanism of action

Metabolic activation (e.g., phenolic/epoxide metabolites) generates reactive species that impair DNA, proteins, and marrow stromal signaling.

Absorption

Inhalational absorption predominant; dermal and oral uptake occur with liquid contact or contaminated water/foods.

Volume of distribution

Distributes into lipid-rich tissues; volatile, rapidly partitions to blood–air interface.

Protein binding

Reversible binding to plasma lipoproteins and tissue lipids; limited specific protein binding.

Metabolism

Primarily hepatic oxidative metabolism to phenol, catechol, hydroquinone, and ring-opened species; further conjugation (glucuronidation/sulfation).

Route of elimination

Pulmonary exhalation of parent; urinary excretion of conjugated metabolites.

Half-life

Short for parent compound (hours); metabolite kinetics depend on dose and route.

Clearance

Combination of pulmonary exhalation and hepatic biotransformation followed by renal elimination.

Adverse Effects

Acute: dizziness, headache, CNS depression, arrhythmia at very high levels.
Chronic: leukopenia, anemia, thrombocytopenia; increased leukemia risk.

Toxicity

High-level exposure: narcosis, ventricular dysrhythmias, death. Chronic low-level exposure: cumulative marrow injury with latency to malignancy.

Pathways

Phase I oxidation (CYP2E1-dominant) → phenolic/epoxide metabolites → Phase II conjugation; marrow redox stress and DNA damage responses.

Pharmacogenomic Effects/ADRs

Interindividual variability in CYP2E1/Phase II enzymes modifies metabolite burden; co-exposures (e.g., alcohol, toluene) alter activation.

3. Interactions

Drug Interactions

Not applicable as a medicine; solvent co-exposures and enzyme inducers/inhibitors can modify benzene metabolism/toxicity.

Food Interactions

Not applicable; ingestion concerns relate to contamination, not intended intake.

4. Categories

ATC Codes

None.

Drug Categories

Not a drug; aromatic hydrocarbon; environmental toxicant

Chemical Taxonomy

Monocyclic arene; planar conjugated ring; delocalized π system

Affected organisms

Humans and other exposed organisms (toxicology context)

5. Chemical Identifiers

UNII

J64922108F

CAS number

71-43-2

InChI Key

UHOVQNZJYSORNB-UHFFFAOYSA-N

InChI

InChI=1S/C6H6/c1-2-4-6-5-3-1/h1-6H

IUPAC Name

Benzene

SMILES

c1ccccc1

6. References

PubChem Compound Summary: Benzene — formula C₆H₆, MW ~78.11, identifiers (CID 241), synonyms, structure. pubchem.ncbi.nlm.nih.gov
NIST Chemistry WebBook — IUPAC InChI InChI=1S/C6H6/c1-2-4-6-5-3-1/h1-6H and InChIKey UHOVQNZJYSORNB-UHFFFAOYSA-N; CAS 71-43-2. NIST WebBook+1
FDA GSRS/UNII — Benzene UNII J64922108F public record. precision.fda.gov
EPA IRIS — Benzene carcinogenicity and risk assessment overview. iris.epa.gov
FDA communications — benzene as known human carcinogen; contamination advisories for drug products. U.S. Food and Drug Administration+1

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