Compound

cysteamine

A mercaptoethylamine compound that is endogenously derived from the coenzyme A degradative pathway. The fact that cysteamine is readily transported into lysosomes where it reacts with cystine to form cysteine-cysteamine disulfide and cysteine has led to its use in cystine depleting agents for the treatment of cystinosis.

Definition from MeSH (D003543), National Library of Medicine, read 2026-09-23. NLM revises MeSH; this copy may not reflect its current record.

CHEBI:58029ChEBI

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Structure

2D depiction · 3D model shown

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A generated conformer of cysteamine — one low-energy arrangement PubChem computed, not a measured structure. Hydrogens are not drawn; the formula counts them.

Class: Organic compound, cation
Formula: C2H8NS
Mass: 78.16 g/mol
Charge: +1
InChIKey: UFULAYFCSOUIOV-UHFFFAOYSA-O
SMILES: [NH3+]CCS
Look it up: ChEBI PubChem By InChIKey

Identity from ChEBI, geometry from PubChem. Not evidence.

What it touches on the way

Mechanistic reach

3 entities

3 entities reached.

0 reported hops3 assembled from the scaffold

What the reference databases state

Regulatory determinations

LiverTox likelihood score D [HD]LiverTox
LiverTox Likelihood Score D [HD] — a possible hepatotoxin, single-to-few case reports. Hepatotoxic at overdose specifically, not at recommended use. Chapter: "Cysteamine". Source: LiverTox Master List (NBK571102).
The document·Public Domain (NLM/NIH)·Transcribed, not graded

Statements

10 statements

10 statements · 2 reference databases · Subject: cysteamine · Sources: Human-GEM, Rhea

Order

cysteamine is converted to CHEBI:16668CompoundHuman-GEM MAR04679Inferred only
cysteamine is converted to CHEBI:16668CompoundHuman-GEM MAR07817Inferred only
cysteamine is converted to hypotaurineCompoundRhea RHEA:14409Inferred only
hypotaurine is converted to cysteamineCompoundRhea RHEA:14409Inferred only
cysteamine is a substrate of ADOProteinHuman-GEM MAR04679Inferred only
cysteamine is a substrate of ADOProteinRhea RHEA:14409Inferred only
cysteamine is a substrate of VNN1ProteinHuman-GEM MAR04717Inferred only
cysteamine is a substrate of VNN1ProteinRhea RHEA:13445Inferred only
cysteamine is a substrate of VNN2ProteinRhea RHEA:13445Inferred only
cysteamine is a substrate of VNN2ProteinHuman-GEM MAR04717Inferred only

Reactions

10 reactions

cysteamine+dioxygenproton+CHEBI:16668
Catalysed by ADO
Reaction pageLeft to rightBalancedEC 1.13.11.19GO:0005829
Human-GEM MAR04679CC BY 4.0Reference data
water+(R)-pantetheinecysteamine+pantothenic acid
Catalysed by VNN1 or VNN2
Reaction pageReversibleBalancedEC 3.5.1.92GO:0005829
Human-GEM MAR04717CC BY 4.0Reference data
cysteamine+dioxygenproton+CHEBI:16668
Reaction pageLeft to rightBalancedGO:0005615
Human-GEM MAR07817CC BY 4.0Reference data
cysteamine
Reaction pageReversibleBalance undeterminableGO:0005615
Human-GEM MAR08960CC BY 4.0Reference data
water+(R)-pantetheinecysteamine+pantothenic acid
Reaction pageLeft to rightBalancedGO:0005615
Human-GEM MAR08986CC BY 4.0Reference data
(R)-pantetheine+watercysteamine+(R)-pantothenate
Catalysed by VNN1 or VNN2
Reaction pageLeft to rightBalance undeterminable
Rhea RHEA:13445CC BY 4.0Reference data
cysteamine+dioxygenhypotaurine+hydron
Catalysed by ADO
Reaction pageLeft to rightBalance undeterminable
Rhea RHEA:14409CC BY 4.0Reference data
cysteamine+acetyl-CoACHEBI:58295+coenzyme A(4-)
Reaction pageDirection not assertedBalance undeterminable
Rhea RHEA:23280CC BY 4.0Reference data
L-cysteine+hydroncysteamine+carbon dioxide
Reaction pageDirection not assertedBalance undeterminable
Rhea RHEA:27746CC BY 4.0Reference data
CHEBI:74631+watercysteamine+hydrogenphosphate
Reaction pageDirection not assertedBalance undeterminable
Rhea RHEA:37251CC BY 4.0Reference data

Other names

7 names

Resolves to: cysteamine

Also called: 2-ammonioethanethiol2-sulfanylethan-1-aminiumbeta-ammonioethylthiolcysteaminium cationcysteaminium(1+)β-ammonioethylthiol
Systematic name: 2-sulfanylethanaminium