ContaminantDB: Pentobarbital

Identification Taxonomy Biological Properties Physical Properties Toxicity Profile Spectra Concentrations Links References Targets (32)XML

Record Information

Version

1.0

Creation Date

2009-07-21 20:26:33 UTC

Update Date

2026-05-14 16:25:20 UTC

Accession Number

CHEM002166

Identification

Common Name

Pentobarbital

Class

Small Molecule

Description

A short-acting barbiturate that is effective as a sedative and hypnotic (but not as an anti-anxiety) agent and is usually given orally. It is prescribed more frequently for sleep induction than for sedation but, like similar agents, may lose its effectiveness by the second week of continued administration. (From AMA Drug Evaluations Annual, 1994, p236)

Contaminant Sources

HMDB Contaminants - Urine
STOFF IDENT Compounds
Suspected Compounds
T3DB toxins
ToxCast & Tox21 Chemicals

Contaminant Type

Adjuvant, Anesthesia
Amide
Amine
Barbiturate
Drug
GABA Modulator
Hypnotic and Sedative
Metabolite
Organic Compound
Synthetic Compound

Chemical Structure

MOL SDF PDB SMILES InChI

Synonyms

Value	Source
5-Ethyl-5-(1-methyl-butyl)-pyrimidine-2,4,6-trione	ChEBI
5-Ethyl-5-(1-methylbutyl)-2,4,6(1H,3H,5H)-pyrimidinetrione	ChEBI
5-Ethyl-5-(1-methylbutyl)barbituric acid	ChEBI
5-Ethyl-5-(sec-pentyl)barbituric acid	ChEBI
Nembutal	ChEBI
Pentobarbitone	ChEBI
5-Ethyl-5-(1-methylbutyl)barbitate	Generator
5-Ethyl-5-(1-methylbutyl)barbitic acid	Generator
5-Ethyl-5-(sec-pentyl)barbitate	Generator
5-Ethyl-5-(sec-pentyl)barbitic acid	Generator
Pentabarbital	HMDB
Pentabarbitone	HMDB
Pentobarbiturate	HMDB
Pentobarbituric acid	HMDB
Sodium pentobarbital	HMDB
Etaminal	MeSH, HMDB
Ethaminal	MeSH, HMDB
Pentobarbital sodium	MeSH, HMDB
Sagatal	MeSH, HMDB
Diabutal	MeSH, HMDB
Pentobarbital, monosodium salt	MeSH, HMDB
Mebubarbital	MeSH, HMDB
Mebumal	MeSH, HMDB
Monosodium salt pentobarbital	MeSH, HMDB

Chemical Formula

C₁₁H₁₈N₂O₃

Average Molecular Mass

226.272 g/mol

Monoisotopic Mass

226.132 g/mol

CAS Registry Number

76-74-4

IUPAC Name

5-ethyl-5-(pentan-2-yl)-1,3-diazinane-2,4,6-trione

Traditional Name

pentobarbital

SMILES

CCCC(C)C1(CC)C(=O)NC(=O)NC1=O

InChI Identifier

InChI=1S/C11H18N2O3/c1-4-6-7(3)11(5-2)8(14)12-10(16)13-9(11)15/h7H,4-6H2,1-3H3,(H2,12,13,14,15,16)

InChI Key

WEXRUCMBJFQVBZ-UHFFFAOYSA-N

Chemical Taxonomy

Description

belongs to the class of organic compounds known as pyrimidones. Pyrimidones are compounds that contain a pyrimidine ring, which bears a ketone. Pyrimidine is a 6-membered ring consisting of four carbon atoms and two nitrogen centers at the 1- and 3- ring positions.

Kingdom

Organic compounds

Super Class

Organoheterocyclic compounds

Class

Diazines

Sub Class

Pyrimidines and pyrimidine derivatives

Direct Parent

Pyrimidones

Alternative Parents

Substituents

Pyrimidone
Hydropyrimidine
2,5-dihydropyrimidine
Carbonic acid derivative
Propargyl-type 1,3-dipolar organic compound
Organic 1,3-dipolar compound
Azacycle
Organic oxide
Organooxygen compound
Organonitrogen compound
Organopnictogen compound
Organic oxygen compound
Carbonyl group
Organic nitrogen compound
Hydrocarbon derivative
Aliphatic heteromonocyclic compound

Molecular Framework

Aliphatic heteromonocyclic compounds

External Descriptors

barbiturates (CHEBI:7983 )

Biological Properties

Status

Detected and Not Quantified

Origin

Exogenous

Cellular Locations

Membrane

Biofluid Locations

Not Available

Tissue Locations

Not Available

Pathways

Not Available

Applications

Not Available

Biological Roles

Not Available

Chemical Roles

Not Available

Physical Properties

State

Solid

Appearance

White powder.

Experimental Properties

Property	Value
Melting Point	129.5°C
Boiling Point	Not Available
Solubility	679 mg/L (at 25°C)

Predicted Properties

Property	Value	Source
Water Solubility	0.86 g/L	ALOGPS
logP	2.16	ALOGPS
logP	1.89	ChemAxon
logS	-2.4	ALOGPS
pKa (Strongest Acidic)	8.48	ChemAxon
Physiological Charge	0	ChemAxon
Hydrogen Acceptor Count	3	ChemAxon
Hydrogen Donor Count	2	ChemAxon
Polar Surface Area	75.27 Å²	ChemAxon
Rotatable Bond Count	4	ChemAxon
Refractivity	58 m³·mol⁻¹	ChemAxon
Polarizability	23.41 Å³	ChemAxon
Number of Rings	1	ChemAxon
Bioavailability	1	ChemAxon
Rule of Five	Yes	ChemAxon
Ghose Filter	Yes	ChemAxon
Veber's Rule	No	ChemAxon
MDDR-like Rule	No	ChemAxon

Spectra

Spectrum Type	Description	Splash Key	View
GC-MS	GC-MS Spectrum - CI-B (Non-derivatized)	splash10-004i-0090000000-0f97406e79f836abc074	Spectrum
GC-MS	GC-MS Spectrum - EI-B (Non-derivatized)	splash10-0a4l-5900000000-08245bcc95f52792c863	Spectrum
GC-MS	GC-MS Spectrum - CI-B (Non-derivatized)	splash10-004i-0090000000-0f97406e79f836abc074	Spectrum
GC-MS	GC-MS Spectrum - EI-B (Non-derivatized)	splash10-0a4l-5900000000-08245bcc95f52792c863	Spectrum
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	splash10-01xy-9720000000-ebfd954ba228514ca347	Spectrum
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	Not Available	Spectrum
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	Not Available	Spectrum
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	Not Available	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Positive	splash10-004i-1290000000-90bfbd79bea4fe2b007b	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Positive	splash10-0bti-1900000000-7e31dcdb272669c13101	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Positive	splash10-01bc-9100000000-c9fe8276b8137dc73d20	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Negative	splash10-004i-3980000000-84ea889a0fae4bed224b	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Negative	splash10-0006-9500000000-c226fe2dfb4ee13e4ae8	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Negative	splash10-000x-9500000000-cd4190b9c110ee5e4428	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Positive	splash10-0a4i-0930000000-ce337224a05a5827ddf4	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Positive	splash10-0a4i-1910000000-61c3bd30210f2bd15034	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Positive	splash10-0aos-6900000000-cd89b663334e7901acd1	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Negative	splash10-004i-1390000000-b300ae41f3e7623fa882	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Negative	splash10-0006-9000000000-b2af88d76179b3402570	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Negative	splash10-0006-9300000000-99ecf1568fa04b732c33	Spectrum
MS	Mass Spectrum (Electron Ionization)	splash10-0a4l-6900000000-a65d8c67e006ad448814	Spectrum

Toxicity Profile

Route of Exposure

Barbiturates are absorbed in varying degrees following intravenous, oral, rectal, or parenteral administration.

Mechanism of Toxicity

Pentobarbital binds at a distinct binding site associated with a Cl- ionopore at the GABAA receptor, increasing the duration of time for which the Cl- ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged. All of these effects are associated with marked decreases in GABA-sensitive neuronal calcium conductance (gCa). The net result of barbiturate action is acute potentiation of inhibitory GABAergic tone. Barbiturates also act through potent (if less well characterized) and direct inhibition of excitatory AMPA-type glutamate receptors, resulting in a profound suppression of glutamatergic neurotransmission.

Metabolism

By hepatic microsomal enzyme system. Route of Elimination: Barbiturates are metabolized primarily by the hepatic microsomal enzyme system, and the metabolic products are excreted in the urine, and less commonly, in the feces. Approximately 25 to 50 percent of a dose of aprobarbital or phenobarbital is eliminated unchanged in the urine, whereas the amount of other barbiturates excreted unchanged in the urine is negligible. Half Life: 5 to 50 hours (dose dependent)

Toxicity Values

Not Available

Lethal Dose

Not Available

Carcinogenicity (IARC Classification)

No indication of carcinogenicity to humans (not listed by IARC).

Uses/Sources

For the short-term treatment of insomnia.

Minimum Risk Level

Not Available

Health Effects

They cause slurred speech, disorientation and "drunken" behavior. They are physically and psychologically addictive. They cause slurred speech, disorientation and "drunken" behavior. They are physically and psychologically addictive.

Symptoms

Symptoms of an overdose typically include sluggishness, incoordination, difficulty in thinking, slowness of speech, faulty judgment, drowsiness or coma, shallow breathing, staggering, and in severe cases coma and death.

Treatment

Treatment of overdosage is mainly supportive and consists of maintaining an adequate airway, with assisted respiration and oxygen administration as necessary, monitoring of vital signs and fluid balance, and fluid therapy and other standard treatment for shock, if needed. If renal function is normal, forced diuresis may aid in the elimination of the barbiturate. Alkalinization of the urine increases renal excretion of some barbiturates, especially phenobarbital, also aprobarbital and mephobarbital (which is metabolized to phenobarbital). Although not recommended as a routine procedure, hemodialysis may be used in severe barbiturate intoxications or if the patient is anuric or in shock. The patient should be rolled from side to side every 30 minutes and antibiotics should be given if pneumonia is suspected. Appropriate nursing care to prevent hypostatic pneumonia, decubiti, aspiration, and other complications of patients with altered states of consciousness. (3)

Concentrations

Not Available

External Links

DrugBank ID

DB00312

HMDB ID

HMDB0259667

FooDB ID

Not Available

Phenol Explorer ID

Not Available

KNApSAcK ID