ContaminantDB: Methyldopa

Identification Taxonomy Biological Properties Physical Properties Toxicity Profile Spectra Concentrations Links References Targets (4)XML

Record Information

Version

1.0

Creation Date

2009-07-30 17:58:37 UTC

Update Date

2026-04-13 20:39:34 UTC

Accession Number

CHEM002504

Identification

Common Name

Methyldopa

Class

Small Molecule

Description

Methyldopa or alpha-methyldopa (brand names Aldomet, Apo-Methyldopa, Dopamet, Novomedopa) is a centrally-acting adrenergic antihypertensive medication. Its use is now deprecated following introduction of alternative safer classes of agents. However it continues to have a role in otherwise difficult to treat hypertension and gestational hypertension (formerly known as pregnancy-induced hypertension). Methyldopa is an aromatic-amino-acid decarboxylase inhibitor in animals and in man. Only methyldopa, the L-isomer of alpha-methyldopa, has the ability to inhibit dopa decarboxylase and to deplete animal tissues of norepinephrine. In man the antihypertensive activity appears to be due solely to the L-isomer. About twice the dose of the racemate (DL-alpha-methyldopa) is required for equal antihypertensive effect. Methyldopa has no direct effect on cardiac function and usually does not reduce glomerular filtration rate, renal blood flow, or filtration fraction. Cardiac output usually is maintained without cardiac acceleration. In some patients the heart rate is slowed. Normal or elevated plasma renin activity may decrease in the course of methyldopa therapy. Methyldopa reduces both supine and standing blood pressure. Methyldopa usually produces highly effective lowering of the supine pressure with infrequent symptomatic postural hypotension. Exercise hypotension and diurnal blood pressure variations rarely occur. Methyldopa, in its active metabolite form, is a central alpha-2 receptor agonist. Using methyldopa leads to alpha-2 receptor-negative feedback to sympathetic nervous system (SNS) (centrally and peripherally), allowing peripheral sympathetic nervous system tone to decrease. Such activity leads to a decrease in total peripheral resistance (TPR) and cardiac output. When introduced it was a mainstay of antihypertensive therapy, but its use has declined, with increased use of other safer classes of agents. One of its important present-day uses is in the management of pregnancy-induced hypertension, as it is relatively safe in pregnancy compared to other antihypertensive drugs (Wikipedia).

Contaminant Sources

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

Contaminant Type

Adrenergic alpha-2 Receptor Agonist
Adrenergic alpha-Agonist
Amine
Antihypertensive Agent
Drug
Food Toxin
Metabolite
Organic Compound
Sympatholytic
Synthetic Compound

Chemical Structure

MOL SDF PDB SMILES InChI

Synonyms

Value	Source
(2S)-2-Amino-3-(3,4-dihydroxyphenyl)-2-methylpropanoic acid	ChEBI
(S)-(-)-alpha-Methyldopa	ChEBI
3-Hydroxy-alpha-methyl-L-tyrosine	ChEBI
Alpha Medopa	ChEBI
alpha-Methyl dopa	ChEBI
alpha-Methyl-beta-(3,4-dihydroxyphenyl)-L-alanine	ChEBI
alpha-Methyl-L-3,4-dihydroxyphenylalanine	ChEBI
alpha-Methyldihydroxyphenylalanine	ChEBI
alpha-Methyldopa	ChEBI
Alphamethyldopa	ChEBI
AMD	ChEBI
L(-)-beta-(3,4-Dihydroxyphenyl)-alpha-methylalanine	ChEBI
L-(-)-3-(3,4-Dihydroxyphenyl)-2-methylalanine	ChEBI
L-(-)-alpha-Methyl-beta-(3,4-dihydroxyphenyl)alanine	ChEBI
L-(alpha-MD)	ChEBI
L-2-Amino-2-methyl-3-(3,4-dihydroxyphenyl)propionic acid	ChEBI
L-3-(3,4-Dihydroxyphenyl)-2-methylalanine	ChEBI
L-alpha-Methyl-3,4-dihydroxyphenylalanine	ChEBI
L-alpha-Methyldopa	ChEBI
L-Methyl dopa	ChEBI
Levo-3-(3,4-dihydroxyphenyl)-2-methylalanine	ChEBI
Methyl-L-dopa	ChEBI
Methyldopa anhydrous	ChEBI
Methyldopum	ChEBI
Metildopa	ChEBI
Aldomet	Kegg
(2S)-2-Amino-3-(3,4-dihydroxyphenyl)-2-methylpropanoate	Generator
(S)-(-)-a-Methyldopa	Generator
(S)-(-)-Α-methyldopa	Generator
3-Hydroxy-a-methyl-L-tyrosine	Generator
3-Hydroxy-α-methyl-L-tyrosine	Generator
a Medopa	Generator
Α medopa	Generator
a-Methyl dopa	Generator
Α-methyl dopa	Generator
a-Methyl-b-(3,4-dihydroxyphenyl)-L-alanine	Generator
Α-methyl-β-(3,4-dihydroxyphenyl)-L-alanine	Generator
a-Methyl-L-3,4-dihydroxyphenylalanine	Generator
Α-methyl-L-3,4-dihydroxyphenylalanine	Generator
a-Methyldihydroxyphenylalanine	Generator
Α-methyldihydroxyphenylalanine	Generator
a-Methyldopa	Generator
Α-methyldopa	Generator
L(-)-b-(3,4-Dihydroxyphenyl)-a-methylalanine	Generator
L(-)-Β-(3,4-dihydroxyphenyl)-α-methylalanine	Generator
L-(-)-a-Methyl-b-(3,4-dihydroxyphenyl)alanine	Generator
L-(-)-Α-methyl-β-(3,4-dihydroxyphenyl)alanine	Generator
L-(a-MD)	Generator
L-(Α-MD)	Generator
L-2-Amino-2-methyl-3-(3,4-dihydroxyphenyl)propionate	Generator
L-a-Methyl-3,4-dihydroxyphenylalanine	Generator
L-Α-methyl-3,4-dihydroxyphenylalanine	Generator
L-a-Methyldopa	Generator
L-Α-methyldopa	Generator
(-)-a-Methyldopa	HMDB
(-)-alpha-Methyldopa	HMDB
(-)-Methyldopa	HMDB
2-Methyl-3-(3,4-dihydroxyphenyl)alanine	HMDB
3,4-Dihydroxy-2-methylphenylalanine (acd/name 4.0)	HMDB
a-Methyl-L-dopa	HMDB, Generator
Aldoclor-150	HMDB
Aldoclor-250	HMDB
Aldometil	HMDB
Aldoril 15	HMDB
Aldoril 25	HMDB
Aldoril D30	HMDB
Aldoril D50	HMDB
alpha-Methyl-L-dopa	HMDB, MeSH
apo Methyldopa tab 125MG	HMDB
apo Methyldopa tab 250MG	HMDB
apo Methyldopa tab 500MG	HMDB
apo-Methyldopa	HMDB, MeSH
Bayer 1440 L	HMDB
Baypresol	HMDB
Becanta	HMDB
Dopamet	HMDB, MeSH
Dopamethyperpax	HMDB
Dopatec	HMDB
Dopegyt	HMDB, MeSH
Grospisk	HMDB
Hyperpax	HMDB
Hypolag	HMDB
L(-)-a-Methylalanine	HMDB
L(-)-alpha-Methylalanine	HMDB
L-(-)-3-(3,4-Dihydroxyphenyl)-2-methyl-alanine	HMDB
L-(-)-a-Methyl-a-methyl-aldomin	HMDB
L-(-)-alpha-Methyl-alpha-methyl-aldomin	HMDB
L-a-Methyl-(3, 4-dihydroxyphenyl)alanine	HMDB
L-alpha-Methyl-(3, 4-dihydroxyphenyl)alanine	HMDB
Medomet	HMDB
Medopa	HMDB
Medopal	HMDB
Medopren	HMDB
Methoplain	HMDB
Methyldopa 125 tab 125MG	HMDB
Methyldopa 250 tab	HMDB
Methyldopa 500 tab 500MG	HMDB
Methyldopate	HMDB, MeSH
Methyldopate HCL	HMDB
novo-Medopa tab 125MG	HMDB
novo-Medopa tab 250MG	HMDB
novo-Medopa tab 500MG	HMDB
Novomedopa	HMDB
Nu-medopa	HMDB, MeSH
Nu-medopa tab 125MG	HMDB
Nu-medopa tab 250MG	HMDB
Nu-medopa tab 500MG	HMDB
Presinol	HMDB
Presolisin	HMDB
Sedometil	HMDB
Sembrina	HMDB, MeSH
Alphapharm brand OF methyldopa	MeSH, HMDB
Apotex brand OF methyldopa	MeSH, HMDB
Merck brand OF methyldopa	MeSH, HMDB
Nu pharm brand OF methyldopa	MeSH, HMDB
Dopergit	MeSH, HMDB
Hydopa	MeSH, HMDB
Merck sharp and dohme brand OF methyldopa	MeSH, HMDB
Methyldopa orion brand	MeSH, HMDB
Nu-pharm brand OF methyldopa	MeSH, HMDB
Orion brand OF methyldopa	MeSH, HMDB
Rhône poulenc rorer brand OF methyldopa	MeSH, HMDB
Rhône-poulenc rorer brand OF methyldopa	MeSH, HMDB
Dopegit	MeSH, HMDB
Methyldopa apotex brand	MeSH, HMDB
Methyldopa biopat brand	MeSH, HMDB
Methyldopa clonmel brand	MeSH, HMDB
Methyldopa merck brand	MeSH, HMDB
Nu medopa	MeSH, HMDB
alpha Methyl L dopa	MeSH, HMDB
alpha Methyldopa	MeSH, HMDB
apo Methyldopa	MeSH, HMDB
Biopat brand OF methyldopa	MeSH, HMDB
Cahill may roberts brand OF methyldopa	MeSH, HMDB
Clonmel brand OF methyldopa	MeSH, HMDB
Meldopa	MeSH, HMDB
Methyldopa alphapharm brand	MeSH, HMDB
Methyldopa nu-pharm brand	MeSH, HMDB
Methyldopa	ChEBI
Α-methyl-L-dopa	Generator, HMDB

Chemical Formula

C₁₀H₁₃NO₄

Average Molecular Mass

211.215 g/mol

Monoisotopic Mass

211.084 g/mol

CAS Registry Number

555-29-3

IUPAC Name

(2S)-2-amino-3-(3,4-dihydroxyphenyl)-2-methylpropanoic acid

Traditional Name

methyldopa

SMILES

C[C@](N)(CC1=CC=C(O)C(O)=C1)C(O)=O

InChI Identifier

InChI=1S/C10H13NO4/c1-10(11,9(14)15)5-6-2-3-7(12)8(13)4-6/h2-4,12-13H,5,11H2,1H3,(H,14,15)/t10-/m0/s1

InChI Key

CJCSPKMFHVPWAR-JTQLQIEISA-N

Chemical Taxonomy

Description

belongs to the class of organic compounds known as phenylpropanoic acids. Phenylpropanoic acids are compounds with a structure containing a benzene ring conjugated to a propanoic acid.

Kingdom

Organic compounds

Super Class

Phenylpropanoids and polyketides

Class

Phenylpropanoic acids

Sub Class

Not Available

Direct Parent

Phenylpropanoic acids

Alternative Parents

Substituents

3-phenylpropanoic-acid
Alpha-amino acid
D-alpha-amino acid
Alpha-amino acid or derivatives
Amphetamine or derivatives
Phenylpropane
Catechol
1-hydroxy-2-unsubstituted benzenoid
Aralkylamine
1-hydroxy-4-unsubstituted benzenoid
Phenol
Monocyclic benzene moiety
Benzenoid
Amino acid
Amino acid or derivatives
Carboxylic acid derivative
Monocarboxylic acid or derivatives
Carboxylic acid
Organic nitrogen compound
Primary aliphatic amine
Organonitrogen compound
Organooxygen compound
Primary amine
Carbonyl group
Hydrocarbon derivative
Organic oxide
Organopnictogen compound
Amine
Organic oxygen compound
Aromatic homomonocyclic compound

Molecular Framework

Aromatic homomonocyclic compounds

External Descriptors

non-proteinogenic L-alpha-amino acid (CHEBI:61058 )
L-tyrosine derivative (CHEBI:61058 )

Biological Properties

Status

Detected and Not Quantified

Origin

Exogenous

Cellular Locations

Cytoplasm
Extracellular

Biofluid Locations

Not Available

Tissue Locations

Not Available

Pathways

Not Available

Applications

Biological Roles

Chemical Roles

Not Available

Physical Properties

State

Solid

Appearance

White powder.

Experimental Properties

Property	Value
Melting Point	300°C
Boiling Point	Not Available
Solubility	10mg/mL at 25°C

Predicted Properties

Property	Value	Source
Water Solubility	2.26 g/L	ALOGPS
logP	-2	ALOGPS
logP	-1.4	ChemAxon
logS	-2	ALOGPS
pKa (Strongest Acidic)	1.73	ChemAxon
pKa (Strongest Basic)	9.85	ChemAxon
Physiological Charge	0	ChemAxon
Hydrogen Acceptor Count	5	ChemAxon
Hydrogen Donor Count	4	ChemAxon
Polar Surface Area	103.78 Å²	ChemAxon
Rotatable Bond Count	3	ChemAxon
Refractivity	53.79 m³·mol⁻¹	ChemAxon
Polarizability	20.73 Å³	ChemAxon
Number of Rings	1	ChemAxon
Bioavailability	1	ChemAxon
Rule of Five	Yes	ChemAxon
Ghose Filter	No	ChemAxon
Veber's Rule	No	ChemAxon
MDDR-like Rule	No	ChemAxon

Spectra

Spectrum Type	Description	Splash Key	View
GC-MS	GC-MS Spectrum - GC-EI-TOF (Non-derivatized)	splash10-001i-0690000000-f54d986a8144f4a79b82	Spectrum
GC-MS	GC-MS Spectrum - GC-EI-TOF (Non-derivatized)	splash10-001i-0690000000-f54d986a8144f4a79b82	Spectrum
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	splash10-00xu-4900000000-739bef9b92ae61fa3997	Spectrum
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (3 TMS) - 70eV, Positive	splash10-03l3-6719300000-8507376d6ae27047f468	Spectrum
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	Not Available	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - LC-ESI-qTof , Positive	splash10-0g5i-2900000000-2d1c0ec9ad93e208b620	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - , positive	splash10-0g5i-2900000000-2d1c0ec9ad93e208b620	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 15V, Negative	splash10-01p2-3940000000-04fec0e15e79c768fdc7	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 30V, Negative	splash10-0002-2910000000-5ab87bad3301cc12d671	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 90V, Positive	splash10-0wmi-5900000000-8d84c2b3f8d906813668	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 75V, Positive	splash10-0ik9-2900000000-f0762b6c346fb34404e5	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 15V, Positive	splash10-014s-0910000000-ef3d681f544c504b6f07	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 30V, Positive	splash10-014r-0900000000-a11a3fc0536274091e7c	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 60V, Positive	splash10-03y0-0900000000-20bad18343ec957bca95	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 45V, Positive	splash10-014r-0900000000-2a78e6a20d8599caab2b	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 15V, Positive	splash10-014s-0910000000-db2e7c58eec2a2e9f25e	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 60V, Positive	splash10-03y0-0900000000-4ee772845ee32a944db1	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 60V, Positive	splash10-0002-1900000000-3efdf92a8af6e42965e2	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 60V, Negative	splash10-0002-1900000000-4ba9f4555cda937d3883	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 45V, Negative	splash10-006t-1900000000-aa6c8ce94351767534b1	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 75V, Negative	splash10-0002-0900000000-cdcf4d0d2fe21483aac5	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Positive	splash10-014i-0910000000-3bfdb36173438fdd8a17	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Positive	splash10-014i-0900000000-9b6b615025e3da8f5450	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Positive	splash10-0600-4900000000-34dc05f00879ecc053bf	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Positive	splash10-014i-0910000000-3bfdb36173438fdd8a17	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Positive	splash10-014i-0900000000-9b6b615025e3da8f5450	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Positive	splash10-0600-4900000000-34dc05f00879ecc053bf	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Negative	splash10-03di-4290000000-cdd2c737cabf0ee44d1f	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Negative	splash10-000i-9410000000-d1fa6c265dd8ca539a0e	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Negative	splash10-007d-6900000000-56bdd61262b97efe050b	Spectrum
1D NMR	1H NMR Spectrum	Not Available	Spectrum
1D NMR	13C NMR Spectrum	Not Available	Spectrum
1D NMR	1H NMR Spectrum	Not Available	Spectrum
1D NMR	13C NMR Spectrum	Not Available	Spectrum
1D NMR	1H NMR Spectrum	Not Available	Spectrum
1D NMR	13C NMR Spectrum	Not Available	Spectrum
1D NMR	1H NMR Spectrum	Not Available	Spectrum
1D NMR	13C NMR Spectrum	Not Available	Spectrum
1D NMR	1H NMR Spectrum	Not Available	Spectrum
1D NMR	13C NMR Spectrum	Not Available	Spectrum
1D NMR	1H NMR Spectrum	Not Available	Spectrum
1D NMR	13C NMR Spectrum	Not Available	Spectrum
1D NMR	1H NMR Spectrum	Not Available	Spectrum
1D NMR	13C NMR Spectrum	Not Available	Spectrum
1D NMR	1H NMR Spectrum	Not Available	Spectrum
1D NMR	13C NMR Spectrum	Not Available	Spectrum
1D NMR	1H NMR Spectrum	Not Available	Spectrum
1D NMR	13C NMR Spectrum	Not Available	Spectrum
1D NMR	1H NMR Spectrum	Not Available	Spectrum
1D NMR	13C NMR Spectrum	Not Available	Spectrum

Toxicity Profile

Route of Exposure

Oral

Mechanism of Toxicity

Although the mechanism of action has yet to be conclusively demonstrated, the antihypertensive effect of methyldopa probably is due to its metabolism to alpha-methylnorepinephrine, which then lowers arterial pressure by stimulation of central inhibitory alpha-adrenergic receptors, false neurotransmission, and/or reduction of plasma renin activity. Methyldopa has been shown to cause a net reduction in the tissue concentration of serotonin, dopamine, norepinephrine, and epinephrine.

Metabolism

Hepatic, extensively metabolized. The known urinary metabolites are: a-methyldopa mono-0-sulfate; 3-0-methyl-a-methyldopa; 3,4-dihydroxyphenylacetone; a-methyldopamine; 3-0-methyl-a-methyldopamine and their conjugates.

Toxicity Values

LD50: > 1.5 g/kg( oral, mouse) LD50: > 1.5 g/kg( oral, rat)

Lethal Dose

Not Available

Carcinogenicity (IARC Classification)

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

Uses/Sources

Not Available

Minimum Risk Level

Not Available

Health Effects

Not Available

Symptoms

Symptoms of overdose include bloating, constipation, diarrhea, dizziness, extreme drowsiness, gas, light-headedness, nausea, severely low blood pressure, slow heartbeat, vomiting, and weakness.

Treatment

Not Available

Concentrations

Not Available

External Links

DrugBank ID

DB00968

HMDB ID

HMDB0011754

FooDB ID

FDB028425

Phenol Explorer ID