Title: Droxidopa
CAS Registry Number: 23651-95-8
CAS Name: threo-b,3-Dihydroxy-L-tyrosine
Additional Names: L-threo-3-(3,4-dihydroxyphenyl)serine; (-)-(2S,3R)-2-amino-3-hydroxy-3-(3,4-dihydroxyphenyl)propionic acid; threo-dopaserine; L-threo-DOPS; L-DOPS
Manufacturers' Codes: SM-5688
Trademarks: Dops (Sumitomo)
Molecular Formula: C9H11NO5
Molecular Weight: 213.19
Percent Composition: C 50.70%, H 5.20%, N 6.57%, O 37.52%
Literature References: Synthetic amino acid precursor of norepinephrine, q.v. Prepn of racemate: K. W. Rosenmund, H. Dornsaft, Ber. 52B, 1734 (1919). Separation and resolution of diastereomers: B. Hegedüs et al., Helv. Chim. Acta 58, 147 (1975); B. Hegedüs, A. Krasso, US 3920728 (1975 to Hoffmann-La Roche). Improved process for production: N. Ohashi et al., US 4319040 (1982 to Sumitomo). Pharmacology of stereoisomers: G. Bartholini et al., J. Pharmacol. Exp. Ther. 193, 523 (1975). Clinical pharmacology of L-threo-form and clinical evaluation in familial amyloid polyneuropathy (FAP): T. Suzuki et al., Eur. J. Clin. Pharmacol. 17, 429 (1980). Reversed-phase chromatography determn in plasma and urine: F. Boomsma et al., J. Chromatogr. 427, 219 (1988). Pharmacokinetics in FAP: T. Suzuki et al., Eur. J. Clin. Pharmacol. 23, 463 (1982); in parkinsonism: T. Suzuki et al., Neurology 34, 1446 (1984). Metabolism to norepinephrine: T. Suzuki et al., Life Sci. 36, 435 (1985). Clinical studies in Parkinson's disease: N. Ogawa et al., J. Med. 16, 525 (1985); H. Narabayashi et al., Adv. Neurol. 45, 593 (1986).
Properties: Crystals from ethanol and ether, mp 232-235° (dec). [a]D20 -39° (c = 1 in 1N aq HCl). Also cited as crystals from water and L-ascorbic acid, mp 229-232° (dec) (Ohashi). [a]D20 -42.0° (c = 1 in 1N aq HCl).
Melting point: mp 232-235° (dec); mp 229-232° (dec) (Ohashi)
Optical Rotation: [a]D20 -39° (c = 1 in 1N aq HCl); [a]D20 -42.0° (c = 1 in 1N aq HCl)
Therap-Cat: Antiparkinsonian.
Keywords: Antiparkinsonian.
DSPA DTAF D-Tagatose D-Tartaric Acid DTBP

Systematic (IUPAC) name
(2R,3S)-2-Amino-3-(3,4-dihydroxyphenyl)-3-hydroxypropanoic acid
Clinical data
Trade names Northera
Legal status Prescription only
Routes Oral
Pharmacokinetic data
Bioavailability 90%
Metabolism hepatic
Half-life 1.5 hours
Excretion renal
CAS number 23651-95-8 YesY
ATC code None
PubChem CID 3171
UNII J7A92W69L7 YesY
Synonyms β,3-Dihydroxytyrosine
Chemical data
Formula C9H11NO5 
Mol. mass 213.18734 g/mol
 YesY (what is this?)  (verify)

Droxidopa (INN; trade name Northera; also known as L-DOPS, L-threo-dihydroxyphenylserine, and SM-5688) is a synthetic amino acid precursor which acts as a prodrug to the neurotransmitters norepinephrine (noradrenaline) and epinephrine (adrenaline).[1] Unlike norepinephrine and epinephrine themselves, droxidopa is capable of crossing the protective blood–brain barrier (BBB).[1]