{"id":532,"date":"2022-10-02T09:40:48","date_gmt":"2022-10-02T07:40:48","guid":{"rendered":"https:\/\/modafinil.pl\/sklep\/l-dopa-%e2%89%a5-99-pure-chemical-substance-without-fillers\/"},"modified":"2026-10-03T06:11:56","modified_gmt":"2026-10-03T04:11:56","slug":"l-dopa-2","status":"publish","type":"product","link":"https:\/\/modafinil.pl\/en\/sklep\/l-dopa-2\/","title":{"rendered":"L-DOPA \/ Levodopa (CAS 59-92-7) \u2014 laboratory reagent 1000 mg, purity \u2265 99%"},"content":{"rendered":"

(2S)-2-amino-3-(3,4-dihydroxyphenyl)propanoic acid<\/strong>, crystalline powder, 1000 mg pack. Material intended exclusively for laboratory and analytical in vitro research<\/strong>. The product is not intended for human or animal consumption<\/strong>; it is not a medicinal product, food supplement, foodstuff or cosmetic.<\/p>\n

Three distinct entities that must not be confused<\/h2>\n

For this molecule, separating the layers is particularly important, because the same chemical name stands both for one of the longest-used medicines in neurology and for the reagent sold on this page. Three contexts, three entirely different legal statuses:<\/p>\n\n\n\n\n\n\n\n
Separating the layers: substance \u2014 medicinal product \u2014 reagent<\/caption>\n
Entity<\/th>\nWhat it is<\/th>\nWhat it concerns<\/th>\n<\/tr>\n<\/thead>\n
Chemical substance
L-DOPA (Levodopa), CAS 59-92-7<\/th>\n		A chemical concept \u2014 a molecule of defined structure. In itself it is neither a medicine nor a reagent; its status is conferred only by the form in which it has been manufactured and authorised.<\/td>\nchemistry, substance registries<\/td>\n<\/tr>\n
Medicinal product
historical trade names: Larodopa, Dopar, Bendopa, Brocadopa, Dopaidan, Dopalina, Dopasol, Eldopal, Insulamina, Pardopa, Cidandopa, Dopaflex, Maipedopa<\/th>\n		A pharmaceutical preparation: a defined pharmaceutical form, manufacture under GMP, registration dossier, safety surveillance. The substance is the active ingredient of medicines used for decades in Parkinson’s disease, usually in combination with a peripheral decarboxylase inhibitor (carbidopa or benserazide). In Poland it is dispensed only on prescription.<\/strong><\/td>\nclinical studies involving humans concerned this entity<\/strong><\/td>\n<\/tr>\n
Chemical reagent
material offered here<\/th>\n		Material for laboratory and analytical work. It does not and cannot hold any authorisation for use in humans or animals<\/strong> \u2014 it has no pharmaceutical form and no medicinal product documentation.<\/td>\nanalytics, chemistry, reference standards<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

The consequence is unambiguous.<\/strong> The research results cited further on this page were obtained either with the registered medicinal product<\/strong> (clinical studies involving humans, the history of Parkinson’s disease treatment), or with the substance under laboratory conditions \u2014 in studies of plants, enzymes or analytical methods, without administering it to humans or animals<\/strong>. None of these studies was conducted with the analytical reagent offered on this page<\/strong>, and none of these results transfers to the material offered. The reagent is not a form in which the substance was ever administered to humans, and it cannot be used in such a way.<\/p>\n

Reagent identification sheet<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Registry data and identifiers \u2014 L-DOPA<\/caption>\n
Systematic name (IUPAC)<\/th>\n(2S)-2-amino-3-(3,4-dihydroxyphenyl)propanoic acid<\/td>\n<\/tr>\n
Common name<\/th>\nL-DOPA, Levodopa (Lewodopa)<\/td>\n<\/tr>\n
CAS number<\/th>\n59-92-7<\/td>\n<\/tr>\n
Molecular formula<\/th>\nC9<\/sub>H11<\/sub>NO4<\/sub><\/td>\n<\/tr>\n
Molar mass<\/th>\n197.19 g\u00b7mol\u22121<\/sup><\/td>\n<\/tr>\n
Monoisotopic mass<\/th>\n197.0688 Da<\/td>\n<\/tr>\n
InChIKey<\/th>\nWTDRDQBEARUVNC-LURJTMIESA-N<\/td>\n<\/tr>\n
SMILES<\/th>\nC1=CC(=C(C=C1CC(C(=O)O)N)O)O<\/td>\n<\/tr>\n
PubChem CID<\/th>\n6047<\/a><\/td>\n<\/tr>\n
ChEMBL<\/th>\nCHEMBL3663399<\/td>\n<\/tr>\n
Melting point<\/th>\n285 \u00b0C (PubChem data, CID 6047)<\/td>\n<\/tr>\n
Form<\/th>\ncrystalline powder, white to off-white<\/td>\n<\/tr>\n
Purity<\/th>\n\u2265 99%<\/td>\n<\/tr>\n
Intended use<\/th>\nresearch reagent \u2014 not for human or animal consumption<\/strong><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Lineage of the molecule: from legumes to a breakthrough in neurology<\/h2>\n

L-DOPA is not a molecule designed in the laboratory \u2014 it is a natural, non-proteinogenic amino acid<\/strong>, isolated from plants before it was synthesised. It occurs in young shoots of the broad bean (Vicia faba<\/em>) and in the seeds of several leguminous plants of the genus Mucuna<\/em>, including Mucuna pruriens<\/strong> (velvet bean) \u2014 it is these seeds that today remain the main plant source of the molecule used in research on its biosynthesis and on methods for its determination [6<\/a>][7<\/a>].<\/p>\n

From isolation to oral therapy<\/h3>\n

The pharmacological history of the molecule is well documented in the review literature [1<\/a>][2<\/a>][3<\/a>]. The link between the plant molecule and a neurodegenerative disease proved crucial: in the mid-20th century the hypothesis of a role for dopamine in the central nervous system was formulated, and its deficiency was subsequently demonstrated in the striatum of the brains of people who had died with Parkinson’s disease. Because dopamine itself does not cross the blood\u2013brain barrier, attention turned to its direct metabolic precursor, which is able to cross this barrier. The first attempts to administer L-DOPA to patients were intravenous, and the breakthrough came only with the development of an oral regimen, which showed lasting improvement in the motor symptoms of Parkinson’s disease [2<\/a>][3<\/a>]. Since then levodopa has been the point of reference for the pharmacotherapy of Parkinson’s disease \u2014 always in the form of a registered medicinal product, never in the form of an analytical reagent.<\/p>\n

A dopamine precursor \u2014 why this particular molecule<\/h3>\n

L-DOPA is the direct metabolic precursor of dopamine: the conversion is carried out by the enzyme aromatic L-amino acid decarboxylase (AADC, also called DOPA decarboxylase), which cleaves off the carboxyl group of the molecule. This is the same class of enzymes that produces serotonin from 5-hydroxytryptophan \u2014 which is why 5-HTP<\/a>, offered separately, is sometimes cited as a molecule analogous in terms of the enzymatic pathway, despite the different arrangement of substituents on the aromatic ring. An earlier link in the same biosynthetic pathway is in turn L-tyrosine<\/a>, from which L-DOPA is formed by tyrosine hydroxylase through the addition of a second hydroxyl group to the ring.<\/p>\n

Timeline<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n
Timeline: from plant isolation to modern analytics<\/caption>\n
1913<\/th>\nisolation of L-DOPA from young shoots of the broad bean (Vicia faba<\/em>) \u2014 one of the first works on this amino acid in plant chemistry<\/td>\n<\/tr>\n
1950s<\/th>\nformulation of the hypothesis of a role for dopamine in the central nervous system [1<\/a>]<\/td>\n<\/tr>\n
1960<\/th>\ndetection of dopamine deficiency in the striatum of the brains of patients with Parkinson’s disease [1<\/a>]<\/td>\n<\/tr>\n
1961<\/th>\nfirst intravenous administrations of L-DOPA to patients as part of experimental studies [2<\/a>]<\/td>\n<\/tr>\n
1967<\/th>\ndemonstration of the efficacy of oral administration \u2014 a turning point for the pharmacotherapy of Parkinson’s disease [3<\/a>]<\/td>\n<\/tr>\n
1970s\u20131980s<\/th>\nregistrations as a medicinal product<\/strong> in successive countries; introduction of combination preparations with a peripheral decarboxylase inhibitor<\/td>\n<\/tr>\n
2011\u20132019<\/th>\ndevelopment of quantitative methods for determining L-DOPA in Mucuna pruriens<\/em> seeds: HPTLC [6<\/a>], analysis of the biosynthetic pathway [7<\/a>], quantitative NMR [8<\/a>]<\/td>\n<\/tr>\n
2024<\/th>\ndescription of the dynamics of L-DOPA accumulation in the broad bean at the level of gene expression [9<\/a>]<\/td>\n<\/tr>\n
2019\u20132026<\/th>\ndevelopment of electrochemical biosensors and methods for chiral recognition of L-DOPA\/D-DOPA [14<\/a>][11<\/a>][12<\/a>]<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Directions of current research<\/h2>\n

The literature on L-DOPA is not concentrated around a single centre \u2014 activity is today spread across three independent directions: the biochemistry of leguminous plants<\/strong> (why Mucuna pruriens<\/em> and the broad bean accumulate L-DOPA in their seeds [7<\/a>][9<\/a>]), analytical chemistry<\/strong> (L-DOPA as a classic analyte for methods with electrochemical detection [10<\/a>][13<\/a>]) and chiral recognition<\/strong> \u2014 sensors that distinguish L-DOPA from D-DOPA without chromatographic separation [11<\/a>][12<\/a>], building on the enzymatic basis of this distinction [5<\/a>].<\/p>\n

Chemistry: a catechol amino acid with a stereogenic centre at the \u03b1-carbon<\/h2>\n

Why the L form, not the D form, matters biochemically<\/h3>\n

The molecule has one stereogenic centre \u2014 the \u03b1-carbon of the amino acid, to which four different substituents are attached: the amino group, the carboxyl group, a hydrogen atom and the catechol substituent. The designation (2S)<\/strong> in the IUPAC name corresponds to the designation L-<\/strong> in traditional amino acid nomenclature, in line with the rule that applies to most natural proteinogenic and non-proteinogenic amino acids. The D-DOPA enantiomer exists and is available as a separate standard, but it is not the form used by the enzymes of the catecholamine pathway.<\/p>\n

This distinction is not purely theoretical. The work of Wu and co-workers showed that D-DOPA is not simply metabolically inert \u2014 it is unidirectionally converted to L-DOPA<\/strong> by an enzymatic route, first by D-amino acid oxidase and then by dopa transaminase [5<\/a>]. For a laboratory working with both standards, this means that the mere presence of an L-DOPA signal in a biological sample does not establish which form was originally administered \u2014 a method that separates the enantiomers is needed [11<\/a>][12<\/a>].<\/p>\n

The catechol group: electroactivity and susceptibility to oxidation<\/h3>\n

The second structural hallmark is the catechol<\/strong> (ortho-dihydroxybenzene) ring. The two adjacent hydroxyl groups on the aromatic ring are readily oxidised to the ortho-quinone form \u2014 this susceptibility to oxidation makes L-DOPA an exceptionally good analyte for electrochemical detection<\/strong> (low oxidation potential, a strong and selective signal against the biological matrix background) and explains the number of recent papers on electrodes and biosensors dedicated to this molecule [13<\/a>][14<\/a>]. The same reactivity has a practical consequence for storage of the material \u2014 see the section below.<\/p>\n

Physicochemical characteristics<\/h3>\n\n\n\n\n\n\n\n\n\n
Computed descriptors and their analytical significance<\/caption>\n
Parameter<\/th>\nValue<\/th>\nWhat follows from it<\/th>\n<\/tr>\n<\/thead>\n
Partition coefficient (XLogP)<\/th>\n\u2248 \u22122.7<\/td>\nstrong hydrophilicity \u2014 the molecule elutes early in RP-HPLC, the opposite behaviour to most of the catalogue<\/td>\n<\/tr>\n
Topological polar surface area<\/th>\n104 \u00c52<\/sup><\/td>\nvery high for a molecule of this size \u2014 a result of the amino, carboxyl and two hydroxyl groups<\/td>\n<\/tr>\n
Hydrogen bond donors<\/th>\n4<\/td>\nthe amino group, the carboxyl group and the two catechol hydroxyls<\/td>\n<\/tr>\n
Hydrogen bond acceptors<\/th>\n5<\/td>\ncarboxyl oxygen (\u00d72) and two catechol oxygens, plus the nitrogen<\/td>\n<\/tr>\n
Solubility<\/th>\ngood in water and dilute acids; poor in non-polar organic solvents<\/td>\nprepare stock solutions in acidified water or in dilute acid, not in the organic solvents typical for the rest of the catalogue<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Nomenclature and synonyms: why \u201cDOPA\u201d is an abbreviation<\/h2>\n

The name DOPA derives from the first letters of the German term for dihydroxyphenylalanine \u2014 the abbreviation caught on faster than the full systematic name and today functions as the common name in most languages, including Polish. The prefix L- distinguishes the natural enantiomer from its mirror image, D-DOPA.<\/p>\n

Several equivalent designations of the same molecule with CAS number 59-92-7 are in chemical and bibliographic use:<\/p>\n