Levodopa, also known as L-DOPA or 3,4-dihydroxy-L-phenylalanine, is a naturally occurring amino acid and a critical precursor in the biosynthesis of the neurotransmitters dopamine, norepinephrine, and epinephrine. With the molecular formula C9H11NO4, levodopa is a large, neutral amino acid that plays a significant role in the treatment of Parkinson’s disease due to its ability to cross the blood-brain barrier and be converted into dopamine.
Chemically, levodopa is synthesized from the precursor amino acid tyrosine through the action of the enzyme tyrosine hydroxylase. As a medication, levodopa is often formulated with a peripheral DOPA decarboxylase inhibitor to reduce its conversion to dopamine outside the brain, thereby increasing its effectiveness and reducing side effects.
Levodopa is characterized by its effectiveness in alleviating the motor symptoms of Parkinson’s disease, such as tremors, rigidity, and bradykinesia. It is typically administered orally and absorbed from the gastrointestinal tract, where it is then transported to the brain.
In summary, levodopa is a vital pharmaceutical compound used in neurology for its role in treating Parkinson’s disease by replenishing the brain’s dopamine levels. Its targeted delivery and conversion to dopamine make it an essential treatment option for managing the motor symptoms associated with this condition.
描述
| Levodopa Chemical Properties |
| Melting point | 276-278 ??C (lit.) |
| Boiling point | 334.28??C (rough estimate) |
| alpha | -11.7 o (c=5.3, 1N HCl) |
| density | 1.3075 (rough estimate) |
| refractive index | -12 ?? (C=5, 1mol/L HCl) |
| storage temp. | 2-8??C |
| solubility | Slightly soluble in water, practically insoluble in ethanol (96 per cent). It is freely soluble in 1 M hydrochloric acid and sparingly soluble in 0.1 M hydrochloric acid . |
| pka | 2.32(at 25??) |
| form | Crystalline Powder |
| color | White to creamy |
| Odor | at 100.00 %. odorless |
| Odor Type | odorless |
| Water Solubility | Slightly soluble in water, dilute hydrochloric acid and formic acid. Insoluble in ethanol. |
| Merck | 14,5464 |
| BRN | 2215169 |
| Stability: | Stable. Incompatible with strong oxidizing agents. Light and air sensitive. |
| InChIKey | WTDRDQBEARUVNC-LURJTMIESA-N |
| LogP | -1.154 (est) |
| CAS DataBase Reference | 59-92-7(CAS DataBase Reference) |
| NIST Chemistry Reference | Levodopa(59-92-7) |
| EPA Substance Registry System | Levodopa (59-92-7) |
| Safety Information |
| Hazard Codes | Xn |
| Risk Statements | 22-36/37/38-20/21/22 |
| Safety Statements | 26-36-24/25 |
| WGK Germany | 3 |
| RTECS | AY5600000 |
| F | 10-23 |
| TSCA | Yes |
| HS Code | 29225090 |
| Hazardous Substances Data | 59-92-7(Hazardous Substances Data) |
| Toxicity | LD50 in mice (mg/kg): 3650 ??327 orally, 1140 ??66 i.p., 450 ??42 i.v., >400 s.c.; in male, female rats (mg/kg): >3000, >3000 orally; 624, 663 i.p.; >1500, >1500 s.c. (Clark) |
