Quick Search
CAS no: 56-84-8
EC / List no: 200-291-6
Chemical formula: C4H7NO4
Synonyms: Aspartic acid, (+)-Aspartic acid, (+)-L-Aspartic acid, (S)-2-Aminobutanedioic acid, (S)-Aminobutanedioic acid, (S)-(+)-Aminosuccinic acid, L-Aspartic acid, L-α-Aminosuccinic acid, L-αlpha-Aminosuccinic acid, Asp, 2-Aminobutandioic acid, 2-aminobutanedioic acid, L-ASP, Ácido 2-aminobutanodioico
L-Aspartic Acid is a polar, acidic, proteinogenic alpha-amino acid. Possessing a carboxymethyl side chain (-CH2COOH), it is classified as a C4-dicarboxylic amino acid. Carried as a negatively charged species at physiological pH, L-Aspartic Acid plays a structural role in maintaining protein solubility, ionic balance, and active-site catalytic mechanism in enzymes.
Physiologically categorized as a non-essential amino acid in humans, it is synthesized endogenously via transamination of oxaloacetate in the citric acid cycle. It plays a pivotal metabolic role in nitrogen clearance (urea cycle), cellular energy conversion (Krebs cycle), nucleotide assembly, and central nervous system signaling. Commercially, L-Aspartic Acid is produced via enzymatic synthesis (using aspartase to convert fumaric acid and ammonia) or via targeted microbial fermentation.
Key Properties of L-Aspartic Acid
Molar Mass: 133.10 g/mol
Appearance: White crystalline powder or colorless crystals
Odor: Odorless (or faint characteristic odor)
Density: ~1.66 g/cm³
Boiling Point: Not applicable; decomposes before boiling
Melting Point: ~270–271 °C (decomposes upon heating)
Solubility: Slightly soluble in water (~4.5 g/L at 20 °C; increases with temperature); soluble in dilute acids and alkalis; insoluble in alcohol and ether
pH: Acidic in aqueous solution (typically pH ~2.5–3.0 in saturated solution)
Ionic Character: Acidic amino acid; anionic (negatively charged) at physiological pH due to its two carboxyl groups
Molecular Weight: 133.10 g/mol
Isoelectric Point (pI): ~2.77
Hygroscopicity / Water Absorption: Non-hygroscopic to low water-binding capacity
Stability: Stable under recommended dry, cool storage conditions; degrades under extreme heat, strong oxidizing agents, or strong bases
Core Mechanisms of Action & Biological Functions
Excitatory Neurotransmission: Acts as an acidic NMDA (N-methyl-D-aspartate) receptor agonist in the central nervous system. It depolarizes nerve cell membranes, promotes neuronal burst firing, and influences synaptic transmission, learning, and memory.
Urea Cycle & Ammonia Detoxification: Serves as a vital amine donor and substrate in the hepatic urea cycle, combining with citrulline to form argininosuccinate to clear toxic metabolic ammonia from the body.
Krebs Cycle & Cellular Energy Production: Interconverts with oxaloacetate via transamination, bridging amino acid catabolism directly into the Krebs (citric acid) cycle to generate ATP.
Precursor for Essential Biomolecules: Acts as a fundamental building block for the biosynthesis of other amino acids (asparagine, methionine, threonine, and lysine), pyrimidine nucleotides, and purines.
Enzymatic Catalysis & Biomineralization: Forms key catalytic residues inside enzyme active sites, maintaining protein surface charge and ionic balance. Regulates calcium carbonate biomineralization, nucleation, and crystal growth.
Industry Applications
Food Industry & Sweetener Manufacturing
Aspartame Synthesis: Serves as the primary monomeric building block (alongside L-phenylalanine) for the industrial synthesis of aspartame, a high-intensity, low-calorie sweetener.
Flavor Enhancement & Maillard Reactions: Utilized as a flavor enhancer, seasoning additive, and precursor in thermal amino-carbonyl (Maillard) reactions to develop roasted or savory flavor profiles in processed foods.
Food Preservation & pH Adjustment: Functions as a mild acidulant, preservative, and pH regulating/buffering agent in food formulations.
Pharmaceuticals & Clinical Therapeutics
Electrolyte & Mineral Transporter: Formulated into pharmaceutical aspartate salts (e.g., potassium aspartate, magnesium aspartate, iron aspartate) to enhance mineral bioavailability and manage electrolyte imbalances.
Parenteral & Enteral Nutrition: Essential component in intravenous amino acid infusions and enteral formulations used in liver disease, cirrhosis, cardiac disorders, and hyperammonemia.
Hepatic & Fatigue Recovery Therapeutics: Functions as a liver function promoter, ammonia antidote, and fatigue-recovery agent for physical overexertion, cerebral ischemia, and metabolic stress.
Sports Nutrition & Dietary Supplements
Ammonia Clearance & Fatigue Reduction: Used in sports formulations to mitigate exercise-induced hyperammonemia during strenuous exertion, supporting muscle endurance and physical recovery.
Hormonal & Metabolic Support: Formulated into wellness supplements targeting energy metabolism, endocrine regulation, and cognitive support.
Cosmetics & Personal Care
Moisturization & Barrier Support: Functions as a skin-conditioning agent and constituent of the skin's Natural Moisturizing Factor (NMF) in creams, serums, and anti-aging lotions.
Formulation Protection & Anti-Static Agent: Acts as an antioxidant inhibitor to protect cosmetic ingredients from oxidative degradation. Serves as an anti-static agent and deodorizing/neutralizing agent in hair masks, body washes, and personal hygiene products.
Industrial Polymers & Chemical Synthesis
Polyaspartic Acid (PASP) Production: Primary monomer for synthesizing polyaspartic acid—a biodegradable, non-toxic polymer used as an eco-friendly scale inhibitor, corrosion inhibitor, and dispersant in industrial water treatment, detergents, and agriculture.
Chemical Intermediate: Serves as a chiral synthons/precursor for preparing $\beta$-amino acid derivatives and specialized fine chemicals.
Fuel & Material Stabilizer: Functions as a charge stabilizer and anti-static additive in industrial formulations and diesel fuels.
Biotechnology & Laboratory Research
Cell Culture Media Component: Non-animal derived amino acid supplement used in serum-free cell culture media (e.g., for producing monoclonal antibodies and recombinant proteins).
Reference Standard & Reagent: Applied as a pharmaceutical secondary standard, analytical calibrant for quality control (LC-MS/MS), and biochemical reagent in neurobiology and ischemic research.
L-Aspartic Acid is a foundational dicarboxylic amino acid that connects core biological metabolism with high-value industrial applications. From driving cellular energy production and ammonia detoxification to serving as a key precursor for aspartame sweetener and biodegradable polyaspartic acid (PASP) polymers, its chemical utility is vast. Whether utilized as a pharmaceutical electrolyte carrier, a cosmetic skin conditioner, or a cell culture nutrient, L-Aspartic Acid remains a crucial, environmentally friendly biochemical building block across global manufacturing and health sectors.
