L-ARGININE

L-Arginine is an amino acid commonly found as a component of total parenteral nutrition.
L-Arginine is an amino acid that plays a key role in many physiological processes such as tissue repair and reproduction. 
L-Arginine is a key precursor for synthesizing nitric oxide in mammals. 

CAS Number: 74-79-3
Molecular Formula: C6H14N4O2
Molecular Weight: 174.2
EINECS Number: 200-811-1

Synonyms:L-arginine, arginine, L-(+)-Arginine, L(+)-Arginine, (L)-Arginine, L-Arg, Arginine, L-, Arginina, Argininum, Arginine [USAN:INN], Arginine [USP:INN], Arginine CRS, Arginine (USP/INN), Arginine (VAN), Arginine (for injection), Arginine Base, (S)-2-Amino-5-guanidinopentanoic acid, (2S)-2-amino-5-guanidinopentanoic acid, 2-amino-5-guanidinopentanoic acid, 2-AMINO-5-GUANIDINO-PENTANOIC ACID, Pentanoic acid, 2-amino-5-((aminoiminomethyl)amino)-, (S)-, Pentanoic acid, 2-amino-5-[(aminoiminomethyl)amino]-, (S)-, (S)-(+)-arginine, L-alpha-Amino-delta-guanidinovaleric acid, L-2-Amino-5-guanidinopentanoic acid, L-a-Amino-d-guanidinovaleric acid, 1-Amino-4-guanidovaleric acid, 2-amino-5-guanidinovalerate, L-alpha-Amino-delta-guanidinovalerate, (S)-2-Amino-5-((aminoiminomethyl)amino)pentanoic acid, (S)-2-Amino-5-[(aminoiminomethyl)amino]pentanoic acid, (2S)-2-amino-5-(diaminomethylideneamino)pentanoic acid, (2S)-2-amino-5-((diaminomethylidene)amino)pentanoic acid, (2S)-2-amino-5-(carbamimidamido)pentanoic acid, N5-(aminoiminomethyl)-L-Ornithine, L-Ornithine, N5-(aminoiminomethyl)-, Norvaline, 5- (aminoiminomethyl)amino]-, (L)-, L-Norvaline, 5-[(aminoiminomethyl)amino]-, Argamine, Argivene, Detoxargin, Levargin, Minophagen A, Hypertensolol, Hypertenevide-12.5, Lytensopril, Lytensopril-90, H-Arg-OH, H-Arg, L-ARGININE [FCC], L-ARGININE [USP-RS], L-ARGININE [JAN], L-ARGININE [FHFI], L-ARGININE [WHO-DD], L-ARGININE [EP MONOGRAPH], L-ARGININE [USP MONOGRAPH],  CAS-74-79-3, EINECS 200-811-1, UNII-94ZLA3W45F, CHEBI:16467, CHEBI:29016, DTXSID6041056, DTXCID4021056, NSC-206269, CCRIS 3609, HSDB 1429, BRN 1725413, MFCD00002635, CHEMBL1485, DB00125, C6H14N4O2, InChI=1/C6H14N4O2/c7-4(5(11)12)2-1-3-10-6(8)9/h4H,1-3,7H2,(H,11,12)(H4,8,9,10)/t4-/m0/s; ABL2 (38-end), active, His tagged human;FLJ41441;ANTI-ABL2 antibody produced in mouse;FLJ22224;FLJ31718;Abelson murine leukemia viral oncogene homolog 2;Abelson tyrosine-protein kinase 2;ABL2.

L-Arginine is a naturally occurring α-amino acid containing a strongly basic guanidino functional group that gives the molecule high alkalinity and strong hydrogen-bonding capability. 
L-Arginine exists predominantly as a zwitterion in aqueous solutions at physiological pH, which enhances its water solubility and ionic reactivity in biological and chemical systems. 
Chemically, it is classified as a polar, positively charged amino acid with high nitrogen content, making it highly active in proton transfer, salt formation, and coordination interactions.

Due to these factors, the dietary supplementation with L-arginine may show a range of health benefits.
L-arginine is an amino acid that helps the body build protein.
L-arginine is an amino acid that you can find naturally in foods like fish, meat and nuts.

In chemical and biochemical processes, L-Arginine acts as a nitrogen donor and buffering agent, and it participates in acid–base equilibria due to its multiple amine functionalities. 
The guanidinium group exhibits resonance stabilization, allowing strong electrostatic interactions with anions and metal ions in solution chemistry. 
Its stereochemistry is fixed in the L-configuration, which is the biologically active enantiomer used in pharmaceutical, food, and laboratory applications.

L-Arginine is commonly supplied as a white to off-white crystalline powder that is odorless, hygroscopic, and readily soluble in water while being practically insoluble in most nonpolar organic solvents. 
L-Arginine shows thermal stability under normal storage conditions but may decompose upon prolonged heating or strong oxidative environments. 
Because of its high polarity and ionic nature, it is frequently formulated as salts or buffered solutions in chemical manufacturing and analytical laboratories.

L-Arginine can stimulate the human body to release certain chemicals such as insulin and human growth hormone. 
It can also clear ammonia in the body and promote the healing of wounds. 
The human body also needs it to produce sarcosine. Decomposing L-Arginine produces nitric oxide, which can expand blood vessels and increase blood flow. 

L-Arginine is an intermediate metabolite in the orthinine cycle and promotes the conversion of ammonia to urea, thus lowering the blood concentration of ammonia. 
L-Arginine is also an important part of sperm protein and can promote spermatogenesis and provide energy for sperm movement. 
Additionally, intravenous arginine can stimulate the pituitary to release growth hormone and can be used to test pituitary functions.

L-arginine is an amino acid, a building block of protein, that is crucial for various bodily functions. 
It is categorized as a semi-essential amino acid because although the body can produce it on its own, there are times when dietary intake or supplementation becomes necessary.
One of the key roles of L-arginine is its involvement in the production of nitric oxide (NO), a molecule known for its vasodilatory effects. 

This means that it helps to relax and widen blood vessels, which in turn improves blood flow throughout the body. 
This effect is particularly important for cardiovascular health, as proper blood circulation supports heart function and overall cardiovascular performance.
L-arginine is an L-alpha-amino acid that is the L-isomer of arginine. 

L-Arginine has a role as a nutraceutical, a biomarker, a micronutrient, an Escherichia coli metabolite and a mouse metabolite.
L-Arginine is a glutamine family amino acid, a proteinogenic amino acid, an arginine and a L-alpha-amino acid.
Abdominal pain, diarrhea, gout and bloating. 

There may also be increased severity in herpes breakouts and increased effects of antihypertensive drugs, resulting in a lower blood pressure than expected, which may cause hypertensive patients to experience dizziness and fainting.
L-Arginine is a diaminomonocarboxylic acid. 
The nonessential amino acid, arginine, is a urea cycle amino acid and a precursor for the neurotransmitter nitric oxide, which plays a role in the regulation of the brain’s system of dilation and constriction of small blood vessels. 

L-Arginine is strongly alkaline and its water solutions absorb carbon dioxide from the air (FCC, 1996). Functionality in foods includes, but is not limited to, nutrient and dietary supplement
L-arginine is considered to be generally safe. 
L-Arginine might be effective at lowering blood pressure, reducing the symptoms of angina and PAD, and treating erectile dysfunction due to a physical cause.

L-arginine is an amino acid, often referred to as simply “arginine,” that plays crucial roles in various physiological functions within the human body. 
L-Arginine is considered semi-essential, meaning that while the body can typically produce it on its own, there are times when supplementation may be necessary, such as during periods of growth, injury, or illness.

L-Arginine is the amino acid with the formula (H2N)(HN)CN(H)(CH2)3CH(NH2)CO2H. 
The molecule features a guanidino group appended to a standard amino acid framework. 
At physiological pH, the carboxylic acid is deprotonated (−CO2−) and both the amino and guanidino groups are protonated, resulting in a cation. 

Only the l-arginine (symbol Arg or R) enantiomer is found naturally.
Arg residues are common components of proteins. 
L-Arginine is encoded by the codons CGU, CGC, CGA, CGG, AGA, and AGG.

The guanidine group in arginine is the precursor for the biosynthesis of nitric oxide.
Like all amino acids, it is a white, water-soluble solid.

Melting point: 222 °C (decomposes)
Optical rotation (alpha): +27.1° (c = 8, 6 N HCl)
Boiling point: 305.18 °C (rough estimate)
Density: 1.2297 (rough estimate)
Bulk density: 640 kg/m³
FEMA number: 3819 (L-Arginine)
Refractive index (optical rotation reference): +27° (c = 8, 6 mol/L HCl)
Storage temperature: 2–8 °C
Solubility: 100 mg/mL in water
Water solubility: 148.7 g/L at 20 °C
Form: Powder
Color: White
Odor: Faint
Odor type: Bland
pKa: 1.82, 8.99, 12.5 at 25 °C
pH: 10.5–12.0 (0.5 M in H₂O at 25 °C)
pH range: 10.5–12
Biological source: Synthetic
Optical activity: [α]²⁰/D +27°, c = 8 in 6 M HCl
Sensitive: Air sensitive
λmax (UV): 260 nm (Amax ≤ 0.2); 280 nm (Amax ≤ 0.1)
Merck index: 14,780
JECFA number: 1438
Specific activity: 1035–1401 nmol/min·mg
BRN: 1725413
Stability: Stable; incompatible with strong oxidizing agents
Cosmetic ingredient function: Fragrance
Cosmetic ingredient function: Antistatic
Cosmetic ingredient function: Hair conditioning
Cosmetic ingredient function: Skin conditioning
InChIKey: ODKSFYDXXFIFQN-BYPYZUCNSA-N
LogP: −4.20

L-Arginine odorless, slightly bitter. 
Easily soluble in water (solubility in 0℃ water is 83g/L, solubility in 50℃ water is 400g/L), very slightly soluble in ethanol, insoluble in ether; pI6.0; loses its 2-molecule water crystal when heated to 105℃, darkens in color at 230℃, disintegrates at 244℃; its aqueous solution has maximum absorption at 205nm (1gε3.28).

L-Arginine is an encoding amino acid in protein synthesis and is one of the 8 essential amino acids in the human body. 
The body needs it for many different functions. 
Taking L-Arginine supplements can treat certain diseases such as congestive heart failure and cystitis. 

L-Arginine can also act as seasoning for nutrient supplements and food additives. 
L-Arginine can undergo a heat reaction with sugar (amino-carbonyl reaction) to obtain a unique fragrance, GB 2760-2001, an approved food spice. 
As an amino acid drug, L-Arginine can be used as pharmaceutical raw material and is an important ingredient in amino acid infusions and integrated amino acid preparations. 

L-Arginine is also a crucial amino acid in maintaining infant growth and maturation.
Enzymatically, arginine is formed in two reactions from citrulline. 
The first reaction (citrulline + succinate) is catalyzed by the enzyme arginosuccinate synthetase. 

L-Arginine is ATP dependent and with the formation of a new C–N bond in the gaunidino group of arginosuccinate, water is removed and ATP is hydrolyzed. 
The second reaction is catalyzed by arginine synthetase and involves the scission of arginosuccinate with the formation of arginine and fumaric acid.
L-arginine is an amino acid naturally found in red meat, poultry, fish, and dairy. 

L-Arginine is necessary for making proteins and is commonly used for circulation.
L-Arginine was first isolated in 1886 from yellow lupin seedlings by the German chemist Ernst Schulze and his assistant Ernst Steiger.
He named it from the Greek árgyros (ἄργυρος) meaning "silver" due to the silver-white appearance of arginine nitrate crystals.

In 1897, Schulze and Ernst Winterstein (1865–1949) determined the structure of arginine.
Schulze and Winterstein synthesized arginine from ornithine and cyanamide in 1899, but some doubts about arginine's structure lingered until Sørensen's synthesis of 1910.
L-Arginine is a chiral, proteinogenic α-amino acid containing one primary amine, one carboxylic acid group, and a highly basic guanidino side chain that dominates its chemical behavior. 

The guanidinium group has a very high pKa value, meaning it remains protonated and positively charged across a wide pH range, which enhances ionic interactions and salt-forming capacity. 
In aqueous media, the molecule exists mainly as a dipolar zwitterion, providing high aqueous solubility and strong electrostatic stability.
From a molecular chemistry perspective, L-arginine participates in extensive hydrogen bonding networks due to multiple donor and acceptor sites on the amine and guanidino groups. 

The resonance-stabilized guanidinium moiety distributes positive charge across three nitrogen atoms, increasing molecular rigidity and interaction strength with anions, phosphates, and carboxylates. 
This property makes L-arginine useful in crystallization control, buffering systems, and stabilization of charged biomolecules.
L-Arginine exhibits strong hygroscopic behavior and readily absorbs moisture from air, which can influence flowability and storage stability in powdered form. 

L-Arginine decomposes rather than melts when exposed to high temperatures, which is characteristic of many amino acids containing multiple ionic centers. 
Chemically, it is compatible with dilute acids and bases but may undergo degradation under strong oxidizing conditions or prolonged exposure to high humidity and heat.
In solution chemistry, L-arginine can act as a mild organic base and proton shuttle, supporting acid–base catalysis and pH stabilization in buffered systems. 

L-Arginine readily forms crystalline salts with mineral and organic acids, improving solubility control and formulation stability. 
Due to its strong polarity, partitioning into organic solvents is extremely limited, reinforcing its preference for aqueous environments.
From an analytical chemistry standpoint, L-arginine is identified using techniques such as infrared spectroscopy for guanidino stretching vibrations, nuclear magnetic resonance for proton and carbon framework confirmation, and high-performance liquid chromatography for purity and enantiomeric control. 

Its optical activity confirms the L-configuration, which is critical for pharmaceutical and biochemical consistency. 
These physicochemical characteristics make L-arginine a widely standardized reference compound in chemical and industrial laboratories.
L-Arginine is traditionally obtained by hydrolysis of various sources of protein, such as gelatin.

L-Arginine is obtained commercially by fermentation. 
In this way, 25-35 g/liter can be produced, using glucose as a carbon source.
L-Arginine is classified as a semiessential or conditionally essential amino acid, depending on the developmental stage and health status of the individual.

Preterm infants are unable to synthesize arginine internally, making the amino acid nutritionally essential for them.
Most healthy people do not need to supplement with arginine because it is a component of all protein-containing foods and can be synthesized in the body from glutamine via citrulline.
Additional, dietary arginine is necessary for otherwise healthy individuals temporarily under physiological stress, for example during recovery from burns, injury or sepsis, or if either of the major sites of arginine biosynthesis, the small intestine and kidneys, have reduced function, because the small bowel does the first step of the synthesizing process and the kidneys do the second.

L-Arginine is an essential amino acid for birds, as they do not have a urea cycle.
For some carnivores, for example cats, dogs[20] and ferrets, arginine is essential, because after a meal, their highly efficient protein catabolism produces large quantities of ammonia which need to be processed through the urea cycle, and if not enough arginine is present, the resulting ammonia toxicity can be lethal.

This is not a problem in practice, because meat contains sufficient arginine to avoid this situation.
Animal sources of arginine include meat, dairy products, and eggs, and plant sources include seeds of all types, for example grains, beans, and nuts.

Uses:
L-Arginine is used for heart and blood vessel conditions which includes congestive heart failure (CHF), chest pain, high blood pressure and coronary artery disease. 
It plays a vital role in the treatment of cardiovascular disease due to it being antiatherogenic, anti-ischemic, antiplatelet and antithrombotic. 
L-Arginine acts as a growth stimulant and is involved in the treatment of erectile dysfunction in men. 

L-Arginine is an important ingredient of tooth paste which provides effective relief for sensitive teeth.
L-Arginine is widely used in pharmaceutical formulations as an active ingredient and excipient for cardiovascular therapy, metabolic support, and nitric oxide–related treatments. 
It is incorporated into injectable solutions, oral supplements, and clinical nutrition products to support vascular function, immune response, and wound healing. 

In hospital settings, it is used in parenteral nutrition to supply essential nitrogen and amino acid balance.
In the food and nutraceutical industry, L-arginine is added to dietary supplements, sports nutrition products, and functional foods to enhance protein metabolism, muscle recovery, and circulation support. 
L-Arginine is used as a flavor precursor and fermentation nutrient in food processing due to its nitrogen-rich structure. 

The compound also acts as a pH stabilizer and amino acid fortifier in specialized formulations.
In biotechnology and laboratory applications, L-arginine is used as a cell culture supplement, protein refolding additive, and enzyme reaction stabilizer. 
L-Arginine helps prevent protein aggregation during recombinant protein purification and enhances solubility of charged biomolecules in buffer systems. 

Analytical laboratories use it as a calibration standard, reference material, and reagent in amino acid profiling.
In chemical and industrial processes, L-arginine is applied as a buffering agent, complexation reagent, and precursor for synthesis of arginine salts, peptides, and pharmaceutical intermediates. 
It is used in surface chemistry and materials research to modify charge behavior, stabilize dispersions, and control ionic interactions in aqueous systems. 

Its strong hydrogen bonding capacity enables controlled crystallization and formulation engineering.
In medical research and diagnostics, L-arginine serves as a biochemical probe for nitric oxide synthase activity, urea cycle evaluation, and metabolic pathway studies. 
L-Arginine is employed in clinical testing kits and experimental pharmacology to investigate endothelial function and amino acid transport mechanisms. 

These diverse applications make L-arginine a versatile compound across pharmaceutical, food, biotechnology, and chemical industries.
L-Arginine is extensively used in pharmaceutical manufacturing as a raw material for production of amino acid injections, oral tablets, effervescent powders, and sustained-release formulations. 
It improves bioavailability of active compounds through salt formation and ionic stabilization in complex drug systems. 

L-Arginine is also used as a buffering and tonicity-adjusting agent in sterile injectable preparations.
In clinical nutrition and medical nutrition therapy, L-arginine is incorporated into enteral and parenteral formulas to support tissue repair, immune modulation, and nitrogen balance in postoperative and critically ill patients. 
L-Arginine plays a role in enhancing collagen synthesis and accelerating wound healing in trauma and burn care. 

Specialized medical foods use L-arginine for metabolic support and vascular health optimization.
In sports science and performance nutrition, L-arginine is used in pre-workout supplements, recovery blends, and amino acid complexes to promote blood flow, nutrient delivery, and muscular endurance. 
L-Arginine supports creatine synthesis and ammonia detoxification during high-intensity exercise. 

Beverage concentrates, capsules, and powdered formulations frequently contain L-arginine as a functional ingredient.
In biotechnology, L-arginine is widely applied in recombinant protein production to suppress protein aggregation during refolding and purification processes. 
L-Arginine stabilizes enzymes and antibodies in solution by reducing intermolecular electrostatic attraction and hydrophobic collapse. 

It is also used as a nitrogen source in microbial fermentation and mammalian cell culture systems.
In analytical chemistry and quality control laboratories, L-arginine serves as a certified reference material for calibration of chromatographic systems, validation of amino acid analyzers, and development of pharmaceutical standards. 
L-Arginine is used in method development for HPLC, LC–MS, and capillary electrophoresis. 

Its well-defined chemical purity supports regulatory compliance and traceability.
In materials science and surface chemistry, L-arginine is applied as a surface modifier, dispersion stabilizer, and biofunctionalization agent due to its positive charge and hydrogen bonding capability. 
L-Arginine can promote adhesion, surface wettability control, and biomolecule immobilization on oxide, polymer, and metal surfaces. 

These properties make it useful in biosensor development, biomaterials engineering, and nanoparticle stabilization.
In agriculture and animal nutrition, L-arginine is added to feed formulations to support growth performance, immune strength, and reproductive efficiency in livestock and aquaculture. 

L-Arginine improves nitrogen utilization and protein metabolism in animal diets. 
Feed-grade arginine is manufactured at large scale for commercial nutrition markets.

Safety Profile:
L-Arginine is generally considered to have low acute toxicity and is not classified as a hazardous chemical under normal laboratory handling conditions. 
Dust or fine particles may cause mild irritation to the eyes, skin, and respiratory tract if inhaled or contacted directly. 
Prolonged or repeated exposure without proper hygiene may lead to dryness or slight discomfort of the skin.

Ingestion of large quantities may cause gastrointestinal effects such as nausea, abdominal cramps, bloating, and diarrhea. 
Excessive intake may influence blood pressure due to its vasodilatory effect and may interact with antihypertensive or nitrate-based medications. 
Individuals with kidney disease or metabolic disorders should avoid uncontrolled exposure or supplementation.

Contact with eyes may result in temporary redness, watering, or mild irritation. 
Skin contact is generally not harmful but prolonged exposure to moist material may cause localized irritation. 
Inhalation of airborne powder may cause coughing or throat irritation, especially in poorly ventilated environments.

L-Arginine is chemically stable under normal storage conditions but may degrade when exposed to strong oxidizing agents or excessive heat. 
Hygroscopic behavior can lead to moisture absorption, which may affect material flowability and purity over time. 
Decomposition products formed at high temperature may release nitrogen-containing fumes.

Environmental hazards are minimal, and the substance is considered biodegradable with low bioaccumulation potential. 
Large releases into water systems should still be avoided to prevent localized pH or nutrient imbalance. 
Waste material should be disposed of according to local laboratory or industrial chemical disposal regulations.