L-Glutamic Acid Hcl
L-Histidine Hcl
L-Lysine Acetate
L-Lysine Hcl
L-Ornithine Hcl
L-Pyroglutamic Acid
L-Homoarginine Hcl
DL-Arginine HCL
DL-Aspartic Acid
DL-Carnitine HCL
DL-Glutamic Acid
DL-Lysine Hcl
DL-Pyroglutamic Acid
D-Glucosamine Hcl
D-Glutamic Acid
D-Pyroglutamic Acid
D-Aspartic Acid
D-Arginine Hcl
D-Histidine Hcl
D-Ornitine Hcl


(CAS: 56-85-9)

Recommend Site

CAS: 56-85-9

Molecular formula: C5H10N2O3

Molecular weight: 146.15


L-glutamine is a protein amino acid found in proteins of all life forms. It is classified as a semi-essential or conditionally essential amino acid. This means that under normal circumstances the body can synthesize sufficient L-glutamine to meet physiological demands. However, there are conditions where the body cannot do so. Recently, L-glutamine has come to be regarded as one of the most important of the amino acids when the body is subjected to such metabolic stress situations as trauma (including surgical trauma), cancer, sepsis and burns. Under such conditions, L-glutamine becomes an essential amino acid, and it is therefore very important to ensure adequate intakes of the amino acid in order to meet the increased physiological demands created by these situations.

L-glutamine is the most abundant amino acid in the body, and plasma glutamine levels are the highest of any amino acid. L-glutamine is predominantly synthesized and stored in skeletal muscle. The amino acid L-glutamate is metabolized to L-glutamine in a reaction catalyzed by the enzyme glutamine synthase, a reaction which, in addition to L-glutamate, requires ammonia, ATP and magnesium.

L-glutamine is a very versatile amino acid and participates in many reactions in the body. It is important in the regulation of acid-base balance. L-glutamine allows the kidneys to excrete an acid load, protecting the body against acidosis. This is accomplished by the production of ammonia, which binds hydrogen ions, to produce ammonium cations that are excreted in the urine along with chloride anions. Bicarbonate ions are simultaneously released into the bloodstream. L-glutamine helps protect the body against ammonia toxicity by transporting ammonia, in the form of L-glutamine's amide group, from peripheral tissues to visceral organs, where it can be excreted as ammonium by the kidneys or converted to urea by the liver.

The amide group can also participate in other metabolic activities, as can the amino group of L-glutamine. L-glutamine serves as the most important nitrogen shuttle, supplying nitrogen for metabolic purposes (from glutamine-producing tissues, such as skeletal muscle) to glutamine-consuming tissues.

L-glutamine participates in the formation of purine and pyrimidine nucleotides, amino sugars (such as glucosamine), L-glutamate and other amino acids, nicotinamide adenine dinucleotide and glutathione. It also participates in protein synthesis, energy production and, if necessary, the production of D-glucose and glycogen. Importantly, L-glutamine can serve as the primary respiratory substrate for the production of energy in enterocytes and lymphocytes. L-glutamine is considered an immunonutrient, and supplemental L-glutamine is used in medical foods for such stress situations as trauma, cancer, infections and burns.

The typical dietary intake of L-glutamine is 5 to 10 grams daily. Most dietary L-glutamine comes from animal and plant proteins. Small amounts of free L-glutamine are found in vegetable juices and fermented foods, such as miso and yogurt. L-glutamine is the amide of L-glutamic acid. Its molecular formula is C 5 H 10 N 2 O 3 , and its molecular weight is 146.15 daltons. The structural formula is:

L-glutamine is also known as 2-aminoglutaramic acid, levoglutamide, (S)-2, 5-diamino-5-oxopentaenoic acid and glutamic acid 5-amide. Its one-letter abbreviation is Q, and it is also abbreviated as Gln. The terms L-glutamine and glutamine are used interchangeably. D-glutamine, the stereoisomer of L-glutamine, does not have, as far as is known, biological activity. L-glutamine is not very soluble in water, and aqueous solutions are unstable at temperatures of 22 to 24 degrees Celsius. For these reasons, the more soluble and more stable glutamine dipeptides are used as delivery forms of L-glutamine in total parenteral nutrition (TPN) solutions.



Abcouwer SF, Souba WW. Glutamine and arginine. In: Shils ME, Olson JA, Shike M, Ross AC, eds. Modern Nutrition in Health and Disease. 9 th ed. Baltimore, MD: Williams and Wilkins. 1999:559-569.

Anderson PM, Ramsay NK, Shu XO, et al. Effect of low-dose oral glutamine on painful stomatitis during bone marrow transplantation. Bone Marrow Transplant. 1998;22:339-344.

Anderson PM, Schroeder G, Skubitz KM. Oral glutamine reduces the duration and severity of stomatitis after cytotoxic cancer chemotherapy. Cancer. 1998;83:1433-1439.

Antonio J, Street C. Glutamine: a potentially useful supplement for athletes. Can J Appl Physiol. 1999;24:1-14.

Bulus N, Cersosimo E, Ghishan F, Abumrad NN. Physiologic importance of glutamine. Metabolism. 1989;38(Suppl1):1-5.

Byrne TA, Morrissey TB, Nattakom TV, et al. Growth hormone, glutamine, and a modified diet enhance nutrient absorption in patients with severe short bowel syndrome. J Parenter Enteral Nutr. 1995;19:296-302.

Cao Y, Feng Z, Hoos A, Klimberg VS. Glutamine enhances gut glutathione production. J Parenter Enteral Nutr. 1998;22:224-247.

Furukawa S, Saito H, Inoue T, et al. Supplemental glutamine augments phagocytosis and reactive oxygen intermediate production by neutrophils and monocytes from postoperative patients in vitro. Nutrition. 2000;16:323-329.

Furukawa S, Saito H, Ming-Tsan L, et al. Enteral administration of glutamine in purulent peritonitis. Nutrition. 1999;15:29-31.

Haub MD, Potteiger JA, Nau KL, et al. Acute L-glutamine ingestion does not improve maximal effort exercise. J Sports Med Phys Fitness. 1998;38:240-244.

Hond ED, Peeters M, Hiele M, et al. Effect of glutamine on the intestinal permeability changes induced by indomethacin in humans. Aliment Pharmacol Ther. 1999;13:679-685.

Houdijk, APJ, Rijnsburger ER, Jansen J, et al. Randomized trial of glutamine-enriched enteral nutrition on infectious morbidity in patients with multiple trauma. Lancet. 1998;352:772-776.

Huang EY, Leung SW, Wang CJ, et al. Oral glutamine to alleviate radiation-induced oral mucositis: a pilot randomized trial. Int J Rad Oncol Biol Phys. 2000;46:535-539.

Ito A, Higashiguchi T. Effects of glutamine administration on liver regeneration following hepatectomy. Nutrition. 1999;15:23-28.

Lacey JM, Wilmore DW. Is glutamine a conditionally essential amino acid? Nutr Rev. 1990;48:297-309.

Mebane AH. L-Glutamine and mania. Am J Psychiatry. 1984;141:1302-1303.

Neu J, Roig JC, Meetze WH, et al. Enteral glutamine supplementation for very low birth weight infants decreases mortality. J Pediatr. 1997;131:691-699.

Noyer CM, Simon D, Borczuk A, et al. A double-blind placebo-controlled pilot study of glutamine therapy for abnormal intestinal permeability in patients with AIDS. Am J Gastroenterol. 1998;93:972-975.

Rogers LL, Pelton RB, Williams RJ. Voluntary alcohol consumption of rats following administration of glutamine. J Biol Chem. 1955;214:503-506.

Rohde T, MacLean DA, Klarlund Pedersen B. Glutamine, lymphocyte proliferation and cytokine production. Scan J Immunol. 1996;44:648-650.

Rohde T, MacLean DA, Pedersen BK. Effect of glutamine supplementation on changes in the immune system induced by repeated exercise. Med Sci Sports Exerc. 1998;30:856-862.

Sacks GS. Glutamine supplementation in catabolic patients. Ann Pharmacother. 1999;33:348-354.

Wilmore DW, Schloerb PR, Ziegler TR. Glutamine in the support of patients following bone marrow transplantation. Curr Opin Clin Nutr Metab Care. 1999;2:323-327.

Windmueller HG, Spaeth AF. Identification of ketone bodies and glutamine as the major respiratory fuels in vivo for postabsorptive rat small intestine. J Biol Chem. 1978;253:69-76.

Ziegler TR, Benfell K, Smith RJ, et al. Safety and metabolic effects of L-glutamine administration in humans. J Parenter Enteral Nutr. 1990;14:137S-146S.