1.0 2020-03-18 23:26:00 UTC 2022-12-13 23:36:23 UTC CDB000133 L-Leucine Leucine, abbreviated as Leu or L, l-leucine, is an essential amino acid (meaning the body cannot synthesize it and it must be obtained from the diet) that is used in the biosynthesis of proteins. It contains an Œ±-amino group (which is in the protonated ‚àíNH3+ form under biological conditions), an Œ±-carboxylic acid group (which is in the deprotonated ‚àíCOO‚àí form under biological conditions), and a side chain isobutyl group, making it a non-polar aliphatic amino acid. Human dietary sources are foods that contain protein, such as meats, dairy products, soy products, beans and legumes. L-Leucine is a branched-chain amino acid (BCAA). BCAAs are essential amino acids whose carbon structure is marked by a branch point. These three amino acids are critical to human life and are particularly involved in stress, energy, and muscle metabolism. BCAA supplementation as therapy, both oral and intravenous, in human health and disease holds great promise. Despite their structural similarities, the branched amino acids have different metabolic routes, with valine going solely to carbohydrates, leucine solely to fats, and isoleucine to both. The different metabolism accounts for different requirements for these essential amino acids in humans: 12 mg/kg, 14 mg/kg, and 16 mg/kg of valine, leucine, and isoleucine, respectively. Furthermore, these amino acids have different deficiency symptoms. Valine deficiency is marked by neurological defects in the brain, while isoleucine deficiency is marked by muscle tremors. Many types of inborn errors of BCAA metabolism exist and are marked by various abnormalities. The most common form is the maple syrup urine disease (PMID: 10234605), marked by a characteristic sweet smell of urine. Other abnormalities are associated with a wide range of symptoms, such as mental retardation, ataxia, hypoglycemia, spinal muscle atrophy, rash, vomiting, and excessive muscle movement. Most forms of BCAA metabolism errors are corrected by dietary restriction of BCAA and at least one form is correctable by supplementation with 10 mg of biotin daily. BCAA are useful because they are metabolized primarily by muscle and particularly leucine, are most essential for muscle health. BCAA and other amino acids are frequently fed intravenously (TPN) to malnourished surgical patients and, in some cases, those with severe trauma. BCAA, particularly leucine, stimulate protein synthesis, increase reutilization of amino acids in many organs and reduce protein breakdown. Furthermore, leucine can be an important source of calories, and is superior as fuel to the ubiquitous intravenous glucose (dextrose). Leucine also stimulates insulin release, which in turn stimulates protein synthesis and inhibits protein breakdown. These effects are particularly useful in athletic training. BCAA should also replace the use of steroids by weightlifters. Huntington's chorea and anorexic disorders both are characterized by low serum BCAA. These diseases, as well as forms of Parkinson's, may respond to BCAA therapy. L-Leucine can be found in most biofluids, including blood, cerebrospinal fluid (CSF), feces, and sweat, as well as throughout most human tissues. L-Leucine exists in all living species, ranging from bacteria to humans. L-leucine is also found in Cannabis plants (PMID: 6991645). (2S)-2-Amino-4-methylpentanoic acid (2S)-alpha-2-Amino-4-methylvaleric acid (2S)-alpha-Leucine (S)-(+)-Leucine (S)-Leucine 2-Amino-4-methylvaleric acid L L-Leucin L-Leuzin Leu LEUCINE (2S)-2-Amino-4-methylpentanoate (2S)-a-2-Amino-4-methylvalerate (2S)-a-2-Amino-4-methylvaleric acid (2S)-alpha-2-Amino-4-methylvalerate (2S)-Α-2-amino-4-methylvalerate (2S)-Α-2-amino-4-methylvaleric acid (2S)-a-Leucine (2S)-Α-leucine 2-Amino-4-methylvalerate (S)-2-Amino-4-methylpentanoate (S)-2-Amino-4-methylpentanoic acid (S)-2-Amino-4-methylvalerate (S)-2-Amino-4-methylvaleric acid 4-Methyl-L-norvaline L-(+)-Leucine L-a-Aminoisocaproate L-a-Aminoisocaproic acid L-alpha-Aminoisocaproate L-alpha-Aminoisocaproic acid Leucine, L-isomer L-Isomer leucine Leucine, L isomer C6H13NO2 131.17 131.0946 (2S)-2-amino-4-methylpentanoic acid L-leucine 71000-80-1 CC(C)C[C@H](N)C(O)=O InChI=1S/C6H13NO2/c1-4(2)3-5(7)6(8)9/h4-5H,3,7H2,1-2H3,(H,8,9)/t5-/m0/s1 ROHFNLRQFUQHCH-YFKPBYRVSA-N belongs to the class of organic compounds known as leucine and derivatives. Leucine and derivatives are compounds containing leucine or a derivative thereof resulting from reaction of leucine at the amino group or the carboxy group, or from the replacement of any hydrogen of glycine by a heteroatom. Leucine and derivatives Organic compounds Organic acids and derivatives Carboxylic acids and derivatives Amino acids, peptides, and analogues Aliphatic acyclic compounds Amino acids Carbonyl compounds Carboxylic acids Hydrocarbon derivatives L-alpha-amino acids Methyl-branched fatty acids Monoalkylamines Monocarboxylic acids and derivatives Organic oxides Organopnictogen compounds Aliphatic acyclic compound Alpha-amino acid Amine Amino acid Branched fatty acid Carbonyl group Carboxylic acid Fatty acid Fatty acyl Hydrocarbon derivative L-alpha-amino acid Leucine or derivatives Methyl-branched fatty acid Monocarboxylic acid or derivatives Organic nitrogen compound Organic oxide Organic oxygen compound Organonitrogen compound Organooxygen compound Organopnictogen compound Primary aliphatic amine Primary amine Common amino acids L-alpha-amino acid leucine proteinogenic amino acid pyruvate family amino acid water_solubility 21.5 mg/mL logp -1.52 HANSCH,C ET AL. (1995) melting_point 268 - 288 °C logp -1.82 ALOGPS logs -0.27 ALOGPS logp -1.6 ChemAxon pka_strongest_acidic 2.79 ChemAxon pka_strongest_basic 9.52 ChemAxon iupac (2S)-2-amino-4-methylpentanoic acid ChemAxon average_mass 131.17 ChemAxon mono_mass 131.0946 ChemAxon smiles CC(C)C[C@H](N)C(O)=O ChemAxon formula C6H13NO2 ChemAxon inchi InChI=1S/C6H13NO2/c1-4(2)3-5(7)6(8)9/h4-5H,3,7H2,1-2H3,(H,8,9)/t5-/m0/s1 ChemAxon inchikey ROHFNLRQFUQHCH-YFKPBYRVSA-N ChemAxon polar_surface_area 63.32 ChemAxon refractivity 34.17 ChemAxon polarizability 14.16 ChemAxon rotatable_bond_count 3 ChemAxon acceptor_count 3 ChemAxon donor_count 2 ChemAxon physiological_charge 0 ChemAxon formal_charge 0 ChemAxon number_of_rings 0 ChemAxon bioavailability 1 ChemAxon rule_of_five Yes ChemAxon ghose_filter Yes ChemAxon veber_rule Yes ChemAxon mddr_like_rule Yes ChemAxon DB00149 FDB000899 C00123 5880 15603 6106 LEU C00001377 33942 Leucine 24 Turner CE, Elsohly MA, Boeren EG: Constituents of Cannabis sativa L. XVII. A review of the natural constituents. J Nat Prod. 1980 Mar-Apr;43(2):169-234. doi: 10.1021/np50008a001. 6991645 Podebrad F, Heil M, Reichert S, Mosandl A, Sewell AC, Bohles H: 4,5-dimethyl-3-hydroxy-2[5H]-furanone (sotolone)--the odour of maple syrup urine disease. J Inherit Metab Dis. 1999 Apr;22(2):107-14. doi: 10.1023/a:1005433516026. 10234605