| 外観 | 白色, 結晶～結晶性粉末 |
| 定義 | 本品は、次の化学式で表されるアミノ酸である。 |
| 溶解性 | 水にやや溶けにくく、エタノールに極めて溶けにくい。 |
| 解説 | L-ロイシン,グルテン，カゼイン，ケラチンなどの加水分解物から等電点沈殿法，イオン交換法によりイソロイシンとの混合物を得，2-ブロモトルエン-5-スルホン酸塩かナフタレン-2-スルホン酸塩として分離する．発酵法でもつくられる．"光輝のある六方晶系．分解点293～295 ℃(封管中)，昇華点145～148 ℃．[α]25D－10.8°(水)．pK1 2.35，pK2 9.57(25 ℃)．pI5.98．1日当たりの必要量は成人14 mg/kg，幼児161 mg/kg．DL-ロイシンはイソカプロン酸の臭素化，アミノ化やイソバレルアルデヒドのストレッカー反応で合成される．融点293～295 ℃． 森北出版「化学辞典（第2版）
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| 用途 | 製剤研究用。アミノ酸研究用。 |
| 存在する | L-ロイシン,略号LeuまたはL．必須α-アミノ酸の一つ．タンパク質構成アミノ酸として，また遊離の状態で広く自然界に分布している． |
| 化粧品の成分用途 | ヘアコンディショニング剤、皮膚コンディショニング剤 |
| 効能 | ロイシン補充薬 |
| 説明 | Small, white, lustrous plates, or a white, crystalline powder, with
a slightly bitter taste. One g dissolves in about 40 mL of water
and in about 100 mL of acetic acid. It is sparingly soluble in
alcohol, but is soluble in dilute hydrochloric acid and in solutions
of alkali hydroxides and carbonates. ι-Leucine may be synthesized by bromination, followed by amination of isocaproic acid; via the
acetamidomalonic ester; by isolation from gluten, casein, keratin;
from hydantoin. |
| 化学的特性 | Leucine occurs as a white or almost off-white crystalline powder or
shiny flakes. |
| 化学的特性 | L-Leucine is odorless and has a slightly bitter taste. L-Leucine is a branched-chain, essential amino acid that stimulates
muscle protein synthesis. |
| 天然物の起源 | Reported found as a constituent in proteins; also present in the free state in the human body |
| 使用 | L-Leucine plays a vital role in hemoglobin formation, protein synthesis and metabolic functions. It assists the growth and repair of muscle and bone tissue. It is used in the treatment of amyotrophic lateral sclerosis - Lou Gehrig's disease. It prevents the breakdown of muscle proteins after trauma or severe stress and may be beneficial for individuals with phenylketonuria. It is also used as a food additive and flavor enhancer. Further, it is used to preserve muscle glycogen. |
| 使用 | L-Leucine is an essential amino acid. L-Leucine acts as a nutrient signal to stimulate protein synthesis. It has also activates the mammalian target of rapamycin kinase that regulates cell growth. |
| 使用 | L-Leucine is an essential amino acid. It is also considered to be a branched chain amino acid, along with L-Isoleucine and L-Valine. It is used as a cell culture media component in the commercial biomanufacture of therapeutic recombinant proteins and monoclonal antibodies. |
| 定義 | ChEBI: The L-enantiomer of leucine. |
| 調製方法 | Leucine is produced microbially by incubating an amino-acidproducing
microorganism including but not exclusive to Pseudomonas,
Escherichia, Bacillus, or Staphylococcus in the presence of
oxygen and a hydrocarbon. The nutrient medium should contain an
inhibitory amount of a growth inhibitor that is a chemically similar
derivative of leucine (e.g. methylallylglycine, a-hydrozinoisocaproic
acid, or b-cyclopentanealanine) to inhibit the growth of the
organism except for at least one mutant that is resistant to the
inhibitory effect. The resistant mutant is then isolated and grown in
the presence of oxygen and the hydrocarbon in the absence of the
inhibitor. The mutant cells are then harvested and a nutrient
medium is formed that includes a hydrocarbon as the sole source of
carbon. Finally, the harvested cells are incubated in the medium in
the presence of oxygen. |
| 製造方法 | By bromination followed by amination of isocaproic acid; via the acetamidomalonic ester; by isolation from gluten,
casein, keratin; from hydantoin. |
| 摂取量と疾患の関係 | ロイシンは幅広い食物に含まれます。そのため、通常の食生活で不足することは、ほとんどの場合ありません。ただし、不足した場合には肝機能の低下とそれに続くインスリン分泌量の減少などのリスクが示唆されています。
また、過剰に摂取した場合は、他のアミノ酸とのバランスが崩れ、免疫力の低下などの弊害を招く可能性があります。
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| 使用用途 | ロイシンは、その構造上の特徴から分岐鎖アミノ酸（BCAA; Branched Chain Amino Acid）に分類されます。BCAAには３種類のアミノ酸（ロイシン、イソロイシン、バリン）があり、これらのアミノ酸は筋繊維を構成するタンパク質の主成分であるため、筋肉を強化する効果が期待されます。また、ロイシンには、タンパク質合成に必要な酵素複合体を活性化する働きがあり、筋タンパク質合成を誘導することがわかっています。このような特徴から、ロイシンをはじめとするBCAAは、筋力トレーニング用のサプリメントとして広く用いられています。
また、ロイシンには肝機能の向上、ストレス緩和、耐糖能の改善、インスリン感受性の向上、育毛といった効果が報告されており、アミノ酸補給を目的とした医薬品や、食品添加物としても利用されています。
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| 応用例（製薬） | Leucine is used in pharmaceutical formulations as a flavoring
agent. It has been used experimentally as an antiadherent to
improve the deagglomeration of disodium cromoglycate micro-particles and other compounds in inhalation preparations; and as
a tablet lubricant. Leucine copolymers have been shown to
successfully produce stable drug nanocrystals in water. |
| Biochem/physiol Actions | Leucine is a non-glucogenic, essential amino acid. It is a branched-chain amino acid that is a structural component of proteins. Leucine positively influences insulin release to eliminate toxic sugars out of the blood. The degradation of leucine leads to the formation of ketone bodies. |
| 安全性 | Leucine is an essential amino acid and is consumed as part of a
normal diet. It is generally regarded as a nontoxic and nonirritant
material. It is moderately toxic by the subcutaneous route.
LD50 (rat, IP): 5.379 g/kg |
| 貯蔵 | Leucine is sensitive to light and moisture, and should be stored in an
airtight container in a cool, dark, dry place. |
| 純化方法 | Likely impurities are isoleucine, valine, and methionine. Crystallise L-leucine from water by adding 4 volumes of EtOH. It sublimes at 180-188o/0.3mm with 99.1% recovery, and unracemised [Gross & Gradsky J Am Chem Soc 77 1678 1955]. [Greenstein & Winitz The Chemistry of the Amino Acids J. Wiley, Vol 3 p 2075-2094 1961, Kameda et al. J Pharm Soc Jpn 78 763 1958, Beilstein 4 IV 2738.] |
| 不和合性 | Leucine is incompatible with strong oxidizing agents. |
| 規制状況(Regulatory Status) | Included in the FDA Inactive Ingredients Database (IV infusion; oral
tablets). Included in nonparenteral medicines licensed in the UK. |