Leucine

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  • Identifiers

    CAS number
    61-90-5

    Molecular formula
    C6H13NO2

    SMILES
    CC(C)C[C@@H](C(=O)O)N

  • Odor profile

    Fragrance
    Odorless 61.41%
    Cooling 37.0%
    Mint 32.52%
    Cheesy 25.01%
    Savory 24.48%
    Milky 18.61%
    Bitter 17.79%
    Sour 16.22%
    Fishy 15.38%
    Sweaty 15.38%

     

    Flavor
    Odorless 43.57%
    Mild 28.1%
    Bland 24.59%
    Sulfury 20.53%
    Acrid 19.92%
    Yeasty 19.85%
    Stinky 19.67%
    Bloody 19.63%
    Glue 19.36%
    Roquefort cheese 19.11%

     

    Odor impact est.
    Low

  • Properties

    XLogP3-AA
    -1.5

    pKa est.
    6.52 (neutral)

    Molecular weight
    131.17 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Very slow

    Melting point expt.

    • 293 °C
    • 268 - 288 °C

    Boiling point

    • Sublimes at 145-148 °C. Decomposes at 293-295 °C (rapid heating, sealed tube)

    Flash point

    • 110.8 ˚C est.

    Solubility expt.

    • 21500 mg/L (at 25 °C)
    • Leaflets from water. Sweet taste. Decomposes at 232 °C (also reported as 290 °C). Sublimes. pK1 = 2.36; pK2 = 9.60. Solubility in water (g/L): 7.97 (0 °C); 9.91 (25 °C); 14.06 (50 °C); 22.76 (75 °C); 42.06 (100 °C); in 90% alcohol: 1.3. Insoluble in ether. /Leucine DL-form/
    • Solubility in 99% alcohol: 0.72; in acetic acid: 10.9. Insoluble in ether.
    • Solubility in water (g/L): 22.7 (0 °C); 24.26 (25 °C); 28.87 (50 °C); 38.23 (75 °C); 56.38 (100 °C)
    • In water, 2.15X10+4 mg/L at 25 °C
    • 21.5 mg/mL
    • Soluble in water, acetic acid, dilute HCl, and alkaline hydroxides and carbonates
    • Slightly soluble (in ethanol)

  • Synonyms

    • L-leucine
    • leucine
    • 61-90-5
    • H-Leu-OH
    • (S)-Leucine
    • (S)-2-Amino-4-methylpentanoic acid
    • (2S)-2-amino-4-methylpentanoic acid
    • Leucin
    • (S)-(+)-Leucine
    • leu
    • Leucinum
    • Leucina
    • L-Norvaline, 4-methyl-
    • LEUCINE, L-
    • FEMA No. 3297
    • (S)-2-Amino-4-methylvaleric acid
    • L-alpha-Aminoisocaproic acid
    • Leucin [German]
    • Leucine (VAN)
    • (2S)-alpha-leucine
    • L-(+)-Leucine
    • L-(-)-2-Amino-4-methylpentanoic acid
    • L-leucin
    • Leucine [USAN:INN]
    • Leucinum [INN-Latin]
    • Leucina [INN-Spanish]
    • Leucina [Latin,Spanish]
    • Valeric acid, 2-amino-4-methyl-, (S)-
    • AI3-08899
    • 2-amino-4-methylvaleric acid
    • NSC 46709
    • Pentanoic acid, 2-amino-4-methyl-, (S)-
    • 2-Amino-4-methylpentanoic acid, (S)-
    • UNII-GMW67QNF9C
    • GMW67QNF9C
    • L-Leuzin
    • Leucine, l
    • 2-Amino-4-methylvaleric acid (L)
    • EINECS 200-522-0
    • 2-Amino-4-methylpentanoic acid (L)
    • MFCD00002617
    • NSC-46709
    • Leucine (L-Leucine)
    • CHEBI:15603
    • (2S)-alpha-2-amino-4-methylvaleric acid
    • HSDB 7799
    • CHEMBL291962
    • DTXSID9023203
    • L-Leucine, labeled with tritium
    • EC 200-522-0
    • Leucinum (INN-Latin)
    • Leucina (INN-Spanish)
    • Leucina (Latin,Spanish)
    • LEUCINE (II)
    • LEUCINE [II]
    • LEUCINE (MART.)
    • LEUCINE [MART.]
    • L-Leu
    • alpha-Aminoisocaproic acid
    • Leuzin
    • Hleu
    • LEUCINE (EP MONOGRAPH)
    • LEUCINE [EP MONOGRAPH]
    • LEUCINE (USP MONOGRAPH)
    • LEUCINE [USP MONOGRAPH]
    • Norvaline, 4-methyl-
    • (2S)-2-amino-4-methylpentanoate
    • L-a-Aminoisocaproic acid
    • L-Leucine, Non-animal origin
    • NSC9252
    • Pentanoic acid, 2-amino-4-methyl-
    • LeuOH
    • 1lan
    • 1usk
    • 3h-l-leucine
    • L-2-Amino-4-methylpentanoic acid
    • (L)-leucine
    • .alpha.-Amino-.gamma.-methylvaleric acid
    • (3H)Leucine
    • H-Leu
    • L-Leucine, USP
    • Leucine (USP)
    • L-a-Aminoisocaproate
    • 21675-61-6
    • Leucine (H-3)
    • 4-methyl-L-Norvaline
    • L-Leu-OH
    • (2S)-2-amino-4-methyl-pentanoic acid
    • L-Leucine (Standard)
    • H-Leu-OH USP grade
    • L-Leucine-13C6?
    • 1f2o
    • starbld0005460
    • L-Leucine (JP18)
    • L-alpha-Aminoisocaproate
    • LEUCINE [VANDF]
    • LEUCINE [HSDB]
    • LEUCINE [USAN]
    • LEUCINE [INN]
    • LEUCINE [MI]
    • L-LEUCINE [FCC]
    • L-LEUCINE [JAN]
    • L-LEUCINE [FHFI]
    • LEUCINE [WHO-DD]
    • bmse000042
    • bmse000920
    • L-Leucine, 99%, FG
    • SCHEMBL3889
    • NCIStruc1_001860
    • NCIStruc2_000010
    • iso-C4H9CH(NH2)COOH
    • L-LEUCINE [USP-RS]
    • 2-Amino-4-methyl-valeric acid
    • DTXCID903203
    • GTPL3312
    • L-.alpha.-Aminoisocaproic acid
    • (S)-2-Amino-4-methylvalerate
    • Norvaline, 4-methyl-, (L)-
    • HY-N0486R
    • (S)-2-Amino-4-methylpentanoate
    • IS_LEUCINE-5,5,5-D3
    • Pharmakon1600-01301005
    • HY-N0486
    • NCI46709
    • STR01720
    • L-Leucine, Vetec(TM), 98.5%
    • BDBM50219348
    • CCG-37658

  • Applications

    L-Leucine (CAS 61-90-5) is an essential branched-chain amino acid that drives muscle protein synthesis and nitrogen balance, therefore it is widely incorporated into sports nutrition formulas to trigger anabolism, curb catabolism and accelerate post-exercise recovery; in pharmaceuticals it acts as a tablet lubricant and compressibility enhancer, a stabilizer in dry-powder inhalation products, a component of parenteral nutrition solutions and an agent capable of stimulating growth-hormone release; in food technology and animal feed it is added to optimize amino-acid profiles, promote growth and improve feed conversion ratios; in biotechnology it functions as a key nutrient in cell-culture media facilitating recombinant protein production; while in cosmetics it nourishes the skin, reinforces the protective barrier and diminishes the appearance of wrinkles by activating the mTOR pathway and safeguarding collagen integrity.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 0.8
    methanol 3.0
    isopropanol 0.66
    water 13.32
    ethyl acetate 0.45
    n-propanol 0.43
    acetone 0.24
    n-butanol 0.21
    acetonitrile 0.25
    DMF 0.47
    toluene 0.2
    isobutanol 0.52
    1,4-dioxane 0.36
    methyl acetate 0.53
    THF 1.92
    2-butanone 0.38
    n-pentanol 0.44
    sec-butanol 0.59
    n-hexane 0.11
    ethylene glycol 10.25
    NMP 13.69
    cyclohexane 0.07
    DMSO 5.85
    n-butyl acetate 1.39
    n-octanol 1.08
    chloroform 0.58
    n-propyl acetate 0.43
    acetic acid 9.55
    dichloromethane 0.44
    cyclohexanone 1.59
    propylene glycol 7.19
    isopropyl acetate 0.51
    DMAc 3.28
    2-ethoxyethanol 2.3
    isopentanol 0.49
    n-heptane 0.19
    ethyl formate 0.61
    1,2-dichloroethane 0.27
    n-hexanol 2.27
    2-methoxyethanol 2.68
    isobutyl acetate 0.52
    tetrachloromethane 0.6
    n-pentyl acetate 1.07
    transcutol 6.22
    n-heptanol 2.1
    ethylbenzene 0.37
    MIBK 0.63
    2-propoxyethanol 6.99
    tert-butanol 1.79
    MTBE 0.46
    2-butoxyethanol 4.78
    propionic acid 3.7
    o-xylene 0.67
    formic acid 24.12
    diethyl ether 0.09
    m-xylene 0.65
    p-xylene 0.53
    chlorobenzene 0.36
    dimethyl carbonate 0.43
    n-octane 0.11
    formamide 6.39
    cyclopentanone 2.4
    2-pentanone 0.28
    anisole 0.61
    cyclopentyl methyl ether 0.8
    gamma-butyrolactone 4.72
    1-methoxy-2-propanol 2.06
    pyridine 0.48
    3-pentanone 0.31
    furfural 7.92
    n-dodecane 0.09
    diethylene glycol 14.91
    diisopropyl ether 0.19
    tert-amyl alcohol 2.5
    acetylacetone 1.17
    n-hexadecane 0.09
    acetophenone 1.61
    methyl propionate 0.5
    isopentyl acetate 2.16
    trichloroethylene 0.94
    n-nonanol 1.08
    cyclohexanol 0.84
    benzyl alcohol 1.4
    2-ethylhexanol 2.15
    isooctanol 2.2
    dipropyl ether 0.41
    1,2-dichlorobenzene 0.92
    ethyl lactate 2.07
    propylene carbonate 3.51
    n-methylformamide 0.9
    2-pentanol 0.3
    n-pentane 0.04
    1-propoxy-2-propanol 4.73
    1-methoxy-2-propyl acetate 3.16
    2-(2-methoxypropoxy) propanol 8.48
    mesitylene 0.76
    ε-caprolactone 2.55
    p-cymene 1.23
    epichlorohydrin 1.52
    1,1,1-trichloroethane 0.49
    2-aminoethanol 6.18
    morpholine-4-carbaldehyde 5.82
    sulfolane 19.44
    2,2,4-trimethylpentane 0.19
    2-methyltetrahydrofuran 1.15
    n-hexyl acetate 1.55
    isooctane 0.15
    2-(2-butoxyethoxy)ethanol 6.64
    sec-butyl acetate 0.52
    tert-butyl acetate 1.26
    decalin 0.24
    glycerin 20.03
    diglyme 6.52
    acrylic acid 5.96
    isopropyl myristate 0.84
    n-butyric acid 1.71
    acetyl acetate 0.84
    di(2-ethylhexyl) phthalate 3.82
    ethyl propionate 0.49
    nitromethane 2.67
    1,2-diethoxyethane 0.53
    benzonitrile 0.84
    trioctyl phosphate 2.38
    1-bromopropane 0.11
    gamma-valerolactone 4.62
    n-decanol 0.88
    triethyl phosphate 1.98
    4-methyl-2-pentanol 0.69
    propionitrile 0.19
    vinylene carbonate 2.57
    1,1,2-trichlorotrifluoroethane 11.63
    DMS 1.7
    cumene 0.7
    2-octanol 1.2
    2-hexanone 0.44
    octyl acetate 1.27
    limonene 1.25
    1,2-dimethoxyethane 1.15
    ethyl orthosilicate 1.76
    tributyl phosphate 1.99
    diacetone alcohol 4.51
    N,N-dimethylaniline 1.13
    acrylonitrile 0.41
    aniline 0.5
    1,3-propanediol 2.72
    bromobenzene 0.33
    dibromomethane 0.31
    1,1,2,2-tetrachloroethane 1.16
    2-methyl-cyclohexyl acetate 3.35
    tetrabutyl urea 2.62
    diisobutyl methanol 1.61
    2-phenylethanol 3.41
    styrene 0.22
    dioctyl adipate 1.66
    dimethyl sulfate 2.34
    ethyl butyrate 1.0
    methyl lactate 2.75
    butyl lactate 3.04
    diethyl carbonate 0.88
    propanediol butyl ether 5.98
    triethyl orthoformate 1.32
    p-tert-butyltoluene 1.32
    methyl 4-tert-butylbenzoate 6.5
    morpholine 0.46
    tert-butylamine 0.72
    n-dodecanol 0.73
    dimethoxymethane 0.41
    ethylene carbonate 1.49
    cyrene 14.54
    2-ethoxyethyl acetate 1.73
    2-ethylhexyl acetate 1.62
    1,2,4-trichlorobenzene 1.48
    4-methylpyridine 0.37
    dibutyl ether 0.24
    2,6-dimethyl-4-heptanol 1.61
    DEF 0.44
    dimethyl isosorbide 16.51
    tetrachloroethylene 1.55
    eugenol 7.48
    triacetin 3.12
    span 80 8.82
    1,4-butanediol 2.34
    1,1-dichloroethane 0.18
    2-methyl-1-pentanol 0.97
    methyl formate 1.12
    2-methyl-1-butanol 0.56
    n-decane 0.11
    butyronitrile 0.15
    3,7-dimethyl-1-octanol 1.51
    1-chlorooctane 0.34
    1-chlorotetradecane 0.22
    n-nonane 0.1
    undecane 0.09
    tert-butylcyclohexane 0.29
    cyclooctane 0.09
    cyclopentanol 1.71
    tetrahydropyran 0.21
    tert-amyl methyl ether 0.68
    2,5,8-trioxanonane 9.49
    1-hexene 0.16
    2-isopropoxyethanol 2.08
    2,2,2-trifluoroethanol 7.13
    methyl butyrate 0.58

    Scent© AI

1 4

IFRA standard 51

Recommendation
No restriction
Maximum acceptable concentrations in the finished product (%)
Category 1
Products applied to the lips
 No restriction Category 7A
Rinse-off products applied to the hair with some hand contact
 No restriction
Category 2
Products applied to the axillae
 No restriction Category 7B
Leave-on products applied to the hair with some hand contact
 No restriction
Category 3
Products applied to the face/body using fingertips
 No restriction Category 8
Products with significant anogenital exposure
 No restriction
Category 4
Products related to fine fragrance
 No restriction Category 9
Products with body and hand exposure, primarily rinse off
 No restriction
Category 5A
Body lotion products applied to the body using the hands (palms), primarily leave on
 No restriction Category 10A
Household care products with mostly hand contact
 No restriction
Category 5B
Face moisturizer products applied to the face using the hands (palms), primarily leave on
 No restriction Category 10B
Household care products with mostly hand contact, including aerosol/spray products (with potential leave-on skin contact)
 No restriction
Category 5C
Hand cream products applied to the hands using the hands (palms), primarily leave on
 No restriction Category 11A
Products with intended skin contact but minimal transfer of fragrance to skin from inert substrate without UV exposure
 No restriction
Category 5D
Baby Creams, baby Oils and baby talc
 No restriction Category 11B
Products with intended skin contact but minimal transfer of fragrance to skin from inert substrate with potential UV exposure
 No restriction
Category 6
Products with oral and lip exposure
 No restriction Category 12
Products not intended for direct skin contact, minimal or insignificant transfer to skin
 No restriction