2024-05-20by admin0

L-isoleucine structural formula

Structural formula

Business number 01HE
Molecular formula C6H13NO2
Molecular weight 131.17

α-amino-β-methylvaleric acid,

L-isofluorescent amino acid,


L-2-Amino-3-methylpentanoic acid,

(2S,3S)2-Amino-3-methylpentanoic acid,

L-a-Amino-b-methylvaleric Acid,

L-2-Amino-3-methylvaleric Acid,

nutritional supplements,


Numbering system

CAS number:73-32-5

MDL number:MFCD00064222

EINECS number:200-798-2

RTECS number:NR4705000

BRN number:1721792

PubChem number:24902116

Physical property data

1. Properties: White crystal flakes or crystalline powder, which can form rhombus leaves or flake crystals when crystallized in ethanol. Odorless, slightly bitter. 2. Density (g/mL, 25/4℃): 1.035

3. Relative vapor density (g/mL, air=1): Uncertain

4. Melting point (ºC): 284 (dec.)(lit.)

5. Boiling point (ºC, normal pressure): Uncertain

6. Boiling point (ºC, 5.2 kPa): Uncertain

7. Refractive index: 40.5 ° (C=4, 6mol/L HCl)

8. Flash point (ºC): 168-170

9. Specific rotation (º): 41 º (c=4, 6N HCl)

10. Autoignition point or ignition temperature (ºC): Uncertain

11. Vapor pressure (kPa, 25 ºC): Uncertain

12. Saturated vapor pressure (kPa, 60 ºC): Uncertain

13. Heat of combustion (KJ/mol): Uncertain

14. Critical temperature (ºC): Uncertain

15. Critical pressure (KPa): Uncertain

16. Log value of oil-water (octanol/water) partition coefficient : Uncertain

17. Explosion upper limit (%, V/V): Uncertain

18. Explosion lower limit (%, V/V): Uncertain

19. Solubility: Solubility in water is 41.2 g/L (25°C), insoluble in hot alcohol (0.13% at 80°C) and hot acetic acid, insoluble in ether

Toxicological data

Acute toxicity: rat abdominal LD50: 6822 mg/kg; mutagenicity: human lymphocyte sister chromatid exchange test system: 10 mg/L;

Ecological data


Molecular structure data

1. Molar refraction��: 34.86

2. Molar volume (cm3/mol): 126.6

3. Isotonic specific volume (90.2K): 316.4

4. Surface tension (dyne/cm): 39.0

5. Polarizability (10-24cm3): 13.82

Compute chemical data

1. Hydrophobic parameter calculation reference value (XlogP): -1.7

2. Number of hydrogen bond donors: 2

3. Number of hydrogen bond acceptors: 3


4. Number of rotatable chemical bonds: 3

5. Topological molecular polar surface area (TPSA): 63.3

6. Number of heavy atoms: 9

7. Surface charge: 0

8. Complexity: 103

9. Number of isotope atoms: 0

10. Determine the atomic stereocenter Number: 2

11. Number of uncertain atomic stereocenters: 0

12. Number of determined chemical bond stereocenters: 0

13. Uncertain chemical bonds Number of stereocenters: 0

14, Number of covalent bond units: 1

Properties and stability

1. Found in flue-cured tobacco leaves and burley tobacco leaves.

2. The L-body has a bitter taste.

Storage method

Sealed packaging in brown glass bottles. Store in a cool, dry place away from light.

Synthesis method

1. It is obtained from sugar, ammonia and D-threonine through fermentation of S. marcescens. Or it can be obtained by using sugar, ammonia and α-aminobutyric acid as raw materials, fermenting it with Pediococcus xanthus or Citrobacter striatum and then refining it.

2. Bacteria culture and fermentation fermentation broth filter the upper liquid oxalic acid, and H2SO4 filters the filtrate for adsorption.

3. Elution, concentration of eluate, distillation under reduced pressure, decolorization, concentration under pressure, distillation, neutralization of ammonia solution, precipitation, purification and crystallization.

4. Dry the finished product of L-isoleucine at 105℃.

5. Tobacco: BU, 22; FC, 21; Synthesis: It can be hydrolyzed and refined from proteins such as corn protein. It can also be synthesized chemically.


Can be used as a nutritional supplement to fortify various foods. It can also be used in medicine as an ingredient in amino acid preparations.


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