Tryptophan

• L-Tryptophan is a neutral, genetically coded amino acid.
• It is dietarily essential (indispensable) for animals & humans.
• L-Tryptophan is a precursor for serotonin and nicotinic acid.
• Microbial metabolites (formed within the gastrointestinal tract) of tryptophan are skatole (3-methyl-indole) and indole. Skatole and indole are primary constituents of "fecal odor".

Symbol / Abbreviation

trp

Molecular formula

C₁₁H₁₂N₂O₂

Structural formula

              H                             
              |                             
 Ph-----C-CH2-C-COOH          Ph-----C-CH3     Ph-----CH     
   \   ||     |                 \   ||           \   ||    
    \   CH    NH2                \   CH           \   CH   
     \ /                          \ /              \ /
      NH                           NH               NH

      Tryptophan                Skatole           Indole
                            (microbial metabolites of tryptophan)

 [Ph represents a phenyl group.]

 

Molecular weight

204.23

pK1 a-COOH	pK2 a-NH3	pKa R-group
2.4	9.4	--

Isoelectric point (pH)

5.89

CAS Registry Number

73-22-3