title: C5H9NO3
text: # C5H9NO3
  
  The molecular formula $C_5H_9NO_3$ (molar mass : 131.13 g/mol) may refer to:
  
  * Aminolevulinic acid, first compound in the porphyrin synthesis pathway
  * Glutamate-1-semialdehyde
  * Glutamate-5-semialdehyde
  * Hydroxyproline
  