C5H9NO3
# 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
