1. C00163 compound   Propionic acid
                      Propanoate
                      Propionate
                      Propanoic acid

2. C01198 compound   3-(2-Hydroxyphenyl)propionic acid
                      Melilotate
                      2-Hydroxyphenylpropanoate
                      3-(2-Hydroxyphenyl)propanoate
                      3-(2-Hydroxyphenyl)propionate

3. C01744 compound   3-(4-Hydroxyphenyl)propionic acid
                      Phloretate
                      Phloretic acid

4. C03680 compound   4-Imidazolone-5-propionic acid
                      4-Imidazolone-5-propanoate
                      4,5-Dihydro-4-oxo-5-imidazolepropanoate

5. C04022 compound   S-Dimethylsulfonium propionic acid
                      DMPT
                      DMSP
                      Dimethylpropiothetin
                      S,S-Dimethyl-beta-propiothetin

6. C05629 compound   3-Phenyl-propionic acid
                      Phenylpropanoate
                      3-Phenylpropanoic acid

7. C08276 compound   3-(Methylthio)propionic acid
                      3-Methylthiopropionate

8. C11020 compound   2-(2,4-Dichlorophenoxy)propionic acid
                      Dichlorprop
                      2,4-DP

9. C11491 compound   2-(2-Naphthoxy)propionic acid
                      NOP
                      2-(2-Naphthalenyloxy)propanoic acid

10. C13701 compound   2-(p-Chlorophenoxy)propionic acid
                      CPP

11. C00082 compound   (S)-2-Amino-3-(p-hydroxyphenyl)propionic acid
                      L-Tyrosine
                      (S)-3-(p-Hydroxyphenyl)alanine

12. C01536 compound   2-Amino-3-(p-hydroxyphenyl)propionic acid
                      Tyrosine
                      3-(p-Hydroxyphenyl)alanine

13. C06420 compound   (R)-2-Amino-3-(p-hydroxyphenyl)propionic acid
                      D-Tyrosine
                      (R)-3-(p-Hydroxyphenyl)alanine

14. C00135 compound   (S)-alpha-Amino-1H-imidazole-4-propionic acid
                      L-Histidine

15. C00768 compound   alpha-Amino-1H-imidazole-4-propionic acid
                      Histidine

16. C06419 compound   (R)-alpha-Amino-1H-imidazole-4-propionic acid
                      D-Histidine

17. C11492 compound   2-(2-Naphthoxy)propionic acid methyl ester
                      NOPM

18. C00078 compound   (S)-alpha-Amino-beta-(3-indolyl)-propionic acid
                      L-Tryptophan

19. C00806 compound   alpha-Amino-beta-(3-indolyl)-propionic acid
                      Tryptophan

20. C13672 compound   (S)-2-Amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid
                      (S)-AMPA

21. C04871 compound   (RS)-2-[4-(3-Chloro-5-(trifluoromethyl-2-pyridyloxy)phenoxy]- propionic acid