A cluster of three vinegar molecules (acetic acid)

Citric acid

https://upload.wikimedia.org/wikipedia/commons/thumb/c/c5/Zitronens%C3%A4ure_-_Citric_acid.svg/150px-Zitronens%C3%A4ure_-_Citric_acid.svg.png

Acetic acid

 https://upload.wikimedia.org/wikipedia/commons/thumb/0/08/Acetic-acid-2D-skeletal.svg/110px-Acetic-acid-2D-skeletal.svg.png

 

EDTA

 

 

 

Heparine