Dihydropteroate is a pterin

Pterin

Pterin is a heterocyclic compound composed of a pteridine ring system, with a keto group and an amino group on positions 4 and 2 respectively...

 created from para-aminobenzoic acid (PABA) by the enzyme dihydropteroate synthetase

Dihydropteroate synthetase

Dihydropteroate synthetase is an enzyme classified under . It produces dihydropteroate in bacteria, but it is not expressed in most eukaryotes including humans...

. It is an important intermediate in folate synthesis.
Bacteriostatic agents, such as sulfonamides, target dihydropteroate synthetase. The effect of dihydropteroate synthetase inhibition is comparable to that of dihydrofolate reductase inhibition by trimethoprim, another bacteriostatic agent. Together these two drugs - trimethoprim-sulfamethoxazole [TMP-SMX] - are commonly used to treat recurrent urinary tract, Shigella, Salmonella, and Pneumocystis jivoreci infections.