Folic acid synthesis pathway

The **folic acid synthesis pathway** (also known as the folate biosynthesis or folate metabolism pathway) is a *multistep metabolic route* responsible for the generation and utilization of folate cofactors, which are crucial for **one-carbon metabolism**[1][4][7]. This pathway includes the absorption, conversion, and cellular processing of dietary folates and synthetic folic acid: after absorption and reduction by dihydrofolate reductase, folate derivatives donate one-carbon units needed for the **synthesis of purines, thymidine, and methionine**[1][4][5][7]. In humans, folates must be obtained from diet and are essential for DNA/RNA synthesis, cell division, and methylation reactions vital for gene expression and cellular function[1][3][4][7]. Although mammals cannot synthesize folic acid de novo, many microorganisms (bacteria, parasites) depend on their endogenous folic acid synthesis pathway, which is targeted by antibiotics and antimalarials like sulfonamides and trimethoprim. As a *pathway*, rather than a single molecule or receptor, it comprises several enzymes (e.g., dihydropteroate synthase, dihydrofolate reductase), transporters (e.g., proton-coupled folate transporter, reduced folate carrier), and coenzymes. It is not a specific therapeutic target itself; however, **individual enzymes/steps in the pathway are established therapeutic targets** in cancer, infectious disease, and for preventing neural tube defects[1][3][5]. Crucially, the request refers to a *pathway*, not a molecule, receptor, or gene, making its use as a "target" imprecise or incorrect for pharmacological classification.

Other names

Folate biosynthesis pathwayFolate metabolism pathwayOne-carbon metabolism pathway

Inhibition of dihydrofolate reductase (DHFR) (e.g., methotrexate, trimethoprim) - Inhibition of dihydropteroate synthase (e.g., sulfonamides) - Antifolate antimetabolite activity