4-Aminobenzoic acid (also known as para-aminobenzoic acid or PABA because the two functional groups are attached to the benzene ring across from one another in the para position) is an organic compound with the formula H2NC6H4CO2H. PABA is a white solid, although commercial samples can appear gray. It is slightly soluble in water. It consists of a benzene ring substituted with amino and carboxyl groups. The compound occurs extensively in the natural world.
Folinic acid, also known as leucovorin, is a medication used to decrease the toxic effects of methotrexate and pyrimethamine. It is also used in combination with 5-fluorouracil to treat colorectal cancer and pancreatic cancer, may be used to treat folate deficiency that results in anemia, and methanol poisoning. It is taken by mouth, injection into a muscle, or injection into a vein.
Sulfamethoxazole is an antibiotic. It is used for bacterial infections such as urinary tract infections, bronchitis, and prostatitis and is effective against both gram negative and positive bacteria such as Escherichia coli and Listeria monocytogenes.
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. It is structurally related to the parent bicyclic heterocycle called pteridine. Pterins, as a group, are compounds related to pterin with additional substituents. Pterin itself is of no biological significance.
Pyrimethamine, sold under the brand name Daraprim among others, is a medication used with leucovorin to treat the parasitic diseases toxoplasmosis and cystoisosporiasis. It is also used with dapsone as a second-line option to prevent Pneumocystis jiroveci pneumonia in people with HIV/AIDS. It was previously used for malaria but is no longer recommended due to resistance. Pyrimethamine is taken by mouth.
GTP cyclohydrolase I (GTPCH) (EC 3.5.4.16) is a member of the GTP cyclohydrolase family of enzymes. GTPCH is part of the folate and biopterin biosynthesis pathways. It is responsible for the hydrolysis of guanosine triphosphate (GTP) to form 7,8-dihydroneopterin triphosphate (7,8-DHNP-3'-TP, 7,8-NH2-3'-TP).
Sulfanilamide is a sulfonamide antibacterial drug. Chemically, it is an organic compound consisting of an aniline derivatized with a sulfonamide group. Powdered sulfanilamide was used by the Allies in World War II to reduce infection rates and contributed to a dramatic reduction in mortality rates compared to previous wars. Sulfanilamide is rarely if ever used systemically due to toxicity and because more effective sulfonamides are available for this purpose. Modern antibiotics have supplanted sulfanilamide on the battlefield; however, sulfanilamide remains in use today in the form of topical preparations, primarily for treatment of vaginal yeast infections mainly vulvovaginitis which is caused by Candida albicans.
Sulfacetamide is a sulfonamide antibiotic.
Dihydropteroate is an important intermediate in folate synthesis. It is a pterin created from para-aminobenzoic acid (PABA) by the enzyme dihydropteroate synthase.
Tetrahydrofolic acid (THFA), or tetrahydrofolate, is a folic acid derivative.
Sulfadimethoxine is a long-lasting sulfonamide antimicrobial medication used in veterinary medicine. It is used to treat many infections, including respiratory, urinary tract, enteric, and soft tissue infections and can be given as a standalone or combined with ormetoprim to broaden the target range. Like all sulfamides, sulfadimethoxine inhibits bacterial synthesis of folic acid by acting as a competitive inhibitor against PABA. It is the most common drug prescribed to dogs who have coccidiosis.
Antifolates are a class of antimetabolite medications that antagonise (that is, block) the actions of folic acid (vitamin B9). Folic acid's primary function in the body is as a cofactor to various methyltransferases involved in serine, methionine, thymidine and purine biosynthesis. Consequently, antifolates inhibit cell division, DNA/RNA synthesis and repair and protein synthesis. Some such as proguanil, pyrimethamine and trimethoprim selectively inhibit folate's actions in microbial organisms such as bacteria, protozoa and fungi. The majority of antifolates work by inhibiting dihydrofolate reductase (DHFR).
The enzyme dihydroneopterin aldolase catalyzes the chemical reaction
In enzymology, an aminodeoxychorismate synthase is an enzyme that catalyzes the chemical reaction
In enzymology, a dihydrofolate synthase is an enzyme that catalyzes the chemical reaction
In enzymology, a 2-amino-4-hydroxy-6-hydroxymethyldihydropteridine diphosphokinase is an enzyme that catalyzes the chemical reaction
Dihydropteroate synthase inhibitors are drugs that inhibit the action of dihydropteroate synthase. They include sulfonamides, dapsone, and para-aminosalicylic acid.
Phytoene synthase is a transferase enzyme involved in the biosynthesis of carotenoids. It catalyzes the conversion of geranylgeranyl pyrophosphate to phytoene. This enzyme catalyses the following chemical reaction
Geranyl diphosphate 2-C-methyltransferase is an enzyme with systematic name S-adenosyl-L-methionine:geranyl-diphosphate 2-C-methyltransferase. This enzyme catalyses the following chemical reaction
Ketoacyl synthases (KSs) catalyze the condensation reaction of acyl-CoA or acyl-acyl ACP with malonyl-CoA to form 3-ketoacyl-CoA or with malonyl-ACP to form 3-ketoacyl-ACP. This reaction is a key step in the fatty acid synthesis cycle, as the resulting acyl chain is two carbon atoms longer than before. KSs exist as individual enzymes, as they do in type II fatty acid synthesis and type II polyketide synthesis, or as domains in large multidomain enzymes, such as type I fatty acid synthases (FASs) and polyketide synthases (PKSs). KSs are divided into five families: KS1, KS2, KS3, KS4, and KS5.
