THFA, tetrahydrofolic acid

The folate pathway is one in which selective chemotherapeutic intervention has been very successful, and a number of drugs acting through this pathway are in current use. This is because of the fact that mammals receive FA from their diet and convert it into dihydrofolic acid (DHFA) and tetrahydrofolic acid (THFA), which give rise to folate cofactors. The bacteria and protozoans, on the other hand can not effectively utilize FA to get their requirements of DHFA and THFA. Consequently, these organisms synthesize DHFA de novo (for details, see Chapter 13). Further the affinity of the enzymes involved from different sources (mammalian, bacterial and protozoan) for different classes of inhibitors is quite different, which has resulted in the development of drugs with selective action. 

Tetrahydrofolic acid dihydrochloride 2H2O (THFA, 6S- or 6RS- 5,6,7,8-tetrahydrofolic acid 2HC1 2H2O, 5,6,7,8-tetrahydropteroyl-L-glutamic acid 2HC1 2H2O) [135-16-0] M... 

In fact, sulphanilamdie gives rise to a false metabolite that eventually prevents its ultimate conversion to tetrahydrofolic acid (THFA) as shown below ... 

A cell-free extract of S. timofaaens convened cytosine monc dtosphate (42, CMP) and formaldehyde to 34 in the presence of tetrahydrofolic acid (THFA) and (83). 2-Mercapttoethanol stimulated this activity, artd could replace iiDn. albeit at a somewhat reduced activity. The product of a large-scale incubation that included [iiCHjJparafonnaldehyde was unequivocally characterized by ultiaviolet/visible (UV/vis) and lie nuclear magnetic resonance (NMR) spectroscopies. 

---