Folic

Folic acid and its derivatives (mostly the tri-and heptaglutamyl peptides) are widespread in nature. It is a specific growth ctor for certain micro-organisms, but in animals the intestinal bacteria provide the small quantities needed for growth. The coenzyme forms are actually... 

The action of the sulphonamides is antagonized by p-aminobenzoic acid and they act by inhibiting the uptake and utilization of 1-aminobenzoic acid by bacterial cells, which require this as a precursor of folic acid. 

The Schiff base obtained is converted in good yield (60 to 80%) to amines by the action of Raney Ni (209). This reductive condensation provides a good synthetic method and was used to prepare thiazole analogs (62) of folic acid (Scheme 43) (210). These Schiff bases under... 

Bacteria require p-aminobenzoic acid to biosyn thesize folic acid a growth factor Structurally sul fanilamide resembles p-aminobenzoic acid and is mistaken for it by the bacteria Folic acid biosynthesis IS inhibited and bacterial growth is slowed suffi ciently to allow the body s natural defenses to effect a cure Because animals do not biosynthesize folic acid but obtain it in their food sulfanilamide halts the growth of bacteria without harm to the host... 

At various times, antivitamin factors specific to vitamin folic acid, and choline have been reported. However, it is uncertain whether these are tme antimetaboHtes or if they may result from metaboHc interrelationships with other dietary constituents. 

En2ymatic reduction of folic acid leads to the 7,8-dihydrofolic acid (H2 folate) (2), a key substance in biosynthesis. Further reduction, cataly2ed by the en2yme dihydrofohc acid reductase, provides (65)-5,6,7,8-tetrahydrofohc acid (H folate) (3). The folate (3) is the key biological intermediate for the formation of other folates (4—8) (Table 2). 

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