The Pteroylglutamic Acid Family and Related Peptides

Naturally occurring peptides of the pteroylglutamic acid (PGA) family and of folinic acid, such as p-aminobensoylpolyglutamic acid, are very closely related, by structure as well as by origin, and they may be considered as belonging to the same group. We will therefore discuss them together. 

These peptides are widely distributed in higher animals, plants, and microorganisms. They act as growth and antianemic factors, important physiological activities which led to their discovery. There is an excellent 

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