Folinic polyglutamates

It is of interest that folic or folinic polyglutamates are required for the conversion of serine to glycine in a cell-free enzyme preparation from a Clostridium strain which apparently cannot utilize monoglutamates, and evidence for the natural occurrence of M -formyltetrahydropteroyltrigluta-mate has been reported . Other bound forms of folinic acid appear to exist. ... 

The antimetabolite, raltitrexed, is a folate analogue and is a potent and specific inhibitor of the enzyme thymidylate synthase. Inhibition of this enzyme ultimately interferes with the synthesis of deoxyribonucleic acid (DNA) leading to cell death. The intracellular polyglutamation of raltitrexed leads to the formation within cells of even more potent inhibitors of thymidylate synthase. Folate (methylene tetrahydrofolate) is a co-faetor required by thymidylate synthase and therefore theoretically folinic acid or folic acid may interfere with the aetion of raltitrexed. Clinieal interaction studies have not yet been undertaken to confirm these predieted inter-aetions. ... 

Rosenblatt DS (1978) Folinic acid inhibits the accumulation of methotrexate polyglutamates by cultured human cells. Clin Res 26 875 A Rust S (1954) Uber allergische Reaktionen bei Vitamintherapie. Z Hautkr 17 317-319 Saif N, Faivre M, Barral C, Lery N (1975) Chocs apres la vitamine Bi2- Bull Med Leg Toxicol Med 18 65-67... 

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