A New Synthesis of Pteridines

Abstract

THERE is a growing biological interest in derivatives of pteridine (I: R1, R2, R3, R4 = H) as a source of antagonists for folic acid (I: R1 = OH; R2 = NH2 ; R4 = H; R3 = CH2.NH.C6H4.CO.NHCH(COOH): CH2CH2COOH-p), since this vitamin plays an important part in the growth of certain bacteria and normal and malignant tissue. Thus, Hertz1 has reported that abnormal growth in the chick genital tract evoked by stilbA"strol was inhibited by methyl folio acid (I: R1 = OH; R2 = NH2; R4 = CH3; R3 = CH2.NH.C6H4.CO.NHCH(COOH).CH2CH2-COOH-p), which is a powerful antagonist (Martin et al.2), an effect which was reversed by giving folic acid. Little et al.3 and Woll4 have reported inhibition of growth of the Rous chicken sarcoma by means of antagonists, and Bass and Freeman5 found that the inhibition of a lymphoma (lymphoma 6C3HED) in the mouse by mustard gas was to some extent prevented by giving folic acid. Meyer6 claims a favourable clinical effect in acute leukaemia with methylpteroic acid (I: R1 = OH; R2 = NH2; R4 = H; R3 = CH2.N(CH3)C6H4COOH-p). Other antagonists of simple structure are reported by Daniel et al.7.