| abstract |
ABSTRACT OF THE DISCLOSURE Pteridine compounds of the formula wherein R1 and R2 taken alone are, independently of each other, hydrogen, alkyl having from 1 to 6 carbon atoms, or benzyl, or wherein R1 and R2, taken together with the nitrogen atom to which they are bound, form a five- or six-membered heterocyclic ring system or such a ring containing one or two further hetero atoms, or wherein R1 and R2 together with the nitrogen are |