inhibitory potency was in the ascending order methotrexate less than 5-deazamethotrexate less than 5-deazaaminopterin less than aminopterin less than 5-alkyl ( methyl or ethyl ) analogues of 5-deazaaminopterin and 5-deazamethotrexate ( the ethyl analogues were 2-fold more inhibitory than the methyl analogues ) .
C0025677
methotrexate
C0002583
aminopterin