replacement of the glutamic acid ( glu ) moiety in methotrexate ( mtx ) and aminopterin ( amt ) by 2-amino-4-phosphonobutyric acid ( apba ) and ornithine ( orn ) has been found to give analogs that retain the ability to inhibit dihydrofolate reductase ( dhfr ) while also displaying high activity against folylpolyglutamate synthetase ( fpgs ) .
C0061472
glu
C0002520
amino