Compounds of Formula I and Formula IA are inhibitors of dihydrofolate reductase and are suitable for use in compositions and methods for dihydrofolate reductase inhibition or, more specifically, treatment of a fungal infection, a bacterial infection or a protozoal infection, and, in specific embodiments, treatment of a fungal infection caused by C. albicans or C. glabrata:wherein R, R1, R2, R3, R4, A, B, E, V, W, X, Y and Z are as defined herein.