1 FOO (3e)-4-{3-hydroxy-2-methyl-5-[(phosphonooxy)methyl]pyridin-4-yl}-2-iminobut-3-enoic acid 1.000 2 AN7 (3e)-4-{3-hydroxy-2-methyl-5-[(phosphonooxy)methyl]pyridin-4-yl}-2-oxobut-3-enoic acid 0.909 3 77E (4r)-4-amino-6-{3-hydroxy-2-methyl-5-[(phosphonooxy)methyl]pyridin-4-yl}hexanoic acid 0.760 4 PLR (5-hydroxy-4,6-dimethylpyridin-3-yl)methyl dihydrogen phosphate 0.714