1 5HY [(4r)-2,5-dioxoimidazolidin-4-yl]acetic acid 1.000 2 A1LUZ 2-[2,4-bis(oxidanylidene)-1,3-thiazolidin-5-ylidene]ethanoic acid 0.833 3 IZC 2h-imidazol-4-ylacetic acid 0.818 4 O2U [(3s)-1-hydroxy-2,5-dioxopyrrolidin-3-yl]acetic acid 0.769