2-Keto-L-gulonic acid 2-Oxo-l-gulonic acid 3-keto-L-Gulonic acid 526-98-7 EINECS 208-403-5 Idonic acid, 2-keto-, L- L-Xylohexulosonic acid L-xylo-2-Hexulosonic acid L-xylo-Hex-2-ulosonic acid