Synonyms: alpha-Keto-(3-methyl-13C)-butyric-4-13C,3-d acid sodium; alpha-Ketoisovaleric-(3-methyl-13C),4-13C-3-d acid sodium salt; 2-Ketoisovaleric-(3-methyl-13C),4-13C,3-d acid sodium salt; 3-Methyl-13C-2-oxobutanoic-4-13C,d acid sodium salt; Sodium alpha-ketoisovalerate-(3-methyl-13C),4-13C,3-d...