D. Fish, H. Blumenthal
1966
Citations
0
Influential Citations
4
Citations
Journal
Methods in Enzymology
Abstract
Publisher Summary This chapter reveals that the D-glucarie (saccharic) acid, when isolated as the potassium acid salt following the oxidation of D-glucose with nitric acid, is contaminated with small amounts of potassium acid oxalate and potassium acid D-tartrate. Some commercial samples of potassium acid D-glucarate vary considerably in their properties, such as by having 26% potassium instead of the 15.8% required by theory. Although recrystallization of the potassium acid salt from water yields a product whose potassium content is close to theory, other criteria of purity are needed, especially as boiling water can lactonize potassium acid glucarate. Although crystalline 1,4- and 6,3-1actones of D-glucaric acid with sharp melting points can be prepared, potassium acid glucarate itself does not have a usable melting point and free glucaric acid is not convenient to prepare. The cyclohexylamine salts can conveniently be used to purify and to assess the purity of D-glucarate, a substrate for D-glucarate dehydrase. The cyclohexylamine salts of D-glucaric and galactaric (mucic) acids and of four organic acids that could arise as contaminants during preparation of potassium acid glucarate or calcium glucarate—namely, oxalic, D-gluconic, D-glucuronic, and D-tartaric acids, are easily prepared.