Dextrose
grape sugar, dextroglucose, C6H12O or C.HO (OH). Dextrose occurs along with levulose in grapes and other sweet fruits, also in honey and in the urine of diabetic patients. It can be produced by the action of dilute sulphuric acid on cane sugar, starch, cellulose, etc. It can be best obtained by boiling for several hours 50 parts of starch with dilute sulphuric acid (100 parts of water to five parts of H2SO4). The solution is then neutralized with chalk, filtered, boiled with animal charcoal to remove traces of color, and then evaporated carefully to dryness, forming an amorphous mass which contains about 60 per cent. of dextrose, the remainder being chiefly dextrin. Pure dextrose can be obtained by crystallization from alcohol. It turns polarized light to the right, and dissolves lime, baryta, oxide of lead, etc.
Dextrose reduces an alkaline solution of cupric sulphate, giving a red precipitate of Cu2O on heating. It reduces ferric salts to ferrous salts. Dextrose tastes much less sweet than ordinary cane sugar. By the action of sodium amalgam on dextrose it is converted into mannite, C6H14O6.