If the definition of saccharides (or sugars) is rather unclear, specialists usually agree on saying that chemists can describe saccharides as structures derived from chiral entities bearing hydroxyl or diversely substituted hydroxyl, incorporating in this family molecules with nitrogen, sulphur or even alkyl, inspired by a Fischer-type skeleton. Because this is only limited by our imagination, chemists may generally say that saccharide derivatives should look like saccharides (joke). However, we agree on an unanimous definition for “hexoses”: simple sugars containing six carbon atoms and the equivalent of one molecule of water per carbon atom (C,H2O)6 or C6H12O6 in their general formula. All D-hexoses are naturally occurring, with the exception of D-altrose, the major ones being D-glucose, D-galactose, D-mannose and D-fructose