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Clinical pharmacy PharmD program                     Third level                          Phytochemistry-1 (PG-504)


              ▪  Concentrated  sulfuric  acid  removes  the  elements  of  water  form  sugar

                molecules to give carbon (charcoal).

              ▪  Nitric acid oxidizes aldoses into dicarboxylic acids (saccharic acids).

              ▪  Many tests used for the identification and analysis of carbohydrates are based

                upon  the  production  of  strongly  colored  materials  by  reaction  of  the  acid

                degradation products with a number of phenols, aromatic amines and certain

                aliphatic amino acids.  Examples are:

                   Substance used              Reaction Name                Test for :



                       -Naphthol /H 2SO 4      Molisch’s test              All carbohydrates


                       Resorcinol  /HCl            Seliwanoff’s test        Ketose



                       Urcinol  / HCl              Bial’s test              Pentose










































                                                 Condensation product unstable
                                                   Purple / deep violet color
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