Black – Catechu

Synonym                                              :  Katha , Cutch , Khadir Catechu etc .

Biological source                                  :  It consist of dried aquous extracts prepare from 

                                                               the wood of Acacia Catechu and Acacia chundra .

Scientific name                          :  Acacia Catechu  .

Family                                                  :  Leguminosae .

Geographical distribution                       :  It is found in India and in Mayanmar .

Organoleptic / Morphological Evaluation :

i)  Colour                                  -  Light-brown to Black .

ii) Odour                                  -  None  .

iii) Taste                                   -  Very astringent taste  .

iv) Size                         -  About 2.5 to 5 c.m .

v)  Shape                                  -  Cube or irregular fragments of broken cubes or brick

                                                              shaped pieces .

            vi) Extra Features                     -  The cubes as well as brick shaped pieces of Catechu ,

                                                                so the presence of Vegetable debris and break with

                                                                short fracture .

                                                                       The broken pieces are pale , cinnamon is brown

                                                                 colour . It is porous in nature .

Chemical constituents :. Black Catechu contains about 10% of Acacia catechu or

                                       Acacatechin undergoes oxidation in presence of water to form

                                       Catechutannic acid . The other contents of black catechu are

                                       Catechu-red , Quercetin-gum and Quercitrin .

Identificcation Test

( I ) Due to presence of Catechin , black-catechu gives pink or red colour with vanillin and

        hydrochloric acid .

( II )  Lime water when  added with aquous extract of black – catechu gives brown colour

         which turns to red precipitate on standing for sometime .

( III ) Green colour is produced when ferric-ammonium sulphate is added to dilute solution

           of black-catechu .

                 By the addition of NaOH , the green colour turns to purple .

( IV ) Catachine when treated with Hcl , it produces Phloroglucinal , which turns along-with

           Lignine to give purple colour .

                For this purpose , Tannin extract is taken on Match-stick and dipped in conc.Hcl and heated

          near the flame

Therapeutic uses :

i)                    It is used as an Astringent , externally for boils , skin eruptions and ulcers .

ii)                   It is also used in Cough and Darrhoea .

iii)                 It has cooling and digestive properties .

iv)                 It is not much used medicinally .but for other purposes like dyeing and colouring , water softening , protective agent for fishing-nets and in manufacture of ion exchange resin .