Page 247 - Pharmacognosy 2 PG303
P. 247

Pharmacognosy-2 (PG303)             Level 2  Clinical Pharmacy-Pharm D

     5- Part of a single fiber.     12- Fragment of a bordered
     6- Fragment of a large vessel  pitted vessel.
     with elongated pits.           13- Part of a medullary ray in
                                    radial longitudinal section
     7- Part of a group of smaller  with underlying thin-
     vessels with bordered pits.    walled parenchyma and
                                    part of a bordered pitted
                                    vessel

Tests for Identity
   1- Test for sugars: Boil I gm of Liquorice, in powder or in thin shavings, with
       20cc of water for 10 minutes. Filter, mix 5cc of filtrate with 5cc of
       Fehling's solution and warm, a red precipitate of copper oxide produced.
   2- Mix a little powdered Liquorice with 1-2 drops of 66% sulfuric acid, an
       orange red color is produced.
   3- Shake the aqueous decoction of Liquorice, a voluminous froth is
       produced.

Tests for purity
       Powdered Liquorice contains no foreign starch granules (flour), no yellow

masses (curcuma), no sclereids (olive stones).

Constituents

       2-15% triterpenoid saponins, mainly glycyrrhizin (ammonium and calcium

salts of glycyrrhizinic acid) and 24-hydroxy-glycyrrhizin, which taste 50 and 100

times as sweet as sucrose, respectively. On hydrolysis, glycyrrhizinic acid affords

diglucuronic acid and the aglycone glycyrrhetinic acid. There are, in addition, many

other triterpenoid saponins, some of whose aglycones are known, e.g. glabranin-A
and B, glycyrrhetol, glabrolide, isoglabrolide... etc. Triterpenes, sterols are β-
amyrene, onocerin, β –sitosterol and stigmasterol.

       More than 30 flavonoids and iso-flavonoids; and coumarins as herniarin,
umbelliferone, etc.

Uses
       I- As an expectorant with secretolytic and secretomotor actions for cough

and bronchial catarrh, also for inflammation of the upper respiratory tract. The
active substances are saponins, especially glycyrrhizinic acid, which also has
bacteriostatic and antiviral activity. The saponins inhibit the growth of influenza A
viruses in hen embryo. The antiviral action is based on the induction and

                                    204
   242   243   244   245   246   247   248   249   250   251   252