Aim: Extraction and identification of diosgenin

Reference: 

1.Indian herbal pharmacopoeia. (2002). Revised new edition. Indian Drug

Manufacturers Association, Mumbai, 106-113.

2.Kokate, C. K. (1994). Practical pharmacognosy. Vallabh Prakashan, New Delhi.


Theory:

Diosgenin obtained from the tubers of plant Dioscoria deltoidea and D. composita and other

species of Dioscorea family Dioscoreaceae.

Glycosides are the naturally occurring complex organic substances which on hydrolysis gives

sugars and non-sugar parts sugar part is k/a glycon which is therapeutically inactive

and gives water solubility to it. While non-sugar part is known as aglycon are responsible

for therapeutic effect.

Saponins are the plant glycosides and are non-crystalline, dissolves in water and are toxic.

Diosgenin is  steroidal sapogenin (4-6%)  it  is  hydrolytic product of saponin doscin

saponine – high % of glycoside on hydrolysis to give aglycon portion k/a sapogenin

Saponin

a.    Steroidal (tetracylic triterpenoids)

b.   Pentacyclic triterpenoids


Structure: Disogenin


Diosgenin - 414.63

( C27H42O3 )

Disogenin is pentacyclic terpenoid saponine glycoside.

It is useful as precursor for synthesis of

sex hormone, cortisone, diuretic, steroids  and vit D.


Extraction Method 1:

Take the accurately weighed quantity of coarse powder of dioscorea tubers. Reflux the powder with 2N mineral acid for 4 hours.  Filter and dry the marc. Extract this dried marc with methanol for 6 hours. Filter and distill off solvent to 1/4th of its original volume. Keep this concentrate liquid in a refrigerator for 2 hours to form crystals of diosgenin.

 

Extraction Method 2:

Take the accurately weighed quantity of fresh dioscorea tubers and smash it in hammer mill. Keep this smashed material in a fermentor for 2 days. Dry this fermented material in air. Add sufficient quantity of mineral acid to bring about hydrolysis. Extract this solution with hepatane. Filter and concentrate slowly to obtain crystals of diosgenin.

 

Extraction Method 3:

Take the accurately weighed quantity of coarse powder of dioscorea tubers. Extract the powder with methanol for 6 hours. Filter and concentrate the filtrate to obtain a semisolid mass. Add dilute HCl and stir for 6 hours. Precipitates of diosgenin will be observed. Filter and purify the precipitate with alcohol.


Observation

·         Weight of plant taken (gm) (a):

·         Weight of diosgenin obtained (gm) (b):

·          % yield = (b*100)/a