Method for the estimation of Withanolides content

Method for the estimation of Withanolides content

Reagent Required:

Methanol 50%v/v,  hexane L.R. Grade, Diethyl ether L.R. Grade, Distilled water, Sodium sulphate anhydrous L.R.Grade.

Glass wares and Apparatus Required:

Evaporating dish – 100mL, separating funnel –250mL.

            

Procedure:

Weigh accurately about 2.5gm sample (Extract) and transfer into a separating funnel. Add 15mL – 20mL of  50% v/v methanol (50 : 50 :: water : methanol) and shake well and filter, if necessary. Extract with hexane for four times, taking each extraction with 20mL of hexane. Discard hexane layer and extract hydroalcoholic layer with five 25mL portions of ether. Mix all the ether layer and wash two times with 25mL of water. Discard the water portion and take ether layer in a tared dish through anhydrous sodium sulphate. Evaporate the ether layer on water bath to dryness upto constant weight.

Calculate the percentage of total withanolides (w/w) as :

(A – B)  X 100

          W

Where:

A   = weight of residue + empty dish

B   = weight of empty dish

W  = weight of sample taken

For raw material : 10gm sample (20 #) is to be taken in the case of raw material and the quantity of  methanol(50%) shall be increased accordingly. Rest of the method is same as above.