Cascara Sagrada— Usually in flattened or transversely curved pieces,occasionally in quills of variable length and from 1to 5mm in thickness.The outer surface is brown,purplish brown,or brownish red,longitudinally ridged,with or without grayish or whitish lichen patches,sometimes with numerous lenticels and occasionally with moss attached.The inner surface is longitudinally striate,light yellow,weak reddish brown,or moderate yellowish brown.The fracture is short with projections of phloem fiber bundles in the inner bark.

Histology— It shows a yellowish brown,purple,or reddish brown cork of up to 10or more rows of small cells;stone cells in yellowish,tangentially elongated groups of 20to 50cells in the cortex,pericycle,and outer phloem regions;phloem rays 1to 4cells wide,15to 25cells deep,frequently diagonal or curved,forming converging groups;phloem fibers in small bundles,more or less surrounded by crystal fibers and located between the phloem rays;parenchyma with brown walls and containing starch grains and calcium oxalate crystals.

Powdered Cascara Sagrada— Moderate yellowish brown to dusky yellowish orange.It shows numerous broken phloem fiber bundles with accompanying crystal fibers containing monoclinic prisms of calcium oxalate;stone cells more or less adherent,in small groups with thick,finely lamellated and porous walls;fragments of reddish brown to yellow cork;masses of parenchyma and phloem ray cells colored reddish brown to orange upon the addition of a solution of an alkali;starch grains spheroidal,up to 8µm in diameter;calcium oxalate in monoclinic prisms or rosette aggregates from 6to 20µm in diameter,occasionally up to 45µm in diameter.

A: Add 100mg of powdered Cascara Sagrada to 10mLof hot water,shake the mixture occasionally until it is cold,filter,dilute the filtrate with water to 10mL,and add 10mLof 6Nammonium hydroxide:an orange color is produced.

B: It becomes red to reddish brown in color when treated with 6Nammonium hydroxide.

C: Macerate 100mg of powdered Cascara Sagrada with 1mLof alcohol,add 10mLof water,boil the mixture,then cool,filter,and shake the filtrate with 10mLof ether:a greenish yellow ether solution separates.Shake 3mLof this ether solution with 3mLof 6Nammonium hydroxide,and dilute the separated ammonia solution with 20mLof water:a distinct orange-pink color remains.

Ferric chloride solution— Dissolve 100g of ferric chloride in water to make 100mL.

Assay solution— Add about 1g of Cascara Sagrada,accurately weighed,to about 70mLof boiling water,boil for several minutes,with stirring,allow to cool,and transfer with the aid of water to a 100-mLvolumetric flask.Dilute with water to volume,mix,and filter through suitable filter paper.

Assay preparation— Pipet 10mLof Assay solutioninto a separatory funnel containing 5mLof water and 2drops of 1Nhydrochloric acid.Extract with 40mLof carbon methylene chloride,and transfer the lower layer to a second separatory funnel.Add 10mLof water to the second separatory funnel,and shake.Allow to separate,discard the lower layer,and transfer the water layer to the first separatory funnel.Extract the combined water layers with 40mLof methylene chloride,and transfer the lower layer to the second separatory funnel.Add 10mLof water to the second separatory funnel,and shake.Allow to separate,discard the lower layer,and transfer the water layer to the first separatory funnel.Extract the combined aqueous phase with 30mLof clear,freshly prepared water-saturated ethyl acetate,and transfer the water layer to another separatory funnel.Repeat the extraction with two additional 30-mLportions of the freshly prepared water-saturated ethyl acetate.Add 5mLof water to the combined ethyl acetate extracts,shake,allow the phases to separate,discard the ethyl acetate extracts,and add 30mLof the freshly prepared water-saturated ethyl acetate to the water wash.Shake,allow the phases to separate,and discard the ethyl acetate phase.Transfer the combined aqueous phases,with the aid of water,to a 50-mLvolumetric flask.Dilute with water to volume,and mix.

Procedure— Pipet 15mLof Assay preparationinto a flask containing 2mLof Ferric chloride solutionand 12mLof hydrochloric acid.Attach a condenser arranged for refluxing,and heat for 3hours by keeping the flask immersed in boiling water or continuously exposed to steam heat.Cool,wash down the condenser,and transfer to a separatory funnel with the aid of 4mLof 1Nsodium hydroxide and five 6-mLportions of water.Extract with 20mLof methylene chloride,and transfer the lower layer to another separatory funnel.Repeat the extraction with three additional 20-mLportions of methylene chloride,wash the combined methylene chloride extracts with two 10-mLportions of water,shaking each time for 2minutes,and discard the water washings.Transfer the washed methylene chloride extract to a 100-mLvolumetric flask,dilute with methylene chloride to volume,and mix.Evaporate a 20.0-mLportion carefully on a water bath to dryness,and dissolve the residue in 10.0mLof a 1in 200solution of magnesium acetate in methanol.Determine the absorbance,against methanol as a reference,in 1-cm cells at the wavelength of maximum absorbance at about 515nm.Calculate the quantity,in mg,of cascarosides in the portion of Cascara Sagrada taken by the formula: in which AUis the absorbance of the solution from the Assay preparation.

Ferric chloride solution and Assay solution—Prepare as directed in the Assay for cascarosides.

Assay preparation— Pipet 10mLof Assay solutioninto a separatory funnel containing 5mLof water and 2drops of 1Nhydrochloric acid.Extract with 40mLof methylene chloride,and transfer the lower layer to a second separatory funnel.Add 10mLof water to the second separatory funnel,and shake.Allow to separate,discard the lower layer,and transfer the water layer to the first separatory funnel.Extract the combined water layers with 40mLof methylene chloride,and transfer the lower layer to the second separatory funnel.Add 10mLof water to the second separatory funnel,and shake.Allow to separate,and discard the lower layer.Transfer the combined water layers,with the aid of water,to a 50-mLvolumetric flask,dilute with water to volume,and mix.

Procedure— Proceed as directed for Procedurein the Assay for cascarosides,except to evaporate a 15.0-mLportion of the methylene chloride solution instead of 20.0mL.Calculate the quantity,in mg,of total hydroxyanthracene derivatives in the portion of Cascara Sagrada taken by the formula: in which AUis the absorbance of the solution from the Assay preparation.