岩白菜素
性状：本品为白色疏松的针状结晶或结晶性粉末；无臭，味苦；遇光或热渐变色。本品在甲醇中溶解，在水或乙醇中微溶。
功能：镇咳祛痰，用于慢性支气管炎。
岩 白 菜 素
                          yan bai cai su
                            bergeninum
[c14h16o9]=328.27
[characteristic] loose crystalline powder or acicula substance ,odourless,bitter in taste,the color will change gradually under the light/heat.solubillity:soluble in methanol,lightly soluble in water and alcohol.
melting range: dried on 130℃，test according to the china pharmacopiea(appendix vii c ),melting range should be 232~240℃.
specific optical rotation: dissolve 20mg in methanoland dilute to 1ml solution with the same solvent.test according to method provided in the china pharmacopiea(appendix vii e),calculated on the dried basis,the specific optical rotation should be -38°to -45°.
[identification]
(1) put 50mg into water(10ml),heat to make it dissolved,allow to cool.put 2 drops of potassium ferrocyanide ts(1 drops ferric trichloride dissolved in 1ml water ,fresh prepared) into 1ml the solution,yields emerald precipitate,then turns to blue.
(2) dissolve 5mg in 1ml methanol,put drops of methanol solution of  7% hydroxyamine hcl into the solution,then add the methanol of 10% potassium hydroxide,heat to freshly boiling,allow to cool.then,add the diluted of make the solution present acidic.add 1~2 drops of the alcohol solution of 1% ferric trichloride,yields amaranth.
(3) get the solution prepared accordance with the procedures under the below item [assay],examine according to procedures of spectrophotometry,the solution shows 2 absorption maxima,at 275nm and 220nm.
[examine]
loss on drying:maximum 6 per cent,by drying in an oven at 130℃ to constant weight.
total ash:not more than 0.1%(china pharmacopiea ixj).
[assay]  transfer an accurately weighed quantity of 20mg bergeninum to a to a 50-ml volumetricflask,add methanol  to dissolve,dilute with solvent to volume,and mix,transfer 5ml accuated weight of this solution to a 25ml volumetic flask,add methanol to dissolve,dilute withthe solvent to volume,mix.according the procedure of spectrophotometry,check the absorption rate at 275nm,calculated with the constant of absorption of bergeninum(e1cm1%)248.
  the contents of bergeninum(c14h16o9),on the dried basis,should be 97%to 103%.
[functions and indications] relieving cough and removing the phlegm.for chronic bronchitis use.
[usage and dosage]  taken orally,perdosage 0.125g,3 dosage /day.