1- Free anthraquinone: rhein, chrysophanol, emodin, aloe-emodin
2- Anthraquinone glycoside.
3- Astringent compounds: catechin, epicatechin, free gallic acid, glucogallin.
In small dose: bitter stomachic and intestinal astringent.
In large dose: purgative followed by astringent effect.
Borntrager's test: rose-red colour.
Microsublimation: yellow needle crystals which gives red colour with KOH.
Test for purity:
When the powder is examined in ultra-violet radiation, no shining violet spots are seen ( to assure the absence of Rhapontic Rhubarb).