Roots are oblong, occasionally branched, and several or 10 are clustered on short rhizomes. The length is 5 ~10 cm and the diameter is1~ 4 mm. The surface is dark brown and red with longitudinal wrinkles. Brittle, easy to break, with light red xylem exposed on the section. Slight gas, bitter and slightly sweet. Cross section of root (diameter 3mm). The cork layer is cork cells with 10 sequence, containing brownish-red pigment, and there are traces of deciduous layer outside. The cell shape of parenchyma in cortex is larger; Phloem is annular around xylem; The cambium is not obvious, and the xylem is small, accounting for about 1/5 of the root diameter. It is composed of vessels, wood fibers and wood parenchyma cells, all of which are lignified. The rays of xylem and phloem are not obvious; Some parenchyma cells contain needle crystal bundles of calcium oxalate.

Physical and chemical identification 1. Take 0. 1g of this product powder, add 5ml of methanol for cold soaking for one hour, filter, evaporate the filtrate in a 20ml test tube in a water bath, add 2ml of water and 0.2ml of hydrochloric acid for hydrolysis for half an hour, and then cool. Shake with ether 10ml for 3min, take 5ml of ether solution and add 2N sodium hydroxide solution to shake, and the lower water solution should be purple (check alizarin anthraquinone). 2. Preparation of TLC sample: Take 0. 1g of this product powder, add 5ml of methanol solution for cold soaking 1 hour, filter, slightly concentrate and spot sample (for identification of free anthraquinone). Take a sample of ether solution in the physical and chemical identification item 1 (for identification of total anthraquinone). Adsorbent: silica gel g board. Developing agent: xylene-ethyl formate-hexane-formic acid-methanol (20:10: 8:1:0.5), add 0.5ml of distilled water and shake, and separate the upper solution. Spread 12cm. Alizarin and hydroxyl alizarin are purplish red in sunlight, and the purple color deepens in ammonia vapor. Observe the spot color under fluorescent lamp (365nm). Thin-layer chromatography takes 0. 1g of this product powder, adds 0.5ml of methanol, cold soaks it 1h, filters it, and slightly concentrates it as test solution. Alizarin and hydroxyl alizarin are used as reference substances, and are respectively spotted on the same glue G sheet, and xylene-ethyl formate-hexane-formic acid-methanol (20:/kloc) Check under sunlight or ultraviolet lamp (365nm). Spots or fluorescent spots with the same color in the chromatogram of the test sample corresponding to the chromatogram of the control sample.

Chemical constituents include anthraquinone glycosides: 2- methyl-1, 3,6-trihydroxy -9, 10- anthraquinone -3-O-(6'-O- acetyl) -α-L- rhamnosyl (1→ 2)-. 10- anthraquinone -3-α-L- rhamnosyl) (1→2)-β-D- glucoside, 2- methyl-1, 6- dihydroxy anthraquinone -3-O-(6'-O- acetyl)-. Also contains Qian can; Three arboxane triterpenoids: rubigin A and G, rubigin A.. In addition, it contains a new component with cancer activity, named Cyclohexoside RY- 1 and its aglycone RA-V.