Isolation and identification of chemical constituents from Rheum palmatum L.

Objective To isolate and identify the chemical constituents from Rheum palmatum L. Methods The chemical constituents of R. palmatum L. w ere isolated and purified by multiple chromatographic techniques( such as silica gel chromatography,Sephadex LH-20 and HPLC etc.). These compounds w ere identified by analysis of the spectral data and chemical properties. Results Six compounds w ere isolated from the ethyl acetate extract part of the R. palmatum L. ethanol extract and their structures w ere identified as methyl2-acetyl-3,5-dihydroxyphenylacetate (1),eriodictyol (2),dihydrokaempferol (3),2-methyl-5-carboxymethyl-7-hydroxychromone (4),2-methyl-5-methylcarboxymethyl-7-hydroxychromanone (5),2-methyl-5-methylcarboxymethyl-7-hydroxychromone (6). Conclusions Compounds 1-3 are isolated from Rheum genus for the first time. Compound 5 is a new natural product. Compound 6 is a new compound.