To study the chemical constituents of Sappan Lignum. Chemical constituents were isolated by method of solvent extraction, repeated chromatography with silica gel, Sephadex LH-20, and ODS. The structures were elucidated based on spectro- scopic data. Fourteen compounds were isolated and their structures were identified as brazilin （1）, sappanone B （2）, （E）-3-（3,4- dihydroxybenzylidene）-7-hydroxychroman-4-one （3）, 3-deoxysappanone B （4）, brazilide A （5）, euxanthone （6）, quercetin （7）, rhamnetin （8）, sappanchalcone （9）, 3-deoxysappanchalcone （10）, butein （11）, 2,4,5-trihydroxybenzaldehyde （12）, 3,8,9-trihydroxy- 6H-benzo[c]chromen-6-one （13） and 13-sitosterol （14）. Compounds 12 and 13 were two new natural compounds, and the ^13C NMR data of compound 13 were reported for the first time. Compound 6 was the first xanthone isolated from the genus Caesalpinia.
To investigate the chemical constituents of the roots ofPolygala sibirica L. The separation and purification were performed by solvent extraction and repeated chromatography with silica gel, Sephadex LH-20, ODS columns, and semiprep. HPLC. The structures were elucidated by spectral analysis. Twelve known compounds were isolated and identified as tenuifoliside A （1）, tenuifoliside B （2）, glomeratose A （3）, 3＇,6-disinapoyl sucrose （4）, sibiricose A5 （5）, sibiricose A6 （6）, sibiricose A1 （7）, sibiricose A2 （8）, polygalatenoside E （9）, 1-O-L-arabinopyranosyl-O-（6→1）-β-D-glucopyranosyl-salicylate （10）, canthoside A （11）, and methyl- 3,4,5-trimethoxycinnamate （12）. Compound 11 was obtained from genus Polygala for the first time, and compounds 2, 9, 10 and 12 were isolated from this plant for the first time.
