[Splitted fractions and unoverlapping analysis of chemical constituents of Poria cocos].

With the combined applications of steam distillation, water extraction and alcohol precipitation, liquid-liquid extraction and column chromatography over macroporous resin, a splitted-fractions method of the chemical constituents of Poria cocos was established. The unoverlapping property of the fractions of P. cocos was qualitatively analysed by using principal component analysis and cluster analysis. With angle cosine, squared euclidean distance and the overlapping analysis of peak area of crude herbs, the unoverlapping property of the fractions of P. cocos was half-quantitatively analysed. The chemical components of P. cocos was divided into the fractions of polysaccharide, petroleum ether, ethyl acetate, alcohol eluate from macroporous resin and water eluate from macroporous resin. Non similarity degree among each chemical fraction was above 80% and main chemical components were identified. The established method for splitting fractions of P. cocos has good stability and repeatability and all chemical components in P. cocos could be completely divided into six fractions. It is the first time that the author half-quantitatively analyse the unoverlapping property of the chemical fractions of P. cocos.