Studies On Chemical Constituents And Quality Evaluation Of Traditional Chinese Medicine Poria Cocos (Schw.) Wolf

Fuling, the sclerotia of Poria cocos (Schw.) Wolf, is a well-known traditional Chinese medicine and recorded in the pharmacopoeia of P.R.China (2000 edition). It is used in many traditional Chinese prescriptions on account of its diuretic, sedative, tonic or anti-palpitative effects. Both the inner parts and the epidermis of the sclerotia of P. cocos were reported to contain several lanostane-type triterpene acids, which were generally considered to be the major medicinal components of the plant. A sysmatical research about Poria cocos was carried out for a better method to evaluate the quality of the crude drug. The main content and results were as follows: 1) The preparation of standard substance and identification of its structure Chemical constituents of Poria cocos were systematically investigated, two compounds were isolated from the alcohol extract by using solvent extraction, silica gel, pre-HPLC and recrystallization. By employing physical and chemical properties, modern spectrometric analysis techniques such as UV,IR,EI/MS,1H-NMR,13C-NMR,and DEPT, the structures of two compounds have been elucidated. They're 3β-acetoxy-16α-hydroxy-lanosta-8,24(31)-diene-21-oic acid(Pachymic acid), 3-oxo-16α-hydroxy-lanosta-7,9(11),24(31)-trien-21-oic acid (polyporenic acid C). In addition, 2D NMR experiments were used for the structure elucidation of pachymic acid. Pachymic acid has been chosen as the reference substance for qualitative and quantitative analysis of the crude drug for its speciality and content. 2) Research on the method of TLC As a control of pachymic acid, the thin layer chromatography condition was founded to analysis the crude character and quality for the first time. The mobile phase was chloroform-ethyl acetate-formic acid (10:1:0.2). 3) Determination of total triterpenes from Poria cocos by spectrophotometry Pachymic acid has been chosen as the reference substance for quantitative determination of total triterpenes in 10 samples. Total triterpenes was measured by spectrophotometry with 50 mg·mL^-1 vanillin-glacial acetic acid solution and perchloric acid as color-developing agent and detected at 540nm wavelegth. The liner range is 59.2¹77.6μg and gave a correlation (r) of 0.9992. The recovery was 97.31%, RSD 0.87%. The content of total triterpenes is no less than 0.45%. The spectrophotometry is suitable for the determination of total triterpenes. 4) Quantitative determination of pachymic acid by RP-HPLC The RP-HPLC method was used to determine the content of pachymic acid in Poria cocos. The analysis was carried out on Phenomenex Luna C18 column (4.6mm×150mm,5μm). The mobile phase is CH3CN-0.1%CH3COOH (75:25, V/V). The flow-rate was 1.0mL/min and wave-length at 210nm and temperature at 250C. The method was simple and had a good linear relationship. The liner range is 1.52⁷.60μg and gave a correlation (r) of 0.99942. The recovery was 96.9%, RSD 1.09%. The minimum content of pachymic acid should be 0.035%. The method is available, possible and accurate. 5) Studies on the fingerprint of P. cocos. We have made a preliminary experiment on the HPLC fingerprints, and find out ten common peaks in 10 samples. The method including five indexes (i.e. ratio of retention time, ratio of area, ratio of height, 3-point peak purity and similarity index) was employed to evaluate the similarity of mutual peaks of fingerprint of P. cocos. The result can be a base for the further qualitative or quantitative analytical research.