Studies On The Method Of Quality Control Of Paeony Root And Pharmacokenetic Of Total Glucoside Of Paeony

Paeony root is a commonly used traditional Chinese medicine. It is specified in Chinese Pharmacopoeia (2005 version) that red peony root is the dried root of Paeonia lactiflora Pall. and Paeonia veitchii Lynch. and that white peony root is the decorticated, boiled and dried roots of Paeonia lactiflora Pall.. In the present study, the chemical constituents in white peony root, methods of quality control of paeony, processing of white peony root and pharmacokinetics of total glucoside of paeony was discussed.Eleven compounds were separated from white peony root by using different isolating technique. On the basis of chemical properties and spectroscopic analysis, the compounds were identified as: paeoniflorin sulfonate, paeoniflorin, albiflorin, benzoylpaeoniflorin, catechin, gallic acid, 1,2,3,4,6-pentagalloyglucose, methyl gallate, ethyl gallate, sucrose andβ-sitosterol. Among them, paeoniflorin sulfonate was a novel compound, which was presumed a processing induced artefact from white peony root. Therefore, it was necessary to study the effect of processing on the quality of white peony root.Thirty seven samples of white peony roots and 34 samples of red peony roots were collected from drug stores or from their habitats around China and the quality control method was developed.The HPLC fingerprint used for the quality control of white peony roots was established after investigating chromatography and extracting condition and eight peaks were identified as gallic acid, paeoniflorin sulfonate, catechin, albiflorin, paeoniflorin, 1,2,3,4,6-pentagalloyglucose, benzoic acid and benzoylpaeoniflorin. Thirty seven samples of white peony roots were analyzed with the HPLC fingerprint, and the data were used for similarity evaluation. It was indicated that the 37 samples were identified into three types. The similarity of three types was 0.9-1.0, 0.6-0.9 and 0.2-0.4, respectively. The controlled white peony roots and samples from their habitats were in the same type and the similarity of samples in the same types was close with each other, which showed that the fingerprint could divided white peony roots. The method was a supplement to the quality control of white peony roots. At the same time, it was showed that the viaration of the ratios of paeoniflorin sulfonate, paeoniflorin and albiflorin had serious effect on the type of white peony roots.The fingerprint of red peony root was established in the same way and eight peaks were identified as gallic acid, catechin, albiflorin, paeoniflorin, 1, 2, 3, 4, 6-pentagalloyglucose, benzoic acid, benzoylpaeoniflorin and paeonol respectively. Thirty seven samples of white peony roots were analyzed with the HPLC fingerprint, and the data were used for similarity evaluation. It was indicated that the 37 samples could be classified into two types no matter Paeonia lactiflora Pall. or Paeonia veitchii Pall. was used as the reference chromatographic fingerprint. One type of Paeonia lactiflora Pall., the other Paeonia veitchii Pall., which was conformed with the result of morphology identification. It was showed that the fingerprint could identify white and red peony roots. The method was simple and rapid, which is a significant addition to the traditional identification. At the same time, it was showed that the great difference between Paeonia lactiflora Pall. and Paeonia veitchii Pall. lies in the contents of gallic acid, 1, 2, 3, 4, 6-pentagalloyglucose and tannin.The developed fingerprint method were also used distinguish white peony roots and red peony roots.A reversed phase HPLC method was established for simultaneous determination of eight major constituents, namely gallic acid, paeoniflorin sulfonate, catechin, paeoniflorin sulfonate, albiflorin, paeoniflorin, benzoic acid, pentagalloylglucose and benzoylpaeoniflorin in red peony root and white peony root, with paracetamol as internal standard. The method provided good reproducibility with precision of less than 4.34% and good accuracy with recovery of more than 93.16%.Thirty seven white peony roots and 34 red peony roots were determined with the developed quantitative method. Following results were achieved from the analysis. 1. There were significant difference in constituents between white peony roots and red peony roots. And the content difference in paeoniflorin, albiflorin, paeoniflorin sulfonate and benzoic acid was the most prominent. Paeoniflorin sulfonate only existed in white peony roots. The content of albiflorin in white peony root was much higher than that in red peony roots. While, the contents of paeoniflorin and benzoic acid in red peony roots were much higher than those in white peony roots. 2. Among 37 samples of white peony roots, there were only 20 samples whose contents of paeoniflorin was in accordance with the rule of Ch.P.., while paeoniflorin sulfonate was the predominating constituents in 16 samples. 3. The content of gallic acid in Paeonia veitchii Pall. was nearly ten times of that in Paeonia lactiflora Pall.. And, the content of 1, 2, 3, 4, 6-pentagalloyglucose was much higher than that in Paeonia lactiflora Pall.. 4. All red peony samples contained paeoniflorin above 2.5% except that one sample. Therefore, it could be concluded that the lowest limit ofpaeoniflorin in Paeonia lactiflora Pall. specified in ChP was worth to study. According to the above results, it was suggested that the quantitation of albiflorin should be added to the standard for control of white peony roots and the limit of paeoniflorin should be promoted in the standard for control of red peony roots.The samples with different years of growth, grads, habitats were compared with the established quantitative method. It was showed that the content of paeoniflorin increased with years of growth. On the contrary, the content of abiflorin decreased. The analysis results also could explain why the tail white peony roots was not used as medicine. But the rule of viaration of constituents between grade one and grade two was not found. And, the determined results of root from Hangzhou and Bozhou indicated that the allegation of root from Hangzhou is the best should be investigated.The effect on the constituents in white peony root of decorticating, boiling and fumigating by burning of sulphur was discussed. After boiling, the content of constituents decreased except for gallic acid and 1, 2, 3, 4, 6-pentagalloyglucose. It was also confirmed that paeoniflorin sulfonate was a processing induced artefact from white peony root, which would decrease the content of albiflorin. Preliminary pharmacological experiment showed that paeoniflorin sulfonate did not possess the effect of paeoniflorin on stomach intestine smooth muscle. Therefore, it was suggested that the limit of paeoniflorin sulfonate be added to the standard for control of white peony roots.The HPLC-MS-MS methods were developed to determine paeoniflorin, albiflorin and simultaneously determine these two compounds in rat plasma. The methods were sensitive, accurate and rapid. It settled out the problem that paeoniflorin and albiflorin could not be detected in normal dosage. It also provided a good example of applying modem analysis technique for determination of traditional medicine in vivo. The HPLC-MS-MS method was applied to a pharmacokinetie study of paeoniflorin and albiflorin after oral administration of paeoniflorin, albiflorin and total glucoside of paeony. The parameters were calculated according to concentration-time curve. After oral administration of paeoniflorin and total glucoside ofpaeony, the relevant parameters for paeoniflorin were C_max 836.4, 947.9 ng/ml, T_max 20, 19 min, t_1/2 122.4, 64.9 min, AUC_0-∞ 81011.4, 97758.2 ng.min/ml, respectively. The result of statistics analysis showed, there was no significant differences (p＞0.05) in C_max and T_max. On the contrary, there was in AUC_0-t Land t_1/2(p＜0.05). It was indicated that the pharamacokenetic characteristics of paeoniflorin were affected by other constituents in total glucoside of paeony. After oral administration of albiflorin in low, medium and high dosage, the relevant parameters for albiflorin were C_max 221, 434, 817 ng/ml, T_max 20, 22, 19min, t_1/2 64.5, 70.5, 6.6min, AUC_0-∞ 15948.8, 38948.7, 72717.8 ng.min/ml. The result of statistic analysis showed the pharmacokinetic of albiflorin was linear in the three dosages. After oral total glucoside of paeony, the relevant parameters for albiflorin was C_max 275.3 ng/ml, T_max 19 min, t_1/2 63 min, AUC_0-∞ 11592.0 ng.min/ml. By comparing the parameters after oral administration of albiflorin in low dosage with that after oral administration of total glucoside of paeony, there were no significant differences(p＞0.05) in C_max,T_max,t_1/2 and AUC_0-∞. It was idicated that pharamacokenetic characteristic of albiflorin was not effected by other constituents in total glucoside of paeony.It was also showed t_1/2 of both paeoniflorin and albiflorin were about 65 min, which indicated that the times per day of administration in clinical should be increased.The present research provided a significant exploration for the modernization of TCMs.