Effects of different field processing methods on volatile components of Chuanxiong Rhizoma: an exploration based on headspace gas chromatography-mass spectrometry / 中国中药杂志

The volatile oil of Chuanxiong Rhizoma(CX) is known as an effective fraction. In order to seek a suitable method for processing CX and its decoction pieces, this study selected 16 volatile components as indices to investigate how different processing methods such as washing/without washing, sun-drying, baking, oven-drying and far-infrared drying at different temperatures affected the quality of CX and its decoction pieces(fresh CX was partially dried, cut into pieces, and then dried) by headspace gas chromatography-mass spectrometry(GC-MS), cluster analysis, principal component analysis and comprehensive weighted scoring. The results showed that the rapid washing before processing did not deteriorate the volatile components of CX. Considering the practical condition of production area, oven-drying was believed to be more suitable than sun-drying, baking, and far-infrared drying. The CX decoction pieces with a thickness of 0.3-0.4 cm were recommended to be oven-dried at 50 ℃. The integrated processing(partial drying, cutting into pieces, and drying) did not cause a significant loss of volatile components. For the fresh CX, the oven-drying at 60 ℃ is preferred. The temperature should not exceed 60 ℃, and drying below 60 ℃ will prolong the processing time, which will produce an unfavorable effect on volatile components. This study has provided the scientific evidence for field processing of CX, which is conducive to realizing the normalization and standardization of CX processing in the production area and stabilizing the quality of CX and its decoction pieces.

Comparative study on free and bound phenolic acids before and after drying of Salvia miltiorrhiza / 中国中药杂志

There were significant differences in phenolic acid content between fresh and dried Salvia miltiorrhiza before and after drying. That is to say, the content of phenolic acid in S. miltiorrhiza significantly increased with the increase of dehydration during the drying process.In order to investigate the differences and transformation of free and bound phenolic acids before and after the drying process of S.miltiorrhiza, we studied hydrolysis method, hydrolysates and hydrolysis regularity of phenolic acids in S.miltiorrhiza. UPLC method was used to determine four main hydrolysates of bound phenolic acids, namely danshensu, caffeic acid dimer(SMND-309), caffeic acid, przewalskinic acid A(prolithosperic acid), and three main free phenolic acids in S.miltiorrhiza, namely rosmarinic acid, lithospermic acid, salvianolic acid B. The results of the acid-base hydrolysis experiment of salvianolic acid showed that the alkaline hydrolysis effect was significantly better than acid hydrolysis. The optimal alkaline hydrolysis condition was hydrolysis at 70 ℃ for 4 h with 2 mol·L~(-1) NaOH solution containing 1% ascorbic acid(Vit C). The hydrolysates of free phenolic acids were the same with the hydrolysates of bound phenolic acids. Fresh S.miltiorrhiza contains a low level of free phenolic acids and a high level of bound phenolic acids, which were exactly opposite to dried S.miltiorrhiza. It was suggested that a large amount of bound phenolic acids was accumulated during the growth of S.miltiorrhiza. These bound phenolic acids were coupled with polysaccharides on the cytoderm through ester bonds to form insoluble phenolic acids, which was not easy to be detected by conventional methods. However, during drying and dehydration processes, the bound phenolic acids were converted to a large amount of free phenolic acids under the action of the relevant enzyme.

Study on dynamic changes of chemical constituents during different drying processes of Salvia miltiorrhiza / 中国中药杂志

There is no consensus on the drying methods of Salvia miltiorrhiza in ancient and modern times,especially on the content of phenolic acid in fresh S. miltiorrhiza. In order to further explore the content of main components in fresh S. miltiorrhiza and study the dynamic changes during the drying process,the content of main components was used as the index in this study to evaluate the processing method,drying method,correlation between dehydration rate and component content for fresh S. miltiorrhiza. In addition,the sealed and unsealed parallel control groups were set to carry out verification test during the drying process. UPLC method was used for determination of seven main components including rosmarinic acid,lithosperic acid,salvianolic acid B,cryptotanshinone,tanshinoneⅠ,methylene salianolate and tanshinone ⅡAin S. miltiorrhiza. The results showed that the fresh S. miltiorrhiza contained low levels of phenolic acid,and the content of phenolic acid increased significantly with the increase of dehydration rate during drying process,while the change of tanshinone was not obvious. In the comparison of three drying methods,we found that drying at 50 ℃ was better than drying in the sun,and drying in the sun was superior to drying in the shade. So,drying at 50 ℃ was the best drying method. The correlation between dehydration and phenolic acid content of S. miltiorrhiza was analyzed by verification test and SPSS software,which further proved that the dehydration rate was significantly positively correlated with the content of phenolic acid components. This study provides reference for the production processing and drying methods of S. miltiorrhiza medicinal materials,which is of great significance for improving the quality of S. miltiorrhiza.