Comparison of Cultivated and Wild-simulated Astragali Radix Based on Traditional Quality Evaluation / 中国实验方剂学杂志

ABSTRACT

ObjectiveBased on the traditional quality evaluation methods summarized in previous dynasties， this paper systematically contrasted cultivated Astragali Radix（CA） and wild-simulated Astragali Radix（WA） from the aspects of character， microstructure and chemical composition by modern technological means. MethodThe collected CA and WA were compared in characters and microscopic characteristics in cross section， and comparative analysis were performed on the contents of cellulose， extracts， carbohydrate， total flavonoids， total saponins， etc. Then ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometer（UPLC-Q-TOF-MS） and desorption electrospray ionization mass spectrometry imaging（DESI-MSI） were used to comparatively analyze the secondary metabolites and their spatial distributions in the xylem and phloem of CA and WA. ResultIn terms of characters， the characters and sectional features of WA was consistent with the characteristics of high-quality Astragali Radix， while the CA was quite different from the traditional high-quality Astragali Radix. In terms of microscopy， the phellem layer of CA was thin， and the section fissures were mostly distributed through the cambium in a long strip shape without obvious growth ring characteristics. The cork layer of WA was thick， and the cracks in the section were distributed in the center of the xylem and the outer edge of the phloem in an irregular cavity shape. The cambium was tight without cracks， and had obvious characteristics of a growth ring. In terms of chemical composition， the contents of water-soluble extract， 80% ethanol extract and sucrose of CA was significantly higher than those of WA， while the contents of total saponins， lignin and hemicellulose were significantly lower than those of WA. And the contents of 100% ethanol extract， total polysaccharides and total flavonoids in both of them were generally similar， but slightly higher in WA. The contents of 2 kinds of monoacyl-substituted flavonoid glycosides in the xylem of WA was significantly higher than those of CA， while the contents of 2 kinds of flavonoid aglycones and one flavonoid glycoside were on the contrary. The contents of 7 saponins in phloem of WA were significantly higher than those of CA. ConclusionThere are significant differences between CA and WA in characters， microstructure and chemical components， in which CA has a fast growth rate and a short planting period， and the primary metabolites such as water-soluble extracts and sucrose are more enriched， which is the reason for its firm texture and sweetness being significantly higher than those of WA. However， the contents of lignin， hemicellulose and some secondary metabolites in WA are significantly higher than those in the CA， which are close to the traditional description of characters and quality. Based on the results of this study， it is suggested to strengthen the production of WA， improve the supply capacity of WA， and gradually upgrade the current standard. It is recommended to increase the contents of monoacyl-substituted flavonoid glycosides， total saponins and other indicators that can characterize different production methods， so as to guide the high-quality production of Astragali Radix.