Quality Analysis of Different Specification Grades of Astragalus Membranaceus Var. Mongholicus (huangqi) from Hunyuan, Shanxi

Background: Huangqi is a famous Chinese medicinal material whose Dao-di producing area is Hunyuan, Shanxi. Huangqi produced in Hunyuan, Shanxi, were divided into several different specifications and grades according to the diameters and different positions of root system. Objective: This article investigates the quantitative characteristics of chemical compositions in different specifications and grades of Astragalus membranaceus var. mongholicus roots, aiming to elucidate the correlation between specifications and/or grades and chemical compositions in Huangqi. Methods: Based on the field investigation, samples of Huangqi collected from Hunyuan, Shanxi, were divided into different specifications and grades. The content of seven flavonoids and five saponins in Astragalus membranaceus var. mongholicus roots of different specifications and grades were determined simultaneously by HPLC-diode-array detection-evaporative light-scattering detection (HPLC-DAD-ELSD). Results: Huangqi was processed by traditional methods, and its commercial specification was classified by different parts of the root system, such as ge-da-tou, hong-lan-qi, zheng-bai-qi, fu-bai-qi, mao-wei-zi, and qi-jian. The total content of seven flavonoids and five saponins in ge-da-tou, qi-jian were lower. The total content of seven flavonoids in hong-lan-qi was much higher, while that of five saponins was much lower. The total content of seven flavonoids in lateral roots or fibrous roots were higher, and that of five saponins was lower, such as zheng-bai-qi, fu-bai-qi, and mao-wei-zi. According to the root diameters, Huangqi was classified to special grade, grade I, grade II, grade III, grade IV, or grade V. Among six grades of Huangqi, the total content of seven flavonoids in grade III, grade IV, and grade V were lower, while the total content of five saponins in them were much higher. Conclusions: There is an obvious difference on the distribution pattern of contents of seven flavonoids and five saponins in Huangqi of different specifications and grades, which provide a certain scientific basis for the quality evaluation of Huangqi. Highlights: The content of seven flavonoids and five saponins in Huangqi were determined by HPLC-DAD-ELSD. The relationship between the commercial specification grades and chemical components of Dao-di herbs Astragalus membranaceus var. mongholicus (Huangqi ) from Hunyuan, Shanxi were revealed, which provided a chemical basis for the classification of commercial specification grades of dao-herbs Astragalus membranaceus var. mongholicus (Huangqi ) from Hunyuan, Shanxi.