Comparative analysis of chemical profiles of Radix Astragali between ultrafine granular powder and sliced traditional material

Abstract

Radix Astragali, one of the most popular herbs in traditional Chinese medicine (TCM), is used to strengthen the immune system, protect liver function, fight bacteria and viruses, and treat diabetes, heart failure and seasonal allergies. In recent years, a new form of Radix Astragali material processed by cell wall disrupting technology, namely ultrafine granular powder (UGP) has been introduced into the market. In order to determine chemical consistency and homogeneity of the UGP material prepared from sliced traditional materials (TM) of Radix Astragali, multiple batches of the UGP and TM samples derived from Astragalus membranaceus var. mongholicus were analyzed by UHPLC/DAD-MS using isoflavones and triterpenoid glycosides as marker compounds. The results demonstrated that the chemical profiles of UGP was identical or similar to that of TM, but UGP was highly homogeneous in terms of marker compound contents as assessed, e.g., by the relative standard deviation values of the nine marker compounds in the range of 8.55%−43.80% for TM2 compared against 1.70%−8.38% for UGP2. Macromolecular component preparation and 1H NMR analyses indicated that TM4 and its corresponding UGP4 produced similar polysaccharides, but the later had approximately two-fold dissolution rate of the polysaccharides when compared to the former (yield 7.22 ± 0.35% vs 3.39 ± 0.20%). This study confirms that UGP of Radix Astragali is chemically consistent and homogenous, supporting its use as a promising material in TCM prescriptions.

Keywords

• radix astragali
• ultrafine granular powder
• isoflavones
• triterpenoid glycosides
• polysaccharides