Plant source:The dry root of Astragalus membranaceus (Fisch. )Bge.(Main origin of Gansu) or Astragalus membranaceus (Fisch. ) Bge. var. mongholicus ( Bge. ) Hsiao(Main origin of Inner Mongolia) Appearance: White powder Molecular Formula: C30H50O5 Molecular Weight: 490.72 CAS No.:78574-94-4,84605-18-5 Assay Test method: HPLC-RID or HPLC-ELSD