ABSTRACT
Objective::To establish a scientific and reasonable grade evaluation standard for Polygoni Multiflori Caulis. Method::The quality constant method was used to conduct a grade evaluation study on Polygoni Multiflori Caulis. A total of 16 batches of samples were collected from Chinese herbal slices enterprises and medicinal materials markets. By measuring its appearance traits (average quality and average thickness of the decoction pieces) and the intrinsic quality indicators (content of 2, 3, 5, 4′-tetrahydroxystilbene-2-O-β-D-glucoside), then its quality constant and percentage quality constant were calculated comprehensively, finally, the grades of Polygoni Multiflori Caulis were classified by quality constant method. Result::The quality constant of 16 batches of the decoction pieces was 0.054-0.417, and the percentage quality constant was 12.98-100.00.If these samples were divided into three grades, the quality constant shall be ≥0.334 for the first-grade decoction pieces, the quality constant shall be <0.334 and ≥0.209 for the second-grade decoction pieces, while for the third-grade decoction pieces, the quality constant shall be <0.209. Conclusion::The grade evaluation method based on quality constant can overcome the shortcomings of traditional evaluation method for decoction pieces, and can realize scientific, objective and simple classification of Polygoni Multiflori Caulis. This study enriches the research data of modern grade evaluation of Polygoni Multiflori Caulis, and provides reference for grade evaluation and market circulation of other decoction pieces.