Effect of dynamic distribution of steroid saponins from Paris polyphylla var. chinensis on medical material quality / 中草药

ABSTRACT

Objective: To obtain the optimum cultivation period and best harvesting month of P. polyphylla var. chinensis by studying on change regularity of biomass accumulation rate and steroid saponins from P. polyphylla var. chinensis with the changes of its harvesting time and medicinal parts. Methods: A high performance liquid chromatography-evaporative light-scattering detector (HPLC-ELSD) method was established to characterize content of six steroid saponins (Paris saponins I, II, VI, VII, V, and H) from P. polyphylla var. chinensis and its dynamic change regularity was detected; Drying rate was measured by oven-dry method to indicate biomass accumulation rate. Results: Drying rate increased with the planting ages and reached the highest level in the eighth year. There was a waving trend between drying rate and harvesting time and drying rate reached crest in January and June; The main steroid saponins of P. polyphylla var. chinensis were Paris saponin VII and Paris saponin H. The content of total saponins varied by `V' shaped with the increases of planting-year and reached the highest in the second and eighth year, and it changed by waving shape with the change of harvesting month and reached the crest in March and November; There was a distinct difference of total saponins among different parts of P. polyphylla var. chinensis stems and leaves > rhizome-forepart > rhizome-middle-part ≈ rhizome-end-part. The distribution of paris saponins VII decreased obviously from stems to rhizome-end-part while paris saponins H increased gradually. Conclusion: There were remarkable correlations among steroid saponins accumulation amounts and planting ages, harvesting month, and medicinal parts. The optimum cultivation period is eight years and best harvesting month is in November; The quality of medicinal materials would decline if only rhizome-end-part to be used; Paris saponin VII maybe a relative factor for germination and growth of P. polyphylla var. chinensis; Stems of P. polyphylla var. chinensis can be an important resource to extract steroid saponins, which have a profound significance to broaden resources of medicinal plants and improve resources utilization efficiency.