Effect of phytohormones induced and abiotic stresses on resveratrol content and optimization of resveratrol flash-extraction in polygonum cuspidatum roots

The effects of UV lights,salicylic acid,ethephon and H2O2 on resveratrol induction in fresh polygonum cuspidatum roots were studied. The effects of extraction temperature,extraction time,ethanol concentration and solid-liquid ratio on resveratrol content were investigated.Based on the single factor experiments,the optimization of resveratrol flash-extraction process was carried by the orthogonal test.And the resveratrol content was analyzed by HPLC. The results showed that the resveratrol content in polygonum cuspidatum could reach its maximum( improve 72%) after UV radiation 15 min and dark treatment 24 h.Its content increased by more than four times after soaking in the 10 mmol / L salicylic acid for 24 h and it increased by 34% after soaking in 5% H2O2 for 24 h.But ethephon did not work. The best flash-extraction conditions were as follows: extraction temperature 50 ℃,extraction time 60 s,ethanol concentration 80% and solid-liquid ratio 1 ∶ 30 g / m L.Under these conditions,the extraction rate of resveratrol was 0.1877%.