Study On Efficient Extraction Used BBD And Seasonal Variation Of Flavonoids From Crataegus Pinnatifida In Northeast

In this study, Crataegus pinnatifida Bge. Var. Major N. E. Br. (C. Pinnatifida)as raw materials, TFC were determined by using aluminum chloride colorimetric method. Box-Behnken design (BBD) combined with response surface methodology (RSM) was used to optimize ultrasound-assisted extraction (UAE) of total flavonoids contents (TFC) from Crataegus pinnatifida and determine the optimum process parameters. Additionally, the variation of TFC of C. Pinnatifida extracts in different parts were investigated. The best harvest part was determined. In order to explore the influence of seasonal variations on C. Pinnatifida leaves, the variation of TFC in C. pinnatifida leaves were investigated. The best harvest time was determined.1.The variation of TFC in C. pinnatifida roots, twigs, leaves and fruits in September were investigated. The highest TFC in C. pinnatifida roots, tiwgs, leaves, fruits was 29.75 mg/g,29.70 mg/g,31.52 mg/g and 24.81 mg/g in September, respectively. All in all, C. pinnatifida leaves showed remarkable advantages in terms of higher TFC compared to C. pinnatifida roots, twigs and fruits.2.BBD combined with RSM was used to optimize UAE method, and the factors which effect the TFC in C. Pinnatifida leaves were investigated. The optimized extraction parameters were as follows: ratio of liquid/solid 15, temperature 40 ℃, ethanol concentration 40%, time 32 min, extract times 3, ultrasound power 300 W. Under these conditions, the TFC was 15.50 mg/g.Overall, the present results indicated that UAE was a suitable method for the extraction of total flavonoids from C. pinnatifida leaves. Compared with conventional maceration extraction (ME) and heat-refluxing extraction (HE) methods, UAE method showed remarkable advantages in terms of higher TFC.3.The influence of seasonal variations on TFC in C. pinnatifida leaves from May to October 2013 was investigated. The TFC of the C. pinnatifida leaf extracts were highest in September, the value was 31.52 mg/g. The variation of average of temperature, precipitation and daytime in 2013 were similar to these in 2004-2013, were higher in July and August. As intensity of photosynthesis enhanced in growth period, primary metabolism and secondary metabolism of C. Pinnatifida become active gradually, TFC increase continuously and reach the highest point in September.The results revealed that C. pinnatifida leaves in September possessed remarkable TFC, September was the best harvest time and C. pinnatifida leaves could be a valuable antioxidant natural source in the Northeast China.