Antioxidant Activity Of Bamboo Leaf Extracts From Seven Vaireties And Extraction Process Optimization

Because plant extracts with safe, efficient, stable, controllable, non-toxic and otheradvantages, the comprehensive utilization of plant resources has been a focus of people'sresearch and development. Flavonoids is the main function of the active ingredient of bambooleaf extracts, with excellent biological effect, so the application prospects are very wide.The paper is in order to fully describe the extraction technology and antioxidant activity ofbamboo leaf extracts, also discussed the bamboo leaf extracts ingredients and the relationshipbetween its antioxidant activity.The main results were as following:1. This study used Phyllostachys heterocycla, Pleioblastus amaru, Bambusa tuldoides,Bambusa chungii, Bambusa textilis, Chimonocalamus Hsueh and Indocalamus tessellates asthe research objects. Bamboo-leaf-flavonoids were extract by the heat reflux method andpurified by AB-8macroporous absorption resin. The yields from different varieties of bambooleaf extracts is1.70%～3.70%, the yields from Pl. amarus leaf extracts is the highest, the yieldsfrom I. tessellatus leaf extracts is the lowset. The Orientin and isoorientin from Ch. Hsueh leafextracts is the highest levels by2.52%~2.53%, Pl. amarus leaf extracts contains no Orientinand isoorientin; the vitexin from Pl. amarus leaf extracts is the highest levels by0.88%~0.89%, the vitexin from B. chungii leaf extracts is the lowest, about0.12%; the isovitexin fromB. tuldoides leaf extracts is the highest levels by2.22%～2.23%, the isovitexin from Pl.amarus leaf extracts is the lowest, about0.43%.2. The extractions were separated and structurally identified by HPLC. Then the bambooleaf extract were assayed based on DPPH radical scavenging capacity, hydroxyl radicalscavenging capacity, superoxide anion free radical scavenging capacity, and reduing powerwith TBHQ as the positive controls. The results showed that: the yield in Pl. amarus was themaximum, hit3.60%～3.70%; the amount of orientin and isoorientin in Ch. Hsueh was themaximum, hit2.5230%～2.5326%, the amount of vitexin in Pl. amarus was the maximum, hit 0.8870%～0.8896%, the amount of isovitexin in B. textilis was the maximum, hit2.2231%～2.2261%; Ch. Hsueh revealed the strongest scavenging capacity against DPPH,the IC50valuewas30.50mg/L, I. tessellates revealed the strongest scavenging capacity against hydroxylradical and superoxide anion free radical, the IC50value were339.32mg/L and324.87mg/L.3. To the principle of cost,To investigate the optimum extraction conditions for theBamboo leaf flavonoid extract.Using the heat reflux extract flavonoids of bamboo leave,concentration of ethanol,extraction time,ratio of material to liquid and the times of extractionwere optimized by using the single factor test and orthogonal design test．Flavonoid monomercontent measured by HPLC was chosen as the assessment indicesto evaluate the optimalextracting conditions. Result: The optimum extracting conditions was selected as follow: theratio of raw material to40%alcohol was15:1, four times and2h each time. Conclusion: Thismethod not only can effectively extract the flavonoids of bamboo leave, but also substantialcost savings,which can be used in extraction flavonoids as the preferred technology inindustrial.