title: Seasonal variations of the antioxidant composition in ground bamboo Sasa argenteastriatus leaves.
abstract: Sasa argenteastriatus, with abundant active compounds and high antioxidant activity in leaves, is a new leafy bamboo grove suitable for exploitation. To utilize it more effectively and scientifically, we investigate the seasonal variations of antioxidant composition in its leaves and antioxidant activity. The leaves of Sasa argenteastriatus were collected on the 5th day of each month in three same-sized sample plots from May 2009 to May 2011. The total flavonoids (TF): phenolics (TP) and triterpenoid (TT) of bamboo leaves were extracted and the contents analyzed by UV-spectrophotometer. Our data showed that all exhibited variations with the changing seasons, with the highest levels appearing in November to March. Antioxidant activity was measured using DPPH and FRAP methods. The highest antioxidant activity appeared in December with the lowest in May. Correlation analyses demonstrated that TP and TF exhibited high correlation with bamboo antioxidant activity. Eight bamboo characteristic compounds (orientin, isoorientin, vitexin, homovitexin and p-coumaric acid, chlorogenic acid, caffeic acid, ferulic acid) were determined by RP-HPLC synchronously. We found that chlorogenic acid, isoorientin and vitexin are the main compounds in Sasa argenteastriatus leaves and the content of isovitexin and chlorogenic acid showed a similar seasonal variation with the TF, TP and TT. Our results suggested that the optimum season for harvesting Sasa argenteastriatus leaves is between autumn and winter.
authors.affiliation: Agriculture and Food Science School, Zhejiang Agriculture and Forestry University, Lin'an 311300, China.|School of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310029, China.
authors.forename: Qinxue
authors.initials: Q
authors.lastname: Ni
authors.affiliation: Agriculture and Food Science School, Zhejiang Agriculture and Forestry University, Lin'an 311300, China.
authors.forename: Guangzhi
authors.initials: G
authors.lastname: Xu
authors.affiliation: Agriculture and Food Science School, Zhejiang Agriculture and Forestry University, Lin'an 311300, China.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Agriculture and Food Science School, Zhejiang Agriculture and Forestry University, Lin'an 311300, China.
authors.forename: Qianxin
authors.initials: Q
authors.lastname: Gao
authors.affiliation: Nurturing Station for the State Key Laboratory of Subtropical Silviculture, Zhejiang Agriculture and Forestry University, Lin'an 311300, China.
authors.forename: Shu
authors.initials: S
authors.lastname: Wang
authors.affiliation: Agriculture and Food Science School, Zhejiang Agriculture and Forestry University, Lin'an 311300, China.
authors.forename: Youzuo
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000975:Antioxidants / Q000032:analysis* / Q000378:metabolism; D047310:Apigenin / Q000032:analysis / Q000378:metabolism; D002109:Caffeic Acids / Q000032:analysis / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003373:Coumaric Acids / Q000032:analysis / Q000378:metabolism; D005419:Flavonoids / Q000032:analysis / Q000378:metabolism; D005960:Glucosides / Q000032:analysis / Q000378:metabolism; D010636:Phenols / Q000032:analysis / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry* / Q000378:metabolism; D011422:Propionates; D031787:Sasa / Q000737:chemistry* / Q000378:metabolism; D012621:Seasons; D014315:Triterpenes / Q000032:analysis / Q000378:metabolism
chemical_list: D000975:Antioxidants; D002109:Caffeic Acids; D003373:Coumaric Acids; D005419:Flavonoids; D005960:Glucosides; D010636:Phenols; D010936:Plant Extracts; D011422:Propionates; D014315:Triterpenes; D047310:Apigenin; C004999:ferulic acid; C065886:orientin; C495469:p-coumaric acid; C049772:isovitexin; C040048:caffeic acid