The Dynamic Accumulation Of Primary Active Components Of Apocynum Venetum L. Growing In Songnen Plain And Its Antioxidant Activity

Apocynum venetum L. wildly growing in Songnen grassland was regarded as research object in this thesis. Flavonoids are the important bioactive components and quercetin is the most important fraction in the flavonoids in A.venetum. The quantitative distributions of the total flavonoid and quercetin in different organs and the dynamic distributions of the total flavonoid and quercetin in stem and leaf of A. venetum in whole growing stage were measured, and the DPPH·and·OH scavenging capacities of the each sample and the dynamic variation of scavenging capacities of stem and leaf in whole growing stage were evaluated.Quantitative distribution of total flavonoid in the different organs of A. venetum from two sample locations (LY and ZMC) was of this order: flower> leaf> stem> root> fruit. From the re-greening stage to vegetative period, total flavonoid in stem accumulated rapidly and its content reached 1.950mg/g in pre-blooming stage and the highest peak, 2.390mg/g, in whole growing stage in post-blooming stage. Total flavonoid fell to 1.932mg/g in fructescence, and then re-rose another peak 2.241mg/g in leaf falling period. From the re-greening stage to vegetative period, the total flavonoids in leaf accumulated also rapidly and the content of total flavonoid reached 9.845mg/g in pre-blooming stage. Then it declined to a low level in flowering stage which the content of total flavonoid was 6.747mg/g. During post-blooming stage and fructescence, it raised rapidly again and reached the highest peak, 10.775mg/g, in whole growing stage. In leaf falling period, just 1.872mg/g flavonoid was detected in leaf.Quantitative distribution of quercetin in the different organs of A. venetum varied considerably too. The quercetin content was following the order: flower > leaf >stem > root > fruit. From the re-greening stage to vegetative period, quercetin in stem accumulated rapidly and the content reached 0.979mg/g in vegetative period. In post-blooming stage the content of total flavonoid was 1.687mg/g which is the highest peak in whole growing stage. Content of quercetin fell to 1.026mg/g in fructescence, and then re- rose to another peak, 1.215mg/g, in leaf falling period. The results indicated that quercetin was transferred to the organs that living through the winter after finishing distributing to leaf. From the re-greening stage to vegetative period, quercetin in leaf accumulated rapidly and its content reached 4.560mg/g in pre-blooming stage. Then it declined to 3.715mg/g in full flowering stage. From post-blooming stage the content of quercetin increased again and reached the highest peak, 5.630mg/g, in whole growing stage in fructescence. In leaf falling period, just 1.013mg/g quercetin was detected in leaf. Double peaks of quercetin dynamic accumulation suggested that during full flowering stage, quercetin was transferred from leaves and stems to flowers. The highest DPPH·scavenging activity was observed in flower, and the lowest activity was found in root. High DPPH·scavenging activity of the extract of stem of A venetum was observed in vegetative period, post-blooming stage, and leaf falling period respectively. After increasing in re-greening stage and vegetative period, the DPPH·scavenging activity of the extract of leaf of A venetum kept on a high level until the fructescence and it declined rapidly in leaf falling period.The highest·OH scavenging activity was observed in leaf, and the lowest activity was found in root. High·OH scavenging activity of the extract of stem of A venetum was observed in vegetative period, full flowering stage, and post-blooming stage respectively. The·OH scavenging activity of the extract of leaf of A venetum reached two tops respectively in full flowering stage and fructescence.