Qiu Jiying, Chen Xiangyan, Netrusov A I, Zhou Qingxin, Guo Danyang, Liu Xiaoyong, He Hailun, Xin Xue, Wang Yifen, Chen Leilei
Institute of Agro-Food Science and Technology & Shandong Provincial Key Laboratory of Agro-Products Processing Technology, Shandong Academy of Agricultural Sciences, Jinan, China.
Biological Faculty, M.V. Lomonosov Moscow State University, 1/12 Lenin's Hills, Moscow, Russia.
PLoS One. 2017 Jan 17;12(1):e0170141. doi: 10.1371/journal.pone.0170141. eCollection 2017.
The Ginkgo biloba is one of ancient trees that exists from billions of years ago, its leaf and nut are used as herbs and foods in China, while so far its pollen does not have any application except pollination. In order to evaluate the antioxidant activity of Ginkgo biloba pollen, and rapidly screen its antioxidative components, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging ability, total flavonoid, total phenol, and proanthocyanidin of Ginkgo biloba pollen were determined and compared with those of Ginkgo biloba leaf and nut, and the off-line DPPH-HPLC-PAD and HPLC-ESI-MS2 were applied for screening and identifying the antioxidant flavonoids in Ginkgo biloba pollen. The results showed that the DPPH scavenging ability of Ginkgo biloba pollen was much higher than Ginkgo biloba nut, but lower than Ginkgo biloba leaf, while the total content of flavonoid in Ginkgo biloba pollen was approximately 4.37 times higher than in Ginkgo biloba leaf. Further studies found that the major flavonol aglycone in Ginkgo biloba pollen was kaempferol, which accounted for 96.71% of the total aglycones (includes quercetin, kaempferol and isorhamnetin), and the main flavonoid components in Ginkgo biloba pollen were flavonoid glycosides. Finally, ten antioxidant peaks were screened and identified to be flavonoids (including kaempferol and nine flavonoid glycosides), so flavonoids were likely to be the main antioxidant components in GP, and among them, three novel kaempferol glycosides (peaks 1, 2, and 3) were found in Ginkgo biloba pollen for the first time, which had never been found in Ginkgo biloba.
银杏是一种从数十亿年前就已存在的古树，其叶和果实在中国被用作草药和食物，而到目前为止，其花粉除了用于授粉外没有任何其他应用。为了评估银杏花粉的抗氧化活性，并快速筛选其抗氧化成分，测定了银杏花粉的1,1-二苯基-2-苦基肼（DPPH）清除能力、总黄酮、总酚和原花青素，并与银杏叶和果实进行了比较，同时应用离线DPPH-HPLC-PAD和HPLC-ESI-MS2对银杏花粉中的抗氧化黄酮类化合物进行筛选和鉴定。结果表明，银杏花粉的DPPH清除能力远高于银杏果实，但低于银杏叶，而银杏花粉中黄酮类化合物的总含量约为银杏叶中的4.37倍。进一步研究发现，银杏花粉中的主要黄酮醇苷元是山奈酚，占总苷元（包括槲皮素、山奈酚和异鼠李素）的96.71%，银杏花粉中的主要黄酮类成分是黄酮苷。最后，筛选并鉴定出10个抗氧化峰为黄酮类化合物（包括山奈酚和9种黄酮苷），因此黄酮类化合物可能是银杏花粉中的主要抗氧化成分，其中，首次在银杏花粉中发现了3种新型山奈酚苷（峰1、峰2和峰3），在银杏中从未发现过。
