【作者】 曾佑炜；

【导师】 彭永宏；

【作者基本信息】 华南师范大学 ， 植物学， 2004， 硕士

【摘要】 我国鲜花资源丰富，花卉的食用和药用在我国有悠久的历史。花卉中许多具有抗氧化作用与保健功效的活性成份可以补充人们的膳食，开发和利用天然抗氧化活性物质已成为人们关注的热点。 通过对45种鲜花DPPH^·、^·OH、O₂^（?）清除能力的比较，发现红玫瑰花对3种自由基的清除能力较强，不同花卉粗提液对DPPH^·的清除能力与多酚含量呈极显著正相关（r=0.880），表明多酚可能是鲜花中主要的抗氧化物质，1.00mg红玫瑰鲜花对DPPH^·的清除能力相当于18.74μgVc。 通过对玫瑰花抗氧化能力的研究表明：（1）玫瑰花不同品种之间花蕾和成花对3种自由基的清除能力与多酚含量都呈极显著正相关（p＜0.01），比较结果为红色品种的抗氧化能力普遍强于金黄色和白色品种；（2）不同发育时期的玫瑰花随开放程度的增加对3种自由基的清除能力、多酚和黄酮含量都呈下降趋势，即在花蕾期表现较高水平，但每朵鲜花的平均鲜重和平均多酚含量在第6期最高；（3）经短期贮藏后，瓶插玫瑰花的多酚、黄酮和Vc含量初期呈上升趋势，对3种自由基的清除能力也相应增强。4℃贮藏更有利于保持抗氧化物质的活性，但4d后开始下降；（4）不同溶剂的提取液中，热水提取液对DPPH^·的清除能力强于丙酮、水和乙酸乙酯等溶剂的超声波提取液；（5）随着提取温度升高，提取液的抗氧化能力逐渐增强，但100℃提取30min后抗氧化能力和多酚含量并无显著变化（p＞0.05）；（6）在一定的范围内，粗提液的抗氧化能力与加入剂量呈线性变化（r=0.991：y=15.792x+14.745）；（7）提取液在pH=5时抗氧化能力最好，与其他pH条件达差异显著水平（P＜0.05），碱性条件会减弱或破坏提取液的抗氧化能力。 用气相色谱／质谱分析玫瑰花的乙醇提取物，检测出18种物质，其中带“-OH”羟基团物质总量达到75.014％，用四种不同基质分离玫瑰花热水提取液，发现采用CM-52阳离子交换纤维素柱，水-乙醇梯度洗脱，对粗提液的分离效果最好，并可起到浓缩作用。4℃保存CM-52分离的活性物质，结果120d后仍然保持很强的抗氧化能力。更多还原

【Abstract】 There are good resources of fresh flowers, and many of them are widely used as traditional medicines and food products in China. The components with antioxidant activities or specified health use are rich in flowers and can act as dietary supplement. It becomes a hot field to exploit and utilize natural antioxidant resource.The antioxidant effects in 45 kinds of fresh flowers obtained in this study were evaluated in three ways: using l,l-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, hydroxyl radical scavenging activity and superoxidant-dismutase (SOD)-like activity. The results were showed there was significant correlation-ship (p<0.01) between DPPH radical scavenging activities and polyphenolics. This indicated that polyphenolics should act as active components in flowers. Carmine rose was a good scavenger to the three kinds of free radicals and the scavenging activities of 1.00mg fresh rose flowers on DPPH’ was equal to 18.74 μ g Vc.Several effect factors were tested as follows: (1) There was significant correlation-ship (p<0.01) between three radical scavenging activities of a variety of rose buts and flowers; (2) The contents of polyphenolics and flavonoids in different developmental stage were decreased, as well as the scavenging activities to the three radicals. But the mean weight of each fresh flower was highest in developmental stage 6; (3) The scavenging activities to the three radical scavenging activities increased following the increasing contents of polyphenolics, flavonoids and Vc at the beginning of short-term storage. Low-temperature treatment was an effective measure for preserving antioxidants; (4) The results proved that boiling water was the best solvent for extracting main components of rose, compared with different solvents such as acetone, water and ethyl acetate on the effect of ultrasound; (5) The scavenging activities of aqueous extracts increased when increasing its extracting temperature. Both scavenging activities and the contents of polyphenolics had no significant difference (P>0.05) after extracting for 30 min at 100 ℃; (6) The effects of various concentration of extracts on the DPPH’were examined, and the relationship betweenconcentration and scavenging activities had a linear dose-response relationship (r=0.991; y =15.792x + 14.745); (7) pH 5 was considered to be the best extracting pH values, which had a significant difference at 5% level with others and the scavenging activities were limited in alkaline conditions.18 compounds had been identified by gas chromatography/mass spectrometry, among which 75.014 percentages had hydroxyl group. The aqueous extracts were fractionated on sephadex G-100, polyamide, sephadex LH-20 and CM-52 columns using water/ethanol as the solvent. The results showed fractions separated from CM-52 column possessed a remarkable antioxidant activity compounds, which still existed high scavenging activities after 120 days in 4℃ storage.更多还原