Extraction Of Flavonoids From Wild Tulip And Study Of Biological Activity

Tulipa L.is a perennial herb of the genus Tulipa in the family Liliaceae.The Wild Tulip is a unique wild germplasm resource in Xinjiang and is a Grade II protected plant.According to the second volume of the Xinjiang Journal of Medicinal Plants（1979 edition）,Tulipa Ili has some medicinal value.In recent years,research on Wild Tulip has focused on biological characteristics and cultivation techniques.Although studies have found that the plant has a variety of active ingredients,the analysis of its active ingredients and its medicinal value are few and not deep enough.In this thesis,we studied the ultrasonic-assisted extraction of flavonoids from Wild Tulip,and determined the optimal process parameters;we also investigated the biological activities of the extracts from flowers,stems,and leaves of Wild Tulip through antioxidant,antibacterial,and enzyme inhibitory activities.The results of the study can provide a basis for the development and utilization of the medicinal value of Wild Tulip.The main findings and conclusions of the study are as follows:（1）The above-ground parts of Wild Tulip were used as the experimental test material to extract flavonoids from Wild Tulip using ultrasonic-assisted technique.The best extraction conditions were determined by single-factor experiments as liquid to material ratio 40:1（m L/g）,ethanol volume fraction 60%,extraction time 30 min,extraction temperature 70℃,and extraction power 400 W.Based on this experiment,a regression equation prediction model was established using the response surface method.The optimal extraction parameters were obtained as follows:liquid to material ratio of 40:1（m L/g）,ethanol volume fraction of 55%,extraction time of 28 min,extraction temperature of 70℃,and extraction power of 400 W.According to the optimized The average extraction rate of total flavonoids of Wild Tulip was3.75%in three parallel validation tests.（2）The flavonoids in different parts of flowers,stems and leaves were extracted by ultrasonic-assisted extraction method using Wild Tulip harvested in Qapqal Xibe Autonomous and Xinyuan counties as experimental test materials（test article numbers 1-6）.The order of magnitude of flavonoid content in different parts was:flower>leaf>stem.The effect of extracts on DPPH·,ABTS⁺·,·OH and NO₂^-scavenging as well as Fe³⁺total reduction capacity was studied by five in vitro antioxidant evaluation systems.The results of the antioxidant activity experiments showed that the antioxidant capacity of the extracts of each part showed a certain correlation with the concentration within the investigated concentration range,and the higher the concentration of flavonoids,the stronger their antioxidant activity;because of the different origins and parts,the antioxidant capacity appeared to be mixed,in which the flavonoids of each part of the samples collected in Qapqal Xibe Autonomous County were relatively higher than those of the samples collected in Xinyuan County.The antioxidant capacity of the extracts was 88.29%,99.67%,57.02%,83.35%and 1464.02μmol/L for DPPH·,ABTS⁺·,·OH and NO₂^-scavenging capacity as well as Fe³⁺total reduction capacity in the investigated concentration range.（3）Wild Tulip from Qapqal Xibe Autonomous and Xinyuan counties were used as test materials,and Escherichia coli,Bacillus subtilis and Staphylococcus aureus were selected as test strains to investigate the antibacterial activity of flavonoids in extracts from flowers,stems and leaves of Wild Tulip from both counties.The experimental results showed that the inhibition effect of tulips harvested from Qapqal Xibe Autonomous County was better than that of Xinyuan County,and the inhibition ability of different parts of Wild Tulip harvested from Qapqal Xibe Autonomous County were leaves>stems>flowers at the same concentration,while the inhibition ability of different parts of Wild Tulip harvested from Xinyuan County were leaves>flowers>stems from the largest to the smallest.（4）The composition of flavonoids in the extracts of different parts of Wild Tulip flowers,stems and leaves collected from two locations was analyzed by liquid-mass spectrometry.79flavonoids were detected in the Wild Tulip flowers from Qapqal Xibe Autonomous County in sample No.1,68 flavonoids may be contained in the Wild Tulip stems from Qapqal Xibe Autonomous County in sample No.2,70 flavonoids were detected in the Wild Tulip leaves from Qapqal Xibe Autonomous County in sample No.3,and 75 flavonoids were detected in Wild Tulip flowers from Xinyuan County,69 flavonoids were detected in Wild Tulip stems from Xinyuan County in sample No.5,74 flavonoids were detected in Wild Tulip leaves from Xinyuan County in sample No.6,and 48 flavonoids were present in the six samples together.The results showed that the flavonoids contained differently due to different origins and parts,the biological activity presented will be different.