| The receptacles of sunflower(Helianthus annuus L.)contains many active ingredients,such as polysaccharides,flavonoids,alkaloids and chlorogenic acid,which had biological activities,such as antioxidant activity,anti-inflammatory,anti-gout and anti-tumor.However,the chemical compositions and biological activities of the essential oil of sunflower receptacles(SEOs)had not been studied yet in detail.Therefore,the main purpose of this thesis is to conduct scientific research on the chemical compositions and biological activities of SEOs,which would provide more scientific basises for the utilization of SEOs.SEOs were extracted by hydrodistillation.The single-factor experimental analysis was carried out with liquid-solid ratio,ultrasonic time,distillation time and the concentration of Na Cl.The optimal extraction conditions for extraction of SEOs were obtained by the response surface methodology(RSM)as followes: liquid-solid ratio of 17.5:1(m L/g),ultrasonic time of 1.5 h,distillation time of 8 h,and 6%Na Cl.With the optimized condition,the extraction rate of SEOs was 0.42%(v/w).The SEOs were extracted from food sunflower LD5009,food sunflower SH363 and oil sunflower S606 by hydrodistillation,and the extraction rates were 0.18%,0.32% and 0.58%,respectively.A total of 101 chemical compositions were identified for three varieties of SEOs by gas chromatography-mass spectrometry(GC-MS),but the chemical compositions and content of SEOs were quite different.The antioxidant results showed that the antioxidant activities of different varieties SEOs(LD5009>SH363> S606).The analysis of the inhibitory activity of SEOs on xanthine oxidase(XO),the molecular simulation docking of the chemical compositions of SEOs and the active sites of XO showed that SEOs had a strong inhibitory effect on XO,which may be related to SEOs.The Pearson correlation coefficient(r> 0.95)showed thatγ-terpinene,(e)-citral and L-bornene were highly correlated with antioxidant activities and XO inhibitory ability.The results of antioxidant activities and XO inhibitory activity both showed that LD5009 had stronger antioxidant and XO inhibitory activities than SH363 and S606.Therefore,the SEOs can be used as a natural antioxidant product,which can also be used as a potential drug for the treatment of hyperuricemia.The antibacterial activities of SEOs were evaluated by the microplate reader.It was found that the antibacterial activities of the SEOs on P.aeruginosa and S.aureus were better than that of the main compositions of SEOs and the main compositions mixture.In the evaluation of the antibacterial activities of SEOs,it was found that the antifungal activities of SEOs were lower than that of the main chemical compositions of SEOs.The antibacterial results of α-pinene(29.93%)indicated thatα-pinene plays an important role in the antifungal process of SEOs.It was concluded that the SEOs had broad-spectrum antibacterial activities.The formula of SEOs nanoemulsion: W(SEOs nanoemulsion)= 3.32%,W(Tween-80 and Span 80)= 30.54%(v:v =72:28 emulsifier),W(ethanol and1,2-Propanediol)= 7.63%(v:v=13:12,emulsifier),W(distilled water)= 58.51%.Its average particle size was 64.76 nm,PDI was 0.189,and zeta potential was-23 m V.The prepared SEOs nanoemulsion had good fluidity,which could be miscible in water at any ratio,which was clear and transparent.Through stability investigation,it was proved that the SEOs nanoemulsion had good thermal stability,centrifugal stability and storage stability.Through the extraction of SEOs,the identification of chemical compositions,the determination of antioxidant activities,the determination of XO inhibitory activity,the determination of antibacterial activities,and the preparation of SEOs nanoemulsion,it was good for SEOs study and for farmers selection of sunflower varieties,which would provid more scientific basises of sunflower receptacles,while also being able to use waste,avoiding environmental pollution,and increasing the income of local farmers. |
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