Structural Analysis And Antioxidant Activities Of Polysaccharide Isolated From Carthamus Tinctorius L

In this paper,using Tacheng safflower?Carthamus tinctorius L.?as experimental material,the extraction process of Carthamus tinctorius L.polysaccharides?CTLP?was optimized,and different components of CTLP were purified.The structure and antioxidant activity of CTLP were determined.Physical and chemical modification methods were selected to modify CTLP and evaluate their antioxidant activity.The results are as follows:1.Extraction of CTLPThe ratio of material to liquid,extraction time,extraction power and extraction temperature were selected as the influencing factors,and the yield of CTLP was the response value.The multiple regression fitting equation obtained was as follows:Y=16.24-0.28A+0.23B+0.14C+0.14D-0.22AC-0.16AD-0.062BD-0.089B²-0.29C²-0.21D².Under the optimum extraction conditions?1:15,50 min,135.75 W and 65.5??,the yield of CTLP was 16.85%.2.Structure Analysis and Antioxidant activity of CTLPCTLP was obtained by purification.According to the elution curve,CTLP-1 and CTLP-2 were collected.The structure of CTLP was analyzed by HPLC,Fourier transform infrared spectroscopy,SEM and nuclear magnetic resonance.The antioxidant activity was determined as well.CTLP was 6400 Da,composed of fructose,arabinose,glucose and galactose?8.1:4.6 and 3.2:1?.CTLP had good antioxidant activity and concentration-dependent.Its hydroxyl radical scavenging activity was the strongest,occupied 69.5%(5 mg mL^-1).CTLP-1 was 5900 Da,which was composed of arabinose,glucose and galactose,and the mass molar ratio was 6.7:4.2:1.The backbone of CTLP-1 was?1)-?-GalAp-?1?4?-?-Arap-?1?2?-?-Glup-(4?.The DPPH radical scavenging activity of CTLP-1 was the strongest,occupied 65.2%(5 mg mL^-1).CTLP-2 was 8200 Da,composed of arabinose,glucose and galactose,and the mass molar ratio was 16.76?4.28?1.The backbone of CTLP-2 was?1)-?-Galp-?2,6?1?-?-Arap-?4,6?1?-?-Glup-(3?.The DPPH radical scavenging activity of CTLP-2 was the strongest,which was 60.5%(5 mg mL^-1).3.Modification and Antioxidant activity of CTLPUltrasonic modification,H₂O₂ oxidation,NaNO₂ degradation,carboxymethylation,acetylation and sulfation were selected to modify CTLP and evaluate their antioxidant activity.The results were as follows:The antioxidant activity of physical modification was lower than that of chemical modification.In physical modification,NaNO₂ degradation had the greatest effect on Fe²⁺chelating activity,hydroxyl radical scavenging activity and DPPH radical scavenging activity.In chemical modification,carboxymethylation had the greatest effect on hydroxyl radical scavenging activity,acetylation had the greatest effect on hydroxyl radical scavenging activity and sulfation had the greatest effect on Fe²⁺chelating activity.