Study On The Purification Of Total Flavonoids From Cistanche Deserticola L. By MOFS

Cistanche deserticola,a perennial herb of Orobanchaceae family,Cistanche genus,is a common traditional Chinese medicine.Flavonoids are one main kind of effective components in C.deserticola,and have different pharmacological activities:anti-inflammatory,immunomodulatory,antioxidative,anticancer,antibacterial,antiviral and antitumor effect.In this paper,a new material,metal organic frameworks(MOFs),was used to enrich and separate the total flavonoids from C.deserticola,so as to extend the application scope of MOFs and provide a new way for the separation and purification of effective components of Chinese medicine.Flavonoids were extracted from C.deserticola by ethnol.The best parameters of extract technology were optimized using single factor experiment and orthogonal analysis.Ethanol extraction optimum extraction conditions were 70%ethanol concentration,solid-liquid ratio 1:30,2 h of reflux time,temperature 40℃.Total flavonoids concentration under this condition is 9.33%.In this study,metal-organic frameworks(MOFs)were Solvothermally synthesized,and the synthetic MOFs characterized by SEM,PXRD,IR and TG.The structure of synthetic MOFs was confirmed by XRD and FT-IR spectrum.The five kinds of MOFs synthesized were of good crystal form and high purity.According to the result of TG,the synthetic MOFs displayed better thermo-stabilization.The static adsorption and desorption behaviors of five kinds of MOFs and eight macroporous resins for enriching Total flavonoids from C.deserticola were investigated.For MOFs:MIL-101-Cr and[Zn(nicotinate)2]n were selected as the favorable MOFs,.according to adsorption capacity and desorption rate.For eight macroporous resins,the adsorption performance and desorption conditions of eight macroporous resins for C.deserticola extracts flavonoids was researched.The results showed that the D101 resin was the optimal due to its highest separation and purification of the total flavonoids from C.deserticola.The optimum adsorption conditions were solution concentration 1.56 mg mL-1,pH=5.0.The optimum elution condition was 70%ethanol.Comparing the two MOFs materials with D101 macroporous resin,the maximum adsorption capacity of MIL-101(Cr),[Zn(nicotinate)2]n and D101 macroporous resin to the total flavonoids was 56.48 mg·g-1,62.91 mg ·g-1 and 13.20 mg·g-1,respectively,while the maximum desorption rates were 45%,57.31%and 63.48%,respectively.Finally,the content of total flavonoids after purification by MIL-101(Cr)and[Zn(nicotinate)2]n increased from 6.55%to 45%and 48.23%,respectively.The content of flavonoids purified by D101 resin increased from 5.66%to 60.5%.The results show that the adsorption capacity of MOFs is strong,which is 4～5 times as large as that of macroporous resin;desorption capacity and purification capacity slightly worse than D101 macroporous resin.But,in terms of material consumption,economic cost and process,MOFs can be used as a potential separation and purification method for total flavonoids of C.deserticola.