ABSTRACT
Objective::To compare the adsorption characteristics of different macroporous adsorption resins for the total flavonoids in Epimedii Folium, clarify the adsorption mechanism, and screen the optimal resin for the purification of total flavonoids in Epimedii Folium. Method::Taking the adsorption and desorption capacities of the total flavonoids in Epimedii Folium and five representative flavonoids (epimedin A, epimendin B, epimendin C, icariin, baohuoside Ⅰ) as indexes, static adsorption and dynamic adsorption experiments were conducted to compare the adsorption characteristics of five macroporous including HPD100, HPD600, AB-8, X-5 and D101.The adsorption kinetics of the selected resin was studied by using the pseudo-first-order, pseudo-second-order kinetic models and intraparticle diffusion model, and the thermodynamic process was analyzed by using the Langmuir and Freundlich isothermal adsorption models, which explored the adsorption mechanism of resin from the perspective of physical chemistry. Result::HPD100 macroporous resin had a better adsorption and desorption properties than the others. The adsorption process of HPD100 macroporous resin for total flavonoids in Epimedii Folium and five representative flavonoids conformed to the pseudo-second-order kinetic model. The adsorption thermodynamic process of HPD100 resin for total flavonoids of Epimedii Folium conformed to the Freundlich model, and for the sum of five representative flavonoids conformed to the Langmuir model. The adsorption process of HPD100 resin for total flavonoids in Epimedii Folium was the exothermic process dominated by physical adsorption, and the optimal adsorption temperature was 25 ℃. Conclusion::HPD100 macroporous resin has large adsorption capacity, easy desorption and clear adsorption mechanism, it is suitable for isolation and purification of total flavonoids in Epimedii Folium.
ABSTRACT
To optimize the formulation and preparation process of icaritin-coix seed oil microemulsion(IC-MEs) based on quality by design(QbD) concept. IC-MEs were prepared by water titration. Firstly, the risk factors that may affect the quality of IC-MEs were evaluated. Then Plackett-Burman design was used to screen out prescription factors and process parameters that had a significant effect on the indicators. Finally, Box-Behnken design was used to optimize the prescription ratio of IC-MEs. Through the risk assessment and Plackett-Burman design, three formulation factors [drug loading efficiency, the ratio of mixed-oil(coix seed oil-Glycerol tributyrate) to mixed-surfactant(HS15-RH40) and water addition] were determined as the key factors affecting IC-MEs. The regression model established by Box-Behnken design had a good predictability. The optimal formula was as following: the drug loading efficiency of 0.92%, the ratio of mixed-oil(coix seed oil-glycerol tributyrate) to mixed-surfactant(HS15-RH40) of 4∶6, and the water addition of 5.7 mL. According to this prescription, IC-MEs were prepared, and its encapsulation efficiency after 1 week was 92.45%±1.00%. Therefore, the stability of IC-MEs could be improved by optimizing prescription and process parameters of IC-MEs based on the QbD concept, which can provide certain reference value for the future development of IC-MEs.
Subject(s)
Coix , Emulsions , Flavonoids , Plant OilsABSTRACT
Objective: To prepare the immobilized snailase on cross-linked nano-SiO2, characterize its physicochemical properties, and investigate the optimal conditions of hydrolyzing icariin to baohuoside Ⅰ and enzymatic properties. Methods: The snailase was immobilized on the glutaraldehyde cross-linked nano-SiO2 by covalent coupling method. The immobilization conditions were optimized using the relative enzyme activity as the test index. Transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR), and elemental analysis methods were used to characterize the physicochemical properties of immobilized snailase. Using icariin as the substrate and free enzyme as the control, the optimal enzyme conditions, enzymatic kinetic parameters, recyclability, and thermal stability of the immobilized snailase were also investigated. Results: The optimal mass ratio of enzyme to carrier was 1:3 and the optimal immobilization time was 6 h for the preparation of the immobilized snailase. The optimum hydrolysis conditions of the immobilized snailase were as follows: pH 5.0, conversion temperature 60 ℃, mass ratio of enzyme to substrate 1:2, and transformation time 12 h. The Vmax and Km of the immobilized snailase was 0.43 μg/min and 0.78 mmol/L, respectively. After repeated use for 5 times, the residual relative enzyme activity of the immobilized snailase maintained above 70%. Conclusion: The immobilized snailase on cross-linked nano-SiO2 has high mechanical strength, strong stability, and good reusability. It can hydrolyze the icariin to the baohuoside Ⅰ with a better activity. The hydrolysis process was simple, easy, and suitable for industrial production.