| Aquilaria sinensis(Lour.)Spreng.is the source plant of agarwood,one of the most famous medicinal herbs and spices.The wild Aquilaria resources in China are severely damaged and nearly endangered.As a sustainable resource,various medicinal ingredients have been successfully identified and extracted from Aquilaria leaves.According to reports,Aquilaria leaf is rich in mangiferin and it has anti-inflammatory,anti-tumor,anti-oxidation,blood sugar and blood lipid lowering effects.Due to its poor solubility in water and low bioavailability,its application is restricted.At present,the related research of mangiferin mainly focuses on the pharmacological activity,and there are few related studies on the extraction,separation,purification and improvement of water solubility of mangiferin.This study analyzed the spatiotemporal changes of the content of mangiferin in Aquilaria leaf.Mangiferin was efficiently extracted,separated and purified,and the supercritical antisolvent(SAS)technology was used to improve its water solubility and increase the bioavailability.Research results are as follows:(1)This paper measured the change of flavone and magniferin capacity in Aquilaria leaves from different trees with different maturity,in different times with different storage lengths,in Sanya&Maoming regions in China.The results showed that in Aquilaria sinensis leaves,the overall capacity of flavone and magniferin are in direct proportion to the production of magniferin.The flavone had a low of 8.021%in January and a high of 10.830%in July,and the magniferin had a low of 2.24%in January and a high of 3.30%in May.The magniferin's production reached a low of 11.68mg in January and a high of 18.85mg in May.The average percentage of magniferin in new leaves(3.69%)was significantly higher than mature leaves(2.44%),over-mature leaves(1.60%)and old leaves(0.53%).Magniferin capacity in annual Aquilaria leaves was fluctuant at different times of the year while that of biennial and other leaves was not as much.Speaking of region,the average capacity of magniferin in Sanya(2.94%)was higher than Maoming(2.70%).Both regions' capacity within a year was distributed with two peaks:Sanya's first was in May(3.75%)and the second in November(3.04%)while Maoming's was in March(3.16%)and September(2.88%).Magniferin's capacity,when stored in a cool,dry place without sunlight,had a fluctuation within 0.02%throughout the year.(2)This paper used micellar method and microwave-ultrasound technique to extract magniferin from Aquilaria leaves,and it was preliminarily purified by macroporous resin,and then further purified by the antisolvent precipitation method.The results are as follows:By controlling variable and response surface methods,we refined the extraction process,and verified through experiment.The ideal condition:alkyl polyglucoside's mass fraction was 0.9%,and the extraction time was 7 min.The microwave ultrasonic power was 408 W,while the concentration of solution was 1:44.The maximum extraction rate of magniferin was 3.229%(32.229 mg),with a margin of error of 0.9%.The purification conditions of the macroporous resin are:choose the 2.5BV AB-8 macroporous resin column,the feed rate is 1 ml/min,and leave it to stand for 120 min after the sample is completely loaded.13%BV was eluted with 40%ethanol solution,and the purity of mangiferin was 73%with 57.31%yield.The effects of deposition time,deposition temperature,concentration of mangiferin crude solution,volume ratio of solvent to inverse solvent on the purity and yield of mangiferin were investigated by single factor,The optimum purification process was determined:The deposition time is 3 min,the deposition temperature is 35?,the concentration of the crude mangiferin solution is 35 mg/mL,the volume ratio of solvent to antisolvent is 1:15,and the purity of the mangiferin is 98.13%and 81.34%.(3)This paper successfully produced magniferin sub-micron powder by using Supercritical Anti-Solvent(SAS)technique,and refined the process through Orthogonal Array Design(OAD).The results are as follows:regarding the effects on magniferin's solubility of all the elements,crystal compressibility>concentration of magniferin solution>temperature of crystalization>inflow rate of the solution.When these elements are 20 MPa,51?,23 mg/mL and 10 mL/min,respectively,the solubility reaches its maximum value of 0.6413 mg/mL,with the radius of the particle 532.8 nm.(4)This paper analyzed the physical and chemical properties of magniferin's extract and its sub-micron powder,with the same chemical structure.82.43%of the magniferin sub-micron powder was in indefinite structure,with a crystallization degree of 12.57%.The solubility of magniferin sub-micron powder was also higher than its original extract(610 ?g/mL to 146?g/ml,a ratio of 4.39.)While artificial gastric juice has a saturated solubility of 206 ?g/ml,about 2.1 times of its original extract(98 ?g/ml),artificial intestinal juice has a saturated solubility of 119?g/mL,about 2.25 times of its original extract(53 ?g/ml).According to vitro release study,magniferin sub-micron powder's extraction rate in artificial gastric juice is about 1.19 times of it's original extract,while the figure in artificial intestinal juice is about 1.30.(5)Through the comparison among the DPPH free-radical scavenging capacity between magniferin's extract and its sub-micron powder,the reduction capacity to the ABTS free-radical scavenging capacity,and the reduction capacity to potassium ferricyanide,the results show that the reduction capacity of magniferin sub-micron powder is way higher than its extract,with 1.66 times of the DPPH free-radical scavenging capacity,and 1.45 times of vitamin-c capacity.When the solubility reached 0.4mg/ml,the ABTS free-radical scavenging capacity ratio was about 1.33:1—almost equal to the clearance rate of vitamin-C.Besides,the ratio of its reduction capacity of Fe2+ was 2.77:1.(6)This paper focused on plenty of research regarding the magniferin's distribution status and biological availability in every body tissue in mice as they ingested magniferin sub-micron powder and its extract.The results are as follows:from the absorption rate in every body tissue,magniferin sub-micron powder performed better than its extract.Micron-powder's maximum capacity was about 1.61:1 of extract in the heart,2.27:1 in spleen,1.63:1 in lung,and 1.69:1 in kidney.Moreover,pharmacokinetic studies showed that the biological availability of magniferin sub-micron powder increased 2.07 times of the extract. |
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