Study On Preparation And Hypoglycemic Activity Of Vanadium-rich In Coreopsis Tinctoria Nutt.

Objective:This study aims to explore the feasibility of vanadium enrichment in Coreopsis tinctoria by artificial doping and biological vanadium enrichment,and to investigate the effect of the extract onα-glucosidase activity and the type of enzyme inhibition.Methods:（1）Established a graphite furnace atomic absorption spectrophotometry method for the determination of vanadium（V）content.4-nitrophenyl-α-D-glucopyranoside（p NPG）as the substrate and acarbose as the positive control,Establish an in vitroα-glucosidase activity inhibition model.According to the kinetic principle of enzymatic reaction,the inhibition type ofα-glucosidase activity was explored.（2）Based on the single factor experiment,the extraction process of vanadium flavonoid complex was optimized by response surface methodology with ethanol volume fraction,ultrasonic time and liquid-solid ratio as the influencing factors,the extraction rate of total flavonoids and vanadium content as the evaluation indexes.（3）Vanadium was sprayed on leaves with vanadium solution at a concentration of 50mg/L to biological enrich vanadium.C.tinctoria Blank control leaves and biological vanadium-rich C.tinctoria leaves were collected in different periods,and chlorophyll was extracted by ethanol immersion to explore the effects of vanadium on chlorophyll A,chlorophyll B and total chlorophyll content in the growth process of vanadium-rich C.tinctoria leaves.Collecting different parts of the C.tinctoria at different times and Determination of vanadium accumulation in different parts of the plant.The content of organic vanadium in the samples was investigated by using 300 Dalton（Da）dialysis bags.The difference of Absorption Spectra between total flavonoids of C.tinctoria and total flavonoids of biological vanadium-rich C.tinctoria was determined by UV and IR Spectra scanning.Results:（1）It has been determined that C.tinctoria has a strong vanadium-enriching ability,the concentration of vanadium compounds is in the range of 25～800 mg/L,and the total amount of vanadium enriched by C.tinctoria is between 1.44～30.82 mg/kg.When the concentration of vanadium solution was50 mg/L,the vanadium enrichment rate was the highest.the median inhibitory concentration(IC₅₀)of artificially vanadium-doped C.tinctoria extract onα-glucosidase was（67.08±1.15）μg/m L,and the inhibition rate increased with the increase of concentration.The experimental study of enzyme inhibition kinetics found that the extract was a mixed inhibition type.（2）Under the optimal extraction conditions of63%ethanol volume fraction,31 min ultrasonic time and 26:1 liquid-solid ratio,the extraction yield of total flavonoids was（4.56±0.03）%and the vanadium content was（10.32±0.04）μg.（3）C.tinctoria and biological vanadium-rich C.tinctoria leaf in the tendency of the content of chlorophyll a and chlorophyll b similar,but the content of chlorophyll b in each time period is lower than that of chlorophyll a,and the changes of the two contents are relatively slow.total chlorophyll content change trend and chlorophyll a and chlorophyll b content changes are similar,chlorophyll a/b values have differences in different periods,it was lower in seedling stage.In the photophase stage,the chlorophyll content of biological vanadium-rich C.tinctoria changed obviously and increased rapidly,but in the maturation stage,the accumulation of vanadium had a negative effect and the content was lower than that of the C.tinctoria.The inorganic vanadium applied by exogenous needs to be absorbed and transported to other parts of the plant through the leaf surface,and the vanadium content in the leaves is significantly higher than other parts,which can reach194.0μg/g.Comparing the extraction rates of total flavonoids from artificially vanadium-doped C.tinctoria,C.tinctoria and biological vanadium-rich C.tinctoria,the extraction rate of biological vanadium-rich C.tinctoria（4.08±0.09）%was significantly lower than that of artificially vanadium-doped C.tinctoria and total flavonoids of C.tinctoria.By the comparative analysis of UV and IR spectra,the spectral absorption characteristics of total flavonoids of biological vanadium-rich C.tinctoria were changed.The inhibitory model ofα-glucosidase activity was established in vitro,The inhibitory effect of biological vanadium-rich C.tinctoria flavonoids onα-glucosidase was stronger with IC₅₀=56.85±0.77μg/m L,which was higher than that of C.tinctoria and artificially vanadium-doped C.tinctoria total flavonase.Conclusion:（1）A method for the determination of vanadium（V）content by graphite furnace atomic absorption spectrophotometry was successfully established.Under the condition of vanadium concentration of 50 mg/L,the enrichment rate of vanadium content of C.tinctoria was the highest,at the same time,the artificially vanadium-doped C.tinctoria extract had a high vanadium enrichment rate and strong enzyme inhibitory activity,which provided a reference for the research on vanadium enrichment of C.tinctoria.（2）The optimal extraction process is feasible,and under the optimal extraction conditions,a high content of total flavonoids and vanadium extracts can be obtained from artificially vanadium-doped C.tinctoria.（3）Vanadium has a significant effect on the growth and development of C.tinctoria,and its total flavonoids have high vanadium binding andα-glucosidase activity inhibition ability.