Spectral Analysis Of Luteolin And Prediction Of Coreopsis Tinctoria Inhibiting α-glucosidase Activity

Coreopsis tinctoria,rich in a variety of natural chemical components,has a variety of pharmacological components and lipid-lowering,antihypertensive and other strange effects,so that the development and utilization of Coreopsis tinctoria is more extensive.In addition,Coreopsis tinctoria can be used as a natural inhibitor,and Coreopsis tinctoria extract has a good inhibitory effect on α-glucosidase.However,the prediction of inhibition of α-glucosidase activity by Coreopsis tinctoria extract has not been reported.Luteolin is a kind of flavonoids with a variety of pharmacological effects.Drugs prepared with luteolin as the main component are often used to treat diseases,so it is of great significance for the enrichment and detection of luteolin.The common luteolin method has the disadvantages of slow analysis speed and complex equipment,so it is particularly important to use convenient and rapid analysis method to detect luteolin.Spectral analysis is a common technical method for detecting substances.Near infrared spectroscopy（NIRs）and fluorescence spectroscopy（FS）are two spectral analysis methods.NIRs analysis is characterized by fast analysis speed and non-destructive sample.FS analysis has good selectivity and high sensitivity,which is widely used in active component analysis and medicinal and edible plant analysis.In this paper,luteolin was detected and analyzed by spectral technology,and the inhibitory effect of Coreopsis tinctoria extract on α-glucosidase was investigated.The relationship between the inhibitory activity of Coreopsis tinctoria extract on α-glucosidase was predicted by ensemble spectral technology.The main contents are as follow.（1）In order to enrich luteolin in dilute solution,imidazole ionic liquid was used as raw material to prepare adsorbent,and a NIRs method based on CARS variable selection was established for rapid determination of luteolin.The effects of adsorbent dosage,p H value and oscillation time on the adsorption effect were investigated.The adsorption capacity was measured and the adsorption isotherm model was determined.NIRs were used to determine the spectra of enriched samples,and the calibration model of luteolin was established by combining the CARS variable screening method with the partial least squares（PLS）method.The model was verified by spectral pretreatment method,and the reliability of the model was realized.It can be used for sensitive and rapid detection of luteolin in dilute solution.（2）In order to establish a rapid detection method for luteolin,biomass fluorescent carbon dots were prepared by hydrothermal synthesis method with common biomass pomegranate juice in Xinjiang as raw material for the detection and analysis of luteolin.The morphology and luminescent properties of biomass carbon dots were studied by transmission electron microscopy（TEM）,infrared spectroscopy（IR）,ultraviolet-visible spectroscopy（UV-Vis）and fluorescence spectroscopy（FS）.The effects of temperature and p H on carbon dots were explored,and the fluorescence quantum yield was measured.In addition,the effect of carbon dots on selective fluorescence enhancement of luteolin was studied,and the influence of external conditions on the determination system was explored.The precision,reproducibility and selectivity of the determination system were investigated.A convenient fluorescence analysis method for the determination of luteolin was provided.（3）In order to study the inhibitory prediction of medicinal and edible plants on α-glucosidase,α-glucosidase is one of the most important enzymes causing hyperglycemia,and snow chrysanthemum extract can be used as a natural inhibitor of α-glucosidase.Therefore,a new method based on near infrared spectroscopy（NIRs）was proposed to predict the inhibitory activity of Coreopsis tinctoria extract on α-glucosidase.The absorbance of the inhibition system was determined by UV spectroscopy to study the inhibitory activity of cinerarius extract onα-glucosidase.The nearinfrared spectra of the solid samples of Coreopsis tinctoria were collected,and the partial least squares（PLS）method was used to establish a rapid prediction model of inhibitory activity by selecting the spectral preprocessing and optimizing the spectral band,which could realize the rapid prediction of α-glucosidase inhibitory activity by Coreopsis tinctoria extract.In this paper,NIRs and FS were used to realize the detection and analysis of low concentration luteolin in dilute solution,and the results were good.Rapid prediction ofα-glucosidase inhibitory activity of Coreopsis tinctoria extract was achieved by NIRs.The model is reliable and can be used to predict the inhibition of Coreopsis tinctoria extract.