Efficient Detection And Identification Of Flavonoid Analogues

Ningxia wolfberry plays an important role in Chinese traditional medicine.It contains rich flavonoids,which can prevent cancer,anti-oxidation and anti-aging,relieve cough and asthma,expand coronary artery,lower blood cholesterol,enhance heart contraction,reduce pulse rate,prevent Gout and other biological activities.The flavonoids,which are formed by the secondary metabolism of the human body,are small molecules flavonoids,which are more easily absorbed and utilized by the human body and have higher activity.Small flavonoids have many kinds of structures and similar structures.Fingerprint identification can promote the molecularization of traditional Chinese medicine components.This paper utilizes the characteristics of SERS technology for trace and fingerprint detection.In this study,the flavonoid analogues such as quercetin were used as the research object to optimize the substrate and experimental conditions of SERS technology.The feasibility of separation and detection of flavonoids by TLC-SERS was discussed.The barcode is used to simultaneously analyze the chemical structure and antioxidant activity of the functional ingredients.The research conclusions are as follows:(1)Optimize the SERS detection substrate and experimental conditions.The silver dendrite obtained by the reaction time of 20 s has the best reinforcing effect and stable performance.The Raman instrument has the best laser scanning time of 10 s and can obtain complete sample information while protecting the sample.(2)The TLC-SERS combination technique can distinguish and identify flavonoid analogues.Separation and detection of quercetin,luteolin,myricetin and kaempferol by TLC-SERS combined technique can detect 0.317 ng of the test substance.The mixture was separated using a developing solvent in the form of petroleum ether:ethyl acetate: formic acid = 17:13:0.3,and observed under ultraviolet light(254 nm and 365 nm).The SERS barcode method can be used to visually identify a single substance and a mixture of two substances.The flavonoid analog spectrum was well distinguished using the PCA method.(3)The SERS barcode contains both molecular structure and antioxidant activityinformation.The barcodes converted by SERS second-order derivative map were used to identify the eight flavonoid analogues in sputum,as well as the molecular structure and antioxidant activity of rutin,chlorogenic acid and p-coumaric acid.The bar code can easily and intuitively reflect the important information contained in the spectrum.The order of antioxidant capacity of 11 substances is quercetin> luteolin>flavonoid> kaempferol> baicalein> rutin> chlorogenic acid> myricetin> For coumarinic acid > apigenin > chrysin.The research results provide a new idea for the molecularization of traditional Chinese medicine active ingredients,and expand the application of SERS technology in the field of traditional Chinese medicine.If combined with good separation technology and rapid barcode identification technology,complex Chinese medicine ingredients will be simple,fast and efficient.Detection.