Flavonoids And Phenolic Acids Of Trollius Chinensis Bunge And Their Biological Activities

Flos Trollii is the dried flower of Trollius chinensis Bunge,a perennial herb of Ranunculaceae,which is widely used in the treatment of pharyngeal inflammatory diseases.Previous studies have shown that total flavonoids and total phenolic acids have certain anti-inflammatory effects,but its effective substances and mechanism need further study.At present,the research on flavonoids of Trollius chinensis Bunge mainly focuses on the representative components of orientin and vitexin,and other active flavonoids need to be further explored.The study of phenolic acids of Trollius chinensis Bunge is insufficient,only 9 phenolic acids were found,and other phenolic acids and their activity and mechanism need further study.Therefore,Trollius chinensis Bunge was selected as the research object in this paper to find more active flavonoids and phenolic acids with new structure and clarify its mechanism.Through polyamide,reversed-phase column chromatography and recrystallization,46 compounds were isolated and purified from the 70%ethanol extract of Trollius chinensis Bunge.The HR-ESI-MS and NMR spectroscopy were used to analyze the structures of the compounds.Among them,compounds 1-35 are flavonoids,compounds 36-46 are phenolic acids,compounds 1,2,3,4,5,6,36,37 are new compounds.Based on the study of chemical constituents,the anti-inflammatory effects of 46 isolated compounds were studied by using LPS-induced RAW264.7 macrophages to establish an inflammatory model,so as to provide modern pharmacological basis for the clinical treatment of inflammatory diseases and to explore the material basis of antiinflammatory activities of Trollius chinensis.NO production in RAW264.7 macrophages was detected by Griess method,and the results showed that compounds 2 and 34 could significantly inhibit NO production.Western Blotting results showed that compounds 2 and 34 significantly decreased iNOS protein expression.In addition,the inhibitory effect of isolated phenolic acids on α-glucosidase was studied in this paper.The results showed that compounds 36 and 39 had significant inhibitory effect on α-glucosidase,and the IC50 values were 25.96μM and 3.14μM,respectively.The results of α-glucosidase inhibitory kinetics experiments showed that the inhibitory effects of compounds 36 and 39 on α-glucosidase were reversible.The inhibitory type of compound 36 was noncompetitive,and the inhibitory type of compound 39 was uncompetitive.The interaction mechanism of compounds 36 and 39 with a-glucosidase was further studied by fluorescence quenching,CD and molecular docking.This paper preliminarily revealed the material basis and mechanism of traditional anti-inflammatory activity of Trollius chinensis Bunge,and found that phenolic acids had significant α-glucosidase inhibitory activity,which provided a reference for further rational development and utilization of Trollius chinensis Bunge.