Concise Syntheses Of Xanthones And Their Clearance Effects Against Nitrite

Objectives：To synthesize a series of xanthones with concise method. To screen the clearanceeffects against nitrite of all the prepared compounds. In the purpose of searchingcandidate drug to prevent cancer through investigation of structer-activity relationshipand clearance mechanism.Methods:1. Synthetic method: thirteen xanthones (3a-3m) were synthesized under the catalysisof Eaton’s reagent applying phloroglucinol and substituted salicylic acids asstarting materials. The reaction mechanism has also been discussed.2. Activity test: The clearance effections of all the prepared xanthones against nitritehave been investigated by UV spectrophotometry. Their structure-activity relation-ship have also been discussed.3. Verification of clearance mechanism: Assuming clearance mechanism based onthestructure of xanthone, and the mechanism was verified by HPLC and ESI-MS.Results:1. Thirteen xanthones (3a-3m) were synthesized under the catalysis of Eaton’sreagent. All the prepared xanthones were characterized by1H NMR,13C NMR andMS spectra. And the reaction mechanism has been discussed.2.All the tested xanthones have obvious clearance effects against nitrite at theconditions of pH3.3b,3f,3g,3h,3e are identified as the most active compoundswith clearance rate up to30.0%. Mechanism of clearance was verified.thatxanthones capture NO+(reactive intermediates of NO2-) to nitro xanthones.Conclusion:Xanthones have obvious clearance effects against nitrite and they are expected tobecome drug candidates for cancer prevention after structural modification.