Design And Synthesis Of Three Biotin-Labeled Natural Product Molecular Probes

The natural products extracted and separated from traditional Chinese medicine have the characteristics of diverse structure and wide pharmacological effects,and are usually used as a lead compound to develop new drugs.Therefore,it is necessary to study their specific mechanism of action.The broadly pharmacological effects of natural products correspond to the characteristics of multiple targets,but the difficulty in determining their target proteins also hinders further research and development.Affinity-based Protein Profiling?ABPP?is the method based on the affinity between the active small molecule and the target protein,introducing a reporter group on the active small molecule,and using affinity chromatography which technology can separate target proteins.it is widely used as a very effective tool for the discovery of target proteins of natural product.In this study,three active natural small molecules extracted from traditional Chinese medicines were selected and the corresponding small molecule probes were designed and synthesized to provide an effective tool for the discovery their target proteins and the mechanism of action.The details are as follows:1.We introduced the main target protein identification methods for natural small molecules,the ABPP method and its application in the identification of natural product target proteins are highlighted.2.The biotin-labeled diosgenin probes 3 and 8 which containing a long-arm lipophilic chain and hydrophilic chain respectively were synthesized via esterification reaction,amidation reaction,substitution reaction,hydrolysis reaction from diosgenin and biotin.The antitumor activity was evaluated by the MTT method.The synthesized probe compounds and important intermediates were characterized and verified by MS,¹H-NMR and ¹³C-NMR.The results of cell viability experiments showed that the synthesized probes 3 and 8 exhibit the comparable antitumor activity to diosgenin,which lays a foundation for the discovery of the anti-tumor target protein of diosgenin.3.We separated 20?S?-protopanaxadiol and 20?S?-protopanaxatriol as the raw material of next part from Notoginseng triterpenes and sodium hydroxide and glycerol,under the condition of high temperature 235?.The two types biotin-labeled active small molecule probes were designed and synthesized according to the method of Chapter 2,using 20?S?-protopanaxadiol and 20?S?-protopanaxatriol as raw materials respectively.The the hydroxyl group of carbon 3 and 6 positions of the 20?S?-protopanaxatriol were not selective at esterification,so the biotinylated protopanaxatriols were synthesized which was substituted at the carbon 3 position and the carbon 6 position respectively.