Biomimetic Synthesis Of The Stilbene Dimers

Naturally occurring oligostibene is a type of polyphenol oligomer with complexstructures, polymerized with different types and degrees. It attracts increasing attention in thefield of natural product in recent years due to the multi-faceted biological activities, such asanti-inflammatory, anti-oxidant, anti-bacterial, anti-tumor, and so on. The diversity of thecoupling position of the monomers and stereochemistry resulted in the complexstructure,more polarity, and the difficulty of the total synthesis for the oligostilbene.Therefore, the biomimetic synthesis based on the oxidative coupling reaction is one of themain routes in the preparation of oligostilbenes.The thesis reviewed the application of MoCl5used as catalyst in general organicchemistry, and the application used as oxidant in the oxidative coupling reaction of phenoliccompounds. The oxidative coupling reaction of resveratrol with AgOAc as an oxidant inmethanol was investigated, and the oxidative coupling reactions of oxyresveratrol usingAgOAc and MoCl5as oxidants in methanol were preliminarily explored.11stilbene dimericderivatives were obtained from these reactions, and their structures were determined on thebasis of spectral analysis. Among them, six compounds were identified as new ones.Refered to the method reported in the literature, the oxidative coupling reaction ofresveratrol with AgOAc as an oxidant in methanol was futher investigated. Monitored byHPLC, the effects of catalyst, time, temperature, and concentration were studied, and threetypes of compounds were determined as main products. Seven resveratrol dimeric derivativeswere isolated from the reaction mixture through the methods of silica gel columnchromatography, and HPLC preparation. Their structures and relative configurations weredetermined by spectral analysis (NMR, UV, IR, MS), and their plausible formationmechanisms were also discussed. Among them, compounds3,4, and5were new dimericderivatives, and the natural products of6and7with the skeleton of indane were artificiallysynthesized for the first time.The oxidative coupling reaction of oxyresveratrol using AgOAc as an oxidants inmethanol was preliminarily explored. A new oxyresveratrol dimer8was isolated from thereaction mixture. Its structure was determined based on the spectral analysis, and itsformation mechanism was discussed.The oxidative coupling reaction of oxyresveratrol using MoCl5as an oxidant inmethanol was studied. Compounds9,10, and11were obtained from the reaction mixture,and their structures were identified on the basis of spectral method. Compounds9and10were new oxyresveratrol dimeric derivatives. The experiment indicated that thepolymerization method of oxyresvertrol with MoCl5as oxidant was different from others.Pharmacological testing on anti-inflammatory, anti-oxidant, anti-diabetic is now inprogress, and only the biological results of anti-inflammatory was obtained.