Development Of Analytical Methods For Resveratrol Isomers And Their Applications In Formulation Studies

It is well known that resveratrol is a kind of phytoalexin which has the properties ofantioxidant and the function of lowering the prevanlence of coronary heart disease. Inthe present researches, it is reported that resveratrol is a new promosing anticancerdrug with the cancer chemopreventive activity that represent in three major stages ofcarcinogenesis such as anti-initiation, anti-promotion and anti-progression activities.Therefore the study on the resveratrol is of importance.Resveratrol exists in the glycoside form which is known as piceid and free form.Resveratrol and piceid have two isomeric forms trans and cis. It has not been reportedthat the isomers transition reaction of reavertrol and piceid and their existing form intraditional Chinese Medicine. A new analytical method based on HPLC is developedto simultaneously analyze the four isomers of resveratrol. The developed method isapplied to investigate the isomers transition reaction and determine the content of fourisomers of resveratrol in polygonum cuspidatum Sied. et Zucc.β-cyclodextrin can not only simulate the chiral macromoleculars invo such asenzymes and receptors, also can be used as an effective and safe inclusion material tomeliorate unattractive properties of drug. Hence, it is very significant to determinebinding constant of β-cyclodextrin and drugs to characterization of their interativefunction. It's hard to obtain the pure cis-resveratrol because of its unstability. Thetraditional methods for determining binding constant, such as UV-vis, NMR,fluorescence spectroscopy can not be used to determine the binding constans ofβ-cyclodextrin and cis-resveratrol. A simple method for simultaneous determiningbinding constans of β-cyclodextrin with four isomers of resveratrol has beendescribed in a dual cyclodextrin system by affinity capillary electrophoresis. Resultsindicate the formation of 1:1 inclusion complex of four isomers of resveratrol withβ-cyclodextrin respectively. Comparing the difference of the binding constants, wediscuss the nature of the interactions involved in the inclusion complexes.The application of resveratrol was limited due to it's poor solubility and unstabilityunder intensive UV light.In this paper, three kinds of cyclodextrin are studied toimprove the solubility and stability of resveratrol and the mechanism of inclusionfunction was discussed. We successfully solved those two problems mentioned above,and made some further investigation on the pharmacy of resveratrol which enlargedthe application of cyclodextrin and it's derivetives.