Polyphenolic Composition Of Chinese Propolis

Propolis is resinous and adhesive natural substance collected by honeybees from buds and leavesof plants, normally mixed with beewax as well as pollen and so on. Propolis possesses antioxidant,antibacterial, antiviral, immunomodulatory, and antiproliferative properties, attributed to the presence offlavonoids, phenolic acids, and its esters. Therefore, polyphenolics in propolis from China were studiedsystematically in this thesis.HPLC method of polyphenols of ethanol extract of propolis had been established.55phenoliccompounds in propolis were separated by HPLC-PDA, and identified and compared the UV and MSspectra with authentic standards by HPLC-MS, including30favonoids,20phenolic acids and theiresters and5glycerides.27polyphenols of105propolis samples were quantitatively analyzed, and all propolis samplesexcept those from Yunnan contained many kinds of flavonoids, phenolic acids and their esters. Themajor flavonoids were pinobanksin-3-O-acetate，chrysin，pinocembrin，pinobanksin，5-methoxypinobanksin and galangin. The dominant phenolic acids and their esters were caffeic acid phenethylester, P-coumaric acid, caffeic acid, isoferulic acid,3,4-dimethoxy cinnamic acid, ferulic acid andcinnamic acid. Propolis samples collected from central and northern areas of China presented the higherlevel of total polyphenol contents, while the west area had the lower level.Propolis of Chinese mainland was divided into five categories based on main constituents andHPLC chromatography features. The average amount of total detected polyphenols of the first categorysamples was176mg/g,81%of them on favonoids on average, and almost all of the first categorysamples had the complete components. The average amount of the total detected polyphenols from thesecond category samples were173mg/g,90%of them on favonoids,5favonoids among thempresented high levels. The average amount of the total detected polyphenols from the third categorysamples were130mg/g,85%of them on favonoids,4favonoids among them presented high levels.The average content of total polyphenols from the fourth category samples were85mg/g,74%of themon favonoids, and this category samples contain high levels of P-coumaric acid. In addition, the fifthcategory samples are those from Yunnan province which almost had few polyphenols and3propolissamples from Guizhou and Hubei province which had abundant glycerides. Chromatographicfingerprints of every category of propolis samples were established, and chromatographic fingerprintssimilarity between the first three category propolis samples was more than0.80. Fingerprints similaritybetween the fourth category samples and the first third category samples was around0.55. This mayindicated that the fourth category samples had great difference with the first three category propolissamples.Similarity between HPLC chromatogram of Populus canadensis (Populus canadensis Moench)poplar bud extracts and that of propolis was higher than other plant extracts, including other types ofpoplar, brich, willow, pine. Bud exudates of Populus canadensis are the main source of Chinese propolis, and propolis samples with glycerides might be from Populus tomentosa Carr.Polyphenols in commercial propolis soft capsules from Beijing were analysised by HPLC-PDA.The result indicated that the components and contents of some samples of propolis soft capsules weresimilar to those of polyphenolics in raw propolis.