Phenolic Compounds In Myrrica Rubra, Camellia Sinensis And Citrus Grandis

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and reversed-phase high performance liquid chromatography (HPLC) are applied to establish the methods for characterization of plant polyphenolics and to separate phenolic compounds with excellent physiological and pharmacological activities in Citrus grandis,Myrica rubra and Camellia sinensis.The results were showed as follows:1.Four polyphenolic compounds in the peel of C.grandis with excellent physiological and pharmacological activities were efficiently characterized by HPLC. Total phenolics content in the peel of C.grandis is 23.45～26.97 mg/g(catechin equivalent) and contents of 4 phenolic compouonds are 4.02～4.84 mg/g(narigin), 2.41～2.90 mg/g(p-coumaric acid),0.16～0.31 mg/g(hesperetin),and 0.010 ~ 0.012 mg/g(tangeretin),respectively.Methanol solutions extract more flavonoids than ethanol solutions do,but their total phenolic contents show no difference under 60%~ 70%concentration.2.The contents of total phenolics and extractable condensed tannins in the leaves of three types of C.sinensis(Benshan,Huangdan and Tieguanyin) were determined; in addition,the structures of condensed tannins were characterized by MALDI-TOF MS.Three types of tea had the total phenolic contents as high as 200 mg/g.The majority of condensed tannins in the three types of C.sinensis were identified as the mixtures of procyanidins and prodelphinidins with a medium level of galloylation through the linkage of A-type and B-type interflavan bonds.Meanwhile the degree of polymerizations was higher in Benshan and Huangdan than Tieguanyin.3.Contents of total phenolics and extractable condensed tannins in leaves, branches and bark of M.rubra were determined.In addition,type of condensed tannins,degree of polymerization and distribution of polymer were characterized by MALDI-TOF MS.Total phenolics content was the highest in bark(435.62±0.66 mg/g),followed by leaves(346.87±0.82 mg/g),and then branches(185.29±20.21 mg/g);while extractable condensed tannins content was the highest in leaves(256.71 ±13.76 mg/g),followed by bark(179.28±13.16 mg/g),and then branches(80.07±18.45 mg/g).Epigallocatechin-3-O-gallate was invariably the basic unit occurring in the three condensed tannins.A-type and B-type linkages were the common types among the structural units of polymers.Meanwhile tannins in leaves and branches had the larger highest degree of polymerization than bark.