title: Effective synthesis of theaflavin-3,3'-digallate with epigallocatechin-3-O-gallate and epicatechin gallate as substrates by using immobilized pear polyphenol oxidase.
abstract: In the present study, pear polyphenol oxidase (PPO) was purified, immobilized and applied for the synthesis of theaflavin-3,3'-digallate (TF3). Firstly, PPO of pear (Pyrus bretschneideri Rehd cv. Huangguan) was purified 24.36-fold in specific activity with a recovery of 6.77% by sequential use of precipitation with 70% saturated ammonium sulfate and chromatography of DEAE-Sepharose Fast Flow column. The purified pear PPO, found to be a dimer of identical subunits of molecular mass 35kDa, was then successfully immobilized onto Fe3O4/chitosan nanoparticles via glutaraldehyde coupling reaction. Finally, TF3 was effectively synthesized by applying the immobilized PPO as biocatalyst with epicatechin gallate (ECG) and epigallocatechin-3-O-gallate (EGCG) as substrates, and the maximum yield of TF3 was 42.23% based on the amount of ECG added. In addition, the immobilized enzyme still remained 85% of its initial ability after successive usage of 8 cycles and could be stored for 30days with less loss of activity. All the results suggest that the developed procedure is quite useful and has great potential for synthesis of TF3 and other theaflavins.
authors: College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China; College of Biological and Food Engineering, Huaihua University, Huaihua 418008, Hunan, China.
authors: Shicheng
authors: S
authors: Lei
authors: College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China.
authors: Minhao
authors: M
authors: Xie
authors: College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China.
authors: Bing
authors: B
authors: Hu
authors: College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China.
authors: Li
authors: L
authors: Zhou
authors: College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China.
authors: Yi
authors: Y
authors: Sun
authors: College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China.
authors: Muhammad
authors: M
authors: Saeeduddin
authors: Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100093, China.
authors: Hongcheng
authors: H
authors: Zhang
authors: College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China. Electronic address: zengxx@njau.edu.cn.
authors: Xiaoxiong
authors: X
authors: Zeng
mesh_terms: D044946:Biflavonoids / Q000138:chemical synthesis*; D055162:Biocatalysis; D002392:Catechin / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D004156:Catechol Oxidase / Q000737:chemistry* / Q000302:isolation & purification; D003432:Cross-Linking Reagents / Q000737:chemistry; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000302:isolation & purification; D017743:Equipment Reuse; D052203:Ferrosoferric Oxide / Q000737:chemistry; D005976:Glutaral / Q000737:chemistry; D007700:Kinetics; D053768:Metal Nanoparticles / Q000737:chemistry; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification; D055503:Protein Multimerization; D031989:Pyrus / Q000737:chemistry / Q000201:enzymology; D013379:Substrate Specificity
chemical_list: D044946:Biflavonoids; D003432:Cross-Linking Reagents; D004800:Enzymes, Immobilized; D010940:Plant Proteins; C585473:theaflavin-3,3'-digallate; D002392:Catechin; C062669:epicatechin gallate; C045651:epigallocatechin gallate; D004156:Catechol Oxidase; D005976:Glutaral; D052203:Ferrosoferric Oxide
keywords: Fe(3)O(4)/chitosan nanoparticles; Huangguan pear; Immobilization; Polyphenol oxidase; Synthesis; Theaflavin-3,3′-digallate