title: High-molecular-weight polyphenols from oolong tea and black tea: purification, some properties, and role in increasing mitochondrial membrane potential.
abstract: High-molecular-weight polyphenols from oolong and black teas increased mitochondrial membrane potential, as measured by a method using ciliated protozoan Tetrahymena and rhodamine 123. These polyphenols, referred to as mitochondrial activation factors (MAFs), were purified from oolong and black teas by solvent extraction and Toyopearl column chromatography. The number-average molecular weights of the MAFs were 9,000 to 18,000, and the weight-average molecular weights were 15,000 to 25,000. The MAFs increased the mitochondrial membrane potential more than catechins did. Treatment of the MAFs with tannase indicated that they contained galloyl residues. When the MAFs were hydrolyzed with HCl-n-BuOH, cyanidin and delphinidin were detected. The partial structure of the MAFs was analyzed by pyrolysis-gas chromatography-mass spectrometry, and nine compounds were identified. These results suggest that MAFs are heterogeneous polymers of flavan-3-ols and flavan-3-ol gallates with intermonomeric linkages of B-ring to B-ring and C-ring to A-ring.
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Fujihara
authors.forename: Akiko
authors.initials: A
authors.lastname: Nakagawa-Izumi
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ozawa
authors.forename: Osamu
authors.initials: O
authors.lastname: Numata
mesh_terms: D000818:Animals; D000872:Anthocyanins / Q000737:chemistry; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism; D002392:Catechin / Q000494:pharmacology; D002845:Chromatography; D005419:Flavonoids / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects* / Q000502:physiology; D010636:Phenols / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D059808:Polyphenols; D020112:Rhodamine 123 / Q000737:chemistry; D013662:Tea / Q000737:chemistry*; D013769:Tetrahymena pyriformis / Q000187:drug effects* / Q000502:physiology
chemical_list: D000872:Anthocyanins; D005419:Flavonoids; D005456:Fluorescent Dyes; D010636:Phenols; D010936:Plant Extracts; D059808:Polyphenols; D013662:Tea; D020112:Rhodamine 123; C404987:flavan-3-ol; C017154:cyanidin; D002392:Catechin; D002265:Carboxylic Ester Hydrolases; C022711:tannase; C017185:delphinidin