@article{oai:nagasaki-u.repo.nii.ac.jp:00004642,
 author = {Kusano, Rie and Matsuo, Yosuke and Saito, Yoshinori and Tanaka, Takashi},
 issue = {36},
 journal = {Tetrahedron Letters},
 month = {Sep},
 note = {A large number of black tea polyphenols remain uncharacterized because of the complexity of catechin oxidation reactions that occur during tea fermentation. In the course of our studies on black tea polyphenols, we examined the enzymatic degradation of theaflavins, which are black tea pigments having a benzotropolone chromophore. Oxidation of theaflavin with peroxidase afforded a new product named theacoumarin A together with known pigment theanaphthoquinone. The structure of the new compound was determined by spectroscopic examination and a production mechanism via theanaphthoquinone is proposed., Tetrahedron Letters, 56(36), pp.5099-5102; 2015},
 pages = {5099--5102},
 title = {Oxidation mechanism of black tea pigment theaflavin by peroxidase},
 volume = {56},
 year = {2015}
}