Rana A.,Hill Area Tea Science Division |
Kumar D.,CSIR - Central Electrochemical Research Institute |
Joshi R.,Hill Area Tea Science Division |
Gulati A.,Hill Area Tea Science Division |
Singh H.P.,Hill Area Tea Science Division
Chemistry of Natural Compounds | Year: 2015
The present study reports the comparative in vitro cytotoxicity of theaflavin digallate (2) and isotheaflavin digallate (1), a new black tea theaflavin against Chinese hamster ovary cells (CHOK1) and rat glioma cells (C-6). Compound 1 was formed by the immobilized polyphenol oxidase (PPO) mediated enzymatic oxidation of (-) GCG and (-) ECG along with compound 2, which was formed by enzymatic oxidation of (-) EGCG and (-) ECG. The structures of the compounds were elucidated using ESI-Q-TOF-MS and 1D and 2D NMR. The results of a comparative cytotoxicity assay have revealed that isotheaflavin digallate is more cytotoxic than theaflavin digallate (IC50 246.8 μg/mL against CHOK1, IC50 288.8 μg/mL against C-6 cells). © 2015 Springer Science+Business Media New York.