Outer-surface adduct formation and selective separation of -type gallated and -type non-gallated catechins using cucurbit[7]uril.

We found that -type gallated and non-gallated catechins form low water solubility outer-surface adducts with cucurbit[7]uril in aqueous solution, with -type gallated catechins showing a higher tendency to precipitate as outer-surface adducts. By exploiting this phenomenon, we achieved the selective separation of -type gallated and non-gallated catechins in solution.