Tea triterpenoidal saponins from the roots of Camellia sinensis have inhibitory effects against alcohol dehydrogenase.

Ten new polyhydroxyolean-12-ene pentacyclic triterpenoidal saponins, named rogchaponins 1-10, were isolated from the methanolic extract of the roots of Camellia sinensis by a series of chromatographic methods (silica gel flash column and C18 MPLC followed by C18 HPLC). Their structures were established by 1D and 2D-NMR techniques along with IR and HR-TOF-MS. Rogchaponins R4 (4) and R5 (5) showed inhibitory activities against yeast alcohol dehydrogenase (ADH) with IC50 values of 16.1 +/- 3.2 and 15.4 +/- 3.3 mu M, respectively. A 4-methylpyrazole positive control exhibited an IC50 of 2750 +/- 50 mu M. However, the saponins showed no inhibitory activity against yeast aldehyde dehydrogenase (ALDH).