Triterpenoid saponins from the roots of tea plant (Camellia sinensis var. assamica)

Three olean-12-ene type triterpenoid saponins, named TR-saponins A, B and C , were isolated as methyl esters from tea roots (Camellia sinensis var. ass amica) after treatment with diazomethane. Their structures were established as the methyl eaters of 3-O-alpha-L-arabinopyranosyl (1 --> 3)-beta-D-gluc uronopyranosyl-21, 22-di-O-angeloyl-R-1-barrigenol-23-oic acid, 3-O-alpha-L -arabinopyranosyl (1 --> 3)-beta-D-glucuronopyranosyl-21-O-angeloyl-22-O-2- methylbutanoyl-R-1-barrigenol-23-oic acid and 3-O-alpha-L-arabinopyranosyl (1 --> 3)-beta-D-glucuronopyranosyl-16 alpha-O-acetyl-21-O-angeloyl-22-O-2- methylbutanyol-R-1-barrigenol-23-oic acid,(2) by extensive 1D and 2D-NMR as well as FABMS and HR-MS analyses. (C) 2000 Elsevier Science Ltd. All right s reserved.