Three plant growth inhibiting saponins from Duranta repens

Three new triterpenoid-type saponins were isolated from leaves of Duranta r epens using plant growth inhibiting activity against seedlings of Brassica juncea var. cernua as a guide for fractionation. The structures of these co mpounds were elucidated as polygalacic acid-3-O-beta-D-glucopyranosido-28-O -[alpha-L-rhamnopyranosyl-(1-->3')-beta-D-apiofuranosyl-(1--->4)-alpha-L-rh amnopyranosyl-(1 -->2)-beta-L-arabinopyranoside] (durantanin I), polygalaci c acid-3-O-beta-D-glucopyranosido-28-O-[alpha-L-rhamnopyranosyl-(1-->3)-bet a-D-xylopyranosyl-(1 --> 4)-[beta-D-apiofuranosyl-(1 --> 3)]-alpha-L-rhamno pyranosyl-(1 --> 2)-beta-L-arabinopyranoside] (durantanin II), and polygala cic acid-3-O-beta-D-glucopyranosido-28-O-[alpha-L-rhamnopyranosyl-(1 --> 3) -beta-D-xylopyranosyl-(1 --> 4)-alpha-L-rhamnopyranosyl-(1 --> 2)-beta-L-ar abinopyranoside] (durantanin III). (C) 1999 Elsevier Science Ltd. All right s reserved.