Triterpene glycosides from transformed root cultures of Astragalus mongholicus BGE

Abstract

Transfonned root cultures of Astragalus mongholicus Bge. have been established by infecting of sterile grown plants with AgrobacterilDfl rhizogenes strains LBA 9402 and ATCC 15834. A promoting effect of acetyl syringone on the Agrobacteriwn-mediated hairy root (HR) initiation was obselVed. The transfonned root clones were assayed for opines by electrophoresis and 1LC. All of them were positive for agropine/mannopine. It was shown, that Astragalus-hairy roots (HR) of the transfonned cultures produce the same kind of saponins in considerable amounts as those of intact plants. The triterpene saponins have been isolated from the methanol extract of the HR and identified as cycloartane derived saponins. On the basis of analytical data obtained by mass spectrometry (NI-F AB-MS, EI-MS), and homo- and heteronuclear NMR experiments (DEPT, DQF-COSY, HOHAHA, ROESY, HMQC, HMBC), the structures of three triterpenoid glycosides were determined as astragaloside I, IT, ill [1,2]. A complete assignment of the IH_ and 13C-NMR data is given.