Steroidal saponins from the rhizomes of Polygonatum sibiricum

Investigation of the rhizomes of Polygonatum sibiricum led to the isolation of the previously reported neoprazerigenin A 3-O-beta-lycotetraoside [3], its methyl proto-type congener 2, and two new steroidal saponins, sibiricosides A [1] and B [4]. The structures have been determined by spectral means and by comparison with literature data and authentic samples.