Y Mimaki, O Nakamura, Y Sashida, K Koike, T Nikaido, T Ohmoto, A Nishino, Y Satomi, H Nishino
Phytochemical examination of the fresh tubers of Brodiaea californica resulted in the isolation of four new steroidal saponins. Their structures were determined, by extensive spectral analysis including two-dimensional (2D) NMR spectroscopy and acid-catalyzed hydrolysis, to be (25S)-spirost-5-ene-1 beta,3 beta-diol [(25S)-ryscogenin] 1-O-[O-beta-D-glucopyranosyl-(1-->3)-O-alpha-L-rhamnopyranosyl-(1-->2)- beta-D-glucopyranoside] (1), (25S)-ruscogenin 1-O-[O-beta-D-glucopyranosyl-(1-->3)-O-alpha-L-rhamnopyranosyl-(1-->2)-O -[beta-D-xylopyranosyl-(1-->3)]-beta-D-glucopyranoside] (2), the C-20 and C-22 isomer of 2 (3) and the 6'-O-acetyl derivative of 2 (4), respectively...
June 1995: Chemical & Pharmaceutical Bulletin