Antineoplastic agents. 534. isolation and structure of sansevistatins 1 and 2 from the African Sansevieria ehrenbergii.

Using bioactivity-directed isolation procedures, three new spirostanol saponins designated sansevierin A (1), sansevistatin 1 (2), and sansevistatin 2 (3) were isolated (10-5 % yield) from the CH3OH−CH2Cl2 extract of Sansevieria ehrenbergii, accompanied by three known steroidal saponins (4−6). The structures were determined on the basis of chemical methods and spectroscopic analysis, especially 1D and 2D NMR experiments. Each of the saponins was evaluated against the P388 lymphocytic leukemia cell line and a panel of human cancer cell lines. Except for 1, all were found to cause inhibition of cancer cell growth. In addition, most of the saponins exhibited antimicrobial activity, particularly against the pathogenic fungi Candida albicans and Cryptococcus neoformans.