Revision of the Absolute Configurations of Bethosides B and C and Their Aglycone
作者:Victoria L. Challinor、Patricia Y. Hayes、Paul V. Bernhardt、William Kitching、Reginald P. Lehmann、James J. De Voss
DOI:10.1021/jo2012797
日期:2011.9.2
The absolute stereochemistry of the steroidal saponins bethosides B and C was previously assigned as (22R,25R) on the basis of work that employed Horeau’s method. Our studies of helosides A and B created doubt about both the original assignment and consequently our conclusion that relied upon it. The absoluteconfigurations of bethosides B and C are revised to (22S,25R) following X-ray crystallographic
Six new cholestane glycosides (1, 5, 6, 10, 12, and 13) and two new sterols (9 and 11), along with five known compounds (2–4, 7, and 8), were isolated from the underground parts of Chamaelirium luteum (Liliaceae). The structures of these new compounds were determined by spectroscopic analysis and the results of hydrolytic cleavage. The isolated compounds and aglycones were evaluated for their cytotoxic activity against HL-60 human leukemia cells. Compounds 6a, 10a, 12a, 13, and 13a were cytotoxic to HL-60 cells, with IC50 values of 12.8, 9.8, 15.3, 6.2, and 10.2 µM, respectively.