posted on 2023-02-16, 20:06authored byYongbo Xue, Andrei I. Savchenko, Kylie A. Agnew-Francis, Jared A. Miles, Tina Holt, Hieng Lu, Sharon Chow, Paul I. Forster, Glen M. Boyle, Benjamin P. Ross, Katja Fischer, Andrei G. Kutateladze, Craig M. Williams
Cynanchum viminale subsp. australe, more commonly known as caustic vine, is a leafless succulent that
grows in the northern arid zone of Australia. Toxicity toward livestock
has been reported for this species, along with use in traditional
medicine and its potential anticancer activity. Disclosed herein are
novel seco-pregnane aglycones cynavimigenin A (5) and cynaviminoside A (6), together with new
pregnane glycosides cynaviminoside B (7) and cynavimigenin
B (8). Cynavimigenin B (8) contains an unprecedented
7-oxobicyclo[2.2.1]heptane moiety in the seco-pregnane
series, likely arising from a pinacol-type rearrangement. Interestingly,
these isolates displayed only limited cytotoxicity in cancer and normal
human cell lines, in addition to low activity against acetylcholinesterase
and Sarcoptes scabiei bioassays, suggesting that 5–8 are not associated with the reported
toxicity of this plant species.