American Chemical Society
np2c01037_si_001.pdf (2.62 MB)

seco-Pregnane Glycosides from Australian Caustic Vine (Cynanchum viminale subsp. australe)

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journal contribution
posted on 2023-02-16, 20:06 authored by Yongbo 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 58 are not associated with the reported toxicity of this plant species.