Isolation and structure of a 20,21-epoxybufenolide series from "Ch'an Su"

Yoshiaki Kamano, Toshihiko Nogawa, Ayano Yamashita, Masahiko Hayashi, Masuo Inoue, Pavel Drašar, George Pettit

Research output: Contribution to journalArticlepeer-review

67 Scopus citations


Steroid bufenolides resulting from epoxidation of the 17β-2-pyrone ring of bufadienolides are rare. Five 20,21-epoxybufenolides, namely, 20S,21-epoxyresibufogenin (1), 20R,21-epoxyresibufogenin (2), 3-O-formyl-20S,21-epoxyresibufogenin (3), 3-O-formyl-20R,21-epoxyresibufogenin (4), and 3-oxo-20S,21-epoxyresibufogenin (5), were isolated from the Chinese toad skin extract drug Ch'an Su. The structures were elucidated by spectroscopic and chemical methods. The configuration at C-20 was assigned by the analysis of difference NOE spectra. The cancer cell (KB and MH-60) growth inhibition by the new 20,21-epoxybufenolides was examined, and 20,21-epoxides 1, 2, and 5 were found to significantly inhibit the leukemia MH-60 cell line.

Original languageEnglish (US)
Pages (from-to)1001-1005
Number of pages5
JournalJournal of Natural Products
Issue number7
StatePublished - 2002

ASJC Scopus subject areas

  • Analytical Chemistry
  • Molecular Medicine
  • Pharmacology
  • Pharmaceutical Science
  • Drug Discovery
  • Complementary and alternative medicine
  • Organic Chemistry


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