JOURNAL 266


Records of Natural Products
VOLUME & ISSUE
Year: 2017 Issue: 4 July-August
PAGES
p.344 - 344
STATISTICS
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AUTHORS
    Eric Wei Chiang Chan, Nuha I. Sweidan, Siu Kuin Wong and Hung Tuck Chan
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GRAPHICAL ABSTRACT


ABSTRACT


From different plant parts of Calotropis species (C. gigantea and C. procera), various classes of compounds such as oxy pregnanes, terpenoids, sterols, cardenolides and flavonoids have been isolated. Of these compounds, the cardenolides stand out as many of them have anticancer properties. Cardenolides are C 23 steroids with a five-membered unsaturated butyrolactone ring consisting of a steroid nucleus, a lactone moiety at C-17 and a sugar moiety at C-3. The roles of cardenolides in the treatment of human cancer have been established as they can induce apoptosis and inhibit the growth of cancer cells. Structure‒activity relationship analyses have yielded some interesting findings on their cytotoxicity. Compounds with six-membered ring sugar groups generally have significantly stronger inhibitory activity than those with five-membered ring sugar groups. A formyl or methyl-hydroxyl group at C-10 enhances cytotoxicity while the presence of a 4´-OH or 16-OH group decreases cytotoxicity. Chemical modification of 2”-oxovoruscharin, a novel cardenolide extracted from the root bark of C. procera, has led to the synthesis of UNBS1450. The compound is characterized by more potent anti-proliferative activity, lower toxicity, and is a strong sodium pump inhibitor and inducer of non-apoptotic cell death. UNBS1450 is currently in Phase I clinical trials.

KEYWORDS
  • Calotropis gigantea
  • Calotropis procera
  • cytotoxicity
  • structure - activity relationship.