The
genus <i>Rhodocodon</i> (Hyacinthaceae sensu APG II) is
endemic to Madagascar, and its phytochemistry has not been described
previously. The phytochemistry of three species in this genus has
been investigated, and eight compounds, including three bufadienolides
(compounds <b>1</b>, <b>4</b>, and <b>5</b>), a
norlignan (<b>2</b>), and four homoisoflavonoids (compounds <b>3</b> and <b>6</b>–<b>8</b>), have been isolated
and identified. Compounds <b>1</b>–<b>3</b> and <b>6</b>–<b>8</b> have not been described previously.
The COX-2 inhibitory activity of compound <b>6</b> and compound <b>7</b> acetate (compound <b>7A</b>) was investigated on isolated
colorectal cancer cells. Compounds <b>6</b> and <b>7A</b> inhibited COX-2 by 10% and 8%, respectively, at a concentration
of 12.5 μM compared to 12% for 1 mM aspirin (the positive control)
