Cyclobutane dimers from the Colombian medicinal plant Achyrocline bogotensis.

Five cyclobutane dimers, achyrodimers A-E (1-5), along with 11 known compounds were isolated from the methanol extract of the Colombian medicinal plant Achyrocline bogotensis. Their structures were elucidated by spectroscopy. Several of these compounds were screened for cytokine-inducing activity in human peripheral blood mononuclear cells.