Trichilianones A-D, Novel Cyclopropane-Type Limonoids from Trichilia adolfi

Abstract

The fractionation of an ethanol extract of the bark of <i>Trichilia adolfi</i> yielded four novel limonoids (trichilinones A-D, <b>1</b>-<b>4</b>), with five fused rings and related to the hortiolide-type limonoids. Starting with an ε-lactone, which is α,β-unsaturated in trichilinones A and D (<b>1</b> and <b>4</b>), attached to a tetrahydrofuran ring that is connected to an unusual bicyclo [5.1.0] hexane system, joined with a cyclopentanone with a 3-furanyl substituent [(2-oxo)-furan-(5<i>H</i>)-3-yl in trichilinone D (<b>4</b>)], the four compounds isolated display a new 7/5/3/5/5 limonoid ring system. Their structures were established based on extensive analysis of NMR spectroscopic data. As the crude extract possessed anti-leishmanial properties, the compounds were assayed for cytotoxic and anti-parasitic activities in vitro in murine macrophages cells (Raw 264.7) and leishmania promastigotes (<i>L. amazoniensis</i> and <i>L. braziliensis</i>), respectively. The compounds showed moderate cytotoxicity (approximately 70 μg/mL), but are not responsible for the leishmanicidal effect of the extract.