Trichilones A-E: New Limonoids from Trichilia adolfi

Area of Science:

• Natural Product Chemistry
• Medicinal Plant Research
• Organic Chemistry

Background:

• The bark of *Trichilia adolfi* is a known source of bioactive compounds.
• Previous research identified trichilianones A-D from this plant.
• The crude ethanol extract of *T. adolfi* bark exhibits antileishmanial activity.

Purpose of the Study:

• To isolate and characterize new limonoids from *Trichilia adolfi*.
• To investigate the cytotoxic and antiparasitic potential of these novel compounds.
• To determine if the isolated limonoids contribute to the extract's antileishmanial activity.

Main Methods:

• Isolation of chemical constituents using ethanol extraction.
• Structure elucidation of new metabolites via high-field NMR spectroscopy and HR mass spectrometry.
• In vitro assays for cytotoxic activity in murine macrophage cells (raw 264.7) and antiparasitic activity against *Leishmania amazoniensis* and *L. braziliensis* promastigotes.

Main Results:

• Five new prieurianin-type limonoids (compounds 1-5) were isolated and characterized.
• Compounds 1-5 feature a characteristic four-fused ring system with an ε-lactone, unsaturated in compounds 4 and 5.
• Metabolites 1-3 and 5 demonstrated moderate cytotoxicity (30-94 µg/mL) but did not account for the extract's antileishmanial effect.

Conclusions:

• The chemical investigation of *Trichilia adolfi* yielded five novel limonoids.
• The isolated limonoids exhibit moderate cytotoxicity but are not the primary drivers of the antileishmanial activity observed in the crude extract.
• Further research may be needed to identify the specific compounds responsible for the antileishmanial properties of *T. adolfi*.