Antimalarial ceramicines Q-T from Chisocheton ceramicus

Area of Science:

• Natural Product Chemistry
• Medicinal Chemistry
• Pharmacology

Background:

• Ceramicines are known limonoids with diverse biological activities.
• These compounds are derived from the Malaysian plant Chisocheton ceramicus.
• Previous studies have indicated various bioactivities of ceramicines.

Purpose of the Study:

• To isolate and characterize new limonoids from Chisocheton ceramicus.
• To investigate the structural features of these novel compounds.
• To evaluate the biological activity, specifically antimalarial potential, of the isolated limonoids.

Main Methods:

• Isolation of compounds from C. ceramicus bark.
• Structure elucidation using 1D and 2D Nuclear Magnetic Resonance (NMR) analyses.
• Comparison with calculated ¹³C chemical shift data for structural confirmation.

Main Results:

• Four new limonoids, ceramicines Q-T (1-4), were successfully isolated.
• Structures were determined, revealing a unique cyclopentanone[α]phenanthren ring system with a β-furyl ring at C-17.
• Notably, these new compounds lack the tetrahydrofuran ring present in known ceramicines.
• Ceramicine R (2) exhibited potent antimalarial activity against Plasmodium falciparum 3D7 with an IC₅₀ of 2.8 µM.

Conclusions:

• Ceramicines Q-T represent a novel series of limonoids with distinct structural characteristics.
• The findings expand the chemical diversity of ceramicines.
• Ceramicine R shows promising antimalarial potential, warranting further investigation.