Cytotoxic triterpenoid alkaloids from Buxus microphylla

Area of Science:

• Natural Product Chemistry
• Medicinal Chemistry
• Pharmacology

Background:

• Buxus microphylla is a plant species known to produce various bioactive compounds.
• Triterpenoid alkaloids represent a class of natural products with diverse pharmacological activities.

Purpose of the Study:

• To isolate and characterize new triterpenoid alkaloids from Buxus microphylla.
• To evaluate the cytotoxic potential of isolated compounds against cancer cell lines.

Main Methods:

• Isolation of compounds using chromatographic techniques.
• Structure elucidation through Nuclear Magnetic Resonance (NMR) and Mass Spectrometry (MS).
• Determination of relative stereochemistry via single-crystal X-ray crystallography.
• Cytotoxicity assays using HepG2 and K562 cell lines.

Main Results:

• Five new triterpenoid alkaloids, buxmicrophyllines E-I (1-5), were identified alongside six known compounds (6-11).
• The structures of compounds 1-5 were fully characterized.
• Compound 3 exhibited potent cytotoxicity against HepG2 cells (IC50 = 0.89 μM), and compound 9 showed similar activity (IC50 = 0.78 μM).
• Compounds 2, 3, 7, 8, and 9 demonstrated cytotoxicity against K562 cells, with IC50 values ranging from 0.37 to 4.44 μM.

Conclusions:

• Buxus microphylla is a rich source of novel triterpenoid alkaloids.
• Several isolated compounds, particularly buxmicrophyllines, possess significant cytotoxic activity against human cancer cell lines, warranting further investigation for therapeutic potential.