Antiplasmodial Oleanane Triterpenoids from Terminalia albida Root Bark.

Area of Science:

• Natural Product Chemistry
• Medicinal Chemistry
• Pharmacognosy

Background:

• The roots of Terminalia albida (Combretaceae) are a potential source of bioactive compounds.
• Phytochemical investigations are crucial for identifying novel therapeutic agents.

Purpose of the Study:

• To isolate and characterize oleanane triterpenoids from the n-BuOH extract of Terminalia albida roots.
• To evaluate the antiplasmodial and antimicrobial activities of the isolated compounds.

Main Methods:

• Isolation and purification of compounds using chromatographic techniques.
• Structure elucidation using 1D and 2D NMR spectroscopy and ESI mass spectrometry.
• Biological activity screening against Plasmodium falciparum, Candida albicans, and Staphylococcus aureus.

Main Results:

• Ten oleanane triterpenoids were isolated, including six new compounds (albidanoside A, albidic acid A, albidinolic acid, albidienic acid, albidolic acid, albidiolic acid) and two new aglycones (albidic acid B, albidic acid C).
• Compounds 1-4, 6, 7, and 8 exhibited moderate antiplasmodial activity with IC50 values ranging from 5 to 15 μM against Plasmodium falciparum K1.
• No significant antimicrobial activity was observed against Candida albicans or Staphylococcus aureus.

Conclusions:

• Terminalia albida roots are a rich source of diverse oleanane triterpenoids.
• The identified compounds, particularly those showing antiplasmodial activity, highlight the potential of Terminalia albida in the discovery of new antimalarial drugs.
• Further research into the structure-activity relationships of these triterpenoids is warranted.