Chemical constituents and biological activities of Albizia myriophylla wood

Abstract

Context: Albizia myriophylla Benth (Leguminosae) is a medicinal plant widely used in Thailand and other Asian countries as a folk medicine remedy for many ailments.

Objective: The objective of this study is to investigate the chemical compositions, antibacterial activity, and cytotoxicity of A. myriophylla wood.

Materials and methods: The structure identification of the isolated compounds was established using spectroscopic methods. In vitro antibacterial activity against Streptococcus mutans, Staphylococcus aureus, and Bacillus cereus and the cytotoxicity against KB cells of extracts and compounds from A. myriophylla were performed using broth microdilution and resazurin microplate assays, respectively. The lupinifolin content in A. myriophylla extracts was quantified by high-performance liquid chromatography.

Results: A rare flavan-3,4-diol (1) together with eight known compounds (2–9) were isolated from the wood of A. myriophylla. Compounds 4–9 exhibited anti-S. mutans activity, of which lupinifolin (5) was the most potent with an MIC value of 0.98 µg/mL, followed by its dihydroxy derivative 4 with an MIC value of 62.5 µg/mL. Compounds 4 and 5 also displayed marked antibacterial activity against B. cereus and S. aureus (MIC value 15.63–125 µg/mL) and showed strong cytotoxic activity against KB cells (IC₅₀ value 4.95–12.55 µg/mL). The lupinifolin contents in ethanol extracts from two different collections of this plant originating from central and southern Thailand were 93.85 and 0.04 mg/g, respectively.

Conclusion: This is the first report of compounds 1–4 from A. myriophylla. Compounds 4 and 5 showed potent antibacterial and cytotoxic activities compared with other isolates. The anti-S. mutans activity of A. myriophylla extracts seems to be related to the lupinifolin content.

• Antibacterial activity
• cytotoxicity
• dental caries
• flavan-3
• 4-diol
• lupinifolin

Acknowledgements

The authors would like to thank Dr. Alan Frederic-Geater from the Faculty of Medicine, Prince of Songkla University, for assistance with the English.

Declaration of interest

This work was supported by a research grant for General Researcher, The Annual Income Budget of Prince of Songkla University (TTM570374S), and by TRF-CHE Research Grant for New Scholar (MRG5580107) funded by the Thailand Research fund (TRF) and the Commission on Higher Education (CHE).