Naio (Myoporum sandwicense) is a small tree or shrub that is native to Hawaii. Early Hawaiians used Naio for building materials in their homes. The heartwood has a similar smell to sandalwood, and used to be passed off as true ‘iliahi, although the deception did not fool many importers, giving rise to the nickname “false sandalwood.”
Naio has a high alpha-bisabolol content, which is one of the most in-depthly studied compounds due to its many health benefits. In an APRC publication, two samples of M. sandwicense wood were steam-distilled in a lab setting and analyzed by GC-MS. The average oil yield was 0.34%. The oil was yellow to golden in color and had a woody, sweet, slightly spicy, and sandalwood-like aroma. Twenty-three industrially produced M. sandwicense wood oils were analyzed by GC-MS. Both lab-distilled and industrially distilled M. sandwicense wood essential oils were dominated by alpha-bisabolol and trans-alpha-bisabolol oxide B.
These essential oils were screened for antimicrobial activity against a panel of potentially pathogenic bacteria and fungi. The leaf essential oil of M. sandwicense showed excellent antibacterial activity against S. pyogenes and antifungal activity against A. fumigatus. The wood essential oil of M. sandwicense, which was dominated by alpha-bisabolol and alpha-bisabolol oxide B, also showed notable activity against S. pyogenes, A. fumigatus, A. niger, and M. gypseum. alpha-Bisabolol has shown marginal antibacterial activity, but good antifungal activity. In addition, alpha-bisabolol has been shown to potentiate the antibacterial activities of several antibiotics.