Isolation and biological activity of a novel cadinane-type sesquiterpenoid from the essential oil of Alangium salviifolium.

The components of the essential oil from the roots of Alangium salviifolium were analyzed by capillary gas chromatography-mass spectrometry (GC-MS). Ninety compounds, representing 74.5% of the total oil, were identified; the main components of the oil were epi-α-cadinol, followed by trans-2-hydroxycalamenene, cadalene, and cadina-4,10(15)-dien-3-one. A further unknown component comprised 5.5% of the oil. Therefore, the essential oil was purified by flash column chromatography to isolate this component. Its structure was established using extensive spectroscopic data analyses, including NMR, HR-EI-MS, and IR. The results showed that this isolated compound was (-)-7, 8-dihydroxycalamenal, which is a novel cadinane-type sesquiterpenoid. This compound was tested for its antioxidant activity and inhibition of tyrosinase, and showed particularly strong inhibition effects.