Discovering anti-fungal agents in New Zealand native plants for use in wood protection
IRG/WP 09-10692
C Rickard, T Singh, A Singh, R Newman
Extracts from Hinau (Elaeocarpus dentatus) leaves were tested in the laboratory for antifungal activity. In addition, the anatomical structure of the leaf was also examined by a combination of light and scanning electron microscopy. Chemical characterisation of the extracts and investigation into potential use of its components for wood protection is underway. A combination of light microscopy (LM) and scanning electron microscopy (SEM) proved most effective for examining the tissue composition, particularly in differentiating the distribution of lignified tissues relative to non-lignified tissues after staining freshly cut leaf sections with phloroglucinol-HCl stain, which specifically stains lignin in cell walls. In-vitro bioassay results showed antifungal activity of Hinau extracts against two brown rot fungi, Oligoporus placenta and Coniophora puteana. NMR spectra of the Hinau extracts indicated mixtures of aromatic substances, showing chemical shifts consistent with ellagitannins and/or gallotannins with minor contributions consistent with flavonoids. The identity of the bioactive component remains unknown.