Phytochemical variability of 'Pittosporum angustifolium' Lodd. (Pittosporaceae): a traditional and contemporary Aboriginal Australian medicine

Abstract

The traditional Aboriginal medicinal plant 'Pittosporum angustifolium' has recently achieved certain notoriety in the wider 'underground' complementary therapy market. The distribution and quality of this plant material is currently unregulated and few studies have examined phytochemical variability of this species. If repeatable empirical outcomes, as opposed to anecdotal reports, can be expected such studies may be a necessary undertaking. In the current study a preliminary phytochemical analysis was undertaken to find evidence of relative geographical variability. Firstly, lipid was extracted from both leaves and twigs, then the free fatty acid fraction was esterified and examined using GC-MS. Secondly, methanol extracts of leaves and twigs, using specimens of various provenances in New South Wales and Queensland, were subject to HPLC-DAD analysis to examine the variability in the elution profile of UV absorbing components. GC-MS results demonstrated a difference in the free fatty acid profile between leaves and twigs whereas HPLC demonstrated some evidence of geographical variability of the more polar components.