Targeted Chemical Profiling and Dereplication of Australian Plants of the Family Haemodoraceae Using a Combined...

Australian plants of the family Haemodoraceae have been a reliable source of new secondary metabolites, particularly those of the 'phenylphenalenone' class, and related chromenes and xanthones. Some of these compounds demonstrate anti-microbial properties against both Gram-negative and Gram-positive bacteria. Chemical profiling of thirty individual ethanolic extracts from six separate species of Australian plants belonging to the family Haemodoraceae was conducted using an HPLC-MS approach reinforced by HRLC(ESI)-MS. Six of the extracts were further explored by employing HRLC(ESI)-MS and the compounds present were characterised and confirmed based on a comparison to the original data. All thirty extracts were assessed for biological activity against the parasitic nematode Haemonchus contortus in vitro. The chemical profiling methodology adopted resulted in the identification of thirty-four previously reported compounds, identifying on average 64% of the previously reported secondary metabolites across the species Haemodorum simulans, Haemodorum spicatum, Haemodorum brevisepalum and Macropidia fuliginosa. Furthermore, compounds from the phenylbenzoisoquinolindone class were detected in the bulbs of Haemodorum simulans and Haemodorum coccineum, representing the first report of the structure class in extracts of the genus Haemodorum. Extracts of the H. simulans stems, M. fuliginosa bulbs and H. distichophyllum roots and bulbs exhibited anthelmintic activity in vitro. The chemical profiling HPLC-MS methodology adopted was successful in the rapid identification of most of the previously reported secondary metabolites across the Haemodoracae species, indicating that the analytical approach was robust. This study demonstrates the effectiveness of dereplication via HPLC-MS-based chemical profiling across six Australian Haemodoraceae species, identifying numerous known and putatively novel secondary metabolites. It also reports, for the first time, anthelmintic activity in selected species and marks the first detailed phytochemical investigation of H. distichophyllum since its initial pigment analysis over 50 years ago.