Dr Daniel Dias
||School of Botany,
Building 123, Room G24
|Phone||+61 3 8344 3318|
University Research Themes
- Natural Products Chemistry
- Analytical Wine Chemistry
- Molecular characterization and spectroscopy
- Biological and medicinal chemistry
Natural products (NPs) have been the mainstay of disease therapy for most of human history and are a major source of modern pharmaceuticals, predominantly from plant origin and recently from marine sources. Following the discovery of penicillin, many other drug breakthroughs from microbial sources occurred and with the advances in diving techniques (improved SCUBA technologies) in the 1970s subsequently opened the seas as a new source for NPs. Chemical synthesis, shifted the focus of drug discovery efforts from nature to the laboratory bench in the late 1980s. Of the 1135 new drugs approved from 1981-2010, 50% are of natural product origin (and their derivatives/analogs). A drug discovery program endeavours to search for novel bioactive NPs, nevertheless, the isolation of known, abundant NPs with no chemical or pharmacological interest is inevitable.
Dr Dias’ PhD research led to the isolation and structure elucidation of 34 known and 10 novel bioactive natural products (secondary metabolites) from selected terrestrial (fungi, lichens and plants) and marine organisms (marine red algae and sponges). Isolated NPs were evaluated for biological activities against selected anti-microbial, anti-viral and anti-tumoral lines.
All natural product extracts were subjected to the following methodologies and workflow:
- Fractionation and semi-purification of extracts using solvent extraction, solvent partitioning and bench column chromatography
- Purification and isolation of NPs carried out using semi-preparative HPLC
- Structure elucidation was carried out by 1D (1H and 13C NMR) and 2D NMR spectroscopy (COSY, HSQCAD and HMBC) and mass spectrometry (ESI-MS and EI-MS)
- Secondary techniques include - Ultraviolet Absorption Spectroscopy, Fourier Transform-Infrared Spectroscopy and optical rotation.
- Stereochemical assignments and elucidation: 1D Selective NOE NMR experiments or by single crystal X-ray analysis.
Isolated natural products were then evaluated for biological activity and a conclusion made regarding whether the natural product was solely or partly responsible for the biological activity displayed in the crude extract. Novel techniques such HPLC-NMR was also used to profile (dereplicate) natural product extracts and investigate NPs sensitive to light and oxidation (see published journal articles below).
PhD Thesis available at: http://researchbank.rmit.edu.au/view/rmit:9520
Dr Dias was offered a post-doctoral position at the School of Chemistry, The University of Melbourne. This one-year research project entitled “The oxidative spoilage of wine and effect of bottle colour” was funded by the Grape and Wine Research and Development Corporation (GWRDC). Dr Dias’ research examined the influence of light (visible and ultraviolet), temperature, glass transmission (colour and bottle thickness) on the development of pigmentation in white wine. The key findings of this project were the identification of the critical wavelengths of light that led to pigment production, separation of light and thermal effects on pigment production, the identification of iron(III) tartrate as the photoactive species responsible for the photo-activation and the relationship between bottle colour and weight on light and thermal induced changes.
Report Available at: http://www.gwrdc.com.au/wp-content/uploads/2012/09/UM-09021.pdf
In August 2010, Dr Dias was appointed as the leader of GC-MS services at Metabolomics Australia, the School of Botany node. Metabolomics Australia (MA) is an Australian Federal Government co-investment (National Collaborative Research Infrastructure Strategy 5.1 Evolving Biomolecular Platforms) through Bioplatforms Australia Ltd and EIF SuperScience which provides “state-of-the-art” metabolomics as a “fee-for-service” including analytical and computational capabilities to national and international researchers, located in universities, government research organizations and industry.
Dr Dias has recently been awarded The University of Melbourne, Early Career Research Grant (2014) presenting him the opportunity to combine both natural products chemistry with metabolomics at the University. His research will streamline the challenges involved in isolating novel bioactive natural products from Australian terrestrial and marine organisms. By combining metabolomics(the comprehensive study of small molecules) with natural products chemistry in conjunction with the latest advances in analytical technologies comprising of chromatography, mass spectrometry, nuclear magnetic resonance (NMR) and structural prediction software will potentially identify bioactive NPs from selected marine algae in an efficient manner.
- Metabolomics Australia: www.metabolomics.net.au
- The Australian and New Zealand Metabolomics Network: www.anzmn.com.au
- Roessner U and Dias DA (2013). Plant tissue extraction for metabolomics. In Roessner, U. and Dias, DA. (Editors) Methods in Molecular Biology, Metabolomics Tools for Natural Product Discoveries, Humana Press, New York, USA, pp 21-28.
- Jayasinghe NS and Dias DA. (2013). A robust method for the quantitation of fatty acids in biological systems. In Roessner, U. and Dias, DA. (Editors) Methods in Molecular Biology, Metabolomics Tools for Natural Product Discoveries, Humana Press, New York, USA. pp 39-56.
- Urban S and Dias DA (2013). NMR Spectroscopy: Structure Elucidation of Cycloelatane A: A Natural Product Case Study. In Roessner, U. and Dias, DA. (Editors) Methods in Molecular Biology, Metabolomics Tools for Natural Product Discoveries, Humana Press, New York, USA. pp 99-116.
- Jones OAH, Maguire ML, Griffin JL, Dias DA, Spurgeon DJ, Svendsen C, Metabolomics and Its Use in Ecology. (2013). Austral Ecology. 38: 713-720.
- Olmstead ILD, Hill DRA, Dias DA, Jayasinghe NS, Callahan DL, Kentish SE, Scales PJ, Martin GJO. (2013) A quantitative analysis of microalgal lipids for optimization of biodiesel and omega-3 production. Biotechnology and Bioengineering. 110: 2096-2104.
- Dias DA, Clark AC, Smith TA, Ghiggino KP and Scollary GR. (2013) Wine bottle colour and oxidative spoilage: whole bottle light exposure experiments under controlled and uncontrolled temperature conditions. Food Chemistry 138: 2451-2459
- De Livera AM, Dias DA, De Souza D, Rupasinghe T, Pyke, J, Tull D, McConville M, Roessner, U and Speed TP. (2012) Normalising and integrating metabolomics data. Analytical Chemistry, 84: 10768-10776.
- Dias DA, Urban S and Roessner U. (2012) A Historical Overview of Natural Products in Drug Discovery. Metabolites, 2: 303-336.
- Dias DA, and Urban S. (2011) Phytochemical Studies of the Southern Australian marine alga, Laurencia elata. Phytochemistry, 72: 2081-2089.
- Dias DA and Urban, S. (2009) Chemical Constituents of the Lichen, Candelaria concolor: A Complete NMR and Chemical Degradative Investigation. Natural Product Research, 23: 925-939.
- Dias DA, White J and Urban, S. (2009) Laurencia filiformis: Phytochemical Profiling by Conventional and HPLC-NMR Approaches. Natural Product Communications 4: 157-172.
- Dias DA, Goble DJ, Silva CA and Urban S. (2009) Phenylphenalenones from the Australian Plant, Haemodorum simplex. Journal of Natural Products 72: 1075-1080.