Education background

September 2010 - present: PhD student, University of Copenhagen, Denmark  

September 2009 – June2010: M.Sc. in “Advanced Spectroscopy in Chemistry” - II, University of Bergen, Norway

September 2008 – June 2009: M.Sc. in “Advanced Spectroscopy in Chemistry” - I, University Lille 1 – Science and Technology, France

September 2004 – June 2007: B.Sc. in “Chemistry”, Arba Minch University, Ethiopia

Research interests

A significant part of my research is focused towards development and application of the state of art HPLC-SPE-NMR for analysis of natural products of plant and fungal origin.

The rationale for this research is the following: if the compounds present in an extract or fraction can be rapidly identified without their isolation in the classical sense, and the actual isolation efforts focused on a few selected, truly novel and interesting metabolites identified in the initial phase, the efficiency of the whole process can be greatly improved. The group (NPR, Department of drug design and pharmacology) has demonstrated that the HPLC-SPE-NMR technology is compatible with all major classes of secondary metabolites from higher plants and can be used as a rapid exploratory step prior to targeted isolation of metabolites selected on the basis of HPLC-SPE-NMR results. Thus, natural product can be identified even in a crude extract using very small samples, all compounds giving rise to identifiable HPLC peaks (UV or MS traces) can be identified, and novel and otherwise interesting secondary metabolites can be selected for preparative isolation (enabling pharmacological evaluation) based on their rigorously established chemical structure (and in perspective based on virtual screening, ligand docking, and other in silico technologies).

Very recently, the NPR group acquired a cryogenically cooled NMR microprobe and automatic liquid handling equipment as well as a new automated SPE (solid-phase extraction) device, which will further increase sensitivity and throughput of HPLC-SPE-NMR experiments. One important consequence of the availability of the cryoprobe is the possibility of direct detection of ¹³C resonances. Many interesting metabolites, particularly those of fungal origin, have strongly unsaturated carbon skeletons with many quaternary carbon atoms and only a few hydrogens. Such compounds are difficult to identify using inversely detected HSQC/HMQC and HMBC correlations, the only method available so far in the hyphenation mode.

Publications

Wubshet, S.G., K.T. Johansen, N.T. Nyberg, and J.W. Jaroszewski, Direct ¹³C NMR Detection in HPLC Hyphenation Mode: Analysis of Ganoderma lucidum Terpenoids. Journal of Natural Products, 2012. Accepted for publication 11/4-2012. http://dx.doi.org/10.1021/np200915c. 

Skaar, Irene; Jordheim, Monica; Byamukama, Robert; Mbabazi, Angella; Kiremire, Bernard T.; Wubshet, Sileshi; Andersen, Øyvind M. New Anthocyanidin and Anthocyanin Pigments from Blue Plumbago. <cite>J. Agric. Food Chem.</cite>, 2012, 60 (6): p 1510–1515

Johansen, K.T., S.G. Wubshet, N.T. Nyberg, and J.W. Jaroszewski, From Retrospective Assessment to Prospective Decisions in Natural Product Isolation: HPLC-SPE-NMR Analysis of Carthamus oxyacantha Journal of Natural Products, 2011. 74: p. 2454-2461

Anthony; Susset, Audrey; Tougerti, Asma; Gallego, Daniel; Ramani, Sudarsan Venkat; Kalyanikar, Malathi; Dolzhnikov, Dmitriy S.; Wubshet, Sileshi G.; Wang, Yilun; Cristol, Sylvain; Briois, Valerie; La Fontaine, Camille; Gauvin, Regis. M.; Paul, Jean-Francois; Berrier, Elise. An easily accessible Re-based catalyst for the selective conversion of methanol: evidence for an unprecedented active site structure through combined operando techniques. Chem. Commun., 2011, 47, p. 4285-4287