Christian Knittl-Frank

Supervisor: Nuno Maulide, University of Vienna

Co-Supervisor: Marko Mihovilovic, Vienna University of Technology


Start of the project: 15.05.2019

Title of the project: Collective Synthesis of Pentacyclic Polyhydroxlated Triterpenoids

Research topic of the student: 

Triterpenoid sapogenins (aglycons) and their corresponding glycosides (saponins) are a large family of secondary metabolites that exhibit diverse bioactivity. Many steroids, another class of secondary metabolites with a structural similarity to triterpenoids, are known GABAA receptor modulators.[1] The structural similarity makes triterpenoids compounds of interest compounds for investigation as GABAA ligands.

The triterpenoids can be further divided into several subfamilies of pentacyclic molecules: Oleananes, ursanes, gammaceranes, lupanes, and hopanes. Biological activities across the members of each subfamily are dominated by molecular substitution patterns.

For oleananes it was shown that modification on C-6 modulates anti-inflammatory activity.[2] However, from a synthetic point of view, C-6 functionalization was unprecedented in the literature. Our group has recently developed a method for C-6 functionalization that allowed access to more complex and higher oxidized oleananes. We plan to extend our methodology to other pentacyclic subfamilies and to further synthesize non-natural analogs for evaluation as GABAA receptor modulators.


[1]  Wang M. Front Endocrinol (Lausanne) 2011, 2:44. doi:10.3389/fendo.2011.00044.

[2]  (a) Manosroi A. et al. Chem. Biodivers. 2013, 10(8), 1448. doi: 10.1002/cbdv.201300149;
(b) Zhang J. et al. Phytochemistry 2014, 108, 157. doi: 10.1016/j.phytochem.2014.09.017.

Internship abroad: "Digitalizing Synthetic Chemistry", 01.02.2022 - 13.06.2022

Host lab: Lee Cronin lab; University of Glasgow, School of Chemistry, Glasgow, UK

Lab Rotation project "Enzymatic stereoselective oxidation" is arranged for 08/2022

Lab host: Marko Mihovilovic, Vienna University of Technology 

Link to Publications by Christian Knittl-Frank