Zacharias Amara - New photochemical and non-photochemical routes to the antimalarial drug artemisinin
Abstract:
Artemisinin is a major antimalarial drug currently produced by a semi-synthetic route which involves a fermentation step and a key photochemical oxidation reaction. The costs associated with this process are currently too high to maintain a low market price and there is therefore a need for more affordable
manufacturing routes.
A first solution is the optimization of the current photochemical oxidation step which is low yielding.聽To circumvent this problem, we have worked on the design of more environmentally benign photochemical oxidations with visible light which rely on the adsorption of a commercial photocatalyst on silica.聽This rather straightforward and inexpensive approach has enabled the discovery of interesting surface effects which accelerate the conversion. This immobilization strategy can also be utilized to intensify photochemical oxidations in a fixed bed continuous flow reactor.
In a second part, we will present a series of alternative new semi-synthetic routes based on the valorisation of amorphadiene, a high yielding fermentation intermediate currently treated as a waste. We will show how photochemistry can be a highly cost-competitive solution to convert this compound into a key intermediate of the artemisinin synthesis.
Bio:
Zacharias Amara graduated with a Pharmaceutical Degree in 2008 and then with a PhD in organic chemistry in 2012 at the University of Paris-Sud. He then moved to the UK to work in green chemistry as a postdoctoral researcher at the University of Nottingham in the group of Pr Martyn Poliakoff and Pr Mike George. In 2015, he returned to Paris to start his independent career as an assistant professor at the National Conservatory of Arts and Crafts (Engineering School). He teaches organic chemistry and formulation chemistry. His interests lie in the development of new catalytic transformations, photochemistry and continuous flow processing applied to pharmaceutical synthesis. In 2017, he received an Ignition Grant Award from the ACS Green Chemistry Institute and in 2018, a grant from the Bill and Melinda Gates Foundation to carry out a new research program on the development of new routes to artemisinin.