Chemistry Seminar – Nov. 12

Characterization of (2E)‐3‐[4,5‐bis(2H‐1,3‐benzodioxol‐5‐yl)‐1‐methyl‐1H‐
pyrrol‐2‐yl]prop‐2‐enoic acid (10B-9) Inhibition of Carbonyl Reductase

Anthracycline treatments are effective against many forms of cancer but are limited in dosage due to cardiotoxicity. The cardiotoxicity has been linked to the reduction of the anthracycline drug to alcohol metabolites. Carbonyl reductase catalyzes the NADPH-dependent reduction of anthracyclines and has been shown to be a risk factor in the development of anthracycline-induced cardiotoxicity. Therefore, carbonyl reductase is a clinical target for drugs that could reduce the risk of cardiotoxicity. The goal of this research is to characterize (2E)‐3‐[4,5‐bis(2H‐1,3‐benzodioxol‐5‐yl)‐1‐methyl‐1H‐pyrrol‐2‐yl]prop‐2‐enoic acid (10B-9) inhibition of human carbonyl reductase and to assess its potential as a drug that reduces the cardiotoxicity of anthracyclines. 10B-9 inhibition was characterized and found to be an uncompetitive inhibitor against both varied NADPH and the carbonyl substrate, menadione. The Kii values were estimated to be in the range of 6-9 μM. This pattern of inhibition is consistent with 10B-9 binding to the enzyme-NADP+ binary complex. 10B-9 binding to the enzyme-NADP+ binary complex was confirmed with protein fluorescence quenching studies where the Kd (9 ± 1 μM) was found to be consistent with the Kii values. This characterization is the basis for possible future drug development of 10B-9 to be paired with anthracycline treatments.

Characterization of metabolites for use in C13 NMR

The increase of CO2 in the atmosphere has led to an overall increase of temperature which has melted the ice caps, and led to extreme climate changes. In order to correct the damage done, the production of CO2 must stop, but a large amount of CO2 must also be sequestered from the atmosphere. A major contributor to carbon capture is the biosphere, specifically trees and grass, however these only act as temporary storage, and CO2is released back into the atmosphere in most natural decaying processes. The processes by which biomass is decomposed has been taken advantage of for centuries through fermentation, however this process is only a maximum of 66.7% efficient, and still produces a significant amount of carbon dioxide. Clostridium Thermocellum is a thermophilic anaerobe that has been used to produce biofuel through fermentation, and it has been suggested that it has the ability to incorporate CO2 directly into its metabolic pathways. Research done at the national renewable energy lab has been successful in proposing a novel possible pathway, but in order to test the hypothesis, the metabolites involved need to be characterized in solution. Sodium pyruvate labeled with C13 isotopes, along with C13labeled glucose, and sodium bicarbonate were analyzed with carbon 13 NMR techniques at various pH’s and temperatures. The data recovered was consistent, and there were interesting behaviours especially with bicarbonate and pyruvate. Compared to the data in the literature, their results make sense and once they are repeated with a standard in the solution, they can be used as a reference for In-Cell NMR experiments.