Savile, Janey, Mundorff, Moore, Tam, Jarvis, Colbeck, Krebber, Fleitz, Brands, Devine, Huisman, and Hughes. Biocatalytic Asymmetric Synthesis of Chiral Amines from Ketones Applied to Sitagliptin Manufacture. Science, 2010, 329, 305-309. DOI: 10.1126/science.1188934.
Here’s a short follow-up on this previous post, which covered a biocatalytic reaction developed by Codexis to make the key intermediate in the synthesis of Merck’s drug montelukast (aka Singulair). The 2010 Presidential Green Chemistry Awards were just announced, and the award for “Greener Reaction Conditions” went to Merck and Codexis for developing an enantioselective biocatalyst for the synthesis of sitagliptin, Merck’s blockbuster anti-diabetes drug (aka Januvia). This work is also the subject of a recently-published Science paper from Merck and Codexis.
The paper describes the development of an enzyme-catalyzed replacement for the final reaction in the synthesis of sitagliptin, in which a ketone functionality is converted into an amine. (more…)
“An efficient didehydroxylation method for the biomass-derived polyols glycerol and erythritol. Mechanistic studies of a formic acid-mediated deoxygenation” Arceo, E.; Marsden, P.; Bergman, R. G.; Ellman, J. A. Chemical Communications, 2009, 23, 3357. 10.1039/b907746d
A major focus in the area of “green” methods development is the mild and selective removal of functionality from readily available bio-derived feed stocks. Unlike petrochemical derived starting materials, the majority of biomass is highly oxygenated (think carbohydrates or lignin), and before the carbon embedded within this framework can be used for all-purpose chemical manufacturing the oxygen must be removed. (more…)
“Quantification of Water Solubilized CdSe/ZnS Quantum Dots in Daphnia magna” N. A. Lewinski, H Zhu, H J Jo, D. Pham, R R Kamath, C R Ouyang, C D Vulpe, V L Colvin, and R A Drezek. Environ. Sci. Technol. 2010, 1841-1846. 10.1021/es902728a
“Quantum Dot Weathering Results in Microbial Toxicity” S Mahendra, H Zhu, V L Colvin, P J Alvarez. Environ. Sci. Technol. 2008, 9424-9430. 10.1021/es8023385
The goal of green chemistry is to design chemicals and chemical processes which are inherently less toxic. For the emerging discipline of nanoscience, the potential toxicological properties remain largely unknown. That said I would like to discuss two related articles concerning the fate and toxicity of nanoparticles (NPs) in the aquatic environment. I like this set of articles because they are both simple, and yet give a hint of the complexities involved with understanding NP fate and toxicity. The more recent, examines the interaction between CdSe/ZnS NPs with Daphnia (a model species for aquatic toxicity). And the original article that drew my attention to this work concerned the same NP and studies the effect that chemical degradation has on NP toxicity. (more…)