Lipase kinetic enantiomeric resolution of 1-heteroarylethanols

Enantioselective Bioreduction of Medicinally Relevant Nitrogen-Heteroaromatic Ketones

We herein report an enantioselective bioreduction of ketones that bear the most frequently used nitrogen-heteroaromatics in FDA-approved drugs. Ten varieties of these nitrogen-containing heterocycles were systematically investigated. Eight categories were studied for the first time and seven types were tolerated, significantly expanding the substrate scope of plant-mediated reduction. By use of purple carrots in buffered aqueous media with a simplified reaction setup, this biocatalytic transformation was achieved within 48 h at ambient temperature, offering medicinal chemists a pragmatic and scalable tool to access a broad variety of nitrogen-heteroaryl-containing chiral alcohols. With multiple reactive sites, the structurally diverse set of chiral alcohols can be used for library compound preparation, early route-scouting activities, and synthesis of other pharmaceutical molecules, favorably accelerating medicinal chemistry campaigns.

Environmentally-friendly strategy for separation of 1,3-propanediol using biocatalytic conversion

Glycerol waste from the biodiesel production can be used as a carbon source in the production of 1,3-propanediol (1,3-PD) through microbial fermentation. However, downstream processing is a major bottleneck that restricts its biological production. Here, we investigated an environmentally-friendly method to enzymatically separate 1,3-PD. The transformation of 1,3-PD to an ester was achieved by exploiting the esterification reaction with fatty acids under lipase catalysis. The reaction efficiency was optimized using different poly-alcohols that were existed in the fermentation broth reacted with a fatty acid. Whereas the 1,3-PD conversion reached 62%, only a 0.06% and 0.08% conversion was reached for 2,3-butanediol and glycerol, illustrating the former's more efficient separation. The recovery efficiency of 1,3-PD was 96%. Finally, 1,3-PD was obtained by lipase-directed ester hydrolysis. Taken together, the bio-catalyzed separation process presented here is a novel and promising method for recovering 1,3-PD.