Amino Aldehydes Revisited

Abstract

The enzymatic oxidation of amino alcohols was studied to address the long‐standing problem of product stability. Amino aldehydes, highly sought and unstable compounds, can be generated under mild conditions if they are immediately protected. Utilizing a range of alcohol dehydrogenases (ADHs) and semicarbazide as a scavenger, the enantioselective synthesis of protected amino aldehydes is possible. Glycerol dehydrogenase from Gluconobacter oxydans (GoGDH) displayed excellent enantioselectivity but limited substrate scope, whereas horse liver ADH catalyzed a broad range of conversions with low enantioselectivities.

Combination of Asymmetric Organo‐ and Biocatalysis in Flow Processes and Comparison with their Analogous Batch Syntheses

“…Based on these findings and literature data, [20] for the further flow process development of this chemoenzymatic cascade the S ‐enantioselective ADH030 and R ‐enantioselective ADH270 were chosen as enzyme components. It should be added that the commercial enzymes showed no precipitation in presence of higher amounts of water‐miscible organic solvents (acetone and isopropanol), which fulfils a further prerequisite to conduct a completely homogenous flow reaction.…”

Exploring the abundance of oleate hydratases in the genus Rhodococcus—discovery of novel enzymes with complementary substrate scope

“…A novel oleate hydratase enzyme assay ADH010 has been reported to reduce 3-nonanone and AHD020 has been reported to reduce ethyl pyruvate by the enzyme manufacturer. Both enzymes have been reported to be inactive for the oxidation of rac-phenylalaninol (amino alcohol) and the reduction of 2-azidoacetophenone (azido ketone) (Mestrom et al 2017;Schrittwieser et al 2013). Interestingly, the reduced form of 3-nonanone, i.e.…”

Prebiotic Synthesis and Isomerization in Interstellar Analog Ice: Glycinal, Acetamide, and Their Enol Tautomers

“…Glycinal ( 1 , HCOCH 2 NH 2 ) along with its isomer acetamide ( 2 , CH 3 CONH 2 ) exemplify fundamental molecular building blocks in biochemistry and play a vital role in the structural integrity of cell walls of living organisms. Glycinal is thermodynamically less stable than 2 and rapidly undergoes condensation, making α‐amino aldehydes a challenging class of compounds to study [1] . This is surprising because of the biological significance of 1 , as it is prevalently involved in the metabolism of bacteria such as the model organism Escherichia Coli [2] .…”

“…Glycinal is thermodynamically less stable than 2 and rapidly undergoes condensation, making α-amino aldehydes a challenging class of compounds to study. [1] This is surprising because of the biological significance of 1, as it is prevalently involved in the metabolism of bacteria such as the model organism Escherichia Coli. [2] In interstellar chemistry, both 1 and 2 may serve as fundamental molecular building blocks and starting materials for key biological compounds like peptides, predominantly due to their bifunctional nature.…”

“…Note that the proposed radical mechanism differs drastically from biological peptide synthesis with amino acid condensation reactions, though previous ice experiments support the possibility of this mechanism. [3] Glycinal (1), by substitution of an alcohol (À OH) for the amine (À NH 2 ), is related to the simplest sugar-related compound glycolaldehyde (CH 2 OHCHO), which has already been detected in space. [4] We previously demonstrated the formation of glycolaldehyde and its isomer 1,2-ethenediol (HOCHCHOH) in interstellar ice analogs, which recently led to the detection of the latter in deep space.…”