Biocatalytic Enantioselective Hydroaminations for Production of N‐Cycloalkyl‐Substituted L‐Aspartic Acids Using Two C−N Lyases

Abstract

N-cycloalkyl-substituted amino acids have wide-ranging applications in pharma-and nutraceutical fields. Here we report the asymmetric synthesis of various N-cycloalkyl-substituted laspartic acids using ethylenediamine-N,N'-disuccinic acid lyase (EDDS lyase) and a previously engineered variant of methylaspartate ammonia lyase (MAL-Q73A) as biocatalysts. Particularly, EDDS lyase shows broad non-natural substrate promiscuity and excellent enantioselectivity, allowing the selective addition of homo-and heterocycloalkyl amines (comprising four-, five-and sixmembered rings) to fumarate, giving the corresponding N-cycloalkyl-substituted l-aspartic acids with > 99% e.e. This biocatalytic methodology offers an alternative synthetic choice to prepare difficult N-cycloalkyl-substituted amino acids. Given its very broad amine scope, EDDS lyase is an exceptionally powerful synthetic tool that nicely complements the rapidly expanding toolbox of biocatalysts for asymmetric synthesis of noncanonical amino acids.

Aminocarboxylic acids related to aspergillomarasmine A (AMA) and ethylenediamine-N,N′-disuccinic acid (EDDS) are strong zinc-binders and inhibitors of the metallo-beta-lactamase NDM-1

“…Recently, we reported that ethylenediamine-N,N 0 -disuccinic acid (EDDS) lyase naturally catalyzes a reversible two-step sequential addition of ethylenediamine (2) to two molecules of fumaric acid (3), giving (S)-N-(2-aminoethyl)aspartic acid (AEAA, 4) as an intermediate and (S,S)-EDDS (5) as the final product (Table 1A). 12 EDDS lyase was subsequently found to have broad substrate promiscuity, [13][14][15] accepting a wide range of amino acids with terminal amino groups (6a-k) for regio-and stereoselective addition to fumarate, thus providing a straightforward biocatalytic method for the asymmetric synthesis of AMA (1a), AMB (1b), and related aminocarboxylic acids (1c-k, Table 1B). 13 To further explore the substrate scope of EDDS lyase, as well as to prepare a small library of EDDS derivatives as potential NDM-1 inhibitors, 16 we here describe the EDDS-lyase catalyzed reaction of fumaric acid with various diamines containing different aliphatic linkers between the two amino functional groups (7a-i) ( Table 2).…”

Engineered C–N Lyase: Enantioselective Synthesis of Chiral Synthons for Artificial Dipeptide Sweeteners

“…We continued our investigations by testing whether EDDS lyase, which has previously been shown to possess an exceptionally broad amine scope, [18][19][20] can accept 2 a as an unnatural substrate in the hydroamination of 1. Pleasingly, EDDS lyase accepted 2 a for addition to 1, giving rise to 3 a.…”

“…Here we report the engineering of an effective C-N lyase, based on ethylenediamine-N,N'-disuccinic acid (EDDS) lyase from Chelativorans sp. BNC1, [18][19][20] for the enantioselective syntheses of l-3 a and l-3 f, precursors to neotame and advantame, respectively, as well as related chiral synthons for aspartame-based sweeteners starting from the simple nonchiral compound fumaric acid (1, Scheme 1 C). This newly engineered C-N lyase shows a 1140-fold increase in activity for the selective hydroamination of fumarate compared to that of the wild-type enzyme, opening up new opportunities to design practical multienzymatic processes for the more sustainable and step-economic synthesis of an important class of food additives.…”

Recent Applications of Carbon‐Nitrogen Lyases in Asymmetric Synthesis of Noncanonical Amino Acids and Heterocyclic Compounds

“…Her current research interests include exploring the reactivity of enzymes from natural product biosynthesis pathways for producing pharmaceutically relevant molecules. [16][17][18][19][20][21] Ph, aryl H H RgPAL, AvPAL, PcPAL phenylalanine, β-aryl α-alanines [6,[22][23][24][25][26] chelating compound widely used in industry for a wide range of applications, such as soil remediation, paper manufacturing, waste water treatment and so on. (S,S)-EDDS was isolated as a secondary metabolite from the actinomycete Amycolatopsis japonicum, hypothetically serving as a scavenger of zinc (zincophore) and its bioproduction was strictly repressed by zinc.…”

“…BNC1 was also employed for enantioselective synthesis of complex N-cycloalkyl substituted l-aspartic acids, which are structurally distinct from its natural substrates ( Figure 5). [17] Reactions were performed with fumaric acid, various homo-and heterocycloalkyl amines (comprising four-, five-and six-membered rings) and EDDS lyase at pH 8.5 and room temperature. EDDS lyase exhibited broad substrate promiscuity, accepting a variety of cycloalkylamines in hydroamination of fumarate to give the corresponding N-cycloalkyl-l-aspartic acids with excellent enantioselectivity (ee > 99 %).…”