Whole‐Cell Photoenzymatic Cascades to Synthesize Long‐Chain Aliphatic Amines and Esters from Renewable Fatty Acids

Abstract

Long‐chain aliphatic amines such as (S,Z)‐heptadec‐9‐en‐7‐amine and 9‐aminoheptadecane were synthesized from ricinoleic acid and oleic acid, respectively, by whole‐cell cascade reactions using the combination of an alcohol dehydrogenase (ADH) from Micrococcus luteus, an engineered amine transaminase from Vibrio fluvialis (Vf‐ATA), and a photoactivated decarboxylase from Chlorella variabilis NC64A (Cv‐FAP) in a one‐pot process. In addition, long chain aliphatic esters such as 10‐(heptanoyloxy)dec‐8‐ene and octylnonanoate were prepared from ricinoleic acid and oleic acid, respectively, by using the combination of the ADH, a Baeyer–Villiger monooxygenase variant from Pseudomonas putida KT2440, and the Cv‐FAP. The target compounds were produced at rates of up to 37 U g−1 dry cells with conversions up to 90 %. Therefore, this study contributes to the preparation of industrially relevant long‐chain aliphatic chiral amines and esters from renewable fatty acid resources.

Intensification of Photobiocatalytic Decarboxylation of Fatty Acids for the Production of Biodiesel

“…In our experiments the turnover numbers for Cv FAP (TON=mol product ×mol Cv FAP −1 ) never exceeded 9.000. These turnover numbers are well in the range of TONs previously observed for Cv FAP [10–15] indicating that the light intensity itself is not the main parameter for Cv FAP inactivation. This supports the Cv FAP inactivation mechanism proposed by Scrutton and co‐workers, assuming that intermediate radical species occurring in the catalytic mechanism may cause inactivation of the biocatalyst [6] …”

“…Therefore, we became very interested in the recently reported photoactivated fatty acid decarboxylase from Chlorella variabilis NC64A ( Cv FAP) [4] . Upon illumination with visible light ( λ =450 nm) Cv FAP catalyzes the decarboxylation of a broad range of fatty acids [4–15] . However, photochemical processes are severely limited by current reactor designs involving external illumination.…”

Biocatalytic Reduction Reactions from a Chemist's Perspective

“… Examples of cascades involving TA‐catalysed stereoselective reductive amination. a) Starting from cyclohexanol yielding ω‐hydroxy hexanoic acid, which is transformed into ω‐amino hexanoic acid; [147a] b,c) starting from fatty acids involving ω‐hydroxylation; [145a, 147b,c] d) starting from unsaturated fatty acids involving hydration of the C=C double bond followed by oxidation and reductive amination and decarboxylation; [145] e) C−C bond formation prior to reductive amination; [143] f) combined with a stereoselective C=C bond reduction [53] g) in situ oxyfunctionalisation; [146] h) following in situ C−C bond formation [144a] . ADH: alcohol dehydrogenase; BVMO: Baeyer–Villiger monooxygenase; TA: transaminase; AlaDH: alanine dehydrogenase; AlkBGT: alkane monooxygenase; Hase: hydratase; Cv FAP: photoactivated fatty acid decarboxylase; ER: ene reductase; TK: transketolase; SAS: sodium anthraquinone sulfonate.…”

Biokatalytische Reduktionen aus der Sicht eines Chemikers

“… Beispiele für TA‐katalysierte (stereoselektive) reduktive Aminierung eingebettet in Kaskadenreaktionen. a) Ausgehend von Cyclohexanol zu ω‐Aminohexansäure über ω‐Hydroxyhexansäure; [147a] b und c) ausgehend von Fettsäuren mit ω‐Hydroxylierung als Schlüsselschritt; [145a, 147b,c] d) ausgehend von ungesättigten Fettsäuren als Sequenz aus C=C‐Hydratisierung, Oxidation, reduktiver Aminierung und Decarboxylierung; [145] e) mit vorgelagerter C−C‐Bindungsbildung; [143] f) kombiniert mit Stereoselektiver C=C‐Bindungsreduktion; [53] g) in situ Oxyfunktionalisierung zur Generierung der Carbonylgruppe [146] h) nach in situ C‐C‐Bindungsbildung [144a] ADH: Alcoholdehydrogenase; BVMO: Baeyer‐Villiger‐Monooxygenase; TA: Transaminase; AlaDH: Alanindehydrogenase; AlkBGT: Alkanmonooxygenase; Hase: Hydratase; Cv FAP: photoaktivierte Fettsäuredecarboxylase; ER: Enreduktase; TK: Transketolase; SAS: sodium anthraquinone sulfonate.…”

“…Seit einiger Zeit werden Transaminasen auch für die Synthese von ω‐Aminosäure(estern) in Betracht gezogen (Abbildung 26 a–c) [145a, 147] . Zieht man den Bulkcharakter dieser Polyamidbausteine in Betracht, zeigt sich die Ambition der Transaminasetechnologie über die Nische chiraler Produkte hinaus.…”