The conversion of saturated fatty acids to high value chiral hydroxy-acids and lactones poses anumber of synthetic challenges:t he activation of unreactive CÀHb onds and the need for regio-and stereoselectivity.H ere the first example of aw ild-type cytochrome P450 monooxygenase (CYP116B46 from Tepidiphilus thermophilus) capable of enantio-and regioselective C5 hydroxylation of decanoic acid 1 to (S)-5hydroxydecanoic acid 2 is reported. Subsequent lactonization yields (S)-d-decalactone 3,ahigh value fragrance compound, with greater than 90 %ee. Docking studies providearationale for the high regio-and enantioselectivity of the reaction.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Cytochrome P450 monooxygenases are able to catalyse a range of synthetically challenging reactions ranging from hydroxylation and demethylation to sulfoxidation and epoxidation. As such they have great potential for biocatalytic applications but are underutilised due to often-poor expression, stability and solubility in recombinant bacterial hosts. The use of self-sufficient P450 s with fused haem and reductase domains has already contributed heavily to improving catalytic efficiency and simplifying an otherwise more complex multi-component system of P450 and redox partners. Herein, we present a new addition to the class VII family with the cloning, sequencing and characterisation of the self-sufficient CYP116B62 Hal1 from Halomonas sp. NCIMB 172, the genome of which has not yet been sequenced. Hal1 exhibits high levels of expression in a recombinant E. coli host and can be utilised from cell lysate or used in purified form. Hal1 favours NADPH as electron donor and displays a diverse range of activities including hydroxylation, demethylation and sulfoxidation. These properties make Hal1 suitable for future biocatalytic applications or as a template for optimisation through engineering.

Cytochrome P450 monooxygenases are highly desired biocatalysts owing to their ability to catalyse a wide variety of chemically challenging C-H activation reactions. The CYP102A subfamily of enzymes are natural catalytically self-sufficient proteins consisting of a haem and FMN-FAD reductase domain fused in a single-component system. They catalyse the oxygenation of saturated and unsaturated fatty acids to produce primarily ω-1, ω-2 and ω-3 hydroxy acids. These monooxygenases have potential applications in biotechnology; however, their substrate range is still limited and there is a continued need to add diversity to this class of biocatalysts. Herein, we present the characterisation of two new members of this class of enzymes, CYP102A25 (BMar) from Bacillus marmarensis and CYP102A26 (PHal) from Pontibacillus halophilus, both of which express readily in a recombinant bacterial host. BMar exhibits the highest activity toward myristic acid and shows moderate activity towards unsaturated fatty acids. PHal exhibits broader activity towards mid-chain-saturated (C -C ) and unsaturated fatty acids. Furthermore, PHal shows good regioselectivity for the hydroxylation of myristic acid, targeting the ω-2 position for C-H activation.

No abstract

The conversion of saturated fatty acids to high value chiral hydroxy‐acids and lactones poses a number of synthetic challenges: the activation of unreactive C−H bonds and the need for regio‐ and stereoselectivity. Here the first example of a wild‐type cytochrome P450 monooxygenase (CYP116B46 from Tepidiphilus thermophilus) capable of enantio‐ and regioselective C5 hydroxylation of decanoic acid 1 to (S)‐5‐hydroxydecanoic acid 2 is reported. Subsequent lactonization yields (S)‐δ‐decalactone 3, a high value fragrance compound, with greater than 90 % ee. Docking studies provide a rationale for the high regio‐ and enantioselectivity of the reaction.