The combination of enzymes with traditional chemical catalysts unifies the high selectivity of the former with the versatility of the latter. A major challenge of this approach is the difference in the optimal reaction conditions for each catalyst type. In this work, we combined a cofactor-free decarboxylase with a ruthenium metathesis catalyst to produce high-value antioxidants from bio-based precursors. As suitable ruthenium catalysts did not show satisfactory activity under aqueous conditions, the reaction required the use of an organic solvent, which in turn significantly reduced enzyme activity. Upon encapsulation of the decarboxylase in a cryogel, the decarboxylation could be conducted in an organic solvent, and the recovery of the enzyme after the reaction was facilitated. After an intermediate drying step, the subsequent metathesis in pure organic solvent proved to be straightforward. The synthetic utility of the cascade was demonstrated by the synthesis of the antioxidant 4,4'-dihydroxystilbene in an overall yield of 90 %.

OleT from Jeotgalicoccus sp. ATCC 8456 catalyzes the decarboxylation of ω‐functionalized fatty acids to the corresponding alkenols, which can themselves serve as starting material for the synthesis of polymers and fine chemicals. To show the versatility of possible reactions, a series of in vitro reaction cascades was developed where an alkenol produced by the decarboxylation of ω‐hydroxy fatty acids can be further converted into alkenylamines and diols. By coupling OleT with an alcohol dehydrogenase or alcohol oxidase as well as an amino‐transaminase, an oxidative decarboxylation followed by the oxidation of the terminal alcohol and a subsequent reductive transamination could be carried out. By using different cofactors or electron sources, the reactions could be performed sequentially or simultaneously. The combination of enzymatic decarboxylation with a ruthenium catalyst in a chemo‐enzymatic cascade provides a novel way to synthesize long‐chain diols.

Benzylic AdoMet analogs enable highly efficient enzymatic transfer of norbornenes to nucleic acids and subsequent tetrazine ligation.

No abstract

Eukaryotic mRNAs possess 5′ caps that are determinants for their function. A structural characteristic of 5′ caps is methylation, with this feature already present in early eukaryotes such as Trypanosoma. While the common cap‐0 (m7GpppN) shows a rather simple methylation pattern, the Trypanosoma cap‐4 displays seven distinguished additional methylations within the first four nucleotides. The study of essential biological functions mediated by these unique structural features of the cap‐4 and thereby of the metabolism of an important class of human pathogenic parasites is hindered by the lack of reliable preparation methods. Herein we describe the synthesis of custom‐made nucleoside phosphoramidite building blocks for m62Am and m3Um, their incorporation into short RNAs, the efficient construction of the 5′‐to‐5′ triphosphate bridge to guanosine by using a solid‐phase approach, the selective enzymatic methylation at position N7 of the inverted guanosine, and enzymatic ligation to generate trypanosomatid mRNAs of up to 40 nucleotides in length. This study introduces a reliable synthetic strategy to the much‐needed cap‐4 RNA probes for integrated structural biology studies, using a combination of chemical and enzymatic steps.

Gene expression is tightly regulated in all domains of life, with post-transcriptional regulation being more pronounced in higher eukaryotes. Optochemical and optogenetic approaches enable the actuation of many underlying processes...

Correction for ‘A benzylic linker promotes methyltransferase catalyzed norbornene transfer for rapid bioorthogonal tetrazine ligation’ by F. Muttach et al., Chem. Sci., 2017, DOI: ; .

The spatial and temporal control of gene expression at the post-transcriptional level is essential in eukaryotic cells and developing multicellular organisms. In recent years optochemical and optogenetic tools have enabled...