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Since their structural elucidation in 1935, the introduction and substitution of functional groups and the modification of the steroidal scaffolds have been a fertile ground of research for synthetic and medicinal chemists. The discovery of steroids with hormonal and pharmacological activity has stimulated tremendous efforts to the development of highly selective and efficient synthetic procedures. Despite the progress made, steroid chemistry remains challenging and the preparation of steroidal compounds of pharmaceutical interests and in clinical practice, often requires long and elaborated synthesis. In recent years, a new impetus in the field came with the advent of enabling chemical technologies, such as continuous flow chemistry, which are exploited to overcome problems that arise from batch synthesis. Although it is still a niche sector, the use of flow technology in steroid synthesis and functionalization holds the premise to empower methodology development and to provide innovative tactics also for many hitherto uncharted chemistries. In this review, scientific contributions are reported and discussed in terms of flow set‐up and advantages offered concerning process efficiency, optimization, waste minimization, safety improvement, easy scale‐up and costs. We also highlight the main challenges, key improvements and the future trajectory in the application of continuous flow chemistry and its implementation to different disciplines such as photochemistry and biocatalysis with the ultimate goal of streamlining steroid synthesis. [ABSTRACT FROM AUTHOR]

We constructed a high-performance biosensor for detecting uric acid by immobilizing an engineered urate oxidase on gold nanoparticles deposited on a carbon-glass electrode. This biosensor showed a low limit-of-detection (9.16 nM), a high sensitivity (14 μA/μM), a wide range of linearity (50 nM–1 mM), and more than 28 days lifetime. [ABSTRACT FROM AUTHOR]

The l‐lysine‐ϵ‐dehydrogenase (LysEDH) from Geobacillus stearothermophilus naturally catalyzes the oxidative deamination of the ϵ‐amino group of l‐lysine. We previously engineered this enzyme to create amine dehydrogenase (AmDH) variants that possess a new hydrophobic cavity in their active site such that aromatic ketones can bind and be converted into α‐chiral amines with excellent enantioselectivity. We also recently observed that LysEDH was capable of reducing aromatic aldehydes into primary alcohols. Herein, we harnessed the promiscuous alcohol dehydrogenase (ADH) activity of LysEDH to create new variants that exhibited enhanced catalytic activity for the reduction of substituted benzaldehydes and arylaliphatic aldehydes to primary alcohols. Notably, these novel engineered dehydrogenases also catalyzed the reductive amination of a variety of aldehydes and ketones with excellent enantioselectivity, thus exhibiting a dual AmDH/ADH activity. We envisioned that the catalytic bi‐functionality of these enzymes could be applied for the direct conversion of alcohols into amines. As a proof‐of‐principle, we performed an unprecedented one‐pot "hydrogen‐borrowing" cascade to convert benzyl alcohol to benzylamine using a single enzyme. Conducting the same biocatalytic cascade in the presence of cofactor recycling enzymes (i.e. NADH‐oxidase and formate dehydrogenase) increased the reaction yields. In summary, this work provides the first examples of enzymes showing "alcohol aminase" activity. [ABSTRACT FROM AUTHOR]