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Magneto‐Archimedes levitation (MagLev) enables the separation of powdered mixtures of illicit drugs (cocaine, methamphetamine, heroin, fentanyl, and its analogues), adulterants, and diluents based on density, and allows the presumptive identification of individual components. Small samples (mass <50 mg), with low concentrations of illicit drugs, present a particular challenge to analysis for forensic chemists. The MagLev device, a cuvette containing a solution of paramagnetic gadolinium(III) chelate in a non‐polar solvent, placed between two like‐poles‐facing NdFeB magnets, allowed separation of seven relevant compounds simultaneously. In particular, initial separation with MagLev, followed by characterization by FTIR‐ATR, enabled identification of fentanyl in a sample of fentanyl‐laced heroin (1.3 wt % fentanyl, 2.6 wt % heroin, and 96.1 wt % lactose). MagLev allows identification of unknown powders in mixtures and enables confirmatory identification based on structure‐specific techniques. [ABSTRACT FROM AUTHOR]

Within a newly identified set of flavin-containing monooxygenases (FMOs) from Rhodococcus jostii RHA1, we have identified three monooxygenases (FMO-E, FMO-F, and FMO-G) that are effective in catalyzing Baeyer-Villiger oxidations. These type II FMOs display relaxed coenzyme specificity by accepting both NADPH (reduced form of nicotinamide adenine dinucleotide phosphate) and NADH (reduced form of nicotinamide adenine dinucleotide), as a coenzyme, which is a novel and attractive feature among biocatalysts capable of conducting Baeyer-Villiger oxidations. We purified FMO-E and determined that the Michaelis constants for both coenzymes were in the micromolar range, whereas the activity was highest for NADH. By using the stopped-flow technique, formation of a peroxyflavin-enzyme intermediate was observed, which indicated that type II FMOs follow a catalytic mechanism similar to that of other class B flavoprotein monooxygenases. A set of cyclobutanones and cyclohexanones were used to probe the regio- and enantioselectivity of all three recombinant monooxygenases. The biocatalysts readily accepted small cyclic ketones, which enabled the conversion of previously poorly accepted substrates by other monooxygenases (especially norcamphor), and exhibited excellent and unique regio- and enantioselectivities. Sequence analysis revealed that type II FMOs that act as Baeyer-Villiger monooxygenases contain a unique N-terminal domain. Sequence conservation in this protein domain can be used to identify new NADH-dependent Baeyer-Villiger monooxygenases, which would facilitate future biocatalyst discovery efforts. [ABSTRACT FROM AUTHOR]

Smart catalysis cuts it short: Natural (S,S)‐Aerangis lactone and its epimer are synthesized with excellent optical purity by using in‐line hyphenation of continuous flow reactors and batch biotransformations. Optimization of the reaction steps and engineering of the reactor interfaces leads to a simple and efficient setup, which demonstrates how multistep syntheses can be streamlined into a single‐operation protocol. [ABSTRACT FROM AUTHOR]

Rücktitelbild: Analysis of Powders Containing Illicit Drugs Using Magnetic Levitation (Angew. Wie J. S. Bozenko, G. M. Whitesides et al. in ihrem Forschungsartikel auf S. 884 zeigen, trennt das Verfahren die Verbindungen basierend auf ihren unterschiedlichen Dichten in dem linearen Dichtegradienten, der in der Lösung gebildet wird. Die schwebenden Verbindungen (siehe Bild, aufgenommen mit gekreuzten Polarisatoren) sind gängige polare Verfälschungs- und Verdünnungsmittel, die zum Verschneiden illegaler Drogen verwendet werden. [Extracted from the article]

We report on the unexpected finding that click modification of iduronyl azides results in a conformational flip of the pyranose ring, which led to the development of a new strategy for the design of superior enzyme substrates for the diagnostic assaying of iduronate-2-sulfatase (I2S), a lysosomal enzyme related to Hunter syndrome. Synthetic substrates are essential in testing newborns for metabolic disorders to enable early initiation of therapy. Our click-flipped iduronyl triazole showed a remarkably better performance with I2S than commonly used O -iduronates. We found that both O - and triazole-linked substrates are accepted by the enzyme, irrespective of their different conformations, but only the O -linked product inhibits the activity of I2S. Thus, in the long reaction times required for clinical assays, the triazole substrate substantially outperforms the O -iduronate. Applying our click-flipped substrate to assay I2S in dried blood spots sampled from affected patients and random newborns significantly increased the confidence in discriminating between these groups, clearly indicating the potential of the click-flip strategy to control the biomolecular function of carbohydrates., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)