Abstract Vicinal halohydrins are key building blocks to produce bioactive molecules and drugs, especially if they can be obtained in enantiomerically pure form. In this study, we present a bi‐enzymatic sequence that allows to obtain vic ‐halohydrins through a photochemoenzymatic olefin hydroxy halogenation followed by a lipase catalysed kinetic resolution. The absolute configuration of the resulting products was determined using Mosher's method
Abstract Background Acute Kidney Injury (AKI) is a very frequent condition, occurring in about one in three patients admitted to an intensive care unit (ICU). AKI is a syndrome defined as a sudden decrease in glomerular filtration rate. However, this unified definition does not reflect the various mechanisms involved in AKI pathophysiology, each with its own characteristics and sensitivity to therapy. In this study, we aimed at developing an innovative machine learning based method able to subphenotype AKI according to its pattern of risk factors. Methods We adopted a three-step pipeline of analyses. Firstly, we looked for factors associated with AKI using a generalized additive model. Secondly, we calculated the importance of each identified AKI related factor in the estimated AKI risk to find the main risk factor for AKI, at the single patient level. Lastly, we clusterized AKI patients according to their profile of risk factors and compared the clinical characteristics and outcome of every cluster. We applied this method to a cohort of severe Covid19 patients hospitalized in the ICU of Geneva University Hospitals. Results Among the 250 patients analyzed, we found ten factors associated with AKI development. Using the individual expression of these factors, we identified three groups of AKI patients, based on the use of Lopinavir/Ritonavir, a prior history of diabetes mellitus and baseline eGFR and ventilation. The three clusters expressed distinct characteristic in terms of AKI severity and recovery, metabolic patterns and ICU mortality. Conclusion We propose here a new method to phenotype AKI patients according to their most important individual risk factors for AKI development. When applied to an ICU cohort of Covid19 patients, we were able to differentiate three groups of patients. Each expressed specific AKI characteristics and outcomes, which probably reflects a distinct pathophysiology.
Quinol derivatives of estrogens are effective pro-drugs in steroid replacement therapy. Here, we report that these compounds can be synthesized in one-pot conditions and high yield by blue LED-driven photo-oxygenation of parent estrogens. The oxidation was performed in buffer and eco-certified 2-methyltetrahydrofuran as the two-liquid-phase reaction solvent, and in the presence of meso-tetraphenyl porphyrin as the photosensitizer. Two steroidal prodrugs 10β, 17β-dihydroxyestra-1,4-dien-3-one (DHED) and 10β-Hydroxyestra-1,4-diene-3,17-dione (HEDD) were obtained with high yield and selectivity.
The use of privileged scaffolds as starting point for the construction of libraries of bioactive compounds is a widely used strategy in drug discovery and development. Scaffold decoration, morphing and hopping are additional techniques that allow to modify the privileged framework chosen and better explore the chemical space around it. In this study, two series of highly functionalized pyrimidine and pyridine derivatives were synthesized by scaffold morphing approach of triazine compounds obtained previously as antiviral agents. Newly synthesized azines were evaluated against lymphoma, hepatocarcinoma, and colon epithelial carcinoma cells showing in five cases acceptable to good anticancer activity associated to low cytotoxicity on healthy fibroblasts. Finally, ADME in vitro studies were conducted on the best derivatives of the two series showing good passive permeability and resistance to metabolic degradation.
Photo‐catalysts based on the immobilization of meso‐TPP on lignin‐nanoparticles were prepared and applied in the one‐pot oxidative coupling of aromatic amines to N‐alkyl imines. Heterogeneous catalysts were effective in both homo‐coupling and cross‐coupling conditions, affording desired products in high yield. Among the immobilization procedures tested, the dialysis method afforded the most effective photo‐catalyst, which was characterized by the lower energy gap between the HOMO and LUMO of lignin. Lignin‐nanoparticles alone showed the capacity to catalyse the oxidative coupling, suggesting the possibility of a synergy effect with immobilized meso‐TPP. The sustainability of the procedure was confirmed by the use of the photo‐catalyst for more runs.
Abstract The synthesis of both enantiomers of a key intermediate in the synthesis of halofuginone was accomplished by a Candida antarctica lipase B (CAL-B)-catalyzed kinetic resolution of the corresponding racemate. When the resolution was carried out in the versatile solvent cyclopentyl methyl ether (CPME) using p-chlorophenylbutyrate (PCPB) as the acylating reagent, the highest enantiomeric ratio (E) values were measured, and highly enantioenriched (95% ee) compounds could be obtained in a single iteration. As an example, one of the two enantiomers was used as a starting material to prepare (+)-halofuginone in a three-step procedure.
Abstract The one‐pot stereoselective synthesis of ( S )‐flavanones from 2′‐hydroxyacetophenone and substituted aromatic aldehydes was obtained by a double‐face promiscuous chemo‐enzymatic cascade of porcine pancreas and Mucor javanicus lipases. The reaction pathway comprises: A) cross‐aldol condensation catalysed by porcine pancreas lipase to yield chalcone intermediates; B) unprecedented intramolecular oxa‐Michael addition of chalcone intermediates to ( S )‐flavanones. Mucor javanicus lipase was the most effective enzyme in step B. Imidazole and 2‐methylimidazole were studied as additive in order to improve the efficacy of the overall transformation. The sustainability of the chemo‐enzymatic cascade was increased by immobilization of lipases on cross‐linked hydroxy‐methylated kraft lignin nanoparticles, by use of concanavalin A. Immobilization conferred considerable stability and reusability at the system for 4 runs. Noteworthy, the reaction mixture was significantly enriched in ( S )‐flavanones under both homogeneous and heterogeneous conditions. Computational studies encompassing docking and molecular dynamic analyses showed the role played by evolutionary conserved oxyanion holes and catalytic triad of Mucor javanicus lipase in the stereocontrol of the intra‐molecular oxa‐Michael addition.
Molecular hybridization is a widely used strategy in drug discovery and development processes that consists in the combination of two bioactive compounds toward a novel entity. In the current study, two libraries of hybrid derivatives coming from the linkage of sesquiterpene counterparts dihydroartemisinin and artesunic acid with a series of monoterpenes were synthesized and evaluated by cell viability assay on primary and metastatic melanoma cell lines. Almost all the obtained compounds showed micromolar antimelanoma activity and selectivity toward the metastatic form of this cancer. Four hybrid derivatives containing perillyl alcohol, citronellol, and nerol as monoterpene counterpart, emerged as the best compounds of the series, with nerol being active in combination with both sesquiterpenes, dihydroartemisinin and artesunic acid. Preliminary studies on the mechanism of action have shown the dependence of the pharmacological activity of newly synthesized hybrids on the formation of carbon- and oxygen-centered radical species. This study demonstrated the positive modulation of the pharmacodynamic effect of artemisinin semisynthetic derivatives dihydroartemisinin and artesunic acid due to the hybridization with monoterpene counterparts.
