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Michael addition is an important reaction to form C–C bonds. Different hydrolases (e.g., lipases, proteases, and D-aminoacylase) have been reported to catalyze C–C forming reactions, but the reaction mechanism is not entirely clear. This study examined several model Michael reactions catalyzed by lipases and amino acids in various solvents, and found that “‘water-like”’ functionalized ionic liquids (ILs) increased the reaction yield to 35-55% from 30% in triglyme and 17% in [BMIM][Tf2N]. Interestingly, tertiary amides as solvents remarkably increased the reaction yield (to up to 65–85%) and enantioselectivity (up to 71–84% ee) when catalyzed by porcine pancreatic lipase (PPL). Our experimental, spectroscopic, and computational studies discovered that the lipase catalysis can be attributed to basic amino acid residues as the catalysts to promote Michael addition, especially when tertiary amide solvents partially unfold the protein and expose its basic amino acid residues. 

Enzymatic carbon‒carbon (C–C) bond formation reactions have become an effective and invaluable tool for designing new biological and medicinal molecules, often with asymmetric features. This review provides a systematic overview of key C–C bond formation reactions and enzymes, with the focus of reaction mechanisms and recent advances. These reactions include aldol reaction, Henry reaction, Knoevenagel condensation, Michael addition, Friedel-Crafts alkylation and acylation, Mannich reaction, Morita–Baylis–Hillman (MBH) reaction, Diels-Alder reaction, acyloin condensations via Thiamine Diphosphate (ThDP)-dependent enzymes, oxidative and reductive C–C bond formation, C–C bond formation through C1 resource utilization, radical enzymes for C–C bond formation, and other C–C bond formation reactions. 

The chiral induced spin selectivity (CISS) effect, in which the structural chirality of a material determines the preference for the transmission of electrons with one spin orientation over that of the other, is emerging as a design principle for creating next-generation spintronic devices. CISS implies that the spin preference of chiral structures persists upon injection of pure spin currents and can act as a spin analyzer without the need for a ferromagnet. Here, we report an anomalous spin current absorption in chiral metal oxides that manifests a colossal anisotropic nonlocal Gilbert damping with a maximum-to-minimum ratio of up to 1000%. A twofold symmetry of the damping is shown to result from differential spin transmission and backscattering that arise from chirality-induced spin splitting along the chiral axis. These studies reveal the rich interplay of chirality and spin dynamics and identify how chiral materials can be implemented to direct the transport of spin current. 

Abstract The morphology and motion of auroras have been widely studied due to their indications on magnetospheric processes. Here, we report a new kind of “auroral curls,” which have wavelengths in the mesoscale (∼100 km) and propagate azimuthally. Utilizing data from the Chinese Antarctic Zhongshan Station (the all‐sky imager and the high‐frequency radar), the Active Magnetosphere and Planetary Electrodynamics Response Experiment and the Defense Meteorological Satellite Program, we analyze an event occurred on 23 April 2019. We find these curls are fine structures in the poleward boundary of multiple arcs. Corresponding field‐aligned currents manifest as a series of longitudinally arranged pairs, while ionospheric flow velocities nearby oscillate with periods in the Pc 5 band. Observational evidence suggests these curls are connected with ultra‐low frequency (ULF) waves, which opens the possibility of using auroras to globally image ULF waves. 

Abstract BACKGROUNDKnoevenagel condensation is an important tool for building carbon–carbon (CC) bonds, especially when catalyzed by enzymes to enable a potentially high chemo‐, regio‐ and/or stereoselectivity. Although many Knoevenagel condensation reactions are carried out in aqueous solutions, insoluble hydrophobic substrates often lead to poor catalytic efficiencies. The use of water‐miscible organic solvents improves the substrate solubilization, but usually induces activity suppression or inactivation of enzymes. There is a great need to develop alternative solvents for both substrate dissolution and enzyme compatibility in CC bond formation reactions. RESULTSOur group previously developed dual‐functionalized water‐mimicking ionic liquids (ILs) for the activation and stabilization of hydrolases (e.g. lipase and protease). In the present study, we evaluated the Knoevenagel condensation of 4‐chlorobenzaldehyde with acetylacetone, and found that porcine pancreas lipase in water‐mimicking ILs carrying ammonium, imidazolium and benzimidazolium cations enabled higher reaction rates (up to 3.22 μmol min⁻¹ g⁻¹lipase) and better yields thantert‐butanol, glymes and [BMIM][Tf₂N]. Interestingly, tertiary amide solvents such asN‐methyl‐2‐pyrrolidone (NMP),N,N‐dimethylformamide (DMF) andN,N‐dimethylacetamide (DMAc) led to 8.2‐ to 11.1‐fold increases in the initial rate (up to 35.66 μmol min⁻¹ g⁻¹lipase) when compared with dual‐functionalized ILs, which is likely due to some synergistic effect of these tertiary amides with the lipase. CONCLUSIONDual‐functionalized ILs based on ammonium, imidazolium and benzimidazolium cations improved Knoevenagel condensation reaction rates and yields when compared withtert‐butanol and glymes. Tertiary amides (NMP, DMF and DMAc) significantly increased the reaction rate. © 2024 The Authors.Journal of Chemical Technology and Biotechnologypublished by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI). 

Abstract Prostate cancer (PCa) is the most common invasive malignancy for men in the USA. The incidence and mortality rates of PCa are significantly higher among African American men, as compared to those in Caucasian men. Betulinic acid (BA) is a penta-cyclic triterpenoid that is often found in the bark of several species of plants. It possesses a variety of biological activities, including anti-cancer activities. We examined the cytotoxic effects and endoplasmic reticulum (ER) stress induced by BA and its ionic derivatives with PCa cells derived from African Americans and Caucasian men. The viability of all PCa cells was reduced by the BA compounds, and the cytotoxicity of these BA compounds was independent of ethnicity and androgen dependency. The BA compounds induced modest effects on ER stress proteins when compared with ER stress inducers, tunicamycin and thapsigargin. The induction of glucose regulated protein 78 (GRP78) was largely correlated with the expression of C/EBP homologous protein (CHOP) and cleaved poly [ADP-ribose] polymerase (PARP)/caspase-3 in the PCa cells. In summary, our data demonstrated that BA compounds impaired the growth of PCa cells regardless of ethnicity – through GRP78- and CHOP-independent pathways.