Novel Evodiamine-Based Sulfonamide Derivatives as Potent Insecticide Candidates Targeting Insect Ryanodine Receptors.

Pests represent an important impediment to efficient agricultural production and pose a threat to global food security. On the basis of our prior research focused on identifying insecticidal leads targeting insect ryanodine receptors (RyRs), we aimed to identify evodiamine scaffold-based novel insecticides. Thus, a variety of evodiamine-based derivatives were designed, synthesized, and assessed for their insecticidal activity against the larvae of Mythimna separata (M. separata) and Plutella xylostella (P. xylostella). The preliminary bioassay results revealed that more than half of the target compounds exhibited superior activity compared to evodiamine, matrine, and rotenone against M. separata. Among these, compound 21m displayed the most potent larvicidal efficiency, with a remarkable mortality rate of 93.3% at 2.5 mg/L, a substantial improvement over evodiamine (10.0% at 10 mg/L), matrine (10.0% at 200 mg/L), and rotenone (30.0% at 200 mg/L). In the case of P. xylostella, compounds 21m and 21o displayed heightened larvicidal activity, boasting LC50 values of 9.37 × 10-2 and 0.13 mg/L, respectively, surpassing that of evodiamine (13.41 mg/L), matrine (291.78 mg/L), and rotenone (18.39 mg/L). A structure-activity relationship analysis unveiled that evodiamine-based derivatives featuring a cyclopropyl sulfonyl group at the nitrogen atom of the B ring and a fluorine atom in the E ring exhibited more potent larvicidal effects. This finding was substantiated by calcium imaging experiments and molecular docking, which suggested that 21m could target insect RyRs, including resistant mutant RyRs of P. xylostella (G4946E and I4790M), with higher affinity than chlorantraniliprole (CHL). Additionally, cytotoxicity assays highlighted that the potent compounds 21i, 21m, and 21o displayed favorable selectivity and low toxicity toward nontarget organisms. Consequently, compound 21m emerges as a promising candidate for further development as an insecticide targeting insect RyRs.

Live cell in situ lysosomal GCase activity correlates to alpha-synuclein levels in human differentiated neurons with LRRK2 and GBA1 mutations.

Introduction: Heterozygous mutations in GBA1, which encodes the lysosomal hydrolase glucocerebrosidase (GCase), are a common risk factor for the neurodegenerative movement disorder Parkinson's disease (PD). Consequently, therapeutic options targeting the GCase enzyme are in development. An important aspect of this development is determining the effect of potential modifying compounds on GCase activity, which can be complicated by the different methods and substrate probes that are commonly employed for this purpose. Methods: In this study, we employed the GCase substrate probe 5-(pentafluorobenzoylamino)fluorescein di-D-glucopyranoside (PFB-FDGlu) in combination with live cell imaging to measure GCase activity in situ in the lysosome. Results: The live cell assay was validated using the GCase inhibitor conduritol-B-epoxide and with GBA1 knockout neural cells and was then used to assess GCase activity in iPSC differentiated into neural stem cells and neurons that were obtained from idiopathic PD patients and PD patients with the LRRK2 G2019S and GBA N370S mutations, as well as controls (n = 4 per group). Heterogeneity in GCase activity was observed across all groups. However, a significant inverse correlation between GCase activity and levels of alpha-synuclein protein was observed. Discussion: The live cell imaging assay for GCase activity could be useful for further understanding the role of GCase in PD and screening potential modifying compounds in differentiated human cell models.

A small molecule toll-like receptor antagonist rescues α-synuclein fibril pathology.

The propagation and accumulation of pathological α-synuclein protein is thought to underlie the clinical symptoms of the neurodegenerative movement disorder Parkinson's disease (PD). Consequently, there is significant interest in identifying the mechanisms that contribute to α-synuclein pathology, as these may inform therapeutic targets for the treatment of PD. One protein that appears to contribute to α-synuclein pathology is the innate immune pathogen recognition receptor, toll-like receptor 2 (TLR2). TLR2 is expressed on neurons, and its activation results in the accumulation of α-synuclein protein; however, the precise mechanism by which TLR2 contributes to α-synuclein pathology is unclear. Herein we demonstrate using human cell models that neuronal TLR2 activation acutely impairs the autophagy lysosomal pathway and markedly potentiates α-synuclein pathology seeded with α-synuclein preformed fibrils. Moreover, α-synuclein pathology could be ameliorated with a novel small molecule TLR2 inhibitor, including in induced pluripotent stem cell-derived neurons from a patient with PD. These results provide further insight into how TLR2 activation may promote α-synuclein pathology in PD and support that TLR2 may be a potential therapeutic target for the treatment of PD.

Real-Space Investigation of the Multiple Halogen Bonds by Ultrahigh-Resolution Scanning Probe Microscopy.

The chemical bond is of central interest in chemistry, and it is of significance to study the nature of intermolecular bonds in real-space. Herein, non-contact atomic force microscopy (nc-AFM) and low-temperature scanning tunneling microscopy (LT-STM) are employed to acquire real-space atomic information of molecular clusters, i.e., monomer, dimer, trimer, tetramer, formed on Au(111). The formation of the various molecular clusters is due to the diversity of halogen bonds. DFT calculation also suggests the formation of three distinct halogen bonds among the molecular clusters, which originates from the noncovalent interactions of Br-atoms with the positive potential H-atoms, neutral potential Br-atoms, and negative potential N-atoms, respectively. This work demonstrates the real-space investigation of the multiple halogen bonds by nc-AFM/LT-STM, indicating the potential use of this technique to study other intermolecular bonds and to understand complex supramolecular assemblies at the atomic/sub-molecular level.

Effect of LRRK2 protein and activity on stimulated cytokines in human monocytes and macrophages.

Leucine-rich-repeat kinase 2 (LRRK2), a potential therapeutic target for the treatment of Parkinson's disease (PD), is highly expressed in monocytes and macrophages and may play a role in the regulation of inflammatory pathways. To determine how LRRK2 protein levels and/or its activity modulate inflammatory cytokine/chemokine levels in human immune cells, isogenic human induced pluripotent stem cells (iPSC) with the LRRK2-activating G2019S mutation, wild-type LRRK2, and iPSC deficient in LRRK2 were differentiated to monocytes and macrophages and stimulated with inflammatory toll-like receptor (TLR) agonists in the presence and absence of LRRK2 kinase inhibitors. The effect of LRRK2 inhibitors and the effect of increasing LRRK2 levels with interferon gamma on TLR-stimulated cytokines were also assessed in primary peripheral blood-derived monocytes. Monocytes and macrophages with the LRRK2 G2019S mutation had significantly higher levels of cytokines and chemokines in tissue culture media following stimulation with TLR agonists compared to isogenic controls. Knockout of LRRK2 impaired phagocytosis but did not significantly affect TLR-mediated cytokine levels. Interferon gamma significantly increased the levels of LRRK2 and phosphorylation of its downstream Rab10 substrate, and potentiated TLR-mediated cytokine levels. LRRK2 kinase inhibitors did not have a major effect on TLR-stimulated cytokine levels. Results suggest that the LRRK2 G2019S mutation may potentiate inflammation following activation of TLRs. However, this was not dependent on LRRK2 kinase activity. Indeed, LRRK2 kinase inhibitors had little effect on TLR-mediated inflammation under the conditions employed in this study.

Atomic Ni and Cu co-anchored 3D nanoporous graphene as an efficient oxygen reduction electrocatalyst for zinc-air batteries.

Highly active, cost-effective and durable electrocatalysts for the oxygen reduction reaction (ORR) are critically important for renewable energy conversion and storage. Here we report a 3D bicontinuous nitrogen doped nanoporous graphene electrocatalyst co-anchoring with atomically dispersed nickel and copper atoms ((Ni,Cu)-NG) as a highly active single-atom ORR catalyst, fabricated by the combination of chemical vapor deposition and high temperature gas transportation. The resultant (Ni,Cu)-NG exhibits an exceptional ORR activity in alkaline electrolytes, comparable to the Pt-based benchmarks, from the synergistic effect of the CuNx and NiNx complexes. Endowed with high catalytic activity and outstanding durability under harsh electrochemical environments, rechargeable zinc-air batteries using (Ni,Cu)-NG as the cathodes show excellent energy efficiency (voltage gap of 0.74 V), large power density (150.6 mW cm-2 at 250 mA cm-2) and high cycling stability (>500 discharge-charge cycles at 10 mA cm-2). This study may pave an efficient avenue for designing highly durable single-atom ORR catalysts for metal-air batteries.

Exploring promising gas sensing and highly active catalysts for CO oxidation: transition-metal (Fe, Co and Ni) adsorbed Janus MoSSe monolayers.

From first-principles calculations, the transition-metal (TM) atom (Fe, Co and Ni) adsorbed Janus MoSSe monolayer, toxic gas molecules (CO, NH3 and H2S) adsorbed on the Ni-MoSSe monolayer and CO catalytic oxidation on the Fe-MoSSe monolayer are systematically investigated. An increasing order (Fe-MoSSe < Co-MoSSe < Ni-MoSSe) is found for the stability and band gap of the TM atom adsorbed Janus MoSSe monolayer. These toxic gas molecules are found to be weakly physisorbed and strongly chemisorbed on the pristine and Ni-MoSSe monolayers, respectively. The electronic structure and gas molecular adsorption properties of the Janus MoSSe monolayer can be modulated by adsorbing different TM atoms and gas molecules. Particularly, the CO catalytic oxidation can be realized on the Fe-MoSSe monolayer in light of the more preferable Eley-Rideal (ER) mechanism with the two-step route (CO + O2 → OOCO → CO2 + Oads, CO + Oads → CO2) with highly exothermic processes in each step. The adsorption of TM atoms which may greatly enhance gas sensing performance and catalytic performance of CO oxidation based on the Janus MoSSe monolayer is further discussed.

Enhancing hydrocarbon production via ex-situ catalytic co-pyrolysis of biomass and high-density polyethylene: Study of synergistic effect and aromatics selectivity.

We conducted ex-situ catalytic fast co-pyrolysis (co-CFP) of corn stalk (CS) and high-density polyethylene (HDPE) over HZSM-5 catalyst to enhance the production of hydrocarbons. The effect of pyrolysis temperature and CS-to-HDPE mass ratio (CS/HDPE) on the yield of condensable volatile organic products (CVOPs) and the relative content of hydrocarbons were studied. The synergisms between CS and HDPE were determined based on the difference between the experimental and theoretical CVOP and hydrocarbons content. The results showed that the addition of HDPE significantly promotes the production of CVOPs, reaching the maximum value at 750 °C. In the presence of HZSM-5, the CVOP and hydrocarbons production, especially aromatics, were enhanced further, and 650 °C and 700 °C were the preferable pyrolysis temperature for desired products. Benzene, toluene, and xylenes were the predominant aromatics during the CFP process due to the good shape-selectivity of HZSM-5, contributing to the highest selectivity of C5-C11 compounds in C5+ hydrocarbons. CS/HDPE mass ratio of 1:1 was a critical point for enhancing aromatics yield. CS/HDPE < 1 was the recommended mass ratio for increasing the relative aromatic hydrocarbons content, which increases as the CS/HDPE mass ratio decreases. Meanwhile, we presented the potential reaction pathways between CS and HDPE to explain the synergistic effects during the co-CFP process.

Odd-even alternations in helical propensity of a homologous series of hydrocarbons.

Odd and even homologues of some n-alkane-based systems are known to exhibit notably different trends in solid-state properties; a well-known illustration is the zigzag plot of their melting point versus chain length. Odd-even effects in the solid state often arise from intermolecular interactions that involve fully extended molecules. These effects have also been observed in less condensed phases, such as self-assembled monolayers; however, the origins of these effects in such systems can be difficult to determine. Here we combined NMR and computational analysis to show that all-syn contiguously methyl-substituted hydrocarbons, with chain lengths from C6 to C11, exhibit a dramatic odd-even effect in helical propensity. The even- and odd-numbered hydrocarbons populate regular and less-controlled helical conformations, respectively. This knowledge will guide the design of helical hydrocarbons as rigid scaffolds or as hydrophobic components in soft materials.

Conditioned Medium Enhances Osteogenic Differentiation of Induced Pluripotent Stem Cell-Derived Mesenchymal Stem Cells.

Background: Recent studies have shown that induced pluripotent stem cells (iPSCs) could be differentiated into mesenchymal stem cells (MSCs) with notable advantages over iPSCs per se. In order to promote the application of iPSC-MSCs for osteoregenerative medicine, the present study aimed to assess the ability of murine iPSC-MSCs to differentiate into osteoblast phenotype. Methods: Osteogenic differentiation medium, blending mouse osteoblast-conditioned medium (CM) with basic medium (BM) at ratio 3:7, 5:5 and 7:3, were administered to iPSC-MSCs, respectively. After 14 days, differentiation was evaluated by lineage-specific morphology, histological stain, quantitative reverse transcription-polymerase chain reaction and immunostaining. Results: The osteogenesis-related genes, alp, runx2, col1 and ocn expressions suggest that culture medium consisting of CM:BM at the ratio of 3:7 enhanced the osteogenic differentiation more than other concentrations that were tested. In addition, the alkaline phosphatase activity and osteogenic marker Runx2 expression demonstrate that the combination of CM and BM significantly enhanced the osteogenic differentiation of iPSC-MSCs. Conclusion: In summary, this study has shown that osteoblast-derived CM can dramatically enhance osteogenic differentiation of iPSC-MSCs toward osteoblasts. Results from this work will contribute to optimize the osteogenic induction conditions of iPSC-MSCs and will assist in the potential application of iPSC-MSCs for bone tissue engineering.

DFT calculations of the defect structures, electronic structures, and EPR parameters for three Rh2+ centers in AgCl.

The local structures for various Rh2+ centers in AgCl are theoretically studied using density functional theory (DFT) with periodic CP2K program. Through geometry optimizing, the stable ground states with minimal energies and electronic structures are obtained for the tetragonally elongated (TE ), orthorhombically elongated (OE ), and tetragonally compressed (TC ) centers, and the corresponding g and hyperfine coupling tensors are calculated in ORCA level. The calculations reveal obvious Jahn-Teller elongation distortions of about 0.109 and 0.110 Å along [001] axis for TE and OE centers without and with 1 next nearest neighbor (nnn) cation vacancy VAg in [100] axis, respectively. Whereas TC center with 1 nnn VAg along [001] axis exhibits moderate axial compression of about 0.066 Å due to the Jahn-Teller effect. For OE and TC centers with 1 nnn VAg , the ligand intervening in the central Rh2+ and the VAg is found to displace away from the VAg by about 0.028 and 0.024 Å, respectively. The present results are discussed and compared with those of the previous calculations based on the perturbation formulas by using the improved ligand field theory.

Synergy of synthesis, computation and NMR reveals correct baulamycin structures.

Small-molecule, biologically active natural products continue to be our most rewarding source of, and inspiration for, new medicines. Sometimes we happen upon such molecules in minute quantities in unique, difficult-to-reach, and often fleeting environments, perhaps never to be discovered again. In these cases, determining the structure of a molecule-including assigning its relative and absolute configurations-is paramount, enabling one to understand its biological activity. Molecules that comprise stereochemically complex acyclic and conformationally flexible carbon chains make such a task extremely challenging. The baulamycins (A and B) serve as a contemporary example. Isolated in small quantities and shown to have promising antimicrobial activity, the structure of the conformationally flexible molecules was determined largely through J-based configurational analysis, but has been found to be incorrect. Our subsequent campaign to identify the true structures of the baulamycins has revealed a powerful method for the rapid structural elucidation of such molecules. Specifically, the prediction of nuclear magnetic resonance (NMR) parameters through density functional theory-combined with an efficient sequence of boron-based synthetic transformations, which allowed an encoded (labelled) mixture of natural-product diastereomers to be prepared-enabled us rapidly to pinpoint and synthesize the correct structures.