Design, Synthesis, and Mechanism of Novel 9‑Aliphatic Amine Tryptanthrin Derivatives against Phytopathogenic Bacteria

Taking inspiration from the use of natural product-derived bactericide candidates in drug discovery, a series of novel 9-aliphatic amine tryptanthrin derivatives were designed, synthesized, and evaluated for their biological activity against three plant bacteria. The majority of these compounds exhibited excellent antibacterial activity in vitro. Compound 7c exhibited a significantly superior bacteriostatic effect against Xanthomonas axonopodis pv Citri (Xac), Xanthomonas oryzae pv Oryzae (Xoo), and Pseudomonas syringae pv Actinidiae (Psa) with final corrected EC50 values of 0.769, 1.29, and 15.5 μg/mL, respectively, compared to the commercial pesticide thiodiazole copper which had EC50 values of 58.8, 70.9, and 91.9 μg/mL. Preliminary mechanism studies have demonstrated that 7c is capable of altering bacterial morphology, inducing reactive oxygen species accumulation, promoting bacterial cell apoptosis, inhibiting normal cell growth, and affecting cell membrane permeability. Moreover, in vivo experiments have substantiated the effectiveness of 7c as a therapeutic and defensive agent against the citrus canker. The proteomic analysis has unveiled that the major disparities are located within the bacterial secretion system pathway, which hinders membrane transportation. These discoveries imply that 7c could be an auspicious prototype for developing antiphytopathogenic bacterial agents

Thermal/Water-Induced Phase Transformation and Photoluminescence of Hybrid Manganese(II)-Based Chloride Single Crystals

Mn(II)-based hybrid halides have attracted great attention from the optoelectronic fields due to their nontoxicity, special luminescent properties, and structural diversity. Here, two novel organic–inorganic hybrid Mn(II)-based halide single crystals (1-mpip)MnCl4·3H2O and (1-mpip)2MnCl6 (1-mpip = 1-methylpiperazinium, C5H14N2+) were grown by a slow evaporation method in ambient atmosphere. Interestingly, (1-mpip)2MnCl6 single crystals exhibit the green emission with a PL peak at 522 nm and photoluminescence quantum yields (PLQYs) of ≈5.4%, whereas (1-mpip)MnCl4·3H2O single crystals exhibit no emission characteristics. More importantly, there exists a thermal-induced phase transformation from (1-mpip)MnCl4·3H2O to emissive (1-mpip)2MnCl6 at 372 K. Moreover, a reversible luminescent conversion between (1-mpip)MnCl4·3H2O and (1-mpip)2MnCl6 was simply achieved when heated to 383 K and placed in a humid environment or sprayed with water. This work not only deepens the understanding of the thermal-induced phase transformation and humidity-sensitive luminescent conversion of hybrid Mn(II)-based halides, but also provides a guidance for thermal and humidity sensing and anticounterfeiting applications of these hybrid materials

Supplementary document for Single-frequency DBR lasing by monolithic cavity design in germanium-free photosensitive highly Yb3+-doped silica fiber - 6947424.pdf

Photosensitivity comparison between Ce doped fiber and Ge doped fibe

Real-Time Sensing of TET2-Mediated DNA Demethylation In Vitro by Metal–Organic Framework-Based Oxygen Sensor for Mechanism Analysis and Stem-Cell Behavior Prediction

Active DNA demethylation, mediated by O₂-dependent ten–eleven translocation (TET) enzymes, has essential roles in regulating gene expression. TET kinetics assay is vital for revealing mechanisms of demethylation process. Here, by a metal–organic framework (MOF)-based optical O₂ sensor, we present the first demonstration on real-time TET2 kinetics assay in vitro. A series of luminescent Cu­(I) dialkyl-1,2,4-triazolate MOFs were synthesized, which were noble-metal-free and able to intuitively response to dissolved O₂ in a wide range from cellular hypoxia (≤15 μM) to ambient condition (∼257 μM). By further immobilization of the MOFs onto transparent silicon rubber (MOF@SR) to construct O₂ film sensors, and real-time monitoring of O₂ consumption on MOF@SR over the reaction time, the complete TET2-mediated 5-methylcytosine (5mC) oxidation process were achieved. The method overcomes the limitations of the current off-line methods by considerably shortening the analytical time from 0.5–18 h to 10 min, and remarkably reducing the relative standard deviation from 10%–68% to 0.68%–4.2%. As a result, the Michaelis–Menten constant (<i>K</i>_m) values of TET2 for 5mC and O₂ in ascorbic acid-free (AA^–) condition were precisely evaluated to be 24 ± 1 and 43.8 ± 0.3 μM, respectively. By comparative study on AA-containing (AA⁺) conditions, and further establishing kinetics models, the stem-cell behavior of TETs was successfully predicted, and the effects of key factors (AA, O₂, Fe²⁺) on TETs were revealed, which were fully verified in mouse embryonic stem (mES) cells. The method is promising in wide application in kinetics analysis and cell behavior prediction of other important O₂-related enzymes