Tung-Kung Wu

To investigate the manipulations of light on distinct vibration‐induced emission (VIE) behaviors, the classic VIE‐fluorophore 9,14‐diphenyl‐9,14‐dihydrodibenzo[ a,c ]phenazine (DPAC) was integrated with an optical switchable stiff‐stilbene moiety into the first molecular design of various sized nanohoop structures (i.e., RnD , where n = 4 and 6 with different cavities). The goal is to exploit tunable nano‐twisted structures of novel geometric macrocycle isomers, controlled by cis/trans isomerizations of stiff‐stilbene units under 320/385 nm light irradiations, to modulate corresponding bent and planar configurational structures of DPAC moieties and adjust their ratiometric (photoluminescence) PL emissions. Light‐controllable cis/trans isomerizations of different sized nanohoop structures resulted in distinct emission changes due to adaptable structural constraints, facilitating alterations of PL emission colors with significant Stokes shifts. The emission spectra spanned from cyan/white/orange‐light emissions, triggered by cis/trans isomerizations of stiff‐stilbene units upon respective light exposures of 320/385 nm. Additionally, external factors such as solvent polarities, viscosities, temperatures, and water contents could further regulate ratiometric emission features of DPAC‐based geometric macrocycle isomers, demonstrating high sensitivities toward various environmental changes. This study highlighted the potentials for developing multi‐color emissive smart materials by utilizing nano‐twisting of DPAC‐based nanohoop structures tuned by optical switchable moieties, opening new avenues for innovative applications in stimuli‐responsive materials.

Grimontia hollisae thermostable direct hemolysin (Gh-TDH) is a pore-forming toxin that disrupts the cell membrane, leading to erythrocyte lysis and cytotoxicity. Previous studies showed that fluorescently labeled Gh-TDH-FITC binds to hepatocyte membranes and subsequently translocates to the nucleus. Here, we demonstrate for the first time that Gh-TDH cleaves DNA with 3′–5′ nuclease activity. The crystal structure of Gh-TDH in complex with ssDNA unveils a unique DNA-binding configuration. Notably, the putative cleavage site (Tyr87-Lys88-Asp89) deviates from the canonical 3′–5′ exonuclease motif (Asp-Glu-Asp-Asp). Site-directed mutagenesis and binding kinetics assays demonstrate that Lys88 is essential for nuclease activity, supporting its central role in catalysis. TDH homologues are widespread in Vibrio, with DNA-binding and catalytic residues highly conserved. Consistently, V. parahaemolyticus TDH also exhibits 3′–5′ exonuclease activity, indicating this nuclease function is an intrinsic, conserved feature of the TDH family rather than incidental. These findings provide the structural basis and mechanism of DNA binding and cleavage by Gh-TDH. Gh-TDH is thus the first Vibrio pore-forming toxin shown to have dual hemolytic and nuclease activities. This work opens new avenues to explore why Vibrio pore-forming toxins have evolved nuclease activity and what physiological or pathogenic roles it may play in vivo.

Background: Enhanced Recovery After Surgery (ERAS) programmes improve perioperative outcomes, but real-world adherence varies widely across institutions, limiting their effectiveness. Disease-Specific Care Certification (DSCC) provides governance and standardisation but lacks operational mechanisms for frontline implementation. This study evaluates an integrated Quality Control Circle (QCC) model aligned with DSCC and ERAS protocols to improve perioperative reliability and patient-centred outcomes in joint replacement. Methods: A pre–post quasi-experimental study was conducted involving 515 patients undergoing elective total joint replacement. A multidisciplinary QCC team employed root-cause analysis, Pareto prioritisation and iterative Plan–Do–Study–Act cycles to refine processes. DSCC governance principles were used to structure standardised pathways, unify documentation and reinforce interdisciplinary communication. Outcomes included ERAS compliance, length of stay (LOS), preoperative discomfort (thirst, dry mouth), unnecessary blood preparation, complications and staff competency. Results: ERAS compliance increased from 80.9% to 100% after implementation. Preoperative thirst (p=0.0156) and dry mouth scores (p=0.0073) improved significantly. LOS decreased from 6.63 to 5.98 days. Unnecessary blood preparation was reduced from 237 units to zero. Staff competency improved across all domains. No increase in postoperative complications or readmissions was observed. Conclusions: Integration of QCC operational tools, DSCC governance and ERAS clinical elements yielded substantial improvements in perioperative reliability, efficiency and patient comfort. The QCC–DSCC–ERAS hybrid model is feasible, scalable and potentially generalisable to other institutions seeking high-reliability perioperative care.

Aromatase inhibitors (AIs) are vital in the treatment of estrogen‐dependent breast cancer, especially in postmenopausal women. In this study, a series of steroidal glycosides (SGs) derived from trans ‐androsterone ( t AND), estrone (E1), and estradiol (E2) were synthesized using a one‐pot multi‐enzyme glycosylation approach and structurally characterized via HPLC, MS, and NMR. Among the synthesized compounds, E1‐α‐2DG ( 2b ) and E2‐α‐2DG ( 3b ) demonstrated the most potent aromatase inhibition, with IC ₅₀ values of 0.101 ± 0.001 μM and 0.159 ± 0.009 μM, respectively. Molecular docking revealed that these glycosides form key hydrogen bonds with catalytic residues and the heme group of CYP19A1. In vitro cytotoxicity showed that E1‐α‐2DG selectively inhibited the growth of MCF‐7 and MDA‐MB‐231 breast cancer cells in a dose‐dependent manner, with the highest potency observed against triple‐negative MDA‐MB‐231 cells (IC ₅₀ = 20.46 ± 2.92 μM), while exhibiting no toxicity toward non‐cancerous HEK293 cells. These findings suggest that glycosylation enhances the pharmacological potential of steroidal scaffolds and highlights E1‐α‐2DG as a promising lead compound for the development of safer, dual‐function breast cancer therapies.

Enzymatically glycosylated 18β-glycyrrhetinic acid derivatives potently inhibit SARS-CoV-2 M^pro, with enhanced solubility and unique sugar-driving binding, highlighting their potential as cost-effective antiviral candidates.

This report presents the design and synthesis of quinazolinone-based derivatives as promising SARS-CoV-2 3CL protease inhibitors. Two novel series, namely, febrifugine analogues 4a–i and quinazolinone conjugated benzimidazoles 9a–c, were successfully synthesized starting from isatoic anhydride. The synthesized quinazolinone derivatives were evaluated for their cytotoxicity against cancer cell lines and SARS-CoV-2 3CL inhibitory activity. The results showed that the synthesized compounds did not have significant toxicity for the non-cancer HEK293 cell line and MCF-7, MDA-MB-231, HEPG2 and HEPG2.2.15 cancer cell lines. Notably, compound 9b exhibited anti-3CL enzymatic activity in a dose-dependent manner, with the calculated IC₅₀ value of 10.73 ± 1.17 μM. Docking results highlighted the interaction between 9b and 3CL protease through hydrogen bonding with key amino acids, including His41, Met49, Cys145, Met165, Arg188, His164, and Glu166, at the active site of the protease. Pharmacokinetic studies and ADME analyses provide valuable insights into the potential of compound 9b as a drug candidate. These findings support the new scaffold as a candidate for 3CL^pro inhibition and advanced anti-coronavirus drug research.

The severe acute respiratory syndrome coronavirus 2 main protease (SARS-CoV-2-M^pro) plays an essential role in viral replication, transcription, maturation, and entry into host cells. Furthermore, its cleavage specificity for viruses, but not humans, makes it a promising drug target for the treatment of coronavirus disease 2019 (COVID-19). In this study, a fragment-based strategy including potential antiviral quinazolinone moiety and glutamine- or glutamate-derived peptidomimetic backbone and positioned nitro functional groups was used to synthesize putative M^pro inhibitors. Two compounds, G1 and G4, exhibited anti-M^pro enzymatic activity in a dose-dependent manner, with the calculated IC₅₀ values of 22.47 ± 8.93 μM and 24.04 ± 0.67 μM, respectively. The bio-layer interferometer measured real-time binding. The dissociation kinetics of G1/M^pro and G4/M^pro also showed similar equilibrium dissociation constants (K_D) of 2.60 × 10⁻⁵ M and 2.55 × 10⁻⁵ M, respectively, but exhibited distinct association/dissociation curves. Molecular docking of the two compounds revealed a similar binding cavity to the well-known M^pro inhibitor GC376, supporting a structure−function relationship. These findings may open a new avenue for developing new scaffolds for M^pro inhibition and advance anti-coronavirus drug research.

Capreomycin (CMN) is an important second-line antituberculosis antibiotic isolated from Saccharothrix mutabilis subspecies capreolus. The gene cluster for CMN biosynthesis has been identified and sequenced, wherein the cph gene was annotated as a phosphotransferase likely engaging in self-resistance. Previous studies reported that Cph inactivates two CMNs, CMN IA and IIA, by phosphorylation. We, herein, report that (1) Escherichia coli harboring the cph gene becomes resistant to both CMN IIA and IIB, (2) phylogenetic analysis regroups Cph to a new clade in the phosphotransferase protein family, (3) Cph shares a three-dimensional structure akin to the aminoglycoside phosphotransferases with a high binding affinity (K_D) to both CMN IIA and IIB at micromolar levels, and (4) Cph utilizes either ATP or GTP as a phosphate group donor transferring its γ-phosphate to the hydroxyl group of CMN IIA. Until now, Cph and Vph (viomycin phosphotransferase) are the only two known enzymes inactivating peptide-based antibiotics through phosphorylation. Our biochemical characterization and structural determination conclude that Cph confers the gene-carrying species resistance to CMN by means of either chemical modification or physical sequestration, a naturally manifested belt and braces strategy. These findings add a new chapter into the self-resistance of bioactive natural products, which is often overlooked while designing new bioactive molecules.