Publications by authors named "Herman Ho Yung Sung"

Metal-organic framework (MOF) is a class of porous materials providing an excellent platform for engineering heterogeneous catalysis. We herein report the design of MOF Zr-PZDB consisting of Zr-clusters and PZDB (PZDB = 4,4'-(phenazine-5,10-diyl)dibenzoate) linkers, which served as the heterogeneous donor catalyst for enhanced electron donor-acceptor (EDA) photoactivation. The high local concentration of dihydrophenazine active centers in Zr-PZDB can promote the EDA interaction, therefore resulting in superior catalytic performance over homogeneous counterparts.

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Article Synopsis
  • Researchers successfully utilized a photoactivated metal-organic framework (MOF), Zr-TPDCS-1, to enable heterogeneous thiol catalysis, marking a novel achievement in the field.
  • The structure of Zr-TPDCS-1 includes Zr clusters and TPDCS linkers, which facilitate multiple organic transformations like borylation and silylation through the generation of thiyl radicals upon light exposure.
  • The process was efficient at a gram scale, demonstrating a high turnover number (≈3880) and allowing for easy product separation, indicating strong potential for practical applications in chemical synthesis.
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The G-quadruplex (G4) forming GGGGCC (G4C2) expanded hexanucleotide repeat (EHR) is the predominant genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Developing selective G4-binding ligands is challenging due to the conformational polymorphism and similarity of G4 structures. We identified three first-in-class marine natural products, chrexanthomycin A (), chrexanthomycin B (), and chrexanthomycin C (), with remarkable bioactivities.

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Two new limonoids, 12-ethoxynimbolinins G and H (compounds 1 and 2), and one known compound, toosendanin (Chuanliansu) (compound 3), were isolated from the bark of Melia toosendan. Their structures were elucidated by spectroscopic analysis and X-ray techniques. The absolute configuration of toosendanin (3) was established by single-crystal X-ray diffraction.

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Podophyllotoxone (1) was isolated from the roots of Dysosma versipellis. The structure was determined by spectroscopic analysis in combination with single-crystal X-ray analysis. The absolute configuration of compound 1 was assigned based on the Flack parameter.

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