A pyrene-based ratiometric fluorescent probe with a large Stokes shift for selective detection of hydrogen peroxide in living cells

Hydrogen peroxide(H2O2)plays a significant role in regulating a variety of biological processes.Dysregulation of H2O2 can lead to various diseases.Although numerous fluorescent imaging probes for H2O2 have been reported,the development of H2O2 ratiometric fluorescent probe with large Stokes shift remains rather limited.Such probes have shown distinct advantages,such as minimized interference from environment and improved signal-to noise ratio.In this work,we reported a new pyrene-based compound Py-VPB as H2O2 fluorescent probe in vitro.The probe demonstrated ratiometric detection behavior,large Stokes shift and large emission shift.In addition,the probe showed high sensitivity and selectivity towards H2O2 in vitro.Based on these excellent properties,we successfully applied Py-VPB to the visualization of exogenous and endogenous H2O2 in living cells.Cell imaging study also showed that our probe was localized in the mitochondria.We envision that the probe can provide a useful tool for unmasking the biological roles of mitochondrial H2O2 in living systems.

Contemporary synthesis of bioactive cyclobutane natural products

Many cyclobutane natural products have intriguing biological properties that arise from their fascinating chemical structures.Cyclobutane natural products feature a cyclobutane scaffold as the core or as a part of the spirocyclic or fused cyclic core.However,the highly functionalized nature and the inherent stereochemistry of these cyclobutane natural products,which are associated with their biological activities,pose tremendous challenges to their preparation.In this perspective,we present contemporary advancements in synthetic methods and/or strategies en route to the bioactive cyclobutane natural products.We begin by describing the representative bioactive cyclobutane natural products and then focus on illustrative examples of their syntheses reported from 2018 to 2021.These advances will enable efficient syntheses of cyclobutanes of structural and biological importance.

“人民科学家”叶渚沛——纪念叶渚沛先生诞辰120周年

中国科学院院士、中国科学院化工冶金研究所创始人叶渚沛(1902-1971)先生,是享誉世界的冶金学家,是我国化工冶金学科的先驱者和奠基人,是一位伟大的爱国者,曾任第三届全国人民代表大会常务委员会委员。叶渚沛先生率先在我国倡导和组织开拓了氧气转炉炼钢技术,为我国钢铁工业的发展写下了光辉的一页;他标新立异,提出了强化高炉冶炼的“三高一喷”基本理论,并指导实施,使我国高炉生产技术的水平达到世界前列.

A dual-function chemical probe for detecting erasers of lysine lipoylation

Lysine lipoylation plays vital roles in cell metabolism and redox processes.For example,removal of lipoylation will decrease pyruvate dehydrogenase activity and affect the citric acid cycle.Despite the important functions of lysine lipoylation,the mechanisms for the addition and removal of this modification remain largely unexplored.Very few useful chemical tools are available to study the interactions of lysine lipoylation with its regulatory delipoylation proteins.For example,immunoaffinity purification-mass spectrometry is one of such tools,which highly relies on antibody efficiency and purification techniques.Single-step activity based fluorogenic probes developed by our groups and others is also an efficient method to study the deacylation activity.Affinitybased labeling probe using photo-cross-linker is a powerful platform to study the transient and dynamic interactions of peptide ligands with the interacting proteins.Herein,we have designed and synthesized a dual-function probe KTLlip for studying enzymatic delipoylation(eraser)activity and interaction of lysine lipoylation with the eraser at the same time.We show that KTLlip can be used as a useful tool to detect delipoylation as demonstrated by its ability to fluorescently label the eraser activity of recombinant Sirt2.We envision that the probe will help delineate the roles of delipoylation enzyme in biology.

A reversible microarray immobilization strategy based on thiol-quinone reaction

Microarray technology has been widely applied in biomedical research.The key to microarray study is to develop efficient immobilization method.In this study,we designed a new reversible microarray immobilization method based on thiol-quinone reaction.A quinone-functionalized slide was fabricated through H_(2)O_(2)treatment of dopamine-coated slides.Various thiol-containing molecules can be anchored onto the quinone-functionalized slides via thioether linker,which could be cleaved under H_(2)O_(2) treatment to regenerate quinone groups on the surface.The highly versatile approach can be widely used for immobilization of various thiol-containing molecules.