An unprecedented HS release from cysteine esters and amides (CysO/NHR) under physiological conditions was discovered and the plausible mechanism was proposed. Alkylation of the amino moiety of cysteine esters enables the HS release to be tuned and further provides support to the mechanistic insights. This discovery not only provides new insights into several fundamental science issues including non-enzymatic HS-produced pathways, but also inspires new tunable cleavable motifs for sustained release of arylthiols and even for prodrug design.
View Article and Find Full Text PDFThe importance of selenium (Se) in biology and health has become increasingly clear. Hydrogen selenide (HSe), the biologically available and active form of Se, is suggested to be an emerging nitric oxide (NO)-like signaling molecule Nevertheless, the research on HSe chemical biology has technique difficulties due to the lack of well-characterized and controllable HSe donors under physiological conditions, as well as a robust assay for direct HSe quantification. Motivated by these needs, here, we demonstrate that selenocyclopropenones and selenoamides are tunable donor motifs that release HSe upon reaction with cysteine (Cys) at pH 7.
View Article and Find Full Text PDFHS is a well-known toxic gas and also a gaseous signaling molecule involved in many biological processes. Advanced chemical tools that can regulate HS levels are useful for understanding HS biology as well as its potential therapeutic effects. To this end, we have developed a series of 7-nitro-1,2,3-benzoxadiazole (NBD) amines as potential HS scavengers.
View Article and Find Full Text PDFCompounds with a nitrobenzoxadiazole (NBD) skeleton exhibit prominent useful properties including environmental sensitivity, high reactivity toward amines and biothiols (including H2S) accompanied by distinct colorimetric and fluorescent changes, fluorescence-quenching ability, and small size, all of which facilitate biomolecular sensing and self-assembly. Amines are important biological nucleophiles, and the unique activity of NBD ethers with amines has allowed for site-specific protein labelling and for the detection of enzyme activities. Both H2S and biothiols are involved in a wide range of physiological processes in mammals, and misregulation of these small molecules is associated with numerous diseases including cancers.
View Article and Find Full Text PDFThe development of advanced bioorthogonal reactions for detection and labeling of biomolecules is significant in chemical biology. Recently, researchers have found that multifluorinated aryl azides hold great potential for the development of improved bioorthogonal reactions. The fluorine atom can be a perfect substituent group because of its properties of excellent electronegativity and small steric hindrance.
View Article and Find Full Text PDFThe combined usage of two bioorthogonal reactions can provide hetero-bifunctional molecules under physiological conditions for various applications. Based on the Nonhydrolysis Staudinger Reaction (NSR), we design and develop a bisazido linker 1 for chemoselective dual-functionalization without the need of protection using catalyst-free and one-pot procedures. The NSR is much faster with tetrafluorinated aromatic azide than that the Staudinger-Bertozzi or SPAAC ligation with alkyl azide, as revealed by HPLC analysis and fluorescence kinetics.
View Article and Find Full Text PDFThe development of efficient bioorthogonal reactions for sensing of endogenous biomolecules and for bioconjugation should be of paramount importance in the field of chemical biology. In this work, the o,o'-difluorinated aromatic azide was firstly employed to develop a new fast-response fluorescent probe 1 for HS detection and for bioorthogonal reactions. Compared with non- and mono-fluorinated probes, 1 showed faster reaction toward HS, the third gasotransmitter, in buffer (pH 7.
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