Comprehensive study of flusulfinam in paddy water-sediment microcosms: Enantioselective fate, degradation pathways, and toxicity assessment.

Flusulfinam, a novel chiral herbicide, demonstrates effective weed control in paddy fields. Nevertheless, a comprehensive investigation into its environmental fate in paddy systems, particularly at the enantiomeric level, remains deficient. Herein, paddy water-sediment microcosms were constructed across four sites to explore the enantiomeric behavior of flusulfinam.

Bridgehead Alkene-Enabled Strain-Driven Bioorthogonal Reaction.

Herein, we report a novel bioorthogonal reaction that hinges on a bridgehead alkene (BHA)-enabled inverse-electron-demand Diels-Alder (IEDDA) cycloaddition. Readily accessible from natural product β-caryophyllene, the strained BHA displays high reactivity toward the IEDDA reaction while maintaining excellent biocompatibility. The developed IEDDA reaction has been applied to protein labeling and pretargeted live cell imaging.

Chemical trigger-enabled bioconjugation reaction.

Development of conceptually novel and practically useful bioconjugation reactions has been an intense pursuit of chemical biology research. Herein, we report an unprecedented bioconjugation reaction that hinges on a chemical trigger-enabled inverse-electron-demand Diels-Alder (IEDDA) cycloaddition of -cycloheptene (TCH) with tetrazine. Unlike the conventional strain-promoted bioconjugation reactions that utilize built-in strained alkenes as reactants, the current one features a "trigger-release-conjugate" reaction model, in which a highly strained TCH species is released from a bench-stable bicyclic -nitrosourea (BNU) derivative upon treatment with an external stimulus.

Nature-Inspired Bioorthogonal Reaction: Development of β-Caryophyllene as a Chemical Reporter in Tetrazine Ligation.

A nature-inspired bioorthogonal reaction has been developed, hinging on an inverse-electron-demand Diels-Alder reaction of tetrazine with β-caryophyllene. Readily accessible from the cheap starting material through a scalable synthesis, the newly developed β-caryophyllene chemical reporter displays appealing reaction kinetics and excellent biocompatibility, which renders it applicable to both in vitro protein labeling and live cell imaging. Moreover, it can be used orthogonally to the strain-promoted alkyne-azide cycloaddition for dual protein labeling.