Synthesis of sterically hindered 3,5,5-trimethyl 2,6-dioxo tetrahydro pyrimidine as HCV protease inhibitors

An efficient route for the synthesis of sterically hindered substituted and unsubstituted 2,6-dioxo tetrahydropyrimidines from amine 1 is described. These analogs are active against HCV NS3 serine protease. The biological data for some of the representative examples are also reported.     

Dual reactivity disulfide bridging reagents; enabling new approaches to antibody fragment bioconjugation

Disulfide bridging, also known as disulfide stapling, is a powerful strategy for the construction of site-selective protein bioconjugates. Here we describe the first examples of a new class of such reagents, containing a ‘stable-labile’ design. These dual-reactive reagents are designed to form a stable bond to one cysteine and a labile bond to the second; resulting in a robust attachment to the protein with one end of the bridge, whilst the other end serves as a reactive handle for subsequent bioconjugation. By incorporating thioesters into these bridges, we demonstrate that they are primed for native chemical ligation (NCL) with N-terminal cysteines; offering an alternative to the requirement for C-terminal thioesters for use in such ligations. Alternatively, the use of hydrazine as the ligating nucleophile enables a separate cargo to be attached to each cysteine residue, which are exploited to insert variably cleavable linkers. These methodologies are demonstrated on an antibody fragment, and serve to expand the scope of disulfide bridging strategies whilst offering a convenient route to the construction of multifunctional antibody fragment conjugates.

Here we describe the first examples of a new class of disulfide bridging reagents, designed to insert a ‘stable-labile’ linkage; which can then be exploited to generate dual functional antibody fragment conjugates.     

Transitions of Collective Motions Driven by Phase Resetting

The front cover artwork is provided by Prof. Gao's group. The image shows the motion patterns transition of the active gel group under the step light intensity, which describes the mechanism of a new collective emergence structure. Read the full text of the Research Article at 10.1002/cphc.202300054 .