Bisindolyl Maleimides and Indolylmaleimide Derivatives-A Review of Their Synthesis and Bioactivity

The evolution of bisindolyl maleimides and indolyl maleimide derivatives and their unique biological activities have stimulated great interest in medicinal chemistry programs. Bisindolylmaleimide (BIM)-type compounds arise from natural sources such as arcyriarubin and are biosynthetically related to indolocarbazoles. BIMs are commonly the immediate synthetic precursors of indolocarbazoles, lacking a central bond between the two aromatic units and making them more flexible and drug-like. Synthetic endeavours within this class of compounds are broad and have led to the development of both remarkably potent and selective protein kinase inhibitors. Clinical BIM examples include ruboxistaurin and enzastaurin, which are highly active inhibitors of protein kinase C-β. While BIMs are widely recognised as protein kinase inhibitors, other modes of activity have been reported, including the inhibition of calcium signalling and antimicrobial activity. Critically, structural differences can be used to exploit new bioactivity and therefore it is imperative to discover new chemical entities to address new targets. BIMs can be highly functionalised or chemically manipulated, which provides the opportunity to generate new derivatives with unique biological profiles. This review will collate new synthetic approaches to BIM-type compounds and their associated bioactivities with a focus on clinical applications.

A sulfonyl hydrazone cholesterol conjugate: gelation, anion interaction and its application in dye adsorption

Cholesterol appended sulfonyl-hydrazone derivative 1 was designed and synthesized as a supramolecular gelator for anionic sensing and dye adsorption. Gelator 1 forms a strong gel in DMSO–H₂O and the morphology of the xerogel shows a tiny rod-like fibrous network. The gel of 1 shows a selective response toward CN⁻ and F⁻ ions causing gel-to-sol transformation. The gel of 1 acts as an efficient matrix for adsorption and removal of anionic dyes such as erythrosine B and uranine from water.

Diarylmaleimide-based branched oligomers: strong full-color emission in both solution and solid films

An effective design method is presented to construct highly efficient fluorescent materials in both solution and solid films, by non-conjugately linking fluorophores into branched oligomers. Surface aryl groups are changed to tune the luminescent color from blue (λ_em = 480 nm) to red (λ_em = 651 nm), and realize full-color emission.