Novel Synthesis of IMC-48 and Affinity Evaluation with Different i-Motif DNA Sequences

During the last decade, the evidence for the biological relevance of i-motif DNA (i-DNA) has been accumulated. However, relatively few molecules were reported to interact with i-DNA, and a controversy concerning their binding mode, affinity, and selectivity persists in the literature. In this context, the cholestane derivative IMC-48 has been reported to modulate bcl-2 gene expression by stabilizing an i-motif structure in its promoter. In the present contribution, we report on a novel, more straightforward, synthesis of IMC-48 requiring fewer steps compared to the previous approach. Furthermore, the interaction of IMC-48 with four different i-motif DNA sequences was thoroughly investigated by bio-layer interferometry (BLI) and circular dichroism (CD) spectroscopy. Surprisingly, our results show that IMC-48 is a very weak ligand of i-DNA as no quantifiable interaction or significant stabilization of i-motif structures could be observed, stimulating a quest for an alternative mechanism of its biological activity.

Mild, efficient, and environmentally friendly synthesis of symmetrical N,N′-alkylidenebisamides under solvent-free conditions catalyzed by H7[(P2W17O61)FeIII(H2O)]

H₇[(P₂W₁₇O₆₁)Fe^III(H₂O)] is introduced as an effective catalyst for the one-pot synthesis ofN,N′-alkylidenebisamides. The catalyst could be easily separated without noticeable reduction in activity.

Silica-supported barium chloride (SiO2–BaCl2) — Efficient and heterogeneous catalyst for the environmentally friendly preparation of N,N′-alkylidene bisamides under solvent-free conditions

A series of N,N′-alkylidene bisamides were prepared via a green and environmentally friendly synthetic protocol from the reaction of phenyl acetylene or hex-1-yne, aromatic aldehyde, and benzamide or acetamide. Silica-supported barium chloride (SiO2–BaCl2) catalyzes the process of the reaction. The prepared catalysts were characterized by X-ray diffraction, and the products were obtained with high conversions and yields.