Dioxaphosphorinane-constrained nucleic Acid dinucleotides as tools for structural tuning of nucleic acids.

We describe a rational approach devoted to modulate the sugar-phosphate backbone geometry of nucleic acids. Constraints were generated by connecting one oxygen of the phosphate group to a carbon of the sugar moiety. The so-called dioxaphosphorinane rings were introduced at key positions along the sugar-phosphate backbone allowing the control of the six-torsion angles α to ζ defining the polymer structure.

Synthesis and antiplasmodial activity of streptocyanine/peroxide and streptocyanine/4-aminoquinoline hybrid dyes.

Two series of streptocyanine dyes incorporating cyclic peroxide or 4-aminoquinoline moieties are prepared and X-ray diffraction structures for three compounds are determined. All hybrid dyes show good antiplasmodial activity (0.06 to 0.

New potent bisubstrate inhibitors of histone acetyltransferase p300: design, synthesis and biological evaluation.

Bisubstrate-type compound Lys-CoA has been shown to inhibit the p300 histone acetyl transferase activity efficiently and may constitute a lead compound for a novel class of anticancer therapeutics. Based on this strategy, we synthesized a series of CoA derivatives and evaluated these molecules for their activity as p300 histone acetyltransferases inhibitor. The best activity was obtained with compound 3 bearing a C-5 spacing linker that connects the CoA moiety to a tert-butyloxycarbonyl (Boc) group.

Superoxide-induced bleaching of streptocyanine dyes: Application to assay the enzymatic activity of superoxide dismutases.

With the aim of developing a novel superoxide dismutase (SOD) activity assay, a series of polymethinium salts (streptocyanines) were prepared and studied for their ability to be reduced by superoxide radical anion generated either from the pyrogallol autoxidation or by the xanthine oxidase-catalyzed oxidation of xanthine. The nonacarbon chain streptocyanine 9Cl(NEt(2))(2) was found to be relatively stable in neutral buffered aqueous solutions, to be reduced at a significant rate by superoxide, and addition of iron-dependent superoxide dismutase (Fe-SOD) prevented its bleaching, thus constituting a good candidate as a possible superoxide indicator in a spectrophotometric SOD assay. The values found to be optimal for a SOD assay were defined as pH 7.

Synthesis and antimalarial properties of streptocyanine dyes.

Several streptocyanine dyes were synthesized that contain polymethine chains of varying length. Their in vitro antimalarial activities were evaluated against the virulent P. falciparum parasite.