Selective G-Quadruplex DNA Recognition by a New Class of Designed Cyanines
作者:Rupesh Nanjunda、Eric Owens、Leah Mickelson、Tyler Dost、Ekaterina Stroeva、Hang Huynh、Markus Germann、Maged Henary、W. Wilson
DOI:10.3390/molecules181113588
日期:——
A variety of cyanines provide versatile and sensitive agents acting as DNA stains and sensors and have been structurally modified to bind in the DNA minor groove in a sequence dependent manner. Similarly, we are developing a new set of cyanines that have been designed to achieve highly selective binding to DNA G-quadruplexes with much weaker binding to DNA duplexes. A systematic set of structurally analogous trimethine cyanines has been synthesized and evaluated for quadruplex targeting. The results reveal that elevated quadruplex binding and specificity are highly sensitive to the polymethine chain length, heterocyclic structure and intrinsic charge of the compound. Biophysical experiments show that the compounds display significant selectivity for quadruplex binding with a higher preference for parallel stranded quadruplexes, such as cMYC. NMR studies revealed the primary binding through an end-stacking mode and SPR studies showed the strongest compounds have primary KD values below 100 nM that are nearly 100-fold weaker for duplexes. The high selectivity of these newly designed trimethine cyanines for quadruplexes as well as their ability to discriminate between different quadruplexes are extremely promising features to develop them as novel probes for targeting quadruplexes in vivo.
quantum yield and molar absorptivity. The aggregation of these cyaninedyes was studied and compared to a similar series of symmetric cyaninedyes. It was determined that the heterocycle has more effect on aggregation than the side chain and a dye with two different heterocycles will aggregate less than a dye with the same heterocycle. The dyes were also investigated for Lipinski Rule violations as their
Discovery of trisubstituted pyrazolines as a novel scaffold for the development of selective phosphodiesterase 5 inhibitors
作者:Mohammad Abdel-Halim、Heather Tinsley、Adam B. Keeton、Mohammed Weam、Noha H. Atta、Mennatallah A. Hammam、Amr Hefnawy、Rolf W. Hartmann、Matthias Engel、Gary A. Piazza、Ashraf H. Abadi
DOI:10.1016/j.bioorg.2020.104322
日期:2020.11
modifications led to new PDE5 inhibitors with approximately 20-fold improved potency to inhibit PDE5 and no COX-2 inhibitory activity compared with celecoxib. PDE isozyme profiling of compound 11 revealed a favorable selectivityprofile. These results suggest that trisubstituted pyrazolines provide a promising scaffold for further chemical optimization to identify novel PDE5 inhibitors with potential for less
A new squaraine fluorophore OCTL14 displays ultrabright optical properties and optimal pharmacokinetics, allowing high contrast and durable near-infraredimaging for fluorescence-guided surgery of ovarian cancer. The primary mechanisms of the tumor targetability of OCTL14 involve its rapid diffusion across tumor vasculature and cellular uptake via organic cation transporters and retention in the lysosome