GBM heterogeneity as a function of variable epidermal growth factor receptor variant III activity.

Abnormal activation of the epidermal growth factor receptor (EGFR) due to a deletion of exons 2-7 of EGFR (EGFRvIII) is a common alteration in glioblastoma (GBM). While this alteration can drive gliomagenesis, tumors harboring EGFRvIII are heterogeneous. To investigate the role for EGFRvIII activation in tumor phenotype we used a neural progenitor cell-based murine model of GBM driven by EGFR signaling and generated tumor progenitor cells with high and low EGFRvIII activation, pEGFRHi and pEGFRLo.

Multilayered nanofibers from stacks of single-molecular thick nanosheets of hexakis(alkoxy)triphenylenes.

Symmetrically substituted hexakis(alkoxy)triphenylene (HAT) derivatives were assembled into single molecular thick 2D nanosheets, which stacked further to give multilayered nanofibers through a convenient solution process. Detailed information on molecular arrangement was unraveled by various imaging techniques and diffraction studies.

Dual selectivity expressed in [2 + 2 + 1] dynamic clipping of unsymmetrical [2]catenanes.

A pi-templated dynamic [2 + 2 + 1] clipping protocol is established for the synthesis of [2]catenanes from two parts dialdehyde, two parts diamine, and one part tetracationic cyclophane. It is further diversified for the selective formation of an unsymmetrical [2]catenane showing great translational selectivity by employing two different dialdehydes in a one-pot reaction. The dual selectivity and the dynamic nature are verified by (1)H NMR spectroscopy, X-ray single-crystal structural studies, and exchange experiments.

Probing donor-acceptor interactions and co-conformational changes in redox active desymmetrized [2]catenanes.

We describe the synthesis and characterization of a series of desymmetrized donor-acceptor [2]catenanes where different donor and acceptor units are assembled within a confined catenated geometry. Remarkable translational selectivity is maintained in all cases, including two fully desymmetrized [2]catenanes where both donors and acceptors are different, as revealed by X-ray crystallography in the solid state, and by (1)H NMR spectroscopy and electrochemistry in solution. In all desymmetrized [2]catenanes the co-conformation is dominated by the strongest donor and acceptor pairs, whose charge-transfer interactions also determine the visible absorption properties.

Linear pi-acceptor-templated dynamic clipping to macrobicycles and [2]rotaxanes.

Cage me! A linear dumbbell-shaped bipyridinium molecule can template cage formation around itself through sixfold imine bond formation to give an interlocked [2]rotaxane as the single product (see picture). This highly efficient [2+3] clipping occurs despite the symmetry mismatch between the template and the formed macrobicycle.

Alternative donor-acceptor stacks from crown ethers and naphthalene diimide derivatives: rapid, selective formation from solution and solid state grinding.

The atypical 1:2 complexation between an electron-rich crown ether host and electron-deficient naphthalene diimide-based guests led to the formation of alternative donor-acceptor (ADA) stacks. The ADA stacks can be expediently obtained in high yield as polycrystalline aggregates from solution. More remarkably, the high degree of organization has also been realized in a simple solid-to-solid mechanical grinding process.

Enhancing the reactivity of 1,2,3-triazoles in "click" macrocycles by face-to-face dibenzylammonium ion binding.

A face-to-face binding motif between dibenzylammonium ions and macrocycles containing 1,2,3-triazoles was established, which operates cooperatively to enhance the reactivity of 1,2,3-triazoles in an Arbuzov-type dealkylation reaction.