ZIGIR, a Granule-Specific Zn Indicator, Reveals Human Islet α Cell Heterogeneity.

Numerous mammalian cells contain abundant Zn in their secretory granules, yet available Zn sensors lack the desired specificity and sensitivity for imaging granular Zn. We developed a fluorescent zinc granule indicator, ZIGIR, that possesses numerous desired properties for live cell imaging, including >100-fold fluorescence enhancement, membrane permeability, and selective enrichment to acidic granules. The combined advantages endow ZIGIR with superior sensitivity and specificity for imaging granular Zn.

Protein-induced fluorescence enhancement of two-photon excitable water-soluble diketopyrrolopyrroles.

Fluorescent contrast agents are important tools in cell biology and medical imaging due to their high sensitivity and relative availability. Diketopyrrolopyrrole (DPP) derivatives have been recently studied for applications in bioimaging, but certain drawbacks due to their inherent structure have stifled progress towards their widespread implementation. Aggregation caused quenching (ACQ) associated with π-π stacking in relatively rigid extended conjugation systems as well as hydrophobicity of previously reported DPPs make most unsuitable for biological imaging applications.

Computer aided chemical design: using quantum chemical calculations to predict properties of a series of halochromic guaiazulene derivatives.

With the scientific community becoming increasingly aware of the need for greener products and methodologies, the optimization of synthetic design is of greater importance. Building on experimental data collected from a synthesized guaiazulene derivative, a series of analogous structures were investigated with time-dependent density functional theory (TD-DFT) methods in an effort to identify a compound with desirable photophysical properties. This analysis may eliminate the need to synthesize numerous materials that, when investigated, do not possess viable characteristics.

Pegylated and nanoparticle-conjugated sulfonium salt photo triggers necrotic cell death.

Photodynamic therapy (PDT) processes involving the production of singlet oxygen face the issue of oxygen concentration dependency. Despite high oxygen delivery, a variety of properties related to metabolism and vascular morphology in cancer cells result in hypoxic environments, resulting in limited effectiveness of such therapies. An alternative oxygen-independent agent whose cell cytotoxicity can be remotely controlled by light may allow access to treatment of hypoxic tumors.

Total synthesis of teixobactin.

To cope with the global bacterial multidrug resistance, scientific communities have devoted significant efforts to develop novel antibiotics, particularly those with new modes of actions. Teixobactin, recently isolated from uncultured bacteria, is considered as a promising first-in-class drug candidate for clinical development. Herein, we report its total synthesis by a highly convergent Ser ligation approach and this strategy allows us to prepare several analogues of the natural product.

α-Substitution effects on the ease of S→N-acyl transfer in aminothioesters.

In S-acylcysteines and homocysteines, the efficacy and rate of S→N-acyl transfer (5 and 6 cyclic TSs) vary with the size of S-acyl group. Conformational and quantum chemical calculations indicate that the spatial distance, b(N-C), between the terminal amine and the thioester carbon is shortened by α-C(O)X (X = OH, OMe, NH2 ) substituents.

Amino acyl conjugates of nitrogen heterocycles as potential pharmacophores.

2-Methyl- and 4-methylpyridine and 2-methylquinoline are converted by benzotriazole-activated (Cbz)-protected amino acids into chiral potential novel pharmacophore aminoacyl conjugates (33-53%).