Multicomponent Strategy to Pyrazolo[3,4-b]pyrrolo[3,4-d]pyridine Derivatives under Microwave Irradiation.

A novel three-component reaction has been established that allows a flexible and practical approach to pyrazolo[3,4-b]pyrrolo[3,4-d]pyridine derivatives from phenylglyoxal, ß-ketoamide, and 5-aminopyrazole with acetic acid as the solvent. Various dihydropyrazolo[3,4-b]pyrrolo[3,4-d]pyridin-6(3H)-one were isolated in moderate to good yields with broad functional group tolerance.

Investigation of Film with ß-Galactosidase Designed for Stabilization and Handling in Dry Configuration.

Gelatin-based films with an immobilized enzyme designed for extending the stability of the protein in dry, non-powder configuration with precise dosing attributes were subjected to stress conditions of temperature and relative humidity. ß-galactosidase was used as model functional protein. The film configuration preserved the activity of the enzyme under the different storage conditions investigated, which include room temperature under low (ambient) and high (75%) relative humidity, and 36 °C under low (oven) and high relative humidity conditions for a period of 46 days. The influence of the enzyme and plasticizer (glycerol) on the physical and mechanical properties of the films was investigated using DMA (dynamic mechanical analysis). Films containing 5% ß-galactosisdase and glycerol concentrations of 14% or greater exhibited greater tensile strength, Young's modulus, and elongation at break than films with equal concentrations of plasticizer but devoid of any enzyme. The surface texture of the films was analyzed using scanning electron microscopy (SEM). ß-galactosidase and glycerol have opposite effects on the surface morphology of the films. Increasing concentrations of the enzyme result in rougher film surface, whereas increasing the concentration of glycerol leads to films with denser and smoother surface. The results obtained suggest that the dry film configuration approach can help in facilitating the stabilization, handling, storage, and transportation of functional proteins in a cost effective manner.

A facile cation exchange-based aqueous synthesis of highly stable and biocompatible Ag2S quantum dots emitting in the second near-infrared biological window.

Second near-infrared (NIR-II) emitting Ag2S quantum dots (QDs) with high stability and biocompatibility were synthesized and developed toward an ideal nanoprobe. This study reports a facile synthesis of NIR-II Ag2S QDs on the basis of cation exchange between visible-emitting CdS QDs and Ag(+) ions in aqueous solution. Experimental data testified that the cation exchange was quick and complete and that the resultant products were single monoclinic Ag2S without CdS QDs. The prepared Ag2S QDs were systematically characterized, showed typical NIR-II emission and high PL stability, and had small diameters (~3.5 nm) and a quantum yield up to 2.3%. The results of cytotoxicity assay suggested that the Ag2S QDs produced negligible effects in altering the cell proliferation or in generating reactive oxygen species, indicating an ultralow cytotoxicity and an excellent biocompatibility. These properties have opened up the possibility of using Ag2S QDs for effective bioimaging applications.

6-Meth-oxy-meth-oxy-7-trifluoro-methyl-1,3-benzodioxole-5-carbaldehyde.

The title compound, C(11)H(9)F(3)O(5), crystallizes with three mol-ecules in the asymmetric unit. One -CF(3) group is disordered by rotation, with the F atoms split over two sets of sites with occupancies which converged to 0.888 (6) and 0.112 (6). Weak π-π inter-actions are observed between adjacent benzene rings [the shortest centroid-centroid distance is 3.8858 (4) Å], resulting in the formation of a supra-molecular chain along [100].