Au@SiO2 core-shell nanoparticles for laser desorption/ionization time of flight mass spectrometry.

In matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS), the analysis capability, especially for small molecules, is often compromised by the addition of organic matrices due to the existence of background signals. Herein we report a new detection method on the utility of core-shell nanoparticles (CSNPs) as energy transfer structure in LDI-TOF-MS. The LDI-TOF-MS based on gold-silica core-shell nanoparticles with ultrathin silica shell of 2-4 nm (Au@utSiO(2) CSNPs) was effectively applied to the analysis of many compounds, especially for small functional molecules and polymers, which was more promising than MALDI-TOF-MS.

Microwave assisted synthesis and antimicrobial evaluation of new fused pyran derivatives bearing 2-morpholinoquinoline nucleus.

A new series of fused pyran derivatives 5a-x bearing 2-morpholinoquinoline nucleus has been synthesized under microwave irradiation by a reaction of 2-morpholinoquinoline-3-carbaldehyde 2a-c, malononitrile 3 and compounds 4a-h in presence of NaOH as basic catalyst. All the compounds were screened against three Gram positive bacteria (Streptococcus pneumoniae, Clostridium tetani, Bacillus subtilis), three Gram negative bacteria (Salmonella typhi, Vibrio cholerae, Escherichia coli) and two fungi (Aspergillus fumigatus, Candida albicans) using broth microdilution MIC (Minimum Inhibitory Concentration) method. Of the compounds studied, compounds 5b, 5f, 5k, 5m, 5q, 5s and 5v have found to be most efficient members of the series.

Synthesis and identification of β-aryloxyquinolines and their pyrano[3,2-c]chromene derivatives as a new class of antimicrobial and antituberculosis agents.

A new class of β-aryloxyquinolines 3a-i and their pyrano[3,2-c]chromene derivatives 6a-r incorporating a validated molecular target has been synthesized via a nucleophilic displacement and a one-pot multicomponent reaction respectively. In vitro antimicrobial activity of the synthesized compounds were investigated against a representative panel of pathogenic strains specifically Bacillus subtilis, Clostridium tetani, Streptococcus pneumoniae, Escherichia coli, Salmonella typhi, Vibrio cholera, Aspergillus fumigatus and Candida albicans. Compounds 3c, 3e, 3g, 6f, 6l and 6q exhibited excellent antibacterial activity while compound 6p exhibited more potent antifungal activity than that of first line standard drugs.