A New Coumarin-Based Fluorescent pH Probe

A new iminocoumarin-derived colorimetric and fluorescent pH probe was developed for rapid and sensitive detection of pH changes in biological and environmental media. With the decrease of pH value( from 6. 24 to 3. 00),an obvious color change of the probe in ethanol-water solution from green to yellow was observed under nature light. The intensity of the maximum fluorescence emission peak of the probe decreased gradually with the acidity increase of the solution. While the fluorescence intensity of the emission peak of the probe did not exhibit distinct change when pH was less than 11. 00 and the fluorescence was almost quenched at pH 13. 50. Sensitivity of the fluorescent pH probe was not interfered by the presence of common metal cations and anions.

3-(Tetrazol-5-yl)-2-imino-coumarins Derivatives: Synthesis, Characterization, and Evaluation on Tumor Cell Lines

The first report of new 3-(tetrazol-5-yl)-2-iminocoumarin derivatives is described. The title compounds were prepared in two steps and were obtained in good yields (55-93%). They have been fully characterized by 1H, 13C NMR, FTIR, UV-Visible and HRMS. They were tested for their antiproliferative activities against six representative human tumor cell lines (Huh 7-D12, Caco2, MDA-MB231, HCT 116, PC3 and NCI-H727) and HaCat keratinocytes. Among them, compound 5e was active on HCT 116 (IC50 15 μM).

Synthesis of New 2-Phenylamino-4<i>H</i>-chromene-3-carbonitrile Derivatives and Their Effects on Tumor Cell Lines and against Protein Kinases

The synthesis of 2-phenylimino-4H-chromene-3-carbonitriles 6(a-d) in good overall yields using an efficient and practical methodology in 3 steps has been implemented in this present work. The first step was a heterocyclization between 2-hydroxybenzaldehyde 1 and propanedinitrile 2 which produced 2-iminocoumarin 3 which was submitted to nitrogen/nitrogen displacement in the presence of aromatic primary amine 4. In the third step, reduction of 5 led to the desired 2-phenylimino-4H-chromene-3-carbonitriles 6. Compounds 5(a-d) and 6(a-d) were evaluated for their potential in vitro cytotoxicity against six selected tumor cell lines (Huh7-D12, Caco2, MDA-MB231, HCT 116, PC3 and NCI-H727) and tested for their protein kinase inhibition on eight selected protein kinases. Among them, compounds 5c and 6b exhibited inhibition on HsCK1e (5c: 44% and 6b: 42% at 1 μM) and 5c for cytotoxicity on PC3 cell lines (63% at 25 μM).