Chemosensing Properties of Coumarin Derivatives: Promising Agents with Diverse Pharmacological Properties, Docking and DFT Investigation

In this work, a three-component reaction of 3-acetyl-4-hydroxycoumarine, malononitrile, or cyanoacetate in the presence of ammonium acetate was used to form coumarin derivatives. The chemical structures of new compounds were identified by ¹H, ¹³C NMR and an elemental analysis. These compounds were examined in vitro for their antimicrobial activity against a panel of bacterial strains. In addition, these compounds were investigated for antioxidant activities by superoxideradical, DPPH (2,2-Diphenyl-1-picrylhydrazyl), and hydroxyl radical scavenging assays, in which most of them displayed significant antioxidant activities. Furthermore, these compounds were evaluated for anti-inflammatory activity by indirect hemolytic and lipoxygenase inhibition assays and revealed good activity. In addition, screening of the selected compounds 2–4 against colon carcinoma cell lines (HCT-116) and hepatocellular carcinoma cell lines (HepG-2) showed that that 2-amino-4-hydroxy-6-(4-hydroxy-2-oxo-2H-chromen-3-yl)nicotinonitrile 4 exhibited good cytotoxic activity against standard Vinblastine, while the other compounds exhibited moderate cytotoxic activity. Docking simulation showed that2-amino-4-hydroxy-6-(4-hydroxy-2-oxo-2H-chromen-3-yl)nicotinonitrile 4 is an effective inhibitor of the tumor protein HCT-116. A large fluorescence enhancement in a highly acidic medium was observed, and large fluorescence quenching by the addition of traces of Cu²⁺ and Ni²⁺ was also remarked.

Umbelliferone Decorated Water-soluble Zinc(II) Phthalocyanines - In Vitro Phototoxic Antimicrobial Anti-cancer Agents

In this contribution we report on the synthesis, characterization and application of water-soluble zinc(II) phthalocyanines, which are decorated with four or eight umbelliferone moieties for photodynamic therapy (PDT). These compounds are linked peripherally to zinc(II) phthalocyanine by a triethylene glycol linker attached to pyridines, leading to cationic pyridinium units, able to increase the water solubility of the system. Beside their photophysical properties they were analyzed concerning their cellular distribution in human hepatocyte carcinoma (HepG2) cells as well as their phototoxicity towards HepG2 cells, Gram-positive (S. aureus strain 3150/12 and B. subtilis strain DB104) and Gram-negative bacteria (E. coli strain UTI89 and E. coli strain Nissle 1917). At low light doses and concentrations, they exhibit superb antimicrobial activity against Gram-positive bacteria as well as anti-tumor activity against HepG2. They are even capable to inactivate Gram-negative bacteria, whereas the dark toxicity remains low. These unique water-soluble compounds can be regarded as all-in-one type photosensitizers with broad applications ranges in the future.

Novel Nonmetalated Hydrophobic and Metalated Phthalocyanines Bearing Pyridine-2-Thiol and 2,4,6-Trimethylphenylamine Substituents: Synthesis, Spectroscopic, Aggregation and Thermal Properties

Novel metal–free and metallo-phthalocyanines, with different substituents at peripheral positions, have been synthesised by cyclotetramerisation of 4-(2,4,6-trimethylphenylamino)phthalonitrile and 4-(pyridine-2-ylsulfanyl)phthalonitrile in the presence of the corresponding divalent metal salts [Zn(II), Cu(II), Co(II) and Ni(II)]. Quaternisation of the metallophthalocyanine functionality produced quaternised cationic Zn, Cu, Ni and Co phthalocyanines, which are soluble in DMF, H2O and DMSO. The aggregation behaviour of these compounds was investigated in different concentrations of DMSO. Their thermal stability and electronic stability are reported.