This study presents the synthesis, structural characterization, and in vitro evaluation of anticancer activity of some newly benzo[f]quinoline derivatives. The synthesis is facile and efficient, involving two steps: quaternization of nitrogen heterocycle followed by a [3+2] dipolar cycloaddition reaction. The synthesized compounds were characterized by FTIR, NMR, and X-ray diffraction on monocrystal in the case of compounds 6c and 7c. An in vitro single-dose anticancer assay of eighteen benzo[f]quinoline compounds, quaternary salts, and cycloadducts, was performed. The results showed that the most active compounds were quaternary salts 3d and 3f with aromatic R substituents. Quaternary salt 3d revealed non-selective activity against all types of cancer cells, while salt 3f exhibited a highly selective activity against leukemia cells. Compound 3d also presented remarkable cytotoxic efficiency against four distinct types of cancer cells—namely, non-small cell lung cancer HOP–92, melanoma LOX IMVI, melanoma SK–MEL–5, and breast cancer MDA–MB–468. Compound 3f was selected for five-dose screening. The study also includes SAR correlations.

A green, straightforward and efficient study for obtaining hybrid quinoline-imidazole derivatives under ultrasound (US) irradiation as well as under conventional thermal heating (TH) has been presented. The reaction pathway involves only two steps: the N-alkylation of imidazole ring and a Huisgen [3 + 2] dipolar cycloaddition reaction of ylides to dimethyl acetylenedicarboxylate (DMAD). For both types of reactions, a green workup procedure under US irradiation has been presented. Under US irradiation, the N-alkylation of nitrogen atoms from the imidazole nucleus has outstanding benefits in terms of reaction time, energy consumption and yields, and can thereby be considered an environmentally friendly method. Forty new hybrid quinoline-imidazole compounds have been synthesized: 18 salts, 8 dihydro-benzopyrrolo imidazolo quinoline, 9 benzopyrrolo-imidazolo quinoline and 5 dihydro-pyrroloquinoxaline quinoline cycloadducts.

Background/Objectives Nowadays fungal infections are rising serious threats for the human health system and agriculture, mostly because of antifungal resistance, emergence of new fungal pathogens and adverse effects, pressing the scientific world for exploration of new antifungal compounds. Therefore, the aim of this work was to synthesize and to study antifungal activity against human and plant fungi of a new class of hybrid bis-(imidazole/benzimidazole)-pyridine salt derivatives. Methods: The synthesis of the hybrid derivatives was performed using both conventional thermal heating and ultrasound irradiation methods. Results:The use of ultrasound irradiation has the advantages of a dramatic decrease in reaction time and, consequently, a notable acceleration in reaction rate, a remarkable decrease in consumed energy and higher yields. The antifungal activity against five human fungal strains and for plant fungal strains was determined by the disk diffusion method and minimum inhibitory concentration. Conclusions: The tested hybrid derivatives manifest good antifungal activity against the tested strains. Some of the hybrid compounds have very good quasi-nonselective activity against the tested human and plant pathogenic fungi, in some cases close to the control drug fluconazole, respectively, to many antifungal agents commercially used for plant protection.

Nitrogen heterocycles, especially azine and azole derivatives, are highly valuable scaffolds in medicinal chemistry, being the core components of a large variety of drugs with variously biological activity such as antiplasmodial and antimalarial, antitubercular, antibacterial, antifungal, anticancer, analgesic, antidepressant, anxiolytics, antihypertensive, anticoagulants, diuretics, etc. As a result, obtaining of such entities continues to arouse a strong interest from academia and industry. As part of our ongoing research in the area of nitrogen heterocyclic derivatives, we present herein some representative results obtained by our group in the field of hybrid and chimeric azahetrocycles compounds with antimicrobial and anticancer activity. Chemistry, anticancer, antibacterial, antifungal and antituberculosis activity of compounds is presented. Some of the hybrid and chimeric structures possess a good anticancer and/or antimicrobial activity.

Quinoline-sulfonamide-complexes with variously metals, especially M2+, are a relatively new class of compounds with potential practical interest as fluorescent materials (having fotoluminiscent properties) and also as drugs (having a large variety of biological activities such as antibacterial, antifungal, antiprotozoals, etc.). The emphasis of this work was to obtain hybrid quinoline – sulfonamide - complexes with antimicrobial activity. The synthesis of the hybrid derivatives is direct and efficient, in two steps: acylation of variously amino-quinoline followed by metal complexation with different metals M2+ (Zn2+, Cu2+, Co2+, Cd2+, Ni2+, Pd2+). Following this experimental setup several series of synthetic hybrid quinoline – sulfonamide - complexes was obtained. The hybrid complexes were characterized by IR and NMR spectroscopy, elemental analysis and X-ray diffraction on single crystal. The antibacterial and antifungal activity was determined against gram positive bacteria Staphylococcus aureus ATCC25923, gram negative bacteria Escherichia coli ATCC25922 and fungus Candida albicans ATCC10231. The obtained data from the antimicrobial assay reveal that some of the obtained hybrids have a very good antimicrobial and antifungal activity.