Sevdije Govori

Transition metal complexes with heteroaromatic ligands offer a promising strategy for developing novel anticancer agents. In this study, the ligand 12-hydroxy-7-iminocromeno[4,3- d]pyrido[1,2-a]pyrimidin-6(7H)-one was used to synthesize new cobalt(II), nickel(II), and titanium( III/IV) complexes via conventional and microwave-assisted methods, with the latter providing higher yields and shorter reaction times. The complexes were characterized by FT-IR, ¹H- and ¹³CNMR, mass spectrometry, and elemental analysis, confirming coordination through the azomethine nitrogen and phenolic oxygen atoms. Their in vitro antiproliferative activity was evaluated against the H460, MCF-7, and HCT116 human cancer cell lines, with doxorubicin used as a positive control. Cytotoxicity was expressed as GI₅₀ values. All complexes exhibited moderate to pronounced antiproliferative effects. The nickel(II) and cobalt(II) complexes showed moderate activity, whereas the titanium( III/IV) complexes were the most potent, displaying significantly higher cytotoxicity than the free ligand, with GI₅₀ values in the low micromolar range. These findings highlight the influence of the metal center on biological activity and identify the titanium complexes as promising candidates for further anticancer studies.

The purpose of this paper is the synthesis of new metal complexes and their biological application. Four new transition metal complexes (2–5) were synthesized using conventional as well as microwave methods from 7-iminochromeno[4,3-d]pyrido[1,2-a]pyrimidin-6(7H)-one (1) and corresponding metal salts. Ligand 1 and metal complexes 2–5 were characterized by IR, 1H-NMR, 13 C-NMR, Mass spectroscopy and elemental analysis. The free ligand and the metal complexes have been tested for in vitro antiproliferative activity. The evaluation of the antiproliferative effects of compounds (1–5) on three tumor cell lines (H460, MCF-7, and HCT116) shows that all tested compounds have demonstrated moderate to pronounced antiproliferative and/or cytotoxic effect. The most active compounds were ligand 1 and metal complexes 3 and 5.

The biological activity of heterocyclic compounds depends on their structure, the type of hetero atoms in the ring and on the type of substituents present. In this paper, some heterocyclic compounds with coumarin moieties S1–S5 and novobiocin known as coumarin antibiotic were subjected to the molecular docking studies as important tools for drug discovery. Glucosamine-6-phosphate synthase is selected as a suitable target in this study. In silico studies reveal that all synthesized compounds S1–S5 are good inhibitors of GlcN-6 and the docking results are in agreement with in vitro antibacterial evaluation of compounds S1–S5

This review describes the preparation of pentacyclic fused heterocycles with the coumarin moiety. These derivatives are reported as biologically active compounds. GRAPHICAL ABSTRACT

4-(5-(Methylthio)-1,3,4-thiadiazol-2-ylamino)-2-oxo-2H-chromene-3-carbaldehyde (3) and 4-(5-(ethylthio)-1,3,4-thiadiazol-2-ylamino)-2-oxo-2H-chromene-3-carbaldehyde (4) were prepared. The structures of the newly synthesized compounds were characterized by infrared (IR), nuclear magnetic resonance (NMR) spectral data and elemental analysis. The synthesized compounds were screened in vitro for their antibacterial activities. The synthesized compounds demonstrated moderate antimicrobial activity.

3,4-Annelated coumarin-pyrimido-pyrimidine systems (7-imino-8-mercapto-7H-5-oxa-7a,9,12-triaza-benzo[a]anthracen-6-one 2 and 8-hydroxy-7-imino-10-methyl-7H-5-oxa-7a,9,12-triaza-benzo[a]anthracen-6-one 3 ) were synthesized by the action of 4-amino-2-mercapto-pyrimidine, 2-amino-4-hydroxy-6-methylpyrimidine, respectively, on 4-chlorocoumarin-3-carbonitrile 1 . The synthesized compounds were examined for in vitro antibacterial activity against 4 bacterial cultures: Staphylococcus aureus, Streptococcus pneumonia, Escherichia coli, and Aeromonas Salmonicida. The antibacterial activity of synthesized compounds 2 and 3 was compared to antibacterial activity of novobiocin as a standard drug.

Nucleophilic substitution of 4-chloro-3-nitro-2-oxo-2H-chromen-2-one 3 by 6-chloro-7H-purin-2-ylamine ( a ), yielded the corresponding 4-(6-chloro-7H-purin-8-ylamino)-3-nitro-chromen-2-one 4 . The chemical structure of synthesized compound was characterized using IR and NMR spectra, and elemental analyses. The purified synthesized compound 4 was tested at concentrations 1, 3, 5 mg/ml for its antibacterial activity against three bacterial cultures: Staphylococcus aureus, Escherichia coli, and Bacillus cereus. The antibacterial activity of synthesized compound was compared to antibacterial activity of standard antibiotics cephalexine and streptomycin.

Antimicrobial activity and chemical composition of the essential oil of Juniperus communis (L.), originated from east part of Kosova, was investigated. The essential oil from berries of J. communis (L.), obtained by hydro-distillation was analyzed by GC and GC-MS. Antimicrobial properties of the essential oil of J. communis (L.) are investigated and results are submitted for their activities against Staphylococcus aureus, Escherichia coli, Hafnia alvei and Pseudomonas aeruginosa. Applying the agar disc diffusion technique, we measured diameters of the inhibition zone around discs, which are previously wetted with DMF solution of the essential oil with three different concentrations, 1, 3 and 5 mg mL-1. Analysis of the oil resulted in the identification of 41 peaks, representing 96% of the oil. Berry essential oil composed mainly of monoterpenoids which amounted to 83%, of which 69.4% was monoterpene hydrocarbons. The main monoterpene hydrocarbons were α-pinene (36.2%) and β-myrcene (21.1%). The sesquiterpene accounted for about 13.4% of the total oil composition. Germacrene D (2.2%), α-cadinol (1.6%), α-humulene (1.5%), spathulenol (1.4%), epi-α-bisabolol (1.3%) and germacrene B (1.1%) were the main constituents of the sesquiterpenes. The inhibition zone depends from concentrations and also from sort of bacteria. The inhibition zones differ from 0-39 mm. The present work presents the chemical composition of the hydrodistilled oil of J. communis (L.) from East part of Kosova and the results are compared to those reported in the literature. This study demonstrates the occurrence of α-pinene chemotype of J. communis (L.) from east part of Kosova. The essential oil of J. communis (L.) growing wild in Kosova, showed moderate to high activities against Staphylococcus aureus, Escherichia coli, Hafnia alvei. Pseudomonas aeruginosa is resistant to the essential oil of J. communis (L.) growing wild in east part of Kosova.