Synthesis and in vitro investigation of halogenated 1,3-bis(4-nitrophenyl)triazenide salts as antitubercular compounds.

The diverse pharmacological properties of the diaryltriazenes have sparked the interest to investigate their potential to be repurposed as antitubercular drug candidates. In an attempt to improve the antitubercular activity of a previously constructed diaryltriazene library, eight new halogenated nitroaromatic triazenides were synthesized and underwent biological evaluation. The potency of the series was confirmed against the Mycobacterium tuberculosis lab strain H37Ra, and for the most potent derivative, we observed a minimal inhibitory concentration of 0.85 µm. The potency of the triazenide derivatives against M. tuberculosis H37Ra was found to be highly dependent on the nature of the halogenated phenyl substituent and less dependent on cationic species used for the preparation of the salts. Although the inhibitory concentration against J774A.1 macrophages was observed at 3.08 µm, the cellular toxicity was not mediated by the generation of nitroxide intermediate as confirmed by electron paramagnetic resonance spectroscopy, whereas no in vitro mutagenicity could be observed for the new halogenated nitroaromatic triazenides when a trifluoromethyl substituent was present on both the aryl moieties.

Diaryltriazenes as antibacterial agents against methicillin resistant Staphylococcus aureus (MRSA) and Mycobacterium smegmatis.

Diaryltriazene derivatives were synthesized and evaluated for their antimicrobial properties. Initial experiments showed some of these compounds to have activity against both methicillin-resistant strains of Staphylococus aureus (MRSA) and Mycobacterium smegmatis, with MICs of 0.02 and 0.03 µg/mL respectively. Those compounds with potent anti-staphylococcal and anti-mycobacterial activity were not found to act as growth inhibitors of mammalian cell lines or yeast. Furthermore, we demonstrated that one of the most active anti-MRSA diaryltriazene derivatives was subject to very low frequencies of resistance at <10-9. Whole genome sequencing of resistant isolates identified mutations in the enzyme that lysylates phospholipids. This could result in the modification of phospholipid metabolism and consequently the characteristics of the staphylococcal cell membrane, ultimately modifying the sensitivity of these pathogens to triazene challenge. Our work has therefore extended the potential range of triazenes, which could yield novel antimicrobials with low levels of resistance.

Synthesis and X-ray Structural Analysis of the Ruthenium(III) Complex Na[trans-RuCl4(DMSO) (PyrDiaz)], the Diazene Derivative of Antitumor NAMI-Pyr.

Novel tetrachloridoruthenium(III) complex Na[trans-RuCl4(DMSO)(PyrDiaz)] (3) with pyridine-tethered diazenedicarboxamide PyrDiaz ligand (PyrDiaz = N1-(4-isopropylphenyl)-N2-(pyridin-2-ylmethyl)diazene-1,2-dicarboxamide) was synthesized by direct coupling of PyrDiaz with sodium trans-bis(dimethyl sulfoxide)tetrachloridoruthenate(III) (Na-[trans-Ru(DMSO)2Cl4]). Compound 3 is the analogue of the antimetastatic Ru(III) complex NAMI-A and NAMI-Pyr. Single crystal X.

The 1,3-diaryltriazenido(p-cymene)ruthenium(II) complexes with a high in vitro anticancer activity.

1,3-Diaryltriazenes (1) were let to react with [RuCl2(p-cymene)]2 in the presence of trimethylamine to give neutral 1,3-diaryltriazenido(p-cymene)ruthenium(II) complexes, [RuCl(p-cymene)(ArNNNAr)] (2). The molecular composition of the products 2 was confirmed by NMR spectroscopy and mass spectrometry. The structures of the selected complexes were confirmed by a single crystal X-ray analysis. All triazenido-ruthenium complexes were highly cytotoxic against human cervical carcinoma HeLa cells with IC50 below 6µM, as determined by a spectrophotometric MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide) method. The most active was [RuCl(p-cymene)(ArNNNAr)] (Ar=4-Cl-3-(CF3)-C6H3) (2g) with IC50 of 0.103±0.006µM. In comparison with the data for the non-coordinated triazenes 1, the triazenido-ruthenium complexes 2 exhibited up to 560-times higher activity. Three selected complexes were highly cytotoxic also against several tumor cell lines: laryngeal carcinoma HEp-2 cells and their drug-resistant HEp-2 subline (7T), colorectal carcinoma HCT-116 cells, lung adenocarcinoma H460 cells, and mammary carcinoma MDA-MB-435 cells. The compounds 2g and [RuCl(p-cymene)(ArNNNAr)] (Ar=4-I-C6H4) (2j) were similarly cytotoxic against parental and drug-resistant cells. Time and dose dependent accumulation of the cells in the S phase of the cell cycle was induced by the compound 2g, triggering apoptosis. Our preliminary results indicate triazenido-ruthenium complexes as promising anticancer drug candidates.

Anti-mycobacterial activity of 1,3-diaryltriazenes.

The rapid generation and spread of the drug resistant tuberculosis has led to an ongoing demand for novel compounds for therapeutic use. Identification and study of compounds with the ability to inhibit Mycobacterium tuberculosis is of paramount importance. For this reason, a library of substituted 1,3-diaryltriazenes based on the acting component of the anti-trypanosomal drug, diminazene aceturate was created and evaluated for its potential as anti-tubercular agent. Several compounds were identified with sub-micro molar inhibitory concentrations against M. tuberculosis and other clinically relevant mycobacterial species such as Mycobacterium bovis, Mycobacterium avium and Mycobacterium ulcerans. Although the library of the compounds showed a considerable acute cytotoxicity, a genotoxicity could not be observed. Finally, the triazene 14 was selected with the best biological properties (IC50 = 3.26 µM, NI50 = 24.22 µM, SI = 7.44). The compound 14 showed the ability to inhibit the growth of intracellular replicating and multi-drug resistant M. tuberculosis. The results suggest the molecule to be an interesting scaffold for further study and optimization.

Synthesis and biological activity of new diazenedicarboxamides as potential anticancer agents.

To increase the effectiveness of cancer treatment, more effective anti-cancer drugs, as well as the new improved strategies of cancer treatment, are urgently needed. Our previous results have shown that various diazenes are cytotoxic to different tumor cells and can even revert the resistance to cisplatin and vincristine. We also demonstrated that unsymmetrical diazenedicarboxamides 1 and 2 exhibited promising cytotoxicity. The aim of the present study was to synthesize new diazenedicarboxamides with acceptable solubility and good cytotoxicity. Here we report the synthesis and biological evaluation of new N,N'-disubstituted diazenedicarboxamides. We found that a modification of either 1 or 2 led to the more active compounds. The most effective among them was diazenedicarboxamide 11, which can be considered as a new potential anticancer agent for the tumors of different origin, as well as for the drug resistant tumors.