Quinazoline-2,4( $$1H,3H$$ )-diones inhibit the growth of multiple human tumor cell lines

Design and synthesis of a new series of hybrids of functionalised N1-[(1H-1,2,3-triazol-4-yl)methyl]quinazoline-2,4-dione with antiviral activity against Respiratory Syncytial Virus

In this study, a series of 48 hybrids of the functionalised 1-[(1H-1,2,3-triazole-4-yl)methyl]quinazoline-2,4-dione 17-22 were synthesised and evaluated for potential antiviral activity. The new hybrids were designed to contain a diethoxyphosphoryl group connected to the triazole moiety via ethylene or propylene linker, and in which the benzyl or benzoyl function is substituted at N3 in the quinazoline-2,4-dione moiety. The Cu(I)-catalyzed Hüisgen dipolar cycloaddition of azidophosphonates 23 and 24 with the respective N¹-propargylquinazoline-2,4-diones 26aa-26ag, 26ba-26bg, 27aa-27ad and 27ba-27bd was applied for the syntheses of the designed compounds. All final hybrids 17-22 and N3-functionalised N¹-propargylquinazoline-2,4-diones 26 and 27 were subsequently evaluated for their antiviral activity toward a broad range of DNA and RNA viruses. Importantly, hybrids 19be-19bg and 20be-20bg showed profound antiviral activities against Respiratory Syncytial Virus (RSV) with EC₅₀ values in the lower micromolar range, with activity against viral strains of both subtypes (RSV A and B). In addition, several compounds also exerted some weak antiviral activity against varicella zoster virus. Finally, 19 ag was the only compound that showed antiviral potency against human cytomegalovirus, although with rather weak inhibitory activity. Notably, none of the tested compounds was cytotoxic toward uninfected cell lines used for the antiviral assays at a concentration up to 100 μM, returning interesting therapeutic indices for respiratory syncytial virus.

Discovery of Quinazoline-2,4(1H,3H)-Dione Derivatives as Potential Antibacterial Agent: Design, Synthesis, and Their Antibacterial Activity

In this paper, we report on the design and synthesis of a novel series of quinazoline-2,4(1H,3H)-dione derivatives as fluoroquinolone-like inhibitors of bacterial gyrase and DNA topoisomerase IV to identify and develop antimicrobial agents to prevent bacterial resistance problems. Their structures were confirmed using spectroscopic analyses (IR, NMR, and EI-MS). The novel quinazoline-2,4(1H,3H)-dione derivatives were evaluated for their antimicrobial activities against Gram-positive and Gram-negative bacterial strains using the Agar well diffusion method to study the antimicrobial activities and compared them with the standard drugs. Most compounds displayed moderate activity. Among the tested compounds, the most promising compounds 13 and 15 provided broad bioactive spectrum against Gram-positive and Gram-negative strains compared to the standard drugs.

I2/TBHP mediated domino synthesis of 2-(2,4-dioxo-1,4-dihydroquinazolin-3(2H)-yl)-N-aryl/alkyl benzamides and evaluation of their anticancer and docking studies

A novel I2/TBHP mediated domino synthesis of 2-(2,4-dioxo-1,4-dihydroquinazolin-3(2H)-yl)-N-phenyl benzamides by reaction of isatins with o-amino N-aryl/alkyl benzamides was described. This was the first application of o-amino N-aryl/alkyl benzamides participating in oxidative rearrangement with isatins for synthesis of desired products. The synthesized compounds contained amide and quinazoline units and their combination resulted in molecular hybridization of two important pharmacophores. In this study, the synthesized compounds 3a-r were screened for cytotoxicity against four cancer cell lines A549, DU145, B16-F10, and HepG2 and also non-cancerous cell line CHO-K1. The compounds 3c, 3l and 3o gave promising results. The in silico molecular docking studies (PDB ID 1N37) also validated the anticancer activity of these compounds showing good binding affinity with target DNA and by acting as DNA intercalators.

Benzothiazoles exhibit broad-spectrum antitumor activity: their potency, structure-activity and structure-metabolism relationships

An antitumor activity oriented benzothiazole sublibrary was constructed from a hit compound 3 via a five stepwise procedure. All target compounds were screened for their antitumor activity against 60 human cancer cell lines. Compounds 9p, 12d and 12i, showing higher potency than hit 3, were identified. Particularly, the compound 9p gave its average 50% growth inhibition (GI₅₀) at 0.38 μM. Furthermore, incubation in human liver microsome primarily proved their metabolic stability in vitro. General structure-activity and structure-metabolism relationships were both summarized, which provides information on further strategically optimization.