The depletion of fresh water resources leads to the utilisation of various alternative sources of water, such as seawater. In this regard, the foliar application of proline is one of the alternative shotgun approaches to increase plant stress tolerance. A pot experiment was conducted in the wire house of the National Research Centre, Dokki, Cairo, Egypt, during the winter season of 2010–2011. The experiment consisted of three concentrations of proline (0, 25 and 50mM) and two concentrations of diluted seawater (3.13 and 6.25dSm−1), whereas control plants were irrigated with tap water (0.23dSm−1). Diluted seawater caused significant reductions in growth parameters, photosynthetic pigments, some mineral contents (P, K, Ca+2), the K+:Na+ ratio and the level of total carbohydrates. In contrast, N, Na+, and Cl− contents, osmoprotectants (soluble carbohydrates, total phenolic concentrations, free amino acids, proline), and activities of antioxidant enzymes (peroxidase and polyphenol oxidase) significantly increased with an increasing salinity level compared with control plants. The foliar application of 25mM proline caused significant increases in growth parameters, photosynthetic pigments, N, P, K+, and Ca+2 %, the K+:Na+ ratio, total carbohydrates, and soluble carbohydrates, accompanied by significant decreases in Na+, Cl−, phenolic contents, free amino acids, proline, and the activities of antioxidant enzymes compared with the control. In addition, 25mM proline minimised the deleterious effect of salinity on the anatomical structure of the faba bean stem and leaf. The proline treatment at 50mM was as essentially toxic to faba bean plants as to that of salinity stress. This toxicity was apparent by the reduction of growth parameters, photosynthetic pigments, N, P, K+, and Ca+2, K+:Na+ ratio and significant increases in Na+ and Cl− concentrations. Therefore, the exogenous application of proline at a concentration of 25mM partially alleviated the toxicity of diluted seawater on faba bean plants, whereas the 50mM proline treatment was toxic

Oxidative stress and related diseases resulting from the overproduction of free radicals can be counteracted by designing and developing novel antioxidative agents that can protect the human body against the damage caused by free radicals. The present study evaluated the antioxidant activities of 15 derivatives of 2-thioxobenzo[g]quinazoline using three different assays: 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging, reducing power capability, and ferric reduction antioxidant power. Some benzoquinazolines had good activity and had the capacity to deplete DPPH and free radicals compared to a positive control butylated hydroxyl toluene (BHT). A docking study identified the possible interactions between binding models and the antioxidant activities of the target compounds. The active compounds can be used as templates for further development of more potent antioxidative agents.

Aim: The present study was carried out to assess a new series of triazoloquinazolines 1–40 for their antioxidant activities using 1,1-diphenyl-2-picryl hydrazyl radical scavenging, ferric reduction antioxidant power and reducing power capability assays. Results: All triazoloquinazolines 1–40 exhibited antioxidant activity ranged from weak to moderate and high. The obtained findings revealed that the triazoloquinazolines 30, 36 and 38–40 have superiority among all compounds, demonstrating the highest capacity to deplete 1,1-diphenyl-2-picryl hydrazyl and free radicals, in relation to butylated hydroxyl toluene, as a synthetic antioxidant agent. Conclusion: Chemical modifications together with density functional theory study on the targets supplied us with some valuable clarifications about the required properties needed for the target compounds to be more active against free radicals.