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Introduction: In the global field of nanotechnology, the production of silver nanoparticles (AgNPs) is an environmentally beneficial technique. To prevent the diseases caused by many commonly used pesticides, it is essential to synthesize safe alternatives from low-cost sources. Material and methods: This study focuses on the eco-friendly extracellular production of AgNPs using an aqueous extract of Ulva lactuca as a reducing agent in a silver nitrate solution. The biosynthetic reaction was confirmed through various analytical techniques, including ultraviolet–visible (UV–Vis) spectroscopy, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and energy dispersive X-ray analysis (EDAX). Moreover, antioxidant activity was confirmed. It has also been evaluated against a variety of bacteria and fungi that have an impact on humans, animals, and plants. Results and discussion: The mean size of the nanoparticles (NPs) varied from 45–61 nm. The disk diffusion testing results show that, in comparison to the tested antibiotics, Staphylococcus aureus , Escherichia coli , Staphylococcus epidermidis , and Klebsiella pneumoniae were more responsive to U. lactuca -silver nanoparticles (U-AgNPs) extract. eldor 50% sc fungicide was used at the prescribed dose of 0.5 μL/mL, and the antifungal activity of aqueous and U-AgNPs extracts was examined at three concentrations of 0.62, 1.25, and 2.5 mg/mL. Through the suppression of spore germination, in vitro investigations demonstrated that U-AgNPs at varying doses greatly hindered the process of reproductive growth of Botrytis cinerea. Comparing U-AgNPs to the standard synthetic fungicide Teldor 50% sc, it is noteworthy to observe that a substantial control efficacy against tomato and strawberry gray mold was noticed, especially at concentrations of 2.5mg/mL on the entire tomato and strawberry plants and also on the detached leaves and fruits without causing any appearance damage. In summary, this study advances the field of agronanotechnology by demonstrating the potential application of a fungicide based on NPs to prevent gray mold on tomato and strawberry plants in greenhouse environments and throughout the postharvest phase. [ABSTRACT FROM AUTHOR]

The investigation of seaweeds to identify their bioactive metabolites and potential broader applications has gained significant relevance. This study aimed to analyze the proximate composition, mineral content, fatty acid profiles, water and oil-holding capacities, and antioxidant activity of various solvent extracts of Ulva lactuca. The results indicated that Ulva lactuca is characterized by its fiber content (12.68 ± 0.5%), carbohydrates (61.12 ± 1.42%), proteins (22.15 ± 1.7%), and lipids (1.3 ± 0.1%). It has a higher proportion of unsaturated fatty acids, an excellent ω-3/ω-6 ratio, and a high nutritional value. Additionally, it serves as a significant source of essential minerals, particularly potassium (K), sodium (Na), magnesium (Mg), calcium (Ca), and phosphorus (P). The methanolic extract exhibited higher levels of phenolics (45.69 ± 3.24mg gallic acid equivalents/g DM), flavonoids (15.49 ± 0.064 mg quercetin equivalents/g DM), and tannins (22.52 ± 8.23mg catechin equivalents/g DM) compared to other extracts. Using total antioxidant capacity, DPPH (2,2-Diphenyl-1-picrylhydrazyl), and reducing power assays, the results demonstrated that all three examined extracts possessed antioxidant properties. Notably, the methanolic extract showed the highest antioxidant activity, with a halfinhibitory concentration of 33.6 ± 1.31µg/ mL in the DPPH radical scavenging assay. The study also revealed that the water and oil-holding capacities of Ulva lactuca varied with temperature and were comparable to those of many commercial fiber-rich products. Sourced from the coastal waters of Kenitra, Ulva lactuca presents a viable option for applications in nutrition, pharmaceuticals, and the agri-food industry due to its biochemical composition, functional characteristics, and antioxidant properties. [ABSTRACT FROM AUTHOR]

Examines the role of lysine and tryptophan residues in the biological activity of toxin VII from scorpion Tityus serrulatus. Modification of chemicals with tryptophan-specific reagent o-nitrophenylsulfenyl chloride; Administration of Edman degradation and electrospray mass spectroscopy for acetylation; Creation of TsVII model by homology.

The venom of the scorpion Androctonus australis hector contains several protein neurotoxins of which structure and structure/activity relationships have been extensively studied. It also contains polypeptides such as Aah STR1, which are not toxic, while having highly similar sequences to fully active toxins. We have determined the solution structure of Aah STR1 by use of conventional two-dimensional NMR techniques followed by distance-geometry and energy minimization. We have demonstrated that, despite its lack of toxicity, Aah STR1 is structurally highly related to anti-mammal scorpion toxins specific for Na+ channels. The calculated structure is composed of a short α-helix (residues 26-33) connected by a tight turn to a three-stranded antiparailel β-sheet (sequences 3-6, 38-41 and 44-48). This β-sheet is righthanded twisted as usual for such secondary structures. The β-turn connecting the strands 38-41 and 4448 belongs to type II'. The overall fold of Aah STR1 is typical of β-type scorpion toxins. This is, however, the first example of such a fold in Old World scorpion toxins. Either the absence of a basic residue in position 63 or the high mobility of loops, compared to active β-type neurotoxins, may explain the lack of activity of this protein. [ABSTRACT FROM AUTHOR]