Valorizing pomegranate wastes by producing functional silver nanoparticles with antioxidant, anticancer, antiviral, and antimicrobial activities and its potential in food preservation.

The food sector generates massive amounts of waste, which are rich in active compounds, especially polyphenols; therefore, valorizing these wastes is a global trend. In this study, we produce silver nanoparticles from pomegranate wastes, characterized by enhanced antioxidant, anticancer, antiviral, and antimicrobial properties and investigated their potential to maintain the fruit quality for sixty days in market. The pomegranate waste-mediated silver nanoparticles (PPAgNPs) were spherical shape (measured by TEM), 20 nm (Zeta sizer), negatively charged -25.98 mV (Zeta potential), and surrounded by active groups (FTIR). The PPAgNPs scavenged 94 % of DPPH radicals and inhibited the growth of pathogens, i.e., Staphylococcus aureus, Listeria monocytogenes, Campylobacter jejuni, Salmonella typhi and Candida with inhibition zones diameters (16-45 mm). They impeded the development of breast and colon cancer cell lines by 80 and 78 %, increased the activity of apoptosis marker caspase 3, and inhibited 82 % of COVID-19. The PPAgNPs were added to the rat diet at 80, 160, and 320 µg/kg levels. PPAgNPs administered at a concentration of 160 µg/kg in the rat diet resulted in the best growth performance, normal liver and kidney parameters (p = 0.029-0.038), lowered lipid profile, malondialdhyde (MDA), and raised glutathion reduced (GSH), total protein (TP). Also, the reduced gene expression of Interleukin 6 (IL-6) and Tumor necrosis factor alpha (TNF-α) in albino rats' serum indicates the anti-inflammatory effect of PPAgNPs. PPAgNPs developed a functional coating to preserve mandarin fruit for 60 days by dipping technique. The active coat containing PPAgNPs can effectively preserve the fruit for 60 days.

Validated spectrofluorimetric method for the determination of netilmicin based on its interaction with o-phthalaldehyde/mercaptoethanol: Evaluation of the method's greenness.

In this study, netilmicin (NTM) was selectively assessed in its dosage forms after a facile derivatization reaction. The proposed approach was based on the interaction between NTM and o-phthalaldehyde/2-mercaptoethanol (Roth's reagent). The reaction product was fluorometrically measured at λemission of 434 nm after λexcitation of 338 nm. All reaction conditions for achieving the optimum fluorescence switch-on activity were visualized and monitored. Moreover, the method was validated under ICH guidelines, and was linear over the range 30-210 ng/ml after plotting netilmicin concentrations against the corresponding fluorescence intensity values. In addition, the selectivity of the developed method was investigated against either the co-formulated drug (dexamethasone) or a common ophthalmic drop excipient (benzalkonium chloride) without interference from either of them. Furthermore, the developed method was applied to assay netilmicin in various samples of pharmaceutical eye drops with good recovery. Finally, multicriteria greenness and whiteness metrics were used to evaluate the sustainability, greenness, and whiteness of the approach. The applied tools were the AGREE algorithm, the RGB 12 algorithm, and HEXAGON.

Synthesis of green emitted carbon dots from Vachellia nilotica and utilizing its extract as a red emitted fluorescence reagent: Applying for visual and spectroscopic detection of iron (III).

Principles of Green Analytical Chemistry recommended preferring using reagents from renewable sources and eliminating toxic reagents. Vachellia nilotica is a widespread plant throughout different parts of the world. In this study, using microwave energy, fluorescent carbon dots were synthesized for the first time from Vachellia nilotica pods. The morphology of the prepared carbon dots was characterized by SEM and TEM techniques, and the spectroscopic character exhibit green emission at 480 nm at λex = 386.5 nm. This fluorescence can be effectively quenched by adding Fe (III) ions (Method I). Furthermore, Vachellia nilotica pods were extracted by different solvents, including methanol, deionized water, absolute ethanol, acetone, acetonitrile, and DMF. The acetonitrile extract of Vachellia nilotica exhibited a strong red fluorescence emission at 673.9 at λex = 410 nm. Among various types of salt metals, only Fe (III) can effectively quench the fluorescence intensity of the acetonitrile extract (method II). Moreover, the bright yellow color of the aqueous extract can be changed into violet color. The absorbance of the resulted color can be spectrophotometrically measured at λ max = 530 nm (method III). The best analytical factors were optimized for the developed methods. The developed methods were applied to determine Fe (III) in different water samples.