صفحة العضو

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المنشورات البحثية

الجمعة 01/سبتمبر/2023

Synthesis of Ag/Fe2O3 nanocomposite from essential oil of ginger via green method and its bactericidal activity

Fatimah A. M. Al‑Zahrani · Nourah A. AL‑Zahrani · Sameera N. Al‑Ghamdi · Long Lin · Salem S. Salem · Reda M. El‑Shishtawy

Bio-synthesized nanoparticles (NPs) having reduced chemical toxicity have been focused globally and become essential component of nanotechnology recently. In the study reported here, silver/iron oxide nanocomposite (Ag/Fe2O3) was biosynthesized from ginger oil via a green, economic, and eco-friendly strategy. The biosynthesized Ag/Fe2O3 were characterized using ultraviolet visible (UV–Vis), Fourier transform infrared (FTIR), X-ray difraction (XRD), transmission electron microscope (TEM), dynamic light scattering (DLS), and scanning electron microscope/energy-dispersive X-ray (SEM–EDX) analysis. The particulates showed a spherical-morphology and had sizes between 44 and 200 nm. Ag/Fe2O3 FTIR analysis revealed functional groups that were analogous to organic metabolites, which reduced and stabilized the nanocomposite. Antimicrobial efcacy of the biosynthesized Ag/Fe2O3 against bacterial pathogens was assessed. In addition, Ag/Fe2O3 exhibited broad spectrum activities against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa with inhibition zones 22.6±1.15, 21.1±1.44, 18±1 and 17.4±2.67 mm, respectively. The Ag/Fe2O3 showed promising antibacterial action against human bacterial pathogens, making them useful in the medical feld.

الجمعة 01/سبتمبر/2023

Advances in phenothiazine and phenoxazine-based electron donors for organic dye-sensitized solar cells

Sameera N. Al-Ghamdi, Huda A. Al-Ghamdi, Reda M. El-Shishtawy , Abdullah M. Asiri

Dye-sensitized solar cells (DSSCs) as an elegant environmental solution for renewable energy production at a lower cost than conventional silicon solar cells have been of great interest, and this review is mainly concentrated on organic dye-sensitized solar cells. It is known that the dye chromophore is a heart component in the DSSC device. Two crucial characteristics in the dye design are the electron donor moiety and its geometry. Phenothiazine (PTZ) and phenoxazine (POZ) are electron donors with a butterfly-like geometry favouring a better dye design with less dye aggregation. On the other hand, skills in the synthesis of dyes suitable for DSSCs are needed. Therefore, this review focuses on the importance of choosing the right synthetic strategies to produce efficient dye chromophores using PTZ and POZ electron donors. The impact of the auxiliary donor, auxiliary acceptor, and the presence of di or multi anchoring groups in the dye molecule on its photovoltaic performance are discussed. In addition, the review presents the possibility of spectral coverage using a mixture of PTZ-based dyes with other dyes in terms of co-sensitization, the porphyrin-PTZ and POZ panchromatic dyes, the structural dependents HOMO-LUMO energies, the stability issue, and some granted patents in DSSCs using these electron donors.

الجمعة 01/سبتمبر/2023

Flavones composition and therapeutic potential of Dodonaea viscosa against liver fibrosis

Shalaby NM, Abd-Alla HI, Hamed MA, Alghamdi SN and Jambi SM

Dodonaea viscosa (L.) Jaeq (Sapindaceae) is used in traditional medicine for the treatment of hemorrhoids, ulcer, and pains of hepatic or stomach origin. The current study was designed to investigate the phytochemical constituents of the plant and evaluate its activity against liver fibrosis induced by carbon tetrachloride (CCl4) in rats. The phytochemical analysis has afforded one flavanone; 5,7-dihydroxy flavanone (pinocembrin) (1) and eight flavones. The compounds were isolated and elucidated as; 5,7-dihydroxy-3,6,4'-trimethoxyflavone (santin) (2), 5,7,4'-trihydroxy-3-methoxy flavone (kaempferol 3-O-methyl ether) (3), 3,4',5-trihydroxy-7-methoxy flavone (kaempferol 7-O-methyl ether) (4), 3',4',5,7-tetrahydroxy-3-methoxy-flavone (quercetin 3'-O-methyl ether) (5), 3,3',4',5,7- pentahydroxyflavone (quercetin) (6), 5,7,4'-trihydroxy-3,6-dimethoxy flavone (7), 5,7-dihydroxy 3,6,3',4'- tetramethoxy flavone (8), and isorhamnetin-3-O-robinobioside (9).. In vitro screening of ethanol extract, fractions of toluene and ethyl acetate, the flavanone and major flavone compounds as antioxidants was carried out. In addition, D. viscosa ethanol extract and two fractions were examined in vivo against liver fibrosis induced by CCl4 in rats. The evaluation was done through measuring hepatic oxidative stress markers; malondialdehyde (MDA), glutathione (GSH) and superoxide dismutase (SOD). The work was extended to measure serum protein content and liver function enzymes; aspartate and alanine aminotransferases (AST and ALT), alkaline phosphatase (ALP) and gamma glutamyl transferase (GGT). Liver histopathological analysis was done for results confirmation. In conclusion, among the isolated flavones, compounds 3, 4, and 8 were isolated for the first time. The ethanol extract and compound of 6, 5 followed by 7 exhibited the strongest antioxidant activities. Treatment with D. viscosa extract and its fractions attenuates the increments of MDA, AST, ALT, ALP, GGT, total protein and increased GSH and SOD levels. The ethanol extract showed the most potent effect. The data confirmed the rationale for the traditional use of D. viscosa extracts to hepatic disorders. Further studies are needed in order to evaluate the isolated flavones as protective agents against liver injury and for their clinical application.

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هذه الصفحة هي خدمة مقدمة من جامعة الباحة - عمادة التعلم الإلكتروني وتقنية المعلومات لمنسوبي الجامعة من أعضاء هيئة التدريس والموظفين. جميع الآراء والمدخلات الواردة في هذه الصفحات تعبر عن رأي كاتبها فقط، ولا تعبر بالضرورة عن رأي جامعة الباحة.