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Introduction: Erythrina subumbrans, a medical plant found in sub-Saharan Africa and the Western Ghats of India, shows promise as a potential source of bioactive compounds to treat cancer. In our ongoing research on folk medical plants, we report the isolation of flavonoid compound from the stem bark of E. subumbrans along with its cytotoxic activity against breast cancer (MCF-7 and T47D), and cervical cancer (HeLa) cell lines. Purpose: This study aimed to isolate secondary metabolite from the stem bark of E. subumbrans and evaluate its cytotoxic activity to support the use of folk medicinal plants as alternative therapy against cancer. Methods: Isolupalbigenin was isolated from the stem bark of E. subumbrans by column chromatography. Cytotoxic activity against breast cancer (MCF-7 and T47D) and cervical cancer (HeLa) cell lines was evaluated using the MTT assay, whereas the in silico study was evaluated using molecular docking and molecular dynamics against estrogen receptor alpha (ERα). Results: The cytotoxic assay showed that isolupalbigenin inhibited the growth of MCF-7 cell with an IC50 of 31.62 µgâmL-1, while showing no toxicity against normal human cells (Vero cell line). The molecular docking results suggested that isolupalbigenin can bind to ERα with a lower binding affinity than estradiol, whereas the stability of the isolupalbigenin-ERα complex was confirmed by molecular dynamic simulation with a median Root Mean Square Deviation (RMSD) of 2.80 Å. Toxicity prediction suggested that isolupalbigenin was less likely to cause hepatotoxicity or carcinogenicity, whereas pharmacokinetic prediction suggested that isolupalbigenin has high intestinal absorption with medium Caco2 permeability. In addition, isolupalbigenin was predicted to have a medium volume of distribution (Vd). Conclusion: Isolupalbigenin isolated from the stem bark of E. subumbrans with cytotoxic activity supports further development of plants from the genus Erythrina as a medicinal plant for alternative therapy against cancer.
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The depletion of fossil fuels is a worldwide problem that has led to the discovery of alternative energy sources. Solar energy is the focus of numerous studies due to its huge potential power and environmentally friendly nature. Furthermore, one such area of study is the production of hydrogen energy by engaging photocatalysts using the photoelectrochemical (PEC) method. 3-D ZnO superstructures are extensively explored, showing high solar light-harvesting efficiency, more reaction sites, great electron transportation, and low electron-hole recombination. However, further development requires the consideration of several aspects, including the morphological effects of 3D-ZnO on water-splitting performance. This study reviewed various 3D-ZnO superstructures fabricated through different synthesis methods and crystal growth modifiers, as well as their advantages and limitations. Additionally, a recent modification by carbon-based material for enhanced water-splitting efficiency has been discussed. Finally, the review provides some challenging issues and future perspectives on the improvement of vectorial charge carrier migration and separation between ZnO as well as carbon-based material, using rare earth metals, which appears to be exciting for water-splitting.
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ZnO photoanodes in photoelectrochemical (PEC) water splitting for green-hydrogen production are limited due to the large bandgap that is only confined to UV light. One of the strategies for broadening the photo absorption range and improving light harvesting is to modify a one-dimensional (1D) nanostructure to a three-dimensional (3D) ZnO superstructure coupling with a narrow-bandgap material, in this case, a graphene quantum dot photosensitizer. Herein, we studied the effect of sulfur and nitrogen co-doped graphene quantum dot (S,N-GQD) sensitization on the surface of ZnO nanopencil (ZnO NPc) to give a photoanode in the visible light spectrum. In addition, the photo energy harvesting between the 3D-ZnO and 1D-ZnO, as represented by neat ZnO NPc and ZnO nanorods (ZnO NRs), was also compared. Several instruments, including SEM-EDS, FTIR, and XRD revealed the successful loading of S,N-GQDs on the ZnO NPc surfaces through the layer-by-layer assembly technique. The advantages are S,N-GQDs's band gap energy (2.92 eV) decreasing ZnO NPc's band gap value from 3.169 eV to 3.155 eV after being composited with S,N-GQDs and facilitating the generation of electron-hole pairs for PEC activity under visible light irradiation. Furthermore, the electronic properties of ZnO NPc/S,N-GQDs were improved significantly over those of bare ZnO NPc and ZnO NR. The PEC measurements revealed that the ZnO NPc/S,N-GQDs stood out with a maximum current density of 1.82 mA cm-2 at +1.2 V (vs. Ag/AgCl), representing a 153% and 357% improvement over the bare ZnO NPc (1.19 mA cm-2) and the ZnO NR (0.51 mA cm-2), respectively. These results suggest that ZnO NPc/S,N-GQDs could have potential for water splitting applications.
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An integrated biorefinery approach using spent industrial ginger waste for resource recovery is reported. Valuable products including ginger oil, starch, microfibrillated cellulose (MFC), bio-oil and hydrochar were obtained. Approximately 4 % ginger oil, with a profile similar to commercial ginger oil, can be recovered via Soxhlet or Supercritical CO2 + 10 %EtOH extraction. The oil-free ginger residues were processed using two microwave techniques: starch, MFC and sugar-rich hydrolysates were firstly gained through hydrothermal microwave processing (120-200 °C in water alone), whilst chemical-rich bio-oils and energy-dense hydrochar (20-24.5 MJ kg-1) were obtained via conventional microwave pyrolysis (220-280 °C). The ginger MFC exhibited increased propensity to form microfibrillated cellulose (as evidenced by Transmission Electron Microscopy) with increasing temperature. Nanocrystalline cellulose was produced at the highest processing temperature (200 °C). These changes are commensurate with the leaching and decomposition of the amorphous regions within cellulose. The molecules and materials isolated have further downstream applications and, thus, compared to current low value resolution methods (dumping, burning or animal feed), spent industrial ginger waste is a significant resource for consideration within a biorefinery concept.