With the idea of proposing solid state systems that have a high storage capacity of molecular hydrogen, a density functional theory study of magnesium oxide (MgO)_n clusters (n = 1–10) was carried out. Hydrogen–magnesium oxide systems presented adsorption energy values in accordance with the previously reported studies of physisorption processes; additionally negative values of ΔG_ads were found describing adsorption as a favorable process. Here, the (MgO)₇ cluster presented the highest adsorption energy. The storage capacity by weight of the magnesium oxide clusters was greater than the recommended percentage (7.5%) by the U.S. Department of Energy. QTAIM analysis and non-covalent index plots highlighted the weak nature of the interaction between the MgO clusters and hydrogen molecules, and the fundamental role of the Mg–O bonds’ polarity in the systems’ storage capacity.

The molecular dynamics and density functional theory (DFT) can be applied to discriminate electrocatalyst’s electron transfer (ET) properties. It will be interesting to discriminate the ET properties of green electrocatalysts such as amino acids. Here, we have used DFT to compare the electrocatalytic abilities of asparagine and glutamine at the carbon paste electrode interface. Cyclic voltammetric results reveal that the electrocatalytic activities of aspargine are higher than glutamine for dopamine sensing. Dopamine requires less energy to bind with asparagine when compared to glutamine. Additionally, asparagine has higher electron-donating and accepting powers. Therefore, asparagine has a higher electrocatalytic activity than glutamine—the ability for the asparagine and glutamine carbon electrodes to detect dopamine in commercial injection, and to obtain satisfactory results. As a part of the work, we have also studied dopamine interaction with the modified carbon surface using molecular dynamics.

Background: Annona muricata L. (guanabana) leaves are rich in bioactive compounds with potential antioxidant properties. In the state of Colima, both ethanolic extracts and infusions are traditionally used in folk medicine to address various ailments. This study aimed to evaluate and compare the phytochemical composition and antioxidant activities of ethanolic extracts and infusions of A. muricata leaves from three geographic regions in Colima, Mexico, with a focus on how geographic origin affects their bioactive properties. Methods: Ethanolic extracts and infusions were prepared from A. muricata leaves and analyzed using phytochemical screening; DPPH, total antioxidant capacity (TAC), and total phenolic content (TPC) measurements; and HPLC. TLC was also conducted to examine the presence of specific compounds, such as flavonoids and phenols. Results: Both the ethanolic extracts and infusions contained significant levels of alkaloids, flavonoids, tannins, and phenolic compounds. The infusions demonstrated superior antioxidant capacity, with DPPH inhibition values of 72.5%, 68.3%, and 65.1% in the northern, central, and southern regions, respectively, compared to the ethanolic extracts’ values of 50.3%, 48.9%, and 45.0%. HPLC identified quercetin as a major compound across all samples. Geographically, the northern region exhibited higher concentrations of bioactive compounds, particularly total flavonoid content (TFC) and iron-reducing power (FRPA). Conclusions: Both the ethanolic extracts and infusions of A. muricata leaves exhibited significant antioxidant properties, with the infusions showing superior performance. The results suggest that A. muricata infusions may have potential applications in managing oxidative stress-related diseases such as cancer and diabetes. Exploring their use in traditional medicine and employing this type of approach can help discern the metabolite profile responsible for these bioactivities. Geographic factors influence the bioactive profile of the plant, and further research is needed to isolate specific bioactive compounds and elucidate their therapeutic mechanisms.