Selective Extraction Process and Characterization of Antioxidant Phenolic Compounds from Pereskia aculeata Leaves Using UPLC-ESI-Q-TOF-MS/MS.

This study innovates in comparing biological activities and chemical composition obtained from extracts and fractions from Pereskia aculeate leaves. Seven extracts and five fractions were produced by conventional successive solid-liquid extraction coupled with simultaneous bioguided purification using solvents of distinct polarities. A comparative analysis was conducted between these purified fractions and the original extracts to elucidate potential improvements in the bioactivity. The extract and fractions were evaluated using the ABTS, DPPH, FRAP, and Folin-Ciocalteau methods and HPLC-DAD and UHPLC-ESI-Q-TOF-MS/MS evaluated chemical composition. The fractions obtained from the hydroalcoholic extract showed better results, with the acetone fraction (Fr-Ace) exhibiting enhanced bioactivity, especially in the FRAP (1095 µmol of FeSO4/g) antioxidant capacity method. The results demonstrated that medium to high polarity solvents were the most effective in extracting bioactive phenolic compounds, with rutin being the predominant compound. The sequential hydroalcoholic fractionation (SHF) method extracted a greater variety of compounds, including vanillic acid and cinnamic acid, which were reported for the first time in P. aculeate leaves. The identified compounds by UPLC-Q-TOF-MS/MS included flavonoids derived from quercetin, isorhamnetin, and kaempferol, phenolic acids, and their derivatives. Quercetin-3-O-xyloside, kaempferol-3-O-arabinoside, trehalose, feruloyltyramine, malyngic acid, pinellic acid, and 16-hydroxy-9-oxooctadeca-10,12,14-trienoic acid were identified for the first time in P. aculeata leaves.

TiO2NTs bio-inspired coatings: revisiting electrochemical, morphological, structural, and mechanical properties.

By altering some synthesis variables, the morphology and structural properties of anodic TiO2nanotube arrays (TiO2NTs) can be tailored to a specific application. This study aims to investigate the effect of electrolyte-containing ions from human plasma and annealing temperature on structural, morphological, and mechanical parameters of TiO2NTs films, targeting its potential biomedical applications. Bio-inspired TiO2NTs were grown from Ticpand its Ti6Al4V alloy by potentiostatic anodization in the recently developed SBF-based electrolyte, maintained at 10 °C and 40 °C. The thermal investigation was performed by TGA/DSC and used to define the phase transition temperatures used for annealing (450 °C and 650 °C). Morphological and structural parameters were evaluated by FE-SEM, XRD, contact angle measurements, and nanoindentation. Results show that self-organized as-formed TiO2NTs were grown under all synthesis conditions with different wettability profiles for each substrate group. At 450 °C annealing temperature, the beginning of nanostructures collapse starts, becoming evident at 650 °C. The nanoindentation characterization reveals that both electrolyte and thermal annealing exhibited low effects on the hardness and Young's modulus. The tailoring of specific properties by different synthesis conditions could allow the individualization of treatments and better performancein vivo.

The Use of Anodic Oxides in Practical and Sustainable Devices for Energy Conversion and Storage.

This review addresses the main contributions of anodic oxide films synthesized and designed to overcome the current limitations of practical applications in energy conversion and storage devices. We present some strategies adopted to improve the efficiency, stability, and overall performance of these sustainable technologies operating via photo, photoelectrochemical, and electrochemical processes. The facile and scalable synthesis with strict control of the properties combined with the low-cost, high surface area, chemical stability, and unidirectional orientation of these nanostructures make the anodized oxides attractive for these applications. Assuming different functionalities, TiO2-NT is the widely explored anodic oxide in dye-sensitized solar cells, PEC water-splitting systems, fuel cells, supercapacitors, and batteries. However, other nanostructured anodic films based on WO3, CuxO, ZnO, NiO, SnO, Fe2O3, ZrO2, Nb2O5, and Ta2O5 are also explored and act as the respective active layers in several devices. The use of AAO as a structural material to guide the synthesis is also reported. Although in the development stage, the proof-of-concept of these devices demonstrates the feasibility of using the anodic oxide as a component and opens up new perspectives for the industrial and commercial utilization of these technologies.