Synthesis,structures and magnetic properties of three metal-organic frameworks containing manganese(II)

Two new Mn(II) coordination polymers formed with molecular formula [Mn(H₂O)₂(HBTC)·(H₂O)] 1 and [Mn(H₂O)₂(4,4′bipy)(HBTC)₂]·(H4,4′bipy)₂ 2, where BTC = 1,2,4-benzenetricarboxylate and 4,4′bipy = 4,4′bipydine, have been synthesized via hydrothermal approach and characterized by single crystal X-ray diffraction techniques. 1 is composed of Mn–H₂O–Mn 1D chains and further the chains are linked by HBTC ligands to form a 2D network in the ab plane; 2 is constructed by Mn–4,4′bipy–Mn 1D chains along the b direction with Mn²⁺ ions coordinated to H₂BTC and water as terminal ligands to form a 2D network. We also prepared a third compound with the molecular formula of [Mn(H₂O)(HBTC)·(H₂O)] which has been recently structurally reported elsewhere. The magnetic properties of the three compounds have been studied in detail under variable temperatures.     

Phenolic Compounds’ Occurrence in Opuntia Species and Their Role in the Inflammatory Process: A Review

Within the Cactaceae family, Opuntia comprises the most widespread species, with a recognized importance in human life, including feeding, domestic use as home natural barriers, and as a traditional remedy for diverse diseases and conditions such asthma, edema, and burns. Indeed, scientific reports have stated that these health benefits may be due to various active compounds, particularly polyphenols, which are ubiquitously found in plants and have proven their pharmacological efficiency by displaying antimicrobial, anti-cancer, and anti-inflammatory activities, among others. Opuntia species contain different classes of phenolic compounds that are recognized for their anti-inflammatory potential. Among them, quercetin, isorhamnetin, and kaempferol derivates were reported to greatly contribute to modulate cells’ infiltration and secretion of soluble inflammatory mediators, with key implications in the inflammatory process. In this review, we make a summary of the different classes of phenolic compounds reported in Opuntia species so far and explore their implications in the inflammatory process, reported by in vitro and in vivo bioassays, supporting the use of cactus in folk medicine and valorizing them from the socio-economic point of view.     

TiO2 Synthesis by the Pechini’s Method and Application for Diclofenac Photodegradation†

In this work, the effect of the calcination temperature on the TiO₂ synthesis using Pechini’s method was reported. The adopted calcination temperatures were 500, 600, and 700°C. XRD measurements indicated the composition of crystalline phases, and from there, the conversion of the anatase phase to rutile. TiO₂ Evonik^® was used as a reference standard and sodium diclofenac as a standard for photodegradation assessment. The average crystalline size increased. In both cases, this trend accompanied the increase in calcination temperature. The optical properties were performed using diffuse UV‐Vis reflectance. Results obtained indicated maximum absorption wavelength values more intense and displaced to the visible region. Also, the estimated band gap energy values decreased. The photocatalytic performance of TiO₂ samples was superior to the reference catalyst (TiO₂ Evonik^®). Especially in the first 10 minutes, the comparative photodegradation was up to approximately 58% higher. The photodegradation kinetic constants were also higher, and by comparison, up to approximately 73% higher. Toxicity measurements, using Artemias salina, also indicated similar decay behavior in the first 10 minutes, with a performance of up to approximately 60%.     

Insights on Molecular Characteristics of Hydrochars by 13C-NMR and Off-Line TMAH-GC/MS and Assessment of Their Potential Use as Plant Growth Promoters

Hydrochar is a carbon-based material that can be used as soil amendment. Since the physical-chemical properties of hydrochar are mainly assigned to process parameters, we aimed at evaluating the organic fraction of different hydrochars through ¹³C-NMR and off-line TMAH-GC/MS. Four hydrochars produced with sugarcane bagasse, vinasse and sulfuric or phosphoric acids were analyzed to elucidate the main molecular features. Germination and initial growth of maize seedlings were assessed using hydrochar water-soluble fraction to evaluate their potential use as growth promoters. The hydrochars prepared with phosphoric acid showed larger amounts of bioavailable lignin-derived structures. Although no differences were shown about the percentage of maize seeds germination, the hydrochar produced with phosphoric acid promoted a better seedling growth. For this sample, the greatest relative percentage of benzene derivatives and phenolic compounds were associated to hormone-like effects, responsible for stimulating shoot and root elongation. The reactions parameters proved to be determinant for the organic composition of hydrochar, exerting a strict influence on molecular features and plant growth response.     

Ultra-high-performance liquid chromatography using a fused-core particle column for fast analysis of propolis phenolic compounds

Propolis is a bee product with a complex chemical composition formed by several species from different geographical origins. The complex propolis composition requires an accurate and reproducible characterization of samples to standardize the quality of the material sold to consumers. This work developed an ultra-high-performance liquid chromatography with a photodiode array detector method to analyze propolis phenolic compounds based on the two key propolis biomarkers, Artepillin C and p-Coumaric acid. This choice was made due to the complexity of the sample with the presence of several compounds. The optimized method was hyphenated with mass spectrometry detection allowing the detection of 23 different compounds. A step-by-step strategy was used to optimize temperature, flow rate, mobile phase composition, and re-equilibration time. Reverse-phase separation was achieved with a C18 fused-core column packed with the commercially available smallest particles (1.3 nm). Using a fused-core column with ultra-high-performance liquid chromatography allows highly efficient, sensitive, accurate, and reproducible determination of compounds extracted from propolis with an outstanding sample throughput and resolution. Optimized conditions permitted the separation of the compounds in 5.50 min with a total analysis time (sample-to-sample) of 6.50 min.