A one-pot Biginelli synthesis of 3,4-dihydropyrimidin-2-(1H)-ones/thiones catalyzed by triphenylphosphine as Lewis base

We report herein the use of triphenylphosphine (TPP) as a new catalyst for the one-pot Biginelli reaction coupling of β-ketoesters, aldehydes and urea (or thiourea) to afford the corresponding dihydropyrimidinones/thiones.     

Regularity of solutions of Poisson’s equation in multiplier spaces

The most important result stated in this paper is to show that the solutions of the Poisson equation −Δu = f, where f ∈ (Ḣ¹(ℝ ^d ) → (Ḣ⁻¹(ℝ ^d )) is a complex-valued distribution on ℝ ^d , satisfy the regularity property D ^k u ∈ (Ḣ¹ → Ḣ⁻¹) for all k, |k| = 2. The regularity of this equation is well studied by Maz’ya and Verbitsky [12] in the case where f belongs to the class of positive Borel measures.      

Direct MALDI-MS analysis of cardiolipin from rat organs sections

Cardiolipins (CL) are mitochondria specific lipids. They play a critical role in ATP synthesis mediated by oxidative phosphorylation. Abnormal CL distribution is associated with several disease states. MALDI-MS and MALDI-MS/MS were used to demonstrate in situ analysis and characterization of CL from tissue sections of organs containing high concentrations of mitochondria. Once the experimental parameters were established, a survey of CL distribution in heart, liver, kidney, leg muscle, and testis was undertaken. The major CL specie in the heart muscle, leg muscle, liver, and kidney is the (18:2)(4) CL, while liver and kidney also contain a minor specie, (18:2)(3)/(18:1) CL. The major CL specie in testis is the (16:0)(4) CL. The CL species distribution in various organs appeared to be in agreement with prior reports. Overall, proper matrix selection, tissue section handling, instrument tuning, and the inclusion of cesium ion in matrix ensured successful in situ MALDI-MS and MALDI-MS/MS analysis of CL. Upon modification and standardization, this method could be streamlined for rapid pathological diagnosis with short turnaround time in clinical settings.     

In situ structural characterization of glycerophospholipids and sulfatides in brain tissue using MALDI-MS/MS

Lipids are major structural components of biomembranes. Negatively charged species such as phosphatidylinositol, phosphatidylserine, sulfatides, and the zwitterionic phosphatidylethanolamines are major components of the cytoplasmic surface of the cellular membrane lipid bilayer and play a key role in several receptors signaling functions. Lipids are not just involved in metabolic and neurological diseases; negatively charged lipids in particular play crucial roles in physiological events such as signal transduction, receptors, and enzymatic activation, as well as storage and release of therapeutic drugs and toxic chemicals in the body. Due to the importance of their role in signaling, the field of lipidomics has rapidly expanded in recent years. In the present study, direct probing of tissue slices with negative ion mode matrix assisted laser desorption/ionization mass spectrometry was employed to profile the distribution of lipids in the brain. In total, 32 lipid species consisting of phosphatidylethanolamines, phosphatidylglycerol, phosphatidylinositols, phosphatidylserines, and sulfatides were assigned. To confirm the structure of lipid species, MALDI-MS/MS analysis was conducted. Product-ion spectra obtained in negative ion mode allow for the assignment of the head groups and the fatty acid chains for the lipid species.     

Charge state effect on the zwitterion influence on stability of non-covalent interaction of single-stranded DNA with peptides

Negative ion ESI mass spectrometry was used to study the gas-phase stability and dissociation pathways of peptide-DNA complexes. We show that bradykinin and three modified peptides containing the basic residue arginine or lysine form stable interactions with single-stranded oligonucleotides. ESI-MS/MS of complexes of T(8) with PPGFSPFRR resulted in a major dissociation pathway through cleavage of the peptide covalent bond. The stability of the complex is due to electrostatic interaction between the negatively charged phosphate group and the basic side chain of the arginine and lysine residues as demonstrated by Vertes et al. and Woods et al. In fact, the present work establishes the role played by zwitterions on complex stabilisation. The presence of protons in nucleobase and/or amino acid contributes in reinforcing the strength of the salt bridge (SB) interaction. The zwitterionic form of the most basic of amino acid residues, arginine, is assumed to form a strong SB interaction to the negatively charged phosphate groups of DNA. This non-covalent complex is stable enough to withstand disruption of the non-covalent interaction and to first break the covalent bond. Moreover, the dependence of fragmentation patterns upon the complex charge state is explained by the fact that the net number of negative charges modulates the number of zwitterionic sites, which stabilise the complexes. Finally, the weak influence of the nucleobase is assumed by the existence of competition for proton addition between the nucleobase and the R/K side chain leading to a decrease in the stabilisation of the SB interaction.     

Oriental Hornet (Vespa orientalis) Larval Extracts Induce Antiproliferative,Antioxidant, Anti-Inflammatory,and Anti-Migratory Effects on MCF7 Cells

The use of insects as a feasible and useful natural product resource is a novel and promising option in alternative medicine. Several components from insects and their larvae have been found to inhibit molecular pathways in different stages of cancer. This study aimed to analyze the effect of aqueous and alcoholic extracts of Vespa orientalis larvae on breast cancer MCF7 cells and investigate the underlying mechanisms. Our results showed that individual treatment with 5% aqueous or alcoholic larval extract inhibited MCF7 proliferation but had no cytotoxic effect on normal Vero cells. The anticancer effect was mediated through (1) induction of apoptosis, as indicated by increased expression of apoptotic genes (Bax, caspase3, and p53) and decreased expression of the anti-apoptotic gene Bcl2; (2) suppression of intracellular reactive oxygen species; (3) elevation of antioxidant enzymes (CAT, SOD, and GPx) and upregulation of the antioxidant regulator Nrf2 and its downstream target HO-1; (4) inhibition of migration as revealed by in vitro wound healing assay and downregulation of the migration-related gene MMP9 and upregulation of the anti-migratory gene TIMP1; and (5) downregulation of inflammation-related genes (NFκB and IL8). The aqueous extract exhibited the best anticancer effect with higher antioxidant activities but lower anti-inflammatory properties than the alcoholic extract. HPLC analysis revealed the presence of several flavonoids and phenolic compounds with highest concentrations for resveratrol and naringenin in aqueous extract and rosmarinic acid in alcoholic extract. This is the first report to explain the intracellular pathway by which flavonoids and phenolic compounds-rich extracts of Vespa orientalis larvae could induce MCF7 cell viability loss through the initiation of apoptosis, activation of antioxidants, and inhibition of migration and inflammation. Therefore, these extracts could be used as adjuvants for anticancer drugs and as antioxidant and anti-inflammatory agents.     

Single, binary and multi-component adsorption of some anions and heavy metals on environmentally friendly Carpobrotus edulis plant

A low-cost adsorbent and environmentally friendly adsorbent from Carpobrotus edulis plant was used for the removal of NO(3)(-), H(2)PO(4)(-), Pb(2+) and Cd(2+) ions from single, binary and multi-component systems. The efficiency of the adsorbent was studied using batch adsorption technique under different experimental conditions by varying parameters such as pH, initial concentration and contact time. In single component systems, the dried C. edulis has the highest affinity for Pb(2+), followed by NO(3)(-), Cd(2+) and H(2)PO(4)(-), with adsorption capacities of 175mg/g, 125mg/g, 28mg/g and 26mg/g, respectively. These results showed that the adsorption of NO(3)(-) and H(2)PO(4)(-) ions from single and binary component systems can be successfully described by Langmuir and Freundlich isotherms. Freundlich adsorption model, showed the best fit to the single and binary experimental adsorption data. These results also indicated that the adsorption yield of Pb(2+) ion was reduced by the presence of Cd(2+) ion in binary metal mixture. The competitive adsorption of NO(3)(-), H(2)PO(4)(-), Pb(2+) and Cd(2+) ions on dried C. edulis plant shows that NO(3)(-) and H(2)PO(4)(-) anions are able to adsorb on different free binding sites and Pb(2+) and Cd(2+) cations are able to adsorb on the same active sites of C. edulis particles. The dried C. edulis was found to be efficient in removing nitrate, phosphate, cadmium and lead from aqueous solution as compared to other adsorbents already used for the removal of these ions.     

Response characteristics of lead-selective membrane sensors based on a newly synthesized quinoxaline derivatives as neutral carrier ionophores

Ionics - Novel lead-selective polymeric membrane sensors were prepared based on the use of 2,2′-(quinoxaline-2,3-diyl bis (azanediyl)) dibenzoic acid (sensor I) and...     

The optimum conditions for methanol conversion to dimethyl ether over modified sulfated zirconia catalysts prepared by different methods

Sulfated zirconia (SZ) and two promoted 1%Mn/SZ catalysts which have been prepared via sol gel (Mn/SZ-S) and impregnation (Mn/SZ-I) methods were studied.The morphology of the catalysts was characterized by XRD,BET,NH_3-TPD,ICP,SEM and FT-IR analysis.The conversion of methanol to dimethyl ether and hydrocarbons was carried out in the temperature range of 120-300 ℃.The Mn/SZ-S showed the highest activity due to the high surface area with suitable acidity.The optimum condition of Mn/SZ-S catalyst was investigated at 200°C and LHSV of 0.02 h~(-1) in a time range from 30 to 210 min.It was found that the total conversion decreased from 80.18% to 53.26% at 210 min.The reusability of this catalyst was studied at the optimum condition up till four cycles for 1 h.The characterization of the reused catalyst showed a significant change in the structure and surface acidity due to the blockage of the surface acid sited by carbonaceous materials.     

Encapsulation of β-Sitosterol in Polyurethane by Sol–Gel Electrospinning

Pristine β-sitosterol or in combination with other phytosterols is utilized in an array of enriched commercial foods. Considering the presence of β-sitosterol in different functional foods and its potential role in prevention and cure of neurodegenerative diseases, the aims of our investigation were to encapsulate β-sitosterol in nanofibers and to estimate influence of β-sitosterol on proliferation of fibroblasts. Electrospun nanofibers have widely been used as scaffolds to mimic natural extracellular matrix. Herein, our group for the first time establishes an innovative scaffold based on β-sitosterol and polyurethane using electrospinning. β-Sitosterol promotes epithelialization and possesses anti-oxidant and anti-inflammatory activities, whereas polyurethane, besides possessing biomedical uses, also enhances epithelial growth. We optimized the concentration (5%) of β-sitosterol in polyurethane to obtain homogenous solution, which can be spun without difficulty for the synthesis of β-sitosterol amalgamated scaffold. The resulted twisted nanofibers have been characterized via scanning electron microscopy and Fourier transform infrared spectroscopy. The viability of cells on twisted scaffold was examined using NIH 3T3 fibroblasts as model cell line. Incorporation of β-sitosterol in polyurethane changed the structure and size of nanofibers, and the twisted scaffolds were non-cytotoxic. Thus, the twisted nanoribbons, which contain anti-inflammatory β-sitosterol, can be utilized as a promising future material, which will help to ease inflammation and also aid in wound healing. In conclusion, the outcome of the preliminary research evidently points out the potential of twisted scaffold in biomedical applications.