One-pot regioselective synthesis and X-ray crystal structure of a stable [60]fullerene trisadduct with the e(edge),e(face),trans-1 addition pattern

The Bingel functionalisation of C(60) with a structurally novel tether equipped with three reactive malonate groups afforded a C(2v)-symmetrical e(edge),e(face),trans-1 trisadduct in a complete regioselective manner and in an excellent yield of 65%. The [60]fullerene trisadduct showed pronounced ability to crystallise and gave X-ray quality single crystals for analysis.     

Crocins from Crocus sativus L. in the Management of Hyperglycemia. In Vivo Evidence from Zebrafish

Diabetes mellitus is a disease characterized by persistent high blood glucose levels and accompanied by impaired metabolic pathways. In this study, we used zebrafish to investigate the effect of crocins isolated from Crocus sativus L., on the control of glucose levels and pancreatic β-cells. Embryos were exposed to an aqueous solution of crocins and whole embryo glucose levels were measured at 48 h post-treatment. We showed that the application of crocins reduces zebrafish embryo glucose levels and enhances insulin expression. We also examined whether crocins are implicated in the metabolic pathway of gluconeogenesis. We showed that following a single application of crocins and glucose level reduction, the expression of phosphoenolpyruvate carboxykinase 1 (pck1), a key gene involved in glucose metabolism, is increased. We propose a putative role for the crocins in glucose metabolism and insulin management.     

Biotechnological Approaches on Two High CBD and CBG Cannabis sativa L. (Cannabaceae) Varieties: In Vitro Regeneration and Phytochemical Consistency Evaluation of Micropropagated Plants Using Quantitative 1H-NMR

High cannabidiol (CBD) and cannabigerol (CBG) varieties of Cannabis sativa L., a species with medicinal properties, were regenerated in vitro. Explants of nodal segments including healthy axillary bud, after sterilization, were placed in Murashige-Skoog (MS) culture medium. The shoots formed after 30 days were subcultured in full- or half-strength MS medium supplemented with several concentrations of 6-benzyl-amino-purine (BA) or thidiazuron (TDZ). The highest average number and length of shoots was achieved when both full and half-strength MS media were supplemented with 4.0 μM BA. The presence of 4.0 μM TDZ showed also comparable results. BA and TDZ at concentrations of 4.0, 8.0 μM and 2.0, 4.0 μM respectively, displayed the maximum shooting frequency. The new shoots were transferred on the same media and were either self-rooted or after being enhanced with different concentrations of indole-3-butyric acid (IBA) or α-naphthalene acetic acid (NAA). Presence of 2.0 or 4.0 μM IBA or 4.0 μM NAA resulted to the optimum rooting rates. The maximum average number and length of roots per shoot was observed when the culture media was supplemented with 4.0 μM IBA or NAA. Approximately 92% of the plantlets were successfully established and acclimatized in field. The consistency of the chemical profile of the acclimatized in vitro propagated clones was assessed using quantitative ¹H-NMR high throughput screening. In each variety, analysis of the micropropagated plant in comparison with the mother plant showed no statistically significant differences (p ≤ 0.05) in CBD+ cannabidiolic acid (CBDA) and CBG+ cannabigerolic acid (CBGA) content respectively, thus indicating stability of their chemical profile.     

Flame-retarded hydrophobic cellulose through impregnation with aqueous solutions and supercritical CO2

We have developed flame-retarded hydrophobic cellulose-based materials by producing in situ water-soluble and insoluble inorganic microparticles on various surfaces of native cellulose (filter paper and pure cotton textile). The nanoparticles were produced by simple impregnation of cellulose with two different aqueous solutions followed by a third impregnation with supercritical CO₂. Finally, the composite cellulose materials were covered by a silicon-based polymer thin film, to turn it into hydrophobic and prevent the water-soluble particles from absorbing humidity. The obtained flame-retardant behaviour is due to a combination of mechanisms. The total treatment of cellulose has an impact on, both its surface morphology and its hydrophilicity. Thus, the hydrophobic nature of the silicon-based polymer film along with the roughness caused by the presence of the inorganic particles and the inherent roughness of native cellulose resulted in superhydrophobic behaviour. The same process-concept was also applied to regenerated (from newspaper) cellulose with ionic liquids. The produced materials were characterised by thermogravimetric analysis, differential scanning calorimetry, infrared spectroscopy, scanning electron microscopy and water contact angle measurements.     

Efficient hydrosilylation of carbonyl compounds by 1,1,3,3-tetramethyldisiloxane catalyzed by Au/TiO2

1,1,3,3-Tetramethyldisiloxane (TMDS) is a highly reactive reducing reagent in the Au/TiO₂-catalyzed hydrosilylation of carbonyl compounds relative to monohydrosilanes. The reduction of aldehydes or ketones with TMDS can be performed on many occasions at ambient conditions within short reaction times and at low loading levels of gold, whereas typical monohydrosilanes require excess heating and prolonged time for completion. The product yields are excellent, while almost stoichiometric amounts of carbonyl compounds and TMDS can be used. It is postulated that the enhanced reactivity of TMDS is attributed to the formation of a gold dihydride intermediate. This intermediate is also supported by the fact that double hydrosilylation of carbonyl compounds by TMDS is a negligible pathway.     

Effect of clay modification on structure–property relationships and thermal degradation kinetics of β-polypropylene/clay composite materials

Journal of Thermal Analysis and Calorimetry - The influence of neat and organically modified montmorillonite on the structure–property relationships of a β-nucleated polypropylene matrix...     

An Overview on Target-Based Drug Design against Kinetoplastid Protozoan Infections: Human African Trypanosomiasis,Chagas Disease and Leishmaniases

The protozoan diseases Human African Trypanosomiasis (HAT), Chagas disease (CD), and leishmaniases span worldwide and therefore their impact is a universal concern. The present regimen against kinetoplastid protozoan infections is poor and insufficient. Target-based design expands the horizon of drug design and development and offers novel chemical entities and potential drug candidates to the therapeutic arsenal against the aforementioned neglected diseases. In this review, we report the most promising targets of the main kinetoplastid parasites, as well as their corresponding inhibitors. This overview is part of the Special Issue, entitled “Advances of Medicinal Chemistry against Kinetoplastid Protozoa (Trypanosoma brucei, Trypanosoma cruzi and Leishmania spp.) Infections: Drug Design, Synthesis and Pharmacology”.     

Fine-tuning of the diffusion dimension of –OH groups for high resolution DOSY NMR applications in crude enzymatic transformations and mixtures of organic compounds

A convenient DOSY methodology was developed that can be applied directly in crude reaction products or mixtures containing polyphenol organic compounds, for the rapid identification of their various components without any prior separation or isolation. The method is based on the resolution enhancement of the resonances of the –OH protons and the fine-tuning of their diffusion coefficients to the molecular diffusion coefficient; this can be achieved in DMSO-d₆ in combination with the addition of picric acid and the use of temperatures near the freezing point of the solution. This method, which does not modify the apparent molecular diffusion, allowed the recording of high resolution DOSY spectra, both in crude enzymatic reactions and mixtures of organic compounds based on the phenolic OH NMR spectral region which is much less crowded and, thus, much more informative compared to the aromatic region.