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Immobilization systems more frequently used are calcium alginate spheres. These biocatalysts have many potential applications in the immobilization of enzymes, prokaryotic cells, vegetal and animal cells, algae, organelles and mixtures of these living components. Other applications of immobilized cells imply the use of non aqueous systems. Some bioconversions are carried out in the presence of solvents such as hexane acetone or acetonitrile, or mixtures water-solvents. The aim of this work was to investigate the behaviour of Ca-alginate spheres when put in contact with different solvents (water, diesel, ethanol, methanol, acetone, n-hexane, isopropyl alcohol, THF, acetonitrile, and toluene), or solvent-water mixtures (i.e., ethanol-water), regarding the resistance of the alginate spheres after days of contact. Calcium alginate particles suffered different damages, depending on the solvent they were put in contact. Water did not damaged the Ca-alginate structure with or without Ca present. On the other hand different solvents lost a proportion of volume, i.e., n-hexane (16%), methanol (19%), ethanol (19.5%), toluene (22%), diesel (34%), acetone (765), isopropyl alcohol (80%), THF and acetonitrile (total loss, total destruction). Nor the dielectric constant nor the polarity indexes were capable of explaining the difference on the volume loss or total sphere destruction, except for water-ethanol mixtures
Ozonated oils have demonstrated promising results for clinical applications. The reaction of ozone with the unsaturated compounds of oils produces by‐products such as ozonides and poly peroxides. A deeper knowledge of the dynamics of by‐product formation is helpful in determining the required ozonation degree to obtain therapeutic effects. The aim of this paper is to show the relationship between ozonation degree and structural and viscosity changes during the ozonation of grape seed (GS) and sunflower (SF) oils. Structural characterization was done by Fourier transform infrared (FT‐IR) and hydrogen‐1 nuclear magnetic resonance (1H NMR) spectroscopy, with iso‐ozonides being identified. Viscosity showed a significant increase during ozonation, a fact associated with poly peroxide formation. We have made use of the total unsaturation (TU) method to measure the ozonation degree. The TU of non‐ozonated GS oil was found to be higher than for SF oil (5.94 and 4.49 mmol per g of oil, respectively), and their by‐product distributions were also found to differ. In GS oil, three reaction steps were observed for double‐bond conversion into iso‐ozonides and poly peroxides, while the ozonides and poly peroxides were formed in parallel in SF oil. The studies we implemented characterized the differences in the reactivities of these oils with ozone. Practical applications: In this work, we propose using the TU method to measure the ozonation degree of ozonated oils. TU experimental determination is based on the ozonation of the sample, and the ozone‐oxidizable substrate is quantified. Despite GS and SF oils having similar fatty acid compositions, they contain other unsaturated compounds specific to their vegetal sources. These compounds are also reactive with ozone, and are also quantified by the TU method. The differences in distributions of by‐products among ozonated oils from different sources could explain why the ozonation degree need not be the same for different oils. Studies like this represent a feasibility foundation for controlling the therapeutic application of ozonated oils and correctly interpreting their well‐known clinical effects. Ozonated vegetable oils have many interesting applications in the food, cosmetic, and pharmaceutical industries, as well as in medicine. A deeper knowledge of the dynamics of by‐product formation is helpful in determining the required ozonation degree to obtain therapeutic effects. In this work, we propose using the total unsaturation method to measure the ozonation degree of ozonated oils. We showed the relationship between ozonation degree and structural and viscosity changes during the ozonation of grape seed and sunflower oils. The differences in distributions of by‐products among ozonated oils from different sources could explain why the ozonation degree need not be the same for different oils.
A hetero-trisaccharide resin glycoside of jalapinolic acid known as tricolorin F has been synthesized. The approach involved the preparation of intermediate 5 and a subsequent coupling reaction with imidate 6 to produce disaccharide 7, which after deacetylation generated intermediate 8. A further coupling between this glycosyl acceptor and the quinovose glycosyl donor 9 resulted in the formation of the tricoloric acid C derivative 10. Basic hydrolysis afforded the intermediate 11, which was subsequently lactonized under Yamaguchi conditions to produce protected macrolactone 12. Removal of acetonide and benzyl protecting groups afforded pure tricolorin F (1).
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