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Item The binding of 4-ethylguaiacol with polyaniline-based materials in winesAutores: Marican, A.; Carrasco-Sanchez, V.; John, A.; Laurie, VF.; Santos, LS.4-ethylguaiacol (4-EG) is one of the important compounds responsible for the "Brett character" (i.e. spicy and smoky aromas) found in wines contaminated with Brettanomyces yeast. In this trial, the ability of polyaniline-based materials (PANI-EB and PANI-ES) was tested as a potential fining agent for the removal of 4-EG in wine. First, a screening study was developed in order to determine the binding capacity of 4-EG by PANI materials in 12% ethanol solution. Then, the capturing ability of PANI against 4-EG was evaluated with a solution containing gallic acid (GA), 4-methyl-catechol (4-MC), in which the concentration of the phenolic compounds were maintained as in the real wine. The results obtained showed that the retention percentage varied between 0 to 100% (4-EG), 13.81% to 72.32% (GA), and 0 to 17.39% (4-MC), depending on the interaction time and amount of the PANI used. Finally, the capturing capacity of PANI-EB and PANI-ES against 4-EG was evaluated in a real wine sample containing originally 3.10 +/- 0.13 mg L-1 of 4-EG and 2.55 +/- 0.10 g L-1 of other total phenolic compounds. The analyses performed indicated that PANI-EB is more effective in removing 4-EG than PANI-ES, with retention percentages varying between 36 and 50%. (C) 2014 Elsevier Ltd. All rights reserved.Item Asymmetric total synthesis of TofacitinibAutores: Marican, A.; Simirgiotis, M.J.; Santos, L.S.Abstract: A novel stereoselective synthesis of Tofacitinib (CP-690,550), a Janus tyrosine kinase (JAK3) specific inhibitor, has been achieved starting from (5S)-5-hydroxypiperidin-2-one in 10 steps from 2 with a 9.5% overall yield. The potentiality of this synthetic route is the obtention of tert-butyl-(3S,4R)-3-hydroxy-4-methylpiperidine-1-carboxylate (6b) as a new chiral precursor involved in the synthesis of CP690,550, in a three-step reaction, without epimerizations, rather than the 5 or more steps used in described reactions to achieve this compound from analogues of 6b. (C) 2013 Elsevier Ltd. All rights reserved.
