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- Facile synthesis of oxo-/thioxopyrimidines and tetrazoles C–C linked to sugars as novel non-toxic antioxidant acetylcholinesterase inhibitorsPublication . Figueiredo, J.A.; Ismael, M.I.; Pinheiro, J.M.; Silva, A.M.S.; Justino, Jorge; Silva, Filipa V.M.; Goulart, Margarida; Mira, D.; Araújo, M.E.M.; Campoy, R.; Rauter, A.P.Microwave-assisted synthesis of oxo-/thioxopyrimidines and tetrazoles linked to furanoses with D-xylo and D-ribo configuration, and to a D-galacto pyranose is reported and compared to conventional methods. Reaction of dialdofuranoses and dialdopyranoses with a b-keto ester and urea or thiourea under micro wave irradiation at 300 W gave in 10 min the target molecules containing the 2-oxo- or 2-thioxo-pyrimidine ring in high yield. The tetrazole-derived compounds were obtained in two steps by reaction of the formyl group with hydroxylamine hydrochloride, copper sulfate, triethylamine and dicyclohexylcarbodiimide to give an intermediate nitrile, which was then treated with sodium azide. The use of microwave irradiation in the latter step also resulted in a considerably shorter reaction time (10 min) compared to hours under conventional heating to obtain a complete starting materials conversion. Acetylcholinesterase inhibition ranged from 20% to 80% for compounds concentration of 100 lg/mL, demonstrating the potential of this family of compounds for the control of Alzheimer’s disease symptoms. Most of the compounds showed antioxidant activity in the b-carotene/linoleic acid assay, some of them exhibiting IC50 values in the same order of magnitude as those of gallic acid. The bioactive compounds did not show cytotoxic effects to human lymphocytes using the MTT method adapted for non-adherent cells, nor geno toxicity determined by the short-term in vitro chromosomal aberration assay.
- Pós-colheita em batataPublication . Silva, Filipa V.M.; Amaral, A.
- Sugar bislactones by one-step oxidative dimerisation with pyridinium chlorochromate versus regioselective oxidation of vicinal diolsPublication . Rauter, A. P.; Piedade, F.; Almeida, T.; Ramalho, R.; Ferreira, M.J.; Resende, R.; Amado, J.; Pereira, H.; Justino, Jorge; Neves, Ana; Silva, Filipa V.M.; Canda, T.Synthesis of 10-membered bislactones by PCC oxidation of methyl 2,6-di-O-pivaloyl-α-D-glucopyranoside and methyl 4,6-O-benzylidene-α-D-glucopyranoside is described, with emphasis on their structure elucidation using the information gained by combination of NMR spectroscopic techniques with X-ray diffraction data. In alternative, the use of PCC and PCC adsorbed on silica gel or alumina for the regioselective oxidation of vicinal diols in sugars is also reported. Both bislactones showed antifungal activity against Candida albicans, and were slightly active against the bacteria Bacillus subtilis. The bislactone presenting pivaloyl protecting groups also promoted some growth inhibition of Staphylococcus aureus.
- Cuidados pós-colheita em cebolaPublication . Silva, Filipa V.M.; Amaral, A.
- Perdas na conservação de batata para indústriaPublication . Amaral, A.; Silva, Filipa V.M.
- Alicyclobacillus acidoterrestris spores in fruit products and design of pasteurization processesPublication . Silva, Filipa V.M.; Gibbs, P.Alicyclobacillus acidoterrestris is a thermoacidophilic, nonpathogenic and sporeforming bacterium which has been found in commercial pasteurized fruit juices in the past. Only few and recent studies were available in the literature, since only in 1984 Cerny et al. [Cerny, G., Hennlich, W., & Poralla, K. (1984). Fruchtsaftverderb durch bacillen: isolierung und charakterisierung des verderbserregers. Z. Lebensmitt. Unters. Forsch. 179, 224-227] reported a spoiled aseptically packaged apple juice with A. acidoterrestris and in 1987 Deinhard et al. [Deinhard, G., Blanz, P., Poralla, K., & Altan, E. (1987). Bacillus acidoterrestris sp. nov., a new thermotolerant acidophile isolated from different soils. Systematic and Applied Microbiology, 10, 47-53] named first this species. Detection and identification methods for A. acidoterrestris were reviewed and data regarding heat resistance of spores and growth in fruits were collected. Finally, a new methodology to design pasteurization processes for high acidic fruit products is presented.