Browsing by Author "Ferreira, Susana"
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- Antimicrobial and antitumor activity of S-methyl dithiocarbazate Schiff base zinc(II) complexesPublication . Ramilo-Gomes, Filipa; Alemu, Yemataw; Tekamo, Israel; Cavaco, Isabel; Campos, Débora L.; Pavan, Fernando R.; Gomes, Clara S.B.; Brito, Vanessa; Santos, Adriana O.; Domingues, Fernanda; Luís, Ângelo; Marques, M. Matilde; Pessoa, João Costa; Ferreira, Susana; Silvestre, Samuel; Correia, IsabelSchiff bases (SB) obtained from S-methyl dithiocarbazate and aromatic aldehydes: salicylaldehyde (H2L1), o-vanillin (H2L2), pyridoxal (H2L3) and 2,6-diformyl-4-methylphenol (H3L4), and their corresponding Zn(II)-complexes (1-4), are synthesized. All compounds are characterized by elemental analyses, infrared, UV-Vis, nuclear magnetic resonance spectroscopy and mass spectrometry. The structures of H2L2 and [Zn2(L1)2(H2O)(DMF)] (1a) (DMF = dimethylformamide) are solved by single crystal X-ray diffraction. The SB coordinates the metal center through the Ophenolate, Nimine and Sthiolate atoms. The radical scavenging activity is tested using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, with all ligand precursors showing IC50 values ~40 μM. Cytotoxicity studies with several tumor cell lines (PC-3, MCF-7 and Caco-2) as well as a non-tumoral cell line (NHDF) are reported. Interestingly, 1 has relevant and selective antiproliferative effect against Caco-2 cells (IC50 = 9.1 μM). Their antimicrobial activity is evaluated in five bacterial strains (Klebsiella pneumoniae, Acinetobacter baumannii, Listeria monocytogenes, Pseudomonas aeruginosa and Staphylococcus aureus) and two yeast strains (Candida albicans and Candida tropicalis) with some compounds showing bacteriostatic and fungicidal activity. The minimal inhibitory concentration (MIC90) of HnL against Mycobacterium tuberculosis is also reported, with H2L2 and H3L4 showing very high activity (MIC90 < 0.6 μg/mL). The ability of the compounds to bind bovine serum albumin (BSA) and DNA is evaluated for H3L4 and [Zn2(L4)(CH3COO)] (4), both showing high binding constants to BSA (ca. 106 M-1) and ability to bind DNA. Overall, the reported compounds show relevant antitumor and antimicrobial properties, our data indicating they may be promising compounds in several fields of medicinal chemistry.
- Effect of temperature on the daily increment deposition in the Otoliths of European sardine Sardina pilchardus (Walbaum, 1792) LarvaePublication . Soares, Claudia; Ferreira, Susana; Ré, Pedro; Teodosio, Maria Alexandra; Santos, António Miguel; Batista, Hugo; Baylina, Nuria; Garrido, SusanaOtolith microstructure analysis is a valuable tool to evaluate the relationship between larval age and growth and how it relates to environmental variability. Otolith growth and daily increment deposition were analyzed in sardine (Sardina pilchardus) larvae reared in the laboratory under different temperatures (13, 15, and 17 ◦C), with a diet rich in microalgae, rotifers, and copepods Acartia grani. The number and width of growth increments, first-check and otolith diameter were determined in the otoliths and then related to larval age and total length. At hatching, the sagittal otoliths consisted of a lenticular core with a diameter of 10.56 µm (±1.07 µm SD). Somatic growth increased with the increasing temperature and the growth rate of larvae reared at 13 and 15 ◦C was significantly lower than for larvae reared at 17 ◦C. At 17 ◦C, otoliths exhibited a higher diameter with wider increments than at 13 ◦C. There was a high variability of increment counts-at-age for larvae reared within the same temperature treatment. The increase of growth increments with larval size was higher for larvae reared at 17 ◦C until 35 days post-hatching than those growing at 15 ◦C. Scanning electronic microscopy confirmed that increments are deposited daily, with an average width smaller than 1 µm and as low as 0.33 µm, therefore impossible to distinguish using light microscopy. At colder temperatures, larval otoliths had thinner and less marked increments and lower growth rates, which can lead to incorrect age determinations. The effect of temperature on the otolith microstructure can help in identifying strong temperature gradients experienced by wild sardine larvae.
- Sardine validation temperatures - data supporting results published in "Effect of temperature on the daily increment deposition in the Otoliths of European Sardine Sardina Pilchardus (Walbaum, 1792) Larvae". OceansPublication . Soares, Claúdia; Ferreira, Susana; Ré, Pedro; Teodosio, Maria Alexandra; Santos, A. M. P.; Batista, Hugo; Baylina, Nuria; Garrido, SusanaSardine Validation Temperatures - dataset supporting results published in Effect of Temperature on the Daily Increment Deposition in the Otoliths of European Sardine Sardina Pilchardus (Walbaum, 1792) Larvae. Oceans. Samples where collected at the Oceanário de Lisboa, in 2010 and analysed in the Instituto Português do Mar e da Atmosfera.