Choroba, K, Machura B, Kula S, Raposo LR, Fernandes AR, Kruszynski R, Erfurt K, Shul'pina LS, Kozlov YN, Shul'pin GB.
2019.
Copper(ii) complexes with 2,2':6',2''-terpyridine, 2,6-di(thiazol-2-yl)pyridine and 2,6-di(pyrazin-2-yl)pyridine substituted with quinolines. Synthesis, structure, antiproliferative activity, and catalytic activity in the oxidation of alkanes and alcohols, 2019. Dalton Trans. 48(33):12656-12673.
AbstractA series of 2,2':6',2''-terpyridine (terpy), 2,6-di(thiazol-2-yl)pyridine (dtpy) and 2,6-di(pyrazin-2-yl)pyridine (dppy) derivatives with n-quinolyl substituents (n = 2 and 4) was used to synthesize five-coordinate complexes [CuCl2(n-quinolyl-terpy)] (1-2), [CuCl2(n-quinolyl-dtpy)] (3-4) and [CuCl2(n-quinolyl-dppy)] (5-6), respectively. The main emphasis of the research was to investigate the impact of the triimine skeleton (terpy, dtpy and dppy) and n-quinolyl pendant substituent on the antiproliferative and catalytic properties of 1-6. The obtained Cu(ii) compounds were studied as antiproliferative agents against human colorectal (HCT116) and ovarian (A2780) carcinoma, and they were used as catalysts for the oxidation of alkanes and alcohols with peroxides under mild conditions. The kinetic characteristics of the oxidizing species generated by the catalytic system Cu(ii) complex-H2O2 in CH3CN were obtained from the dependence of the alkane oxidation rate on its initial concentration. A model of competitive interaction of hydroxyl radicals with CH3CN and RH in the catalyst cavity has been proposed which is based on the simultaneous study of kinetics and selectivity in alkane oxidations.
Kourmentza, C, Araujo D, Sevrin C, Roma-Rodriques C, Lia Ferreira J, Freitas F, Dionisio M, Baptista PV, Fernandes AR, Grandfils C, Reis MAM.
2019.
Occurrence of non-toxic bioemulsifiers during polyhydroxyalkanoate production by Pseudomonas strains valorizing crude glycerol by-product, 2019. Bioresour Technol. 281:31-40.
AbstractWhile screening for polyhydroxyalkanoate (PHA) producing strains, using glycerol rich by-product as carbon source, it was observed that extracellular polymers were also secreted into the culture broth. The scope of this study was to characterize both intracellular and extracellular polymers, produced by Pseudomonas putida NRRL B-14875 and Pseudomonas chlororaphis DSM 50083, mostly focusing on those novel extracellular polymers. It was found that they fall into the class of bioemulsifiers (BE), as they showed excellent emulsion stability against different hydrocarbons/oils at various pH conditions, temperature and salinity concentrations. Cytotoxicity tests revealed that BE produced by P. chlororaphis inhibited the growth of highly pigmented human melanoma cells (MNT-1) by 50% at concentrations between 150 and 200mug/mL, while no effect was observed on normal skin primary keratinocytes and melanocytes. This is the first study reporting mcl-PHA production by P. putida NRRL B-14785 and bioemulsifier production from both P. putida and P. chlororaphis strains.
Choroba, K, Machura B, Raposo LR, Malecki JG, Kula S, Pajak M, Erfurt K, Maron AM, Fernandes AR.
2019.
Platinum(ii) complexes showing high cytotoxicity toward A2780 ovarian carcinoma cells, 2019. Dalton Trans. 48(34):13081-13093.
Abstract2,6-Bis(thiazol-2-yl)pyridines functionalized with 9-anthryl (L(1)), 9-phenanthryl (L(2)), and 1-pyrenyl (L(3)) groups were used for the preparation of [Pt(L(n))Cl]CF3SO3 (1-3). The constitution of the Pt(ii) complexes was determined by (1)H and (13)C NMR spectroscopy, HR-MS spectrometry, elemental analysis and X-ray analysis (for (1)). The electrochemical and photophysical properties of [Pt(L(n))Cl]CF3SO3 were compared with the behaviour of the Pt(ii) complexes with aryl-substituted 2,2':6',2''-terpyridine ligands. What is noteworthy is that the coordination ability of dtpy toward the Pt(ii) centre was investigated for the first time. All complexes were tested in vitro by MTS assay on four tumor cell lines, A2780 (ovarian carcinoma), HTC116 (colon rectal carcinoma), MCF7 (breast adenocarcinoma), and PC3 (prostate carcinoma) and on normal primary fibroblasts. Compounds (1-3) showed a dose dependent antiproliferative effect in the A2780 cell line with (3) > (2) > (1) and this loss of A2780 cell viability was due to a combination of an apoptotic cell death mechanism via mitochondria and autophagic cell death. Exposure to IC50 concentration of (2) induced an increase in the number of apoptotic nuclei and a depolarization of the mitochondrial membrane which is consistent with the induction of apoptosis while exposure to IC50 concentration of (3) showed an increase in the apoptotic nuclei with a slight hyperpolarization of the mitochondrial membrane that might indicate an initial step of apoptosis induction. The complexes (2) and (3) induce an increase in the production of intracellular ROS which is associated with the trigger of the apoptotic pathways. The ROS production was augmented by the presence of oxidants and correlated with an increase of oxygen radicals. The IC50 of (2) and (3) (4.4 muM and 2.9 muM, respectively) was similar to the IC50 of cisplatin (3.4 muM) in the A2780 cell line, which together with their low cytotoxicity in normal fibroblasts, demonstrates their potential for further studies.