Navegando por Autor "Carvalho, Alexandre Bizzotto de"
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Item Copper(II)/diiminic complexes based on 2-hydroxybenzophenones : DNA-and BSA-binding studies and antitumor activity against HCT116 and HepG2 tumor cells.(2023) Rodrigues, Júlia Helena Valadares; Carvalho, Alexandre Bizzotto de; Silva, Valdenizia Rodrigues; Santos, Luciano de Souza; Soares, Milena Botelho Pereira; Bezerra, Daniel Pereira; Oliveira, Katia Mara de; Correa, Rodrigo de SouzaHere, we report four new heteroleptic Cu(II) complexes with the formula [Cu(bipy)(2H4MeBz)]NO3 (1), [Cu (phen)(2H4MeBz)]NO3 (2), [Cu(bipy)(2H4OcBz)]NO3 (3) and [Cu(phen)(2H4OcBz)]NO3 (4), where the ligands are 2-hydroxy-4-methoxybenzophenone (2H4MeBz), 2-hydroxy-4-(octyloxy)benzophenone (2H4OcBz), 2,2′ - bipiridine (bipy) and 1,10-phenantroline (phen). All compounds present two bidentate ligands, a monoanionic 2- hydroxybenzophenone, forming a six-membered chelate ring and the diiminic ring forming a five-membered chelate ring, as well as one nitrate as counterion located at the axial position, as suggested by the crystal structure of complex 2. Complex/DNA interaction studies were also performed using spectroscopic titration (Kb close to 104 M− 1 ), viscosity, Hoechst 33258 competition, and circular dichroism, revealing a moderate interaction between them. Additionally, complexes 1–4 moderately interact with BSA (Bovine Serum Albumin). The compounds were evaluated against HCT116 (human colon carcinoma) and HepG2 (human hepatocellular carcinoma) cancer cells and against MRC-5 (human lung fibroblast), a noncancer cells. The cytotoxic results suggest that complexes 2 and 4 are more cytotoxic than 1 and 3, showing that the presence of phen ligand may play an important role in increasing the biological effect of the compounds.Item A new polymorph of six-coordinated bis(5,5′-dimethyl-2,2′-bipyridine) nitratocopper(II) nitrate and its DNA interactions.(2021) Gonçalves, Guilherme Resende; Carvalho, Alexandre Bizzotto de; Araujo Neto, João Honorato de; Oliveira, Katia Mara de; Correa, Rodrigo de SouzaHere, we present a new polymorph of the [Cu(5mebipy)(NO3)]NO3 complex (1, Form II), where 5mebipy means 5,5 -dimethyl-2,2 -bipyridine. The copper(II) complex 1 was characterized by spectroscopic techniques and single-crystal X-ray diffraction. The Form II presents a six-coordinated structure, meanwhile the Form I, previously reported, is five-coordinated with the nitrate ligand as monodentate. The molecular structures of both crystalline forms were compared based on intramolecular aspects using Kleywegt’s analysis and the intermolecular contacts evaluated by Hirshfeld surface studies. Moreover, the interaction of the complex [Cu(5mebipy)(NO3)]+ with CT-DNA was carried out using viscosity and spectrophotometric titrations, exhibiting a binding constant of 2.57 × 104 M − 1. This study contributes to explore the intra and intermolecular details of the new polymorph of the complex [Cu(5mebipy)(NO3)]NO3 and its capability to interacts with CT-DNA.Item Synthesis and molecular structure of a chiral bipyridine-menthol ether.(2020) Carvalho, Alexandre Bizzotto de; Diogo, Gabriela Maciel; Correa, Rodrigo de Souza; Taylor, Jason GuyThis paper presents the synthesis and structural characterization of 6,6′-bis[(1R,2S,5R)-isomenthoxy]-2,2′- bipyridine obtained by homocoupling of chiral pyridyl-ether 2-bromo-6-[(1R,2S,5R)-isomenthoxy]- pyridine. The two-step synthetic procedure afforded chiral bipyridine in a good yield and the structure of the compound is determined by X-ray diffraction. It crystallizes in a non-centrosymmetric chiral crystal structure type (P21, a = 10.7543(8) Å, b = 8.4488(6) Å, c = 15.8964(10) Å, β = 104.035(7)°, V = 1401.24(17) Å3 , Z = 2). Moreover, the compound is characterized by FTIR, high resolution mass spectrometry and its complexation capacity to transition metals is studied by UV-Vis spectroscopy.