Person:
Repetto, Guillermo

Profesor/a Titular de Universidad
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First Name
Guillermo
Last Name
Repetto
Affiliation
Universidad Pablo de Olavide
Department
Biología Molecular e Ingeniería Bioquímica
Research Center
Area
Toxicología
Research Group
Ciencias Forenses y Toxicología
PAIDI Areas
Ciencia y Técnicas de la Salud
PhD programs
Biotecnología, Biomedicina y Ciencias de la Salud
Identifiers
UPO investigaORCIDScopus Author IDWeb of Science ResearcherIDDialnet ID

Search Results

Now showing 1 - 4 of 4
  • Publication
    Evaluation of the olive mill wastewater treatment based on advanced oxidation processes (AOPs), flocculation, and filtration
    (Elsevier, 2023) Agabo-García, Cristina; Repetto, Guillermo; Albqmi, Mha; Hodaifa, Gassan
    Different eco-friendly processes are under study to treat olive mill wastewater in the line with European 2024 zero-waste plan. This study is focused on the application of advanced oxidation processes, flocculation, and filtration to determine the best operational condition to obtain high-quality regenerated water in a simple and fast process. In this sense, after photo-Fenton high organic matter removal percentages were obtained: turbidity = 78.3 ± 6.4 %, chemical oxygen demand = 82.9 ± 0.1 %, total organic carbon = 68.9 ± 8.2 %, total phenolic compound = 20.8 ± 9.1 %, and total nitrogen = 64.1 ± 2.1 %. However, the total iron was increased to 792 ± 71 mg/L generating toxicity in the wastewater (100 % mortality in D. magna toxicity test). The subsequent flocculation and filtration steps, refine the water quality. In this sense, different flocculants have been studied to optimize regenerated treated water and the operations time, determining the sedimentation rate in a typical Kynch curve. In quality terms, adjusting the oxidized water to pH = 6 showed the best option to determine lowest values of COD = 131 mg O2/L, TPCs = 0.110 mg/L, and total iron = 0.380 mg/L but with high values for sodium = 1320 mg/L and chloride ions = 473 mg/L. However, with a minimum amount of Nalco 9913 (10 mg/L) and Nalco GR-204 (50 mg/L) highest sedimentation rate was achieved. After three filtration steps, regenerated water for irrigation purposes with the following quality parameters pH = 7.0, electric conductivity = 6.04 mS/cm, turbidity = 0.66 FTU, COD = 451 mg O2/L, TOC = 142 mg/L, TPCs = 0.13 mg/L; sodium ions = 1.50 mg/L, chloride ions = 221 mg/L, total iron = 0.247 mg/L, and no toxicity was obtained.
  • Publication
    (Amino)cyclophosphazenes as Multisite Ligands for the Synthesis of Antitumoral and Antibacterial Silver(I) Complexes
    (ACS Publications, 2020-01-27) Gascón, Elena; Maisanaba, Sara; Otal, Isabel; Valero Blanco, Eva María; Repetto, Guillermo; Jones, Peter G; Jiménez, Josefina
    The reactivity of the multisite (amino)cyclotriphosphazene ligands, [N3P3(NHCy)6] and [N3P3(NHCy)3(NMe2)3], has been explored in order to obtain silver(I) metallophosphazene complexes. Two series of cationic silver(I) metallophosphazenes were obtained and characterized: [N3P3(NHCy)6{AgL}n](TfO)n [n = 2, L = PPh3 (2), PPh2Me (4); n = 3, L = PPh3 (3), PPh2Me (5), TPA (TPA = 1,3,5-triaza-7-phosphaadamantane, 6)] and nongem-trans-[N3P3(NHCy)3(NMe2)3{AgL}n](TfO)n [n = 2, L = PPh3 (7), PPh2Me (9); n = 3, L = PPh3 (8), PPh2Me (10)]. 5, 7, and 9 have also been characterized by single-crystal X-ray diffraction, thereby allowing key bonding information to be obtained. Compounds 2–6, 9, and 10 were screened for in vitro cytotoxic activity against two tumor human cell lines, MCF7 (breast adenocarcinoma) and HepG2 (hepatocellular carcinoma), and for antimicrobial activity against five bacterial species including Gram-positive, Gram-negative, and Mycobacteria strains. Both the IC50 and MIC values revealed excellent biological activity for these metal complexes, compared with their precursors and cisplatin and also AgNO3 and silver sulfadiazine, respectively. Both IC50 and MIC values are among the lowest values found for any silver derivatives against the cell lines and bacterial strains used in this work. The structure–activity relationships were clear. The most cytotoxic and antimicrobial derivatives were those with the triphenylphosphane and [N3P3(NHCy)6] ligands. A significant improvement in the activity was also observed upon a rise in the number of silver atoms linked to the phosphazene ring.
  • Publication
    Gold(I) metallocyclophosphazenes with antibacterial potency and antitumor efficacy. Synergistic antibacterial action of a heterometallic gold and silver-cyclophosphazene
    (Royal Society of Chemistry, 2022-08-22) Gascón, Elena; Otal, Isabel; Maisanaba, Sara; Llana Ruíz-Cabello, María; Valero Blanco, Eva María; Repetto, Guillermo; Jones, Peter G; Oriol, Luis; Jiménez, Josefina
    One of the most important uses of phosphazenes today involves its biomedical applications. They can also be employed as scaffolds for the design and construction of a variety of ligands in order to coordinate them to metallic drugs. The coordination chemistry of the (amino)cyclotriphosphazene ligand, [N3P3(NHCy)6], towards gold(I) complexes has been studied. Neutral complexes, [N3P3(NHCy)6{AuX}n] (X = Cl or C6F5; n = 1 or 2) (1–4), cationic complexes, [N3P3(NHCy)6{Au(PR3)}n](NO3)n (PR3 = PPh3, PPh2Me, TPA; n = 1, 2 or 3) (6–12) [TPA = 1,3,5-triaza-7-phosphaadamantane] and a heterometallic compound [N3P3(NHCy)6{Au(PPh3)}2{Ag(PPh3)}] (NO3)3 (13) have been obtained and characterized by various methods including single-crystal X-ray diffraction for 7, which confirms the coordination of gold atoms to the nitrogens of the phosphazene ring. Compounds 1, 4, 6–13 were screened for in vitro cytotoxic activity against two tumor human cell lines, MCF7 (breast adenocarcinoma) and HepG2 (hepatocellular carcinoma), and for antimicrobial activity against five bacterial species including Gram-positive, Gram-negative, and Mycobacteria. Both the median inhibitory concentration (IC50) and minimum inhibitory concentration (MIC) values are among the lowest found for any gold or silver derivatives against the cell lines and particularly against the Gram-positive (S. aureus) strain and the mycobacteria used in this work. Structure–activity relationships are discussed in order to determine the influence of ancillary ligands and the number and type of metal atoms (silver or gold). Compounds 4 and 8 showed not only maximal potency on human cells but also some tumour selectivity. Remarkably, compound 13, with both gold and silver atoms, showed outstanding activity against both Gram-positive and Gram-negative strains (nanomolar range), thus having a cooperative effect between gold and silver, with MIC values which are similar or lower than those of gentamicine, ciprofloxacin and rifampicine. The broad spectrum antimicrobial efficacy of all these metallophosphazenes and particularly of heterometallic compound 13 could be very useful to obtain materials for surfaces with antimicrobial properties that are increasingly in demand.
  • Publication
    Investigation of mechanisms of toxicity and exclusion by transporters of the preservatives triclosan and propylparaben using batteries of Schizosaccharomyces pombe strains
    (Elsevier, 2019-11-30) Álvarez Herrera, C.; Maisanaba, Sara; Repetto, Guillermo
    Triclosan (TCS) and propylparaben (PPB) are antimicrobials widely used. They present many similarities in their applications and also in their human and environmental health risks. In order to investigate the mechanisms of toxic action and the efflux pumps involved in their detoxication, we used a strategy with batteries of Schizosaccharomyces pombe yeast strains, either defective in cell signalling, in detoxification pumps, or in cell surveillance mechanisms. Yeast were exposed up to 20 h in solid medium or in liquid medium in 96-well plates. The mechanisms of action investigated were spindle defects (mph1), stress (pmk1), DNA interference (rad3) or diverse effects (MDR-sup). The efflux pumps investigated were Bfr1, Pmd1, Mfs1 and Caf5 or the Pap1 transcription factor. Here we show that TCS was 75 times more toxic than PPB in the wild type fission yeast. More oxidative stress and less protection by exclusion pumps were observed for TCS than for PPB. The cytotoxicity produced by TCS decreased from bfr1>mfs1>pmd1 > pap1 and caf5A deficient strains. In contrast, cytotoxic concentrations of PPB caused only a mild stress. The protection provided for PPB by the transporters was more marked than for TCS, decreasing from Pmd1, Caf5, Mfs1 and Bfr1. Furthermore, microtubule and DNA interferences were revealed for PPB, according to the cytotoxicity of mph1 and rad3 defective cells, respectively. As both compounds present complex adverse effects at concentrations close to exposure, and their combination clearly causes a strong potentiation, more exhaustive controls and regulations in their use should be considered.