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1.
J Enzyme Inhib Med Chem ; 38(1): 2171028, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36715272

RESUMO

The synthesis of carborane-1,8-naphthalimide conjugates and evaluation of their DNA-binding ability and anticancer activity were performed. A series of 4-carboranyl-3-nitro-1,8-naphthalimide derivatives, mitonafide and pinafide analogs, were synthesised via amidation and reductive amination reactions, and their calf thymus DNA (ct-DNA)-binding properties were investigated using circular dichroism, UV-vis spectroscopy, and thermal denaturation. Results showed that conjugates 34-37 interacted very strongly with ct-DNA (ΔTm = 10.00-13.00 °C), indicating their ability to intercalate with DNA, but did not inhibit the activity of topoisomerase II. The conjugates inhibited the cell growth of the HepG2 cancer cell line in vitro. The same compounds caused the G2M phase arrest. Cell lines treated with these conjugates showed an increase in reactive oxygen species, glutathione, and Fe2+ levels, lipid peroxidation, and mitochondrial membrane potential relative to controls, indicating the involvement of ferroptosis. Furthermore, these conjugates caused lysosomal membrane permeabilization in HepG2 cells but not in MRC-5 cells.


Assuntos
Antineoplásicos , Ferroptose , Neoplasias , Substâncias Intercalantes , Antineoplásicos/química , Naftalimidas , Linhagem Celular , DNA/química , Lisossomos/metabolismo , Linhagem Celular Tumoral
2.
J Enzyme Inhib Med Chem ; 38(1): 2157825, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36629421

RESUMO

In this research, two novel series of dibenzo[b,f]azepines (14 candidates) were designed and synthesised based on the rigidification principle and following the reported doxorubicin's pharmacophoric features. The anti-proliferative activity was evaluated at the NCI against a panel of 60 cancer cell lines. Further, the promising candidates (5a-g) were evaluated for their ability to inhibit topoisomerase II, where 5e was noticed to be the most active congener. Moreover, its cytotoxicity was evaluated against leukaemia SR cells. Also, 5e arrested the cell cycle at the G1 phase and increased the apoptosis ratio by 37.34%. Furthermore, in vivo studies of 5e showed the inhibition of tumour proliferation and the decrease in its volume. Histopathology and liver enzymes were examined as well. Besides, molecular docking, physicochemical, and pharmacokinetic properties were carried out. Finally, a SAR study was discussed to open the gate for further optimisation of the most promising candidate (5e).HighlightsTwo novel series of dibenzo[b,f]azepines were designed and synthesised based on the rigidification principle in drug design.The anti-proliferative activity was evaluated at the NCI against a panel of 60 cancer cell lines.5e was the most active anti-topo II congener (IC50 = 6.36 ± 0.36 µM).5e was evaluated against leukaemia SR cells and its cytotoxic effect was confirmed (IC50 = 13.05 ± 0.62 µM).In vivo studies of 5e significantly inhibited tumour proliferation by 62.7% and decreased tumour volume to 30.1 mm3 compared to doxorubicin treatment.


Assuntos
Antineoplásicos , Leucemia , Humanos , Inibidores da Topoisomerase II/química , Relação Estrutura-Atividade , Substâncias Intercalantes/farmacologia , Simulação de Acoplamento Molecular , Linhagem Celular Tumoral , Azepinas/farmacologia , Antineoplásicos/química , Doxorrubicina/farmacologia , DNA , Proliferação de Células , Estrutura Molecular , Ensaios de Seleção de Medicamentos Antitumorais , DNA Topoisomerases Tipo II/metabolismo
3.
J Enzyme Inhib Med Chem ; 38(1): 2171029, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36701269

RESUMO

Topoisomerase II (TOP-2) is a promising molecular target for cancer therapy. Numerous antibiotics could interact with biologically relevant macromolecules and provoke antitumor potential. Herein, molecular docking studies were used to investigate the binding interactions of 138 antibiotics against the human topoisomerase II-DNA complex. Followed by the MD simulations for 200 ns and MM-GBSA calculations. On the other hand, the antitumor activities of the most promising candidates were investigated against three cancer cell lines using doxorubicin (DOX) as a reference drug. Notably, spiramycin (SP) and clarithromycin (CL) showed promising anticancer potentials on the MCF-7 cell line. Moreover, azithromycin (AZ) and CL exhibited good anticancer potentials against the HCT-116 cell line. Finally, the TOP-2 enzyme inhibition assay was carried out to confirm the proposed rationale. Briefly, potent TOP-2 inhibitory potentials were recorded for erythromycin (ER) and roxithromycin (RO). Additionally, a SAR study opened eyes to promising anticancer pharmacophores encountered by these antibiotics.HighlightsMolecular docking studies of 139 antibiotics against the topoisomerase II-DNA complex.SP, RO, AZ, CL, and ER were the most promising and commercially available candidates.Molecular dynamics simulations for 200 ns for the most promising five complexes.MM-GBSA calculations for the frontier five complexes.SP and CL showed promising anticancer potentials on the MCF-7 cell line, besides, AZ and CL exhibited good anticancer potentials against the HCT-116 cell line.Potent TOP-2 inhibitory potentials were recorded for ER and RO.


Assuntos
Antineoplásicos , Inibidores da Topoisomerase II , Humanos , Inibidores da Topoisomerase II/farmacologia , Inibidores da Topoisomerase II/química , Simulação de Acoplamento Molecular , Estrutura Molecular , Antineoplásicos/farmacologia , Antineoplásicos/química , Substâncias Intercalantes/farmacologia , Antibacterianos/farmacologia , Relação Estrutura-Atividade , Simulação de Dinâmica Molecular , Linhagem Celular Tumoral , DNA , DNA Topoisomerases Tipo II/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais
4.
Sci Rep ; 13(1): 1456, 2023 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-36702871

RESUMO

Poly(ADP-ribose) polymerase (PARP) are critical DNA repair enzymes that are activated as part of the DNA damage response (DDR). Although inhibitors of PARP (PARPi) have emerged as small molecule drugs and have shown promising therapeutic effects, PARPi used as single agents are clinically limited to patients with mutations in germline breast cancer susceptibility gene (BRCA). Thus, novel PARPi combination strategies may expand their usage and combat drug resistance. In recent years, ruthenium polypyridyl complexes (RPCs) have emerged as promising anti-cancer candidates due to their attractive DNA binding properties and distinct mechanisms of action. Previously, we reported the rational combination of the RPC DNA replication inhibitor [Ru(dppz)2(PIP)]2+ (dppz = dipyrido[3,2-a:2',3'-c]phenazine, PIP = 2-(phenyl)-imidazo[4,5-f][1,10]phenanthroline), "Ru-PIP", with the PARPi Olaparib in breast cancer cells. Here, we expand upon this work and examine the combination of Ru-PIP with Olaparib for synergy in lung cancer cells, including in 3D lung cancer spheroids, to further elucidate mechanisms of synergy and additionally assess toxicity in a zebrafish embryo model. Compared to single agents alone, Ru-PIP and Olaparib synergy was observed in both A549 and H1975 lung cancer cell lines with mild impact on normal lung fibroblast MRC5 cells. Employing the A549 cell line, synergy was confirmed by loss in clonogenic potential and reduced migration properties. Mechanistic studies indicated that synergy is accompanied by increased double-strand break (DSB) DNA damage and reactive oxygen species (ROS) levels which subsequently lead to cell death via apoptosis. Moreover, the identified combination was successfully able to inhibit the growth of A549 lung cancer spheroids and acute zebrafish embryos toxicity studies revealed that this combination showed reduced toxicity compared to single-agent Ru-PIP.


Assuntos
Antineoplásicos , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Rutênio , Animais , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Rutênio/farmacologia , Rutênio/química , Substâncias Intercalantes , Peixe-Zebra , Neoplasias Pulmonares/tratamento farmacológico , Antineoplásicos/farmacologia , Ftalazinas/farmacologia , DNA , Linhagem Celular Tumoral
5.
Molecules ; 27(23)2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36500248

RESUMO

Proflavine is an acridine derivative which was discovered as one of the earliest antibacterial agents, and it has been proven to have potential application to fields such as chemotherapy, photobiology and solar-energy conversion. In particular, it is well known that proflavine can bind to DNA with different modes, and this may open addition photochemical-reaction channels in DNA. Herein, the excited-state dynamics of proflavine after intercalation into DNA duplex is studied using femtosecond time-resolved spectroscopy, and compared with that in solution. It is demonstrated that both fluorescence and the triplet excited-state generation of proflavine were quenched after intercalation into DNA, due to ultrafast non-radiative channels. A static-quenching mechanism was identified for the proflavine-DNA complex, in line with the spectroscopy data, and the excited-state deactivation mechanism was proposed.


Assuntos
Substâncias Intercalantes , Proflavina , Proflavina/química , DNA/química , Acridinas
6.
Analyst ; 147(22): 5231-5238, 2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36278807

RESUMO

Polarity and viscosity, as important microenvironment parameters, play an essential role in cell metabolism. Therefore, 9-acridine carboxaldehyde reacted with cyano compounds to obtain polarity-sensitive probes 1a-b and viscosity-sensitive probes 1c-d. Among them, with the increase in solvent polarity, the maximum emission wavelength of acridine-dicyanoisophorone-based probe 1a red-shifted from 553 nm to 594 nm, the fluorescence quantum yield increased from 0.5% to 35.6%, and the fluorescence intensity enhanced 38 fold. The acridine-cyanofuranone based probe 1b also has a polarity response similar to 1a. Nevertheless, when the solution viscosity increased from 0.89 cP (100% water) to 856 cP (1% water), the fluorescence intensity of the acridine-tricyanodihydrofuran based probe 1c at 430 nm enhanced 5.6 times. The acridine-cyanobenzothiazole based probe 1d also had a viscosity response similar to 1c. In addition, probes 1a-b were used for further HeLa cell imaging experiments due to their good photostability and the results suggested that probe 1a could locate lipid droplets and probes 1b-c could stain lysosomes. Moreover, probes 1a-b could dynamically monitor the changes in intracellular polarity.


Assuntos
Polaridade Celular , Corantes Fluorescentes , Humanos , Espectrometria de Fluorescência , Células HeLa , Substâncias Intercalantes , Água , Viscosidade , Acridinas
7.
Antiviral Res ; 207: 105416, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36113629

RESUMO

Cellular responses to stress generally lead to the activation of the endoplasmic reticulum-associated protein degradation (ERAD) pathway. Several lines of study support that ERAD may be playing a proviral role during flaviviral infection. A key host factor in ERAD is the valosin-containing protein (VCP), an ATPase which ushers ubiquitin-tagged proteins to degradation by the proteasome. VCP exhibits different proviral activities, such as engaging in the biogenesis of viral replication organelles and facilitating flavivirus genome uncoating after the viral particle entry. To investigate the possible antiviral value of drugs targeting VCP, we tested two inhibitors: eeyarestatin I (EEY) and xanthohumol (XAN). Both compounds were highly effective in suppressing Zika virus (ZIKV) and Usutu virus (USUV) replication during infection in cell culture. Further analysis revealed an unexpected virucidal activity for EEY, but not for XAN. Preincubation of ZIKV or USUV with EEY before inoculation to cells resulted in significant decreases in infectivity in a dose- and time-dependent manner. Viral genomes in samples previously treated with EEY were more sensitive to propidium monoazide, an intercalating agent, with 10- to 100-fold decreases observed in viral RNA levels, supporting that EEY affects viral particle integrity. Altogether, these results support that EEY is a strong virucide against two unrelated flaviviruses, encouraging further studies to investigate its potential use as a broad-acting drug or the development of improved derivatives in the treatment of flaviviral infection.


Assuntos
Infecções por Flavivirus , Flavivirus , Infecção por Zika virus , Zika virus , Adenosina Trifosfatases/metabolismo , Adenosina Trifosfatases/farmacologia , Adenosina Trifosfatases/uso terapêutico , Antivirais/farmacologia , Antivirais/uso terapêutico , Flavivirus/genética , Humanos , Hidrazonas , Hidroxiureia/análogos & derivados , Substâncias Intercalantes/farmacologia , Substâncias Intercalantes/uso terapêutico , Complexo de Endopeptidases do Proteassoma/metabolismo , RNA Viral/genética , Ubiquitinas/metabolismo , Proteína com Valosina/metabolismo , Replicação Viral
8.
Org Biomol Chem ; 20(45): 8873-8884, 2022 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-36102841

RESUMO

The low binding affinity of unmodified triplex-forming oligonucleotides (TFO) is the main drawback to their promising utilization in gene therapy. In the present study, we have synthesized DNA intercalator 5-(pyren-1-ylethynyl)indole Y, known as twisted intercalating nucleic acid (TINA), by a Cu-mediated Sonogashira palladium-catalyzed coupling reaction of 1-ethynylpyrene with 5-iodoindole at a high temperature under anaerobic conditions. Coupling with indole C-5 was far more preferable in obtaining stable TINA-indole than enamine site C-3, as neither hydration of the triple bond to ketones nor competitive Glaser-type homocoupling of acetylenes was observed. The insertion of the new TINA monomer Y as a bulge in the middle or at the 5'-end of the oligodeoxynucleotide sequence via a flexible butane-1,2-diol linker showed extraordinary binding potential, resulting in excellent thermal stabilization of Hoogsteen-type triplex- and duplex-deoxyribonucleic acid (DNA) structures which was detected by thermal denaturation studies and supported by circular dichroism (CD). Molecular dynamics AMBER* revealed the lowest energy conformation in which a pyrenyl residue of the TINA monomer Y stacks in the dsDNA part, while an indolyl unit intercalates between the nucleobases of the TFO pattern. Overall the torsionally rigid conjugated TINA system with a decent twisting of 15.1° around acetylene is confirmed here as a requirement for the best fit inside the intercalation site of the triplex, resulting in high TFO-dsDNA affinity.


Assuntos
Substâncias Intercalantes , Ácidos Nucleicos , Temperatura , Substâncias Intercalantes/química , Oligonucleotídeos/química , Pirenos/química , DNA/química , Ácidos Nucleicos/química , Indóis , Conformação de Ácido Nucleico , Desnaturação de Ácido Nucleico
9.
Inorg Chem ; 61(38): 14947-14961, 2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36094851

RESUMO

The synthesis and photophysical characterization of two osmium(II) polypyridyl complexes, [Os(TAP)2dppz]2+ (1) and [Os(TAP)2dppp2]2+ (2) containing dppz (dipyrido[3,2-a:2',3'-c]phenazine) and dppp2 (pyrido[2',3':5,6]pyrazino[2,3-f][1,10]phenanthroline) intercalating ligands and TAP (1,4,5,8-tetraazaphenanthrene) ancillary ligands, are reported. The complexes exhibit complex electrochemistry with five distinct reductive redox couples, the first of which is assigned to a TAP-based process. The complexes emit in the near-IR (1 at 761 nm and 2 at 740 nm) with lifetimes of >35 ns with a low quantum yield of luminescence in aqueous solution (∼0.25%). The Δ and Λ enantiomers of 1 and 2 are found to bind to natural DNA and with AT and GC oligodeoxynucleotides with high affinities. In the presence of natural DNA, the visible absorption spectra are found to display significant hypochromic shifts, which is strongly evident for the ligand-centered π-π* dppp2 transition at 355 nm, which undergoes 46% hypochromism. The emission of both complexes increases upon DNA binding, which is observed to be sensitive to the Δ or Λ enantiomer and the DNA composition. A striking result is the sensitivity of Λ-2 to the presence of AT DNA, where a 6-fold enhancement of luminescence is observed and reflects the nature of the binding for the enantiomer and the protection from solution. Thermal denaturation studies show that both complexes are found to stabilize natural DNA. Finally, cellular studies show that the complexes are internalized by cultured mammalian cells and localize in the nucleus.


Assuntos
Substâncias Intercalantes , Rutênio , Animais , DNA/química , Substâncias Intercalantes/química , Ligantes , Mamíferos/metabolismo , Oligodesoxirribonucleotídeos , Osmio , Fenantrolinas/química , Fenazinas/química , Rutênio/química
10.
Nucleic Acids Res ; 50(18): 10212-10229, 2022 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-36156152

RESUMO

The short oligodeoxynucleotide (ODN) probes are suitable for good discrimination of point mutations. However, the probes suffer from low melting temperatures. In this work, the strategy of using acridine-4-carboxamide intercalators to improve thermal stabilisation is investigated. The study of large series of acridines revealed that optimal stabilisation is achieved upon decoration of acridine by secondary carboxamide carrying sterically not demanding basic function bound through a two-carbon linker. Two highly active intercalators were attached to short probes (13 or 18 bases; designed as a part of HFE gene) by click chemistry into positions 7 and/or 13 and proved to increase the melting temperate (Tm) of the duplex by almost 8°C for the best combination. The acridines interact with both single- and double-stranded DNAs with substantially preferred interaction for the latter. The study of interaction suggested higher affinity of the acridines toward the GC- than AT-rich sequences. Good discrimination of two point mutations was shown in practical application with HFE gene (wild type, H63D C > G and S65C A > C mutations). Acridine itself can also serve as a fluorophore and also allows discrimination of the fully matched sequences from those with point mutations in probes labelled only with acridine.


Assuntos
Acridinas , Substâncias Intercalantes , Carbono , DNA/genética , DNA/metabolismo , Oligodesoxirribonucleotídeos
11.
Environ Res ; 214(Pt 3): 113960, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35921909

RESUMO

The need for abundant photocatalyst in wastewater treatment is currently a must. A simple intercalation process was utilized to exfoliate Kaolinite clay mineral structure Al2Si2O5(OH)4 into two-dimensional nanostructured separated layers operated in visible light range. The intercalating agents were hydrazine hydrate and urea. Detailed characterization confirmed the nanolayered structures of kaolinite hexagonal nanosheets (NK). In addition, Bandgap energy was reduced based on intercalating agents from 3.45 to 2.48 eV as revealed by light absorption spectra. The quenching of PL spectra for the nK has also been ascribed to the suppression of charge carrier recombination. The exfoliated nK was utilized to photodegrade Rhodamine B dye (RhB) and P-nitrophenol (PNP) as industrial pollutants in wastewater. The results showed 92.3% and 99.7% photodegradation of RhB and PNP within 180 min of visible-light irradiation utilizing the exfoliated NK by urea. We denote the boosted photocatalytic performance of this NK to the uncovered, low bandgap metal oxide inclusions on the exterior of NK besides the nitrogen doping due to exfoliation with urea. This simple exfoliation has modified abundant and stable clay nanolayers that are a promising alternative for the eminent nanostructured oxide photocatalysts to overcome the organic pollutants in wastewater at a high scale.


Assuntos
Poluentes Ambientais , Caulim , Catálise , Argila , Substâncias Intercalantes , Luz , Óxidos , Fotólise , Ureia , /química
12.
ChemMedChem ; 17(20): e202200444, 2022 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-36041073

RESUMO

Herein we illustrate the formation and characterization of new paramagnetic ruthenium compounds, trans-P-[RuCl(PPh3 )2 (pmt)]Cl (1) (Hpmt=1-((pyridin-2-yl)methylene)thiosemicarbazide), trans-P-[RuCl(PPh3 )2 (tmc)]Cl (2) (Htmc=1-((thiophen-2-yl)methylene)thiosemicarbazide) and a diamagnetic ruthenium complex, cis-Cl, trans-P-[RuCl2 (PPh3 )2 (btm)] (3) (btm=2-((5-hydroxypentylimino)methyl)benzothiazole). Agarose gel electrophoresis experiments of the metal compounds illustrated dose-dependent binding to gDNA by 1-3, while methylene blue competition assays suggested that 1 and 2 are also DNA intercalators. Assessment of the effects of the compounds on topoisomerase function indicated that 1-3 are capable of inhibiting topoisomerase I activity in terms of the ability to nick supercoiled plasmid DNA. The cytotoxic activities of the metal complexes were determined against a range of cancer cell lines versus a non-tumorigenic control cell line, and the complexes were, in general, more cytotoxic towards the cancer cells, displaying IC50 values in the low micromolar range. Time-dependent stability studies showed that in the presence of strong nucleophilic species (such as DMSO), the chloride co-ligands of 1-3 are rapidly substituted by the former as proven by the suppression of the substitution reactions in the presence of an excess amount of chloride ions. The metal complexes are significantly stable in both DCM and an aqueous phosphate buffer containing 2 % DMSO.


Assuntos
Antineoplásicos , Complexos de Coordenação , Compostos Organometálicos , Rutênio , Tiossemicarbazonas , Compostos de Rutênio/química , Compostos de Rutênio/metabolismo , Rutênio/farmacologia , Rutênio/química , Tiossemicarbazonas/farmacologia , Complexos de Coordenação/toxicidade , Complexos de Coordenação/química , Bases de Schiff/farmacologia , Dimetil Sulfóxido , Azul de Metileno , Substâncias Intercalantes , Cloretos , DNA Topoisomerases Tipo I/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/química , DNA/química , Benzotiazóis/farmacologia , Fosfatos , Compostos Organometálicos/química
13.
J Med Chem ; 65(17): 11415-11432, 2022 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-36018000

RESUMO

Acriflavine (ACF) has been known for years as an antibacterial drug. The identification of key oncogenic mechanisms has brought, in recent years, a significant increase in studies on ACF as a multipurpose drug that would improve the prognosis for cancer patients. ACF interferes with the expression of the hypoxia inducible factor, thus acting on metastatic niches of tumors and significantly enhancing the effects of other anticancer therapies. It has been recognized as the most potent HIF-1 inhibitor out of the 336 drugs approved by the FDA. This work presents up-to-date knowledge about the mechanisms of action of ACF and its related prodrug systems in the context of anticancer and SARS-CoV-2 inhibitory properties. It explains the multitask nature of this drug and suggests mechanisms of ACF's action on the coronavirus. Other recent reports on ACF-based systems as potential antibacterial and antiviral drugs are also described.


Assuntos
Neoplasias , Acridinas/farmacologia , Acridinas/uso terapêutico , Acriflavina/farmacologia , Acriflavina/uso terapêutico , Antibacterianos , Humanos , Substâncias Intercalantes , SARS-CoV-2
14.
Chem Biol Drug Des ; 100(4): 580-598, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35822451

RESUMO

Cancer is one of the most prevailing disease conditions, which occurs due to uncontrolled cell division either due to natural mutation to the genes or due to changes induced by physical, chemical, or biological carcinogens. According to WHO, it is the second leading cause of death worldwide and has reported 10 million deaths in 2020. Hence, there arises the need for better chemotherapies and DNA intercalators are one such emerging therapy for cancer. DNA intercalating agents reversibly intercalate with the double-helical structure of DNA by interacting with adjacent base pairs and disrupting the structure of DNA and thereby causing cell death. Here, we discuss the different classes of organo-intercalators used in cancer therapy describing their anticancer and intercalation ability by different methods along with their structure-activity relationship and mechanism of action.


Assuntos
Antineoplásicos , Neoplasias , Antineoplásicos/química , Carcinógenos , DNA/química , Humanos , Substâncias Intercalantes/química , Neoplasias/tratamento farmacológico
15.
PLos ONE ; 17(6): 1-14, 14 jun. 2022. tab, graf
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IALPROD, Sec. Est. Saúde SP | ID: biblio-1392280

RESUMO

Meningitis caused by Streptococcus pneumoniae is still a disease of great impact on Public health, which requires immediate diagnosis and treatment. However, the culture of clinical specimens is often negative and antibiotic susceptibility testing (AST) must be performed with isolated strains. Multiplex real-time polymerase chain reaction (qPCR) has high sensitivity and specificity, produces faster results to identify the pathogen, and it can also be an important tool to identify resistance antibiotic genes earlier than AST, especially in the absence of an isolated strain. This study developed a multiplex qPCR assay, using SYBR Green as a nonspecific dye, to detect antibiotic resistance genes to predict pneumococcal susceptibility/resistance in cerebrospinal fluid (CSF) samples from meningitis patients. From 2017 to 2020, CSF samples were cultured and analyzed by qPCR to detect the main three bacteria causing meningitis. Isolated and reference strains were applied in SYBR Green qPCR multiplex to detect pbp2b, ermB, and mef genes, and the results were compared with the AST. Pneumococcal-positive CSF samples (lytA-positive gene) without isolated strains were also tested to evaluate the antimicrobial susceptibility profile in the region from 2014 to 2020. From the received 873 CSF samples; 263 were cultivated, 149 were lytA-positive in the qPCR, and 25 produced viable isolated pneumococci strains, which were evaluated by AST. Melting temperature for each gene and the acceptance criteria were determined (pbp2b: 78.24­79.86; ermB: 80.88­82.56; mef: 74.85­76.34 ºC). A total of 48/51 strains presented a genetic profile in agreement with the AST results. Resistant strains to erythromycin and clindamycin were ermB-positive, and two were also mef-positive, indicating both resistance mechanisms were present. In the retrospective study of the genetic profile of resistance, 82 lytA-positive CSF samples plus 4 strains were applied in the SYBR Green qPCR multiplex: 51% of samples presented the wild genotype (pbp2b positive and ermB/mef negative); 15% were negative for all the three evaluated, indicating pneumococci resistant to penicillin; and 17% represented the multidrug-resistant pneumococci (pbp2b negative and ermB positive or pbp2b negative and ermB and mef positive). Therefore, SYBR Green qPCR multiplex proved to be a reliable tool to identify resistance genes in S.pneumoniae and would be less expensive than multiplex qPCR using specific probes. This could be easily introduced into the routine of diagnostic laboratories and provide a strong presumption of pneumococcal resistance, especially in the absence of isolated strains. (AU)


Assuntos
Streptococcus pneumoniae , Resistência Microbiana a Medicamentos , Líquido Cefalorraquidiano , Corantes , Reação em Cadeia da Polimerase Multiplex , Substâncias Intercalantes , Meningite
16.
Molecules ; 27(9)2022 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-35566236

RESUMO

A series of novel acridine N-acylhydrazone derivatives have been synthesized as potential topoisomerase I/II inhibitors, and their binding (calf thymus DNA-ctDNA and human serum albumin-HSA) and biological activities as potential anticancer agents on proliferation of A549 and CCD-18Co have been evaluated. The acridine-DNA complex 3b (-F) displayed the highest Kb value (Kb = 3.18 × 103 M-1). The HSA-derivatives interactions were studied by fluorescence quenching spectra. This method was used for the calculation of characteristic binding parameters. In the presence of warfarin, the binding constant values were found to decrease (KSV = 2.26 M-1, Kb = 2.54 M-1), suggesting that derivative 3a could bind to HSA at Sudlow site I. The effect of tested derivatives on metabolic activity of A549 cells evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide or MTT assay decreased as follows 3b(-F) > 3a(-H) > 3c(-Cl) > 3d(-Br). The derivatives 3c and 3d in vitro act as potential dual inhibitors of hTopo I and II with a partial effect on the metabolic activity of cancer cells A594. The acridine-benzohydrazides 3a and 3c reduced the clonogenic ability of A549 cells by 72% or 74%, respectively. The general results of the study suggest that the novel compounds show potential for future development as anticancer agents.


Assuntos
Antineoplásicos , Acridinas/química , Antineoplásicos/química , Sítios de Ligação , Humanos , Substâncias Intercalantes , Albumina Sérica Humana/química , Inibidores da Topoisomerase II/farmacologia
17.
Sci Rep ; 12(1): 7423, 2022 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-35523933

RESUMO

The microplastic that pollutes the ocean is a serious problem around the world. The bioplastic consisting of biopolymers which is degraded in nature, is one of the strategies to solve this problem. Although the bioplastics consisting of protein, polysaccharide, polylactic acid, etc., have been reported, which consist of DNA, one of the most important materials in the genetic process, have not been reported to the best of our knowledge. In addition, a large amount of DNA-containing materials, such as salmon milts, is discarded as industrial waste around the world. Therefore, we demonstrated the preparation of a bioplastic consisting of salmon milt DNA. The DNA plastic was prepared by the immersion of a DNA pellet in a formaldehyde (HCHO) solution and heating. As a result, the water-stable DNA plastics were obtained at the HCHO concentration of 20% or more. Particularly, the DNA plastic with a 25% HCHO treatment showed water-insoluble, thermally stable, and highly mechanical properties. These are due to the formation of a three-dimensional network via the crosslinking reaction between the DNA chains. In addition, since DNA in plastic possesses the double-stranded structure, these plastics effectively accumulated the DNA intercalator, such as ethidium bromide. Furthermore, the DNA plastics indicated a biodegradable property in a nuclease-containing aqueous solution and the biodegradable stability was able to be controlled by the HCHO concentration. Therefore, salmon milt DNA has shown the potential to be a biodegradable plastic.


Assuntos
Plásticos Biodegradáveis , Plásticos , Animais , DNA/química , Substâncias Intercalantes , Salmão , Água
18.
Biosensors (Basel) ; 12(5)2022 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-35624630

RESUMO

The detection of small molecules interacting with DNA is important for the assessment of potential hazards related to the application of rather toxic antitumor drugs, and for distinguishing the factors related to thermal and oxidative DNA damage. In this work, a novel electrochemical DNA sensor has been proposed for the determination of antitumor drugs. For DNA sensor assembling, a glassy carbon electrode was modified with carbon black dispersed in DMF. After that, pillar [5]arene was adsorbed and Methylene blue and Neutral red were consecutively electropolymerized onto the carbon black layer. To increase sensitivity of intercalator detection, DNA was first mixed with water-soluble thiacalixarene bearing quaternary ammonium groups in the substituents at the lower rim. The deposition of the mixture on the electropolymerized dyes made it possible to detect doxorubicin as model intercalator by suppression of the redox activity of the polymerization products. The DNA sensor made it possible to determine 0.5 pM-1.0 nM doxorubicin (limit of detection 0.13 pM) with 20 min of incubation. The DNA sensor was successfully tested on spiked samples of human plasma and doxorubicin medication.


Assuntos
Azul de Metileno , Fuligem , DNA/química , Doxorrubicina , Humanos , Substâncias Intercalantes , Vermelho Neutro , Poli A
19.
J Enzyme Inhib Med Chem ; 37(1): 1556-1567, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35635148

RESUMO

Sixteen [1, 2, 4]triazolo[4,3-a]quinoxalines as DNA intercalators-Topo II inhibitors have been prepared and their anticancer actions evaluated towards three cancer cell lines. The new compounds affected on high percentage of MCF-7. Derivatives 7e, 7c and 7b exhibited the highest anticancer activities. Their activities were higher than that of doxorubicin. Molecular docking studies showed that the HBA present in the chromophore, the substituted distal phenyl moiety and the extended linkers enable our derivatives to act as DNA binders. Also, the pyrazoline moiety formed six H-bonds and improved affinities with DNA active site. Finally, 7e, 7c and 7b exhibited the highest DNA affinities and act as traditional intercalators of DNA. The most active derivatives 7e, 7c, 7b, 7g and 6e were subjected to evaluate their Topo II inhibition and DNA binding actions. Derivative 7e exhibited the highest binding affinity. It intercalates DNA at IC50 = 29.06 µM. Moreover, compound 7e potently intercalates DNA at an IC50 value of 31.24 µM. Finally, compound 7e demonstrated the most potent Topo II inhibitor at a value of 0.890 µM. Compound 7c exhibited an equipotent IC50 value (0.940 µM) to that of doxorubicin. Furthermore, derivatives 7b, 7c, 7e and 7g displayed a high ADMET profile.


Assuntos
Substâncias Intercalantes , Inibidores da Topoisomerase II , DNA , DNA Topoisomerases Tipo II/metabolismo , Relação Dose-Resposta a Droga , Doxorrubicina/farmacologia , Substâncias Intercalantes/farmacologia , Simulação de Acoplamento Molecular , Estrutura Molecular , Relação Estrutura-Atividade , Inibidores da Topoisomerase II/química , Inibidores da Topoisomerase II/farmacologia
20.
Anal Chem ; 94(22): 7747-7751, 2022 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-35609246

RESUMO

We developed a new electrochemical impedimetric method for the real-time detection of polymerase chain reactions (PCR) based on our recent discovery that the DNA intercalator, [Ru(bpy)2DPPZ]2+, anomalously enhances charge transfer between redox mediators, K4[Fe(CN)6]/K3[Fe(CN)6], and a carbon electrode. Three mM [Fe(CN)6]3-/4- and 5 µM [Ru(bpy)2DPPZ]2+ were added to the PCR solution, and electrochemical impedance spectroscopy (EIS) measurements were performed at each elongation heat cycle. The charge transfer resistance (Rct) was initially low due to the presence of [Ru(bpy)2DPPZ]2+ in the solution. As PCR progressed, amplicon dsDNA was produced exponentially, and intercalated [Ru(bpy)2DPPZ]2+ ions, which could be detected as a steep Rct, increased at specific heat cycles depending on the amount of template DNA. The Rct increase per heat cycle, ΔRct, showed a peak at the same heat cycle as optical detection, proving that PCR can be accurately monitored in real time by impedance measurement. This simple method will enable a cost-effective and portable PCR device.


Assuntos
Espectroscopia Dielétrica , Substâncias Intercalantes , DNA/química , Espectroscopia Dielétrica/métodos , Técnicas Eletroquímicas , Substâncias Intercalantes/química , Reação em Cadeia da Polimerase em Tempo Real
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