RESUMEN
Aroylhydrazone iron chelators such as salicylaldehyde isonicotinoyl hydrazone (SIH) protect various cells against oxidative injury and display antineoplastic activities. Previous studies have shown that a nitro-substituted hydrazone, namely, NHAPI, displayed markedly improved plasma stability, selective antitumor activity, and moderate antioxidant properties. In this study, we prepared four series of novel NHAPI derivatives and explored their iron chelation activities, anti- or pro-oxidant effects, protection against model oxidative injury in the H9c2 cell line derived from rat embryonic cardiac myoblasts, cytotoxicities to the corresponding noncancerous H9c2 cells, and antiproliferative activities against the MCF-7 human breast adenocarcinoma and HL-60 human promyelocytic leukemia cell lines. Nitro substitution had both negative and positive effects on the examined properties, and we identified new structure-activity relationships. Naphthyl and biphenyl derivatives showed selective antiproliferative action, particularly in the breast adenocarcinoma MCF-7 cell line, where they exceeded the selectivity of the parent compound NHAPI. Of particular interest is a compound prepared from 2-hydroxy-5-methyl-3-nitroacetophenone and biphenyl-4-carbohydrazide, which protected cardiomyoblasts against oxidative injury at 1.8 ± 1.2 µM with 24-fold higher selectivity than SIH. These compounds will serve as leads for further structural optimization and mechanistic studies.
Asunto(s)
Antineoplásicos/farmacología , Antioxidantes/farmacología , Hidrazonas/farmacología , Quelantes del Hierro/farmacología , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Antineoplásicos/toxicidad , Antioxidantes/síntesis química , Antioxidantes/química , Antioxidantes/toxicidad , Línea Celular Tumoral , Estabilidad de Medicamentos , Humanos , Hidrazonas/síntesis química , Hidrazonas/química , Hidrazonas/toxicidad , Quelantes del Hierro/síntesis química , Quelantes del Hierro/química , Quelantes del Hierro/toxicidad , Radioisótopos de Hierro , Estructura Molecular , Estrés Oxidativo/efectos de los fármacos , Ratas , Relación Estructura-ActividadRESUMEN
Aroylhydrazones such as salicylaldehyde isonicotinoyl hydrazone (SIH) are tridentate iron chelators that may possess antioxidant and/or antineoplastic activities. Their main drawback, their low stability in plasma, has recently been partially overcome by exchanging the aldimine hydrogen for an unbranched alkyl group. In this study, ten analogs of methyl- and ethyl-substituted SIH derivatives with modified hydrazide scaffolds were synthesized to further explore their structure-activity relationships. Their iron-chelation efficiencies, anti- or pro-oxidant potentials, abilities to induce protection against model oxidative injury on the H9c2 cell line derived from rat embryonic cardiac tissue, cytotoxicities on the same H9c2 cells and antiproliferative activities on MCF-7 human breast adenocarcinoma and HL-60 human promyelotic leukemia cell lines were evaluated. Compounds derived from lipophilic naphthyl and biphenyl hydrazides displayed highly selective antiproliferative activities against both MCF-7 and HL-60 cell lines, and they showed markedly improved stabilities in plasma compared to SIH. Of particular interest is a hydrazone prepared from 2-hydroxypropiophenone and pyridazin-4-carbohydrazide that showed a considerable antiproliferative effect and protected cardiomyoblasts against oxidative stress with a five-fold higher selectivity compared to the parent compound SIH. Thus, this work highlighted new structure-activity relationships among antiproliferative and antioxidant aroylhydrazones and identified new lead compounds for further development.
Asunto(s)
Antineoplásicos/química , Antioxidantes/química , Hidrazonas/farmacología , Quelantes del Hierro/química , Animales , Antineoplásicos/farmacología , Antioxidantes/farmacología , Línea Celular Tumoral , Estabilidad de Medicamentos , Humanos , Hidrazinas , Hidrazonas/química , Interacciones Hidrofóbicas e Hidrofílicas , Quelantes del Hierro/farmacología , Ratas , Relación Estructura-ActividadRESUMEN
Salicylaldehyde isonicotinoyl hydrazone (SIH) is a lipophilic, tridentate iron chelator with marked anti-oxidant and modest cytotoxic activity against neoplastic cells. However, it has poor stability in an aqueous environment due to the rapid hydrolysis of its hydrazone bond. In this study, we synthesized a series of new SIH analogs (based on previously described aromatic ketones with improved hydrolytic stability). Their structure-activity relationships were assessed with respect to their stability in plasma, iron chelation efficacy, redox effects and cytotoxic activity against MCF-7 breast adenocarcinoma cells. Furthermore, studies assessed the cytotoxicity of these chelators and their ability to afford protection against hydrogen peroxide-induced oxidative injury in H9c2 cardiomyoblasts. The ligands with a reduced hydrazone bond, or the presence of bulky alkyl substituents near the hydrazone bond, showed severely limited biological activity. The introduction of a bromine substituent increased ligand-induced cytotoxicity to both cancer cells and H9c2 cardiomyoblasts. A similar effect was observed when the phenolic ring was exchanged with pyridine (i.e., changing the ligating site from O, N, O to N, N, O), which led to pro-oxidative effects. In contrast, compounds with long, flexible alkyl chains adjacent to the hydrazone bond exhibited specific cytotoxic effects against MCF-7 breast adenocarcinoma cells and low toxicity against H9c2 cardiomyoblasts. Hence, this study highlights important structure-activity relationships and provides insight into the further development of aroylhydrazone iron chelators with more potent and selective anti-neoplastic effects.
Asunto(s)
Aldehídos/química , Aldehídos/farmacología , Antineoplásicos/toxicidad , Antioxidantes/farmacología , Hidrazonas/química , Hidrazonas/farmacología , Quelantes del Hierro/farmacología , Aldehídos/toxicidad , Antineoplásicos/química , Antioxidantes/química , Línea Celular , Humanos , Hidrazonas/toxicidad , Peróxido de Hidrógeno/toxicidad , Quelantes del Hierro/química , Células MCF-7 , Mioblastos/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Relación Estructura-ActividadRESUMEN
Wheat B-starch was hydrolysed by α-amylase "Liquozyme supra" from Bacillus licheniformis at 90 °C and pH 7. After 2 h, the dextrose equivalent was 18; according to size exclusion chromatography, however, the hydrolysate contained not only dominant malto-oligosaccharides with the degree of polymerisation (DP)<10 but also more than 20% of components with DP higher than 40. The product was acetylated to a high degree as verified by FTIR and (1)H NMR (degree of substitution DS=3.1); nevertheless, detailed analysis of the MALDI-TOF mass spectra of the product showed that most of the malto-oligosaccharides molecules contained one or two residual hydroxyls. Size exclusion chromatography confirmed that the acetylated maltodextrin still contained a significant part with DP>40. This non-uniformity of acetylated maltodextrin, both with respect to DP and to DS, must be taken into account in the development of acetylated-maltodextrin applications such as use as plasticisers or compatibilisers in biodegradable composites.
Asunto(s)
Polisacáridos/química , Almidón/química , Triticum/química , Acetilación , Hidrólisis , Cinética , Peso MolecularRESUMEN
Salicylaldehyde isonicotinoyl hydrazone (SIH) is a lipophilic, orally-active tridentate iron chelator providing both effective protection against various types of oxidative stress-induced cellular injury and anticancer action. However, the major limitation of SIH is represented by its labile hydrazone bond that makes it prone to plasma hydrolysis. Recently, nine new SIH analogues derived from aromatic ketones with improved hydrolytic stability were developed. Here we analyzed their antiproliferative potential in MCF-7 breast adenocarcinoma and HL-60 promyelocytic leukemia cell lines. Seven of the tested substances showed greater selectivity than the parent agent SIH towards the latter cancer cell lines compared to non-cancerous H9c2 cardiomyoblast-derived cells. The tested chelators induced a dose-dependent dissipation of the inner mitochondrial membrane potential, an induction of apoptosis as evidenced by Annexin V positivity or significant increases of activities of caspases 3, 7, 8 and 9 and cell cycle arrest. With the exception of nitro group-bearing NHAPI, the studies of iron complexes of the chelators confirmed the crucial role of iron in the mechanism of their antiproliferative action. Finally, all the assayed chelators inhibited the oxidation of ascorbate by iron ions indicating lack of redox activity of the chelator-iron complexes. In conclusion, this study identified several important design criteria for improvement of the antiproliferative selectivity of the aroylhydrazone iron chelators. Several of the novel compounds--in particular the ethylketone-derived HPPI, NHAPI and acetyl-substituted A2,4DHAPI--merit deeper investigation as promising potent and selective anticancer agents.
Asunto(s)
Aldehídos/química , Antineoplásicos/farmacología , Hidrazonas/química , Quelantes del Hierro/química , Quelantes del Hierro/farmacología , Aldehídos/farmacología , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Ácido Ascórbico/metabolismo , Caspasas/metabolismo , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Deferoxamina/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Células HL-60 , Humanos , Hidrazonas/farmacología , Cetonas/química , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Oxidación-ReducciónRESUMEN
Catecholamines are stress hormones and sympathetic neurotransmitters essential for control of cardiac function and metabolism. However, pathologically increased catecholamine levels may be cardiotoxic by mechanism that includes iron-catalyzed formation of reactive oxygen species. In this study, five iron chelators used in clinical practice were examined for their potential to protect cardiomyoblast-derived cell line H9c2 from the oxidative stress and toxicity induced by catecholamines epinephrine and isoprenaline and their oxidation products. Hydroxamate iron chelator desferrioxamine (DFO) significantly reduced oxidation of catecholamines to more toxic products and abolished redox activity of the catecholamine-iron complex at pH 7.4. However, due to its hydrophilicity and large molecule, DFO was able to protects cells only at very high and clinically unachievable concentrations. Two newer chelators, deferiprone (L1) and deferasirox (ICL670A), showed much better protective potential and were effective at one or two orders of magnitude lower concentrations as compared to DFO that were within their clinically relevant plasma levels. Ethylenediaminetetraacetic acid (EDTA), dexrazoxane (ICRF-187, clinically approved cardioprotective agent against anthracycline-induced cardiotoxicity) as well as selected beta adrenoreceptor antagonists and calcium channel blockers exerted no effect. Hence, results of the present study indicate that small, lipophilic and iron-specific chelators L1 and ICL670A can provide significant protection against the oxidative stress and cardiomyocyte damage exerted by catecholamines and/or their reactive oxidation intermediates. This potential new application of the clinically approved drugs L1 and ICL670A warrants further investigation, preferably using more complex in vivo animal models.
Asunto(s)
Cardiotónicos/farmacología , Cardiotoxinas/toxicidad , Catecolaminas/toxicidad , Quelantes del Hierro/farmacología , Miocitos Cardíacos/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Animales , Cardiotoxinas/antagonistas & inhibidores , Catecolaminas/antagonistas & inhibidores , Línea Celular , Miocitos Cardíacos/metabolismo , Oxidación-Reducción/efectos de los fármacos , Estrés Oxidativo/fisiología , RatasRESUMEN
Oxidative stress is known to contribute to a number of cardiovascular pathologies. Free intracellular iron ions participate in the Fenton reaction and therefore substantially contribute to the formation of highly toxic hydroxyl radicals and cellular injury. Earlier work on the intracellular iron chelator salicylaldehyde isonicotinoyl hydrazone (SIH) has demonstrated its considerable promise as an agent to protect the heart against oxidative injury both in vitro and in vivo. However, the major limitation of SIH is represented by its labile hydrazone bond that makes it prone to plasma hydrolysis. Hence, in order to improve the hydrazone bond stability, nine compounds were prepared by a substitution of salicylaldehyde by the respective methyl- and ethylketone with various electron donors or acceptors in the phenyl ring. All the synthesized aroylhydrazones displayed significant iron-chelating activities and eight chelators showed significantly higher stability in rabbit plasma than SIH. Furthermore, some of these chelators were observed to possess higher cytoprotective activities against oxidative injury and/or lower toxicity as compared to SIH. The results of the present study therefore indicate the possible applicability of several of these novel agents in the prevention and/or treatment of cardiovascular disorders with a known (or presumed) role of oxidative stress. In particular, the methylketone HAPI and nitro group-containing NHAPI merit further in vivo investigations.
Asunto(s)
Aldehídos/química , Antioxidantes/química , Hidrazonas/química , Quelantes del Hierro/síntesis química , Aldehídos/sangre , Aldehídos/farmacología , Animales , Antioxidantes/metabolismo , Antioxidantes/farmacología , Línea Celular , Estabilidad de Medicamentos , Hidrazonas/sangre , Hidrazonas/farmacología , Hidrólisis , Radical Hidroxilo/toxicidad , Quelantes del Hierro/metabolismo , Quelantes del Hierro/farmacología , Estrés Oxidativo , Conejos , RatasRESUMEN
This paper presents a systematic study of the retention behavior of a model bisdioxopiperazine drug, dexrazoxane (DEX) and its three polar metabolites (two single open-ring intermediates-B and C and an EDTA-like active compound ADR-925) on different stationary phases intended for hydrophilic interaction liquid chromatography (HILIC). The main aim was to estimate advantages and limitations of HILIC in the simultaneous analysis of a moderately lipophilic parent drug and its highly polar metabolites, including positional isomers, under MS compatible conditions. The study involved two bare silica columns (Ascentic Express HILIC, Atlantis HILIC) and two stationary phases with distinct zwitterionic properties (Obelisc N and ZIC HILIC). The chromatographic conditions (mobile phase strength and pH, column temperature) were systematically modified to assess their impact on retention and separation of the studied compounds. It was found that the bare silica phases were unable to separate the positional isomers (intermediates B and C), whereas both columns with zwitterionic properties (Obelisc N and ZIC HILIC) were able to separate these structurally very similar compounds. However, only ZIC HILIC phase allowed appropriate separation of DEX and all its metabolites to a base line within a single run. A mobile phase composed of a mixture of ammonium formate (0.5 mM) and acetonitrile (25:75, v/v) was suggested as optimal for the simultaneous analysis of DEX and its metabolites on ZIC HILIC. Thereafter, HILIC-LC-MS analysis of DEX and all its metabolites was performed for the first time to obtain basic data about the applicability of the suggested chromatographic conditions. Hence, this study demonstrates that HILIC could be a viable solution for the challenging analysis of moderately polar parent drug along with its highly polar metabolites including the ability to separate structurally very similar compounds, such as positional isomers.
Asunto(s)
Cromatografía Liquida/métodos , Etilenodiaminas/aislamiento & purificación , Glicina/análogos & derivados , Modelos Químicos , Razoxano/aislamiento & purificación , Fármacos Cardiovasculares/química , Fármacos Cardiovasculares/aislamiento & purificación , Etilenodiaminas/química , Glicina/química , Glicina/aislamiento & purificación , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Razoxano/química , Espectrometría de Masas en Tándem , TemperaturaRESUMEN
Salicylaldehyde isonicotinoyl hydrazone (SIH) is an iron-chelating aromatic hydrazone with promising pharmacological properties. However, it suffers from relatively short biological half-life. Hence, two novel derivates of SIH, HAP-INH and HPP-INH were synthesized in order to overcome this pharmacokinetic drawback. The aim of the present study was to employ HPLC-DAD and HPLC-MS/MS methods to investigate the identity of the putative impurities of these newly prepared substances, which are being formed in aqueous environment. At first, it was shown that their retention times as well as UV spectra did not correspond to any expected synthetic precursor, by-product or degradation product. HPLC-DAD analysis confirmed purity of peaks and revealed close but not identical UV spectra of putative impurities and corresponding hydrazones. The subsequent HPLC-MS/MS analyses using ESI and the ion trap mass analyzer showed the identical molecular ions (in both modes) as well as their fragmentation, which implicated presence of geometric isomers. This suggestion was further supported by the NMR analyses. Since the Z/E isomers can have different biological activities, results of this study might be of great importance for further development of the aroylhydrazones as novel drug candidates as well as from the theoretical point of view.