Combining eugenol and dihydroeugenol with a piperazine moiety to create new antimicrobial agents that are effective against resistant species.

Historically, the piperazine moiety has been demonstrated to possess pharmacophoric properties, and has subsequently been incorporated in many drugs that have antitumor, antimalarial, antiviral, antibacterial and antifungal properties. Derivatives of eugenol and dihydroeugenol have also been reported as being bioactive compounds. This study reports the synthesis of a range of eugenol/dihydroeugenol - piperazine derivatives which have been tested as antimicrobial compounds against Gram positive, Gram negative and rapid-growing mycobacteria (RGM). The rationale employed in the design of the structural pattern of these new derivatives, provides useful insights into the structure-activity relationships (SAR) of the series. Antimicrobial activity tests were extremely encouraging, with the majority of the synthesised compounds being more active than eugenol and dihydroeugenol starting materials. The antimicrobial potential was most notable against the Gram-negative species K. pneumoniae and P. aeruginosa, but there was also significant performance against the Gram-positive strains S. epidermidis and S. aureus and the Rapidly Growing Mycobacteria (RGM) strains tested. Tests using the synthesised compounds against multidrug-resistance clinical (MDR) isolates also showed high activity. The biofilm inhibition tests using M. fortuitum showed that all evaluated derivatives were able to inhibit biofilm formation even at low concentrations. In terms of structural-activity relationships; the results generated by this study demonstrate that the compounds with bulky substituents on the piperazine subunit were much more active than those with less bulky groups, or no groups. Importantly, the derivatives with a sulfonamide side chain were the most potent compounds. A further observation was that those compounds with a para-substituted benzenesulfonamide ring stand out, regardless of whether this substituent is a donor or an electron-withdrawing group.

Preclinical pharmacokinetics of a promising antineoplastic prototype piperazine-containing compound (LQFM018) in rats by a new LC-MS/MS bioanalytical method.

LQFM018 is a novel antineoplastic prototype, showing an expressive drug-triggered K562 leukemic cells death mechanism, through necroptotic signaling. Due to its promising effect, this study aimed to evaluate the pharmacokinetics of LQFM018 in rats, using a new validated bioanalytical LC-MS/MS-based method. Chromatographic column was an ACE® C18 (100 mm × 4.6 mm, 5 µm) eluted by a mobile phase composed of ammonium acetate 2 mM and formic acid 0.025%:methanol (50:50, v/v), under flow of 1.2 mL/min and injection volume of 3.0 µL. LQFM018 was extracted from rat plasma by a simple liquid-liquid method, using MTBE solvent. Rats were administered intraperitoneally at LQFM018 100 mg/kg dose and blood samples were collect at times of 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 h. Bioanalytical-LC-MS/MS-based method was rapid, high throughput and sensitive with a good linearity ranging from 10 (LLOQ) to 15000 ng/mL, besides precise and accurate, ranging of 0.8-7.3% and 96.8-107.6%, respectively. The prototype LQFM018 was rapid and well absorbed, and highly distributed, apparently due to its high lipid solubility. These features are primordial for an anticancer agent in the treatment of deep tumors, such as bone marrow neoplasms, in which the drug might permeate easily tissue barriers. Also, LQFM018 has demonstrated a high clearance, according to a low t1/2in rats, indicating a relative fast elimination phase related to a possible intense hepatic biotransformation. These information support further studies to establish new understands on pharmacokinetics of promising antineoplastic prototype LQFM018 from preclinical and clinical evaluations.

Antiparasitic action of ivermectin, moxidectin and piperazine against Parascaris spp. in foals at southern Rio Grande do Sul, Brazil / Ação antiparasitária de Ivermectina, Moxidectina e Piperazina contra Parascaris spp. em potros no sul do Rio Grande do Sul, Brasil

Parascaris spp. are the most dangerous parasites of foals, and their presence is related to poor growth, weight loss, colics and death after impaction or intestinal perforation.The reduction in the effectiveness of antiparasitics has become a serious threat to animal health and there is little prospect of the emergence of a new anthelmintic for horses. Therefore, the objective was to evaluate the effectiveness of active principles used in the control of ascarids in Creole foals, in a ownership located in the south of Rio Grande do Sul, Brazil. The Gordon and Whitlock technique was used on 12 samples of foal faeces that were collected on the date of administration of the antiparasitic and 14 days afterwards. The evaluation of the effectiveness of the active principles was carried out through the Faecal Egg Count Reduction Test (FECRT). All the anthelmintics used failed against Parascaris spp. and therefore should not be used to control infections caused by these helminths in the population studied. In addition, generalized resistance of ascarids to avermectins was observed. The results also show that other management practices should be implemented on the ownership, in an attempt to reduce infections by these helminths.

Parascaris spp. são os parasitas mais perigosos dos potros e estão relacionados ao baixo crescimento, perda de peso, cólicas e morte após impactação ou perfuração intestinal. A redução da eficácia dos antiparasitários tornou-se uma séria ameaça à saúde animal e há poucas perspectivas de surgimento de um novo anti-helmíntico para equinos. Portanto, objetivou-se avaliar a eficácia dos princípios ativos utilizados no controle de ascarídeos em potros crioulos, em uma propriedade localizada no sul do Rio Grande do Sul, Brasil. Foram utilizados os resultados da técnica de Gordon e Whitlock de 12 amostras de fezes de potros, que foram coletadas na data da administração do antiparasitário e 14 dias após. A avaliação da eficácia dos princípios ativos foi realizada por meio do Teste de Redução de Contagem de Ovos nas Fezes (TRCOF). Todos os anti-helmínticos utilizados falharam contra Parascaris spp. e não devem ser usados para controlar as infecções desses helmintos na população estudada, além disso, há uma resistência generalizada dos ascarídeos contra as avermectinas. Os resultados também mostram que outras práticas de manejo devem ser implementadas na propriedade, na tentativa de reduzir as infecções por esses helmintos.

Modifications in the piperazine ring of nucleozin affect anti-influenza activity.

The infection caused by the influenza virus is a latent tret. The limited access to vaccines and approved drugs highlights the need for additional antiviral agents. Nucleozin and its analogs have gain attention for their promising anti-influenza activity. To contribute to the advancement of the discovery and design of nucleozin analogs, we analyzed piperazine-modified nucleozin analogs to increase conformational freedom. Also, we describe a new synthetic strategy to obtain nucleozin and its analogues, three molecules were synthesized and two of them were biologically evaluated in vitro. Although the analogues were less active than nucleozin, the loss of activity highlights the need for the piperazine ring to maintain the activity of nucleozin analogs. Interestingly, this result agrees with the prediction of anti-influenza activity made with a QSAR model presented in this work. The proposed model and the synthetic route will be useful for the further development of nucleozin analogs with antiviral activity.

Neurotoxicity Assessment of 1-[(2,3-Dihydro-1-Benzofuran-2-yl)Methyl]Piperazine (LINS01 Series) Derivatives and their Protective Effect on Cocaine-Induced Neurotoxicity Model in SH-SY5Y Cell Culture.

Excessive levels of dopamine in the synaptic cleft, induced by cocaine for example, activates dopaminergic receptors, mainly D1R, D2R, and D3R subtypes, contributing to neurotoxic effects. New synthetic 1-[(2,3-dihydro-1-benzofuran-2-yl)methyl]piperazine derivatives (the LINS01 compounds), designed as histaminergic receptor (H3R) ligands, are also dopaminergic receptor ligands, mainly D2R and D3R. This study aims to evaluate the neurotoxicity of these new synthetic LINS01 compounds (LINS01003, LINS01004, LINS01011, and LINS01018), as well as to investigate their protective potential on a cocaine model of dopamine-induced neurotoxicity using SH-SY5Y cell line culture. Neurotoxicity was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase (LDH), and automated cell counting with fluorescent dyes (acridyl orange and propidium iodide) assays. Concentration-response curves (CRCs) were performed for all LINS compounds and cocaine using MTT assay. The results show that LINS series did not decrease cell viability after 48h of exposure-except for 100 µM LINS01018, which was discontinued from the study. Likewise, MTT, LDH, and fluorescent dyes staining showed no difference is cell viability for LINS compounds at 10 µM. When incubated with 2.5 mM cocaine (lethal concentration 50) for 48h, 10 µM of each LINS compound, metoclopramide (D2R antagonist) and haloperidol (D2R/D3R antagonist), ameliorated cocaine-induced neurotoxicity. However, only metoclopramide, haloperidol, and LINS01011 compound significantly decreased LDH released in the culture medium, suggesting that this new synthetic compound presents a more robust effect. This preliminary in vitro neurotoxicity study suggests that LINS01 compounds are not neurotoxic, and that they play a promising role in preventing cocaine-induced neurotoxicity.

Structure-activity relationship of three new piperazine derivates with anxiolytic-like and antidepressant-like effects.

Anxiety and depression are common mental disorders affecting millions of people worldwide. Unsatisfactory clinical outcomes with the use of the available pharmacological interventions among some patients demand newer drugs with proven efficacy, safety, and tolerability profile. In this study, the LQFM211, LQFM213, and LQFM214 were designed from the piperazine scaffold and administered orally in mice. These mice were later evaluated in the open field, elevated plus maze, and forced swimming tests to assess the exploratory, anxiolytic, and antidepressant-like activities, respectively. The mechanism of action of these new derivatives was evaluated using flumazenil (benzodiazepine antagonist) and WAY100635 (5-HT1A receptor antagonist). Unlike LQFM214, the LQFM211 and LQFM213 elicited anxiolytic and antidepressant-like effects. The blockade of the effect of LQFM213 by WAY100635 suggests the involvement of the serotonergic pathway.

Potential of 1-(1-napthylmethyl)-piperazine, an efflux pump inhibitor against cadmium-induced multidrug resistance in Salmonella enterica serovar Typhi as an adjunct to antibiotics.

This study was focused on elucidating inhibition of antibiotic efflux mechanism of cadmium adapted (CdA) Salmonella Typhi Ty2 cells. Herein, upregulated expression of efflux genes (acrB, tolC) and their regulators (soxS, marA) was observed in CdA Ty2 cells by qRT-PCR. The pathogen further elevated the expression of these genes even in the presence of three efflux pump inhibitors (EPIs), i.e., Phe-Arg-ß-naphthylamide, 1-(1-naphthyl-methyl)piperazine, and 5-hydroxy-2-methyl-1,4-naphthoquinone, perhaps by sensing the pressure of the latter in addition to cadmium stress. Interaction of different EPIs with efflux pumps of CdA Ty2 cells was confirmed using ethidium bromide (EtBr) accumulation and efflux assay. All the EPIs could cause retention of EtBr which was indicated by increased fluorescence units. Considering this potential of EPIs, retention of antibiotics was evaluated in CdA Ty2 cells wherein EPIs were used in combination with selected antibiotics (instead of EtBr). A decrease in the effective concentration of antibiotics was observed. This was further validated using the clinical isolates. The data revealed the efficiency of EPIs as they could inhibit the efflux potential of even the overexpressed efflux pumps. Thus, combination of EPI(s)-antibiotics may be exploited in future as one of the strategies for combating metal induced antibiotic resistance.

Identification and Quantification of a Phytotoxic Metabolite from Alternaria dauci.

Alternaria dauci is the causal agent of Alternaria leaf blight (ALB) in carrot (Daucus carota) crops around the world. However, to date, A. dauci has received limited attention in its production of phytotoxic metabolites. In this investigation, the bioassay-guided isolation of the extract from liquid cultures of A. dauci resulted in the isolation of two metabolites identified as α-acetylorcinol (1) and p-hydroxybenzoic acid (2), based on their spectroscopic data and results from chemical correlation reactions. Testing of both metabolites in different assays showed an important phytotoxic activity for p-hydroxybenzoic acid (2) when tested in the leaf-spot assay on parsley (Petroselinum crispum), in the leaf infiltration assay on tobacco (Nicotiana alata) and marigold (Tagetes erecta), and in the immersion assay on parsley and parsnip (Pastinaca sativa) leaves. Quantification of the two metabolites in the crude extract of A. dauci kept at different times showed that p-hydroxybenzoic acid (2) is one of the first metabolites to be synthesized by the pathogen, suggesting that this salicylic acid derivative could play an important role in the pathogenicity of the fungus.

The tea-bag protocol for comparison of Fmoc removal reagents in solid-phase peptide synthesis.

Several factors have influenced the increasing presence of peptides as an important class of Active Pharmaceutical Ingredients. One is the continued development of synthetic methodologies for peptide synthesis. Herein, we investigated the Fmoc removal step, using the tea-bag strategy. In this regard, three different secondary amines: piperidine, 4-methylpiperidine, and piperazine, were evaluated. As a result of this study, 4-methyl piperidine showed to be an excellent alternative to the usually used piperidine in terms of purity and compliance with green chemistry principles as well.

Neuropharmacological assessment in mice and molecular docking of piperazine derivative LQFM212.

Piperazine derivatives are an attractive class of chemical compounds for the treatment of various mental illness. Herein, we demonstrated the synthesis of LQFM212, a piperazine derivative, behavioral evaluation in mice and computational studies. In neuropharmacological assessment, LQFM212 treatment at doses of 18, 54 or 162 µmol/kg increased the sleep duration in sodium pentobarbital-induced sleep test. LQFM212 at dose of 162 µmol/kg increased climbing time in the chimney test and decreased the number of squares crossed in the open field test, suggesting that LQFM212 in high doses reduces spontaneous movement. However, LQFM212 treatment at the doses of 18 or 54 µmol/kg increased the preference for the center of field which could be indicative of anxiolytic-like effects. In elevated plus maze and light-dark box tests, LQFM212 treatment altered all parameters observed that demonstrate anxiolytic-like activity. These effects were reversed by flumazenil, mecamylamine, WAY-100635 and PCPA, but not with ketanserin, showing that anxiolytic-like activity involve benzodiazepine site of GABAA receptor, nicotinic and serotonergic pathways. Molecular docking of LQFM212 showed that the ligand has more interactions with GABAA receptor than with 5-HT1A receptor. Despite the involvement of benzodiazepine site on anxiolytic-like effect of LQFM212, treatment with this compound did not alter cognitive function in the step-down avoidance test. In this sense, this piperazine derivative is a good prototype for treating anxiety disorders with putative mechanism of action.

Piperazine ring formation by a single-module NRPS and cleavage by an α-KG-dependent nonheme iron dioxygenase in brasiliamide biosynthesis.

Brasiliamides are a class of piperazine-containing alkaloids produced by Penicillium brasilianum with a range of pharmaceutical activities. The mechanism of brasiliamide biosynthesis, including piperazine ring formation and multiple tailoring modifications, still remains unclear. In this study, the biosynthetic gene cluster of brasiliamides, brs, was identified from the marine-derived fungal strain Penicillium brasilianum WZXY-M122-9. Deletion of a histone deacetylase-encoding gene using a CRISPR/Cas9 gene editing system led to the production of a new compound, namely brasiliamide I (1). The brs-encoded single-module nonribosomal peptide synthetase (NRPS) BrsA is involved in the formation of the piperazine skeleton of brasiliamides. Full-length BrsA protein (113.6 kDa) was purified, and reconstitution of enzymatic activity in vitro confirmed that BrsA stereoselectively accepts L-phenylalanine as the substrate. Multiple deletion of tailoring genes and analysis of purified proteins in vitro enabled us to propose a brasiliamide biosynthetic pathway. In the tailoring steps, an α-ketoglutarate (KG)-dependent nonheme iron dioxygenase, BrsJ, was identified to catalyze piperazine ring cleavage during biosynthesis of brasiliamide A (2). KEY POINTS: The gene cluster encoding brasiliamide biosynthesis, brs, is identified. Deletion of a histone deacetylase-encoding gene produces brasiliamide I. BrsA catalyzes brasiliamide piperazine skeleton formation. BrsJ catalyzes piperazine ring cleavage to produce brasiliamide A. Graphical abstract.

Estudio de las propiedades moleculares y reactivas del antibiótico Ciprofloxacina a nivel de teoría de funcional de densidad DFT B3LYP/6- 31G* / Study of the molecular and reactive properties of the antibiotic Ciprofloxacin at the level of functional density theory DFT B3LYP / 6-31G*

INTRODUCCIÓN: se realizó un estudio teórico computacional de la ciprofloxacina calculando detalladamente las propiedades moleculares del mismo. Se caracterizó este antibiótico, presentado valores de longitudes de enlace y ángulos, así como de propiedades químicas de interés en estudios QSAR, de energías y de reactividad, obtenidos por métodos mecano cuánticos utilizando la teoría funcional de densidad DFT B3LYP/6-31G*. OBJETIVO: determinar las propiedades moleculares, de QSAR y de reactividad de la Ciprofloxacina usando el método teórico de cálculo denominado: Teoría del Funcional de la Densidad (DFT) MÉTODO: la estructura de la ciprofloxacina fue trazada usando la interfaz de SPARTAN; esta fue sometida a cálculos de optimización geométrica inicialmente de Mecánica Molecular para obtener la estructura más estable, posteriormente todas las estructuras fueron analizadas utilizando la teoría de Hartree-Fock para obtener valores más confiables de energía y geometría. Posteriormente sobre estas estructuras se aplica la Teoría de Funcional de Densidad DFT usándose la base 6-31G*. Con esta estructura se realizaron cálculos de energía en conjunto con un análisis de población natural (NPA) para la molécula neutra e ionizada (positiva y negativa) para determinar los centros nucleofílicos, electrofílicos y radicalarios, y obtener posteriormente los descriptores de la reactividad local y las funciones de Fukui nucleofílica y electrofílica. RESULTADOS: Los valores experimentales de longitud de enlace para los enlaces C=C aromático del fenilo de 1.400 Å, respecto a longitudes de enlace C(10q)-C(5)=1.401 Å y C(8)- C(9q)=1.406 Å mostraron diferencias de 0.001 y 0.006. El enlace característico con el flúor F-C aromático reportado de 1.363Å, respecto al calculado en este estudio de 1.353Å muestra una diferencia de 0.01 del valor experimental. La longitud de enlace N1 de la quinolina y el C9 del ciclopropil reportado con 1.465Å y el calculado 1.450Å muestra una diferencia de 0.015. La longitud de enlace experimental C=O aromático de 1.230Å respecto al encontrado O(3)-C(4) de 1.227Å, muestra una diferencia de 0.003. Finalmente, en el anillo piperazina la longitud experimental C-N reportado de 1.465 Å, la calculada 1.463 Å diferencia de 0.002 De acuerdo con los datos calculados y reportados experimentalmente, se puede concluir que existe una buena correlación en los valores de las longitudes de enlace a nivel DFT B3LYP/6-31G*. Los ángulos entre átomos de carbono del sistema aromático encontrados en la ciprofloxacina oscilan entre 120.02° a 122.27°, en relación al valor teórico de este tipo de átomos de carbono con hibridación sp2 cuentan con un ángulo de 120°. En cuanto a la reactividad química, los índices descriptores de reactividad química global y local, el orbital HOMO es el dador y el orbital LUMO el aceptor. Un band-gap de 4.65 ev indica claramente que la molécula es muy estable. CONCLUSIÓN: se establecieron valores de las propiedades moleculares y así como de propiedades químicas de interés en estudios de estructura actividad QSAR, de energías y de reactividad del antibiótico ciprofloxacina.

INTRODUCTION: a theoretical computational study of ciprofloxacin was performed, calculating in detail the molecular properties of it. This antibiotic was characterized, presenting values of link lengths and angles as well as chemical properties of interest in QSAR, energy and reactivity studies, obtained by quantum mechanic methods using the Functional Density Theory DFT B3LYP / 6-31G *. OBJECTIVE: to determine the molecular, QSAR and reactivity properties of Ciprofloxacin using the theoretical calculation method called: Density Functional Theory (DFT). METHOD: the structure of ciprofloxacin was mapped using the SPARTAN interface; This was initially subjected to calculations of geometric optimization of Molecular Mechanics to obtain the most stable structure, later all the structures were analyzed using the Hartree-Fock theory to obtain more reliable values of energy and geometry. Subsequently on these structures the DFT Density Functional Theory is applied using the 6-31G * base. With this structure, energy calculations were performed in conjunction with a natural population analysis (NPA) for the neutral and ionized molecule (positive and negative) to determine the nucleophilic, electrophilic and radical centers, and subsequently obtain the descriptors of the local reactivity and the nucleophilic and electrophilic Fukui functions. RESULTS: The experimental values of bond length for the aromatic C = C bonds of the phenyl of 1,400 Å, with respect to link lengths C (10q) -C (5) = 1,401 Å and C (8) -C (9q) = 1,406 Å showed differences of 0.001 and 0.006. The characteristic link with the reported aromatic F-C fluorine of 1,363Å, compared to that calculated in this study of 1,353Å shows a difference of 0.01 of the experimental value. The linkage length N1 of the quinoline and the C9 of the cyclopropyl reported with 1,465Å and the calculated 1,450Å shows a difference of 0.015. The experimental aromatic C = O link length of 1,230Å with respect to the found O (3) -C (4) of 1,227Å, shows a difference of 0.003. Finally, in the piperazine ring, the reported CN experimental length of 1,465 Å, the calculated 1,463 Å difference of 0.002 According to the data calculated and reported experimentally, it can be concluded that there is a good correlation in the values of the link lengths at the DFT level B3LYP / 6-31G *. The angles between carbon atoms of the aromatic system found in ciprofloxacin range from 120.02 ° to 122.27 °, in relation to the theoretical value of this type of carbon atoms with sp2 hybridization have an angle of 120 °. Regarding chemical reactivity, the indexes describing global and local chemical reactivity [2], the HOMO orbital is the donor and the LUMO orbital is the acceptor. A band-gap of 4.65 ev clearly indicates that the molecule is very stable. The chemical potential obtained for the neutral ciprofloxacin of (-3,715ev) indicates that the electronic density of the system can vary spontaneously, since it has a negative value. The hardness gave the value of 2,325ev, indicates that ciprofloxacin will have little tendency to give or receive electrons, that is, the hardness has been associated with the stability of the chemical system. CONCLUSION: molecular and chemical properties values of interest were established in QSAR activity structure studies, energies and reactivity of the antibiotic ciprofloxacin.

Tert-butyl 4-((1-phenyl-1H-pyrazol-4-yl) methyl) piperazine-1-carboxylate (LQFM104)- New piperazine derivative with antianxiety and antidepressant-like effects: Putative role of serotonergic system.

The piperazine derivatives correspond to an extensive chemical class of compounds with numerous neuropharmacological activities, including antidepressant (e.g., nefazodone, trazodone) and anxiolytic (e.g., buspirone) properties. Therefore, aiming to identify a new antidepressant and antianxiety lead-compound, our group designed, synthesized, and investigated the effects of a new piperazine compound, namely, LQFM104, on the behavior of mice. Male albino Swiss mice were treated with LQFM104 prior to predictive behavioral tests as open field (OFT), elevated plus maze (EPM), forced swimming (FST), and tail suspension tests (TST). The participation of the serotonergic system was evaluated by pretreatment with a 5-HT1A antagonist receptor (WAY100635) and serotonin (5-HT) synthesis inhibitor (p-chlorphenylalanine, pCPA) before oral administration of LQFM104 and behavioral tests. The treatment with LQFM104 did not interfere with locomotor activity but revealed suggestive data of anxiolytic-like effects by the increase in the time spent in the center of the OFT. This activity was confirmed by the results obtained in the EPM, and it was abolished after pretreatment with WAY100635 and pCPA. The immobility time decreased in both the FST and TST. The antidepressant-like activity was completely abolished after WAY100635 pretreatment. Altogether, these data revealed that LQFM104 possesses anxiolytic and antidepressant-like properties in behavioral tests on mice, and these activities are possibly mediated, directly and/or indirectly, by serotonergic pathways.

The novel piperazine-containing compound LQFM018: Necroptosis cell death mechanisms, dopamine D4 receptor binding and toxicological assessment.

Piperazine is a promising scaffold for drug development due to its broad spectrum of biological activities. Based on this, the new piperazine-containing compound LQFM018 (2) [ethyl 4-((1-(4-chlorophenyl)-1H-pyrazol-4-yl)methyl)piperazine-1-carboxylate] was synthetized and some biological activities investigated. In this work, we described its ability to bind aminergic receptors, antiproliferative effects as well as the LQFM018 (2)-triggered cell death mechanisms, in K562 leukemic cells, by flow cytometric analyses. Furthermore, acute oral systemic toxicity and potential myelotoxicity assessments of LQFM018 (2) were carried out. LQFM018 (2) was originally obtained by molecular simplification from LASSBio579 (1), an analogue compound of clozapine, with 33% of global yield. Binding profile assay to aminergic receptors showed that LQFM018 (2) has affinity for the dopamine D4 receptor (Ki = 0.26 µM). Moreover, it showed cytotoxicity in K562 cells, in a concentration and time-dependent manner; IC50 values obtained were 399, 242 and 119 µM for trypan blue assay and 427, 259 and 50 µM for MTT method at 24, 48 or 72 h, respectively. This compound (427 µM) also promoted increase in LDH release and cell cycle arrest in G2/M phase. Furthermore, it triggered necrotic morphologies in K562 cells associated with intense cell membrane rupture as confirmed by Annexin V/propidium iodide double-staining. LQFM018 (2) also triggered mitochondrial disturb through loss of ΔΨm associated with increase of ROS production. No significant accumulation of cytosolic cytochrome c was verified in treated cells. Furthermore, it was verified an increase of expression of TNF-R1 and mRNA levels of CYLD with no involviment in caspase-3 and -8 activation and NF-κB in K562 cells. LQFM018 (2) showed in vitro myelotoxicity potential, but it was orally well tolerated and classified as UN GHS category 5 (LD50 > 2000-5000 mg/Kg). Thus, LQFM018 (2) seems to have a non-selective action considering hematopoietic cells. In conclusion, it is suggested LQFM018 (2) promotes cell death in K562 cells via necroptotic signaling, probably with involvement of dopamine D4 receptor. These findings open new perspectives in cancer therapy by use of necroptosis inducing agents as a strategy of reverse cancer cell chemoresistance.

Anti-inflammatory effect of a new piperazine derivative: (4-methylpiperazin-1-yl)(1-phenyl-1H-pyrazol-4-yl)methanone.

AIMS: This study investigates the anti-nociceptive and anti-inflammatory effects of new piperazine compound (LQFM182) as well as the toxicity acute in vitro. MAIN METHODS: To evaluate the anti-nociceptive activity, the acetic acid-induced abdominal writhing test, tail flick test and formalin-induced pain test were used. The anti-inflammatory activity was evaluated using the models of paw oedema and pleurisy induced by carrageenan and some inflammatory parameters were evaluated, including cell migration, myeloperoxidase enzyme activity and the levels of TNF-α and IL-1ß cytokines in pleural exudate. The acute oral systemic toxicity of LQFM182 in mice was evaluated through the neutral red uptake (nru) assay. KEY FINDINGS: LQFM182 (50, 100 or 200 mg/kg, p.o.) decreased the number of writhings induced by acetic acid in a dose-dependent manner, and an intermediate dose (100 mg/kg, p.o.) reduced the paw licking time of animals in the second phase of the formalin test. Furthermore, LQFM182 (100 mg/kg, p.o.) reduced oedema formation at all hours of the paw oedema induced by carrageenan test and in pleurisy test reduced cell migration from the reduction of polymorphonuclear cells, myeloperoxidase enzyme activity and the levels of pro-inflammatory cytokines IL-1ß and TNF-α. Therefore, it was classified in GHS category 300 < LD50 < 2000 mg/kg. SIGNIFICANCE: Reduction of the TNF-α and IL-1ß levels.

Anti-Trichomonas vaginalis activity from triterpenoid derivatives.

Trichomonas vaginalis is a flagellated parasite that causes trichomonosis, the most common non-viral sexually transmitted disease (STD) in the world. Worryingly, trichomonosis is associated to increased transmission of HIV. Due to high frequency of the infection during pregnancy and the development of metronidazole-resistant isolates, therapeutic alternatives to 5-nitroimidazole are being searched. Triterpenes are natural products presenting several biological activities such as anti-protozoal activity. The aim of this study was to evaluate the in vitro anti-T. vaginalis activity from betulinic and ursolic acids, as well as semisynthetic derivatives obtained. Compounds obtained from betulinic acid presented better activity than those from ursolic acid. Piperazine derivatived from betulinic acid presented minimum inhibitory concentration (MIC) value of 91.2 µM, and the kinetic growth curve performed with parasites treated with this most active compound revealed complete inhibition of trophozoite proliferation at 2 h of incubation and total abolition of trophozoite growth in 24 h, revealing that the piperazine derivative is an efficient trichomonacidal molecule. The same compound promoted total erythrocyte lysis and lactate dehydrogenase (LDH) liberation of 83 and 100% (at 45.6 and 91.2 µM, respectively), indicating parasite membrane damage. The piperazine derivative demonstrated cytotoxic effect against the HMVII and HeLa cell lineages at the MIC value. This is the first report of semisynthetic triterpenoid derivatives with anti-T. vaginalis activity, revealing the high potential of these compounds as trichomonacidal agents.

Synthesis, 5-hydroxytryptamine1A receptor affinity and docking studies of 3-[3-(4-aryl-1-piperazinyl)-propyl]-1H-indole derivatives.

A series of 3-[3-(4-aryl-1-piperazinyl)-propyl]-1H-indole derivatives (12a-h) was synthesized and evaluated for binding affinity at the human 5-hydroxytryptamine(1A) receptor (5-HT(1A)R) compounds (12b) and (12h) showed the highest 5-HT(1A) receptor affinity (IC(50)=15 nM). Molecular docking studies with all the compounds in a homology model of 5-HT(1A) showed that the main interaction anchoring the ligand in the receptor was a charge-reinforced bond between the protonated nitrogen atom (N-4) of the piperazine ring and Aspartate(3.32).

Surgical diagnosis and management of intestinal obstruction due to Ascaris lumbricoides.

BACKGROUND: Ascariasis continues to be one of the most important parasitic diseases in terms of its burden and complications in children in the developing world. METHODS: Case report and literature review (Medline, SCI, and LILACS). RESULTS: We report herein a case in which a Paraguayan infant presented with one of these complications: An intestinal obstruction due to Ascaris lumbricoides being diagnosed during surgery. The patient was managed with a conservative protocol for the extraction of the parasites using liquid petrolatum administered through a nasogastric tube followed with extensive water irrigation through the tube, in conjunction with the administration of piperazine as antiparasitic treatment. CONCLUSIONS: This case, as with others reported previously, shows that this complication can be managed successfully without major intestinal surgery. Early recognition of this condition, based on local prevalence, can prevent serious surgical complications, morbidity, and mortality associated with intestinal obstruction due to A. lumbricoides.

Two-dimensional QSAR studies on arylpiperazines as high-affinity 5-HT(1A) receptor ligands.

5-HT(1A) receptor plays an important role in the delayed onset of antidepressant action of a class of selective serotonin reuptake inhibitors. Moreover, 5-HT(1A) receptor levels have been shown to be altered in patients suffering from major depression. In this work, hologram quantitative structure-activity relationship (HQSAR) studies were performed on a series of arylpiperazine compounds presenting affinity to the 5-HT(1A) receptor. The models were constructed with a training set of 70 compounds. The most significant HQSAR model (q(2) = 0.81, r(2) = 0.96) was generated using atoms, bonds, connections, chirality, and donor and acceptor as fragment distinction, with fragment size of 6-9. Predictions for an external test set containing 20 compounds are in good agreement with experimental results showing the robustness of the model. Additionally, useful information can be obtained from the 2D contribution maps.

In vitro anthelmintic activity of Melia azedarach naturalized in Argentina.

The anthelmintic activity of the drupe extracts of Melia azedarach L. (Meliaceae) growing in Argentina was tested against tapeworms, hookworms, nodular worms and earthworms, and was shown to be better than the standards piperazine phosphate and hexylresorcinol against tapeworms and hookworms, respectively.