1,2-Benzothiazine derivatives: antibacterial and antifungal activity with structure-activity relationship insights.

Androgen deprivation therapy (ADT) remains the primary treatment for advanced prostate cancer. However, most patients relapse within 18-24 months, progressing to castration-resistant prostate cancer (CRPC) which is currently incurable. Our preliminary studies identified the arylpiperazine derivative NAF19 as a promising therapeutic agent against prostate cancer, though its precise mechanisms remained unclear. This study aims to systematically evaluate the antitumor effects of NAF19 in prostate cancer cells and elucidate its molecular mechanisms, with a focus on its multi‑target inhibition of the AR/AR‑Vs signaling pathway and key survival pathways. To evaluate the effects of NAF19 on prostate cancer cell growth, we treated a panel of prostate cancer cell lines (LNCaP, C4-2, 22Rv1, DU145, and PC-3) representing both androgen-sensitive and castration-resistant phenotypes (including AR-expressing and AR-null subtypes) with varying concentrations of NAF19 for 72 h. Cell viability and sensitivity were subsequently assessed using the CCK-8 assay. In LNCaP and 22Rv1 cells, we further performed qRT-PCR to analyze the mRNA expression levels of AR/AR-Vs and their downstream target genes (PSA and UBE2C), flow cytometry to determine cell cycle distribution, and western blotting to examine the levels of cleaved PARP, antiapoptotic Bcl-2 family proteins, phosphorylated AKT (at Ser473 and Thr308), phosphorylated ERK, phosphorylated S6, as well as total AR and AR-V7. To assess the impact of NAF19 on tumor cell metastatic potential and proliferation, transwell migration and invasion assays, along with EdU incorporation assays, were conducted. Furthermore, a luciferase reporter assay was carried out to evaluate the transcriptional activity of the androgen receptor (AR). NAF19 exhibited growth-inhibitory effects across all five prostate cancer cell lines. It significantly suppressed AR/AR-Vs downstream gene expression, induced G1-phase cell cycle arrest in 22Rv1 cells, and reduced anti-apoptotic Mcl-1 protein levels while activating apoptosis. NAF19 dose-dependently induced PARP cleavage; NAF19 significantly reduced the phosphorylation levels of AKT (at T308 and S473 sites), ERK, and S6. Functional assays confirmed marked suppression of migration, invasion, and proliferation in NAF19-treated cells. The novel arylpiperazine derivative NAF19 exerts multi-targeted antitumor effects by concurrently inhibiting AR/AR-Vs signaling pathways and activating apoptotic cascades, thereby potently suppressing the migratory, invasive, and proliferative capacities of prostate cancer cells.

The majority of patients with androgen-dependent prostate cancer (PCa) develop resistance to hormone therapy after approximately 18-24months of androgen deprivation therapy treatment. During this process, PCa cells progressively lose their sensitivity to androgens and evolve into castration-resistant prostate cancer leading to uncontrolled tumor growth and ultimately the failure of endocrine therapy. To develop potential anti-prostate cancer agents, in this study, we identified a novel ether-type arylpiperazine derivative as a potent androgen receptor (AR) antagonist, uncovering a series of effective antiproliferative compounds. The derivatives (7, 11, 17, 19, 20, 21, 22, 23, and 24) demonstrated strong cytotoxicity against cancer cells, with 17, 19, 20, and 23 showing significant androgen receptor antagonistic activity (Inhibition% >60) and robust AR binding affinities. The structure-activity relationship (SAR) of these developed derivatives was discussed based on data. Docking study suggested that the compound 19 mainly bind to AR ligand binding pocket site through Van der Waals' force interactions. This research presents a promising lead compound for developing anticancer agents targeting prostate cancer therapy.

Unravelling the mechanism of tyrosinase inhibition by arylpiperidine and arylpiperazine derivatives: A computational approach

Background: In recent decades, there has been a startling rise in the number of cancer patients worldwide, which has led to an amazing upsurge in the development of novel anticancer treatment candidates. On a positive note, arylpiperazines have garnered attention in cancer research due to their potential as scaffolds for developing anticancer agents. These compounds exhibit a diverse array of biological activities, including cytotoxic effects against cancer cells. Indeed, one of the key advantages of arylpiperazines lies in their ability to interact with various molecular targets implicated in cancer pathogenesis. Aim: Here, we focus on the chemical structures of several arylpiperazine derivatives, highlighting their anti-proliferative activity in different tumor cell lines. The modular structure, diverse biological activities, and potential for combination therapies of arylpiperazine compounds make them valuable candidates for further preclinical and clinical investigations in the fight against cancer. Conclusion: This review, providing a careful analysis of different arylpiperazines and their biological applications, allows researchers to refine the chemical structures to improve potency, selectivity, and pharmacokinetic properties, thus advancing their therapeutic potential in oncology.

Herein, a series of novel arylpiperazine (piperidine) derivatives were designed, synthesized, and evaluated for mechanisms of action through in vitro and in vivo studies. The most promising compound, II-13 (later named as MT-1207), is a potent α1 and 5-HT2A receptor antagonist with remarkable IC50 in the picomolar level. Importantly, in the in vivo assay, II-13 achieved an effective blood pressure (BP) reduction in the 2K2C rat model without damaging renal function. Compound II-13, with its significant advantages in terms of pharmacological effects, pharmacokinetic parameters, and a large safety window, was extensively investigated. Moreover, data also showed that compound II-13 had fewer side effects in a postural BP assay and could prevent the onset of postural hypotension. Together, these results suggested that compound II-13 is a highly potent antihypertensive drug candidate with multitarget mechanisms of action in preclinical models. Currently, MT-1207 is in phase II hypertensive clinical trials in China.

A novel arylpiperazine derivative (LQFM181) protects against neurotoxicity induced by 3- nitropropionic acid in in vitro and in vivo models

Serotonin, or 5-hydroxytryptamine (5-HT), is a biogenic amine most noted as a neurotransmitter, an activator of the utmost subtype family of G-protein- coupled receptors (GPCR). Drugs targeting 5-HT1A and other 5-HT receptors treat central nervous system diseases such as schizophrenia and depression. Recent advances in serotonin receptor structure research gave us several crystal 5-HT1A receptor structures, most notably 5-HT1A bound to the antipsychotic drug aripiprazole (Abilify?). This discovery prompted us to evaluate a series of newly synthesized ligands for serotonergic activity since those arylpiperazine derivatives share minimal general structure with aripiprazole. The results of molecular docking analysis of unsubstituted starting substances encouraged us to propound further modifications of the tail and head parts of the parent molecules to maximize receptor binding affinity. Intrigued by the results of molecular analysis, all foreseen derivatives were synthesized. The pharmacological activity of all nine (5a and 6a are synthesized previously) compounds was assessed by the in vitro tests and in silico pharmacokinetics predictions for the most promising candidates. All tested ligands have improved affinity compering to parent compounds (10a and 11a), 8b and 9b expressed the best pharmacological profile with an improved binding affinity toward serotonin 5-HT1A receptors (Ki 12.1 and 4.8 nM, respectively).

The 5-hydroxytryptamine receptor (5-HTR) family includes seven classes of receptors. The 5-HT7R is the newest member of this family and contributes to different physiological and pathological processes. As a pathology, glioblastoma multiform (GBM) overexpresses 5-HT7R; hence, this study aims to develop radiolabeled aryl piperazine derivatives as 5-HT7R imaging agents. METHODS: Compounds 6 and 7 as 1-(3-nitropyridin-2-yl)piperazine derivatives were radiolabeled with fac-[99mTc(CO)3(H2O)3]+ and 99mTc(CO)3-[6] and 99mTc(CO)3-[7] were obtained with high radiochemical purity (RCP > 94%).The stability of the radiotracers was evaluated in both saline and mouse serum. Specific binding on different cell lines including U-87 MG, MCF-7, SKBR3, and HT-29 was performed. The biodistribution of these radiotracers was evaluated in normal and U-87 MG Xenografted models. Finally, 99mTc(CO)3-[6] and 99mTc(CO)3-[7] were applied for in vivo imaging in U-87 MG Xenografted models. Specific binding study indicates that 99mTc(CO)3-[6] and 99mTc(CO)3-[7] can recognize 5-HT7R of U87-MG cell line. The biodistribution study in normal mice indicates that the brain uptake of 99mTc(CO)3-[6] and 99mTc(CO)3-[7] is the highest at 30min post-injection (0.8 ± 0.25 and 0.64 ± 0.18%ID/g, respectively). The data of the biodistribution study in the U87-MG xenograft model revealed that these radiotracers could accumulate in the tumor site, and the highest tumor uptake was observed at 60min post-injection (3.38 ± 0.65 and 3.27 ± 0.5%ID/g, respectively). The injection of pimozide can block the tumor's radiotracer uptake, indicating the binding of these radiotracers to the 5-HT7R. The imaging study in the xenograft model also confirms the biodistribution data. The acquired images clearly show the tumor site, and the tumor-to-muscle ratio for 99mTc(CO)3-[6] and 99mTc(CO)3-[7] at 60min was 3.33 and 3.88, respectively. CONCLUSIONS: 99mTc(CO)3-[6] and 99mTc(CO)3-[7] can visualize tumorin theU87-MG xenograft modeldueto their affinitytoward5-HT7R.

Background: A series of aryl-piperazine derivatives of 1,7,8,9-tetrachloro-10,10-dimethoxy-4- azatricyclo [5.2.1.02,6] dec-8-ene-3,5-dione were designed, synthesized, and their biological activities were evaluated. Methods: The chemical structures of the desired compounds were identified by 1H NMR, ESI-MS and elementary analysis. The anti-cancer and anti-angiogenesis activities of the newly synthesized compounds were evaluated by proliferation and migration assays, respectively. Results: The screening results demonstrated that compounds 2 and 5 showed potent anti-tumor activity (IC50 values ranging from 7.1 to 15.9μM) with low cytotoxic activities (IC50＞79.3μM). Although compound 5 had no effects on endothelial proliferation (IC50=65.3μM), it significantly abrogated endothelial cell migration (IC50=6.7μM). Conclusion: This work may impart new direction for the investigations of aryl-piperazine derivatives and lead to the development of potent novel anti-tumor and anti-angiogenesis agents.

Background: In the current Alzheimer’s disease therapy as the preferred treatment are applied acetylcholinesterase inhibitors. Aiming to identify the active pharmacophores necessary for increased acetylcholinesterase inhibitory activity, some docking studies have been applied. Methods: In silico docking evaluation of the binding modes, identification of acetylcholinesterase inhibitory activity in vitro through Ellman’s test and ITC protocol, and the in vivo effect. PAMPA evaluation of the GIT and BBB permeability. Results: In the present study, two series previously synthesized in our laboratory, arylpiperazine derivatives of theobromine were docked into the rhAChE active sites. Ellman’s test outlined molecules LA1 and LA7 as the most active, with IC50 of 0.708 and 0.299 μM, respectively. In the acute toxicity test, LA7 given intraperitoneally in mice showed moderate toxicity with LD50 of 87.5 mg/kg. The new compound, administered i.p. for 12 days at doses 2 mg/kg/day and 4 mg/kg/day, respectively, showed a pronounced acetylcholinesterase inhibitory activity in vivo. Conclusion: The corresponding binding modes were identified, where the docking pose for the studied molecules depends on the protonated state of the nitrogen atom of the piperazine moiety. In the best scored pose for LA7, the xanthine moiety is bound into the catalytic active site (CAS) of acetylcholinesterase, while the arylpiperazine fragment is placed into the peripheral binding site (PAS). For the evaluated selected structures, good permeability through the GIT and BBB assessed by PAMPA was also determined.

Synthesis and evaluation of 99mTc-labeled 1-(2-Pyridyl)piperazine derivatives as radioligands for 5HT7 receptors

Depression, anxiety, and schizophrenia may coexist in psychiatric patients. Moreover, these disorders are very often associated with cognitive impairments. However, pharmacotherapy of these conditions remains challenging due to limited drug effectiveness or numerous side effects. Therefore, there is an urgent need to develop novel multimodal compounds that can be used to treat depression, anxiety, and schizophrenia, as well as memory deficits. Thus, this study aimed to evaluate the potential antidepressant-like, anxiolytic-like, antipsychotic-like effects, and anti-amnesic properties, of the novel arylpiperazine derivative of salicylamide, JJGW07, with an affinity towards serotonin 5-HT1A, 5-HT2A, and 5-HT7 and dopamine D2 receptors. Firstly, we investigated the compound's affinity for 5-HT6 receptors and its functional activity by using in vitro assays. JJGW07 did not bind to 5-HT6 receptors and showed antagonistic properties for 5-HT1A, 5-HT2A, 5-HT7, and D2 receptors. Based on the receptor profile, we performed behavioral studies in mice to evaluate the antidepressant-like, anxiolytic-like, and antipsychotic-like activity of the tested compound using forced swim and tail suspension tests; four-plate, marble-burying, and elevated plus maze tests; and MK-801- and amphetamine-induced hyperlocomotion tests, respectively. JJGW07 revealed antidepressant-like properties in the tail suspension test, anxiolytic-like effects in the four-plate and marble-burying tests, and antipsychotic-like activity in the MK-801-induced hyperlocomotion test. Importantly, the tested compound did not induce catalepsy and motor impairments or influence locomotor activity in rodents. Finally, to assess the potential procognitive and anti-amnesic properties of JJGW07, we used passive avoidance and object recognition tests in mice. JJGW07 demonstrated positive effects on long-term emotional memory and also ameliorated MK-801-induced emotional memory impairments in mice, but showed no procognitive properties in the case of recognition memory. Our results encourage the search for new compounds among salicylamide derivatives, which could be model structures with multitarget mechanisms of action that could be used in psychiatric disorder therapy.

Cardiovascular diseases remain one of the leading causes of death worldwide. Unfortunately, the available pharmacotherapeutic options have limited effectiveness. Therefore, developing new drug candidates remains very important. We selected six novel arylpiperazine alkyl derivatives of salicylamide to investigate their cardiovascular effects. Having in mind the beneficial role of α1-adrenergic receptors in restoring sinus rhythm and regulating blood pressure, first, using radioligand binding assays, we evaluated the affinity of the tested compounds for α-adrenergic receptors. Our experiments revealed their high to moderate affinity for α1- but not α2-adrenoceptors. Next, we aimed to determine the antiarrhythmic potential of novel derivatives in rat models of arrhythmia induced by adrenaline, calcium chloride, or aconitine. All compounds showed potent prophylactic antiarrhythmic activity in the adrenaline-induced arrhythmia model and no effects in calcium chloride- or aconitine-induced arrhythmias. Moreover, the tested compounds demonstrated therapeutic antiarrhythmic activity, restoring a normal sinus rhythm immediately after the administration of the arrhythmogen adrenaline. Notably, none of the tested derivatives affected the normal electrocardiogram (ECG) parameters in rodents, which excludes their proarrhythmic potential. Finally, all tested compounds decreased blood pressure in normotensive rats and reversed the pressor response to methoxamine, suggesting that their hypotensive mechanism of action is connected with the blockade of α1-adrenoceptors. Our results confirm the antiarrhythmic and hypotensive activities of novel arylpiperazine derivatives and encourage their further investigation as model structures for potential drugs.

Prostate cancer is one of the malignant tumors and the second most common malignant tumor in men. Clinically used androgen receptor (AR)–targeted drugs can antagonize androgen and inhibit tumor growth, but these drugs can cause serious resistance problems. To develop novel AR antagonists, 22 kinds of arylpiperazine derivatives were designed and synthesized, and the derivatives 5, 8, 12, 19, 21, 22, 25, and 26 not only showed strong antagonistic potency (>55% inhibition) and binding affinities (IC50 <3 μM) to AR, but also showed stronger inhibitory activity to LNCaP cells versus PC-3 cells. Among them, derivative 21 exhibited the highest binding affinity for AR (IC50 = 0.65 μM) and the highest antagonistic potency (76.2% inhibition). Docking studies suggested that the derivative 21 is primarily bound to the AR-LBP site by the hydrophobic interactions. Overall, those results provided experimental methods for developing novel arylpiperazine derivatives as potent AR antagonists.

Neurological disorders are disease conditions related to the neurons and central nervous system (CNS). Any structural, electrical, biochemical, and functional abnormalities in neurons can lead to various types of disorders, like Alzheimer's disease (AD), depression, Parkinson's disease (PD), epilepsy, stroke, etc. Currently available medicines are symptomatic and do not treat the disease state. Thus, novel CNS active agents with the potential to completely treat an illness are highly desired. A range of small organic molecules is being explored as potential drug candidates to cure different neurological disorders. In this context, arylpiperazinehas been found to be a versatile scaffold and indispensable pharmacophore in many CNS active agents. Several molecules with arylpiperazine nucleus have been developed as potent leads for the treatment of AD, PD, depression, and other disorders. The arylpiperazine nucleus can be optionally substituted at different chemical structures and offer flexibility for the synthesis of a large number of derivatives. In the current review article, we have explored the role of various arylpiperazine containing scaffolds against different neurological disorders, including AD, PD, and depression. The structure-activity relationship studies were conducted for recognizing potent lead compounds. This review article may provide important insights into the structural requirements for designing and synthesizing effective molecules as curative agents for different neurological disorders.

Long-chain arylpiperazine scaffold is a versatile template to design central nervous system (CNS) drugs that target serotonin and dopamine receptors. Here we describe the synthesis and biological evaluation of ten new arylpiperazine derivatives designed to obtain an affinity profile at serotonin 5-HT1A, 5-HT2A, 5-HT7 receptor, and dopamine D2 receptor of prospective drugs to treat the core symptoms of autism spectrum disorder (ASD) or psychosis. Besides the structural features required for affinity at the target receptors, the new compounds incorporated structural fragments with antioxidant properties to counteract oxidative stress connected with ASD and psychosis. All the new compounds showed CNS MultiParameter Optimization score predictive of desirable ADMET properties and cross the blood–brain barrier. We identified compound 12a that combines an affinity profile compatible with antipsychotic activity (5-HT1AKi = 41.5 nM, 5-HT2AKi = 315 nM, 5-HT7Ki = 42.5 nM, D2Ki = 300 nM), and compound 9b that has an affinity profile consistent with studies in the context of ASD (5-HT1AKi = 23.9 nM, 5-HT2AKi = 39.4 nM, 5-HT7Ki = 45.0 nM). Both compounds also had antioxidant properties. All compounds showed low in vitro metabolic stability, the only exception being compound 9b, which might be suitable for studies in vivo.

One-pot synthesis of novel substituted quinoxaline piperazine derivatives and their antimicrobial activities

A total of 20 novel aryl piperazine derivatives were designed and synthesized, and their structures were confirmed by mass spectrometry and nuclear magnetic resonance analyses. Their 5-HT1A and sigma-1 receptor affinities were determined, and six of them showed high affinities (K i &lt; 20 nmol/L) to both 5-HT1A and sigma-1 targets. Then, metabolic stability (T 1/2) tests of six compounds in rat and human liver microsomes were performed. Our data indicated that compound 27 has both high affinity for 5-HT1A and sigma-1 receptors (5-HT1A: K i = 0.44 nmol/L; sigma-1: K i = 0.27 nmol/L), and good metabolic stability (T 1/2 values are 21.7 and 24.6 minutes, respectively). Interestingly, results from the forced swimming test, mouse tail suspension test, and preliminary pharmacokinetic test suggested the marked antidepressant activity, good pharmacokinetic characteristics, and low toxicity of compound 27 in the two models. In conclusion, compound 27 has great value of further study as an active molecule of antidepressant drugs.

Design and synthesis of new potent 5-HT7 receptor ligands as a candidate for the treatment of central nervous system diseases