The Proof-of-Concept of MBA121, a Tacrine-Ferulic Acid Hybrid, for Alzheimer's Disease Therapy.

Great effort has been devoted to the synthesis of novel multi-target directed tacrine derivatives in the search of new treatments for Alzheimer's disease (AD). Herein we describe the proof of concept of MBA121, a compound designed as a tacrine-ferulic acid hybrid, and its potential use in the therapy of AD. MBA121 shows good ß-amyloid (Aß) anti-aggregation properties, selective inhibition of human butyrylcholinesterase, good neuroprotection against toxic insults, such as Aß1-40, Aß1-42, and H2O2, and promising ADMET properties that support translational developments. A passive avoidance task in mice with experimentally induced amnesia was carried out, MBA121 being able to significantly decrease scopolamine-induced learning deficits. In addition, MBA121 reduced the Aß plaque burden in the cerebral cortex and hippocampus in APPswe/PS1ΔE9 transgenic male mice. Our in vivo results relate its bioavailability with the therapeutic response, demonstrating that MBA121 is a promising agent to treat the cognitive decline and neurodegeneration underlying AD.

New contributions to the drug profile of TNFα inhibitor SPD304: Affinity, selectivity and ADMET considerations.

Tumor necrosis factor alpha (TNFα) is a relevant clinical target for the treatment of chronic inflammatory diseases. Currently, only few small molecules are known as direct inhibitors of TNFα. To date, none of these molecules has shown both an efficient activity and a low toxicity to be considered for clinical trials. The SPD304 is considered as a reference of direct inhibitors of TNFα because of its well demonstrated mechanism (He et al., 2005). Herein, we provide new insights regarding the drug profile, selectivity and absorption, distribution, metabolism, excretion and toxicity (ADMET) considerations of SPD304 to evaluate its potential as a hit for the structure-based design of novel TNFα inhibitors. ELISA experiments confirmed the inhibition of TNFα/TNF receptor 1 binding (IC50 = 12 µM). Cellular-based assays highlighted the cytotoxicity of SPD304, as well as its ability to inhibit TNFα signaling pathways at non-cytotoxic concentrations. A surface acoustic wave (SAW) experiment highlighted only one binding site with a dissociation constant of 6.1 ± 4.7 nM. SPD304 inhibited the binding of the cytokines like interleukins (IL)-4 and IL-13 to their receptors and showed no direct inhibition on proteins involved in the TNFα pathway. Finally, the thermodynamic solubility and Caco-2 cells permeability of SPD304 were experimentally evaluated and ADMET in silico predictions are also discussed. The physicochemical, pharmacological and ADMET studies of SPD304 have shown that is not an ideal hit for a drug optimization program based on its chemical structure.

Azetidinimines as a novel series of non-covalent broad-spectrum inhibitors of ß-lactamases with submicromolar activities against carbapenemases KPC-2 (class A), NDM-1 (class B) and OXA-48 (class D).

The occurrence of resistances in Gram negative bacteria is steadily increasing to reach extremely worrying levels and one of the main causes of resistance is the massive spread of very efficient ß-lactamases which render most ß-lactam antibiotics useless. Herein, we report the development of a series of imino-analogues of ß-lactams (namely azetidinimines) as efficient non-covalent inhibitors of ß-lactamases. Despite the structural and mechanistic differences between serine-ß-lactamases KPC-2 and OXA-48 and metallo-ß-lactamase NDM-1, all three enzymes can be inhibited at a submicromolar level by compound 7dfm, which can also repotentiate imipenem against a resistant strain of Escherichia coli expressing NDM-1. We show that 7dfm can efficiently inhibit not only the three main clinically-relevant carbapenemases of Ambler classes A (KPC-2), B (NDM-1) and D (OXA-48) with Ki's below 0.3 µM, but also the cephalosporinase CMY-2 (class C, 86% inhibition at 10 µM). Our results pave the way for the development of a new structurally original family of non-covalent broad-spectrum inhibitors of ß-lactamases.

Discovery of simplified benzazole fragments derived from the marine benzosceptrin B as necroptosis inhibitors involving the receptor interacting protein Kinase-1.

With the aim to develop new chemical tools based on simplified natural metabolites to help deciphering the molecular mechanism of necroptosis, simplified benzazole fragments including 2-aminobenzimidazole and the 2-aminobenzothiazole analogs were prepared during the synthesis of the marine benzosceptrin B. Conpounds inhibiting the RIPK1 protein kinase were discovered. A library of 54 synthetic analogs were prepared and evaluated through a phenotypic screen using the inhibition of the necrotic cell death induced by TNF-α in human Jurkat T cells deficient for the FADD protein. This article reports the design, synthesis and biological evaluation of a series of 2-aminobenzazoles on the necroptotic cell death through the inhibition of RIPK1 protein kinase. The 2-aminobenzimidazole and 2-aminobenzothiazole platforms presented herein can serve as novel chemical tools to study the molecular regulation of necroptosis and further develop lead drug candidates for chronic pathologies involving necroptosis.

Multitarget Therapeutic Strategies for Alzheimer's Disease: Review on Emerging Target Combinations.

Neurodegenerative diseases represent nowadays one of the major health problems. Despite the efforts made to unveil the mechanism leading to neurodegeneration, it is still not entirely clear what triggers this phenomenon and what allows its progression. Nevertheless, it is accepted that neurodegeneration is a consequence of several detrimental processes, such as protein aggregation, oxidative stress, and neuroinflammation, finally resulting in the loss of neuronal functions. Starting from these evidences, there has been a wide search for novel agents able to address more than a single event at the same time, the so-called multitarget-directed ligands (MTDLs). These compounds originated from the combination of different pharmacophoric elements which endowed them with the ability to interfere with different enzymatic and/or receptor systems, or to exert neuroprotective effects by modulating proteins and metal homeostasis. MTDLs have been the focus of the latest strategies to discover a new treatment for Alzheimer's disease (AD), which is considered the most common form of dementia characterized by neurodegeneration and cognitive dysfunctions. This review is aimed at collecting the latest and most interesting target combinations for the treatment of AD, with a detailed discussion on new agents with favorable in vitro properties and on optimized structures that have already been assessed in vivo in animal models of dementia.

Subtype Selective γ-Aminobutyric Acid Type A Receptor (GABAAR) Modulators Acting at the Benzodiazepine Binding Site: An Update.

γ-Aminobutyric acid (GABA) is the major inhibitory neurotransmitter within the central nervous system (CNS) with fast, transsynaptic, and modulatory extrasynaptic effects being mediated by the ionotropic GABA type A receptors (GABAARs). These receptors are of particular interest because they are the molecular target of a number of pharmacological agents, of which the benzodiazepines (BZDs), such as diazepam, are the best described. The anxiolytic, sedating, and myorelaxant effects of BZDs are mediated by separate populations of GABAARs containing either α1, α2, α3, or α5 subunits and the molecular dissection of the pharmacology of BZDs indicates that subtype-selective GABAAR modulators will have novel pharmacological profiles. This is best exemplified by α2/α3-GABAAR positive allosteric modulators (PAMs) and α5-GABAAR negative allosteric modulators (NAMs), which were originally developed as nonsedating anxiolytics and cognition enhancers, respectively. This review aims to summarize the current state of the field of subtype-selective GABAAR modulators acting via the BZD binding site and their potential clinical indications.

Synthesis and Biological Evaluation of Novel Chromone+Donepezil Hybrids for Alzheimer's Disease Therapy.

BACKGROUND: Many factors are involved in Alzheimer's Disease (AD) such as amyloid plaques, neurofibrillary tangles, cholinergic deficit and oxidative stress. To counter the complexity of the disease the new approach for drug development is to create a single molecule able to act simultaneously on different targets. OBJECTIVE: We conceived eight drug likeliness compounds targeting the inhibition of cholinesterases and the scavenging of radicals. METHODS: We synthesised the new molecules by the Passerini multicomponent reaction and evaluated their inhibitory activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) as well as their antioxidant activities by the Oxygen Radical Absorbance Capacity (ORAC) assay. The lipinski's rule for drug likeness and in silico ADME prediction was also performed. RESULTS: Compounds 4f [IC50 (EeAChE) = 0.30 µM; IC50 (eqBuChE) = 0.09 µM; ORAC = 0.64 TE] and 4h [IC50 (EeAChE) = 1 µM; IC50 (eqBuChE) = 0.03 µM; ORAC = 0.50 TE] were identified as hits for further development. CONCLUSION: The Passerini reaction allowed us the facile synthesis of ditarget molecules of interest for the treatment of AD.

Synthesis, antioxidant and Aß anti-aggregation properties of new ferulic, caffeic and lipoic acid derivatives obtained by the Ugi four-component reaction.

We report herein the synthesis antioxidant and Aß anti-aggregation capacity of (E)-N-benzyl-N-[2-(benzylamino)-2-oxoethyl]-3-(aryl)acrylamides and related (R)-N-benzyl-N-(2-(benzylamino)-2-oxoethyl)-5-(1,2-dithiolan-3-yl)pentanamides 1-12. These compounds have been obtained, via Ugi four-component reaction, from modest to good yields. Their antioxidant analysis, using the DPPH and ORAC assays, allowed us to identify compounds 8 and 9, as potent antioxidant agents, showing also strong Aß1-40 self-aggregation inhibition, two biological properties of interest in pathologies linked to the oxidative stress, such as Alzheimer's disease.

A fluorine scan of a tubulin polymerization inhibitor isocombretastatin A-4: Design, synthesis, molecular modelling, and biological evaluation.

A novel series of tubulin polymerization inhibitors, based on fluorinated derivatives of isocombretastatin A-4 was synthesized with the goal of evaluating the effect of these compounds on the proliferative activity. The introduction of fluorine atom was performed on the phenyl ring or at the linker between the two aromatic rings. The modification of isoCA-4 by introduction of difluoromethoxy group at the para-position (3i) and substitution of the two protons of the linker by two fluorine atoms (3m), produced the most active compounds in the series, with IC50 values of 0.15-2.2 nM (3i) and 0.1-2 nM (3m) respectively, against a panel of six cancer cell lines. Compounds 3i and 3m had greater antiproliferative activity in comparison with references CA-4 or isoCA-4, the presence of fluorine group leads to a significant enhancement of the antiproliferative activity. Molecular docking studies indicated that compounds 3i and 3m occupy the colchicine binding site of tubulin. Evaluation of cytotoxicity in Human noncancer cells indicated that the compounds 3i and 3m were practically ineffective in quiescent peripheral blood lymphocytes, and may have a selective antiproliferative activity against cancer cells. Analyses of cell cycle distribution, and morphological microtubules organization showed that compound 3m induced G2/M phase arrest and, dramatically disrupted the microtubule network.

Base-Mediated Generation of Ketenimines from Ynamides: Direct Access to Azetidinimines by an Imino-Staudinger Synthesis.

Ynamides were used as precursors for the in situ generation of highly reactive ketenimines that could be trapped with imines in a [2+2] cycloaddition. This imino-Staudinger synthesis led to a variety of imino-analogs of ß-lactams, namely azetidinimines (20 examples), that could be further functionalized through a broad range of transformations.

Multitarget compounds bearing tacrine- and donepezil-like structural and functional motifs for the potential treatment of Alzheimer's disease.

Alzheimer's disease is a multifactorial and fatal neurodegenerative disorder characterized by decline of cholinergic function, deregulation of other neurotransmitter systems, ß-amyloid fibril deposition, and ß-amyloid oligomers formation. Based on the involvement of a relevant number of biological systems in Alzheimer's disease progression, multitarget compounds may enable therapeutic efficacy. Accordingly, compounds possessing, besides anticholinergic activity and ß-amyloid aggregation inhibition properties, metal chelating and/or nitric oxide releasing properties with additional antioxidant capacity were developed. Other targets relevant to Alzheimer's disease have also been considered in the last years for producing multitarget compounds such as ß-secretase, monoamino oxidases, serotonin receptors and sigma 1 receptors. The purpose of this review will be to highlight recent reports on the development of multitarget compounds for Alzheimer's disease published within the last years focusing on multifunctional ligands characterized by tacrine-like and donepezil-like structures.

The Antioxidant Additive Approach for Alzheimer's Disease Therapy: New Ferulic (Lipoic) Acid Plus Melatonin Modified Tacrines as Cholinesterases Inhibitors, Direct Antioxidants, and Nuclear Factor (Erythroid-Derived 2)-Like 2 Activators.

Novel multifunctional tacrines for Alzheimer's disease were obtained by Ugi-reaction between ferulic (or lipoic acid), a melatonin-like isocyanide, formaldehyde, and tacrine derivatives, according to the antioxidant additive approach in order to modulate the oxidative stress as therapeutic strategy. Compound 5c has been identified as a promising permeable agent showing excellent antioxidant properties, strong cholinesterase inhibitory activity, less hepatotoxicity than tacrine, and the best neuroprotective capacity, being able to significantly activate the Nrf2 transcriptional pathway.

Synthesis and Biological Evaluation of Benzochromenopyrimidinones as Cholinesterase Inhibitors and Potent Antioxidant, Non-Hepatotoxic Agents for Alzheimer's Disease.

We report herein the straightforward two-step synthesis and biological assessment of novel racemic benzochromenopyrimidinones as non-hepatotoxic, acetylcholinesterase inhibitors with antioxidative properties. Among them, compound 3Bb displayed a mixed-type inhibition of human acetylcholinesterase (IC50 = 1.28 ± 0.03 µM), good antioxidant activity, and also proved to be non-hepatotoxic on human HepG2 cell line.

Bone metastasis from malignant phyllodes breast tumor: report of two cases.

BACKGROUND: Phyllodes tumors are rare fibroepithelial tumors accounting for less than 1 % of all breast neoplasms. They are malignant in 20 % of cases. Only a few cases of malignant phyllodes tumors metastatic to bone have been reported. CASE PRESENTATION: Case 1: A 40 year-old white woman presented with three-week history of pain and functional impairment of the left lower limb. Her clinical past was remarkable for previous left mastectomy and radiotherapy for malignant phyllodes tumor performed one year ago. Computed tomography revealed a moth-eaten appearance of the left femoral head. The patient underwent computed guided femoral head biopsy. Pathological findings were consistent with metastatic malignant phyllodes tumor. The patient received ifosfamide and adriamycin chemotherapy. She is doing well without any evidence of progression on her imaging follow- up after 8 months. Case 2: A 48 year-old white woman, with history of bilateral mastectomy and radiotherapy for malignant phyllodes tumor performed one and two year ago, presented with four-week left lower quadrant abdominal pain. Computed tomography and magnetic resonance imaging revealed a solid aggressive osteolytic mass of the left iliac bone with extensive soft tissue invasion. Biopsy of the tumor was performed and showed a sarcomatous proliferation consistent with metastatic malignant phyllodes tumor. The patient received the same chemotherapy regimen as in the first case but without any response on her imaging follow up after 6 months. CONCLUSION: Malignant phyllodes tumor is a rare and aggressive fibroepithelial neoplasm. An accurate diagnosis of metastases should be based on clinicopathological correlation allowing exclusion of differential diagnoses. The goal of successful managing this tumor is early detection and complete resection prior to dissemination.

Synthesis and Biological Assessment of Racemic Benzochromenopyrimidinimines as Antioxidant, Cholinesterase, and Aß1-42 Aggregation Inhibitors for Alzheimer's Disease Therapy.

Given the complex nature of Alzheimer's disease (AD), compounds that are able to simultaneously address two or more AD-associated targets show greater promise for development into drugs for AD therapy. Herein we report an efficient two-step synthesis and biological evaluation of new racemic benzochromene derivatives as antioxidants, inhibitors of cholinesterase and ß-amyloid (Aß1-42 ) aggregation. Based on the results of the primary screening, we identified 15-(3-methoxyphenyl)-9,11,12,15-tetrahydro-10H,14H-benzo[5,6]chromeno[2,3-d]pyrido[1,2-a]pyrimidin-14-imine (3 e) and 16-(3-methoxyphenyl)-9,10,11,12,13,16-hexahydro-15H-benzo[5',6']chromeno[2',3':4,5]pyrimido[1,2-a]azepin-15-imine (3 f) as new potential multitarget-directed ligands for AD therapy. Further in-depth biological analysis showed that compound 3 f is a good human acetylcholinesterase inhibitor [IC50 =(0.36±0.02) µm], has strong antioxidant activity (3.61 µmol Trolox equivalents), and moderate Aß1-42 antiaggregating power (40.3 %).

Donepezil-ferulic acid hybrids as anti-Alzheimer drugs.

BACKGROUND: Due to the complex nature of Alzheimer's disease, there is a renewed and growing search for multitarget drugs. RESULTS: Donepezil-ferulic acid hybrids (DFAHs) were prepared by the one-pot Ugi-4CR in low-to-moderate yields. DFAHs are potent antioxidant agents, showing oxygen radical absorbance capacity values in the range 4.80-8.71 trolox equivalents, quite higher compared with those recorded for ferulic acid and melatonin. From the ChEs inhibition studies, we conclude that DFAH 8, bearing an ethylene linker, and DFAH 12, bearing a propylene linker, both substituted with a melatonin motif, are the most potent inhibitors, in the nanomolar range. CONCLUSION: We have identified DFAH 8 as a very potent antioxidant, and totally selective equineButyrylCholinEsterase (eqBuChE) inhibitor.

Novel tacrine-grafted Ugi adducts as multipotent anti-Alzheimer drugs: a synthetic renewal in tacrine-ferulic acid hybrids.

Herein we describe the design, multicomponent synthesis, and biological, molecular modeling and ADMET studies, as well as in vitro PAMPA-blood-brain barrier (BBB) analysis of new tacrine-ferulic acid hybrids (TFAHs). We identified (E)-3-(hydroxy-3-methoxyphenyl)-N-{8[(7-methoxy-1,2,3,4-tetrahydroacridin-9-yl)amino]octyl}-N-[2-(naphthalen-2-ylamino)2-oxoethyl]acrylamide (TFAH 10 n) as a particularly interesting multipotent compound that shows moderate and completely selective inhibition of human butyrylcholinesterase (IC50 =68.2 nM), strong antioxidant activity (4.29 equiv trolox in an oxygen radical absorbance capacity (ORAC) assay), and good ß-amyloid (Aß) anti-aggregation properties (65.6 % at 1:1 ratio); moreover, it is able to permeate central nervous system (CNS) tissues, as determined by PAMPA-BBB assay. Notably, even when tested at very high concentrations, TFAH 10 n easily surpasses the other TFAHs in hepatotoxicity profiling (59.4 % cell viability at 1000 µM), affording good neuroprotection against toxic insults such as Aß1-40 , Aß1-42 , H2 O2 , and oligomycin A/rotenone on SH-SY5Y cells, at 1 µM. The results reported herein support the development of new multipotent TFAH derivatives as potential drugs for the treatment of Alzheimer's disease.