Natural Products as Potential Antiviral Drugs: The Specific Case of Marine Biotoxins.

To fight against various viral infections researchers turned to new chemical structures resulting from natural medicinal plants and more recently from "marine origin" as sources of active molecules against viral infections. The present manuscript describes complex marine origin drugs, their chemical complex structure, their therapeutic use, and their antiviral properties. Emphasis is placed more particularly on the properties of ionic channels (Na, K, Ca) blockers compounds from marine origin, named , derived from "dinoflagellates microalgae".

From 'molecules of life' to new therapeutic approaches, an evolution marked by the advent of artificial intelligence: the cases of chronic pain and neuropathic disorders.

The large families of the molecules of life are at the origin of the discovery of new compounds with which to treat disease. The arrival of artificial intelligence (AI) has considerably modified the search for innovative bioactive drugs and their therapeutic applications. Conventional approaches at different organizational research levels have emerged and, thus, AI associated with gene and cell therapies could supplant conventional pharmacotherapy and facilitate the diagnosis of pathologies.

ER stress in temozolomide-treated glioblastomas interferes with DNA repair and induces apoptosis.

Glioblastoma multiforme (GBM) is a deadly grade IV brain tumor. Radiation in combination with temozolomide (TMZ), the current chemotherapeutic for GBMs, only provides 12-14 months survival post diagnosis. Because GBMs are dependent on both activation of the DNA damage pathway and the endoplasmic reticulum (ER) stress response, we asked if a novel ER stress inducing agent, JLK1486, increases the efficacy of TMZ.

And if the discovery of new drugs for the treatment of brain diseases depends on Asian countries?

At the present time, developed countries are making a huge financial effort to support neuroscience research programs, particularly in the fields of advanced research and treatment of brain diseases and mental disorders. A part of this financial support is devoted to drug discovery programs. The purpose of this communication is to focus on the different parameters (economic, social, and scientific) allowing for the prominent belief that the discovery of new efficient drugs to treat brain disease to an increasing extent is likely to emanate from the Asian countries.

Therapeutic links between Alzheimer's disease and brain cancer: drug discovery consequences.

It was recently reported that female survivors of breast cancer have a lower risk of Alzheimer's disease (AD). This observation led to the hypothesis that there is a link between cancer and AD. This Viewpoint provides an analysis of the consequences of this hypothesis, not only from the perspective of drug discovery for new treatments, but above all, the awareness that any AD chemotherapy will require drug administration over longer periods of time before any cognitive effects are observed.

Novel phenyl(thio)ureas bearing (thio)oxothiazoline group as potential BACE-1 inhibitors: synthesis and biological evaluation.

We report the synthesis and the β-site amyloid precursor protein cleaving enzyme-1 inhibitory properties of novel phenyl(thio)ureas bearing 2-(thio)oxothiazoline derivatives. A library of analogues was prepared according to specific synthetic schemes and the inhibitory activity was monitored using a fluorescence resonance energy transfer assay. Several analogues show potent inhibitory activities ranging between 1 and 0.

Why as a medicinal chemist I am not optimistic about the possibility of finding, in a reasonable timeframe, small-molecule drugs capable of curing the evolution of Alzheimer's disease.

Herein I explain why I feel that new and effective Alzheimer's disease (AD) drugs cannot emerge from current developed concepts such as the amyloid pathway, or acetylcholinesterase inhibitors. The discovery of new therapeutic approaches first requires an understanding of the intimate structure of brain matter, where memory and cognition are located, and how aging alters its structure and function. Only by joining the expertise of quantum physicists and physical chemists with that of medicinal chemists, pharmacologists, biologists and medical doctors can new AD research orientations emerge.

Quinone methides and their prodrugs: a subtle equilibrium between cancer promotion, prevention, and cure.

The importance of reactive drug metabolites in the pathogenesis of drug-induced toxicity has been investigated since the early 1950s, mainly to reveal the link between toxic metabolites and chemical carcinogenesis. This review mainly focuses on biologically active compounds, which generate reactive quinone methide (QM) intermediates either directly or after bioactivation. Several examples of anticancer drugs acting through the generation of QM electrophiles are given.

JLK1486, a Bis 8-Hydroxyquinoline-Substituted Benzylamine, Displays Cytostatic Effects in Experimental Gliomas through MyT1 and STAT1 Activation and, to a Lesser Extent, PPARγ Activation.

Gliomas account for 5% to 7% of all solid cancers in adults and up to 30% of solid cancers in children; glioblastomas are the most malignant type of glioma and often have dismal prognoses. The alkylating agent temozolomide provides the greatest chemotherapeutic benefits currently available; however, glioblastoma patients cannot be cured. Novel drugs that efficiently combat glioblastomas are therefore of great interest.

Alternative responses of primary tumor cells and glioblastoma cell lines to N,N-bis-(8-hydroxyquinoline-5-yl methyl)-benzyl substituted amines: cell death versus P53-independent senescence.

N,N-bis-(8-hydroxyquinoline-5-yl methyl)-benzyl substituted amines (HQNBA) represent a new class of compounds showing anti-cancer activity. At the chemical level the compounds were shown to react preferentially with thiol radicals which may lead to unfolded cysteine containing proteins and subsequent ER-stress. At the molecular level, treatment of U87 cells with this class of derivatives induced an over-expression of stress genes, including P53 and numerous P53 target genes.

N,N-Bis-(8-hydroxyquinoline-5-yl methyl)-benzyl substituted amines (HQNBA): peroxisome proliferator-activated receptor (PPAR-γ) agonists with neuroprotective properties.

We report on the neuroprotective effects of N,N-bis-(8-hydroxyquinoline-5-yl methyl)-benzyl substituted amines (HQNBA) in a model of oxidative stress-induced nerve cell death using mouse hippocampal-derived HT22 cells. The four derivatives (JLK1472, JLK1486, JLK1522 and JLK1535) protected the HT22 cells from death at concentrations ranging from 0.1 to 1 μM.

Simple di- and trivanillates exhibit cytostatic properties toward cancer cells resistant to pro-apoptotic stimuli.

A series of 33 novel divanillates and trivanillates were synthesized and found to possess promising cytostatic rather than cytotoxic properties. Several compounds under study decreased by >50% the activity of Aurora A, B, and C, and WEE1 kinase activity at concentrations <10% of their IC(50) growth inhibitory ones, accounting, at least partly, for their cytostatic effects in cancer cells and to a lesser extent in normal cells. Compounds 6b and 13c represent interesting starting points for the development of cytostatic agents to combat cancers, which are naturally resistant to pro-apoptotic stimuli, including metastatic malignancies.

Neuroprotective effects of N-alkyl-1,2,4-oxadiazolidine-3,5-diones and their corresponding synthetic intermediates N-alkylhydroxylamines and N-1-alkyl-3-carbonyl-1-hydroxyureas against in vitro cerebral ischemia.

Herein we report the synthesis and neuroprotective effects of new N-alkyl-1,2,4-oxadiazolidine-3,5-diones and their corresponding synthetic intermediates, N-alkylhydroxylamines and N-1-alkyl-3-carbonyl-1-hydroxyureas, in an in vitro model of ischemia. We found five analogues that protect HT22 cells from death in the concentration range of 1-5 muM. Because members of the MAP kinase family are known to be key players in nerve cell survival and death, we characterized the role of these kinases in the neuroprotective mechanisms of the newly synthesized analogues.

Structure-activity relationships and mechanism of action of antitumor bis 8-hydroxyquinoline substituted benzylamines.

A series of twenty six 8-hydroxyquinoline substituted amines, structurally related to compounds 2 and 3, were synthesized to evaluate the effects of structural changes on antitumor activity and understand their mechanism of action. The studies were performed on a wide variety of cancer cell lines within glioma and carcinoma models. The results obtained from chemical models and biological techniques such as microarrays suggest the following hypothesis that a quinone methide intermediate which does not react with DNA but which gives covalent protein thiol adducts.

Potential neuroprotective drugs in cerebral ischemia: new saturated and polyunsaturated lipids coupled to hydrophilic moieties: synthesis and biological activity.

The ganglioside GM1 has neuroprotective effects but is not of therapeutic value because of its lack of bioavailability. Thus, molecules that mimic GM1 represent a novel approach to neuroprotection. We have synthesized 19 small GM1-like analogues whose simplified structure includes a hydrophobic saturated or unsaturated moiety linked to a hydrophilic moiety.

A new Met inhibitory-scaffold identified by a focused forward chemical biological screen.

The receptor tyrosine kinase Met is crucial for the genetic program causing cancer progression and metastasis. Its nodal function during aggressiveness and resistance acquisition poses Met inhibition as an obligatory step in anti-cancer targeted therapy. Here, we applied a "Met-focussed" forward chemical biological screen to discover new agents antagonizing Met-triggered biological functions.

Discovery of a new family of bis-8-hydroxyquinoline substituted benzylamines with pro-apoptotic activity in cancer cells: synthesis, structure-activity relationship, and action mechanism studies.

Bis-8-hydroxyquinoline substituted benzylamines have been synthesized and screened for their antitumor activity on KB3 cell line model. Synthesis of this series of new analogues was accomplished using a one pot specific methodology which allows the synthesis of both bis- and mono-8-hydroxyquinoline substituted benzylamines. Among the synthesized compounds two compounds (4a and 5a), respectively, named JLK 1472 and JLK 1486, were particularly potent on KB3 cell line.

Synthesis and biological activity of phosphonate analogues and geometric isomers of the highly potent phosphoantigen (E)-1-hydroxy-2-methylbut-2-enyl 4-diphosphate.

Gammadelta-T-lymphocytes contribute to innate immunity and are selectively activated by nonpeptide phosphorylated molecules (so-called phosphoantigens) produced by organisms responsible for causing a broad range of infectious diseases. gammadelta-T-cells are also activated by synthetic phosphoantigens and are cytotoxic to tumor cells. Here we report the synthesis, NMR characterization, and comparative biological evaluation of new pyrophosphate, phosphonate, and pyrophosphonate monoesters whose structures correspond to isosteric analogues and stereoisomers of the highly potent isoprenoid metabolite ( E)-1-hydroxy-2-methylbut-2-enyl 4-diphosphate called HDMAPP (hydroxy-dimethyl-allyl pyrophosphate).

Discovery of new small molecules that influence neuroblast cell migration from the subventricular zone.

Using SVZ (subventricular zone) tissue explants from one-day-old mice, we investigated the activity of new amino aromatic disulfide analogues and polyazamacrocycles on the migration of SVZ cells (neuroblasts). We found that among the tested analogues, non-peptidic disulfide derivative 8 significantly decreases the migration of neuroblasts from SVZ cells, and antagonized the stimulating activity of disulfide cyclic peptide 1. Discovery of compounds 1 and 8 constitutes new chemical tools which could be used to understand the mechanism of neuroblast migration during neurogenesis and eventually to identify specific genes involved in the neurogenesis.

Synthesis and anti-HIV properties of new hydroxyquinoline-polyamine conjugates on cells infected by HIV-1 LAV and HIV-1 BaL viral strains.

To find new derivatives that block different virus strains entry in cells bearing specific surface receptors represent an interesting challenge for medicinal chemists. Here, we report the synthesis and the anti-HIV properties of a new series of analogues based on the introduction of quinoline moiety on various polyamine backbones, including polyazamacrocycles. Three compounds 7, 8, and 10 of this series were found active on PBMCs cells infected by HIV-1 LAV or by HIV-1 BaL, in contrast the well-known reference compound 1a (AMD 3100) was found only active on HIV-1 LAV strain.

Naphthyl and coumarinyl biarylpiperazine derivatives as highly potent human beta-secretase inhibitors. Design, synthesis, and enzymatic BACE-1 and cell assays.

Twenty novel beta-secretase inhibitors containing biarylpiperazine moieties belonging to naphthyl and coumarinyl series were designed for their potential use in Alzheimer's disease therapy. Enzymatic and cell-based assays have been carried out. The biological results clearly demonstrate that specific substituents located at the N(4)-position of the piperazine ring result in excellent in vitro inhibitory potency (IC(50) values ranging between 40 and 70 nM).

Imino-tetrahydro-benzothiazole derivatives as p53 inhibitors: discovery of a highly potent in vivo inhibitor and its action mechanism.

Several neurological disorders manifest symptoms that result from the degeneration and death of specific neurons. p53 is an important modulator of cell death, and its inhibition could be a therapeutic approach to several neuropathologies. Here, we report the design, synthesis, and biological evaluation of novel p53 inhibitors based on the imino-tetrahydrobenzothiazole scaffold.

1,1'-Xylyl bis-1,4,8,11-tetraaza cyclotetradecane: a new potential copper chelator agent for neuroprotection in Alzheimer's disease. Its comparative effects with clioquinol on rat brain copper distribution.

Dysfunction of copper metabolism leading to its excess or deficiency results in severe ailments. Recently, neurodegenerative disorders such as Alzheimer's disease have been associated with copper metabolism. Compounds having the ability to reduce copper levels in brain or to affect its distribution could have neuroprotective effects, mainly through a downregulation of the transcription of amyloid peptide precursor (APP).

BACE-1 inhibitory activities of new substituted phenyl-piperazine coupled to various heterocycles: chromene, coumarin and quinoline.

The protease beta-secretase plays a central role in the synthesis of pathogenic amyloid-beta in Alzheimer's disease. Here, we report a new series of analogues based on the phenyl-piperazine scaffold coupled to various heterocyclic moieties, which demonstrate improved inhibitory activities on BACE-1 (FRET assay) compared to already known naphthyl counterparts. The obtained results suggest further structural modifications to access to more potent BACE-1 inhibitors.