Synthèse, dérivation et évaluation de pharmacophores hybrides Alcynyl-TriAzolyCarbinols N-glycosylés

La fonction alcényl-alcynylcarbinol (AAC) est un pharmacophore clé rencontré dans des produits naturels extraits d'éponges marines, les pétrosiacétylènes, aux propriétés biologiques multiples, en particulier une cytotoxicité remarquable sur les cellules tumorales. Le noyau 1H-1,2,3-triazole (TA) est par ailleurs un motif peptido-mimétique bien identifié dans des inhibiteurs enzymatiques, par exemple dans le Tazobacatam(r) vis-à-vis de bêtalactamases. La " fusion " -ou hybridation intime-et la glyco-conjugaison de ces deux pharmacophores est envisagée dans des structures inédites de type bis(1H-1,2,3triazolyl)carbinols (BTAC), alcynyl-triazolylcarbinols (ATAC = ATAC(y)), ou alcényltriazolylcarbinols (ATAC(e)) N-glycosylés. De telles molécules ont été synthétisées par réaction de Huisgen d'azotures de glycosyles, en position primaire ou anomérique du (D)ribose, (D)-galactose, ou (D)-glucose O-protégés, avec des substrats dialcynylcarbinols (DAC) et AAC diversement substitués en positions 1 et 3. Ces dipolarophiles de cycloaddition [2+3] se sont avérés réagir régio-sélectivement dans des conditions de chimie clic (CuSO4, 5 H2O + ascorbate de sodium, dans un mélange éthanol/eau). Le principe a été généralisé aux substrats trialcynylcarbinols, et la réactivité du produit tris(N-benzyl 1H-1,2,3triazolyl)carbinol, Taz3C-OH, a été étudiée. En présence d'anhydride trifluoroacétique, ce dernier carbinol conduit au cation tris(triazolyl)carbénium -appelé " cation trizyle " par analogie avec le cation trityle, dont la réactivité SN1 avec divers O-, N-, S- et C-nucléophiles s'est avérée sélectivement productrice de nouvelles structures, analogues hétérocycliques de dérivés du triphénylméthane connus ou non. Parmi les nouveaux composés décrits, certains ATAC et BTAC ont été sélectionnés et testés pour leur cytotoxicité sur cellules tumorales (adénocarcinome) et leur activité inhibitrice d'enzymes (a-glucosidase et sphingosine kinase). Des résultats prometteurs ont été obtenus sur l'inhibition de la sphingosine kinase SK1.The alkenyl-alkynylcarbinol function (AAC) is a key pharmacophore encountered in natural products extracted from marine sponges, the petrosiacetylenes, exhibiting various biological properties, and in particular a remarkable cytotoxicity on tumor cells. In a different context, the 1H-1,2,3-triazole (TA) core is a peptido-mimetic motif identified in several enzymatic inhitors, for example of beta-lactamases in the Tazobacatm(r) drug. The fusion -or intimate hybridization-and glyco-conjugation of these two pharmacophores is envisaged in unprecedented structures like N-glycosylated bis(1H-1,2,3 triazolyl)carbinols (BTACs), alkynyl-triazolylcarbinols (ATAC = ATAC(y)), or alkenyl-triazolylcarbinols (ATAC(e)). Such molecules were synthesized by Huisgen reaction of glycosyl azides, functional at the primary or anomeric position of O-protected (D)-ribose, (D)-galactose, or (D)-glucose units, with dialkynylcarbinols (DAC) and AAC substrates substituted in various manners at positions 1 and 3. These [2+3] cycloaddition dipolarophiles proved to react regio-selectively in standar click-chemistry conditions (CuSO4,5H2O + sodium ascorbate, in ethanol/water mixtures). The principle has been generalized to trialkynylcarbinol substrates, and the reactivity of the tris-(N-benzyl-1H-1,2,3-triazolyl)carbinol product, Taz3C-OH, was studied. In the presence of trifluoroacetic anhydride, the latter carbinol dissociates to the corresponding tris(triazolyl)carbenium - for which the term "trizyl cation" is coined, by analogy with the trityl cation-, whose SN1 reactivity with various O-, N-, S-and Cnucleophiles was found to selectively produce new structures, which are heterocyclic analogues of known or unknown triphenylmethane derivatives. Among the described new compounds, a few ATACs and BTACs were selected and tested for their inhibition activity towards enzymes (a-glucosidase and sphingosine kinase) or cytotoxicity towards tumor cells (adenocarcinome)

Laboratory bioassays for the assessment of anthelmintic property of plant extracts against gastrointestinal nematodes

The prevalence of parasite populations resistant to commercial broad-spectrum anthelmintic drugs has been dramatically increasing and suggests the need to adopt new prophylaxis strategies. In order to overcome this problem, validation of new anthelmintic molecules from plant extracts were performed and many in vitro and in vivo bioassays were published. In the present article, we will first review several isolation methods of different stages of parasite materials that are needed to perform in vitro bioassays. Then an overview of different techniques of in vitro and in vivo screening assays used to evaluate anthelmintic activity of the plant extracts against gastrointestinal nematodes is presented. Keywords: Laboratory bioassay, gastrointestinal nematodes, plant extract

Semigroup ideals with multiplicative semiderivations and commutativity of 3-prime near-rings

In the present paper, we introduce the notion of multiplicative semiderivation and prove some theorems in the setting of a semigroup ideal of a 3-prime near-ring admitting a multiplicative semiderivation. Thereby, it is shown that under appropriate additional hypotheses a near-ring must be a commutative ring. Furthermore, an example is given to illustrate that the 3-primeness hypothesis is not superfluous

Face Detection in a Mixed-Subject Document

Before you recognize anyone, it is essential to identify various characteristics variations from one person to another. among of this characteristics, we have those relating to the face. Nowadays the detection of skin regions in an image has become an important research topic for the location of a face in the image. In this research study, unlike previous research studies  related  to  this  topic  which  have  focused  on  images  inputs  data  faces,  we  are  more interested to the fields face detection in mixed-subject documents (text + images). The face detection system developed is based on the hybrid method to distinguish two categories of objects from the mixed document. The first category is all that is text or images containing figures having no skin color, and the second category is any figure with the same color as the skin. In the second phase the detection system is based on Template Matching method to distinguish among the figures of the second category only those that contain faces to detect them. To validate this study, the system developed is tested on the various documents which including text and image

Activité antibactérienne de l'huile essentielle d'origan et du carvacrol sur des souches d'Escherichia coli d'origine aviaire

Bacterial resistance to antibiotics and the search for new alternatives to antibiotics are of great importance in human and animal health. The main aim of this study was to evaluate the antibacterial pharmacodynamic properties of the essential oil of oregano as well as those of its major component, carvacrol, on strains of avian Escherichia coli resistant to antibiotics of current use in poultry (Colistin and Enrofloxacin). These properties were evaluated using standard agar diffusion and macro-dilution techniques for determination of Minimum Inhibitory Concentration (MIC). The results obtained showed a potent activity of the two tested products in comparison with the two antibiotics used in this study, giving the largest inhibition diameters which ranged respectively from 8 to 40 mm and from 14 to 30 mm for oregano essential oil (HE) and carvacrol. This was confirmed by the determination of the MIC which was 0.0031 % for oregano HE and 0.0625 % for its active ingredient. These results lead us to conclude that the use of oregano oil could be a good alternative to the evolving bacterial resistance. However, it would be interesting to confirm these results on living organisms in order to evaluate in vivo effectiveness of oregano essential oil and its active ingredients. Keywords: Essential oil of oregano, carvacrol, Escherichia coli, antibio-resistance, antibacterial activity, MIC, poultry.La résistance bactérienne aux antibiotiques et la recherche de nouvelles alternatives à ces derniers revêtent une grande importance en santé humaine et animale. L’objectif principal de cette étude a été d’évaluer les propriétés anti-bactériennes de l’huile essentielle de l’origan, ainsi que celle de son composant majoritaire le carvacrol, sur des souches d’Escherichia coli d’origine aviaire résistantes aux antibiotiques d’utilisation courante en aviculture (Colistin et Enrofloxacin). Ces propriétés ont été évaluées en utilisant des techniques usuelles de diffusion sur gélose et de macro-dilution pour la détermination de la concentration minimale inhibitrice. Les résultats obtenus ont permis de mettre en évidence une puissante activité anti-bactérienne des deux produits testés en comparaison avec les deux antibiotiques utilisés dans cette étude, en donnant les plus grands diamètres d’inhibition qui ont respectivement varié de 8 à 40 mm et de 14 à 30 mm quand pour l’huile essentielle (HE) d’origan et du carvacrol. Ceci a été confirmé par la détermination de la Concentration Minimale Inhibitrice (CMI) qui a été de 0,0031 % pour l’HE d’origan et de 0,0625 % pour son principe actif, le carvacrol. Ces résultats permettent de conclure que l’utilisation de l’huile d’origan ou de son constituant majoritaire le carvacrol, pourrait être une alternative efficace pour pallier aux résistances bactériennes sans cesse en évolution. Cependant, il serait intéressant de concrétiser ces résultats sur le vivant afin d’évaluer l’efficacité in-vivo de cette huile et de ses principes actifs. Mots-clés: Huile essentielle d’origan, carvacrol, Escherichia coli, antibio-résistance, activité anti-bactérienne, CMI, poulet

Antibacterial activity of essential oil of oregano and carvacrol on avian Escherichia Coli strains

Bacterial resistance to antibiotics and the search for new alternatives to antibiotics are of great importance in human and animal health. The main aim of this study was to evaluate the antibacterial pharmacodynamic properties of the essential oil of oregano as well as those of its major component, carvacrol, on strains of avian Escherichia coli resistant to antibiotics of current use in poultry (Colistin and Enrofloxacin). These properties were evaluated using standard agar diffusion and macro-dilution techniques for determination of Minimum Inhibitory Concentration (MIC). The results obtained showed a potent activity of the two tested products in comparison with the two antibiotics used in this study, giving the largest inhibition diameters which ranged respectively from 8 to 40 mm and from 14 to 30 mm for oregano essential oil (HE) and carvacrol. This was confirmed by the determination of the MIC which was 0.0031 % for oregano HE and 0.0625 % for its active ingredient. These results lead us to conclude that the use of oregano oil could be a good alternative to the evolving bacterial resistance. However, it would be interesting to confirm these results on living organisms in order to evaluate in vivo effectiveness of oregano essential oil and its active ingredients

Contribution à l'étude d'un Syndrome nerveux chez les ovins au niveau de la Commune d'Ait Ichou, Oulmès: Enquêtes Epidémiologiques

The present work is a contribution to the investigation of a neurological syndrome of unknown etiology (locally called Taghara which means seizures) that affects sheep in the Ait Ichou area.The study was first approached by interviewing farmers to collect epidemiological data.The results showed that (1) Disease prevalence was on average 4.76 %, with 67 % of flocks having a prevalence less than 10 % and only 6 % had prevalence between 40 and 66 %, (2) About 50 % of interviewed farmers ignored the disease cause and about 10 % attributed this disorder to plants intoxication or cold, (3) The disease appeared mainly during the cold season (72 % of cases), (4) Seizures are in 68% of cases triggered by external stimulus of the diseased animals, (5) More than 50 % of affected animals died following fall in ravines whereas the spontaneous recovery was observed only in 12 % of cases, (6) Sheep flocks spent most time on forest and are rarely supplemented and when a complementation was given, it is usually performed during mating (40 %) and lambing (30 %) seasons compared to 10 % during the period of disease occurrence, (7) The disease has no interference with reproduction, affects exclusively adult animals (>1 year) and both sexes, (8) The veterinarians in the area imputed the disease in part to plant poisoning but no specific treatment has yet been developed. Keywords: Sheep; Neurological diseases; interview; Ait-Ichou; Oulmès; Morocco.Le présent travail se propose d’étudier un syndrome nerveux d’étiologie inconnue (appelé localement Taghara qui signifie convulsions ou épilepsie) qui sévit chez les ovins à l’échelle de la Commune Rurale d’Ait Ichou, Cercle d’Oulmès. L’étude s’est déroulée entre février et juin 2013 et a été, dans un premier temps, basée sur des enquêtes auprès des éleveurs et des vétérinaires dans l’objectif de cerner les aspects épidémiologiques de la maladie. Les  enquêtes ont été effectuées par entretien direct auprès de 49 % des éleveurs alors que les vétérinaires de la zone ont été contactés par téléphone. Les résultats obtenus ont montré que (1) La prévalence moyenne de la maladie a été de 4,76 % (1,4 à 66 %), (2) La moitié des éleveurs ignore les causes de la maladie, (3) La maladie sévit essentiellement durant la période des pluies et les crises convulsives sont déclenchées par l’excitation des animaux, (4) Plus de 50 % des animaux atteints ont succombé et la guérison spontanée n’a été que rarement observée, (5) Les ovins ne sont que rarement complémentés, (6) La maladie n’interfère pas avec la reproduction, atteint exclusivement les adultes des deux sexes, (7) Les vétérinaires attribuent la maladie aux plantes toxiques.     Mots clés: Ovin; Maladies nerveuses; Enquêtes;  Ait Ichou; Oulmès; Maroc.   &nbsp