Ru(ii)-N-heterocyclic carbene complexes: synthesis, characterization, transfer hydrogenation reactions and biological determination.

A series of ruthenium(ii) complexes with N-heterocyclic carbene ligands were successfully synthesized by transmetalation reactions between silver(i) N-heterocyclic carbene complexes and [RuCl2(p-cymene)]2 in dichloromethane under Ar conditions. All new compounds were characterized by spectroscopic and analytical methods. These ruthenium(ii)-NHC complexes were found to be efficient precatalysts for the transfer hydrogenation of ketones by using 2-propanol as the hydrogen source in the presence of KOH as a co-catalyst. The antibacterial activity of ruthenium N-heterocyclic carbene complexes 3a-f was measured by disc diffusion method against Gram positive and Gram-negative bacteria. Compounds 3d exhibited potential antibacterial activity against five bacterial species among the six used as indicator cells. The product 3e inhibits the growth of all the six tested microorganisms. Moreover, the antioxidant activity determination of these complexes 3a-f, using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) as reagent, showed that compounds 3b and 3d possess DPPH and ABTS antiradical activities. From a concentration of 1 mg ml-1, these two complexes presented a similar scavenging activity to that of the two used controls gallic acid (GA) and butylated hydroxytoluene (BHT). From a concentration of 10 mg ml-1, the percentage inhibition of complexes 3b and 3d was respectively 70% and 90%. In addition, these two Ru-NHC complexes exhibited antifungal activity against Candida albicans. Investigation of the anti-acetylcholinesterase activity of the studied complexes showed that compounds 3a, 3b, 3d and 3e exhibited good activity at 100 µg ml-1 and product 3d is the most active. In a cytotoxicity study the complexes 3 were evaluated against two human cancer cell lines MDA-MB-231 and MCF-7. Both 3d and 3e complexes were found to be active against the tested cell lines showing comparable activity with examples in the literature.

Statistical versus artificial intelligence -based modeling for the optimization of antifungal activity against Fusarium oxysporum using Streptomyces sp. strain TN71.

A Streptomyces sp. strain TN71 was isolated from Tunisian Saharan soil and selected for its antimicrobial activity against phytopathogenic fungi. In an attempt to increase its anti-Fusarium oxysporum activity, GYM+S (glucose, yeast extract, malt extract and starch) culture medium was selected out of five different production media. Plackett-Burman design (PBD) was used to select yeast extract, malt extract and calcium carbonate (CaCO3) as parameters having significant effects on antifungal activity, and a Box-Behnken design was applied for further optimization. The analysis revealed that the optimum concentrations for the anti-F. oxysporum activity of the tested variables were yeast extract 5.03g/L, malt extract 8.05g/L and CaCO3 4.51g/L. Artificial Neural Networks (ANNs): the Multilayer perceptron (MLP) and the Radial basis function (RBF) were created to predict the anti-F. oxysporum activity. The comparison between experimental and predicted outputs from ANN and Response Surface Methodology (RSM) were studied. The ANN model presents an improvement of 14.73%. To our knowledge, this is the first work reporting the statistical versus artificial intelligence -based modeling for the optimization of bioactive molecules against mycotoxigenic and phytopathogenic fungi.

Post-concussive syndrome after mild head trauma: epidemiological features in Tunisia.

BACKGROUND: Minor head injury is one of the major diagnoses requiring management in emergency departments (ED) but its squeals are not well studied in our country. OBJECTIVE: To describe the prevalence of post-concussive syndrome and its impacts on life activities, up to 6 months of follow-up, among patients having a minor head injury and discharged from ED. METHODS: A prospective bi-centric study including adults having a minor head trauma and consenting to be followed up to 6 months after discharge. The Rivermead Post-Concussion Symptoms Questionnaire (RPQ) was used at baseline, after 15 days, at 1 month, at 3 months and at 6 months post-injury to assess concussive symptoms. We also used the Rivermead Head Injury Follow-up Questionnaire (RHFUQ) to describe impacts of minor head trauma on life activities. RESULTS: There were 130 consenting patients at baseline interview. Proportion of patients describing post-concussive symptoms at baseline was 71/130. At 6 months of follow-up, post-concussive syndrome was diagnosed among 21.4 % of participants. Sustaining symptoms at 6 months post-injury were mainly anger and irritability (12.5 %). Correlations between high RPQ sum rates since 15 days' post-injury call and the sum total rates of RHFUQ were significant. The major significant impact of minor head trauma at 6 months of follow-up was among domestic activities. CONCLUSION: The two most important findings of this study were the huge proportion of patients having minor head injury and discharged from ED without any explanation of possible symptoms after head trauma and the unknown impacts on life activities.

Efficient role of BacTN635 on the safety properties, sensory attributes, and texture profile of raw minced meat beef and chicken breast.

Bacteriocin BacTN635, produced by Lactobacillus plantarum sp. TN635, was purified and characterised in previous work. In this study we report the biotechnological application of this bacteriocin as a biopreservative during storage at 4°C of raw minced meat beef and chicken breast. Overall, the results obtained showed that the addition of the semi-purified BacTN635 at 500 or 1000 AU g(-1) in raw minced meat beef and chicken breast can delay the proliferation of spoilage microorganisms, suppress the growth of the pathogenic microorganism Listeria monocytogenes, improve sensory quality, texture attributes, and extend the shelf-life of these two meat products during refrigerated storage. BacTN635 at 1000 AU g(-1) could extend the shelf-life, and the meat showed good sensory characteristics. Therefore, treatment with semi-purified BacTN635 can be used as a safe method for preservation of raw minced meat beef and chicken breast.