Digital Repository for University of Tripoli

The antibacterial activity of peppermint oil and different extracts of Mentha piperita against some Gram-positive and Gram-negative bacterial strains was evaluated in the present research work by agar well diffusion method. It was found that the distilled concentrations of essential oil inhibited the growth of microorganisms and the results were comparable with those of antibiotic gentamycin. Essential oils showed a wider spectrum of activity but less strong inhibition as compared to the investigated commercial antibiotic. Minimum inhibitory concentrations (MICs) for the bacterial species ranged from 0.4% to 0.7% v/v. The oil and extracts also exhibited significant antioxidant activity and the oil showed about half potency when compared to the standard BHT. These results indicated the strong antibacterial and antioxidant activities of peppermint oil but additional investigations need to be performed in order to confirm the safety of these concentrations (MIC) for human consumption. Peppermint oil could be used as a good conservation agent by inhibiting some food borne pathogens. arabic 8 English 54
Rajinder Singh, Muftah A. Shushni, Asma Belkheir(5-2015)

Marine fungi are a promising source for bioactive compounds [1]. The fungal strain 222 has been isolated from wood collected at the coast of the Greifswalder Bodden, Baltic Sea, Germany and produces structurally new naphthalenone derivatives, balticols A to F. They possess antiviral activities [2]. Since other naphthalene compounds are known for their anti-inflammatory activities we investigated whether the balticols have an influence on inflammatory immune cells. Balticols (1 and 10µg/ml) were added to rat mononuclear cells (F344-MNC) which were cultured alone or together with H9c2-cardiomyocytes. The latter represents a model of inflammation similar as observed after myocardial infarction. MNC's were collected after 48h and analyzed for T-, B-, NK-, TH-cells and CTL's by flow cytometry. Dexamethasone (Dexa, 10–9 mol/l) served as positive control. None of the balticols except balticol E changed the number of control MNC's. The proportion of T-cells was decreased by balticol B and D, but ICAM-1+T-cells increased. Balticol D decreased TH- and increased B-cells as Dexa which additionally decreased CTL's. None of the substances influenced NK cells. After co-culture with cardiomyocytes TH-cells were decreased while CTL's and ICAM-1+T-cells increased. Balticol D partly anticipated the decrease of TH. Balticol E decreased T-cells, especially TH-cells, but stimulated ICAM-1+T-cells. Dexa anticipated the increase of CTL's, had no influence on the proportion of TH-cells and diminished ICAM-1+T-cells. In summary, balticols B, D and E influence unstimulated MNC's. Unambiguous anti-inflammatory effects were detected using Dexa and balticol E which exerts its effect due reduction of T-cells. arabic 14 English 83
B. Haertel, Muftah A. Shushni, Ulrike Lindequist(1-2010)

The antibiotic elansolid C1 (8) was isolated from Chitinophaga sancti strain FxGBF13 after fermentation in the presence of anthranilic acid. Remarkably, 8 was also obtained by addition of anthranilic acid to a crude fermentation extract containing the macrolide elansolid A2 (1*). This Michael-type conjugate addition allowed us to generate 21 new derivatives of elansolid C1 (9-29) by using various nucleophiles. Biological activities of all derivatives were evaluated against Staphylococcus aureus, Micrococcus luteus, and the mouse cell line L929. arabic 9 English 74
Heinrich Steinmetz, Wiebke Zander, Muftah A. M. Shushni, Rolf Jansen, Klaus Gerth, Richard Dehn, Gerald Dräger, Andreas Kirschning, Rolf Müller(8-2012)

Because of the evolving resistance of microorganisms against existing antibiotics, there is an increasing need for new ones, not only in human, but also in veterinary medicine. The dichloromethane extract of a fungal strain of the genus Lophiostoma, isolated from driftwood collected from the coast of the Baltic Sea, displayed antibacterial activity against some fish pathogenic bacteria. Ergosterol epoxide (1), cerebroside C (2) and oxasetin (3) were isolated from the extract and structurally elucidated on the basis of spectroscopic data and chemical evidence. Compound 3 exhibited in vitro activity against Vibrio anguillarum, Flexibacter maritimus and Pseudomonas anguilliseptica with minimal inhibitory concentrations of 12.5, 12.5 and 6.25 microg/mL, respectively. Molecular docking studies were performed to understand the interaction of compound 3 with different macromolecular targets. Analysis of in silico results, together with experimental findings, validates the antimicrobial activity associated with compound 3. These results may be exploited in lead optimization and development of potent antibacterial agents. arabic 23 English 137
Muftah A Shushni, Faizul Azam, Ulrike Lindequist, (9-2013)

A new 12-membered macrolide, balticolid (1) was isolated from the EtOAc extract of the culture broth of fungal strain 222 belonging to the Ascomycota, which was found on driftwood collected from the coast of the Greifswalder Bodden, Baltic Sea, Germany. The structure of balticolid was determined to be (3R,11R), (4E,8E)-3-hydroxy-11-methyloxacyclododeca-4,8-diene-1,7-dione using extensive spectral data as well as the modified Mosher ester method. Balticolid (1) displayed anti-HSV-1 activity with an IC₅₀ value of 0.45 μM.A new 12-membered macrolide, balticolid (1) was isolated from the EtOAc extract of the culture broth of fungal strain 222 belonging to the Ascomycota, which was found on driftwood collected from the coast of the Greifswalder Bodden, Baltic Sea, Germany. The structure of balticolid was determined to be (3R,11R), (4E,8E)-3-hydroxy-11-methyloxacyclododeca-4,8-diene-1,7-dione using extensive spectral data as well as the modified Mosher ester method. Balticolid (1) displayed anti-HSV-1 activity with an IC₅₀ value of 0.45 μM. arabic 16 English 92
Muftah A. Shushni, R Singh, R Mentel, U Lindequist(9-2011)

Six new naphthalenone derivatives, balticols A-F and the known metabolite altechromone A were isolated from the AcOEt extract of the culture broth of fungal strain 222 belonging to the Ascomycota, which was found on driftwood collected at the coast of the Greifswalder Bodden, Baltic Sea, Germany. All structures were elucidated on the basis of NMR spectroscopic data and mass spectrometric analyses. The balticols were found to exhibit inhibitory activity against influenza virus A and herpes simplex virus. The most potent antiviral activity was observed for balticol E with an IC(50) value of 0.01 microg/ml against Herpes simplex virus type I. arabic 14 English 83
Muftah A. Shushni, Renate Mentel, Ulrike Lindequist, Rolf Jansen(2-2009)

Technology is all around us and it’s changing rapidly, expanding Internet access has had huge impacts on everyday lives as people do everything on their phones and computers. The widespread growth in the use of digital computers, have an increasing need to be able to communicate with machines in a simpler manner. One of the main tasks that can simplify communication with machines is speech recognition. In this work, we introduce the Arabic speech commands database that contains six Arabic control order words and Arabic spoken digits. The created database is used to analyze and compare the recognition accuracy and performance of three recognition techniques which are, Wavelet Time Scattering feature extraction with Support Vector Machine (SVM) classifier, Wavelet Time Scattering feature extraction with Long Short-Term Memory (LSTM) classifier, and Mel-Frequency Cepstrum Coefficients (MFCC) feature extraction with K-Nearest Neighbor (KNN) classifier. Finally, the experimental results show that the most accurate prediction of the database commands was 98.1250% given by Wavelet Time Scattering feature extraction and LSTM classifier and the fastest training time for the database was 144 minutes given by MFCC and KNN classifier. arabic 5 English 42
Osama A. Alkishriwo, Lina Tarek Benamer(12-2020)

Denoising of chirp based signals is a challenging problem in signal processing and communications. In this paper, we propose a suitable denoising algorithm based on the discrete linear chirp transform (DLCT), which provides local signal decomposition in terms of linear chirps. Analytical expression for the optimal filter response is derived. The method relies on the ability of the DLCT for providing a sparse representation to a wide class of broadband signals like chirp signals. Simulation results show the efficiency of the proposed method, especially for mono-component chirp signals.
Osama A. Alkishriwo(12-2020)