108 research outputs found
Identification of an antiviral compound isolated from Pistacia lentiscus
No full textThis study screened mastic gum (Pistacia lentiscus L.) for antiviral activity against herpes simplex virus type 2 (HSV-2), coxsackievirus type B3, and adenovirus type 5. The organs of this plant (leaves, stem, and seed) were macerated sequentially using solvents of increasing polarity (hexane, dichloromethane, ethyl acetate, and methanol). Only the methanol extract of stem exhibited significant activity against HSV-2. This extract showed anti-HSV-2 activity with a selectivity index of 51 (50% cytotoxic concentration = 186 μg/mL; 50% inhibitory concentration = 3.63 μg/mL), and demonstrated direct inhibition against this virus with a virucidal selectivity index of 620 (50% virucidal concentration = 0.30 μg/mL). A bio-guided assay involving thin-layer chromatography led to the isolation of two active compounds, which have been identified as dammaradienone and dammaradienol using high-performance liquid chromatography-diode array detection coupled with electrospray ionization mass spectrometry. P. lentiscus has been widely studied for other biological activities. However, to our knowledge, this is the first report of P. lentiscus L. exhibiting antiviral activity
Dialogue Homme-Machine pour l'accès à l'information géographique, Accès intelligent aux documents multimédias sur l'Internet
No full text@inproceedings{CN-LIMAM-2002, author = {Limam, M. O. A.}, title = {Dialogue Homme-Machine pour l'accès à l'information géographique, Accès intelligent aux documents multimédias sur l'Internet}, booktitle = {Journées Francophones D'Accès Intelligent aux Documents Multimédias sur l'Internet, Media Net}, year = {2002}, address = {Sousse, Tunisie}, pages = {105-116} }National audienc
Cyclo-(His,Leu): A new microbial diketopiperazine from a terrestrial Bacillus subtilis strain B38
No full textIn continuation of our search for bioactive secondary metabolites from terrestrial Bacillus spp., a new microbial diketopiperazine, cis-cyclo-(His,Leu) (1) was isolated from the ethyl acetate extract of a strain B. subtilis B38, together with cis-cyclo-(Phe,Phe) (2), tryptophane (3), cis-cyclo-(Leu,Tyr) (4), cis-cyclo-(Trp,Tyr) (5) and macrolactin A (6). The chemical structures of the isolated compounds were identified by comparison of their 1D, 2D NMR and HRESIMS data with authentic spectra and literatures. To the best of our knowledge, this is the first time that cyclo-(His,Leu) has been isolated from natural products
Isolation and identification of an antibacterial compound from Diplotaxis harra (Forssk.) Boiss
No full textThe emergence of the antibiotic resistance is an ongoing problem in public health, and therefore the search for new natural molecules represents an alternative to synthetic drugs. The aim of this study was to test the antibacterial activity of ten Mediterranean plants (Diplotaxis harra, Ecballium elaterium, Pergularia tomentosa, Myrtus communis, Solanum villosum, Solanum sodomaeum, Peganum harmala, Lepidium sativum, Pistacia lentiscus, and Calendula arvensis) against seven pathogenic bacteria (Staphylococcus aureus, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Klebsiella sp., Salmonella enteritidis, and Bacillus cereus) using the disk diffusion method, in order to isolate and identify the active compound(s). Dichloromethane extract of D. harra flower showed the best activity against S. aureus and L. monocytogenes (MIQ = 30 μg/disk and 15 μg/disk, respectively). This extract was submitted to a bio-guided purification using Thin Layer Chromatography (TLC)-bioautography, and an antibacterial fraction (MIQ = 2 μg/disk) was isolated. The active fraction was characterized by RP-HPLC-DAD-ESI-MSn and GC–MS. Sulforaphane, an isothiocyanate known for its anti-cancer, antioxidant, and anti-inflammatory properties, was identified as antibacterial agent in D. harra for the first time. Due to its high antibacterial activity, sulforaphane could be considered a good candidate for the selection of new natural antibacterial molecules
Production of Anti-Methicillin-Resistant Staphylococcus Activity from Bacillus subtilis sp Strain B38 Newly Isolated from Soil
No full textB38 bacterial strain, isolated from Tunisian soil showed a strong antimicrobial activity. Based on biochemical characterization and 16S rDNA sequence analysis, B38 strain was identified as Bacillus subtilis. Cell culture supernatant showed antibacterial activity against clinical isolates of methicillin-resistant Staphylococcus species and several Gram-positive and Gram-negative bacteria. Antifungal activity against phytopathogenic fungi was also observed. Antibacterial activity production started at early exponential growth phase, and maximum activity was reached at the stationary phase. This antibacterial activity was neither affected by proteases, lipase, and organic solvents, nor by surfactants. It was stable over a wide pH range and still active after autoclaving at 121 degrees C during 20 min. Thin layer chromatography followed by bioautography assay allowed the detection of four active spots with R(f) values of 0.30, 0.47, 0.70, and 0.82. The single spot with R(f) 0.30 showed antifungal activity, whereas the spots with R(f) values of 0.47, 0.70, and 0.82 exhibited antibacterial activity
Intéraction bimodale pour l'accès à l'information
No full text@inproceedings{CN-LIMAM-2002-2, author = {Limam, M. O. A. and Gaio, M.}, title = {Intéraction bimodale pour l'accès à l'information}, booktitle = {14eme conférence Francophone sur l'Intéraction Homme-Machine (IHM'02)}, year = {2002}, address = {Poitiers, France} }National audienc
Antioxidant, antibacterial, and antileishmanial potential of Micromeria nervosa extracts and molecular mechanism of action of the bioactive compound
No full textAims: This study aimed to determine the antibacterial and antileishmanial potential of Micromeria nervosa extracts. The identification of the
antileishmanial compound and the study of its molecular mechanism of action have also been undertaken.
Methods and results: Ethanol extract showed high polyphenol content and diethyl ether extract exhibited high DPPH scavenging and low
beta-carotene bleaching activity (IC50 = 13.04 ± 0.99 and 200.18 ± 3.32 μg mL−1 , respectively). However, diethyl ether extract displayed high
antibacterial activity against Gram-positive strains including methicillin-resistant Staphylococcus aureus (MIC = 31.25 μg mL−1 ), Staph. aureus
ATCC6538 (MIC = 62.5 μg mL−1 ), and Listeria monocytogenes ATCC 19115 (MIC = 125 μg mL−1 ), as well as high antileishmanial activity against
the promastigote forms of L. infantum and L. major (IC50 = 11.45 and 14.53 μg mL−1 , respectively). The active compound was purified using
bioassay-guided fractionation and thin layer chromatography, and identified as ursolic acid using high-performance liquid chromatography coupled
with a photodiode array and mass spectrometry. The purified compound was strongly inhibitory against the promastigote and amastigote forms
of L. infantum and L. major (IC50 = 5.87 and 6.95 μg mL−1 versus 9.56 and 10. 68 μg mL−1 , respectively) without overt cytotoxicity against
Raw 264.7 macrophage cells (SI = 13.53 and 11.43, respectively). The commercial compound (ursolic acid) showed similar activity against
amastigotes and promastigotes forms of L. infantum and L. major. Moreover, its molecular mode of action against leishmaniasis seems to
involve the expression of the ODC and SPS genes involved in thiol pathway.
Conclusion: Extracts of M. nervosa can be considered as a potential alternative to antimicrobial and antileishmanial drugs
Construction and specification of spatial configurations in a geographical information retrieval context
No full text@inproceedings{CI-LIMAM-2004, author = {Limam, M. O. A. and Gaio G.}, title = {Construction and specification of spatial configurations in a geographical information retrieval context}, booktitle = {proceedings of the 12th International Conference on Geoinformatics (Geoinformatics'04)}, year = {2004}, address = {Gavle, Sweden}, month = {June} }International audienc
Feedback sémantique dans un environnement de recherche d'informations géographiques
No full text@inproceedings{CN-LIMAM-2003, author = {Limam, M. O. A. and Dumoncel, F. and Gaio, M.}, title = {Feedback sémantique dans un environnement de recherche d'informations géographiques}, booktitle = {15eme conférence francophone sur l'Interaction Homme-Machine (IHM'03)}, year = {2003}, address = {Caen, France}, month = {novembre} }National audienc
Génération de texte guidée par un focus : description textuelle de schémas géographiques
No full text@inproceedings{CN-LIMAM-2002-3, author = {Limam, M. O. A. and Gaio, M.}, title = {Génération de texte guidée par un focus : description textuelle de schémas géographiques}, booktitle = {5ème colloque international sur le document électronique (CIDE'02)}, year = {2002}, address = {Hammamet, Tunisie}, pages = {289-308} }National audienc
- …
