In vitro screening, homology modeling and molecular docking studies of some pyrazole and imidazole derivatives

International audienceA series of synthesized compounds based on pyrazole and imidazole skeletons prepared by palladium catalysts via a one-pot reaction was screened to determine their inhibitory potency against the pathogen fungus Fusarium oxysporum f.sp. albedinis (F.o.a) and four bacteria strains namely Micrococcus luteus, Bacillus subtilis, Staphylococcus aureus and Escherichia coli. The obtained result showed that these compounds exhibit an efficiency antifungal action. Whereas, they showed a very weak antibacterial activity. The structure-activity relationship (SAR) Analysis and lipophilicity study demonstrates the presence of a strong relation between the structure of the ligands and the antifungal activity. On the other hand, a homology modeling and molecular docking study was carried out on the most active compounds against F.o.a fungus, in order to understand and determine the molecular interactions taking place between the ligand and the corresponding receptor of the studied target

Characterization and Antimicrobial Activity of Nigella sativa Extracts Encapsulated in Hydroxyapatite Sodium Silicate Glass Composite

N. sativa is an interesting source of bioactive compounds commonly used for various therapeutic purposes. Associate its seeds extracts with biomaterials to improve their antimicrobial properties are highly demanded. This study aims to investigate the encapsulation of NS extracts in hydroxyapatite nanoparticle sodium silicate glass (nHap/SSG) scaffold. NS essential oil (HS) was extracted by hydrodistillation, while hexane (FH) and acetone extracts (FA) were obtained using Soxhlet extraction. (FH) was the most abundant (34%) followed by (FA) (2.02%) and (HS) (1.2%). GC-MS chromatography showed that the (HS) contained beta cymene, alpha thujene, β-pinene and thymoquinone, while (FH) had mostly fatty acids and (FA) decane, 2.9-dimethyl, benzene 1,3,3-trimethylnonyl and beta cymene. Loaded nHap/SGG scaffolds with various amount of (FH), (HS) and (FA) at 1.5, 3, and 6 wt%; were elaborated then characterized by ATR-FTIR, X-ray and SEM techniques and their antimicrobial activity was studied. Samples loaded with 1.5 wt% HE was highly active against C. albicans (19 mm), and at 3 wt% on M. luteus (20 mm) and S. aureus (20 mm). Additionally, loaded scaffolds with 1.5 wt% AE had an important activity against M. luteus (18.9 mm) and S. aureus (19 mm), while the EO had low activities on all bacterial strains. The outcome of this finding indicated that loaded scaffolds demonstrated an important antimicrobial effect that make them promising materials for a wide range of medical applications

IN VITRO BIODEGRADATION OF OLEUROPEIN BY LACTOBACILLUS PLANTARUM FSO175 IN STRESS CONDITIONS (pH, NaCl AND GLUCOSE)

International audienceThe objective of this work is to study the oleuropein (OLP) biodegradation by a strain of Lactobacillus plantarum FSO175 under conditions (pH 4.5, NaCl 5% and glucose 1%), during 7 days of incubation at 30 °C, in modified MRS broth containing OLP as carbon source. The results obtained, by HPLC analyses, showed that the biodegradation of OLP by L. plantarum FSO175, is accompanied with increase of hydroxytyrosol (HT) content and acidity values. The yields of OLP degradation and HT accumulation are depending on carbon sources, stress conditions and time of incubation. So that, the drastic reduction in OLP biodegradation, obtained at pH 6.7 (trial B), decreased significantly (p <0.05) in presence of NaCl 5% (trial D) and with glucose 1% (trial C). Indeed, the OLP biodegradation rate was maximal at pH 4.5 (trial E) and was higher even with NaCl 5% (trial F). In contrast, in presence of combined stress conditions (glucose 1%, pH 4.5 and NaCl 5%: trial G), the biodegradation of OLP decreased significantly (p <0.05). The effectiveness of the strain L. plantarum FSO175 in OLP biodegradation leading to variable yields of HT production, revealed its promising perspectives as starter culture, under controlled stress conditions of pH 4.5 and NaCl 5%, allowing the production of green table olives rich of HT, the main antioxidant highly desired in foods