No abstract

No abstract

No abstract

No abstract

No abstract

Abstract:The chemical composition of essential oils obtained by hydrodistillation from aerial parts of Ocimum basilicum, Ocimum canum and Ocimum gratissimum from Benin as affected by harvesting time, were analyzed by GC-FID (Gas chromatography-Flame ionization detector) and GC-MS (Gas chromatographyMass spectrometry). Based on the composition analysis, major components were as follows: estragol (43.0 -44.7 %) and linalool (24.6 -29.8 %) in O. basilicum oils; carvacrol (12.0 -30.8 %) and p-cymene (19.5 -26.2 %) in O. canum oils; thymol (28.3-37.7 %) and γ-terpinene (12.5-19.3 %) in O. gratissimum oils. Disc diffusion and broth microdilution assays were used to evaluate the antibacterial activity of essential oils and their main components against two foodborne bacteria, Listeria monocytogenes and Salmonella enterica serotype Typhimurium. The tested oils and their components exhibited notable antimicrobial activities against L. monocytogenes and S. Typhimurium. The O. canum and O. gratissimum oils collected at 7h and 19h showed significant higher activities against L. monocytogenes and S. Typhimurium (MICs and MBCs 0.34 -2.5 μL/ mL) (p < 0.05), whereas O. basilicum showed lower activity (MICs and MBCs 2.0 -8.0 μL/mL) at any daytime of harvest, the weakest being at 19h (MIC and MBC 12.0 -32.0 μL/mL). The daytime of harvest can influence the composition of oils and their activities on bacteria.

Six 1,3,4-thiadiazolines derivatives were synthesized by cyclization of thiosemicarbazones under acetylating condition with yields going from 27 to 94%. The products purity was confirmed by LC/MS (Mass Spectrometry Coupled with High-Performance Liquid Chromatography) and they were characterized using spectrometry IR, NMR 1 H and 13 C (Nuclear Magnetic Resonance). These compounds were then tested in vitro on Trypanosoma brucei brucei according to the "LILIT, Alamar Blue" method to estimate their trypanocidal activity. 1,3,4-thiadiazoline 6 (IC 50 = 38,79 µM) was the most active of all compounds.

No abstract