The present study investigates deep eutectic solvents (DESs) as potential media for enzymatic hydrolysis. A series of ternary ammonium and phosphonium-based DESs were prepared at different molar ratios by mixing with aqueous glycerol (85%). The physicochemical properties including surface tension, conductivity, density, and viscosity were measured at a temperature range of 298.15 K – 363.15 K. The eutectic points were highly influenced by the variation of temperature. The eutectic point of the choline chloride: glycerol: water (ratio of 1: 2.55: 2.28) and methyltriphenylphosphonium bromide:glycerol:water (ratio of 1: 4.25: 3.75) is 213.4 K and 255.8 K, respectively. The stability of the lipase enzyme isolated from porcine pancreas (PPL) and Rhizopus niveus (RNL) toward hydrolysis in ternary DESs medium was investigated. The PPL showed higher activity compared to the RNL in DESs. Molecular docking simulation of the selected DES with the substrate (p-nitrophenyl palmitate) toward PPL was also reported. It is worth noting that ternary DES systems would be viable lipase activators in hydrolysis reactions.
In this work, the preparation of some new oxazolidine and thiazolidine derivatives has been conducted. This was done over two steps; the first step included the synthesis of Schiff bases A1-A5 in 72-88% yields by the condensation of isonicotinic acid hydrazide and aldehydes. The second step includes the cyclization of derivatives A1-A5 with glycolic acid and thioglycolic acid to obtain the desired products, oxazolidine derivatives B1-B5 (44-60% yields) and thiazolidine derivatives C1-C5 (41-61% yields), respectively. The structure of the prepared compounds was characterized using FT-IR, 1H NMR, and 13C NMR spectroscopy. Some of the produced compounds were tested for antioxidant properties.
Lignans are natural products widely distributed in the plant kingdom. They are composed of two β-β-linked phenylpropane (shikimate-derived biogenetic subunits). Although the backbone of lignans is composed of phenylpropane units, there is enormous diversity in the structure of lignans leading to different classes of lignans, such as γ-butyrolactone derivatives, eg. Hymatairesinol, bicyclooctadiene derivatives, e.g. pinoresinol, tetrahydrofuran derivatives e.g.lariciresinol, di-arylbutandiol derivatives, e.g. secoisolariciresinol. Introduction of a further carbon –carbon linkage leads to a class of lignans collectively known as cyclolignans such as tetrahydro-naphthalene derivatives, for example podophyllotoxin. Lignans ha
... Show MoreThe modern and contemporary history of Libya has attracted the attention of researchers during the nineties of the last century and beyond.
The subject of ((Jewish activity in Libya 1911 AD - 1951 AD)), and the nature of follow - up economic and social activities and political participation has remained poor in terms of study and follow - up, because of the scarcity of sources, especially documentary ones. The research will reveal within its axes the most important of these activities.
Condensation of 1,2- dibromo ethane with para hydroxy benzoic acid gave 1,2-Ethane-bis- 4-oxybenzoic [1]. This Compound was converted with the thionyl chloride to give 1,2-Ethane-bis- 4-oxybenzoyl chloride [2]. Reaction of compound [2] with thiosemicarbizades gave 1,2-Ethanebis[4-oxybenzoyl-thiosemicarbazide] [3] and opteined 1,2-Ethane-bis[3-mercapto-5-phenoxy- 1,2,4-triazole] [4] from treatment compound [3] with NaOH (4%) .The new compounds 1,2- Ethane-bis[3-(substituted thioacyl)-4-(substituted acyl)-5 phenoxy-1,2,4-triazole] [5a-d] and 1,2- Ethane-bis[3-(substituted alkylthio)-5 phenoxy-1,2,4-trizole] [5e-f] derived from compound [4] were synthesized and characterized by physical and spectral data. All the compounds [4], [5a-d] and [5e-
... Show MoreNew 2-amino thiazole ,oxodiazole, sulphonilamide and diazin derivatives of N-(α-chloro aceto)-3-(tolyl imino)-5-bromo-2-oxo-indole(2) have been synthesized .The preparation process started by the reaction of 5-bromo isatin with P-toluidine in the presence of glacial acetic acid and dimethylformamide(DMF) as a solvent to give 3-(tolyl imino)5-bromo-1H-indole-2-one.(1), Compound (1) with sodium hydride in dimethylformamide(DMF) at 0C0 gave a suspension of the sodium salt of Schiff base derivative and subsequent reaction with monochloroacetylchloride obtained the intermediate compound(2).Compound(2) was reacted with different reagents in four routes.The first route involved direct reaction with substituted 2-aminobenzothiazole u
... Show MoreBiomedical alloy 316L stainless steel enhancing to replace biological tissue or to help stabilize a biological structure, such as bone tissue, enhancing were coated with deposition a thin layer of silver nanoparticles as anti-bacterial materials by using DC- magnetron sputtering device. The morphology surface of The growth nanostructure under the influence of different working pressure were studied by atomic force microscope. The average grain size decrease but roughness of the silver thin layer was increased with‖ ―increasing the working pressure. The thickness of silver thin layer was increased from 107 nm at 0.08 mbar to 126 nm at 1.1 mbar. Antimicrobial activity of silver thin layers at different working pressure were studied. Th
... Show MoreThe development of new cephalosporins with improved activity against resistant microbes, such as, MRSA (methicillin resistant Staph. aureus), P. aeruginosa, is of high potential. Chemical synthesis of two new series of thiadiazole linked to cysteine (series 1) and cephalosporins containing thiadiazole linked to cysteine through disulfide bond (series 2) were achieved. The chemical structures of the synthesized compounds were confirmed using spectral (FT-IR, 1H-NMR) and elemental microanalysis. The incorporation of privileged chemical moieties, such as, thiadiazole, Schiff base, cysteine and sulfonamide, has been found to have great contribution to the antimicrobial activities. Compounds of series 1 (1
... Show MoreZerumbone is a well-known compound having anti-cancer, anti-ulcer, anti-inflammatory and anti-hyperglycemic effects. During its use for the disease treatment, the membrane of erythrocyte can be affected by consumption of this bioactive compound. The current study was the first report of investigation of the hemolytic activities on human erythrocytes and cytotoxic profile of zerumbone. The toxicity of zerumbone on human erythrocytes was determined by in vitro hemolytic assay. Brine shrimp lethality assay was used to evaluate the cytotoxic effect of zerumbone at concentrations 10, 100 and 1000 μg/mL. The human erythrocyte test showed no significant toxicity at low concentrations, whereas hemolytic effect was amplified up to 17.5 % at
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